Attenuation of apoptosis in enterocytes by blockade of potassium channels

2005 ◽  
Vol 289 (5) ◽  
pp. G815-G821 ◽  
Author(s):  
Anatoly Grishin ◽  
Henri Ford ◽  
Jin Wang ◽  
Hui Li ◽  
Vicenta Salvador-Recatala ◽  
...  
Keyword(s):  
Apoptotic Cell ◽  
Cell Loss ◽  
Cell Types ◽  
Epithelial Cell Line ◽  
Channel Blockers ◽  
Pharmacological Prevention ◽  
Pharmacological Blockade ◽  
Inflammatory Bowel ◽  
First Time

Apoptosis plays an important role in maintaining the balance between proliferation and cell loss in the intestinal epithelium. Apoptosis rates may increase in intestinal pathologies such as inflammatory bowel disease and necrotizing enterocolitis, suggesting pharmacological prevention of apoptosis as a therapy for these conditions. Here, we explore the feasibility of this approach using the rat epithelial cell line IEC-6 as a model. On the basis of the known role of K+ efflux in apoptosis in various cell types, we hypothesized that K+ efflux is essential for apoptosis in enterocytes and that pharmacological blockade of this efflux would inhibit apoptosis. By probing intracellular [K+] with the K+-sensitive fluorescent dye and measuring the efflux of 86Rb+, we found that apoptosis-inducing treatment with the proteasome inhibitor MG-132 leads to a twofold increase in K+ efflux from IEC-6 cells. Blockade of K+ efflux with tetraethylammonium, 4-aminopyridine, stromatoxin, chromanol 293B, and the recently described K+ channel inhibitor 48F10 prevents DNA fragmentation, caspase activation, release of cytochrome c from mitochondria, and loss of mitochondrial membrane potential. Thus K+ efflux occurs early in the apoptotic program and is required for the execution of later events. Apoptotic K+ efflux critically depends on activation of p38 MAPK. These results demonstrate for the first time the requirement of K+ channel-mediated K+ efflux for progression of apoptosis in enterocytes and suggest the use of K+ channel blockers to prevent apoptotic cell loss occurring in intestinal pathologies.

scholarly journals Interactome Analysis of KIN (Kin17) Shows New Functions of This Protein

2021 ◽  
Vol 43 (2) ◽  
pp. 767-781
Author(s):  
Vanessa Pinatto Gaspar ◽  
Anelise Cardoso Ramos ◽  
Philippe Cloutier ◽  
José Renato Pattaro Junior ◽  
Francisco Ferreira Duarte Junior ◽  
...  
Keyword(s):  
Dna Replication ◽  
Protein Interactions ◽  
Ribosome Biogenesis ◽  
Cell Metabolism ◽  
Cell Types ◽  
Protein Protein Interactions ◽  
Cellular Mechanisms ◽  
Cancerous Cell ◽  
First Time

KIN (Kin17) protein is overexpressed in a number of cancerous cell lines, and is therefore considered a possible cancer biomarker. It is a well-conserved protein across eukaryotes and is ubiquitously expressed in all cell types studied, suggesting an important role in the maintenance of basic cellular function which is yet to be well determined. Early studies on KIN suggested that this nuclear protein plays a role in cellular mechanisms such as DNA replication and/or repair; however, its association with chromatin depends on its methylation state. In order to provide a better understanding of the cellular role of this protein, we investigated its interactome by proximity-dependent biotin identification coupled to mass spectrometry (BioID-MS), used for identification of protein–protein interactions. Our analyses detected interaction with a novel set of proteins and reinforced previous observations linking KIN to factors involved in RNA processing, notably pre-mRNA splicing and ribosome biogenesis. However, little evidence supports that this protein is directly coupled to DNA replication and/or repair processes, as previously suggested. Furthermore, a novel interaction was observed with PRMT7 (protein arginine methyltransferase 7) and we demonstrated that KIN is modified by this enzyme. This interactome analysis indicates that KIN is associated with several cell metabolism functions, and shows for the first time an association with ribosome biogenesis, suggesting that KIN is likely a moonlight protein.

scholarly journals A large panel of chicken cells are invaded in vivo by Salmonella Typhimurium even when depleted of all known invasion factors

