Muscle stem (satellite) cells are relatively resistant to cell-autonomous aging. Instead, their endogenous signaling profile and regenerative capacity is strongly influenced by the aged P-Smad3, differentiated niche, and by the aged circulation. With respect to muscle fibers, we previously established that a shift from active Notch to excessive transforming growth factor-beta (TGF-beta) induces...

The two major intestinal epithelial cell lineages are columnar fluid-absorbing cells and mucin-producing goblet cells. High levels of transforming growth factor (TGF) beta1 are found surrounding postmitotic cells in the colonic crypt, suggesting that TGF-beta1 mediates the maturation and growth inhibition of both epithelial cell types. However, we now show that the injection of recombinant TGF-...

Effects of transforming growth factor beta (TGF-beta) on IgA production by LPS-stimulated B cells have been studied. TGF-beta itself could augment polyclonal IgA production in concomitant inhibition of polyclonal IgM and IgG1 production. Furthermore, TGF-beta and IL-5 additively augmented IgA production. TGF-beta exerted its activity early in the culture (by 2 d in a 5-d culture) and IL-5 was r...

In cultured vascular smooth muscle cells, the baseline mRNA and protein levels of an inducible type of nitric oxide synthase were barely detectable. Interferon gamma, tumor necrosis factor-alpha, and interleukin-1 beta each markedly increased mRNA and protein levels of this enzyme in parallel with the production of nitrite, a stable oxidative metabolite of nitric oxide. Actinomycin D abolished ...

The mechanisms for "gain-of-function" phenotypes produced by mutant p53s such as enhanced proliferation, resistance to transforming growth factor-beta-mediated growth suppression, and increased tumorigenesis are not known. One theory is that these phenotypes are caused by novel transcriptional regulatory events acquired by mutant p53s. Another explanation is that these effects are a result of a...

Sternal chondrocytes of 17-day-old chick embryos in serum-free agarose culture secrete transforming growth factor-beta. Media conditioned by such cells prevent serum-induced chondrocyte hypertrophy and cause a phenotypic modulation in serum-free culture which is similar to that observed for chondrocytes in monolayer culture. The modulated cells lose the round shape of differentiated chondrocyte...