0000000001090821
AUTHOR
Maylin Almonte-becerril
Changes in the integrins expression are related with the osteoarthritis severity in an experimental animal model in rats
We identify changes in the expression and localization of α5, α4, and α2 integrins during osteoarthritis (OA) pathogenesis in a rat experimental model. The changes were concomitant with variations in the extracellular matrix (ECM) content and the increase of metalloproteinases (MMPs) activity during OA pathogenesis, which were analyzed by immunofluorescence and Western blot assays. Our results showed an increased expression of α5 and α2 integrins at OA late stages, which was co-related with changes in the ECM content, as a consequence of the MMPs activity. In addition, this is the first report that has shown the presence of α4 integrin since OA early stages, which was co-related with the lo…
Genetic abrogation of the fibronectin-α5β1 integrin interaction in articular cartilage aggravates osteoarthritis in mice.
The balance between synthesis and degradation of the cartilage extracellular matrix is severely altered in osteoarthritis, where degradation predominates. One reason for this imbalance is believed to be due to the ligation of the α5β1 integrin, the classic fibronectin (FN) receptor, with soluble FN fragments instead of insoluble FN fibrils, which induces matrix metalloproteinase (MMP) expression. Our objective was to determine whether the lack of α5β1-FN binding influences cartilage morphogenesis in vivo and whether non-ligated α5β1 protects or aggravates the course of osteoarthritis in mice. We engineered mice (Col2a-Cre;Fn1RGE/fl), whose chondrocytes express an α5β1 binding-deficient FN, …
Autophagy
Klionsky, Daniel J. et al.
Perlecan Maintains microvessel integrity in vivo and modulates their formation in vitro
Perlecan is a heparan sulfate proteoglycan assembled into the vascular basement membranes (BMs) during vasculogenesis. In the present study we have investigated vessel formation in mice, teratomas and embryoid bodies (EBs) in the absence of perlecan. We found that perlecan was dispensable for blood vessel formation and maturation until embryonic day (E) 12.5. At later stages of development 40% of mutant embryos showed dilated microvessels in brain and skin, which ruptured and led to severe bleedings. Surprisingly, teratomas derived from perlecan-null ES cells showed efficient contribution of perlecan-deficient endothelial cells to an apparently normal tumor vasculature. However, in perlecan…