Talk:2015 Group 5 Project
Group Assessment Criteria
- The key points relating to the topic that your group allocated are clearly described.
- The choice of content, headings and sub-headings, diagrams, tables, graphs show a good understanding of the topic area.
- Content is correctly cited and referenced.
- The wiki has an element of teaching at a peer level using the student's own innovative diagrams, tables or figures and/or using interesting examples or explanations.
- Evidence of significant research relating to basic and applied sciences that goes beyond the formal teaching activities.
- Relates the topic and content of the Wiki entry to learning aims of cell biology.
- Clearly reflects on editing/feedback from group peers and articulates how the Wiki could be improved (or not) based on peer comments/feedback. Demonstrates an ability to review own work when criticised in an open edited wiki format. Reflects on what was learned from the process of editing a peer's wiki.
- Evaluates own performance and that of group peers to give a rounded summary of this wiki process in terms of group effort and achievement.
- The content of the wiki should demonstrate to the reader that your group has researched adequately on this topic and covered the key areas necessary to inform your peers in their learning.
- Develops and edits the wiki entries in accordance with the above guidelines.
--Z3417843 (talk) 22:01, 22 March 2015 (EST) Hey everyone! I'm Carl and I'm looking forward to meeting you all next week in the lab. I did Embryology last semester and so if you need any help regarding the website, you can ask me and I'll try my best to help you (unless of course you're tech savvy hahaha) Anyway, we should decide on a topic before any of the good ones are gone. Looking at the extracellular matrix pages on this website, I think we are gonna have to choose among these topics: collagen, elastin, proteoglycans, fibronectin, laminin. I think everyone would want to choose collagen since it looks like it's the one with the most info. Also, when you reply on discussion, I suggest you add your signature first then your reply (not the other way around. Way too confusing). That's all from me for now. Hope you all had a great weekend!
Hi guys! I'm Bek. Thanks for offering Carl. Sorry for the late reply. We should choose our topic tomorrow so we have options. Collagen and elastin have a already been taken, leaving us with proteoglycans, fibronectin, laminin. Looking around i think either fibronectin or laminin have a bit more information and subtopics available. I would be happy with any of the three, what does everyone else think? --Z3462921 (talk) 23:47, 24 March 2015 (EST)
--Z3417843 (talk) 21:17, 25 March 2015 (EST) Hi all! I think we should go with Laminin. I put laminin as our heading just so that we already have a topic. We can always change anyway. And he did say there's a chance he might change what we write about because if we divide the topics by ECM structures, there won't be enough for all groups. So, I don't know. Anyway, feel free to change it if you want to do fibronectin instead. Totally fine with me. :)
--Z3461763 (talk) 17:23, 26 March 2015 (EST)Heyy all! I'm Chala! Sorry for the late reply. Only just realised the discussion had been opened up. I'm ok with whatever topic we choose (looks like Laminin it is!). :D
--Z3461763 (talk) 18:05, 26 March 2015 (EST)Just confirming, the four headings we've decided on are Structure, Function, Diseases and Current Research. :) The following lists who agreed to research what. Have fun :)
Jose - Structure Carl - Function Rebekah - Diseases Chala - Current Research
--Z5050800 (talk) 05:21, 2 April 2015 (EST) Individual assessment 3 "...The reference along with your description should then be pasted on both your group discussion page (?!?!?) and your own personal page."
Article 1: “Origin and Evolution of Laminin Gene Family Diversity”: Laminins are a family of multidomain glycoproteins that are important contributors to the structure of metazoan extracellular matrices. To investigate the origin and evolution of the laminin family, the researchers characterized the full complement of laminin-related genes in the genome of the sponge, Amphimedon queenslandica. Five Amphimedon laminin-related genes possess the conserved molecular features, and most of the domains found in bilaterian laminins, but all display domain architectures distinct from those of the canonical laminin chain types known from model bilaterians. This finding prompted to perform a comparative genomic analysis of laminins and related genes from a choanoflagellate and diverse metazoans and to conduct phylogenetic analyses using the conserved Laminin N-terminal domain in order to explore the relationships between genes with distinct architectures. Together, results suggest that gene duplication and loss and domain shuffling and loss all played a role in the evolution of the laminin family and contributed to the generation of lineage-specific diversity in the laminin gene complements of extant metazoans.
Article 2: “Laminins in basement membrane assembly”: The heterotrimeric laminins are a defining component of all basement membranes (BM) and self-assemble into a cell-associated network. The three short arms of the cross-shaped laminin molecule form the network nodes, with a strict requirement for one α, one β and one γ arm. The globular domain at the end of the long arm binds to cellular receptors, including integrins, α-dystroglycan, heparan sulfates and sulfated glycolipids. Collateral anchorage of the laminin network is provided by the proteoglycans perlecan and agrin. A second network is then formed by type IV collagen, which interacts with the laminin network through the heparan sulfate chains of perlecan and agrin and additional linkage by nidogen. The difficulty of imaging BMs in situ, without harmful extraction from tissues, has prevented a clearer understanding of BM architecture and our current model is largely based on a multitude of indirect clues rather than on direct observation. An intriguing aspect is that the thickness of a typical BM is of the same order as the dimensions of a single laminin molecule, which makes it unlikely that laminins are standing erect on the cell surface. Another question is whether the researchers actually know all the molecular interactions that are important for BM assembly and maturation. Some of current knowledge is based on early experiments with relatively crude protein preparations, and a search for additional interactions using modern recombinant and proteomic techniques might prove fruitful.
Article 3: "The laminin family": Laminins are large molecular weight glycoproteins constituted by the assembly of three disulfide-linked polypeptides, the α, β and γ chains. The human genome encodes 11 genetically distinct laminin chains. Structurally, laminin chains differ by the number, size and organization of a few constitutive domains, endowing the various members of the laminin family with common and unique important functions. In particular, laminins are indispensable building blocks for cellular networks physically bridging the intracellular and extracellular compartments and relaying signals critical for cellular behavior, and for extracellular polymers determining the architecture and the physiology of basement membranes. Therefore, the cell adhesion-promoting activity of laminin isoforms is now well characterized, also at the structural level. However, the specificity, if any, of the signaling pathways activated by the different laminin-binding integrins is not known.
