ABSTRACT: Orai1 in pancreatic ductal cells mediates pancreas-intestinal crosstalk in experimental acute pancreatitis via the secretion of antimicrobial peptide REG3B in pancreatic juice
Project description:Pancreatic ductal epithelial cells (PDECs) play a crucial role in the development of acute pancreatitis (AP). We and others have previously shown that Orai1 inhibitor confers protection against AP severity. In this study, we aim to investigate the effect and the underlying mechanisms of Orai1 in PDECs on experimental AP and its-associated intestinal damage. We found that Orai1 deletion in PDECs markedly mitigated the prolonged elevation of calcium and preserved the decreased mitochondrial membrane potential due to sodium taurocholate (NaT) or palmitoleic acid (POA) exposure. PDECs-specific Orai1 deletion notably lessened pancreatitis severity and restored the impaired pancreatic juice secretion during AP. Increased expression of tight junction proteins and decreased intestinal permeability and inflammation were observed in duodenal and colonic tissue of PDECs-specific Orai1 knockout mice. Furthermore, the deletion of Orai1 protected against pancreatitis-associated dysbiosis in the duodenum, but not in the colon. Mechanically, this protective effect was partially attributed to the enhanced secretion of REG3B in pancreatic juice during AP. Finally, intraperitoneal administration of REG3B partially alleviated AP severity and pancreatitis-associated intestinal injury and inflammation. Collectively, these findings suggest that Orai1 inhibitor may serve as potential therapeutic strategy for the management of AP and associated intestinal injury.
Project description:Background & Aims: Perturbations in pancreatic ductal bicarbonate secretion often result in chronic pancreatitis. Although the physiological mechanism of ductal secretion is known, its transcriptional control is not well characterized. Here, we investigate the role of the transcription factor Hematopoietically-expressed homeobox protein (Hhex) in pancreatic secretion and pancreatitis. Methods: We derived mice with pancreas-specific, Cre-mediated Hhex gene ablation to determine the requirement of Hhex in the pancreatic duct in early life and in adult stages. Histological and immunostaining analyses were used to detect the presence of pathology. Pancreatic primary ductal cells (PDCs) were isolated to discover differentially expressed transcripts upon acute Hhex ablation. Results: Hhex protein was detected throughout the embryonic and adult ductal trees. Ablation of Hhex in pancreatic progenitors resulted in postnatal ductal ectasia associated with acinar-to-ductal metaplasia, a progressive phenotype that ultimately resulted in chronic pancreatitis. Hhex ablation in adult mice, however, did not cause any detectable pathology. Ductal ectasia did not result from perturbations in primary cilia, but was consistent with the effects of primary ductal hypertension. RNA-seq analysis of Hhex-ablated PDCs indicated the G-protein coupled receptor Natriuretic peptide receptor 3, implicated in paracrine signaling, was upregulated 4.70-fold. Conclusions: Although Hhex is dispensable for adult pancreatic function, ablation of Hhex in pancreatic progenitors results in profound pancreatitis that is consistent with primary ductal hypertension. Our data highlight the critical role of paracrine signaling in maintaining ductal homeostasis, especially in early life, and support ductal hypersecretion as a novel etiology of pediatric chronic pancreatitis. Pancreatic primary ductal cells (PDCs) were isolated from uninduced adult HhexL/L;Sox9CreERT2 (n=2) and littermate control HhexL/L (n=2) mice. PDCs were treated with 500nM 4-hydroxytamoxifen in vitro for 4 days, and then RNA was collected for transcriptome analysis.
Project description:Background & Aims: Perturbations in pancreatic ductal bicarbonate secretion often result in chronic pancreatitis. Although the physiological mechanism of ductal secretion is known, its transcriptional control is not well characterized. Here, we investigate the role of the transcription factor Hematopoietically-expressed homeobox protein (Hhex) in pancreatic secretion and pancreatitis. Methods: We derived mice with pancreas-specific, Cre-mediated Hhex gene ablation to determine the requirement of Hhex in the pancreatic duct in early life and in adult stages. Histological and immunostaining analyses were used to detect the presence of pathology. Pancreatic primary ductal cells (PDCs) were isolated to discover differentially expressed transcripts upon acute Hhex ablation. Results: Hhex protein was detected throughout the embryonic and adult ductal trees. Ablation of Hhex in pancreatic progenitors resulted in postnatal ductal ectasia associated with acinar-to-ductal metaplasia, a progressive phenotype that ultimately resulted in chronic pancreatitis. Hhex ablation in adult mice, however, did not cause any detectable pathology. Ductal ectasia did not result from perturbations in primary cilia, but was consistent with the effects of primary ductal hypertension. RNA-seq analysis of Hhex-ablated PDCs indicated the G-protein coupled receptor Natriuretic peptide receptor 3, implicated in paracrine signaling, was upregulated 4.70-fold. Conclusions: Although Hhex is dispensable for adult pancreatic function, ablation of Hhex in pancreatic progenitors results in profound pancreatitis that is consistent with primary ductal hypertension. Our data highlight the critical role of paracrine signaling in maintaining ductal homeostasis, especially in early life, and support ductal hypersecretion as a novel etiology of pediatric chronic pancreatitis.
