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Cell Reports. Medicine Dec 2023Bile acids are altered and associated with prognosis in patients with acute pancreatitis (AP). Here, we conduct targeted metabolomic analyses to detect bile acids...
Bile acids are altered and associated with prognosis in patients with acute pancreatitis (AP). Here, we conduct targeted metabolomic analyses to detect bile acids changes in patients during the acute (n = 326) and the recovery (n = 133) phases of AP, as well as in healthy controls (n = 60). Chenodeoxycholic acid (CDCA) decreases in the acute phase, increases in the recovery phase, and is associated with pancreatic necrosis. CDCA and its derivative obeticholic acid exhibit a protective effect against acinar cell injury in vitro and pancreatic necrosis in murine models, and RNA sequencing reveals that the oxidative phosphorylation pathway is mainly involved. Moreover, we find that overexpression of farnesoid X receptor (FXR, CDCA receptor) inhibits pancreatic necrosis, and interfering expression of FXR exhibits an opposite phenotype in mice. Our results possibly suggest that targeting CDCA is a potential strategy for the treatment of acinar cell necrosis in AP, but further verification is needed.
Topics: Humans; Mice; Animals; Bile Acids and Salts; Pancreatitis, Acute Necrotizing; Acute Disease; Receptors, Cytoplasmic and Nuclear; Chenodeoxycholic Acid
PubMed: 38035885
DOI: 10.1016/j.xcrm.2023.101304 -
Gastroenterology Feb 2022Acinar to ductal metaplasia (ADM) occurs in the pancreas in response to tissue injury and is a potential precursor for adenocarcinoma. The goal of these studies was to...
BACKGROUND & AIMS
Acinar to ductal metaplasia (ADM) occurs in the pancreas in response to tissue injury and is a potential precursor for adenocarcinoma. The goal of these studies was to define the populations arising from ADM, the associated transcriptional changes, and markers of disease progression.
METHODS
Acinar cells were lineage-traced with enhanced yellow fluorescent protein (EYFP) to follow their fate post-injury. Transcripts of more than 13,000 EYFP+ cells were determined using single-cell RNA sequencing (scRNA-seq). Developmental trajectories were generated. Data were compared with gastric metaplasia, Kras-induced neoplasia, and human pancreatitis. Results were confirmed by immunostaining and electron microscopy. Kras was expressed in injury-induced ADM using several inducible Cre drivers. Surgical specimens of chronic pancreatitis from 15 patients were evaluated by immunostaining.
RESULTS
scRNA-seq of ADM revealed emergence of a mucin/ductal population resembling gastric pyloric metaplasia. Lineage trajectories suggest that some pyloric metaplasia cells can generate tuft and enteroendocrine cells (EECs). Comparison with Kras-induced ADM identifies populations associated with disease progression. Activation of Kras expression in HNF1B+ or POU2F3+ ADM populations leads to neoplastic transformation and formation of MUC5AC+ gastric-pit-like cells. Human pancreatitis samples also harbor pyloric metaplasia with a similar transcriptional phenotype.
CONCLUSIONS
Under conditions of chronic injury, acinar cells undergo a pyloric-type metaplasia to mucinous progenitor-like populations, which seed disparate tuft cell and EEC lineages. ADM-derived EEC subtypes are diverse. Kras expression is sufficient to drive neoplasia when targeted to injury-induced ADM populations and offers an alternative origin for tumorigenesis. This program is conserved in human pancreatitis, providing insight into early events in pancreas diseases.
Topics: Acinar Cells; Carcinoma, Pancreatic Ductal; Cell Plasticity; Enteroendocrine Cells; Gene Expression Profiling; Humans; Metaplasia; Mucin 5AC; Pancreas; Pancreatic Ducts; Pancreatic Neoplasms; Pancreatitis; Proto-Oncogene Proteins p21(ras); Single-Cell Analysis
PubMed: 34695382
DOI: 10.1053/j.gastro.2021.10.027 -
Gastroenterology Dec 2023Studies have demonstrated that activated pancreatic stellate cells (PSCs) play a crucial role in pancreatic fibrogenesis in chronic pancreatitis (CP); however, the...
