Project description:In order to compare the gene expression profile of acinar-to-ductal metaplasia (ADM), ductal and acinar cells in the setting of pancreatitis, which were obtained by laser-capture microdissection (LMD) from frozen sections of wild type mice pancreata 2 days after caerulein administration, we performed microarray analysis. ADM has an intermediate property between ductal and acinar cells in the setting of pancreatitis, and Cxcr4 mRNA which is expressed in multipotent pancreatic progenitors, were up-regulated in ADM compared with ductal cells or acinar cells. Notably, in consistent with our immunostaining data, Dclk1 mRNA was highly expressed in ADM cells compared with ductal and acinar cells.
Project description:Acinar cells have been proposed as a cell-of-origin for pancreatic intraepithelial neoplasia (PanIN) after undergoing a highly regulated acinar to ductal metaplasia (ADM) process. ADM can be triggered by pancreatitis causing acinar cells de-differentiate to a ductal-like state. We identify Fra1 (gene name Fosl1) as the most enriched transcription factor during KrasG12D acute pancreatitis mediated injury. We have elucidated the functional role of Fra1 by generating an acinar-specific Fosl1 knockout mouse expressing KrasG12D (Ptf1aCreERT;KrasG12D;Fosl1fl/fl;YFP) . Using single nuclei ATAC-seq and bulk-RNA seq, we used pseudotime analysis and developed a gene-regulatory network governing de-differentiation to demonstrate that Fosl1 knockout mice are delayed in the onset of ADM and accompanying recovery. Fosl1 depletion prevents the pro-inflammatory effects of G-CSF, an ADM-promoting cytokine, suggesting that the G-CSF/Fra1 signaling axis can modulate ADM. Overall, our studies mark the first time a discrete transcriptional factor has been linked to the temporal regulation of ADM.
Project description:Acinar cells have been proposed as a cell-of-origin for pancreatic intraepithelial neoplasia (PanIN) after undergoing a highly regulated acinar to ductal metaplasia (ADM) process. ADM can be triggered by pancreatitis causing acinar cells de-differentiate to a ductal-like state. We identify Fra1 (gene name Fosl1) as the most enriched transcription factor during KrasG12D acute pancreatitis mediated injury. We have elucidated the functional role of Fra1 by generating an acinar-specific Fosl1 knockout mouse expressing KrasG12D (Ptf1aCreERT;KrasG12D;Fosl1fl/fl;YFP) . Using single nuclei ATAC-seq and bulk-RNA seq, we used pseudotime analysis and developed a gene-regulatory network governing de-differentiation to demonstrate that Fosl1 knockout mice are delayed in the onset of ADM and accompanying recovery. Fosl1 depletion prevents the pro-inflammatory effects of G-CSF, an ADM-promoting cytokine, suggesting that the G-CSF/Fra1 signaling axis can modulate ADM. Overall, our studies mark the first time a discrete transcriptional factor has been linked to the temporal regulation of ADM.
Project description:Acinar cells have been proposed as a cell-of-origin for pancreatic intraepithelial neoplasia (PanIN) after undergoing a highly regulated acinar to ductal metaplasia (ADM) process. ADM can be triggered by pancreatitis causing acinar cells de-differentiate to a ductal-like state. We identify Fra1 (gene name Fosl1) as the most enriched transcription factor during KrasG12D acute pancreatitis mediated injury. We have elucidated the functional role of Fra1 by generating an acinar-specific Fosl1 knockout mouse expressing KrasG12D (Ptf1aCreERT;KrasG12D;Fosl1fl/fl;YFP) . Using single nuclei ATAC-seq and bulk-RNA seq, we used pseudotime analysis and developed a gene-regulatory network governing de-differentiation to demonstrate that Fosl1 knockout mice are delayed in the onset of ADM and accompanying recovery. Fosl1 depletion prevents the pro-inflammatory effects of G-CSF, an ADM-promoting cytokine, suggesting that the G-CSF/Fra1 signaling axis can modulate ADM. Overall, our studies mark the first time a discrete transcriptional factor has been linked to the temporal regulation of ADM.
