Decreased calmodulin recruitment triggers PMCA4 dysfunction and pancreatic injury in cystic fibrosis

ABSTRACTExocrine pancreatic damage is a common complication of cystic fibrosis (CF), which can significantly debilitate the quality of life and life expectancy of CF patients. The cystic fibrosis transmembrane conductance regulator (CFTR) has a major role in pancreatic ductal ion secretion, however, it presumably has an influence on intracellular signaling as well. Here we describe in multiple model systems, including iPSC-derived human pancreatic organoids from CF patients, that the activity of PMCA4 is impaired by the decreased expression of CFTR in ductal cells. The regulation of PMCA4, which colocalizes and physically interacts with CFTR on the apical membrane of the ductal cells, is dependent on the calmodulin binding ability of CFTR. Moreover, CFTR seems to be involved in the process of the apical recruitment of calmodulin, which enhances its role in calcium signaling and homeostasis. Sustained intracellular Ca2+ elevation in CFTR KO cells undermined the mitochondrial function and increased apoptosis. Based on these, the prevention of sustained intracellular Ca2+ overload may improve the exocrine pancreatic function and may have a potential therapeutic aspect in CF.

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Impaired Regulation of PMCA Activity by Defective CFTR Expression Promotes Epithelial Cell Damage in Alcoholic Pancreatitis and Hepatitis

10.21203/rs.3.rs-1228523/v1 ◽

2022 ◽

Author(s):

Tamara Madacsy ◽

Árpád Varga ◽

Noémi Papp ◽

Bálint Tél ◽

Petra Pallagi ◽

...

Keyword(s):

Epithelial Cells ◽

Intracellular Signaling ◽

Alcoholic Hepatitis ◽

Cell Damage ◽

Alcoholic Pancreatitis ◽

Ductal Cells ◽

Ion Secretion ◽

Pancreatic Ductal Cells ◽

Intracellular Ca ◽

The Impact

Abstract Background and aims. Alcoholic pancreatitis and hepatitis are frequent, potentially lethal diseases with limited treatment options. Our previous study reported that the expression of CFTR Cl- channel is impaired by ethanol in pancreatic ductal cells leading to more severe alcohol-induced pancreatitis. In addition to determining epithelial ion secretion, CFTR has multiple interactions with other proteins, which may influence intracellular Ca2+ signaling. Thus, we aimed to investigate the impact of ethanol-mediated CFTR damage on intracellular Ca2+ homeostasis in pancreatic ductal epithelial cells and cholangiocytes.Methods. Human and mouse pancreas and liver samples and ex vivo organoids were used to study ion secretion, intracellular signaling and protein expression and interaction. The effect of PMCA4 inhibition was analysed in a mouse model of alcohol-induced pancreatitis.Results. The decreased CFTR expression impaired PMCA function and resulted in sustained intracellular Ca2+ elevation in ethanol-treated and mouse and human pancreatic organoids. Liver samples derived from alcoholic hepatitis patients and ethanol-treated mouse liver organoids showed decreased CFTR expression and function, and impaired PMCA4 activity. PMCA4 co-localizes and physically interacts with CFTR on the apical membrane of polarized epithelial cells, where CFTR-dependent calmodulin recruitment determines PMCA4 activity. The sustained intracellular Ca2+ elevation in the absence of CFTR inhibited mitochondrial function and was accompanied with increased apoptosis in pancreatic epithelial cells and PMCA4 inhibition increased the severity of alcohol-induced AP in mice.Conclusion. Our results suggest that improving Ca2+ extrusion in epithelial cells may be a potential novel therapeutic approach to protect the exocrine pancreatic function in alcoholic pancreatitis and prevent the development of cholestasis in alcoholic hepatitis.

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FEATURES OF CALCIUM HOMEOSTASIS AND CALCIUM SIGNALING IN NEURONS

Vestnik ◽

10.53065/kaznmu.2021.95.99.044 ◽

2021 ◽

pp. 208-214

Author(s):

Б.К. Кайрат ◽

С.Т. Тулеуханов ◽

В.П. Зинченко

Keyword(s):