Open Biology ◽  
2021 ◽  
Vol 11 (11) ◽  
Author(s):  
S. M. Roche ◽  
S. Holbert ◽  
Y. Le Vern ◽  
C. Rossignol ◽  
A. Rossignol ◽  
...  
Keyword(s):  
Gall Bladder ◽  
Cell Types ◽  
Human Infection ◽  
Cell Tropism ◽  
Wild Type ◽  
Phagocytic Cells ◽  
Bladder Cells ◽  
First Time

Poultry are the main source of human infection by Salmonella . As infected poultry are asymptomatic, identifying infected poultry farms is difficult, thus controlling animal infections is of primary importance. As cell tropism is known to govern disease, our aim was therefore to identify infected host–cell types in the organs of chicks known to be involved in Salmonella infection and investigate the role of the three known invasion factors in this process (T3SS-1, Rck and PagN). Chicks were inoculated with wild-type or isogenic fluorescent Salmonella Typhimurium mutants via the intracoelomic route. Our results show that liver, spleen, gall bladder and aortic vessels could be foci of infection, and that phagocytic and non-phagocytic cells, including immune, epithelial and endothelial cells, are invaded in vivo in each organ. Moreover, a mutant defective for the T3SS-1, Rck and PagN remained able to colonize organs like the wild-type strain and invaded non-phagocytic cells in each organ studied. As the infection of the gall bladder had not previously been described in chicks, invasion of gall bladder cells was confirmed by immunohistochemistry and infection was shown to last several weeks after inoculation. Altogether, for the first time these findings provide insights into cell tropism of Salmonella in relevant organs involved in Salmonella infection in chicks and also demonstrate that the known invasion factors are not required for entry into these cell types.

scholarly journals The Mitochondrial Ca2+ Overload via Voltage-Gated Ca2+ Entry Contributes to an Anti-Melanoma Effect of Diallyl Trisulfide

2020 ◽  
Vol 21 (2) ◽  
pp. 491
Author(s):  
Chinatsu Nakagawa ◽  
Manami Suzuki-Karasaki ◽  
Miki Suzuki-Karasaki ◽  
Toyoko Ochiai ◽  
Yoshihiro Suzuki-Karasaki
Keyword(s):  
Cell Types ◽  
Channel Blockers ◽  
Organosulfur Compounds ◽  
Dependent Manner ◽  
Diallyl Trisulfide ◽  
Anticancer Effect ◽  
Anticancer Effects ◽  
Allium Vegetables ◽  
Ph Conditions

Allium vegetables such as garlic (Allium sativum L.) are rich in organosulfur compounds that prevent human chronic diseases, including cancer. Of these, diallyl trisulfide (DATS) exhibits anticancer effects against a variety of tumors, including malignant melanoma. Although previous studies have shown that DATS increases intracellular calcium (Ca2+) in different cancer cell types, the role of Ca2+ in the anticancer effect is obscure. In the present study, we investigated the Ca2+ pathways involved in the anti-melanoma effect. We used melittin, the bee venom that can activate a store-operated Ca2+ entry (SOCE) and apoptosis, as a reference. DATS increased apoptosis in human melanoma cell lines in a Ca2+-dependent manner. It also induced mitochondrial Ca2+ (Ca2+mit) overload through intracellular and extracellular Ca2+ fluxes independently of SOCE. Strikingly, acidification augmented Ca2+mit overload, and Ca2+ channel blockers reduced the effect more significantly under acidic pH conditions. On the contrary, acidification mitigated SOCE and Ca2+mit overload caused by melittin. Finally, Ca2+ channel blockers entirely inhibited the anti-melanoma effect of DATS. Our findings suggest that DATS explicitly evokes Ca2+mit overload via a non-SOCE, thereby displaying the anti-melanoma effect.

scholarly journals The lysosomal cathepsin protease CPL-1 plays a leading role in phagosomal degradation of apoptotic cells in Caenorhabditis elegans

