Biology subjects

Capiod, T.

Publications and source records attributed to Capiod, T..

3 recordsLinked to original sources

bioRxiv2024

In vitro neuroendocrine differentiation of BPH-1 cells under beta2 adrenergic receptor stimulation

Epidemiologic and experimental animal studies have shown that stress can alter tumor growth and that adrenergic fibers from the sympathetic nervous system, acting through stromal {beta}2 adrenergic receptors, promote tumor cell survival during the initial phases of cancer development. Recent epidemiological data suggest that beta blocker intake improves survival of prostate cancer patients. Hypertension and high blood pressure have been suggested to increase likelihood of prostate cancer development, suggesting that the use of beta blockers in these patients could reduce prostate cancer risk. Signaling mediated by {beta} adrenergic receptors promotes neuroendocrine differentiation in the LNCaP prostate cancer cell line. Although neuroendocrine cells are a minor population in the epithelial compartment of normal prostate glands, the population of neuroendocrine-like cells that express markers such as SYN, Bcl-2, Dll-3, and AMACR correlates with cancer progression, androgen-independent state, and poor prognosis in prostate cancer patients. As recent studies show that an increase in neuroendocrine cell density occurs before development of benign prostatic hyperplasia, a non-lethal disease affecting the transition zone, in hypertensive rats, we investigated whether neuroendocrine differentiation is associated with benign prostatic hyperplasia. Our results showed that isobutyl-methyl-xanthine, which blocks cAMP degradation, and forskolin, an adenylate cyclase activator, triggered sustained activation of the cAMP/PKA pathway and led to an increase in neuroendocrine differentiation markers in BPH-1 cells, which are a benign prostatic hyperplasia cell line. Similar results were observed by combining the {beta} adrenergic receptors agonist isoproterenol with forskolin. The same treatments reduced BPH-1 cell proliferation rates by 40% and 60%, respectively. Effects on AMACR and SYN expression and cell proliferation were fully reversed by the {beta}2 blocker carvedilol. These data suggest that {beta} adrenergic receptors are linked to the development of neuroendocrine-like cells and benign prostatic hyperplasia. As 20% of the prostate cancer tumors occur in this zone, this observation warrants further investigation.

cancer biology↗

bioRxiv2021

Biallelic loss-of-function OBSCN variants predispose individuals to severe, recurrent rhabdomyolysis

Rhabdomyolysis is the acute breakdown of skeletal myofibres in response to an initiating factor, most commonly toxins and over exertion. A variety of genetic disorders predispose to rhabdomyolysis through different pathogenic mechanisms, particularly in patients with recurrent episodes. However, the majority of cases remain without a genetic diagnosis. Here we present six patients who presented with severe and recurrent rhabdomyolysis, usually with onset in the teenage years; other features included a history of myalgia and muscle cramps. We identified ten bi-allelic loss-of-function variants in the gene encoding obscurin (OBSCN) co-segregating with disease. We show reduced expression of OBSCN and loss of obscurin protein in patient muscle. Obscurin is proposed to be involved in SR function and Ca2+ handling. Patient cultured myoblasts appear more susceptible to starvation as evidenced by a greater decreased in SR Ca2+ content compared to control myoblasts. This likely reflects a lower efficiency when pumping Ca2+ back into the SR and/or a decrease in Ca2+ SR storage ability when metabolism is diminished. OSBCN variants have previously been associated with cardiomyopathies. None of the patients presented with a cardiomyopathy and cardiac examinations were normal in all cases in which cardiac function was assessed. There was also no history of cardiomyopathy in first degree relatives, in particular in any of the carrier parents. This cohort is relatively young, thus follow-up studies and the identification of additional cases with bi-allelic null OBSCN variants will further delineate OBSCN-related disease and the clinical course of disease.

genetics↗

bioRxiv2020

p.E152K-STIM1 mutation deregulates Ca2+ signaling contributing to chronic pancreatitis.

Since deregulation of intracellular Ca2+ can lead to intracellular trypsin activation and STIM1 (stromal interaction molecule-1) protein is the main regulator of Ca2+ homeostasis in pancreatic acinar cells, we explored the Ca2+ signaling in 37 STIM1 variants found in three pancreatitis patient cohorts. Extensive functional analysis of one particular variant, p.E152K, identified in three patients, provided a plausible link between dysregulated Ca2+ signaling within pancreatic acinar cells and chronic pancreatitis susceptibility. Specifically, p.E152K, located within the STIM1 EF-hand and sterile -motif domain, increased the release of Ca2+ from the endoplasmic reticulum in patient-derived fibroblasts and transfected HEK293T cells. This event was mediated by altered STIM1-sarco/endoplasmic reticulum calcium transport ATPase (SERCA) interactions and enhanced SERCA pump activity leading to increased Store Operated Calcium Entry (SOCE). In the pancreatic AR42J cells expressing the p.E152K variant, Ca2+-signaling perturbations correlated with defects in trypsin activation and secretion, and increased cytotoxicity after cholecystokinin stimulation. Summary statementp.E152K-STIM1 variant found in pancreatitis patients leads to intracellular changes in calcium homeostasis through SERCA interaction, enabling intracellular trypsin activation and pancreatic acinar cell death.

cell biology↗