scholarly journals Genetic background influences expression and function of the cation channel TRPM4 in the mouse heart

2020 ◽  
Vol 115 (6) ◽  
Author(s):  
Rebekka Medert ◽  
Andy Pironet ◽  
Lucas Bacmeister ◽  
Sebastian Segin ◽  
Juan E. Camacho Londoño ◽  
...  
Keyword(s):  
Genetic Background ◽  
Transient Receptor Potential ◽  
Cardiac Contractility ◽  
Receptor Potential ◽  
Disease Status ◽  
Mouse Strains ◽  
Mouse Heart ◽  
Transient Receptor Potential Melastatin ◽  
Different Genetic Background

AbstractTransient receptor potential melastatin 4 (TRPM4) cation channels act in cardiomyocytes as a negative modulator of the L-type Ca2+ current. Ubiquitous Trpm4 deletion in mice leads to an increased β-adrenergic inotropy in healthy mice as well as after myocardial infarction. In this study, we set out to investigate cardiac inotropy in mice with cardiomyocyte-specific Trpm4 deletion. The results guided us to investigate the relevance of TRPM4 for catecholamine-evoked Ca2+ signaling in cardiomyocytes and inotropy in vivo in TRPM4-deficient mouse models of different genetic background. Cardiac hemodynamics were investigated using pressure–volume analysis. Surprisingly, an increased β-adrenergic inotropy was observed in global TRPM4-deficient mice on a 129SvJ genetic background, but the inotropic response was unaltered in mice with global and cardiomyocyte-specific TRPM4 deletion on the C57Bl/6N background. We found that the expression of TRPM4 proteins is about 78 ± 10% higher in wild-type mice on the 129SvJ versus C57Bl/6N background. In accordance with contractility measurements, our analysis of the intracellular Ca2+ transients revealed an increase in ISO-evoked Ca2+ rise in Trpm4-deficient cardiomyocytes of the 129SvJ strain, but not of the C57Bl/6N strain. No significant differences were observed between the two mouse strains in the expression of other regulators of cardiomyocyte Ca2+ homeostasis. We conclude that the relevance of TRPM4 for cardiac contractility depends on homeostatic TRPM4 expression levels or the genetic endowment in different mouse strains as well as on the health/disease status. Therefore, the concept of inhibiting TRPM4 channels to improve cardiac contractility needs to be carefully explored in specific strains and species and prospectively in different genetically diverse populations of patients.

scholarly journals Chemosensitization of doxorubicin against lung cancer by nature borneol, involvement of TRPM8-regulated calcium mobilization

2020 ◽  
Author(s):  
Haoqiang Lai ◽  
Chang Liu ◽  
Wenwei Lin ◽  
tf Chen ◽  
An Hong
Keyword(s):  
Lung Cancer ◽  
Therapeutic Target ◽  
Transient Receptor Potential ◽  
A549 Cells ◽  
Receptor Potential ◽  
Calcium Mobilization ◽  
Ros Generation ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor

Abstract Background Lung cancer possesses high mortality rate and tolerances to multiple chemotherapeutics. Natural Borneol (NB) is a monoterpenoid compound that found to facilitate the bioavailability of drugs. In this study, we attempted to investigate effects of NB on the chemosensitivity in A549 cells and try to elucidate its therapeutic target. Methods The effects of NB on chemosensitivity in A549 cells was examined by MTT assay. The mechanism studies were evaluated by flow cytometry and western blotting assay. Surface plasmon resonance (SPR) and LC-MS combined analysis (MS-SPRi) was performed to elucidate the candidate target of NB contributes to this synergism. The chemosensitizing capacity of NB in vivo was conducted in nude mice bearing A549 tumors. Results NB pretreatment sensitizes A549 cells to low dosage of DOX, leading to a 15.7% to 41.5% increase in apoptosis, which is corelated with ERK and AKT inactivation but activation of phosphor-p38MAPK, -JNK and p53. Furthermore, this synergism depends on reactive oxygen species (ROS) generation. The MS-SPRi analysis reveals that the transient receptor potential melastatin-8 (TRPM8) is the interaction target of NB in potentiating DOX killing potency. Genetically knock down of TRPM8 significantly suppress the chemosensitizing effects of NB with the involvement of inhibiting ROS generation through restraining calcium mobilization. Moreover, pretreatment of NB synergistically enhanced the anticancer effects of DOX to delay tumor progression in vivo. Conclusions These results suggest that TRPM8 may be a valid therapeutic target in the potential application of NB serves as a chemosensitizer for lung cancer treatment.