2014 ◽  
Vol 25 (13) ◽  
pp. 2071-2083 ◽  
Author(s):  
Meng Xu ◽  
Yubing Liu ◽  
Liyuan Zhao ◽  
Qiwen Gan ◽  
Xiaochen Wang ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Apoptotic Cell ◽  
Cell Types ◽  
Apoptotic Cells ◽  
C Elegans ◽  
Lysosomal Protease ◽  
Leading Role ◽  
Lysosomal Proteases ◽  
Cell Corpse

During programmed cell death, the clearance of apoptotic cells is achieved by their phagocytosis and delivery to lysosomes for destruction in engulfing cells. However, the role of lysosomal proteases in cell corpse destruction is not understood. Here we report the identification of the lysosomal cathepsin CPL-1 as an indispensable protease for apoptotic cell removal in Caenorhabditis elegans. We find that loss of cpl-1 function leads to strong accumulation of germ cell corpses, which results from a failure in degradation rather than engulfment. CPL-1 is expressed in a variety of cell types, including engulfment cells, and its mutation does not affect the maturation of cell corpse–containing phagosomes, including phagosomal recruitment of maturation effectors and phagosome acidification. Of importance, we find that phagosomal recruitment and incorporation of CPL-1 occurs before digestion of cell corpses, which depends on factors required for phagolysosome formation. Using RNA interference, we further examine the role of other candidate lysosomal proteases in cell corpse clearance but find that they do not obviously affect this process. Collectively, these findings establish CPL-1 as the leading lysosomal protease required for elimination of apoptotic cells in C. elegans.

Cardiomyocyte apoptosis and ventricular remodeling after myocardial infarction in rats

2001 ◽  
Vol 280 (6) ◽  
pp. H2726-H2731 ◽  
Author(s):  
Eeva Palojoki ◽  
Antti Saraste ◽  
Anders Eriksson ◽  
Kari Pulkki ◽  
Markku Kallajoki ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Ejection Fraction ◽  
Ventricular Remodeling ◽  
Apoptotic Cell ◽  
Cell Loss ◽  
Left Ventricular ◽  
Cardiomyocyte Apoptosis ◽  
Border Zones ◽  
Terminal Deoxynucleotide Transferase

We investigated the role of cardiomyocyte apoptosis in the remodeling of the left ventricle from 24 h to 12 wk after myocardial infarction in the rat. Infarct size planimetry, quantification of cardiomyocyte apoptosis, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) methodology, and echocardiography (left ventricular diastolic diameter and ejection fraction) were performed. Sham-operated animals showed low rates of cardiomyocyte apoptosis (0.03%) and no change in diastolic diameter or ejection fraction during the study. Twenty-four hours after infarction, TUNEL positivity was high in the infarct areas (1.4%) and border zones (4.9%). It declined to 0.34% ( P < 0.01 vs. sham) at 4 wk and 0.10% at 12 wk in the border zones. In the remote myocardium, cardiomyocyte apoptosis increased to 0.07% ( P = 0.03 vs. sham) on day 1 and remained on the same level up to 4 wk. The increase in diastolic diameter 1–4 wk after infarction correlated ( r = 0.60, P < 0.01) with cardiomyocyte apoptosis in the noninfarcted myocardium, which quantitatively contributed most (>50%) to the apoptotic cell loss by 4 wk.

Caveolin-1 and caveolin-3 form heterooligomeric complexes in atrial cardiac myocytes that are required for doxorubicin-induced apoptosis

2008 ◽  
Vol 294 (1) ◽  
pp. H392-H401 ◽  
Author(s):  
Daniela Volonte ◽  
Charles F. McTiernan ◽  
Marek Drab ◽  
Michael Kasper ◽  
Ferruccio Galbiati
Keyword(s):  
Cardiac Myocytes ◽  
Functional Role ◽  
Cell Types ◽  
Structural Protein ◽  
Caveolin 1 ◽  
Protein Components ◽  
Induced Apoptosis ◽  
First Time ◽  
Rat Cardiac Myocytes