Pancreatic Acinar Cells-Derived Sphingosine-1-Phosphate Contributes to Fibrosis of Chronic Pancreatitis via Inducing Autophagy and Activation of Pancreatic Stellate Cells.
BACKGROUND & AIMS
Studies have demonstrated that activated pancreatic stellate cells (PSCs) play a crucial role in pancreatic fibrogenesis in chronic pancreatitis (CP); however, the precise mechanism for PSCs activation has not been fully elucidated. We analyzed the role of injured pancreatic acinar cells (iPACs) in the activation of PSCs of CP.
METHODS
Sphingosine kinase 1 (SPHK1)/sphingosine-1-phosphate (S1P) signaling was evaluated in experimental CP induced by cerulein injection or pancreatic duct ligation, as well as in PACs injured by cholecystokinin. The activation of PSCs and pancreatic fibrosis in CP samples was evaluated by immunohistochemical and immunofluorescence analyses. In vitro coculture assay of iPACs and PSCs was created to evaluate the effect of the SPHK1/S1P pathway and S1P receptor 2 (SIPR2) on autophagy and activation of PSCs. The pathogenesis of CP was assessed in SPHK1 mice or PACs-specific SPHK1-knockdown mice with recombinant adeno-associated virus serotypes 9-SPHK1-knockdown, as well as in mice treated with inhibitor of SPHK1 and S1P receptor 2 (S1PR2).
RESULTS
SPHK1/S1P was remarkably increased in iPACs and acinar cells in pancreatic tissues of CP mice. Meanwhile, the pathogenesis, fibrosis, and PSCs activation of CP was significantly prevented in SPHK1 mice and recombinant adeno-associated virus serotypes 9-SPHK1-knockdown mice. Meanwhile, iPACs obviously activated PSCs, which was prevented by SPHK1 knockdown in iPACs. Moreover, iPACs-derived S1P specifically combined to S1PR2 of PSCs, by which modulated 5' adenosine monophosphate-activated protein kinase/mechanistic target of rapamycin pathway and consequently induced autophagy and activation of PSCs. Furthermore, hypoxia-inducible factor 1-α and -2α promoted SPHK1 transcription of PACs under hypoxia conditions, which is a distinct characteristic of the CP microenvironment. Coincidently, inhibition of SPHK1 and S1PR2 activity with inhibitor PF-543 and JTE-013 obviously impeded pancreatic fibrogenesis of CP mice.
CONCLUSIONS
The activated SPHK1/S1P pathway in iPACs induces autophagy and activation of PSCs by regulating the S1PR2/5' adenosine monophosphate-activated protein kinase/mammalian target of rapamycin pathway, which promotes fibrogenesis of CP. The hypoxia microenvironment might contribute to the cross talk between PACs and PSCs in pathogenesis of CP.
Topics: Animals; Mice; Acinar Cells; Sphingosine-1-Phosphate Receptors; Pancreatic Stellate Cells; Pancreatitis, Chronic; Autophagy; AMP-Activated Protein Kinases; Fibrosis; Adenosine Monophosphate; Hypoxia; Mammals
PubMed: 37634735
DOI: 10.1053/j.gastro.2023.08.029 -
International Journal of Molecular... Jun 2023Adult pancreatic acinar cells show high plasticity allowing them to change in their differentiation commitment. Pancreatic acinar-to-ductal metaplasia (ADM) is a... (Review)
Review
Adult pancreatic acinar cells show high plasticity allowing them to change in their differentiation commitment. Pancreatic acinar-to-ductal metaplasia (ADM) is a cellular process in which the differentiated pancreatic acinar cells transform into duct-like cells. This process can occur as a result of cellular injury or inflammation in the pancreas. While ADM is a reversible process allowing pancreatic acinar regeneration, persistent inflammation or injury can lead to the development of pancreatic intraepithelial neoplasia (PanIN), which is a common precancerous lesion that precedes pancreatic ductal adenocarcinoma (PDAC). Several factors can contribute to the development of ADM and PanIN, including environmental factors such as obesity, chronic inflammation and genetic mutations. ADM is driven by extrinsic and intrinsic signaling. Here, we review the current knowledge on the cellular and molecular biology of ADM. Understanding the cellular and molecular mechanisms underlying ADM is critical for the development of new therapeutic strategies for pancreatitis and PDAC. Identifying the intermediate states and key molecules that regulate ADM initiation, maintenance and progression may help the development of novel preventive strategies for PDAC.