scholarly journals A Role for H2O2 and TRPM2 in the Induction of Cell Death: Studies in KGN Cells

Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 518 ◽  
Author(s):  
Carsten Theo Hack ◽  
Theresa Buck ◽  
Konstantin Bagnjuk ◽  
Katja Eubler ◽  
Lars Kunz ◽  
...  
Keyword(s):  
Cell Death ◽  
Transient Receptor Potential ◽  
Therapeutic Potential ◽  
Apoptotic Cell ◽  
Receptor Potential ◽  
Granulosa Cell Tumor ◽  
Nadph Oxidase 4 ◽  
Transient Receptor Potential Melastatin ◽  
Trpm2 Channel

Recent studies showed that KGN cells, derived from a human granulosa cell tumor (GCT), express NADPH oxidase 4 (NOX4), an important source of H2O2. Transient receptor potential melastatin 2 (TRPM2) channel is a Ca2+ permeable cation channel that can be activated by H2O2 and plays an important role in cellular functions. It is also able to promote susceptibility to cell death. We studied expression and functionality of TRPM2 in KGN cells and examined GCT tissue microarrays (TMAs) to explore in vivo relevance. We employed live cell, calcium and mitochondrial imaging, viability assays, fluorescence activated cell sorting (FACS) analysis, Western blotting and immunohistochemistry. We confirmed that KGN cells produce H2O2 and found that they express functional TRPM2. H2O2 increased intracellular Ca2+ levels and N-(p-Amylcinnamoyl)anthranilic acid (ACA), a TRPM2 inhibitor, blocked this action. H2O2 caused mitochondrial fragmentation and apoptotic cell death, which could be attenuated by a scavenger (Trolox). Immunohistochemistry showed parallel expression of NOX4 and TRPM2 in all 73 tumor samples examined. The results suggest that GCTs can be endowed with a system that may convey susceptibility to cell death. If so, induction of oxidative stress may be beneficial in GCT therapy. Our results also imply a therapeutic potential for TRPM2 as a drug target in GCTs.

scholarly journals Deletion of Trpm4 alters the function and expression of NaV1.5 channel in murine cardiac myocytes

2020 ◽  
Author(s):  
Ozhathil Lijo Cherian ◽  
Jean-Sébastien Rougier ◽  
Prakash Arullampalam ◽  
Maria C. Essers ◽  
Hugues Abriel
Keyword(s):  
Cardiac Myocytes ◽  
Transient Receptor Potential ◽  
Conduction Block ◽  
Receptor Potential ◽  
Intraventricular Conduction ◽  
Cardiac Electrical Activity ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor ◽  
And Function

AbstractTransient receptor potential melastatin member 4 (TRPM4) encodes a Ca+ -activated non-selective cation channel that is functionally expressed in several tissues including the heart. Pathogenic mutants in TRPM4 have been reported in patients with inherited cardiac diseases including conduction block and Brugada syndrome. Heterologous expression of mutant channels in cell lines indicates that these mutations can lead to an increase or decrease in TRPM4 expression and function at the cell surface. While the expression and clinical variant studies further stress the importance of TRPM4 in cardiac function, the cardiac electrophysiological phenotypes in Trpm4 knockdown mouse models remain incompletely characterized. To study the functional consequences of Trpm4 deletion on cardiac electrical activity in mice, we performed perforated-patch clamp and immunohistochemistry studies on isolated atrial and ventricular cardiac myocytes and surface, pseudo and intracardiac ECGs either in vivo or on Langendorff-perfused explanted mouse hearts. We observed that Trpm4 is expressed in atrial and ventricular cardiac myocytes and that deletion of Trpm4 unexpectedly reduces the peak Na+ currents in the myocytes. Hearts from Trpm4-/- mice presented increased sensitivity towards mexiletine, a Na+ channel blocker, and slower intraventricular conduction, consistent with the reduction of peak Na+ current observed in the isolated cardiac myocytes. This reduction in Na+ current is explained by the observed decrease in protein expression of NaV1.5 in Trpm4-/- mice. This study suggests that Trpm4 expression impacts Na+ current in murine cardiac myocytes and points towards a novel function of Trpm4 regulating the NaV1.5 expression in murine cardiac myocytes.