Caveolae are 50- to 100-nm invaginations of the plasma membrane. Caveolins are the structural protein components of caveolar membranes. The caveolin gene family is composed of three members: caveolin-1, caveolin-2, and caveolin-3. Caveolin-1 and caveolin-2 are coexpressed in many cell types, including adipocytes, endothelial cells, epithelial cells, and fibroblasts. In contrast, caveolin-3 expression is essentially restricted to skeletal and smooth muscle cells as well as cardiac myocytes. While the interaction between caveolin-1 and caveolin-2 has been documented previously, the reciprocal interaction between endogenous caveolin-1 and caveolin-3 and their functional role in cell types expressing both isoforms have yet to be identified. Here we demonstrate for the first time that caveolin-1 and caveolin-3 are coexpressed in mouse and rat cardiac myocytes of the atria but not ventricles. We also found that caveolin-1 and caveolin-3 can interact and form heterooligomeric complexes in this cell type. Doxorubicin is an effective anticancer agent, but its use is limited by the possible development of cardiotoxicity. Using caveolin-1- and caveolin-3-null mice, we show that both caveolin-1 and caveolin-3 expression are required for doxorubicin-induced apoptosis in the atria through activation of caspase 3. Together, these results bring new insight into the functional role of caveolae and suggest that caveolin-1/caveolin-3 heterooligomeric complexes may play a key role in chemotherapy-induced cardiotoxicity in the atria.

scholarly journals Inflammatory Bowel Disease and Risk of Colorectal Cancer: An Overview From Pathophysiology to Pharmacological Prevention

2021 ◽  
Vol 12 ◽  
Author(s):  
Marianna Lucafò ◽  
Debora Curci ◽  
Martina Franzin ◽  
Giuliana Decorti ◽  
Gabriele Stocco
Keyword(s):  
Colorectal Cancer ◽  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Inflammatory Process ◽  
Current Knowledge ◽  
Genetic Alterations ◽  
Pharmacological Prevention ◽  
Increased Risk ◽  
Inflammatory Bowel

Increased risk of colorectal cancer (CRC) in inflammatory bowel disease (IBD) patients has been attributed to long-standing chronic inflammation, with the contribution of genetic alterations and environmental factors such as the microbiota. Moreover, accumulating data indicate that IBD-associated CRC (IBD-CRC) may initiate and develop through a pathway of tumorigenesis distinct from that of sporadic CRC. This mini-review summarizes the current knowledge of IBD-CRC, focusing on the main mechanisms underlying its pathogenesis, and on the important role of immunomodulators and biologics used to treat IBD patients in interfering with the inflammatory process involved in carcinogenesis.

A Novel Sphingomyelin Synthase Gene, SMS1-Regulated Sphingomyelin/Ceramide-Rich Microdomain Plays a Crucial Role in Fas-Mediated Apoptosis.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1266-1266
Author(s):  
Michihiko Miyaji ◽  
Shohei Yamaoka ◽  
Jin Zhe Xiong ◽  
Ryuichi Amakawa ◽  
Tsuneyo Mimori ◽  
...  
Keyword(s):  
Cell Death ◽  
Crucial Role ◽  
Apoptotic Cell ◽  
Cholesterol Content ◽  
Sphingomyelin Synthase ◽  
Microscopy Analysis ◽  
Induced Apoptosis ◽  
Lipid Microdomain ◽  
First Time

Abstract Lipid microdomain consisting of sphingolipids, glycosphingolipids and cholesterol plays an important role in mediating cell death signals. Although functional analysis of lipid microdomain is conventionally performed by exclusion of cholesterol tightly binding with sphingomyein (SM), the exact role of SM in microdomain in signal transduction remains to be cleared. Since we for the first time obtained cDNA (SMS1) responsible for SM synthesis, it became possible to investigate the role of SM in the membrane without affecting cholesterol content. We here examine the role of SM/ceramide-rich microdomain in Fas-induced apoptosis using the SM-deficient cells and its revertant cells by transfection with SMS1. SM synthase-defective WR19L cells transfected with human-Fas gene (WR/Fas-SM(-)), and its functional revertant cells by transfection with SMS1 (WR/Fas-SMS1) were established. Both SMS1 cells and SM(-) cells expressed similar levels of CD44, CD90, CD95 (Human) and LFA-1 by FACS analysis. Although the levels of cholesterol and GM1-ganglioside on the surface of the membrane were similar in both cells, SM was detected only on the surface of SMS1 cells by FACS and confocal microscopy analysis. Fas crosslinking induced not only higher rate of apoptotic cell death, but also translocation of Fas into TritonX-100-insoluble fractions with a significant increase of ceramide in SMS1 cells as compared with SM(-) cells. After increase of SM and ceramide in microdomain, more efficient aggregation of Fas was detected with increase of DISC formation, resulting in activation of caspase-8 and 3 and decrease of mitochondrial membrane potential in SMS-1 cells than SM(-) cells. Our results clearly demonstrate that SM and ceramide in microdomain of plasma membrane plays a crucial role in Fas clustering and aggregation requires for activation of apoptosis-inducing signals.

