Difference between revisions of "Talk:2015 Group 6 Project"
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Revision as of 13:15, 3 April 2015
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.
Hey, so I've just been looking around for a topic and maybe we could do something related to the fibres that make up the extracellular matrix e.g. collagen or elastin? I'm not sure though, what do you guys suggest? --Z5016650 (talk) 21:56, 22 March 2015 (EST)
- Collagen - has the most information, if we want to do this topic we have to lock it in ASAP.
- Hydrated Matrix
- Support for cells
- Pattern of ECM regulates:
- cell division
- growth factors
I think it is most likely that the topic will be broken up into structures but we may also be able to talk about the origin of EM and the function (although this may be a component of each structure that we have to discuss).
Z3333429 (talk) 00:47, 24 March 2015 (EST) I haven't heard back from Dr Hill yet. I won't be at the lecture tomorrow because I have a physio appointment so maybe ask him in the first 5 mins of the lecture just to make sure we have locked out topic in.
--Z5050795 (talk) 17:28, 26 March 2015 (EST) Hi, guys! I`m late too.. Sorry about that. The topic sounds good! My name is Laura, I`m brazilian. I`m kind of lost in everything but i really want to work and contribute with the project. I just need to understand what is going on.. Please, don`t hesitate on saying to me what you think i should listen.. =)
- 1 Function --Z5016650 (talk) 17:16, 29 March 2015 (EST)
- 2 Structure / Lab 3 Assesment --Z5050795 (talk) 22:20, 1 April 2015 (EST)
- 3 Current Research
- 4 Collagen Diseases
Collagen Type II: Function
This article suggests that the extracellular matrix of the cartilage is mainly composed of type II collagen. In healthy cartilage, type II collagen is not degraded. However, when it is degraded by enzymes this causes joint damage, this is what occurs in osteoarthritis.
In this article, it says collagen type II along with other proteins, has a role in skeletal development. Collagen II also interacts with minor collagens IX and XI to form heterotypic fibrils. Mutations in type II collagen in the extracellular matrix of the vertebrae show the important structural and developmental role of the fibrillar network.
In this article, it mentions that type II collagen is found in articular cartilage, which acts as a load bearing, low-friction, wear-resistant cushion. It is located at the ends of long bones to allow skeletal movement that is painless.
This article says that type II collagen plays an essential role in both fracture healing and long bone development. It is also mentioned that an increased production of type II collagen could enhance full bone formation. Type II collagen promotes bone marrow derived mesenchymal stem cell (BMSC) osteogenesis and inhibits adipogenesis. This means that collagen II may have a function in the early stage of BMSC differentiation.
Bone and cartilage both contain COL2A1 gene which has a role in the production of type II collagen. Therefore, mutations in such a gene can show many abnormalities.
Radiograph of the Family Members.
Collagen type II: Structure
Article One: The authors of this article were studyind the relation with cancer progression and collagen disposition in the extracellular matrix. For this, they built a 3D computational model of collagen network to study the mechanic properties of a single molecule and also fibrils and fibers. They review the tripe-helix strucutre briefly and focus on the collagen gel (collagen fibers, interconnected into a three-dimensional fiber network), measuring the distance between the cross-link interactions, the density of fibers and creating models to vary the fibers geometry and see the dinamics alterations. They found that the network geometry is a determinant key in the mechanical properties of the fiber, even more significant than the density. The stiffer and denser crosslinkers increase the mechanical stiffness of the whole network and stress can be acumulated along fibers, which is an ideia to the collagen aligment that occurs in tumor progressions.
Article two: This article links chemical properties of individual tropocollagen molecule (length) and strenght of intermolecular attractions to macroscopic mechanical response of fibril. They studied deformation in two scales to see when it changes from homogeneous intermolecular shear to propagation of slip pulses and when covalent bons within tropocollagen molecules begin to fracture and one of the conclusions is that collagen's properties are scale-dependent (the strength of an individual tropocollagen molecule is different than the strength of a collagen fiber). Although the nanoscale distribution of crosslinks give additional strenght to the fibers, extremely large crosslink densities lead to negative effects.