Topics: Adult; Humans; Pancreatic Neoplasms; Pancreas; Carcinoma, Pancreatic Ductal; Acinar Cells; Carcinoma in Situ; Metaplasia; Inflammation
PubMed: 37373094
DOI: 10.3390/ijms24129946 -
Gut Apr 2024Epidemiological studies highlight an association between pancreatic ductal adenocarcinoma (PDAC) and oral carriage of the anaerobic bacterium , a species highly linked...
OBJECTIVE
Epidemiological studies highlight an association between pancreatic ductal adenocarcinoma (PDAC) and oral carriage of the anaerobic bacterium , a species highly linked to periodontal disease. We analysed the potential for to promote pancreatic cancer development in an animal model and probed underlying mechanisms.
DESIGN
We tracked bacterial translocation from the oral cavity to the pancreas following administration to mice. To dissect the role of in PDAC development, we administered bacteria to a genetically engineered mouse PDAC model consisting of inducible acinar cell expression of mutant ( /LSL-G12D; Ptf1a-CreER, iKC mice). These mice were used to study the cooperative effects of mutation and on the progression of pancreatic intraepithelial neoplasia (PanIN) to PDAC. The direct effects of on acinar cells and PDAC cell lines were studied in vitro.
RESULTS
migrated from the oral cavity to the pancreas in mice and can be detected in human PanIN lesions. Repetitive administration to wild-type mice induced pancreatic acinar-to-ductal metaplasia (ADM), and altered the composition of the intrapancreatic microbiome. In iKC mice, accelerated PanIN to PDAC progression. In vitro, infection induced acinar cell ADM markers SOX9 and CK19, and intracellular bacteria protected PDAC cells from reactive oxygen species-mediated cell death resulting from nutrient stress.
CONCLUSION
Taken together, our findings demonstrate a causal role for in pancreatic cancer development in mice.
Topics: Mice; Humans; Animals; Proto-Oncogene Proteins p21(ras); Base Composition; Precancerous Conditions; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Pancreatic Neoplasms; Carcinoma, Pancreatic Ductal; Carcinoma in Situ; Acinar Cells; Bacteria; Microbiota
PubMed: 38233197
DOI: 10.1136/gutjnl-2023-330941 -
Autophagy Nov 2020Pancreatitis is a common, sometimes fatal, disease of exocrine pancreas, initiated by damaged acinar cells. Recent studies implicate disordered macroautophagy/autophagy...
Pancreatitis is a common, sometimes fatal, disease of exocrine pancreas, initiated by damaged acinar cells. Recent studies implicate disordered macroautophagy/autophagy in pancreatitis pathogenesis. ATG8/LC3 protein is critical for autophagosome formation and a widely used marker of autophagic vacuoles. Transgenic GFP-LC3 mice are a valuable tool to investigate autophagy ; however, comparison of homeostatic and disease responses between GFP-LC3 and wild-type (WT) mice has not been done. We examined the effects of GFP-LC3 expression on autophagy, acinar cell function, and experimental pancreatitis. Unexpectedly, GFP-LC3 expression markedly increased endogenous LC3-II level in pancreas, caused by downregulation of ATG4B, the protease that deconjugates/delipidates LC3-II. By contrast, GFP-LC3 expression had lesser or no effect on autophagy in liver, lung and spleen. Autophagic flux analysis showed that autophagosome formation in GFP-LC3 acinar cells increased 3-fold but was not fully counterbalanced by increased autophagic degradation. Acinar cell () pancreatitis inhibited autophagic flux in WT and essentially blocked it in GFP-LC3 cells. pancreatitis caused autophagy impairment in WT mice, manifest by upregulation of LC3-II and SQSTM1/p62, increased number and size of autophagic vacuoles, and decreased level of TFEB, all of which were exacerbated in GFP-LC3 mice. GFP-LC3 expression affected key pancreatitis responses; most dramatically, it worsened increases in serum AMY (amylase), a diagnostic marker of acute pancreatitis, in several mouse models. The results emphasize physiological importance of autophagy for acinar cell function, demonstrate organ-specific effects of GFP-LC3 expression, and indicate that application of GFP-LC3 mice in disease models should be done with caution.: AP: acute pancreatitis; Arg-AP: L-arginine-induced acute pancreatitis; ATG: autophagy-related (protein); AVs: autophagic vacuoles; CCK: cholecystokinin-8; CDE: choline-deficient, D,L-ethionine supplemented diet; CER: caerulein (ortholog of CCK); CTSB: cathepsin B; CTSD: cathepsin D; CTSL: cathepsin L; ER: endoplasmic reticulum; LAMP: lysosomal-associated membrane protein; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; TEM: transmission electron microscopy; TFEB: transcription factor EB; ZG: zymogen granule(s).