Insufficient dietary choline aggravates disease severity in a mouse model of Citrobacter rodentium-induced colitis

2020 ◽  
Vol 125 (1) ◽  
pp. 50-61
Author(s):  
Tingting Ju ◽  
John P. Kennelly ◽  
René L. Jacobs ◽  
Benjamin P. Willing
Keyword(s):  
Gut Microbiota ◽  
Cell Loss ◽  
Amplicon Sequencing ◽  
Surface Epithelium ◽  
Rrna Gene ◽  
Citrobacter Rodentium ◽  
Minimal Impact ◽  
Inflammatory Bowel ◽  
Dietary Choline

AbstractDietary choline, which is converted to phosphatidylcholine (PC) in intestinal enterocytes, may benefit inflammatory bowel disease patients who typically have reduced intestinal choline and PC. The present study investigated the effect of dietary choline supplementation on colitis severity and intestinal mucosal homoeostasis using a Citrobacter rodentium-induced colitis model. C57BL/6J mice were fed three isoenergetic diets differing in choline level: choline-deficient (CD), choline-sufficient (CS) and choline-excess (CE) for 3 weeks prior to infection with C. rodentium. The effect of dietary choline levels on the gut microbiota was also characterised in the absence of infection using 16S rRNA gene amplicon sequencing. At 7 d following infection, the levels of C. rodentium in CD mice were significantly greater than that in CS or CE groups (P < 0·05). CD mice exhibited greater damage to the surface epithelium and goblet cell loss than the CS or CE mice, which was consistent with elevated pro-inflammatory cytokine and chemokine levels in the colon. In addition, CD group exhibited decreased concentrations of PC in the colon after C. rodentium infection, although the decrease was not observed in the absence of challenge. Select genera, including Allobaculum and Turicibacter, were enriched in response to dietary choline deficiency; however, there was minimal impact on the total bacterial abundance or the overall structure of the gut microbiota. Our results suggest that insufficient dietary choline intake aggravates the severity of colitis and demonstrates an essential role of choline in maintaining intestinal homoeostasis.

scholarly journals Role of TGF-Beta and Smad7 in Gut Inflammation, Fibrosis and Cancer

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 17
Author(s):  
Carmine Stolfi ◽  
Edoardo Troncone ◽  
Irene Marafini ◽  
Giovanni Monteleone
Keyword(s):  
Transforming Growth Factor ◽  
Cell Types ◽  
Mucosal Immune Response ◽  
The Body ◽  
Mucosal Cell ◽  
Gut Inflammation ◽  
Bowel Diseases ◽  
Inflammatory Bowel ◽  
Tgf Β1

The human gastrointestinal tract contains the largest population of immune cells in the body and this is a reflection of the fact that it is continuously exposed to a myriad of dietary and bacterial antigens. Although these cells produce a variety of inflammatory cytokines that could potentially promote tissue damage, in normal conditions the mucosal immune response is tightly controlled by counter-regulatory factors, which help induce and maintain gut homeostasis and tolerance. One such factor is transforming growth factor (TGF)-β1, a cytokine produced by multiple lineages of leukocytes, stromal cells and epithelial cells, and virtually targets all the gut mucosal cell types. Indeed, studies in animals and humans have shown that defects in TGF-β1 production and/or signaling can lead to the development of immune-inflammatory pathologies, fibrosis and cancer in the gut. Here, we review and discuss the available evidence about the role of TGF-β1 and Smad7, an inhibitor of TGF-β1 activity, in gut inflammation, fibrosis and cancer with particular regard to the contribution of these two molecules in the pathogenesis of inflammatory bowel diseases and colon cancer.

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