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Cellular and Molecular Life Sciences :... Jul 2023Pancreatic cancer is typically detected at an advanced stage, and is refractory to most forms of treatment, contributing to poor survival outcomes. The incidence of... (Review)
Review
Pancreatic cancer is typically detected at an advanced stage, and is refractory to most forms of treatment, contributing to poor survival outcomes. The incidence of pancreatic cancer is gradually increasing, linked to an aging population and increasing rates of obesity and pancreatitis, which are risk factors for this cancer. Sources of risk include adipokine signaling from fat cells throughout the body, elevated levels of intrapancreatic intrapancreatic adipocytes (IPAs), inflammatory signals arising from pancreas-infiltrating immune cells and a fibrotic environment induced by recurring cycles of pancreatic obstruction and acinar cell lysis. Once cancers become established, reorganization of pancreatic tissue typically excludes IPAs from the tumor microenvironment, which instead consists of cancer cells embedded in a specialized microenvironment derived from cancer-associated fibroblasts (CAFs). While cancer cell interactions with CAFs and immune cells have been the topic of much investigation, mechanistic studies of the source and function of IPAs in the pre-cancerous niche are much less developed. Intriguingly, an extensive review of studies addressing the accumulation and activity of IPAs in the pancreas reveals that unexpectedly diverse group of factors cause replacement of acinar tissue with IPAs, particularly in the mouse models that are essential tools for research into pancreatic cancer. Genes implicated in regulation of IPA accumulation include KRAS, MYC, TGF-β, periostin, HNF1, and regulators of ductal ciliation and ER stress, among others. These findings emphasize the importance of studying pancreas-damaging factors in the pre-cancerous environment, and have significant implications for the interpretation of data from mouse models for pancreatic cancer.
Topics: Mice; Animals; Pancreatic Neoplasms; Pancreatitis; Pancreas; Acinar Cells; Carcinoma, Pancreatic Ductal; Tumor Microenvironment
PubMed: 37452870
DOI: 10.1007/s00018-023-04855-z -
Nature Communications Sep 2020Acinar metaplasia is an initial step in a series of events that can lead to pancreatic cancer. Here we perform single-cell RNA-sequencing of mouse pancreas during the...
Acinar metaplasia is an initial step in a series of events that can lead to pancreatic cancer. Here we perform single-cell RNA-sequencing of mouse pancreas during the progression from preinvasive stages to tumor formation. Using a reporter gene, we identify metaplastic cells that originated from acinar cells and express two transcription factors, Onecut2 and Foxq1. Further analyses of metaplastic acinar cell heterogeneity define six acinar metaplastic cell types and states, including stomach-specific cell types. Localization of metaplastic cell types and mixture of different metaplastic cell types in the same pre-malignant lesion is shown. Finally, single-cell transcriptome analyses of tumor-associated stromal, immune, endothelial and fibroblast cells identify signals that may support tumor development, as well as the recruitment and education of immune cells. Our findings are consistent with the early, premalignant formation of an immunosuppressive environment mediated by interactions between acinar metaplastic cells and other cells in the microenvironment.
Topics: Acinar Cells; Animals; Animals, Genetically Modified; Biopsy; Carcinoma, Pancreatic Ductal; Cell Differentiation; Disease Models, Animal; Female; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; Genetic Heterogeneity; Homeodomain Proteins; Humans; Kaplan-Meier Estimate; Male; Metaplasia; Mice; Mutation; Pancreas; Pancreatectomy; Pancreatic Neoplasms; Precancerous Conditions; Proto-Oncogene Proteins p21(ras); RNA-Seq; Single-Cell Analysis; Transcription Factors; Tumor Microenvironment
PubMed: 32908137
DOI: 10.1038/s41467-020-18207-z -
Cell Stem Cell Jun 2021The exocrine pancreas, consisting of ducts and acini, is the site of origin of pancreatitis and pancreatic ductal adenocarcinoma (PDAC). Our understanding of the genesis...