Plasma Membrane ◽

Calcium Signaling ◽

Calcium Binding ◽

Intracellular Signaling ◽

Cell Damage ◽

Compensatory Mechanisms ◽

Physiological Processes ◽

Intracellular Ca ◽

Ca Ions ◽

Ca Homeostasis

Ионы Са являются основным мессенджером в регуляции физиологических функций клеток. Внутриклеточном пространстве ионы Ca могут свободно состоянии диффундироваться в различных частях цитоплазмы, в то же время значительное количество Ca в связанном виде накапливается в различных внутриклеточных депо или в составе кальций-связывающих белков. Регуляция физиологических процессов с ионами внутриклеточного Са происходит в диапазоне концентраций 10 М, тогда как концентрация Са во внеклеточном пространстве выше и составляет 10 М, для поддержании градиента концентраций в клетках имеются важные Са транспортирующие системы плазматической мембраны, эндоплазматического ретикулума и митохондрий. В нейронах функционируют внутриклеточные ферменты и белки плазматической мембраны для поддержания Са-гомеостаза и реализации механизмов внутриклеточной сигнализации для обеспечения жизнедеятельности в выживании клеток. Нарушение или гиперактивация одного или нескольких механизмов кальциевой сигнализации может привести к повреждению и гибели нейронов в случае отсутствия компенсаторных механизмов. Ca ions are a key messenger for the regulation of most of the physiological functions of cells. Inside the cell, Ca ions can freely diffuse in various parts of the cytoplasm, but a significant amount of Ca is also bound in various intracellular depots or in the form of calcium-binding proteins. The regulation of physiological processes by intracellular Ca ions occurs in the concentration range of 10 M, and the concentration of Ca in the extracellular space is higher and is 10 M, and to maintain this concentration gradient, cells have Ca-transporting systems of the plasma membrane, endoplasmic reticulum and mitochondria. In neurons, a large number of intracellular enzymes and plasma membrane proteins function to maintain Ca-homeostasis and implement intracellular signaling mechanisms to ensure vital activity in the survival of cells. Violation or hyperactivation of one or more mechanisms of calcium signaling can lead to cell damage and death in the absence of compensatory mechanisms.

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Personalized medicine for cystic fibrosis: Establishing human model systems

Pediatric Pulmonology ◽

10.1002/ppul.23233 ◽

2015 ◽

Vol 50 (S40) ◽

pp. S14-S23 ◽

Cited By ~ 18

Author(s):

Hongmei Mou ◽

Karissa Brazauskas ◽

Jayaraj Rajagopal

Keyword(s):

Cystic Fibrosis ◽

Personalized Medicine ◽

Model Systems ◽

Human Model

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Topology Preservation and Cooperative Learning in Identification of Multiple Model Systems

IEEE Transactions on Neural Networks ◽

10.1109/tnn.2008.2003285 ◽

2008 ◽

Vol 19 (12) ◽

pp. 2065-2072 ◽

Cited By ~ 10

Author(s):

Jianbo Liu ◽

Dragan Djurdjanovic

Keyword(s):

Cooperative Learning ◽

Model Systems ◽

Multiple Model ◽

Topology Preservation

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Increased Levels of Erythropoietin in Nipple Aspirate Fluid and in Ductal Cells from Breast Cancer Patients

Analytical Cellular Pathology ◽

10.1155/2008/812193 ◽

2008 ◽

Vol 30 (1) ◽

pp. 51-61

Author(s):

Ferdinando Mannello ◽

Laura Fabbri ◽

Eleonora Ciandrini ◽

Gaetana A. Tonti

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Cell Lines ◽

Cancer Cell ◽

Intracellular Signaling ◽

Tnm Classification ◽

Cancer Cell Lines ◽

Breast Cancer Cell Lines ◽

Serum Samples ◽

Ductal Cells

Background: Erythropoietin (Epo) is an important regulator of erythropoiesis, and controls proliferation and differentiation of both erythroid and non-erythroid tissues. Epo is actively synthesized by breast cells during lactation, and also plays a role in breast tissues promoting hypoxia-induced cancer initiation. Our aims are to perform an exploratory investigation on the Epo accumulation in breast secretions from healthy and cancer patients and its localization in breast cancer cells.Methods: Epo was determined by ELISA, immunoprecipitation, western blot and immunocytochemical analyses in 130 Nipple Aspirate Fluids (NAF) from 102 NoCancer and 28 Breast Cancer (BC) patients, comparing results with those found in 10 milk, 45 serum samples and breast cancer cell lines.Results: Epo levels in NAFs were significantly higher than those in milk and serum. No difference in Epo electrophoretic mobility was found among NAF, milk and serum samples, and conditioned cell culture medium. Immunolocalization of intracellular Epo in ductal cells floating in BC NAFs was similar to those of cancer cell lines. No significant correlation between TNM classification and Epo in NAFs from BC patients was found. Significantly higher Epo concentration was found in NAF from BC patients compared to NoCancer.Conclusion: We demonstrate that breast epithelial cells are a source of Epo in breast microenvironment, suggesting the presence of a paracrine/autocrine Epo function in NAFs, triggering off intracellular signaling cascade with subsequent BC initiation.

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Serum Immunoreactive Pancreatic Lipase and Cationic Trypsinogen for the Assessment of Exocrine Pancreatic Function in Older Patients With Cystic Fibrosis

PEDIATRICS ◽

10.1542/peds.77.3.301 ◽

1986 ◽

Vol 77 (3) ◽

pp. 301-306

Author(s):

Geoffrey Cleghorn ◽

Lynne Benjamin ◽

Mary Corey ◽

Gordon Forstner ◽

Francesco Dati ◽

...