Project description:Pancreatic ductal adenocarcinoma (PDAC) is the most important histological subtype of pancreatic cancer, accounting for approximately 90% of all pancreatic cancers.Acinar to ductal metaplasia (ADM) is a recently recognized, yet less well-studied, precursor lesion of PDAC developed in the setting of chronic pancreatitis. Through digital spatial mRNA profiling, we compared ADM and adjacent PDAC tissues from patient samples to unveil the bridging genes, bridging signaling pathway and bridging molecular function during the malignant transformation of pancreatitis.
Project description:Aberrant acinar to ductal metaplasia (ADM), one of the earliest events involved in exocrine pancreatic cancer development, is typically studied using pancreata from transgenic mouse models. We used primary, human pancreatic acinar cells to evaluate the transcriptional profile during the course of ADM.
Project description:To determine the molecular basis of gene regulation in pancreatic ductal epithelial cells, we developed methods for the isolation of this cell population during mouse development and normal adult homeostasis, as well as in conditions with ductal features (acinar-to-ductal metaplasia (ADM), pancreatic intraepithelial neoplasia (PanIN) and pancreatic ductal adenocarcinoma (PDAC)). Our technique utilizes the specificity of Dolichos biflorus Agglutinin (DBA) lectin marking the entire normal ductal tree, including terminal intercalated ducts (putative sites of stem or progenitor cells) and ductal structures in ADM and PanIN. We used ferromagnetic-labeled DBA lectin to isolate ductal structures. Ductal cells were isolated under the following conditions: (1) Embryonic Development in wild type mice: E14.5, E15.5, E16.5, and postnatal day 1 (P1); (2) Injury and regeneration (pancreatitis) 0, 1, 3, 5 days following cerulein-induced acute pancreatitis. Cerulein is a cholecystokinin analog which produces a self-limited pancreatitis with injury and subsequent regeneration and repair, completed five days after insult; and (3) Pdx1-Cre;LSL-KrasG12D/+ mice aged 10 and 20 weeks that harbor PanIN lesions and a subset develop PDAC. Ductal/PanIN cells were isolated from these mice and appropriate control mice (Pdx1-Cre;Kras+/+).
Project description:Acinar ductal metaplasia (ADM), is believed to be one of the earliest precursor lesions towards the development of pancreatic ductal adenocarcinoma, and maintaining the pancreatic acinar cell phenotype suppresses tumor formation. We report that pStat3 and HDAC inhibition can attenuate ADM in vitro and TSA treatment reverses the dedifferentiated phenotype to one that is more acinar. Our findings suggest that pharmacological inhibition or reversal of pancreatic ADM represents a potential therapeutic strategy for blocking ductal reprogramming of acinar cells.
Project description:Inflammation is a major risk factor for pancreatic ductal adenocarcinoma (PDAC). When occurring in the context of pancreatitis, mutations of KRAS accelerate tumor development. We discovered 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, epithelial cells of the pancreas display an enduring adaptive response associated with sustained transcriptional and epigenetic reprogramming. Such adaptation enables the prompt reactivation of acinar-to-ductal metaplasia (ADM) upon subsequent inflammatory events, thus efficiently limiting tissue damage via rapid decrease of zymogen production. We propose that since activating mutations of KRAS maintain an irreversible ADM, they may be beneficial and under strong positive selection in the context of recurrent pancreatitis.
Project description:Inflammation is a major risk factor for pancreatic ductal adenocarcinoma (PDAC). When occurring in the context of pancreatitis, mutations of KRAS accelerate tumor development. We discovered 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, epithelial cells of the pancreas display an enduring adaptive response associated with sustained transcriptional and epigenetic reprogramming. Such adaptation enables the prompt reactivation of acinar-to-ductal metaplasia (ADM) upon subsequent inflammatory events, thus efficiently limiting tissue damage via rapid decrease of zymogen production. We propose that since activating mutations of KRAS maintain an irreversible ADM, they may be beneficial and under strong positive selection in the context of recurrent pancreatitis.