The exocrine pancreas, consisting of ducts and acini, is the site of origin of pancreatitis and pancreatic ductal adenocarcinoma (PDAC). Our understanding of the genesis and progression of human pancreatic diseases, including PDAC, is limited because of challenges in maintaining human acinar and ductal cells in culture. Here we report induction of human pluripotent stem cells toward pancreatic ductal and acinar organoids that recapitulate properties of the neonatal exocrine pancreas. Expression of the PDAC-associated oncogene GNAS induces cystic growth more effectively in ductal than acinar organoids, whereas KRAS is more effective in modeling cancer in vivo when expressed in acinar compared with ductal organoids. KRAS, but not GNAS, induces acinar-to-ductal metaplasia-like changes in culture and in vivo. We develop a renewable source of ductal and acinar organoids for modeling exocrine development and diseases and demonstrate lineage tropism and plasticity for oncogene action in the human pancreas.
Topics: Acinar Cells; Carcinoma, Pancreatic Ductal; Humans; Infant, Newborn; Oncogenes; Organoids; Pancreas; Pancreas, Exocrine; Pancreatic Neoplasms; Stem Cells
PubMed: 33915081
DOI: 10.1016/j.stem.2021.03.022 -
3D chromatin maps of the human pancreas reveal lineage-specific regulatory architecture of T2D risk.Cell Metabolism Sep 2022Three-dimensional (3D) chromatin organization maps help dissect cell-type-specific gene regulatory programs. Furthermore, 3D chromatin maps contribute to elucidating the...
Three-dimensional (3D) chromatin organization maps help dissect cell-type-specific gene regulatory programs. Furthermore, 3D chromatin maps contribute to elucidating the pathogenesis of complex genetic diseases by connecting distal regulatory regions and genetic risk variants to their respective target genes. To understand the cell-type-specific regulatory architecture of diabetes risk, we generated transcriptomic and 3D epigenomic profiles of human pancreatic acinar, alpha, and beta cells using single-cell RNA-seq, single-cell ATAC-seq, and high-resolution Hi-C of sorted cells. Comparisons of these profiles revealed differential A/B (open/closed) chromatin compartmentalization, chromatin looping, and transcriptional factor-mediated control of cell-type-specific gene regulatory programs. We identified a total of 4,750 putative causal-variant-to-target-gene pairs at 194 type 2 diabetes GWAS signals using pancreatic 3D chromatin maps. We found that the connections between candidate causal variants and their putative target effector genes are cell-type stratified and emphasize previously underappreciated roles for alpha and acinar cells in diabetes pathogenesis.
Topics: Chromatin; Diabetes Mellitus, Type 2; Gene Expression Regulation; Humans; Insulin-Secreting Cells; Islets of Langerhans
PubMed: 36070683
DOI: 10.1016/j.cmet.2022.08.014 -
JCI Insight Nov 2022Acute pancreatitis (AP) is a local and/or systemic inflammatory disease that starts with acinar cell injury and necrosis; it has no effective medical treatment and thus...
Acute pancreatitis (AP) is a local and/or systemic inflammatory disease that starts with acinar cell injury and necrosis; it has no effective medical treatment and thus remains a life-threatening condition. Interleukin-37 (IL-37), a natural immunomodulator, has demonstrated an antiinflammatory effect; however, the role of IL-37 in AP remains unknown. The serum IL-37 levels of 39 healthy controls and 94 patients with AP were measured. Cholecystokinin was applied to induce pancreatic acinar cell injury in vitro. Classical experimental AP models, such as caerulein, l-arginine, and taurolithocholic acid 3-sulfate disodium salt, were included in the in vivo study. A transgenic mouse model with the IL-37 gene and administration of recombinant IL-37 were used to further investigate the function of IL-37 in AP. Pancreas-specific gasdermin D-knockout (GSDMD-knockout) mice were used to explore the protective mechanism of IL-37. Our results showed that serum IL-37 levels in humans were negatively correlated with the severity of AP. Furthermore, IL-37-transgenic mice and supplementation with recombinant IL-37 could both protect against AP. Mechanistically, IL-37 was able to suppress pyroptosis of injured acinar cells, and specific depletion of GSDMD in the pancreas counteracted the protective effect of IL-37. Our study demonstrates that IL-37 protects against acinar cell pyroptosis in AP.