scholarly journals Development of an AAV9-RNAi-mediated silencing strategy to abrogate TRPM4 expression in the adult heart

2021 ◽  
Author(s):  
Rebekka Medert ◽  
Andreas Jungmann ◽  
Staffan Hildebrand ◽  
Martin Busch ◽  
Dirk Grimm ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Cardiac Contractility ◽  
Cation Channel ◽  
Expression Cassette ◽  
Mouse Heart ◽  
High Concentration ◽  
Tail Vein ◽  
Promising Strategy ◽  
Transient Receptor Potential Melastatin ◽  
Virus Serotype

AbstractThe cation channel transient receptor potential melastatin 4 (TRPM4) is a calcium-activated non-selective cation channel and acts in cardiomyocytes as a negative modulator of the L-type Ca2+ influx. Global deletion of TRPM4 in the mouse led to increased cardiac contractility under β-adrenergic stimulation. Consequently, cardiomyocyte-specific inactivation of the TRPM4 function appears to be a promising strategy to improve cardiac contractility in heart failure patients. The aim of this study was to develop a gene therapy approach in mice that specifically silences the expression of TRPM4 in cardiomyocytes. First, short hairpin RNAmiR30 (shRNAmiR30) sequences against the TRPM4 mRNA were screened in vitro using lentiviral transduction for a stable expression of the shRNA cassettes. Western blot analysis identified three efficient shRNAmiR30 sequences out of six, which reduced the endogenous TRPM4 protein level by up to 90 ± 6%. Subsequently, the most efficient shRNAmiR30 sequences were delivered into cardiomyocytes of adult mice using adeno-associated virus serotype 9 (AAV9)-mediated gene transfer. Initially, the AAV9 vector particles were administered via the lateral tail vein, which resulted in a downregulation of TRPM4 by 46 ± 2%. Next, various optimization steps were carried out to improve knockdown efficiency in vivo. First, the design of the expression cassette was streamlined for integration in a self-complementary AAV vector backbone for a faster expression. Compared to the application via the lateral tail vein, intravenous application via the retro-orbital sinus has the advantage that the vector solution reaches the heart directly and in a high concentration, and eventually a TRPM4 knockdown efficiency of 90 ± 7% in the heart was accomplished by this approach. By optimization of the shRNAmiR30 constructs and expression cassette as well as the route of AAV9 vector application, a 90% reduction of TRPM4 expression was achieved in the adult mouse heart. In the future, AAV9-RNAi-mediated inactivation of TRPM4 could be a promising strategy to increase cardiac contractility in preclinical animal models of acute and chronic forms of cardiac contractile failure.

scholarly journals trpm7 Regulation of in Vivo Cation Homeostasis and Kidney Function Involves Stanniocalcin 1 and fgf23

Endocrinology ◽  
2010 ◽  
Vol 151 (12) ◽  
pp. 5700-5709 ◽  
Author(s):  
Michael R. Elizondo ◽  
Erine H. Budi ◽  
David M. Parichy
Keyword(s):  
Kidney Function ◽  
Transient Receptor Potential ◽  
Stone Formation ◽  
Fibroblast Growth Factor 23 ◽  
Receptor Potential ◽  
Larval Stages ◽  
Transient Receptor Potential Melastatin ◽  
Cation Homeostasis

The transient receptor potential melastatin 7 (trpm7) channel kinase is a primary regulator of magnesium homeostasis in vitro. Here we show that trpm7 is an important regulator of cation homeostasis as well as kidney function in vivo. Using zebrafish trpm7 mutants, we show that early larvae exhibit reduced levels of both total magnesium and total calcium. Accompanying these deficits, we show that trpm7 mutants express higher levels of stanniocalcin 1 (stc1), a potent regulator of calcium homeostasis. Using transgenic overexpression and morpholino oligonucleotide knockdown, we demonstrate that stc1 modulates both calcium and magnesium levels in trpm7 mutants and in the wild type and that levels of these cations are restored to normal in trpm7 mutants when stc1 activity is blocked. Consistent with defects in both calcium and phosphate homeostasis, we further show that trpm7 mutants develop kidney stones by early larval stages and exhibit increased levels of the anti-hyperphosphatemic factor, fibroblast growth factor 23 (fgf23). Finally, we demonstrate that elevated fgf23 expression contributes to kidney stone formation by morpholino knockdown of fgf23 in trpm7 mutants. Together, these analyses reveal roles for trpm7 in regulating cation homeostasis and kidney function in vivo and implicate both stc1 and fgf23 in these processes.

