Osteoarthritis (OA) is one of the leading joint diseases induced by abnormalities or inflammation in the synovial membrane and articular cartilage, causing severe pain and disability. Along with the cartilage malfunction, imbalanced oxygen uptake occurs, changing chondrocytes into type I collagen- and type X collagen-producing dedifferentiated cells, contributing to OA progression. However, mounting evidence suggests treating OA by inducing a hypoxic environment in the articular cartilage, targeting the inhibition of several OA-related pathways to bring chondrocytes into a normal state. This review discusses the implications of OA-diseased articular cartilage on chondrocyte phenotypes and turnover and debates the hypoxic mechanism of action. Furthermore, this review highlights the new understanding of OA, provided by tissue engineering and a regenerative medicine experimental design, modeling the disease into diverse 2D and 3D structures and investigating hypoxia and hypoxia-inducing biomolecules and potential cell therapies. This review also reports the mechanism of hypoxic regulation and highlights the importance of activating and stabilizing the hypoxia-inducible factor and related molecules to protect chondrocytes from mitochondrial dysfunction and apoptosis occurring under the influence of OA.

Coronavirus disease 2019 (COVID-19), a highly contagious viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a global health threat. The virus enters host cells by binding with angiotensin-converting enzyme 2 (ACE2), which is then facilitated by the protease activity of transmembrane serine protease 2 (TMPRSS2). It triggers a cytokine storm that eventually leads to cell apoptosis, tissue damage, and organ failure. Therefore, any organs in the human body that have both receptors are highly susceptible to COVID-19 infection, potentially resulting in multiple-organ failure. The prostate has been reported to express high levels of ACE2 and TMPRSS2. While there are limited studies regarding the association between COVID-19 and prostatitis, the possibility that SARS-CoV-2 could cause prostatitis cannot be denied. Thus, through this review, a better insight into the associations of SAR-CoV-2 can be provided.