Articule 4: "Laminin α4 deficient mice exhibit decreased capacity for adipose tissue expansion and weight gain.”: A better understanding of the mechanisms regulating adipose tissue expansion could lead to therapeutics that eliminate or reduce obesity-associated morbidity and mortality. The extracellular matrix (ECM) has been shown to regulate the development and function of numerous tissues and organs. However, there is little understanding of its function in adipose tissue. These article describes the role of laminin α4, a specialized ECM protein surrounding adipocytes, on weight gain and adipose tissue function. Adipose tissue accumulation, lipogenesis, and structure were examined in mice with a null mutation of the laminin α4 gene (Lama4-/-) and compared to wild-type (Lama4+/+) control animals. Lama4-/- mice exhibited reduced weight gain in response to both age and high fat diet. The results suggest that laminin α4 influences adipose tissue structure and function in a depot-specific manner. Alterations in laminin composition offers insight into the roll the ECM potentially plays in modulating cellular behavior in adipose tissue expansion.
Figure 1. Domain structure and self-assembly of laminin-111.
(A) Schematic drawing of the laminin-111 heterotrimer. The three short arms of the cross-shaped molecule have a common domain structure and consist of laminin N-terminal (LN) domains, laminin-type epidermal growth factor-like (LE) domains, and L4 domains, as indicated for the α1 chain. The α1 chain uniquely contains five laminin G-like (LG) domains. LG1-3 likely interact with the C-terminal residues of the γ1 chain. (B) The three-arm interaction model of laminin self-assembly. The ternary nodes in the network are formed by the N-terminal regions of one α, one β and one γ chain. The long arm of the laminin heterotrimer is not involved in network formation.
Copyright © 2012 Landes Bioscience This is an open-access article licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. The article may be redistributed, reproduced, and reused for non-commercial purposes, provided the original source is properly cited.
--Z3417843 (talk) 23:31, 5 April 2015 (EST) I just realised he did write to put it in our discussion page. I just put it in the group page because I think he meant the group project page. Anyway, for Jose (structure), I found this paper on Plos One (http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0109388) and I thought it might help you with structure. If you think it isn't that helpful, you don't have to use it :)
--Z3417843 (talk) 23:33, 5 April 2015 (EST) Also, if you're starting on working on the group project already, don't worry about tidying up the references now. It's much easier to do it later, as long as you make sure that EVERYTHING IS CITED. Thanks :)
The Heterotrimeric Laminin Coiled – Coil Domain Exerts Anti – Adhesive Effects and Induces a Pro – Invasive Phenotype
Laminins are a family of ECM glycoproteins localised in the basement membrane. As well as their structural roles, they also regulate cellular processes. These include cell migration, differentiation and proliferation. Laminins also have multiple binding partners; hence, the study was to determine what would happen to individual truncated Laminin chains in the absence of their normal partners. They did this by selecting a transfectable cell line with low endogenous Laminin chain expression, by first encoding the truncated Laminin α1, β1 and γ1 chains which encode the entire LCC. Truncated α1 chains were found to be efficiently secreted as a monomer when expressed alone, as opposed to the β1 and γ1, which were poorly secreted. But, when all three were expressed together, they formed a trimer that was secreted into the medium. This confirmed previous findings that a chain subunit expression is necessary for the secretion of the β1 and γ1 chain partners. It also confirmed consistent with previous analysis that the truncated chains can also assemble into the trimetric coiled - coil structure independent of the rest of the molecule. Through interactions with other ECM molecules and cell surface receptors, Laminins exert multiple biological functions. However, majority of the cell – binding sites map to regions distinct from the coiled – coil domain. This domain is believed to play a key role in chain assembly yet it is considered a functionally silent domain, with a few exceptions. This study first revealed and demonstrated that the Laminin coiled – coil domain inhibits cell adhesion and spreading. It is also noticed that anti – adhesive properties of ECM proteins are not a common observation. Cell adhesion modulation is often related to cell migration. The actin cytoskeleton plays an important role in the processes of cell movement, with filopodia and lamellipodia formation being crucial. Because decreased actin stress fibre formation and increased membrane ruffle formation are consistent with the promotion of cell migration, it is a tempting speculation that the adhesive property of the Laminin coiled – coil domain is linked to the modulation of cell migration in tissues where the Laminin coiled – coil domain became accessible. Reference Patricia Santos-Valle, Irene Guijarro-Muñoz, Angel M Cuesta, Vanesa Alonso-Camino, Maider Villate, Ana Alvarez-Cienfuegos, Francisco J Blanco, Laura Sanz, Luis Alvarez-Vallina The heterotrimeric laminin coiled-coil domain exerts anti-adhesive effects and induces a pro-invasive phenotype. PLoS ONE: 2012, 7(6);e39097 PMID:22723936 Copyright This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The Laminin Response in Inflammatory Bowel Disease: Protection or Malignancy?