Project description:Cell conditioned medium from human pancreatic cancer cell lines MiaPaCa-2, AsPC-1, primary pancreatic cell lines as well as human FFPE tissue samples from pancreatic ductal adenocarcinoma (PDAC), chronic pancreatitis (CP), ampullary cancer, non-malignant adjacent pancreas and normal pancreas were analyzed via targeted (SRM, PRM) and/or explorative (DIA) mass spectrometry.
Project description:Differences in the expression profile of hepatic and pancreatic stellate cells are investigated. Aim is to identify organ and disease specific transcriptome signatures of stellate cells, comparing hepatic and pancreatic stellate cells obtained from tissues of chronic inflammation, and primary or metastatic cancers of the pancreas. Tissues of chronic pancreatitis (n=6), pancreatic ductal adenocarcinoma (n=5), liver cirrhosis (n=5) and liver metastasis of pancreatic ductal adenocarcinoma (n=6) were collected and stellate cells were isolated by the outgrowth method. Using cDNA microarrays, differentially expressed genes are identified.
Project description:Primary human pancreatic ductal organoids (HPDO) have emerged as a model to study pancreas biology and model disease like pancreatitis and pancreatic cancer. Yet, donor material availability, genetic variability and a lack of extensive benchmarking to healthy and disease pancreas limits the range of applications. To address this gap, we established porcine pancreatic ductal organoids (PPDO) as a system from a reliable, genetically defined and easily obtainable source to model pancreatic ductal/progenitor biology. We benchmarked PPDO to HPDO and primary porcine pancreas using single-cell RNA sequencing (scRNA-Seq). We observed no overt phenotypic differences in PPDO derived from distinct developmental stages using extensive proteomics profiling, with a WNT/basal cell signaling enriched population characterizing PPDO. PPDO exhibited differentiation potential towards mature ductal cells and limited potential towards endocrine lineages. We used PPDO as a chemical screening platform to assess the safety of FDA-approved drugs and showed conserved toxicity of statins and α-adrenergic receptor inhibitors between PPDO and HPDO cultures. Overall, our results highlight the PPDO as a model for mammalian duct/progenitor applications.
Project description:Pancreatic ducts form an intricate network of tubules that secrete bicarbonate and drive acinar secretions into the duodenum. This network is formed by centroacinar cells, terminal, intercalated, intracalated ducts, and the main pancreatic duct. Ductal heterogeneity at the single-cell level has been poorly characterized. Here, we used scRNA-seq to comprehensively characterize mouse ductal heterogeneity at single-cell resolution of the entire ductal epithelium from centroacinar cells to the main duct. Moreover, we used organoid cultures, injury models and pancreatic tumor samples to interrogate the role of novel ductal populations in pancreas regeneration and exocrine pathogenesis. In our study, we have identified the coexistence of 15 ductal populations within the healthy pancreas and characterized their organoid formation capacity and endocrine differentiation potential. Cluster isolation and subsequent culturing let us identify ductal cell populations with high organoid formation capacity and endocrine and exocrine differentiation potential in vitro, including Wnt-responsive-population, ciliated-population and FLRT3+ cells. Moreover, we have characterized the location of these novel ductal populations in healthy pancreas, chronic pancreatitis and tumor samples, hightlihgting a putative role of WNT-responsive, IFN-responsive and EMT-populations in pancreatic exocrine pathogenesis as their expression inceases in chronic pancreatitis and PanIN lesions. In light of our discovery of previously unidentified ductal populations, we unmask the potential roles of specific ductal populations in pancreas regeneration and exocrine pathogenesis.
