Downregulation of PIEZO2 in the Detrusor of Men With Bladder Outlet Obstruction and Its Association With Urinary Retention and Decreased Bladder Compliance.

PURPOSE: Recent research has highlighted the mechanotransducer PIEZO2 as a crucial factor in lower urinary tract function, demonstrating associations with bladder compliance (BC), bladder wall thickening, and elevated bladder pressure. We explored the hypothesis that PIEZO2 expression may be associated with lower urinary tract dysfunction in men with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH). METHODS: The study included a consecutive series of patients undergoing open prostatectomy for BPH at our hospital between September 2014 and January 2016. All participants underwent comprehensive preoperative evaluations, including urodynamic assessments. During prostatectomy, a full-thickness fragment of the bladder wall was obtained for subsequent PIEZO2 gene expression analysis. Cadaveric organ donors served as the control group. RESULTS: PIEZO2 expression was downregulated in the detrusor muscle of men with BPH compared to the control group. Among patients with BPH, those experiencing urinary retention and requiring an indwelling catheter exhibited significantly lower PIEZO2 messenger RNA (mRNA) expression than patients capable of spontaneous voiding. PIEZO2 mRNA expression was similar in men with and without detrusor overactivity. Additionally, a positive correlation was found between PIEZO2 mRNA expression levels and BC. CONCLUSION: Our findings indicate that PIEZO2 is downregulated in the detrusor muscle of men with BPH, particularly in those experiencing urinary retention and those with reduced BC. These results suggest a potential role for PIEZO2 in BOOinduced bladder dysfunction. Further research is required to clarify the role of PIEZO mechanotransducers in the bladder and to explore their therapeutic implications.

Identification and analgesic activity study of analgesic protein â ¦-2 from Naja naja atra venom.

Background: Acid-sensing ion channel 1a (ASIC1a) plays a critical role in physiological and pathological processes. To further elucidate the biological functions of ASICs and their relationships with disease occurrence and development, it is advantageous to investigate and develop additional regulatory factors for ASICs. Methods: In this study, cation exchange chromatography was used to separate seven chromatographic components from Naja naja atra venom. Capillary electrophoresis was employed to detect that Ⅶ peak component containing a main protein Ⅶ-2, which could bind to ASIC1a. The analgesic effects of Ⅶ-2 protein were determined using hot plate methods, and ASIC1a expression in spinal cord tissue from rats with inflammatory pain was detected using western blot. Results: The purified Ⅶ-2 protein named Naja naja atra venom-Ⅶ-2 (NNAV-Ⅶ-2) was obtained by Sephadex G-50 gel filtration, which exhibited a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a molecular weight of 6.7 kD. Remarkably, the NNAV-Ⅶ-2 protein demonstrated a significant analgesic effect and downregulated ASIC1a expression in the spinal cord tissue of rats with inflammatory pain. Conclusions: The analgesic mechanism of the NNAV-Ⅶ-2 protein may be associated with its binding to ASIC1a, consequently downregulating ASIC1a expression in neural tissues.

Vasorelaxant and tracheorelaxant effects of Bocconia arborea and their isolated benzophenanthridine alkaloids.

Bocconia arborea S. Watson (Papaveraceae) is an abundant medicinal plant in the North of Morelos State, Mexico, which is used for the treatment of several diseases. The aim of current investigation was to isolate the compounds responsible of the relaxant effect shown by the active extracts. Thus, phytochemical bio-guided fractionation allowed the isolation of angoline (1), dihydrosanguinarine (2), bocconarborine A (3), oxisanguinarine (4), and oxychelerithrine (5) from dichloromethanic and methanolic extracts from the bark of Bocconia arborea (Papaveraceae). The relaxant study on aortic and tracheal rat rings of all benzophenanthridines indicates that 1 was the most active compound of the entire series investigated. Angoline (1) induces its relaxant effect by a concentration-dependent manner through the calcium channel blockade in both tissues.

Exploring the interplay between extracellular pH and Dronedarone's pharmacological effects on cardiac function.

Dronedarone (DRN) is a clinically used drug to mitigate arrhythmias with multichannel block properties, including the sodium channel Nav1.5. Extracellular acidification is known to change the pharmacological properties of several antiarrhythmic drugs. Here, we explore how modification in extracellular pH (pHe) shapes the pharmacological profile of DRN upon Nav1.5 sodium current (INa) and in the ex vivo heart preparation. Embryonic human kidney cells (HEK293T/17) were used to transiently express the human isoform of Nav1.5 α-subunit. Patch-Clamp technique was employed to study INa. Neurotoxin-II (ATX-II) was used to induce the late sodium current (INaLate). Additionally, ex vivo Wistar male rat preparations in the Langendorff system were utilized to study electrocardiogram (ECG) waves. DRN preferentially binds to the closed state inactivation mode of Nav1.5 at pHe 7.0. The recovery from INa inactivation was delayed in the presence of DRN in both pHe 7.0 and 7.4, and the use-dependent properties were distinct at pHe 7.0 and 7.4. However, the potency of DRN upon the peak INa, the voltage dependence for activation, and the steady-state inactivation curves were not altered in both pHe tested. Also, the pHe did not change the ability of DRN to block INaLate. Lastly, DRN in a concentration and pH dependent manner modulated the QRS complex, QT and RR interval in clinically relevant concentration. Thus, the pharmacological properties of DRN upon Nav1.5 and ex vivo heart preparation partially depend on the pHe. The pHe changed the biological effect of DRN in the heart electrical function in relevant clinical concentration.