Topics: Animals; Humans; Mice; Acinar Cells; Acute Disease; Interleukins; Mice, Knockout; Mice, Transgenic; Pancreatitis; Pyroptosis
PubMed: 36166295
DOI: 10.1172/jci.insight.161244 -
Cellular and Molecular Gastroenterology... 2022Pancreatitis is characterized by acinar cell death and persistent inflammation. Ferroptosis is a type of lipid peroxidation-dependent necrosis, which is negatively...
BACKGROUND & AIMS
Pancreatitis is characterized by acinar cell death and persistent inflammation. Ferroptosis is a type of lipid peroxidation-dependent necrosis, which is negatively regulated by glutathione peroxidase 4. We studied how trypsin, a serine protease secreted by pancreatic acinar cells, affects the contribution of ferroptosis to triggering pancreatitis.
METHODS
In vitro, the mouse pancreatic acinar cell line 266-6 and mouse primary pancreatic acinar cells were used to investigate the effect of exogenous trypsin on ferroptosis sensitivity. Short hairpin RNAs were designed to silence gene expression, whereas a library of 1080 approved drugs was used to identify new ferroptosis inhibitors in 266-6 cells. In vivo, a Cre/LoxP system was used to generate mice with a pancreas-specific knockout of Gpx4 (Pdx1-Cre;Gpx4 mice). Acute or chronic pancreatitis was induced in these mice (Gpx4 mice served as controls) by cerulein injections or a Lieber-DeCarli alcoholic liquid diet. Pancreatic tissues, acinar cells, and serum were collected and analyzed by histology, immunoblot, quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, or immunohistochemical analyses.
RESULTS
Supraphysiological doses of trypsin (500 or 1000 ng/mL) alone did not trigger significant cell death in 266-6 cells and mouse primary pancreatic acinar cells, but did increase the sensitivity of these cells to ferroptosis upon treatment with cerulein, L-arginine, alcohol, erastin, or RSL3. Proteasome 26S subunit, non-adenosine triphosphatase 4-dependent lipid peroxidation caused ferroptosis in pancreatic acinar cells by promoting the proteasomal degradation of glutathione peroxidase 4. The drug screening campaign identified the antipsychotic drug olanzapine as an antioxidant inhibiting ferroptosis in pancreatic acinar cells. Mice lacking pancreatic Gpx4 developed more severe pancreatitis after cerulein infection or ethanol feeding than control mice. Conversely, olanzapine administration protected against pancreatic ferroptotic damage and experimental pancreatitis in Gpx4-deficient mice.
CONCLUSIONS
Trypsin-mediated sensitization to ferroptotic damage increases the severity of pancreatitis in mice, and this process can be reversed by olanzapine.
Topics: Animals; Ceruletide; Disease Models, Animal; Ferroptosis; Mice; Pancreatitis; Trypsin
PubMed: 34562639
DOI: 10.1016/j.jcmgh.2021.09.008 -
Science (New York, N.Y.) Sep 2021Inflammation is a major risk factor for pancreatic ductal adenocarcinoma (PDAC). When occurring in the context of pancreatitis, KRAS mutations accelerate tumor...
Inflammation is a major risk factor for pancreatic ductal adenocarcinoma (PDAC). When occurring in the context of pancreatitis, KRAS mutations accelerate tumor development in mouse models. We report that long after its complete resolution, a transient inflammatory event primes pancreatic epithelial cells to subsequent transformation by oncogenic KRAS. Upon recovery from acute inflammation, pancreatic epithelial cells display an enduring adaptive response associated with sustained transcriptional and epigenetic reprogramming. Such adaptation enables the reactivation of acinar-to-ductal metaplasia (ADM) upon subsequent inflammatory events, thereby limiting tissue damage through a rapid decrease of zymogen production. We propose that because activating mutations of KRAS maintain an irreversible ADM, they may be beneficial and under strong positive selection in the context of recurrent pancreatitis.
