Xylosyltransferase gene variants and their role in essential hypertension

An insertion-deletion polymorphism in angiotensin-converting enzyme is associated with a reduced risk of preeclampsia: an evidence-based meta-analysis from 44 studies

Objective An updated meta-analysis was performed to evaluate the relationship between an insertion/deletion (I/D) polymorphism in angiotensin-converting enzyme (ACE) and preeclampsia (PE) risk. Methods Pubmed, OVID and China National Knowledge Infrastructure databases were searched. Pooled odds ratios with 95% confidence intervals were calculated using fixed-effects or random-effects model. Results ACE I/D polymorphism decreased the risk of PE in overall analysis. Subgroup analysis revealed a significantly lower risk of PE with ACE I/D polymorphism in Asians, Caucasians. The decreased risk was also found in severe PE and early-onset PE. Conclusion ACE I/D polymorphism may protect against the development of PE.

Activin A-Mediated Regulation of XT-I in Human Skin Fibroblasts

Fibrosis is a fundamental feature of systemic sclerosis (SSc) and is characterized by excessive accumulation of extracellular matrix components like proteoglycans (PG) or collagens in skin and internal organs. Serum analysis from SSc patients showed an increase in the enzyme activity of xylosyltransferase (XT), the initial enzyme in PG biosynthesis. There are two distinct XT isoforms-XT-I and XT-II-in humans, but until now only XT-I is associated with fibrotic remodelling for an unknown reason. The aim of this study was to identify new XT mediators and clarify the underlying mechanisms, in view of developing putative therapeutic anti-fibrotic interventions in the future. Therefore, we used different cytokines and growth factors, small molecule inhibitors as well as small interfering RNAs, and assessed the cellular XT activity and XYLT1 expression in primary human dermal fibroblasts by radiochemical activity assays and qRT-PCR. We identified a new function of activin A as a regulator of XYLT1 mRNA expression and XT activity. While the activin A-induced XT-I increase was found to be mediated by activin A receptor type 1B, MAPK and Smad pathways, the activin A treatment did not alter the XYLT2 expression. Furthermore, we observed a reciprocal regulation of XYLT1 and XYLT2 transcription after inhibition of the activin A pathway components. These results improve the understanding of the differential expression regulation of XYLT isoforms under pathological fibroproliferative conditions.