Abstract 171: Plasma Hypoosmolarity After Birth Promotes Closure of the Ductus Arteriosus

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Rika Aoki ◽  
Utako Yokoyama ◽  
Yasuhiro Ichikawa ◽  
Shun Kumagaya ◽  
Shiho Iwasaki ◽  
...  
Keyword(s):  
Cord Blood ◽  
Preterm Infants ◽  
Transient Receptor Potential ◽  
Freezing Point ◽  
Ductus Arteriosus ◽  
Receptor Potential ◽  
Whole Body ◽  
Plasma Osmolarity ◽  
Transient Receptor Potential Melastatin

Background: Changes in environmental conditions after birth, such as increased oxygen tension, are known to regulate the closure of the ductus arteriosus (DA). We previously found that plasma osmolarity was significantly decreased early after birth in rats, and that Transient Receptor Potential Melastatin (TRPM) 3, a hypoosmolarity sensor, was highly expressed in the rat DA compared to the aorta. We assessed the hypothesis that plasma hypoosmolarity regulated tension of the DA via TRPM3. Methods: Fura-2 assay was used to evaluate the change in intracellular calcium [Ca 2+ ] i in vascular smooth muscle cells (SMCs). Tension of vascular rings was measured by a wire myograph system. Rapid whole-body freezing method was used to examine vasoconstriction in rat in vivo . Plasma osmolarity of human preterm infants was analyzed by freezing point depression osmometry. Results: We found that [Ca 2+ ] i was increased by hypoosmolarity (270mOsm/kg) in SMCs isolated from the rat DA (DASMCs) compared to aortic SMCs (31.3% vs. 8.5% of basal 340/390 ratio P <0.01, n=6). When DASMCs were treated with siTRPM3, hypoosmolarity-induced [Ca 2+ ] i elevation was attenuated by 48.7% ( P <0.01, n=6). Hypoosmolarity (270 and 250mOsm/kg) increased the tension of rat DA (17.4% and 29.8% of 120mM of KCl, respectively, P <0.01, n=8). Moreover, a TRPM3 activator pregnenolone sulfate (200μ M) induced contraction of the rat DA (39.4% of KCl P <0.001, n=6). Conversely, when plasma osmolarity was kept higher to 322mOsm/kg by intra-peritoneal injection of 5.4% hypersaline, the DA closure was partially inhibited by 13% compared to 0.9% saline injection in vivo ( P <0.05, n=11). Plasma osmolarity was decreased 2 h after birth in late preterm infants (28-35weeks’ gestation) (3.2±0.8 % reduction of cord blood, P <0.001, n=35), but not in early preterm infants (24-27weeks’ gestation) (1.1±1.3 % reduction of cord blood, NS , n=17). Furthermore, plasma osmolarity of patent DA (PDA) patients recovered to the adult level by the 2nd day of life while it still remained low in non PDA patients. Conclusions: These results suggest that plasma hypoosmolarity after birth promotes DA closure via TRPM3 and that keeping the plasma osmolarity within proper levels during early neonatal period would be important for DA closure.

scholarly journals Knockdown of TRPM7 prevents tumor growth, migration, and invasion through the Src, Akt, and JNK pathway in bladder cancer

BMC Urology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Eun Hye Lee ◽  
So Young Chun ◽  
Bomi Kim ◽  
Bo Hyun Yoon ◽  
Jun Nyung Lee ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Transient Receptor Potential ◽  
Xenograft Model ◽  
Signal Transduction Pathway ◽  
Receptor Potential ◽  
Immunoblot Analysis ◽  
Migration And Invasion ◽  
Jnk Pathway ◽  
Transient Receptor Potential Melastatin