Article three: In this study, the authors discuss how deformation can change the microstructure at the fiber scale. For this, they simulated a stretching strain to see the evolution of both the fiber and the network and verify the presence of cell-induced aligments. At low strains, no particular aligment was observed but above some levels both fiber aligment and network density increased. In uncrosslinked networks, this aligment is found to be irreversibly imprinted, however, in crosslinked networks the similar fiber aligment and the same geometrical properties are found but with full reversibility. Strain-induced alignments were known to be a combination of reversible elastic effect and irreversible inelastic effects, but now we know that it is primarily an elastic effect.
Article four: This study uses scanning transmission electron microscopic mass mapping to develop an image of the structure of collagen fibrils from embryonic cartilage. Cartilage fibrils were harvested from 14-day-old chicken embryo sterna. These samples were then prepared for examination via electron microscopy. The results demonstrated that collagen type II in conjunction with type XI formed 10+4 microfibril structures. Evidence suggested that as long as some collagen type XI was present, over expression or mutations in collagen type II did not affect the assembly of thin fibrils. It is also apparent that microfibrils that contain XI are the nucleus for the accretions of collagen type II microfibrils.
(A) Single U87 glioblastoma cell in a collagen network 10 hours after gel polymerization. bar = 50 µm. (B) Several U87 cells on the surface of a collagen gel 10 hours after gel polymerization. bar = 200 µm. (C) Two cell colonies embedded in a collagen matrix 48 hours after gel polymerization. bar = 200 µm. Fibers (artificial red color) are imaged through confocal reflectance; cell nuclei (green) are labeled with a GFP-histone heterodimer.
Collagen gel morphological changes induced by presence of cells. 
Copyright Vader et al. 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.
- <pubmed>19529768 </pubmed>
The effect of estrogen on the expression of cartilage-specific genes in the chondrogenesis process of adipose-derived stem cells.
SUMMARY: The aim of this study was to determine the effect of estrogen on genes pertaining to chondrogenesis. Adipose-derived stem cells (ADSCs) were differentiated into cartilage and then treated with estrogen in order to determine the genetic markers associated with the expression of type II collagen.
- Cell culture: Human adipose-derived stem cells were sourced from patients aged 25-55 years using enzymatic digestion of subcutaneous tissues.
- The cells were then cultured in a modified medium that was changed two times a week allowing for differentiation into cartilaginous tissues.
- Pellet culture: Pellets of chondrogenic APSCs were formed using a centrifuge and then suspended in a treated chondrogenic medium.
- The pellets were then incubated for two weeks and the control group was left untreated whilst the experimental group was treated with estrogen E2.
- At this point in the procedure the medium was changed every three days.
- Reverse transcription polymerase chain reaction (RT-PCR): Gene expression of cartilage-specific markers was determined using the RT-PCR method.
- RNX-plus kits were used to extract the cellular RNA and any unwanted genomic DNA was removed through the use of DNase.
- Concentrations of RNA were assessed using a spectrophotometer and cDNA was synthesised from the identified RNA and used for PCR.
RESULTS and CONCLUSION: Type II collagen was found in the control group but no type II collagen was observed in the experimental group. Aggrecan was detected in both groups with a significant decrease in aggrecan expression in the experimental group.
The study demonstrated that estrogen has an inhibitory effect on the expression of type II collagen and also leads to a significant reduction in aggrecan gene expression. This means that estrogen is not suitable for use in the chondrogenesis of type II cartilage from ADSCs.
Type 1 regulatory T cells specific for collagen type II as an efficient cell-based therapy in arthritis.
SUMMARY: The aim of this study was to assess the potential of collagen type II regulatory T cells (Col-Treg) for treatment of rheumatoid arthritis (RA).