Laminins are major components of the epithelial basement membrane. They play a crucial role in tissue homeostasis and also an important role in tissue maintenance and cancer progression, which represents an inherent risk of IBD, however this role is poorly understood. Repetitive tissue destruction, repair and oxidative damage can together trigger mutagenesis and potentially initiate cancer causing events. In wound healing and tissue repair, it is made prevalent that inflammatory responses are commonly associated with the remodelling of the ECM. Altered ECM expression and ECM binding integrin adhesion receptors have been located in several inflamed tissues. Intestinal basement membranes are specialised ECM networks that functions to separate epithelial cells from underlying connective tissue. They are mainly composed for collagen IV, Laminins, perlecan and nidogens. The basement membrane functions as a physical and chemical barrier. Several human disorders arise from defects in the BM assembly or composition. Laminin are a family of basement membrane glycoproteins. Each contains an α, β and γ chain, which form characteristic heterotrimers. Laminin, particularly the α chain that carries the cell binding domains, is important for cell adhesion, migration, proliferation and preventing cell apoptosis. Laminins have also been found in the human intestine. When there is inflammation in IBD, mucosal ulceration and subsequent tissue repairs occur, promoting the constant remodelling of the basement membrane, hence it is believed that Laminin may play an unknown role in the inflammation response, impacting the bodies response to inflammation. Furthermore, it has also been described that altered immunoreactivity of BM constituents in the IBD, have shown an increase in alpha Laminin, meaning it is likely that Laminin participates in the regeneration of the intestine. This result was highlighted when an increase in LMα1 and LMα5 expression was present in the colon tissues of IBD patients and in DSS – driven colitis in mice. The inflammation in these cases was accompanied by the nuclear accumulation of p53 as well as changes in the properties of the cell, caused in particular by the presence of the UACL in IBD. Final results revealed that the LMα1 and LMα5 chains were overexpressed, using human IBD and murine colitis specimens, when inflamed. Furthermore, results also suggested the role that Laminins could play in tissue restitution, as Laminins promoted wound closure in tissue rebuilding when there are disrupted epithelial cell monolayers. In conclusion, it was found that the forced expression of LMα1 and LMα5 protected against DDS – induced inflammation, yet in carcinogenic conditions, accelerated colitis – associated tumorigenesis. Reference Caroline Spenlé, Olivier Lefebvre, Joël Lacroute, Agnès Méchine-Neuville, Frédérick Barreau, Hervé M Blottière, Bernard Duclos, Christiane Arnold, Thomas Hussenet, Joseph Hemmerlé, Donald Gullberg, Michèle Kedinger, Lydia Sorokin, Gertraud Orend, Patricia Simon-Assmann The Laminin Response in Inflammatory Bowel Disease: Protection or Malignancy? PLoS ONE: 2014, 9(10);e111336 PMID:25347196 Copyright This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Keratinocyte – Targeted Expression of Human Laminin y2 Rescues Skin Blistering and Early Lethality of Laminin γ2 Deficient Mice
Laminin – 332 is heterotrimetric basement membrane component comprised of α3, β3 and γ2 Laminin chains. It is responsible for epithelial cell processes, including adhesion, migration and differentiation and is commonly found in many embryonic and adult tissues. Keratinocytes are responsible for the secretion of Laminin – 332 in the skin, which is identified as a key component of hemidesmosomes that connect the keratinocytes to the underlying dermis. In mice, when any of the three Laminin – 332 chains are not expressed, impaired anchorage and detachment of the epidermis occurs. This is similarly seen in human Junctional Epidermolysis Bullosa. As a result of this condition, death occurs a few days after birth. A dox – controllable human Laminin γ2 transgene was expressed, under a keratinocyte – specific promoter on the Laminin γ2 knockout background. The mice, as a result appeared similar to their wild – type littermates, didn’t develop skin blisters, were fertile and survived for more than 1.5 years. Skin is a protective barrier, composed of two primary layers, known as the epidermis and dermis. These two layers are separated a sheet of specialised extracellular matrix known at the basement membrane zone (BMZ). The BMZ functions as a border, for structural support, influences cell attachment, proliferation, differentiation and migration. Should a defect occur in the structure or in one of the components of the BMZ, tissue separation and blister formation may result. Junctional Epidermolysis Bullosa (JEB) is a genetic skin blistering disease, which results in, in the most severe cases, the death of infants within their first year of life. JEB is mostly caused by the absence of Laminin – 332, due to mutations arising within the chains. Lm -332 is secreted by skin keratinocytes and forms a critical component of the BMZ, functioning as an adhesion molecule between the epidermis and dermis. Lm – 332 is present in the basement membranes of the brain, gastrointestinal tract, heart, kidney, liver, lung, trachea, skin, spleen, thymus, salivary gland, mammary gland, ovary, prostate and testis. Hence, those who experience the skin blistering also experience blistering of the mucous membranes of the mouth and gastrointestinal tract, in turn affecting nutrition. The experiment involved the expression of the human Laminin γ2 in the mice, to test whether or not it helped prevent their early lethality. Newborn offspring that carried neither of one of the transgenes had blistered skin, smaller milk pouches and died a few days after birth. However, the mice that were carrying the human gene looked the same as the others at birth, survived for more than a year and had similar weights and lengths as the normal mice. When examining the affects of the human gene expression in the mice, the Laminin γ2 was detected in the mouth of the mice. It was also found that the newborn mice, which lacked the transgene, had a separated epidermal layer, while those who had the human Laminin showed a more attached structure. Reference Tracy L Adair-Kirk, Gail L Griffin, Michelle J Meyer, Diane G Kelley, Jeffrey H Miner, Douglas R Keene, M Peter Marinkovich, J Michael Ruppert, Jouni Uitto, Robert M Senior Keratinocyte-targeted expression of human laminin γ2 rescues skin blistering and early lethality of laminin γ2 deficient mice. PLoS ONE: 2012, 7(9);e45546 PMID:23029085 Copyright This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Laminin – 511 A multi – functional adhesion protein regulating cell migration, tumor invasion and metastasis