Abstract Background Bladder cancer (BC) is one of the most common malignancies of the urinary tract. The role of transient receptor potential melastatin 7 (TRPM7) in BC remains unclear. The aim of this study was to investigate the function and signal transduction pathway of TRPM7 in BC. Methods T24 and UMUC3 cells were used to evaluate the molecular mechanism of TRPM7 by immunoblot analysis. Small interfering RNA was used to knockdown TRPM7, and the effect of silencing TRPM7 was studied by wound healing, migration, and invasion assays in T24 and UMUC3 cells. Xenograft model study was obtained to analyze the effect of TRPM7 inhibition in vivo. Results Silencing of TRPM7 decreased the migration and invasion ability of T24 and UMUC3 cells. The phosphorylation of Src, Akt, and JNK (c-Jun N-terminal kinase) was also suppressed by TRPM7 silencing. Src, Akt, and JNK inhibitors effectively inhibited the migration and invasion of T24 and UMUC3 cells. In addition, the TRPM7 inhibitor, carvacrol, limited the tumor size in a xenograft model. Conclusion Our data reveal that TRPM7 regulates the migration and invasion of T24 and UMUC3 cells via the Src, Akt, and JNK signaling pathway. Therefore, TRPM7 suppression could be a potential treatment for BC patients.

scholarly journals Mechanisms of Cancer Inhibition by Local Anesthetics

2021 ◽  
Vol 12 ◽  
Author(s):  
Yiguo Zhang ◽  
Yixin Jing ◽  
Rui Pan ◽  
Ke Ding ◽  
Rong Chen ◽  
...  
Keyword(s):  
Local Anesthetics ◽  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Growth Factor Receptor ◽  
Cancer Recurrence ◽  
Receptor Potential ◽  
Perioperative Analgesia ◽  
Transient Receptor Potential Melastatin

The use of local anesthetics during surgical treatment of cancer patients is an important part of perioperative analgesia. In recent years, it has been showed that local anesthetics can directly or indirectly affect the progression of tumors. In vitro and in vivo studies have demonstrated that local anesthetics reduced cancer recurrence. The etiology of this effect is likely multifactorial. Numerous mechanisms were proposed based on the local anesthetic used and the type of cancer. Mechanisms center on NaV1.5 channels, Ras homolog gene family member A, cell cycle, endothelial growth factor receptor, calcium Influx, microRNA and mitochondrial, in combination with hyperthermia and transient receptor potential melastatin 7 channels. Local anesthetics significantly decrease the proliferation of cancers, including ovarian, breast, prostate, thyroid, colon, glioma, and histiocytic lymphoma cell cancers, by activating cell death signaling and decreasing survival pathways. We also summarized clinical evidence and randomized trial data to confirm that local anesthetics inhibited tumor progression.

scholarly journals Deletion of Trpm4 Alters the Function of the Nav1.5 Channel in Murine Cardiac Myocytes

2021 ◽  
Vol 22 (7) ◽  
pp. 3401
Author(s):  
Lijo Cherian Ozhathil ◽  
Jean-Sébastien Rougier ◽  
Prakash Arullampalam ◽  
Maria C. Essers ◽  
Daniela Ross-Kaschitza ◽  
...  
Keyword(s):  
Cardiac Myocytes ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Na Channel ◽  
Na Current ◽  
Intraventricular Conduction ◽  
Cardiac Electrical Activity ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor

Transient receptor potential melastatin member 4 (TRPM4) encodes a Ca2+-activated, non-selective cation channel that is functionally expressed in several tissues, including the heart. Pathogenic mutants in TRPM4 have been reported in patients with inherited cardiac diseases, including conduction blockage and Brugada syndrome. Heterologous expression of mutant channels in cell lines indicates that these mutations can lead to an increase or decrease in TRPM4 expression and function at the cell surface. While the expression and clinical variant studies further stress the importance of TRPM4 in cardiac function, the cardiac electrophysiological phenotypes in Trpm4 knockdown mouse models remain incompletely characterized. To study the functional consequences of Trpm4 deletion on cardiac electrical activity in mice, we performed perforated-patch clamp and immunoblotting studies on isolated atrial and ventricular cardiac myocytes and surfaces, as well as on pseudo- and intracardiac ECGs, either in vivo or in Langendorff-perfused explanted mouse hearts. We observed that TRPM4 is expressed in atrial and ventricular cardiac myocytes and that deletion of Trpm4 unexpectedly reduces the peak Na+ currents in myocytes. Hearts from Trpm4−/− mice presented increased sensitivity towards mexiletine, a Na+ channel blocker, and slower intraventricular conduction, consistent with the reduction of the peak Na+ current observed in the isolated cardiac myocytes. This study suggests that TRPM4 expression impacts the Na+ current in murine cardiac myocytes and points towards a novel function of TRPM4 regulating the Nav1.5 function in murine cardiac myocytes.

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