Project description:Pancreatic ductal adenocarcinoma (PDA) is the devastating disease in urgent need to identify new strategies for diagnosing and treating. Chronic pancreatitis is a risk factor for PDA in humans. Nardilysin (Nrdc, NRDC), a zinc peptidase of the M16 family has been shown to promote cancer cell growth in vitro. Here, we report that pancreatic deletion of Nrdc dramatically accelerates formation of pancreatic intraepithelial neoplasia (PanIN) and invasive PDA in the presence of oncogenic Kras. Nrdc was expressed in the nucleus of pancreatic acinar cells and pancreatic deletion of Nrdc was dispensable for pancreatic development in mice, but led to spontaneous chronic pancreatitis concomitant with acinar-to-ductal conversion, fibrotic change, infiltrated inflammatory cells, increased apoptosis, and atrophic pancreas in adult mice. Ex vivo acinar cell explants culture experiments showed that acinar-to-ductal conversion was not induced through a cell autonomous mechanism and that expression of several chemokines, including Cxcl10, was markedly up-regulated in Nrdc-null pancreatic acinar cells. Microarray analysis revealed that pathways implicated in pancreatitis and tumorigenesis, including chemotaxis, NF-κB and Erk1/2 signaling, were up-regulated in Nrdc-cKO pancreata compared with WT controls. Finally, immunostaining for NRDC revealed absence of NRDC expression in a subset of human PanINs and PDAs. These data demonstrate a previously unappreciated tumor suppressive function of Nrdc in the pancreas through suppressing chronic pancreatitis with acinar-to-ductal conversion in mice.
Project description:Pancreatitis can trigger pancreatic ductal adenocarcinoma (PDAC), however, the underlying origins can be diverse and cellular and molecular mechanisms remain elusive. We show that combined genetic inactivation of the RNA-binding proteins Roquin-1 and Roquin-2 in T cells induced pancreatitis, pancreatic neoplasia and accelerated PDAC formation, if KrasG12D was expressed in acinar cells. In the pancreas, Roquin-deficient T cells were highly activated, recruited proinflammatory neutrophils via IL-17A secretion, and inappropriately produced G-CSF that, in a feed-forward loop, further induced and mobilized neutrophils. Consistently, neutralization of IL-17 or G-CSF ameliorated pancreas pathology. Roquin repressed G-CSF in two ways. It directly inhibited CSF3 mRNA expression through its 3'-UTR, and indirectly, because Roquin loss-of-function imposed transcriptional reprogramming by NF-kB and established an active enhancer at the Csf3 locus in Th17 cells. Together, we identified critical cellular and humoral components and epigenetic, transcriptional and post-transcriptional mechanisms within a regulatory circuit that prevents pancreatic cancer formation.
Project description:We used single-cell RNA sequencing to profile mouse pancreas across models of acute pancreatitis (AP), recurrent acute pancreatitis (RAP), chronic pancreatitis (CP), and oncogenic Kras-driven acute pancreatitis (K-AP, abbreviated APK). We captured both whole-pancreas cell suspensions and FACS-enriched mKate2+ epithelial populations from defined timepoints spanning early injury, recurrent damage, chronic inflammation, and Kras-driven precursor lesion formation. These data characterize acinar and epithelial plasticity and associated microenvironmental remodeling across pancreatitis and Kras-mediated disease initiation. BACKGROUND & AIMS: In response to injury, pancreatic acinar cells undergo acinar-to-ductal metaplasia (ADM), marked by loss of acinar identity and acquisition of ductal features. While ADM can resolve to support tissue repair, it may also persist and serve as a precursor to pancreatic cancer. Whether diverse pancreatic stressors drive a shared or context-specific ADM program remains unclear. We sought to comprehensively define metaplastic responses to clinically relevant exocrine pancreas diseases known to increase cancer risk. METHODS: We profiled ADM and the surrounding microenvironment across mouse models of exocrine disease—including acute, recurrent, and chronic pancreatitis, as well as in the setting of oncogenic Kras—capturing over 300,000 single cells. To enable high-quality transcriptomic profiling in enzyme-rich tissue, we leveraged FixNCut, a method that preserves RNA integrity in the exocrine pancreas. Findings were validated in human pancreas tissue using CosMx spatial transcriptomics. RESULTS: We identify a conserved acinar response across disease contexts that gives rise to previously unrecognized distinct metaplastic states, including a “gateway” ADM population that precedes more advanced metaplastic states marked by complete loss of acinar identity. In pancreatic intraepithelial neoplasia (PanIN) precancerous lesions, we detect classical-like and basal-like states, suggesting that pancreatic cancer subtypes are specified much earlier than previously appreciated. In Kras-mutant tissue, we identify a second wave of inflammation and the emergence of an immunosuppressive niche, coinciding with PanIN formation. CONCLUSIONS: Our findings define a conserved program of acinar plasticity across exocrine pancreas diseases. We further link unresolved ADM to immune remodeling during precursor lesion formation and observe the emergence of pancreatic cancer subtypes in early PanIN lesions.