Laminins are major constituents of basement membranes. Recent studies indicate that Laminin – 511 contributes to tumor dissemination and metastasis in advanced breast carcinomas as well as other tumor types. Furthermore, experimental evidence has suggested that there is a prognostic significance with a higher expression of Laminin – 511 and that by targeting tumor – Laminin – 511 interactions, there may be a therapeutic potential in advanced cancer patients. Laminins are abundant extracellular matric proteins, present predominately in basement membranes. There are approximately 16 isoforms, named according to their specific combination of the α, β and γ chains. A combination of technological advances and experiments has contributed to the belief that LM – 511 and its receptors regulate cancer progression. The LM – 511 expression patterns vary between different tumor types whether it be basement membrane localisation to diffuse stromal or tumor cell expression. It’s level in tumor cells or surrounding vasculature varies based on the stage of tumor progression. Many studies show that LM – 511 expressions in advanced tumors is maintained or even increased. It’s also observed that in advanced human breast cancers and bone metastases, there is high tumor cell expression of LM – 511. Discussions are about whether future studies should look at LM – 511 expression in tumors and whether it has a particular clinical relevance with a propensity to metastasize to bone. Whether or not LM – 511 expression has any contribution to breast tumors, has not yet been fully confirmed. As has been found from previous studies, many tumor lines synthesize, secrete and adhere to LM-511, potentially indicating that LM – 511 is able to produce it’s effect on tumors via autocrine stimulation in part. Receptor studies are the reason for the many believed functions of LM’s in breast cancer progression and metastasis and it is possibly inferred, from several observations that LM – binding integrins in metastatic breast tumors are mediated through attachment to LM – 511. Laboratory results are consistent with this theory, specifically observing that metastatic breast tumor lines adhere and migrate more efficiently on LM – 511, as opposed to on metastatic lines. If the believed and found observations are correct then metastatic potential can be impacted by blocking the production of LM – 511 and or the function and expression of its receptors. Increasing experimental evidence is supporting the link of LM – 511 to cancer progression and reinforcing the belief that LM – 511 has a broad role in tumor invasion and metastasis. However, questions in regards to its prognostic significance, precise mechanism of action and potential as a therapeutic target still need to be addressed and answered. Hence, the following should be looked more into: - For staining archival material, the generation of more robust antibodies. - Clarification of the precise contribution of LM – 511 to the metastatic process. - Contribution (if any) of stromal/ vascular LM – 511 to metastasis (tumor – derived LM – 511 in metastasis is already supported). - Studies in vivo, to provide proof of the therapeutic benefits that targeting LM receptors could have. As metastasis is responsible for majority of cancer – related deaths and is a clinical challenge, the continuation of research of Laminins has the potential to present several information and solutions to overcoming this disease, as well as assist in the development of alternative strategies to prevent and/ or delay metastatic progression. Reference Normand Pouliot, Nicole Kusuma Laminin-511: a multi-functional adhesion protein regulating cell migration, tumor invasion and metastasis. Cell Adh Migr: , 7(1);142-9 PMID:23076212 Copyright This is an open-access article licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. The article may be redistributed, reproduced, and reused for non-commercial purposes, provided the original source is properly cited.
Proposed Model Figure Legend: Proposed model of LM-511 expression and function during cancer progression and metastasis. Reference: Normand Pouliot, Nicole Kusuma Laminin-511: a multi-functional adhesion protein regulating cell migration, tumor invasion and metastasis. Cell Adh Migr: , 7(1);142-9 PMID:23076212 Copyright: This is an open-access article licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. The article may be redistributed, reproduced, and reused for non-commercial purposes, provided the original source is properly cited.
Article 1: Laminin 332 or LN332 is a basally expressed extracellular matrix protein that is part of a group of laminin isoforms that demonstrates tumor-promoting properties. In normal tissue Laminin 332’s main role is to maintain epithelial-mesenchyme cohesion when the tissue is exposed to external disruptive forces. It also stimulates cells including carcinoma cells to migrate allowing for metastasis and has thus been associated with the progression of a tumor. Past research has found a direct correlation between LN331 and both Tumor invasiveness and a poor patient prognosis. The role of Laminin 332 in breast carcinomas is however unclear. This study aims to examine the relationship between Laminin 332 and breast carcinomas. The researchers tested the expression of LN332 in surgically excised breast carcinomas using immunohistochemistry (IHC) and western blot. The primary objective of the study was to examine patterns of expression in varying molecular classes of breast carcinomas. The basal-like phenotypic subgroup has a worse prognosis observed, and thus was of particular interest. The genetic profiling method that defines the basal phenotype was not widely available, so a surrogate was used, namely Triple negative (TN) breast cancer. Triple negative is a sub group of breast carcinomas that lack progesterone receptors, estrogen receptors and HER2 positivity. Results revealed 70% of TN carcinomas stained for LN332 and 14.7% of non-TN carcinomas indicating its expression with a basal phenotype. The combination of LN332 and CK 5/6 or EGFR identified 92% of triple negative breast carcinoma. Expression of the basal marker LN332 and CK 5/6 or EGFR may help in the identification of breast carcinomas with the basal phenotype. Furthermore the expression of LN332 a pro-invasive protein in TN breast carcinomas suggests another mechanism by which the TN phenotype could be aggressive. Further study will need to be performed in order to determine weather LN332 has an effect on the invasive or migratory phenotype.
Epidermolysis bullosa (EB) is a disorder resulting in structural weakening of the skin and mucous layer. Junctional EB is caused by a mutation that results in the cleavage of the dermal-epidermal junction. An unexplained phenotypic variability that is present in these mutations promotes the idea of genetic modifier effects. The study in question aims to analyze the effect of genetic modifiers on the strength of dermal-epidermal adhesion and clinical severity of Junctional EB. The results indicated that Col17a1 is a strong genetic modifier of Junctional EB that develops by mutation of Lamc2.jeb Allelic variants in Col17a1 alters the strength of dermal-epidermal adhesion therefore impacting the severity of Junctional EB. Overall the results indicated that normally innocuous allelic variants could cause mutations to have an impact on the strength of dermal-epidermal adhesion and severity of Junctional EB. This may help the genetic prognosis and diagnosis of Epidermolysis bullosa.
