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Gastroenterology May 2024Acinar-to-ductal metaplasia (ADM) is crucial in the development of pancreatic ductal adenocarcinoma. However, our understanding of the induction and resolution of ADM...
BACKGROUND & AIMS
Acinar-to-ductal metaplasia (ADM) is crucial in the development of pancreatic ductal adenocarcinoma. However, our understanding of the induction and resolution of ADM remains limited. We conducted comparative transcriptome analyses to identify conserved mechanisms of ADM in mouse and human.
METHODS
We identified Sox4 among the top up-regulated genes. We validated the analysis by RNA in situ hybridization. We performed experiments in mice with acinar-specific deletion of Sox4 (Ptf1a: CreER; Rosa26; Sox4) with and without an activating mutation in Kras (Kras). Mice were given caerulein to induce pancreatitis. We performed phenotypic analysis by immunohistochemistry, tissue decellularization, and single-cell RNA sequencing.
RESULTS
We demonstrated that Sox4 is reactivated in ADM and pancreatic intraepithelial neoplasias. Contrary to findings in other tissues, Sox4 actually counteracts cellular dedifferentiation and helps maintain tissue homeostasis. Moreover, our investigations unveiled the indispensable role of Sox4 in the specification of mucin-producing cells and tuft-like cells from acinar cells. We identified Sox4-dependent non-cell-autonomous mechanisms regulating the stromal reaction during disease progression. Notably, Sox4-inferred targets are activated upon KRAS inactivation and tumor regression.
CONCLUSIONS
Our results indicate that our transcriptome analysis can be used to investigate conserved mechanisms of tissue injury. We demonstrate that Sox4 restrains acinar dedifferentiation and is necessary for the specification of acinar-derived metaplastic cells in pancreatic injury and cancer initiation and is activated upon Kras ablation and tumor regression in mice. By uncovering novel potential strategies to promote tissue homeostasis, our findings offer new avenues for preventing the development of pancreatic ductal adenocarcinoma.
PubMed: 38729450
DOI: 10.1053/j.gastro.2024.04.031 -
Research Square Dec 2023Sjögren's Disease (SjD) is a systemic autoimmune disease without a clear etiology or effective therapy. Utilizing unbiased single-cell and spatial transcriptomics to...
Sjögren's Disease (SjD) is a systemic autoimmune disease without a clear etiology or effective therapy. Utilizing unbiased single-cell and spatial transcriptomics to analyze human minor salivary glands in health and disease we developed a comprehensive understanding of the cellular landscape of healthy salivary glands and how that landscape changes in SjD patients. We identified novel seromucous acinar cell types and identified a population of PRR4+CST3+WFDC2- seromucous acinar cells that are particularly targeted in SjD. Notably, GZMK+CD8 T cells, enriched in SjD, exhibited a cytotoxic phenotype and were physically associated with immune-engaged epithelial cells in disease. These findings shed light on the immune response's impact on transitioning acinar cells with high levels of secretion and explain the loss of this specific cell population in SjD. This study explores the complex interplay of varied cell types in the salivary glands and their role in the pathology of Sjögren's Disease.
PubMed: 38196575
DOI: 10.21203/rs.3.rs-3601404/v1 -
Gut Jul 2023Increasing evidence implicates mutation-induced protein misfolding and endoplasm reticulum (ER) stress in the pathophysiology of chronic pancreatitis (CP). The paucity...
OBJECTIVE
Increasing evidence implicates mutation-induced protein misfolding and endoplasm reticulum (ER) stress in the pathophysiology of chronic pancreatitis (CP). The paucity of animal models harbouring genetic risk variants has hampered our understanding of how misfolded proteins trigger CP. We previously showed that pancreatic triglyceride lipase (PNLIP) p.T221M, a variant associated with steatorrhoea and possibly CP in humans, misfolds and elicits ER stress in vitro suggesting proteotoxicity as a potential disease mechanism. Our objective was to create a mouse model to determine if PNLIP p.T221M causes CP and to define the mechanism.
DESIGN
We created a mouse model of p.T221M and characterised the structural and biochemical changes in the pancreas aged 1-12 months. We used multiple methods including histochemistry, immunostaining, transmission electron microscopy, biochemical assays, immunoblotting and qPCR.