- Ethical guidelines were followed and approved of by appropriate ethic committees.
- BALB/c and DBA/1 mice were obtained and separated into transgenic groups of rearranged T-cell receptors (TCRs) and type II collagen specific T-cell hybrids.
- Col-Treg clones were generated from Col II–specific transgenic mice.
- Ova-Treg clones were generated were also generated.
- IL-10 was added to both groups on day 2 and the cells were then cloned.
- Cytokines IL-4 and interferon γ (IFN- γ) were counted using an enzyme-linked immunosorbent assay (ELISA) after two days of stimulation.
- Cytokine secretions were stained for using fluorescent dye and then analysed using fluorescence-activated cell sorting.
- The immunosuppressive function of Col-Treg clones was then assessed.
- Arthritogenic antibodies specific for collagen type II were injected intraperitoneally into 9 week old DBA/1 mice.
- Col-Treg cells were delivered via intravenous injection into the mice hours later.
- Beginning from 3 days post initial injection, the disease severity was scored using a scale:
0 = normal 1 = weak swelling 2 = significant swelling associated with redness 3 = intermediate swelling associated, or not, with redness 4 = maximal swelling and/or redness in all inflamed digits
- The number of inflamed digits were taken into account and scored appropriately (0 = no inflamed digits, 0.5 = zero to five inflamed digits, 1 = six to ten inflamed digits, 1.5 = one to fifteen inflamed digits and 2 = 16 or more inflamed digits).
- The mice were also weighed to determine any lose in body weight.
- 9-12 week old DBA/1 mice were immunised at the base of the tail with bovine type II collagen.
- 21 days after the arthritis tests, a booster shot was given.
- Col-Treg cells were injected intravenously into the mice on day 20, 22 or 28 after arthritis induction.
- The thickness of each hind paw was measured consistently after day 21 and the severity of arthritis was graded.
- Samples were collected and stained.
- Leukocyte infiltration and erosion were scored according to appropriate scales.
- Immunoglobins were measured.
- Detection of Col-Treg cells was carried out using PCR.
- 9 week old BALB/c mice were injected with ova-specific CD4 cells.
- This group was then immunised the following day with IFA.
- On day 5 one paw was injected with ovalbumin/phosphate-buffered and PBS was injected into another.
- Specific Treg cells were injected intravenously and the mice were killed after 2 days. Samples were then collected and stained.
RESULTS and CONCLUSION:
The results indicate that introduction of Col-Treg cells reduces the incidence and clinical symptoms of arthritis in both preventive and curative settings. There was a significant impact on collagen type II antibodies and there was a noticeable decrease in antigen-specific effecter T cells. These results indicate that collagen type II T regulatory cells could be an effective treatment from patients suffering from RA.
Remission of Collagen-Induced Arthritis through Combination Therapy of Microfracture and Transplantation of Thermogel-Encapsulated Bone Marrow Mesenchymal Stem Cells.
SUMMARY: This study provided a new therapeutic strategy for autoimmune inflammatory diseases such as Rheumatoid Arthritis particularly with the effect on collage type II.
- 36 male Sprague-Dawley (SD) rats were used for the experiment and ethical guidelines were followed to keep suffering minimal.
- The SD rats were divided into for groups: CON, BLA, GEL and BMC. *All groups were injected subcutaneously with collagen type II emulsion.
- Booster shots were given at d=21 with half the dose.
- All groups received operations one week after booster shots.
- In the BLA, GEL, and BMC groups a hole was drilled into the tibial plateau of the left knee and then the wound was closed.
- The CON group received a sham operation with no drilling performed. *The rats were then allowed to move freely after their respective operations and were monitored.
- Bone marrow was harvested from the tibia and femur of a 3 week old SD rat and the mononuclear cells were isolated. The bone marrow mesenchymal stem cells (BMMSCs) were prepared for use.
- The groups all received different treatments 3 days post surgery.