Article 3: Muscular dystrophy is a group of disorders characterized by the weakening of the skeletal muscle. The muscular disorders that can be caused by over 30 mutated genes, many of which encode for molecules involved in maintain structural integrity and cell adhesion. One of the most sever forms of muscular dystrophy involve the mutation of laminin α2 or LAMA2. Mutations on LAMA2 have been reported to range from absence of laminin α2 to the partial deficiency. It is however not clear as to how a laminin α2 mutation may effect protein expression and how these effected proteins cause affect disease. The aim of this study to analyze the genotype and phenotype, determine the mechanism of disease and determine the function of laminin. The study uses animal models to do this. An allelic series of mutations in the mice were used to facilitate genotype-phenotype correlation. The allelic series included mice with absence of laminin α2, reduced levels of laminin α2, truncated protein and reduced levels of truncated protein. Three lines of LAMA2 mutated mice with a complete deficiency in laminin α2 and two lines of transgenic mice with overexpressed laminin α2 were used to analyze protein expression. All the mutated mice lacked laminin α2 in peripheral nerve. The results indicate the muscular dystrophy in truncate protein mice was mild but more severe than that of the laminin α2 absent mice. The mechanisms for expression of laminin α2 in muscle and nerve also appeared different. The results provided evidence that the amount of laminin α2 is critical in the prevention of muscular dystrophy and could thus act as a possible treatment.
File:Variation in the onset and severity of JEB-nH
Thomas J Sproule, Jason A Bubier, Fiorella C Grandi, Victor Z Sun, Vivek M Philip, Caroline G McPhee, Elisabeth B Adkins, John P Sundberg, Derry C Roopenian Molecular identification of collagen 17a1 as a major genetic modifier of laminin gamma 2 mutation-induced junctional epidermolysis bullosa in mice. PLoS Genet.: 2014, 10(2);e1004068 PMID:24550734
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Epithelial-to-mesenchymal transition (EMT) is a process allowing an epithelial cell to assume a mesenchymal phenotype through biochemical changes via its basement membrane and is essential for cell migration and early embryonic development. This process is regulated by signalling pathways and cellular changes involving the expression of E-cadherin, matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9). Laminin-111, a trimeric basement membrane glycoprotein is one of the first extracellular matrix (ECM) proteins expressed during the two-cell stage in early embryogenesis and its importance together with other proteins, collagen IV, nidogen and perlecan in the assembly of the basement membrane is known. This study proposes a previously unidentified role of Laminin-111, namely its ability to influence the regulation of EMT. They report the generation of a biologically active Laminin-111 fragment by MMP2 processing and demonstrate that the fragment acts through the α3β1-integrin/extracellular matrix metalloproteinase inducer complex to trigger the down-regulation of MMP2 in human and mouse ECM. Recognizing ECM and MMP2 interactions will increase our understanding of the pluripotent stage of early embryonic development to develop new applications and disease-modeling platforms.
1.Identify an antibody that can been used in your group's extracellular matrix project.
Anti-Laminin antibody (ab11575). Function: binding to cells via a high affinity receptor, laminin is thought to mediate the attachment, migration and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components.
2.Identify the species deriving the antibody.
Rabbit polyclonal to Laminin
3.Identify the working concentration for the antibody.
Concentration batch dependent within range: 250 µl at 0.54 - 0.72 mg/ml. The referenced paper does not quote the concentration that was used.
4.Identify a secondary antibody that could be used with this antibody.
Some examples that could be used with this antibody:
Biotin-conjugated goat anti-rabbit IgG polyclonal (1/1000)
TRITC-conjugated donkey anti-rabbit IgG (H+L) polyclonal (1/200)
FITC conjugated goat anti-rabbit IgG used at a 1/100 dilution.
5.Identify a paper that has used this antibody.
Matthaei M et al. Endothelial cell microRNA expression in human late-onset Fuchs' dystrophy. Invest Ophthalmol Vis Sci 55:216-25 (2014). Human. Read more (PubMed: 24334445)
--Z3417843 (talk) 18:52, 27 April 2015 (EST) I was about to post a message asking everyone if they could post which antibody they're planning on doing but looks like everyone's done it, Hahaha! I'm still looking for antibodies for laminin. Hope you all had a great weekend!
--Z3417843 (talk) 23:48, 27 April 2015 (EST) Hey guys! I'll be doing Anti-Laminin 5 antibody (ab14509). Also,regarding historical findings for laminin, we have to find who discovered laminin, the nomenclature, and the encoding gene for laminin. I'm not too sure if we can find some of those information in research articles, specifically the person/s who discovered laminin. We will have to ask Dr Hill. Also, I did a bit of research and found out that there are several chains for laminin: 5 alpha chains (LAMA1, LAMA2, ..., LAMA5), 3 beta chains (LAMB1, LAMB2, & LAMB3), and 3 gamma chains (LAMC1, LAMC2, LAMC3). I'm still trying to wrap my head around the difference of laminin chains to laminin isoforms. I might ask Dr. Hill about it tomorrow. Hopefully those information help you find articles for laminin.
--Z3461763 (talk) 00:07, 28 April 2015 (EST) Hey hey! So I made a brief introduction summarising what we have written in the articles. It would be ideal if we could all start summarising the articles as we are suppose to slowly... You'll notice next to different points in the introduction i've written 'structure 1' or 'abnorm 2' or 'function3' or 'cr4' - the letters correspond with the section on our wiki page the article was taken from and the number indicating which article it is in order of how it has been upload - please if possible remember which article is which so that when we reference we can reference directly. Also, I copy pasted my section of antibodies... everyone do the same? Since we are presenting on Thursday, if we have the antibody information up it will be good. :) Carl, I think the history information is a good idea as well. We should have it either before structure or function or after both... because Dr Hill always includes a brief timeline of the history :)
--Z3417843 (talk) 00:17, 28 April 2015 (EST) Yeah, I was thinking we should place the 'History' section after 'Introduction' but before 'Structure'. Based on experience, it's best to leave referencing at the end, when we're tidying up. If you guys are able to do it while writing the page then great! That'll save us time editing the page.
