NIH-3T3 cells transformed by the EJ-ras oncogene display reduced platelet-derived growth factor (PDGF)-stimulated phospholipase C activity as measured by inositol 1,4,5-triphosphate (IP3) synthesis and Ca2+ mobilization. The lack of PDGF-stimulated Ca2+ mobilization in EJ-ras transformed cells is not due to a loss of IP3 sensitivity, because microinjected IP3 elevates intracellular Ca2+. Treatment of EJ-ras transformed cells with cholera toxin or 8-bromo-cyclic AMP, but not pertussis toxin or the beta-subunit of cholera toxin, results in a slight recovery of PDGF-stimulated IP3 synthesis, a marked increase in intracellular Ca2+ mobilization, and an almost complete recovery of prostaglandin E2 biosynthesis. These data suggest that EJ p21-mediated inhibition of PDGF-stimulated intracellular events can be partially and transiently reversed by cyclic AMP.
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Cell Commun Signal
January 2025
Department of Pharmacology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA.
Background: Bok is a poorly characterized Bcl-2 protein family member with roles yet to be clearly defined. It is clear, however, that Bok binds strongly to inositol 1,4,5-trisphosphate (IP) receptors (IPRs), which govern the mobilization of Ca from the endoplasmic reticulum, a signaling pathway required for many cellular processes. Also known is that Bok has a highly conserved phosphorylation site for cAMP-dependent protein kinase at serine-8 (Ser-8).
View Article and Find Full Text PDFInt Immunol
January 2025
Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
Several mesenchymal cell populations are known to regulate intestinal stem cell (ISC) self-renewal and differentiation. However, the influences of signaling mediators derived from mesenchymal cells other than ISC niche factors on epithelial homeostasis remain poorly understood. Here, we show that host and microbial metabolites, such as taurine and GABA, act on PDGFRαhigh Foxl1high sub-epithelial mesenchymal cells to regulate their transcription.
View Article and Find Full Text PDFbioRxiv
December 2024
Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, United States.
During type 1 diabetes (T1D) progression, beta cells become dysfunctional and exhibit reduced first-phase insulin release. While this period of beta cell dysfunction is well established, its cause and underlying mechanism remain unknown. To address this knowledge gap, live human pancreas tissue slices were prepared from autoantibody-negative organ donors without diabetes (ND), donors positive for one or more islet autoantibodies (AAb+), and donors with T1D within 0-4 years of diagnosis (T1D+).
View Article and Find Full Text PDFbioRxiv
December 2024
Department of Pediatrics, Child Health Research Center, University of Virginia School of Medicine, Charlottesville, Virginia.
Background: Juxtaglomerular (JG) cells are sensors that control blood pressure and fluid-electrolyte homeostasis. In response to a decrease in perfusion pressure or changes in the composition and/or volume of the extracellular fluid, JG cells release renin, which initiates an enzymatic cascade that culminates in the production of angiotensin II (Ang II), a potent vasoconstrictor that restores blood pressure and fluid homeostasis. In turn, Ang II exerts a negative feedback on renin release, thus preventing excess circulating renin and the development of hypertension.
View Article and Find Full Text PDFWater Res
January 2025
Key Laboratory of Groundwater Conservation of MWR & School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, PR China. Electronic address:
Sulfide mineral oxidation has been recognized as the key driver of arsenic (As) and antimony (Sb) mobility in mining-impacted groundwater. However, the role of carbonate and silicate weathering and secondary mineral precipitation in this process remain unknown. A comprehensive geochemical study of groundwater was conducted in an Sb-mining area, Hunan, China, with samples collected from aquifers of the Xikuangshan Formation (Dx), the Shetianqiao Formation (Ds ), and the Lower Carboniferous Formation (Cy).
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