The impaired  function of the plasma membrane Ca2+ pump results in  Ca2+ overload and cell damage in CFTR knock out pancreatic ductal cells

Author(s):  
Tamara Madacsy
Pancreatology ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. S31
Author(s):  
Tamara Madacsy ◽  
Julia Fanczal ◽  
Petra Pallagi ◽  
Zoltan Rakonczay ◽  
Peter Hegyi ◽  
...  

2022 ◽  
Author(s):  
Tamara Madacsy ◽  
Árpád Varga ◽  
Noémi Papp ◽  
Bálint Tél ◽  
Petra Pallagi ◽  
...  

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.


2019 ◽  
Vol 14 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Aravinth P. Jawahar ◽  
Siddharth Narayanan ◽  
Gopalakrishnan Loganathan ◽  
Jithu Pradeep ◽  
Gary C. Vitale ◽  
...  

Islet cell auto-transplantation is a novel strategy for maintaining blood glucose levels and improving the quality of life in patients with chronic pancreatitis (CP). Despite the many recent advances associated with this therapy, obtaining a good yield of islet infusate still remains a pressing challenge. Reprogramming technology, by making use of the pancreatic exocrine compartment, can open the possibility of generating novel insulin-producing cells. Several lineage-tracing studies present evidence that exocrine cells undergo dedifferentiation into a progenitor-like state from which they can be manipulated to form insulin-producing cells. This review will present an overview of recent reports that demonstrate the potential of utilizing pancreatic ductal cells (PDCs) for reprogramming into insulin- producing cells, focusing on the recent advances and the conflicting views. A large pool of ductal cells is released along with islets during the human islet isolation process, but these cells are separated from the pure islets during the purification process. By identifying and improving existing ductal cell culture methods and developing a better understanding of mechanisms by which these cells can be manipulated to form hormone-producing islet-like cells, PDCs could prove to be a strong clinical tool in providing an alternative beta cell source, thus helping CP patients maintain their long-term glucose levels.


2021 ◽  
Vol 22 (13) ◽  
pp. 7232
Author(s):  
Gloria Lazzeri ◽  
Carla L. Busceti ◽  
Francesca Biagioni ◽  
Cinzia Fabrizi ◽  
Gabriele Morucci ◽  
...  

Norepinephrine (NE) neurons and extracellular NE exert some protective effects against a variety of insults, including methamphetamine (Meth)-induced cell damage. The intimate mechanism of protection remains difficult to be analyzed in vivo. In fact, this may occur directly on target neurons or as the indirect consequence of NE-induced alterations in the activity of trans-synaptic loops. Therefore, to elude neuronal networks, which may contribute to these effects in vivo, the present study investigates whether NE still protects when directly applied to Meth-treated PC12 cells. Meth was selected based on its detrimental effects along various specific brain areas. The study shows that NE directly protects in vitro against Meth-induced cell damage. The present study indicates that such an effect fully depends on the activation of plasma membrane β2-adrenergic receptors (ARs). Evidence indicates that β2-ARs activation restores autophagy, which is impaired by Meth administration. This occurs via restoration of the autophagy flux and, as assessed by ultrastructural morphometry, by preventing the dissipation of microtubule-associated protein 1 light chain 3 (LC3) from autophagy vacuoles to the cytosol, which is produced instead during Meth toxicity. These findings may have an impact in a variety of degenerative conditions characterized by NE deficiency along with autophagy impairment.


2005 ◽  
Vol 333 (4) ◽  
pp. 1153-1159 ◽  
Author(s):  
Ghaffar Muharram ◽  
Anthony Beucher ◽  
Ericka Moerman ◽  
Sandrine Belaı¨ch ◽  
Valéry Gmyr ◽  
...  

2021 ◽  
Author(s):  
J Krüger ◽  
M Breunig ◽  
T Seufferlein ◽  
M Hohwieler ◽  
A Kleger

Vestnik ◽  
2021 ◽  
pp. 208-214
Author(s):  
Б.К. Кайрат ◽  
С.Т. Тулеуханов ◽  
В.П. Зинченко

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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