The tissue-specific regulation of the carboxyl ester lipase gene in exocrine pancreas differs significantly between mouse and human.
Ontology highlight
ABSTRACT:
SUBMITTER: Kannius-Janson M
PROVIDER: S-EPMC1221372 | biostudies-other | 2000 Oct
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Maturity-onset diabetes of the young, type 8 (MODY8) is characterized by a syndrome of autosomal dominantly inherited diabetes and exocrine pancreatic dysfunction. It is caused by deletion mutations in the last exon of the carboxyl ester lipase (CEL) gene, resulting in a CEL protein with increased tendency to aggregate. In this study we investigated the intracellular distribution of the wild type (WT) and mutant (MUT) CEL proteins in cellular models. We found that both CEL-WT and CEL-MUT were secreted via the endoplasmic reticulum and Golgi compartments. However, their subcellular distributions differed, as only CEL-MUT was observed as an aggregate at the cell surface and inside large cytoplasmic vacuoles. Many of the vacuoles were identified as components of the endosomal system, and after its secretion, the mutant CEL protein was re-internalized, transported to the lysosomes, and degraded. Internalization of CEL-MUT also led to reduced viability of pancreatic acinar and beta cells. These findings may have implications for the understanding of how the acinar-specific CEL-MUT protein causes both exocrine and endocrine pancreatic disease.
| S-EPMC4200264 | biostudies-literature
Project description:BackgroundCEL-MODY is a monogenic form of diabetes with exocrine pancreatic insufficiency caused by mutations in CARBOXYL-ESTER LIPASE (CEL). The pathogenic processes underlying CEL-MODY are poorly understood, and the global knockout mouse model of the CEL gene (CELKO) did not recapitulate the disease. We therefore aimed to create and phenotype a mouse model specifically over-expressing mutated CEL in the pancreas.MethodsWe established a monotransgenic floxed (flanking LOX sequences) mouse line carrying the human CEL mutation c.1686delT and crossed it with an elastase-Cre mouse to derive a bitransgenic mouse line with pancreas-specific over-expression of CEL carrying this disease-associated mutation (TgCEL). Following confirmation of murine pancreatic expression of the human transgene by real-time quantitative PCR, we phenotyped the mouse model fed a normal chow and compared it with mice fed a 60% high fat diet (HFD) as well as the effects of short-term and long-term cerulein exposure.ResultsPancreatic exocrine function was normal in TgCEL mice on normal chow as assessed by serum lipid and lipid-soluble vitamin levels, fecal elastase and fecal fat absorption, and the normoglycemic mice exhibited normal pancreatic morphology. On 60% HFD, the mice gained weight to the same extent as controls, had normal pancreatic exocrine function and comparable glucose tolerance even after resuming normal diet and follow up up to 22 months of age. The cerulein-exposed TgCEL mice gained weight and remained glucose tolerant, and there were no detectable mutation-specific differences in serum amylase, islet hormones or the extent of pancreatic tissue inflammation.ConclusionsIn this murine model of human CEL-MODY diabetes, we did not detect mutation-specific endocrine or exocrine pancreatic phenotypes, in response to altered diets or exposure to cerulein.
| S-EPMC3615023 | biostudies-literature
Project description:Studies on pancreatic cell physiology rely on the investigation of exocrine and endocrine cells in vitro. Particularly, in the case of the exocrine tissue these studies have suffered from a reduced functional viability of acinar cells in culture. As a result not only investigations on dispersed acinar cells and isolated acini were limited in their potential, but also prolonged studies on pancreatic exocrine and endocrine cells in an intact pancreatic tissue environment were unfeasible. To overcome these limitations, we aimed to establish a pancreas tissue slice culture platform to allow long-term studies on exocrine and endocrine cells in the intact pancreatic environment. Mouse pancreas tissue slice morphology was assessed to determine optimal long-term culture settings for intact pancreatic tissue. Utilizing optimized culture conditions, cell specificity and function of exocrine acinar cells and endocrine beta cells were characterized over a culture period of 7 days. We found pancreas tissue slices cultured under optimized conditions to have intact tissue specific morphology for the entire culture period. Amylase positive intact acini were present at all time points of culture and acinar cells displayed a typical strong cell polarity. Amylase release from pancreas tissue slices decreased during culture, but maintained the characteristic bell-shaped dose-response curve to increasing caerulein concentrations and a ca. 4-fold maximal over basal release. Additionally, endocrine beta cell viability and function was well preserved until the end of the observation period. Our results show that the tissue slice culture platform provides unprecedented maintenance of pancreatic tissue specific morphology and function over a culture period for at least 4 days and in part even up to 1 week. This analytical advancement now allows mid -to long-term studies on the cell biology of pancreatic disorder pathogenesis and therapy in an intact surrounding in situ.
