Rabbit Anti-Human HTRA1 (a.a. 301-400) Polyclonal antibody

The goal of this study is to determine whether transforming growth factor beta 1 (Tgf-beta 1) induces the high temperature requirement A1 (HtrA1) in articular chondrocytes of two mouse models of osteoarthritis (OA). Early onset articular cartilage degeneration in the mouse models was characterized by histology. Expression profiles of Tgf-beta 1, p-Smad1, pSmad2/3 and HtrA1 in knee joints of the mouse models were examined by immunofluorescene. By in vitro and ex vivo experiments, human primary chondrocytes and articular cartilages from femoral condyles of mice were treated with recombinant human TGF-beta 1 and an ALK5 chemical inhibitor, SB431542. The level of HTRA1 mRNA in human and mouse articular chondrocytes was examined by real-time PCR. Chondrocyte clusters were present in the articular cartilage of knee joints in the mouse models. Increased expressions of Tgf-beta 1, pSmad2/3 and HtrA1 were detected in the articular chondrocyte of knee joints in the mouse models. The increased expressions of p-Smad2/3 and HtrA1 were colocalized in the articular chondrocyte of the knee joints. The expression of p-Smad1 was hardly detectable in the mouse models and their corresponding wild-type littermates. The level of HTRA1 mRNA was increased in human and mouse articular chondrocytes treated with TGF-beta 1, compared with that in chondrocytes without the treatment of TGF-beta 1. The TGF-beta 1-induced expression of HTRA1 in human and mouse articular chondrocytes was inhibited by SB431542. These results suggest that the Tgf-beta 1 canonical signaling was activated to induce HtrA1 in the articular chondrocytes of the mouse models of OA.

Age-related macular degeneration (AMD), characterized by progressive degeneration of retinal pigment epithelium (RPE), is the major cause of irreversible blindness and visual impairment in elderly population. We previously established a RPE degeneration model using an acute high dose sodium iodate to induce oxidative stress. Here we report findings on a prolonged treatment of low doses of sodium iodate on human RPE cells (ARPE-19). RPE cells were treated continuously with low doses (2-10 mM) of sodium iodate for 5 days. Low doses (2-5 mM) of sodium iodate did not reduce RPE cell viability, which is contrasting to cell apoptosis in 10 mM treatment. These low doses are sufficient to retard RPE cell migration and reduced expression of cell junction protein ZO-1. Phagocytotic activity of RPE cells was attenuated by sodium iodate dose-dependently. Sodium iodate also increased expression of FGF-2, but suppressed expression of IL-8, PDGF, TIMP-2 and VEGF. Furthermore, HTRA1 and epithelial-to-mesenchymal transition marker proteins were downregulated, whereas PERK and LC3B-II proteins were upregulated after sodium iodate treatment. These results suggested that prolonged exposure to non-lethal doses of oxidative stress induces RPE cell dysfunctions that resemble conditions in AMD. This model can be used for future drug/treatment investigation on AMD.