Abstract
Simple SummaryActivated pancreatic stellate cells (aPSCs), the main source of cancer-associated fibroblasts in pancreatic ductal adenocarcinoma (PDAC), are well known as the key actor of the abundant fibrotic stroma development surrounding the tumor cells. In permanent communication with the tumor cells, they enhance PDAC early spreading and limit the drug delivery. However, the understanding of PSC activation mechanisms and the associated signaling pathways is still incomplete. In this study, we aimed to evaluate the role of Ca2+, and Orai1 Ca2+ channels, in two main PSC activation processes: cell proliferation and cytokine secretion. Indeed, Ca2+ is a versatile second messenger implicated in the regulation of numerous biological processes. We believe that a better comprehension of PSC Ca2+ -dependent activation mechanisms will bring up new crucial PDAC early prognostic markers or new targeting approaches in PDAC treatment.Activated pancreatic stellate cells (aPSCs), the crucial mediator of pancreatic desmoplasia, are characterized, among others, by high proliferative potential and abundant transforming growth factor β1 (TGFβ1) secretion. Over the past years, the involvement of Ca2+ channels in PSC pathophysiology has attracted great interest in pancreatic cancer research. We, thus, aimed to investigate the role of the Orai1 Ca2+ channel in these two PSC activation processes. Using the siRNA approach, we invalided Orai1 expression and assessed the channel functionality by Ca2+ imaging, the effect on aPSC proliferation, and TGFβ1 secretion. We demonstrated the functional expression of the Orai1 channel in human aPSCs and its implication in the store-operated Ca2+ entry (SOCE). Orai1 silencing led to a decrease in aPSC proliferation, TGFβ1 secretion, and AKT activation. Interestingly, TGFβ1 induced a higher SOCE response by increasing Orai1 mRNAs and proteins and promoted both AKT phosphorylation and cell proliferation, abolished by Orai1 silencing. Together, our results highlight the role of Orai1-mediated Ca2+ entry in human aPSC pathophysiology by controlling cell proliferation and TGFβ1 secretion through the AKT signaling pathway. Moreover, we showed a TGFβ1-induced autocrine positive feedback loop by promoting the Orai1/AKT-dependent proliferation via the stimulation of Orai1 expression and function.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.