| S-EPMC3817072 | biostudies-literature
Project description:CEL-maturity onset diabetes of the young (MODY), diabetes with pancreatic lipomatosis and exocrine dysfunction, is due to dominant frameshift mutations in the acinar cell carboxyl ester lipase gene (CEL). As Cel knock-out mice do not express the phenotype and the mutant protein has an altered and intrinsically disordered tandem repeat domain, we hypothesized that the disease mechanism might involve a negative effect of the mutant protein. In silico analysis showed that the pI of the tandem repeat was markedly increased from pH 3.3 in wild-type (WT) to 11.8 in mutant (MUT) human CEL. By stably overexpressing CEL-WT and CEL-MUT in HEK293 cells, we found similar glycosylation, ubiquitination, constitutive secretion, and quality control of the two proteins. The CEL-MUT protein demonstrated, however, a high propensity to form aggregates found intracellularly and extracellularly. Different physicochemical properties of the intrinsically disordered tandem repeat domains of WT and MUT proteins may contribute to different short and long range interactions with the globular core domain and other macromolecules, including cell membranes. Thus, we propose that CEL-MODY is a protein misfolding disease caused by a negative gain-of-function effect of the mutant proteins in pancreatic tissues.
| S-EPMC3186416 | biostudies-literature
Project description:The exocrine portion of the pancreas functions in digestion and preserves pancreatic homeostasis. Learning how this tissue forms during embryogenesis could improve our understanding of human pancreatic diseases. Expression of the homeobox gene Prox1 in the exocrine pancreas changes throughout development in mice. We investigated the role of Prox1 in development of the exocrine pancreas in mice.Mice with pancreas-specific deletion of Prox1 (Prox1(?Panc)) were generated and their pancreatic tissues were analyzed using immunohistochemistry, transmission electron microscopy, histologic techniques, quantitative real-time polymerase chain reaction, immunoblotting, and morphometric analysis.Loss of Prox1 from the pancreas led to multiple exocrine alterations, most notably premature acinar cell differentiation, increased ductal cell proliferation, altered duct morphogenesis, and imbalanced expression of claudin proteins. Prox1(?Panc) mice also had some minor alterations in islet cells, but beta-cell development was not affected. The exocrine congenital defects of Prox1(?Panc) pancreata appeared to initiate a gradual process of deterioration that resulted in extensive loss of acinar cells, lipomatosis, and damage to ductal tissue in adult mice.Pancreas-specific deletion of Prox1 causes premature differentiation of acinar cells and poor elongation of epithelial branches; these defects indicate that Prox1 controls the expansion of tip progenitors in the early developing pancreas. During later stages of embryogenesis, Prox1 appears to regulate duct cell proliferation and morphogenesis. These findings identify Prox1 as an important regulator of pancreatic exocrine development.
| S-EPMC3398795 | biostudies-literature
Project description:Acute lipolysis of visceral fat or circulating triglycerides may worsen acute pancreatitis (AP)-associated local and systemic injury. The pancreas expresses pancreatic triacylglycerol lipase (PNLIP), pancreatic lipase-related protein 2 (PNLIPRP2), and carboxyl ester lipase (CEL), which may leak into the visceral fat or systemic circulation during pancreatitis. We, thus, aimed to determine the pancreatic lipase(s) regulating lipotoxicity during AP. For this AP, associated fat necrosis was analyzed using Western blot analysis. Bile acid (using liquid chromatography-tandem mass spectrometry) and fatty acid (using gas chromatography) concentrations were measured in human fat necrosis. The fat necrosis milieu was simulated in vitro using glyceryl trilinoleate because linoleic acid is increased in fat necrosis. Bile acid requirements to effectively hydrolyze glyceryl trilinoleate were studied using exogenous or overexpressed lipases. The renal cell line (HEK 293) was used to study lipotoxic injury. Because dual pancreatic lipase knockouts are lethal, exocrine parotid acini lacking lipases were used to verify the results. PNLIP, PNLIPRP2, and CEL were increased in fat necrosis. Although PNLIP and PNLIPRP2 were equipotent in inducing lipolysis and lipotoxic injury, CEL required bile acid concentrations higher than in human fat necrosis. The high bile acid requirements for effective lipolysis make CEL an unlikely mediator of lipotoxic injury in AP. It remains to be explored whether PNLIP or PNLIPRP2 worsens AP severity in vivo.