RESULTS
We demonstrated the hallmarks of human CP in p.T221M homozygous mice including progressive pancreatic atrophy, acinar cell loss, fibrosis, fatty change, immune cell infiltration and reduced exocrine function. Heterozygotes also developed CP although at a slower rate. Immunoblot showed that pancreatic PNLIP T221M misfolded as insoluble aggregates. The level of aggregates in homozygotes declined with age and was much lower in heterozygotes at all ages. The p.T221M pancreas had increased ER stress evidenced by dilated ER, increased (BiP) mRNA abundance and a maladaptive unfolded protein response leading to upregulation of (CHOP), nuclear factor-κB and cell death.
CONCLUSION
Expression of PNLIP p.T221M in a preclinical mouse model results in CP caused by ER stress and proteotoxicity of misfolded mutant PNLIP.
Topics: Mice; Humans; Animals; Pancreatitis, Chronic; Pancreas; Acinar Cells; Endoplasmic Reticulum Stress; Unfolded Protein Response; Endoplasmic Reticulum Chaperone BiP
PubMed: 36631248
DOI: 10.1136/gutjnl-2022-327960 -
Diagnostics (Basel, Switzerland) Aug 2023Several solid lesions can be found within the pancreas mainly arising from the exocrine and endocrine pancreatic tissue. Among all pancreatic malignancies, the most... (Review)
Review
Several solid lesions can be found within the pancreas mainly arising from the exocrine and endocrine pancreatic tissue. Among all pancreatic malignancies, the most common subtype is pancreatic ductal adenocarcinoma (PDAC), to a point that pancreatic cancer and PDAC are used interchangeably. But, in addition to PDAC, and to the other most common and well-known solid lesions, either related to benign conditions, such as pancreatitis, or not so benign, such as pancreatic neuroendocrine neoplasms (pNENs), there are solid pancreatic lesions considered rare due to their low incidence. These lesions may originate from a cell line with a differentiation other than exocrine/endocrine, such as from the nerve sheath as for pancreatic schwannoma or from mesenchymal cells as for solitary fibrous tumour. These rare solid pancreatic lesions may show a behaviour that ranges in a benign to highly aggressive malignant spectrum. This review includes cases of an intrapancreatic accessory spleen, pancreatic tuberculosis, solid serous cystadenoma, solid pseudopapillary tumour, pancreatic schwannoma, purely intraductal neuroendocrine tumour, pancreatic fibrous solitary tumour, acinar cell carcinoma, undifferentiated carcinoma with osteoclastic-like giant cells, adenosquamous carcinoma, colloid carcinoma of the pancreas, primary leiomyosarcoma of the pancreas, primary and secondary pancreatic lymphoma and metastases within the pancreas. Therefore, it is important to determine the correct diagnosis to ensure optimal patient management. Because of their rarity, their existence is less well known and, when depicted, in most cases incidentally, the correct diagnosis remains challenging. However, there are some typical imaging features present on cross-sectional imaging modalities that, taken into account with the clinical and biological context, contribute substantially to achieve the correct diagnosis.
PubMed: 37627978
DOI: 10.3390/diagnostics13162719 -
Japanese Journal of Clinical Oncology Mar 2024Pancreatic acinar cell carcinoma is a rare form (0.2-4.3%) of pancreatic neoplasm with unique clinical and molecular characteristics, which largely differ from... (Review)
Review
Pancreatic acinar cell carcinoma is a rare form (0.2-4.3%) of pancreatic neoplasm with unique clinical and molecular characteristics, which largely differ from pancreatic ductal adenocarcinoma. Pancreatic acinar cell carcinoma occurs more frequently in males and can occur in children. Serum lipase is elevated in 24-58% of patients with pancreatic acinar cell carcinoma. Pancreatic acinar cell carcinomas tend to be large at diagnosis (median tumour size: ~5 cm) and are frequently located in the pancreas head. Radiologically, pancreatic acinar cell carcinoma generally exhibits a solid appearance; however, necrosis, cystic changes and intratumoral haemorrhage can occur in larger lesions. Immunostaining is essential for the definitive diagnosis of pancreatic acinar cell carcinoma. Compared with pancreatic ductal adenocarcinoma, pancreatic acinar cell carcinoma has a more favourable prognosis. Although radical surgery is recommended for patients with pancreatic acinar cell carcinoma who do not have distant metastases, the recurrence rate is high. The effectiveness of adjuvant therapy for pancreatic acinar cell carcinoma is unclear. The response to FOLFIRINOX is generally favourable, and some patients achieve a complete response. Pancreatic acinar cell carcinoma has a different genomic profile compared with pancreatic ductal adenocarcinoma. Although genomic analyses have shown that pancreatic acinar cell carcinoma rarely has KRAS, TP53 and CDKN2A mutations, it has a higher prevalence of homologous recombination-related genes, including BRCA1/2 and ATM, than pancreatic ductal adenocarcinoma, suggesting high sensitivity to platinum-containing regimens and PARP inhibitors. Targeted therapies for genomic alternations are beneficial. Therefore, genetic testing is important for patients with pancreatic acinar cell carcinoma to choose the optimal therapeutic strategy.
