De-ubiquitinating enzymes: intracellular signalling and disease

circCD2AP promotes epithelial mesenchymal transition and stemness in bladder cancer by regulating FOXQ1/USP21 axis

Bladder cancer (BC) is a prevalent and deadly disease. circCD2AP was suggested to be highly expressed in BC. However, the exact mechanism needs further investigation. In this study, circCD2AP was observed to be upregulated in BC and linked to poor prognosis in individuals. Functionally, circCD2AP or USP21 knockdown inhibited BC cell EMT and stemness both in vitro and in vivo. Mechanistically, circCD2AP interacted with ELAVL1 to enhance the stability of USP21 mRNA, which, in turn, inhibited the ubiquitination degradation of FOXQ1. Through rescue assay, USP21 or FOXQ1 knockdown was found to abolish the promoting effects of circCD2AP or USP21 overexpression on BC cell EMT and stemness. Overall, this study has unveiled the role of circCD2AP/ELAVL1/USP21/FOXQ1 axis in BC EMT and stemness regulation, offering insights into the mechanisms underlying BC progression, with potential implications for therapeutic strategies.

The Combinatorial Nature of Osmosensing in Fishes

Organisms exposed to altered salinity must be able to perceive osmolality change because metabolism has evolved to function optimally at specific intracellular ionic strength and composition. Such osmosensing comprises a complex physiological process involving many elements at organismal and cellular levels of organization. Input from numerous osmosensors is integrated to encode magnitude, direction, and ionic basis of osmolality change. This combinatorial nature of osmosensing is discussed with emphasis on fishes.

Functional analysis of the porcine USP18 and its role during porcine arterivirus replication

Emerging evidence places deubiquitylation at the core of a multitude of regulatory processes, ranging from cell growth to innate immune response and health, such as cancer, degenerative and infectious diseases. Little is known about deubiquitylation in pig and arterivirus infection. This report provides information on the biochemical and functional role of the porcine USP18 during innate immune response to the porcine respiratory and reproductive syndrome virus (PRRSV). We have shown that UBP gene is the ortholog of the murine USP18 (Ubp43) gene and the human ubiquitin specific protease 18 (USP18) gene and encodes a biochemically functional de-ubiquitin enzyme which inhibits signalling pathways that lead to IFN-stimulating response element (ISRE) promotor regulation. Furthermore we have demonstrated that overexpression of the porcine USP18 leads to reduced replication and/or growth of PRRSV. Our data contrast with the conclusion of numerous reports demonstrating that USP18-deficient mice are highly resistant to viral and bacterial infections and to oncogenic transformation by BCR-ABL, and highlight USP18 as a potential target gene that promotes reduced replication of PRRSV.

Roles of NF-kappaB in health and disease: mechanisms and therapeutic potential

The NF-kappaB (nuclear factor kappaB) family of transcription factors are involved in a myriad of activities, including the regulation of immune responses, maturation of immune cells, development of secondary lymphoid organs and osteoclastogenesis. Fine tuning by positive and negative regulators keeps the NF-kappaB signalling pathway in check. Microbial products and genetic alterations in NF-kappaB and other signalling pathway components can lead to deregulation of NF-kappaB signalling in several human diseases, including cancers and chronic inflammatory disorders. NF-kappaB-pathway-specific therapies are being actively investigated, and these hold promises as interventions of NF-kappaB-related ailments.