--Z3461763 (talk) 00:21, 28 April 2015 (EST)I agree! But for now i left that as the referencing as the introduction is bound to be edited and changed as we go along - just wanted something there for this week that summarises what is on our page so far. So just keep in mind what is article 1 - 4.... but then again its posted here in discussion so no biggie :)
1) Identify an antibody that can been used in your group's transport project: Laminin α-1 Antibody (M-20)
2) Identify the species deriving the antibody: Goat polyclonal IgG
3) Identify the working concentration for the antibody: 200 µg/ml
4) Identify a secondary antibody that could be used with this antibody.
The following secondary antibodies are recommended:
1. Western Blotting: donkey anti-goat IgG-HRP: sc-2020 (dilution range: 1:2000-1:100,000) or Cruz Marker™ compatible donkey anti-goat IgG-HRP: sc-2033 (dilution range: 1:2000-1:5000), Cruz Marker™ Molecular Weight Standards: sc-2035, TBS Blotto A Blocking Reagent: sc-2333 and Western Blotting Luminal Reagent: sc-2048.
2. Immunofluorescence: donkey anti-goat IgG-FITC: sc-2024 (dilution range: 1:100- 1:400) or donkey anti-goat IgG-TR: sc-2783 (dilution range: 1:100-1:400) with UltraCruz™ Mounting Medium: sc-24941.
5) Identify a paper that has used this antibody.
--Z3417843 (talk) 23:00, 29 April 2015 (EST) Hi Rebekah! I saw this paper on pubmed (http://www.ncbi.nlm.nih.gov/pubmed/25888738) and I thought it might help contribute to your section of the project! Hope it helps!
--Z5050800 (talk) 12:32, 6 May 2015 (EST) Laminin structure clarified Laminin is a mosaic glycoprotein of the extracellular matrix (ECM) composed of different domains with different structures and functions . According to H.K. Kleinman et al. laminin has multiple structures in different tissues due to variations in the number and type of chains. Basically, the laminin structure is composed of three polypeptides chains designated A, B1 and B2 which are held together in cruciform-like structure by disulphide bonds. H.K. Kleinman et al. explains the A chain has three globular domains at the amino terminus separated by three epidermal growth factor (EGF)-like repeats. The B1 and B2 chains are structurally similar but contain only two amino terminal globules and EGF-like repeats and lack the globule at the carboxyl end . Furthermore, laminin is the major component of the basal lamina, the extracellular matrix which underlies all epithelia and surrounds muscle, peripheral nerve and fat cells. Consequently, laminin is related with cell adhesion, growth, migration, differentiation, neurite outgrowth and tumor metastases.
--Z3461763 (talk) 15:16, 6 May 2015 (EST) Jose - I'm using this article to get some brief history on laminin but there is A LOT about the structure which you can use - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3544786/ :)
Laminin is a mosaic glycoprotein of the extracellular matrix (ECM) composed of different domains with different structures and functions . According to H.K. Kleinman et al. laminin has multiple structures in different tissues due to variations in the number and type of chains. The laminin structure is composed of three polypeptides chains named A, B1 and B2 (nowadays α, β and γ chains, respectively) which are held together in cruciform-like structure by disulphide bonds. H.K. Kleinman et al. explains the A chain has three globular domains at the amino terminus separated by three epidermal growth factor (EGF)-like repeats. The B1 (or β) and B2 (or γ) chains are structurally similar but contain only two amino terminal globules and EGF-like repeats and lack the globule at the carboxyl end . Furthermore, observations indicated that the chains form an asymmetrical cross-shaped structure, with a long arm of about 77 nm carrying a large globule at its end, and three short arms, two of 34 nm and one of 48 nm, each being terminated by a globular domain .The human genome encodes 11 genetically distinct laminin chains differing at the level of the amino acid sequences. However, the polypeptide chains in a cross-shaped pattern is conserved among laminin isoforms.  Finally, laminin is the major component of the basal lamina, the extracellular matrix which surrounds all epithelia, muscle, peripheral nerve and fat cells. Consequently, laminin is related with cell adhesion, migration, growth, differentiation, neurite outgrowth and tumor metastases.
Laminin is a glycoprotein, found within the extracellular matrix , in many embryonic and adult tissues . Laminins have a cross – shaped structure, formed by three short arms, representing the alpha, beta and gama chains and one long arm which is a globular domain that binds to cellular receptors. . Laminins are the building blocks for cellular networks bridging the intracellular and extracellular compartments of the basement membranes . They regulate the development and function of numerous tissues and organs , playing an important role in tissue homeostasis and maintenance. . Laminins are also believed to play a role in cancer progression , as well as contribute to tumor dissemination and metastasis in advanced breast carcinomas as well as other tumor types . Furthermore, laminins are believed to influence adipose tissue structure , have a role in the blood – brain barrier  and also regulate cellular processes, such as cell migration, differentiation and proliferation. 
Defects in laminin chains can result in: - Ocular diseases, such as in the development of the eye  - Epidermolysis Bullosa, a disorder resulting in structural weakening of the skin and mucous layer  - Muscular dystrophy, which is a group of disorders characterised by the weakening of the skeletal muscle 
Current and potential investigations into laminin include: - The regenerative ability of human adipose tissue derived from stromal cells, which is currently being investigated in the field of regenerative medicine  - The effects on individual truncated laminin chains in the absence of their normal partner  - And possible therapeutic solutions for advanced cancer patients .