Topics: Acinar Cells; Animals; Autophagosomes; Autophagy; Disease Models, Animal; Endoplasmic Reticulum; Lysosomes; Mice, Transgenic; Pancreas, Exocrine; Pancreatitis
PubMed: 31942816
DOI: 10.1080/15548627.2020.1715047 -
Cell Stem Cell Aug 2023While adult pancreatic stem cells are thought not to exist, it is now appreciated that the acinar compartment harbors progenitors, including tissue-repairing facultative...
While adult pancreatic stem cells are thought not to exist, it is now appreciated that the acinar compartment harbors progenitors, including tissue-repairing facultative progenitors (FPs). Here, we study a pancreatic acinar population marked by trefoil factor 2 (Tff2) expression. Long-term lineage tracing and single-cell RNA sequencing (scRNA-seq) analysis of Tff2-DTR-CreER-targeted cells defines a transit-amplifying progenitor (TAP) population that contributes to normal homeostasis. Following acute and chronic injury, Tff2 cells, distinct from FPs, undergo depopulation but are eventually replenished. At baseline, oncogenic Kras-targeted Tff2 cells are resistant to PDAC initiation. However, Kras activation in Tff2 cells leads to survival and clonal expansion following pancreatitis and a cancer stem/progenitor cell-like state. Selective ablation of Tff2 cells prior to Kras activation in Mist1 acinar or Dclk1 FP cells results in enhanced tumorigenesis, which can be partially rescued by adenoviral Tff2 treatment. Together, Tff2 defines a pancreatic TAP population that protects against Kras-driven carcinogenesis.
Topics: Humans; Pancreatic Neoplasms; Trefoil Factor-2; Carcinoma, Pancreatic Ductal; Pancreas; Acinar Cells; Carcinogenesis
PubMed: 37541213
DOI: 10.1016/j.stem.2023.07.002 -
Developmental Cell Dec 2023Inflammation is essential to the disruption of tissue homeostasis and can destabilize the identity of lineage-committed epithelial cells. Here, we employ lineage-traced...
Inflammation is essential to the disruption of tissue homeostasis and can destabilize the identity of lineage-committed epithelial cells. Here, we employ lineage-traced mouse models, single-cell transcriptomic and chromatin analyses, and CUT&TAG to identify an epigenetic memory of inflammatory injury in the pancreatic acinar cell compartment. Despite resolution of pancreatitis, our data show that acinar cells fail to return to their molecular baseline, with retention of elevated chromatin accessibility and H3K4me1 at metaplasia genes, such that memory represents an incomplete cell fate decision. In vivo, we find this epigenetic memory controls lineage plasticity, with diminished metaplasia in response to a second insult but increased tumorigenesis with an oncogenic Kras mutation. The lowered threshold for oncogenic transformation, in turn, can be restored by blockade of MAPK signaling. Together, we define the chromatin dynamics, molecular encoding, and recall of a prolonged epigenetic memory of inflammatory injury that impacts future responses but remains reversible.
Topics: Mice; Animals; Pancreatic Neoplasms; Epigenetic Memory; Cell Transformation, Neoplastic; Acinar Cells; Pancreas; Chromatin; Metaplasia; Carcinoma, Pancreatic Ductal
PubMed: 38056453
DOI: 10.1016/j.devcel.2023.11.008 -
Nature Sep 2021Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer deaths worldwide. Studies in human tissues and in mouse models have suggested that for...
Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer deaths worldwide. Studies in human tissues and in mouse models have suggested that for many cancers, stem cells sustain early mutations driving tumour development. For the pancreas, however, mechanisms underlying cellular renewal and initiation of PDAC remain unresolved. Here, using lineage tracing from the endogenous telomerase reverse transcriptase (Tert) locus, we identify a rare TERT-positive subpopulation of pancreatic acinar cells dispersed throughout the exocrine compartment. During homeostasis, these TERT acinar cells renew the pancreas by forming expanding clones of acinar cells, whereas randomly marked acinar cells do not form these clones. Specific expression of mutant Kras in TERT acinar cells accelerates acinar clone formation and causes transdifferentiation to ductal pre-invasive pancreatic intraepithelial neoplasms by upregulating Ras-MAPK signalling and activating the downstream kinase ERK (phospho-ERK). In resected human pancreatic neoplasms, we find that foci of phospho-ERK-positive acinar cells are common and frequently contain activating KRAS mutations, suggesting that these acinar regions represent an early cancer precursor lesion. These data support a model in which rare TERT acinar cells may sustain KRAS mutations, driving acinar cell expansion and creating a field of aberrant cells initiating pancreatic tumorigenesis.
Topics: Acinar Cells; Animals; Carcinogenesis; Carcinoma, Pancreatic Ductal; Cell Transdifferentiation; Cell Transformation, Neoplastic; Homeostasis; Humans; MAP Kinase Signaling System; Mice; Mutation; Pancreas; Pancreatic Neoplasms; Proto-Oncogene Proteins p21(ras); Telomerase
PubMed: 34526722
DOI: 10.1038/s41586-021-03916-2 -
Gastroenterology Jun 2024Acinar cells produce digestive enzymes that impede transcriptomic characterization of the exocrine pancreas. Thus, single-cell RNA-sequencing studies of the pancreas...
BACKGROUND & AIMS
Acinar cells produce digestive enzymes that impede transcriptomic characterization of the exocrine pancreas. Thus, single-cell RNA-sequencing studies of the pancreas underrepresent acinar cells relative to histological expectations, and a robust approach to capture pancreatic cell responses in disease states is needed. We sought to innovate a method that overcomes these challenges to accelerate study of the pancreas in health and disease.
METHODS
We leverage FixNCut, a single-cell RNA-sequencing approach in which tissue is reversibly fixed with dithiobis(succinimidyl propionate) before dissociation and single-cell preparation. We apply FixNCut to an established mouse model of acute pancreatitis, validate findings using GeoMx whole transcriptome atlas profiling, and integrate our data with prior studies to compare our method in both mouse and human pancreas datasets.
RESULTS
FixNCut achieves unprecedented definition of challenging pancreatic cells, including acinar and immune populations in homeostasis and acute pancreatitis, and identifies changes in all major cell types during injury and recovery. We define the acinar transcriptome during homeostasis and acinar-to-ductal metaplasia and establish a unique gene set to measure deviation from normal acinar identity. We characterize pancreatic immune cells, and analysis of T-cell subsets reveals a polarization of the homeostatic pancreas toward type-2 immunity. We report immune responses during acute pancreatitis and recovery, including early neutrophil infiltration, expansion of dendritic cell subsets, and a substantial shift in the transcriptome of macrophages due to both resident macrophage activation and monocyte infiltration.
CONCLUSIONS
FixNCut preserves pancreatic transcriptomes to uncover novel cell states during homeostasis and following pancreatitis, establishing a broadly applicable approach and reference atlas for study of pancreas biology and disease.
Topics: Animals; Pancreatitis; Homeostasis; Transcriptome; Single-Cell Analysis; Humans; Acinar Cells; Mice; Disease Models, Animal; Pancreas; Gene Expression Profiling; RNA-Seq; Acute Disease; Pancreas, Exocrine; Macrophages; Metaplasia; Mice, Inbred C57BL
PubMed: 38325760
DOI: 10.1053/j.gastro.2024.01.043