- BMC: PLGA-b-PEG-b-PLGA (BMMSCs); GEL: thermogel ; BLA (Blank group): phosphate-buffered saline (PBS); CON (control group): PBS
- The rats were then scored in terms of arthritis onset according to level of erythema, swelling or joint rigidity and oedema. An average of the limbs was calculated to determine scores.
- The rats were killed and both distal femurs were examined and photographed for macroscopic evaluation.
- The distal femurs were then fixed and stained in order to perform microscopic of the knee cartilage and surrounding synovium.
RESULTS and CONCLUSION: The results indicated that the majority of SD rats developed some form of irreversible bone or cartilage degradation with the exception of the BMC group. The BMC group displayed scores significantly lower than the non-treatment groups but were still possessed higher degrees of disease than normal rats. This means that BMMSC therapy can reverse synovial hyperplasia to an extent but cannot offer a full recovery.
TGF-β1 conjugated chitosan collagen hydrogels induce chondrogenic differentiation of human synovium-derived stem cells. 
SUMMARY: The purpose of this study was to test the effectiveness of a biofunctional hydrogel consisting of collagen type II nanofibers and transforming growth factor β1 (TGF-β1) in the regeneration of cartilage.
- Photocrosslinkable hydrogels were prepared.
- TGF-β1 was added to the hydrogels at a concentration of 10 μg/mL.
- Human synovium-derived mesenchymal stem cells (hSMSCs) were suspended in hydrogels and then cultured in chondrogenic medium.
- Growth of hSMSCs was observed with a light microscope.
- Cell viability was observed by staining the samples after washing with PBS and viewing them via fluorescent microscopy. Viability was determined by the ratio of live cells to total cells.
RESULTS and CONCLUSION: The results indicate that collagen type II impregnation and TGF-β1 delivery significantly promoted chondrogenesis. This hydrogel system could be an effective treatment for cartilage defects and the results support the hypothesis that collagen type II impregnation in conjunction with TGF-β1, promote chondrogenesis in hSMSCs.
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"Premature Arthritis Is a Distinct Type II Collagen Phenotype" This article is produced by the American College of Rheumatism. It's focus is on the type 2 collagen gene, COL2A1, and how mutations in this gene can result in a wide spectrum of phenotypes the affect mainly cartilage and bone. It has an extensive review that places the mutations of COL2A1, as a key marker for those patients whom have isolated degenerative joint disease. This paper gives a great foreground of type 2 collagen.
"Autoimmunity to type II collagen an experimental model of arthritis" This paper experiments with Type 2 collagen and it's results show that intradermal injection of native type II collagen, extracted from human, chick or rat cartilage) induces an inflammatory arthritis in approx 40% of rats of several strains. It shows that Type 1 and Type 3 collagen do not have the same effect.
"Ophthalmic and molecular genetic findings in Kniest dysplasia" This was a paper that studied the variability of the ophthalmic phenotype in Kniest dysplasia (inherited disorder associated with defects in type II collagen and characterised by short-trunked dwarfism, kyphoscoliosis, and enlarged joints with restricted mobility). It concludes that the ophthalmic features in Kniest dysplasia are very similar to those in other disorders of type II collagen such as Stickler syndrome. It went into great detail explaining the COL2A1 gene which will be very usual for our project.
<pubmed>12837047</pubmed> The abstract of this article eludes to the use of a denatured type 2 collagen material, UC-II, and it's success in previous studies in the reduction of joint pain and swelling for patients with Rheumatoid Arthritis and Osteoarthritis. I think this would be a good article for us to look into further. It is inaccessible, due to it not being 'FREE FULL TEXT' but if we would like we could look into it further.
Note: A lot of information was available regarding the use of denatured type 2 collagen when discussing diseases and ways to treat them. This may be a branch that my group might consider including when completing our 'Type 2 Collagen - Disease' section.
X-ray, coronal and sagittal micro-CT images1