Journal: International Journal of Molecular Sciences

Article Title: ER Stress in ERp57 Knockout Knee Joint Chondrocytes Induces Osteoarthritic Cartilage Degradation and Osteophyte Formation

doi: 10.3390/ijms23010182

Figure Lengend Snippet: ERp57 cKO mice show an accelerated development of osteoarthritis during aging. ( A ) Histological analysis and OARSI scoring of toluidine blue-stained knee sections of 18-month-old mice reveals an increase in cartilage degradation, the occurrence of hypertrophic chondrocytes (*), and osteophyte formation (scattered box) in ERp57 cKO mice, but not in WT animals ( p = 0.0039). No significant difference was detected between younger WT and ERp57 cKO mice at the age of 9 months ( p = 0.7924) and 12 months ( p = 0.2503). Scale Bars = 100 µm. ( B ) TUNEL staining indicates a higher percentage of apoptotic cells in the articular cartilage of ERp57 cKO mice at 9 ( p = 0.0271), 12 ( p = 0.0490) and 18 months ( p = 0,000000028) compared to WT animals. Scale bars = 50 µm ( C ) Immunofluorescence of 18-month-old ERp57 cKO cartilage reveals increased staining intensities of matrix degrading proteases MMP3 ( p = 0.0004), MMP9 ( p = 0.0097), ADAMTS4 ( p = 0.0428), and ADAMTS5 ( p = 0.0288) compared to WT controls. M = months. n ≥ 4. *** p < 0.005, ** p < 0.01, * p < 0.05.

Article Snippet: Then the Vectastain ® Elite ABC Universal Kit (VEC-PK-7200, BIOZOL, Eching, Germany) and the Vector ® DAB Peroxidase Substrate (VEC-SK-4100, BIOZOL, Eching, Germany) were used according to the manufacturer’s instructions with polyclonal antibodies (anti-ADAMTS4: bs-4191R, Bioss Antibodies Inc., Woburn, MA, USA, 1:200 and ADAMTS5: bs-3573R, Bioss Antibodies Inc, Woburn, MA, USA, 1:50), which were incubated on the slides overnight at 4 °C.

Techniques: Staining, TUNEL Assay, Immunofluorescence

Journal: International Journal of Molecular Sciences

Article Title: ER Stress in ERp57 Knockout Knee Joint Chondrocytes Induces Osteoarthritic Cartilage Degradation and Osteophyte Formation

doi: 10.3390/ijms23010182

Figure Lengend Snippet: ER stress-induced osteoarthritic changes in the knee joint. Knee joints of aged ERp57 cKO animals display severe OA cartilage degeneration with enhanced MMP3, MMP9, ADAMTS4, and ADAMTS5 expression and osteophyte formation. These changes are preceded by reduced compressive stiffness of the cartilage ECM and increased apoptotic cell death. Both effects are likely induced by ER stress that cannot be adequately compensated by the UPR.

Article Snippet: Then the Vectastain ® Elite ABC Universal Kit (VEC-PK-7200, BIOZOL, Eching, Germany) and the Vector ® DAB Peroxidase Substrate (VEC-SK-4100, BIOZOL, Eching, Germany) were used according to the manufacturer’s instructions with polyclonal antibodies (anti-ADAMTS4: bs-4191R, Bioss Antibodies Inc., Woburn, MA, USA, 1:200 and ADAMTS5: bs-3573R, Bioss Antibodies Inc, Woburn, MA, USA, 1:50), which were incubated on the slides overnight at 4 °C.

Techniques: Expressing