In 1979, a large, non – collagenous glycoprotein was isolated from both an Engelbreth – Holm – Swarm (EHS) sarcoma and basement membrane producing cells. Following, it was purified in quantities sufficient for biochemical, structural and immunological characterization, and given the name laminin. Through biochemical analysis, it was discovered that the laminin structure consisted of three linked polypeptides, and given the names A, B1 and B2. Electron microscopy observations revealed that these three chains formed an asymmetrical cross – shaped structure. This cross – shaped structure consisted of a long arm of approximately 77 nm, carrying a large globule at it’s end, as well as three short arms, of which two were 34 nm and one of 48 nm, all terminated by a globular domain. Furthermore it was observed that between the centre of the cross and the ends of the 34 and 48 nm short arms, one and two additional globules, respectively, were present. Through further discoveries of various cells and tissues, cloning and automated sequencing techniques, genetically different laminin subunits in humans and other species were identified. This highlighted that the laminin molecule from the EHS sarcoma was not unique, but potentially, the part of a new protein family. In order to distinguish between the diverse members, the laminins were named and number in order of their discovery. The consecutive A, B1 and B2 chains were re – named with the Greek letters, α, β, and γ, respectively. As it was noticed that the sequencing of the subunits provided evidence for distinct polypeptide sequences at the amino acid level, they were named by the addition of numbers to the Greek letters. Today, Laminin isoforms are known by their chain compositions. The α1, β1, and γ1 chain is known as laminin 111. This chain is the prototype of the laminin family and is the best characterized laminin isoform. 
Remodeling of extracellular matrix by normal and tumor-associated fibroblasts promotes cervical cancer progression 
Tumor microenvironments have become the focus of intensive research for cancer therapy. Parenchymal cells and their stromal components are separated by a basement membrane in normal epithelium. When a local host stroma is activated, the normal epithelium transitions into an invasive carcinoma. This malignant progression then prevents the normal functioning of the BM, causing the reorientation of its structure. As a result, the invasive tumor cells acquire a more metastatic phenotype, losing their epithelial characteristics. During this process, stromal cells release numerous microenvironment-influencing macromolecules, causing changes to the ECM. Fibroblasts, which play a prominent role in the pathology of solid tumors, are characteristic cell types in the microenvironment. The cancer – associated fibroblasts exhibit large quantities of ECM protein, proteases, within the reactive stroma. Matrix metalloproteinases (MMP’s) degrade the basement membrane and stromal ECM, influencing the production of malignant tumors. As a result, newly synthesized ECM proteins assist in the movement of motile tumor cells and the development of new vessels. In order to display an invasive phenotype, cervical carcinomas use the stromal MMP’s. MMP – 7 and MMP – 9 are induced into the cancer cells, made larger by tumor – stromal interactions. The stromal cells generate growth signals to the cancer cells by integrins, which are essential for the communication between cancer cells and tumorous stroma. It is this integrin communication that plays a big role in the cells survival, proliferation, migration and tumor invasion. The cytokine, TGF – β1, produced by fibroblasts is an important regulator of the ECM assembling and remodelling the ECM during cancer progression. Its known to exert a growth inhibitory action on epithelial cells, however this is lost in malignant transformation. This causes the growth factor of the ECM to convert from inhibitor to tumor promotor. This cytokine is activated through EC mechanisms such as proteases, thrombospodin – 1 and integrins. This exchange between tumor cells and fibroblasts is what influences growth factors, modifying the role they play on the tumor tissue. It was concluded that the tumor microenvironment played an influential role in the behaviour of cancer, with changes seen in the upregulation and redistribution of laminin – 1 in those cells which had undergone cancerous transformation, depositing into the BM and fibrillar connective tissue. It was also seen that there was a presence of activated myofibroblasts, which produce ECM, in the stroma. Laminin – 5 was also found to reside in the cytoplasm of cancer cells, in accordance with earlier findings. Copyright This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
--Z3417843 (talk) 16:53, 7 May 2015 (EST) hey guys! If any of you are planning on uploading a student image, you have to insert this in the summary for copyright "Copyright Beginning six months after publication, I (student number) grant the public the non-exclusive right to copy, distribute, or display the Work under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ and http://creativecommons.org/licenses/by-nc-sa/3.0/legalcode"
--Z3462921 (talk) 17:01, 14 May 2015 (EST) We should also set a date to meet up to fix the layout. Is the 28th too early or should we have it before the last lab of the semester (4th of june)? Just so we have a date to finish by.
--Z3461763 (talk) 23:55, 17 May 2015 (EST) Hey Bek, I replied earlier but the message never came up. I agree with you. I think just work on the peer review stuff up until about Saturday (including feedback etc) and then on Sunday / Monday tidy it all up.
Group 5 peer review
Informative, well referenced introduction – concise and gives a good overview into laminins. I don’t think it’s necessary to list the defects and current research here when there are sections dedicated to this near the end of the page. For the history section, it may be more eye catching if this text was split up into a timeline or flow diagram of some sort, but either way the text gives a thorough overview of the history which is good! Really good image created to highlight the structure, it’s simple and clearly explains the structure – but maybe would be good to refer to it when discussing it in the text. For this section, there is a bit too much text so maybe summarise it a bit, or maybe making both diagrams a bit smaller and wrapped around the text it’ll be sufficient to split up the big blocks of text! There are clearly lots of different laminins with different functions, therefore for this section it may be better to use a table to summarise their different functions in a concise manner, and maybe then go into detail on a few? Just below the abnormalities subheading I think it’d be good if you gave a really brief overview into the abnormalities. Well referenced information, I think it may be better if you could find some images to go with the text i.e. an image of someone with muscular dystrophy to go with the section? Some of the sections have their own reference list at the end but this would look less messy if there was just a large reference list right at the end of the project, but this is probably something you guys were planning on doing anyway! Overall, seems like you’ve got the written content sorted which is good and just need to make it a bit neater and cut down some of the large chunks of text.
