Urine from nude mice contains epidermal growth factor (EGF) and a minor acid-stable component with an apparent molecular weight of 20,000, which competes with EGF for binding to EGF membrane receptors and which promotes colony formation by normal rat kidney cells in soft agar. The levels of this Mr 20,000 urine-derived growth factor are increased approximately 4- to 10-fold in nude mice bearing...

Transforming growth factor β1 (TGF-β1) is a polypeptide with various biological activities. Recent studies have shown that this and they receptors are expressed in human Leydig cells, Sertoli spermatogonia, spermatocytes sperm cells after birth, involved the endocrine regulation of spermatogenesis. However, there no report on expression TGF-β embryonic testis. TGF-β1 peptide widely distributed ...

Transforming growth factor-beta (TGF-beta) is an ubiquitous cytokine that affects various biological processes, such as regulation of cell proliferation, immune responses, growth, differentiation, angiogenesis, and apoptosis of various cell types. The TGF-beta ligand initiates signaling by binding to and joining type I and II receptors of serine/threonine kinases. This review discusses the TGF-...

In vertebrate embryos, maternal determinants are thought to preestablish the dorsoventral axis by locally activating zygotic ventral- and dorsal-specifying genes, e.g., genes encoding bone morphogenetic proteins (BMPs) and BMP inhibitors, respectively. Whereas the canonical Wntbeta-catenin pathway fulfills this role dorsally, the existence of a reciprocal maternal ventralizing signal remains hy...

Repair of injured renal epithelium is thought to be mediated by surviving renal proximal tubular cells (RPTC) that must dedifferentiate to allow the proliferation and migration necessary for epithelial regeneration. RPTC then redifferentiate to restore tubular structure and function. Current models suggest that epidermal growth factor receptor (EGFR) activation is required for dedifferentiation...

BACKGROUND TGF beta and its receptors are present in both germ cells and somatic cells of the male gonad. However, knock-out strategies for studying spermatogenesis regulation by TGF beta have been disappointing since TGF beta-or TGF beta receptor-null mice do not survive longer than a few weeks. METHODS In the present study, we addressed the role of TGF beta-1 on the completion of meiosis by...

Tissue patterning during development relies on cell communication by secreted proteins and receptors that engage in complex signaling crosstalk to induce distinct cell behaviors in a context-dependent fashion. Here I summarize recent insights into basic mechanisms that control the distribution and activities of transforming growth factor beta, Wnt, Hedgehog, and Notch proteins, by regulating tr...