Topics: Acinar Cells; Animals; Carcinogenesis; Carcinoma, Pancreatic Ductal; Cell Transformation, Neoplastic; Cells, Cultured; Cellular Reprogramming; Chromatin; Early Growth Response Protein 1; Enzyme Precursors; Epigenesis, Genetic; Epithelial Cells; Female; Genes, ras; MAP Kinase Signaling System; Male; Metaplasia; Mice; Mutation; Pancreas; Pancreatitis; Spheroids, Cellular; Transcriptome
PubMed: 34529467
DOI: 10.1126/science.abj0486 -
Theranostics 2020There is no curative therapy for severe acute pancreatitis (SAP) due to poor understanding of its molecular mechanisms. Endoplasmic reticulum (ER) stress is involved in... (Observational Study)
Observational Study
There is no curative therapy for severe acute pancreatitis (SAP) due to poor understanding of its molecular mechanisms. Endoplasmic reticulum (ER) stress is involved in SAP and increased expression of ATF6 has been detected in SAP patients. Here, we aimed to investigate the role of ATF6 in a preclinical SAP mouse model and characterize its regulatory mechanism. Pancreatic tissues of healthy and SAP patients were collected during surgery. Humanized PRSS1 transgenic mice were treated with caerulein to mimic the SAP development, which was crossed to an ATF6 knockout mouse line, and pancreatic tissues from the resulting pups were screened by proteomics. Adenovirus-mediated delivery to the pancreas of SAP mice was used for shRNA-based knockdown or overexpression. The potential functions and mechanisms of ATF6 were clarified by immunofluorescence, immunoelectron microscopy, Western blotting, qRT-PCR, ChIP-qPCR and luciferase reporter assay. Increased expression of ATF6 was associated with elevated apoptosis, ER and mitochondrial disorder in pancreatic tissues from SAP patients and PRSS1 mice. Knockout of ATF6 in SAP mice attenuated acinar injury, apoptosis and ER disorder. AIFM2, known as a p53 target gene, was identified as a downstream regulatory partner of ATF6, whose expression was increased in SAP. Functionally, AIFM2 could reestablish the pathological disorder in SAP tissues in the absence of ATF6. p53 expression was also increased in SAP mice, which was downregulated by ATF6 knockout. p53 knockout significantly suppressed acinar apoptosis and injury in SAP model. Mechanistically, ATF6 promoted AIFM2 transcription by binding to p53 and AIFM2 promoters. These results reveal that ATF6/p53/AIFM2 pathway plays a critical role in acinar apoptosis during SAP progression, highlighting novel therapeutic target molecules for SAP.
Topics: Acinar Cells; Activating Transcription Factor 6; Adult; Animals; Apoptosis; Apoptosis Regulatory Proteins; Case-Control Studies; Ceruletide; Disease Models, Animal; Endoplasmic Reticulum Stress; Female; Gene Knockdown Techniques; Humans; Male; Mice, Knockout; Middle Aged; Mitochondrial Proteins; Pancreas; Pancreatitis; Transcriptional Activation; Trypsin; Tumor Suppressor Protein p53
PubMed: 32724472
DOI: 10.7150/thno.46934 -
Gastroenterology Jul 2022Mitochondrial dysfunction disrupts the synthesis and secretion of digestive enzymes in pancreatic acinar cells and plays a primary role in the etiology of exocrine...
BACKGROUND & AIMS
Mitochondrial dysfunction disrupts the synthesis and secretion of digestive enzymes in pancreatic acinar cells and plays a primary role in the etiology of exocrine pancreas disorders. However, the transcriptional mechanisms that regulate mitochondrial function to support acinar cell physiology are poorly understood. Here, we aim to elucidate the function of estrogen-related receptor γ (ERRγ) in pancreatic acinar cell mitochondrial homeostasis and energy production.