| S-EPMC6547060 | biostudies-literature
Project description:BackgroundEndoplasmic reticulum (ER) stress-inducing variants in several pancreatic secretory enzymes have been associated with pancreatic disease. Multiple variants in CEL, encoding carboxyl ester lipase, are known to cause maturity-onset diabetes of the young (MODY8) but have not been implicated in pancreatic cancer risk.MethodsThe prevalence of ER stress-inducing variants in the CEL gene was compared among pancreatic cancer cases vs. controls. Variants were identified by next-generation sequencing and confirmed by Sanger sequencing. Variants of uncertain significance (VUS) were assessed for their effect on the secretion of CEL protein and variants with reduced protein secretion were evaluated to determine if they induced endoplasmic reticulum stress.ResultsER stress-inducing CEL variants were found in 34 of 986 cases with sporadic pancreatic ductal adenocarcinoma, and 21 of 1045 controls (P = 0.055). Most of the variants were either the CEL-HYB1 variant, the I488T variant, or the combined CEL-HYB1/I488T variant; one case had a MODY8 variant.ConclusionThis case/control analysis finds ER stress-inducing CEL variants are not associated with an increased likelihood of having pancreatic cancer.
| S-EPMC9669157 | biostudies-literature
Project description:The lactating mammary gland and pancreas of mouse constitute the main tissues for synthesis and secretion of a bile-salt-stimulated lipase called carboxyl ester lipase (CEL). In this paper we have analysed the endogenous CEL gene expression in mammary gland. It is shown that the gene is expressed at day 14 of pregnancy, which is synchronous with that of the whey acidic protein (WAP) gene. Even though the CEL and WAP genes are induced at the same time during mammary gland differentiation, their regulation is different with respect to dependence on lactogenic hormones. The high induction of the WAP gene expression due to the activation of signal transducer and activator of transcription (STAT)5 by prolactin has not been observed for the CEL gene, even though it has been demonstrated that both STAT5 isoforms interact with one of the gamma-interferon activation sequence sites in the promoter of the CEL gene. Hence we have demonstrated that the prolactin/STAT5 signal is not involved in a general and significant activation of 'milk genes'. Instead of a direct effect of the lactogenic hormones, the up-regulation of the CEL gene is correlated with an increase in the number of differentiated epithelial cells. Furthermore, promoter studies using the mammary-gland-derived cell line, HC11, show that a major positive element in the CEL gene promoter interacts with a member(s) of the CCAAT-binding transcription factor/nuclear factor 1 family, binding to a palindromic site. Binding of this factor(s) is important for the tissue-specific activation of the CEL gene in the mammary gland, because no activation by this factor(s) was seen in cells of pancreatic origin.
| S-EPMC1219907 | biostudies-other
Project description:Peroxisomal dysfunction unhinges cellular metabolism by causing the accumulation of toxic metabolic intermediates (e.g. reactive oxygen species, very -chain fatty acids, phytanic acid or eicosanoids) and the depletion of important lipid products (e.g. plasmalogens, polyunsaturated fatty acids), leading to various proinflammatory and devastating pathophysiological conditions like metabolic syndrome and age-related diseases including diabetes. Because the peroxisomal antioxidative marker enzyme catalase is low abundant in Langerhans islet cells, peroxisomes were considered scarcely present in the endocrine pancreas. Recently, studies demonstrated that the peroxisomal metabolism is relevant for pancreatic cell functionality. During the postnatal period, significant changes occur in the cell structure and the metabolism to trigger the final maturation of the pancreas, including cell proliferation, regulation of energy metabolism, and activation of signalling pathways. Our aim in this study was to (i) morphometrically analyse the density of peroxisomes in mouse endocrine versus exocrine pancreas and (ii) investigate how the distribution and the abundance of peroxisomal proteins involved in biogenesis, antioxidative defence and fatty acid metabolism change during pancreatic maturation in the postnatal period. Our results prove that endocrine and exocrine pancreatic cells contain high amounts of peroxisomes with heterogeneous protein content indicating that distinct endocrine and exocrine cell types require a specific set of peroxisomal proteins depending on their individual physiological functions. We further show that significant postnatal changes occur in the peroxisomal compartment of different pancreatic cells that are most probably relevant for the metabolic maturation and differentiation of the pancreas during the development from birth to adulthood.
| S-EPMC10313850 | biostudies-literature
Project description:We demonstrate that the binding sites for highly conserved transcription factors vary extensively between human and mouse. We mapped the binding of four tissue-specific transcription factors (FOXA2, HNF1A, HNF4A and HNF6) to 4,000 orthologous gene pairs in hepatocytes purified from human and mouse livers. Despite the conserved function of these factors, from 41% to 89% of their binding events seem to be species specific. When the same protein binds the promoters of orthologous genes, approximately two-thirds of the binding sites do not align.
| S-EPMC3797512 | biostudies-literature