Topics: Male; Child; Humans; Pancreatic Neoplasms; Carcinoma, Acinar Cell; Antineoplastic Combined Chemotherapy Protocols; BRCA1 Protein; BRCA2 Protein; Carcinoma, Pancreatic Ductal
PubMed: 38109477
DOI: 10.1093/jjco/hyad176 -
Nature Communications Oct 2023Exocrine acinar cells in salivary glands (SG) are critical for oral health and loss of functional acinar cells is a major clinical challenge. Fibroblast growth factor...
Exocrine acinar cells in salivary glands (SG) are critical for oral health and loss of functional acinar cells is a major clinical challenge. Fibroblast growth factor receptors (FGFR) are essential for early development of multiple organs, including SG. However, the role of FGFR signaling in specific populations later in development and during acinar differentiation are unknown. Here, we use scRNAseq and conditional deletion of murine FGFRs in vivo to identify essential roles for FGFRs in craniofacial, early SG development and progenitor function during duct homeostasis. Importantly, we also discover that FGFR2 via MAPK signaling is critical for seromucous acinar differentiation and secretory gene expression, while FGFR1 is dispensable. We show that FGF7, expressed by myoepithelial cells (MEC), activates the FGFR2-dependent seromucous transcriptional program. Here, we propose a model where MEC-derived FGF7 drives seromucous acinar differentiation, providing a rationale for targeting FGFR2 signaling in regenerative therapies to restore acinar function.
Topics: Animals; Mice; Cell Differentiation; Homeostasis; Orosomucoid; Salivary Glands; Signal Transduction
PubMed: 37838739
DOI: 10.1038/s41467-023-42243-0 -
Nature Communications Jan 2024Animal studies have demonstrated the ability of pancreatic acinar cells to transform into pancreatic ductal adenocarcinoma (PDAC). However, the tumorigenic potential of...
Animal studies have demonstrated the ability of pancreatic acinar cells to transform into pancreatic ductal adenocarcinoma (PDAC). However, the tumorigenic potential of human pancreatic acinar cells remains under debate. To address this gap in knowledge, we expand sorted human acinar cells as 3D organoids and genetically modify them through introduction of common PDAC mutations. The acinar organoids undergo dramatic transcriptional alterations but maintain a recognizable DNA methylation signature. The transcriptomes of acinar organoids are similar to those of disease-specific cell populations. Oncogenic KRAS alone do not transform acinar organoids. However, acinar organoids can form PDAC in vivo after acquiring the four most common driver mutations of this disease. Similarly, sorted ductal cells carrying these genetic mutations can also form PDAC, thus experimentally proving that PDACs can originate from both human acinar and ductal cells. RNA-seq analysis reveal the transcriptional shift from normal acinar cells towards PDACs with enhanced proliferation, metabolic rewiring, down-regulation of MHC molecules, and alterations in the coagulation and complement cascade. By comparing PDAC-like cells with normal pancreas and PDAC samples, we identify a group of genes with elevated expression during early transformation which represent potential early diagnostic biomarkers.
