Long-Lasting Effect of Infant Rats Endotoxemia on Heat Shock Protein 60 in the Pancreatic Acinar Cells: Involvement of Toll-Like Receptor 4

Abstract

Introduction. Lipopolysaccharide endotoxin (LPS) is responsible for septic shock and multiorgan failure, but pretreatment of rats with low doses of LPS reduced pancreatic acute damage. Aim. We investigated the effects of the endotoxemia induced in the early period of life on Toll-like receptor 4 (TLR4), heat shock protein 60 (HSP60) and proapoptotic Bax, caspase-9 and -3 or antiapoptotic Bcl-2 protein expression in the pancreatic acinar cells of adult animals. Material and Methods. Newborn rats (25 g) were injected with endotoxin (Escherichia coli) for 5 consecutive days. Two months later, pancreatic acinar cells were isolated from all groups of animals and subjected to caerulein stimulation (10−8 M). Protein expression was assessed employing Western blot. For detection of apoptosis we have employed DNA fragmentation ladder assay. Results. Preconditioning of newborn rats with LPS increased TLR4, Caspase-9 and -3 levels, but failed to affect basal expression of HSP60, Bax, and Bcl-2. Subsequent caerulein stimulation increased TLR4, Bcl-2, and caspases, but diminished HSP60 and Bax proteins in pancreatic acinar cells. Endotoxemia dose-dependently increased TLR4, Bax, HSP60, and both caspases protein signals in the pancreatic acini, further inhibiting antiapoptotic Bcl-2. Conclusions. Endotoxemia promoted the induction of HSP60 via TLR4 in the infant rats and participated in the LPS-dependent pancreatic tissue protection against acute damage.

Capsaicin-Sensitive Sensory Nerves Are Necessary for the Protective Effect of Ghrelin in Cerulein-Induced Acute Pancreatitis in Rats

“…Pancreatic acinar cells were isolated by collagenase digestion as described previously [ 112 , 113 ] and incubated in cerulein-free or cerulein containing solution. Previous studies showed that cerulein given at a concentration of 10 −8 M and 5-h incubation were most effective in stimulating exocrine secretion and gene expression in pancreatic acinar cells [ 114 , 115 ], thus these concentration of cerulein and time of incubation were selected for our current in vitro studies. Studies in each experimental group were repeated at least six times.…”

Extracellular Histones Activate Plasma Membrane Toll-Like Receptor 9 to Trigger Calcium Oscillations in Rat Pancreatic Acinar Tumor Cell AR4-2J

“…It is noteworthy that TLR4 expression was increased in pancreatic acinar cell after acute pancreatitis induced by caerulein injections or by taurocholate infusion [55,56]. LPS treatment and caerulein over-stimulation increased TLR4 content in isolated rat pancreatic acini [57]. TLR9 activation was found to stimulate pancreatic stellate cell proliferation and tumorigenesis [58,59].…”

Molecular Ghrelin System in the Pancreatic Acinar Cells: The Role of the Polypeptide, Caerulein and Sensory Nerves

“…saline or GHRL. After isolation, pancreatic acinar cells were incubated in caerulein-free or caerulein containing solution [ 126 , 127 ]. Caerulein concentration was 10 −8 M, incubation time was 5 h.…”