Biotinylated carboxylases play essential roles in macronutrient metabolism. We tested the hypothesis that the abundance of biotinylated carboxylases increases in a temporal pattern during the differentiation of mesenchymal stem cells (MSC) into osteoblasts and adipocytes. Cells were collected during early (~10 d) and late stages (~20 d) of differentiation; non‐differentiating MSCs were used as control. The abundance of biotinylated pyruvate carboxylase (PC) and 3‐methylcrotonyl carboxylase (MCC) β‐chain was greater in both early and late stages of osteoblast differentiation compared with non‐differentiating controls; this was apparently caused by an (up to 180%) increase in the abundance of mRNA coding for PC and MCC during differentiation. In contrast, MSC differentiation into adipocytes was accompanied by a substantial (up to 700%) increase in the expression and biotinylation of acetyl‐CoA carboxylase 2, MCC α‐chain, and PC compared with controls, but the increased levels were limited to the early stages of differentiation. We propose that holocarboxylases play an essential role in cell differentiation and currently seek to demonstrate cause‐and‐effect by using biotin‐defined culture media and synthetic inhibitors of biotinylation events. (UNL ARD Hatch Act, NIH DK063945, DK077816, and DK082476)
Patients with end-stage renal disease (ESRD) experience disproportionately high cardiovascular morbidity and mortality. Accumulating evidence suggests a role for the circulating microbiome in the pathogenesis of cardiovascular disease; however, little is known about its association with premature cardiovascular mortality in ESRD.
It is well-known that the majority of malformations found in the human population is based on complex gene-environment interactions. As an industrial chemical sodium thiosulfate (STS) is used heavily in many industries. Nevertheless, there is little known about the effects of STS on embryo development. In the present study, we have investigated the effects of STS on cardiac development in rat cardiomyocyte H9C2 cell line and chick embryos. As determined by MTT assays, the proliferation of H9C2 cells was inhibited by STS in a dose-dependent manner. Fertilized eggs injected via the yolk sac with STS at Hamburger-Hamilton (HH) stages 6, 9 and 12 showed significantly increased cardiotoxicity at HH stage 18, including cardiomyocyte apoptosis and animal mortality. Western blot analysis showed that STS significantly affected the expression of the apoptosis-related genes bcl-2, bax, and caspase-3 in a dose-dependent manner in the H9C2 cell line and in chick embryos. Dysregulation of apoptosis was correlated with embryonic heart malformations. Thus, STS may be a potent cardiac teratogen during embryo development.