Keyword(s):

Cystic Fibrosis ◽

Pancreatic Lipase ◽

Elevated Serum ◽

Serum Levels ◽

Exocrine Pancreatic Function ◽

Pancreatic Function ◽

Exocrine Function ◽

Serum Lipase ◽

Significant Difference ◽

Cationic Trypsinogen

Indirect and qualitative tests of pancreatic function are commonly used to screen patients with cystic fibrosis for pancreatic insufficiency. In an attempt to develop a more quantitative assessment, we compared the usefulness of measuring serum pancreatic lipase using a newly developed enzyme-linked immunosorbent immunoassay with that of cationic trypsinogen using a radioimmunoassay in the assessment of exocrine pancreatic function in patients with cystic fibrosis. Previously, we have shown neither lipase nor trypsinogen to be of use in assessing pancreatic function prior to 5 years of age because the majority of patients with cystic fibrosis in early infancy have elevated serum levels regardless of pancreatic function. Therefore, we studied 77 patients with cystic fibrosis older than 5 years of age, 41 with steatorrhea and 36 without steatorrhea. In addition, 28 of 77 patients consented to undergo a quantitative pancreatic stimulation test. There was a significant difference between the steatorrheic and nonsteatorrheic patients with the steatorrheic group having lower lipase and trypsinogen values than the nonsteatorrheic group (P <.001). Sensitivities and specificities in detecting steatorrhea were 95% and 86%, respectively, for lipase and 93% and 92%, respectively, for trypsinogen. No correlations were found between the serum levels of lipase and trypsinogen and their respective duodenal concentrations because of abnormally high serum levels of both enzymes found in some nonsteatorrheic patients. We conclude from this study that both serum lipase and trypsinogen levels accurately detect steatorrhea in patients with cystic fibrosis who are older than 5 years but are imprecise indicators of specific pancreatic exocrine function above the level needed for normal fat absorption.

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Extracellular UTP stimulates electrogenic bicarbonate secretion across CFTR knockout gallbladder epithelium

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.2000.279.1.g132 ◽

2000 ◽

Vol 279 (1) ◽

pp. G132-G138 ◽

Cited By ~ 23

Author(s):

Lane L. Clarke ◽

Matthew C. Harline ◽

Lara R. Gawenis ◽

Nancy M. Walker ◽

John T. Turner ◽

...

Keyword(s):

Cystic Fibrosis ◽

Short Circuit ◽

Ussing Chamber ◽

Short Circuit Current ◽

Receptor Activation ◽

Biliary Disease ◽

Anion Conductance ◽

Intracellular Ca ◽

Ph Stat ◽

Chamber Studies

The loss of cystic fibrosis transmembrane conductance regulator (CFTR)-mediated transepithelial HCO3 − secretion contributes to the pathogenesis of pancreatic and biliary disease in cystic fibrosis (CF) patients. Recent studies have investigated P2Y2 nucleotide receptor agonists, e.g., UTP, as a means to bypass the CFTR defect by stimulating Ca2+-activated Cl− secretion. However, the value of this treatment in facilitating transepithelial HCO3 − secretion is unknown. Gallbladder mucosae from CFTR knockout mice were used to isolate the Ca2+-dependent anion conductance during activation of luminal P2Y2receptors. In Ussing chamber studies, UTP stimulated a transient peak in short-circuit current ( I sc) that declined to a stable plateau phase lasting 30–60 min. The plateau I sc after UTP was Cl− independent, HCO3 − dependent, insensitive to bumetanide, and blocked by luminal DIDS. In pH stat studies, luminal UTP increased both I sc and serosal-to-mucosal HCO3 − flux ( J s→m) during a 30-min period. Substitution of Cl− with gluconate in the luminal bath to inhibit Cl−/HCO3 −exchange did not prevent the increase in J s→mand I sc during UTP. In contrast, luminal DIDS completely inhibited UTP-stimulated increases in J s→m and I sc. We conclude that P2Y2 receptor activation results in a sustained (30–60 min) increase in electrogenic HCO3 − secretion that is mediated via an intracellular Ca2+-dependent anion conductance in CF gallbladder.

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Growing Structure Multiple Model Systems for Anomaly Detection and Fault Diagnosis

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.3155004 ◽

2009 ◽

Vol 131 (5) ◽

Cited By ~ 12

Author(s):

Jianbo Liu ◽

Dragan Djurdjanovic ◽

Kenneth Marko ◽

Jun Ni

Keyword(s):

Fault Diagnosis ◽

Anomaly Detection ◽

System Development ◽

Simulation Software ◽

Model Systems ◽

Multiple Model ◽

Detection Scheme ◽

Engine Simulation ◽

Local Decision ◽

Residual Errors

A new anomaly detection scheme based on growing structure multiple model system (GSMMS) is proposed in this paper to detect and quantify the effects of anomalies. The GSMMS algorithm combines the advantages of growing self-organizing networks with efficient local model parameter estimation into an integrated framework for modeling and identification of general nonlinear dynamic systems. The identified model then serves as a foundation for building an effective anomaly detection and fault diagnosis system. By utilizing the information about system operation region provided by the GSMMS, the residual errors can be analyzed locally within each operation region. This local decision making scheme can accommodate for unequally distributed residual errors across different operational regions. The performance of the newly proposed method is evaluated through anomaly detection and quantification in an electronically controlled throttle system, which is simulated using a high-fidelity engine simulation software package provided by a major automotive manufacturer for control system development.

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