Topics: Animals; Humans; Transcriptome; Pancreatic Neoplasms; Carcinoma, Pancreatic Ductal; Carcinogenesis; Acinar Cells; Gene Expression Profiling; Proto-Oncogene Proteins p21(ras)
PubMed: 38280869
DOI: 10.1038/s41467-024-45097-2 -
Frontiers in Microbiology 2023Acute pancreatitis is caused by trypsinogen activation in acinar cells caused by various injury forms (gallstone, high triglycerides, alcohol, etc.). Viral pancreatitis... (Review)
Review
Acute pancreatitis is caused by trypsinogen activation in acinar cells caused by various injury forms (gallstone, high triglycerides, alcohol, etc.). Viral pancreatitis is a clinically rare disease type, which is easily neglected by clinicians and causes serious adverse consequences. Viral pancreatitis involves the entry of viruses into pancreatic cells, triggering inflammation, immune response activation, and enzymatic autodigestion, leading to tissue damage and potential complications. At present, there are few available reports on viral pancreatitis, most of which are case reports. This review brings attention to clinicians by describing the incidence of viral pancreatitis to enhance clinical understanding and patient care.
PubMed: 38420214
DOI: 10.3389/fmicb.2023.1326837 -
Bioscience Reports Jul 2023Obesity, characterized by accumulation of adipose, is usually accompanied by hyperlipidemia and abnormal glucose metabolism, which destroys the function and structure of...
Obesity, characterized by accumulation of adipose, is usually accompanied by hyperlipidemia and abnormal glucose metabolism, which destroys the function and structure of islet β cells. However, the exact mechanism of islet deterioration caused by obesity has not yet been fully elucidated. Here, we fed C57BL/6 mice with a high-fat diet (HFD) for 2 (2M group) and 6 months (6M group) to construct obesity mouse models. Then, RNA-based sequencing was used to identify the molecular mechanisms in HFD-induced islet dysfunction. Compared with the control diet, a total of 262 and 428 differentially expressed genes (DEGs) were identified from islets of the 2M and 6M groups, respectively. GO and KEGG enrichment analysis revealed that the DEGs up-regulated in both the 2M and 6M groups are mainly enriched in response to endoplasmic reticulum stress and the pancreatic secretion pathway. DEGs down-regulated in both the 2M and 6M groups are mainly enriched in the neuronal cell body and protein digestion and absorption pathway. Notably, along with the HFD feeding, mRNA expression of islet cell markers was significantly down-regulated, such as Ins1, Pdx1, MafA (β cell), Gcg, Arx (α cell), Sst (δcell), and Ppy (PP cell). In contrast, mRNA expression of acinar cell markers was remarkably up-regulated, such as Amy1, Prss2, and Pnlip. Besides, a large number of collagen genes were down-regulated, such as Col1a1, Col6a6, and Col9a2. Overall, our study provides a full-scale DEG map regarding HFD-induced islet dysfunction, which was helpful to understand the underlying molecular mechanism of islet deterioration further.
Topics: Mice; Animals; Diet, High-Fat; Transcriptome; Mice, Inbred C57BL; Obesity; Glucagon-Secreting Cells; RNA, Messenger; Insulin
PubMed: 37293973
DOI: 10.1042/BSR20230501 -
Cell Death and Differentiation Jul 2023Oncogenic KRAS activation, inflammation and p53 mutation are key drivers of pancreatic cancer (PC) development. Here we report iASPP, an inhibitor of p53, as a...
Oncogenic KRAS activation, inflammation and p53 mutation are key drivers of pancreatic cancer (PC) development. Here we report iASPP, an inhibitor of p53, as a paradoxical suppressor of inflammation and oncogenic KRAS-driven PC tumorigenesis. iASPP suppresses PC onset driven by KRAS alone or KRAS in combination with mutant p53. iASPP deletion limits acinar-to-ductal metaplasia (ADM) in vitro but accelerates inflammation and KRAS-induced ADM, pancreatitis and PC tumorigenesis in vivo. KRAS/iASPP tumours are well-differentiated classical PCs and their derivative cell lines form subcutaneous tumours in syngeneic and nude mice. Transcriptomically, either iASPP deletion or p53 mutation in the KRAS background altered the expression of an extensively overlapping gene set, comprised primarily of NF-κB and AP1-regulated inflammatory genes. All these identify iASPP as a suppressor of inflammation and a p53-independent oncosuppressor of PC tumorigenesis.
Topics: Animals; Mice; Carcinogenesis; Carcinoma, Pancreatic Ductal; Cell Transformation, Neoplastic; Inflammation; Mice, Nude; Pancreatic Neoplasms; Proto-Oncogene Proteins p21(ras); Signal Transduction; Tumor Suppressor Protein p53
PubMed: 37270580
DOI: 10.1038/s41418-023-01168-3