Talk:2015 Group 6 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.
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.. =)
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>