METHODS
Two models of ERRγ inhibition, GSK5182-treated wild-type mice and ERRγ conditional knock-out (cKO) mice, were established to investigate ERRγ function in the exocrine pancreas. To identify the functional role of ERRγ in pancreatic acinar cells, we performed histologic and transcriptome analysis with the pancreas isolated from ERRγ cKO mice. To determine the relevance of these findings for human disease, we analyzed transcriptome data from multiple independent human cohorts and conducted genetic association studies for ESRRG variants in 2 distinct human pancreatitis cohorts.
RESULTS
Blocking ERRγ function in mice by genetic deletion or inverse agonist treatment results in striking pancreatitis-like phenotypes accompanied by inflammation, fibrosis, and cell death. Mechanistically, loss of ERRγ in primary acini abrogates messenger RNA expression and protein levels of mitochondrial oxidative phosphorylation complex genes, resulting in defective acinar cell energetics. Mitochondrial dysfunction due to ERRγ deletion further triggers autophagy dysfunction, endoplasmic reticulum stress, and production of reactive oxygen species, ultimately leading to cell death. Interestingly, ERRγ-deficient acinar cells that escape cell death acquire ductal cell characteristics, indicating a role for ERRγ in acinar-to-ductal metaplasia. Consistent with our findings in ERRγ cKO mice, ERRγ expression was significantly reduced in patients with chronic pancreatitis compared with normal subjects. Furthermore, candidate locus region genetic association studies revealed multiple single nucleotide variants for ERRγ that are associated with chronic pancreatitis.
CONCLUSIONS
Collectively, our findings highlight an essential role for ERRγ in maintaining the transcriptional program that supports acinar cell mitochondrial function and organellar homeostasis and provide a novel molecular link between ERRγ and exocrine pancreas disorders.
Topics: Acinar Cells; Animals; Estrogens; Humans; Mice; Mice, Knockout; Pancreas; Pancreas, Exocrine; Pancreatitis, Chronic
PubMed: 35461826
DOI: 10.1053/j.gastro.2022.04.013 -
Gastroenterology Mar 2021Molecular evidence of cellular heterogeneity in the human exocrine pancreas has not been yet established because of the local concentration and cascade of hydrolytic...
BACKGROUND & AIMS
Molecular evidence of cellular heterogeneity in the human exocrine pancreas has not been yet established because of the local concentration and cascade of hydrolytic enzymes that can rapidly degrade cells and RNA upon pancreatic resection. We sought to better understand the heterogeneity and cellular composition of the pancreas in neonates and adults in healthy and diseased conditions using single-cell sequencing approaches.
METHODS
We innovated single-nucleus RNA-sequencing protocols and profiled more than 120,000 cells from pancreata of adult and neonatal human donors. We validated the single-nucleus findings using RNA fluorescence in situ hybridization, in situ sequencing, and computational approaches.
RESULTS
We created the first comprehensive atlas of human pancreas cells including epithelial and nonepithelial constituents, and uncovered 3 distinct acinar cell types, with possible implications for homeostatic and inflammatory processes of the pancreas. The comparison with neonatal single-nucleus sequencing data showed a different cellular composition of the endocrine tissue, highlighting the tissue dynamics occurring during development. By applying spatial cartography, involving cell proximity mapping through in situ sequencing, we found evidence of specific cell type neighborhoods, dynamic topographies in the endocrine and exocrine pancreas, and principles of morphologic organization of the organ. Furthermore, similar analyses in chronic pancreatitis biopsy samples showed the presence of acinar-REG cells, a reciprocal association between macrophages and activated stellate cells, and a new potential role of tuft cells in this disease.
CONCLUSIONS
Our human pancreas cell atlas can be interrogated to understand pancreatic cell biology and provides a crucial reference set for comparisons with diseased tissue samples to map the cellular foundations of pancreatic diseases.
Topics: Adolescent; Adult; Age Factors; Aged; Animals; Cell Fractionation; Cell Nucleus; Child; Child, Preschool; Female; Humans; In Situ Hybridization, Fluorescence; Infant; Male; Middle Aged; Models, Animal; Pancreas, Exocrine; RNA-Seq; Single-Cell Analysis; Swine; Young Adult
PubMed: 33212097
DOI: 10.1053/j.gastro.2020.11.010