Group 5 peer review
The introduction was very good, concise and succinct and it mentioned all of the important information. The way you guys have done referencing on this project is a little different to what I have seen in the other pages but I think that it is working well for you guys, but sometimes it does look a little messy? So maybe that is something you should consider. The history section might be more effective if it was done in dot point form and kept very brief. The information on the structure of laminin is quite extensive! It is a lot to get through as a reader. Maybe try to simplify some parts that are not quite as important? However, the diagram works very well in explaining the text and illustrating the structure of laminin. The functions section also looks very comprehensive and detailed and I think if you do in paragraphs it will too overwhelming and will look boring. Since you are discussing the different laminin functions, maybe tabulating what you find would be a more efficient way to discuss the function. It would be easier to read and understand for the reader. Illustrations are also lacking in this section, so definitely try and draw something or add an image if possible. The abnormalities section is good, it might again be more effective if you used some illustrations to highlight the clinical manifestations of some of these diseases. The current research section is also very very extensive, but I’m not sure it needs to be so detailed? Also the antibodies section at the end, I’m not sure if that’s supposed to be there or not. If not, I’m sure you guys will remove it. Overall, I think the project is looking very good. It just needs more illustration and the information needs to be more concise and presented in an easy to understand manner (dot points, tabulated).
Group 5 Project Review
Please don’t take this the wrong way. I’m not trying to be a jerk or put you down, just provide helpful suggestions. This page needs a lot of work. There’s a lot of content on the page, but most of it could be moved to another section, shrunk in length, or eliminated entirely. For example, why is there a brief, poorly-formatted list at the end of your introduction section? It seems completely out of place.
Let’s take the Function section as an example: why is there an exhaustive list of laminins? Could you not just give a more integrated, rounded overview of what laminin function is all about? What is their basic biochemical and cellular function? Perhaps start with something like “Laminins have diverse roles in the ECM, including smooth muscle contractility, structural support of the basement membrane, melanin synthesis…” A diagram should be used to explain this, and to break up the text a little.
There are text walls everywhere that are very hard (and extremely boring) to read on a computer screen. More visual aids are required and shorter paragraphs should be used. The actual quality of writing is good (except for where sentences are incomplete), but again, efforts should be focused on reducing the overall size of the page by making everything more concise.
Formatting needs a lot of work. You definitely, definitely need to compress your references into one, easy-to-keep-track-of section. It makes comfortable navigation of your page extremely difficult. You should also get rid of Dr Hill’s comment from 16 April. It’s cluttering your page! You need to make sure your pictures are formatted properly as well. There are copyright statements and references on the page that should be nested within the page for the image itself.
There’s a lot to be done to this page. It’s simply far too long to be comfortably readable, and is currently poorly formatted. My ultimate problem with it can be summarised with the observation that the Function section has 16 subheadings beneath it. That’s not something that the average undergraduate would be comfortable reading.
Group 5 Peer Review
I think you’ve covered an extensive amount of information in the content you’ve provided. It is very obvious that you’ve all contributed equally and exceptionally well, based on the amount of info and research.The layout of your topics and subtopic looks good it’s clear and concise. I only have a few minor suggestions and these include having only one reference list at the end of the page. I think that maybe your unsure of how to do that so here are some tips. Under your reference heading type in < references/ > (without the spaces) and all the references used will be shown under that one heading. It will add more flow to the page. Any additional referencing help can be found in the editing basics tab and then click on project referencing. I’d also suggest making your images slightly smaller because they are quite large at the moment and they sort of take over the content. Also your Copyright information should be only in the image, don’t need to have it on the page too. Another suggestion is to maybe consider some drawings, tables or collapsable tables their great for condensing info. Otherwise I think your page is pretty much set, just adjust some minor formatting things here and there and your good. I think you’ve done a brilliant job, great work everyone !! ☺
Group 5 is doing their project on Laminins. Upon the first look of their project page, it looks like it is HIGHLY disorganised. The references are separated for each section, and when I try to organise the information I'm reading, I feel like the categorising is just hard to understand. Also, the function section is just filled with a huge list of laminins, which makes me wonder if such a long list is needed, or if all of them are just as important and needed to be covered. To be honest, it is probably a better idea to take a few significant laminins and concentrate the research and article around them. Quality information is better than quantity, and maybe if you really must cover all of them, a table will help illustrate a summary of the information. Also try to break up some blocks of text into smaller paragraphs or under subheadings because it makes it easier to read, but thats just an opinion. For the diseases section, it seems like the information is categorised by papers regarding the disease. A suggestion would be to try and integrate some of the information and generalise it, because you run the risk of repeating the same information in the different papers that you cover. Some more images can be used to break up the text. Apart from all of that, it was really interesting reading about laminins. The organisation of the page could be better, but if these changes are considered their page will be much more welcoming and easier to the eye :) Good job! 
´´Group 5 Peer Review´´
Guys, your project is pretty good. You have found a lot of information. However, there should be a lot of improvements regarding organization. The great amount of information you found – or tried to find – was not well structured in the page, which leads to an incomplete understanding about laminin. For example, talking about the function of the many laminins individually gave a messy look to the page. The introduction part seems to contain information that was repeated in other sections. I think you guys should improve this section, which is one of the most relevants, in my humble opinion. Furthermore, the idea of putting the references right after each section made the page look ugly, and it also like ‘’breaks’’ the flow of the page. The structure and the history part are very good! I would not change anything in these parts, as the text is comprehensive and rich.
The abnormalities part should have more pictures, the great amount of text makes the reading tiring and hard, although the good information provided. But the biggest problem resides on the function part: what about trying to reduce the amount on ‘’laminins’’ to focus on the most relevant ones? I know you guys want to provide as much information as possible, but it can lead you to confusion sometimes.
group 5 peer review
Group 5, overall the presentation of your project seems quite messy and unorganized. Some topics are repeated along the presentation, like the function and defects/abnormalities sections and that could be cut off. The referencing below each heading breaks completely the fluidity of the project, I am sure you guys are going to fix it. The structure heading is all right, well explained and with some good pictures. However, the function topic is too long and incomplete, maybe you should just focus on the 3-5 main laminins. Abnormalities section looks pretty good, with punctual and clear information. Current research is too long, almost a third of the overall, maybe some information could be better summarised. If you focus on clarity and on simplicity this project will become a very good one.