The Endocannabinoid Peptide RVD-Hemopressin Is a TRPV1 Channel Blocker.

Neurotransmission is critical for brain function, allowing neurons to communicate through neurotransmitters and neuropeptides. RVD-hemopressin (RVD-Hp), a novel peptide identified in noradrenergic neurons, modulates cannabinoid receptors CB1 and CB2. Unlike hemopressin (Hp), which induces anxiogenic behaviors via transient receptor potential vanilloid 1 (TRPV1) activation, RVD-Hp counteracts these effects, suggesting that it may block TRPV1. This study investigates RVD-Hp's role as a TRPV1 channel blocker using HEK293 cells expressing TRPV1-GFP. Calcium imaging and patch-clamp recordings demonstrated that RVD-Hp reduces TRPV1-mediated calcium influx and TRPV1 ion currents. Molecular docking and dynamics simulations indicated that RVD-Hp interacts with TRPV1's selectivity filter, forming stable hydrogen bonds and van der Waals contacts, thus preventing ion permeation. These findings highlight RVD-Hp's potential as a therapeutic agent for conditions involving TRPV1 activation, such as pain and anxiety.

Shelf-life of cooked meat of southern king crab (Lithodes santolla) and false king crab (Paralomis granulosa) during refrigerated storage.

Lithodes santolla (SKC) and Paralomis granulosa (FSKC) are economically important resources exploited in southern South America. The effect of refrigerated storage (4 °C on flake ice) on physico-chemical (pH, thiobarbituric reactive substances (TBARs), total volatile basic nitrogen (TVB-N), water holding capacity (WHC), and water content (WC)), microbiological (total viable mesophilic bacteria (TVMC), psychrotrophic bacteria (TVPC), Staphylococcus spp, coliforms, enterobacteria, molds and yeasts) and sensory (odor, appearance, texture, juiciness, and taste) parameters was analyzed in the cooked SKC and FSKC merus. For each species, cooked merus from 36 animals were randomly distributed into 6 groups, corresponding to 0, 2, 5, 8, 11, and 14 days of storage. On each day, samples were taken for physico-chemical (n = 6), microbiological (n = 3), and sensory (n = 15) analyses. The pH values increased over time (P < 0.01 in both species), the TBARs only increased in FSKC (P = 0.008), whereas the TVB-N significantly rose only in SKC (P = 0.001). The WHC and the WC did not change over time for any of the king crab species (P > 0.05) in all cases. The presence of TVCM, TVCP, and Staphylococcus spp. in both species was observed from day 0. Furthermore, pathogenic microorganisms (S. aureus, coliforms, and enterobacteria) were not detected, and only the TVCP in SFKC reached the suggested microbial limit after 11 days. All sensory scores significantly decreased (P < 0.001) over time, but the quality of both king crab species remained acceptable until the 11th day. These findings suggest that the shelf-life of cooked merus was 11 and 8 days for SKC and SFKC, respectively, when stored at 4 °C with the presence of flake ice. These contributions consist of elucidating the shelf-life of these economically important seafood products and providing insights into their quality maintenance during storage.

Trastornos del sueño en pacientes con fibrosis quística / Sleep disorders in patients with cystic fibrosis

Los trastornos del sueño son comunes en pacientes con fibrosis quística y afectan significativamente su calidad de vida. Estos pacientes experimentan una reducción en la calidad del sueño, hipoxemia nocturna, alteraciones en la polisomnografía y una alta prevalencia de síndrome de apneahipopnea obstructiva del sueño. Los factores que contribuyen a estas alteraciones incluyen la tos crónica, los síntomas digestivos, las rutinas de tratamiento y, posiblemente, la disfunción del canal CFTR. Sin embargo, el impacto de los moduladores de CFTR en la mejora de los trastornos del sueño aún no está claramente establecido, lo que resalta la necesidad de más estudios para comprender mejor su papel en el manejo del sueño en pacientes con fibrosis quística.

Sleep disorders are common in patients with cystic fibrosis and significantly affect their quality of life. These patients experience reduced sleep quality, nocturnal hypoxemia, polysomnography alterations, and a high prevalence of obstructive sleep apnea-hypopnea syndrome. Contributing factors include chronic cough, digestive symptoms, treatment routines, and potentially CFTR channel dysfunction. However, the impact of CFTR modulators on improving sleep disorders is not yet clearly established, highlighting the need for further studies to better understand their role in sleep management in cystic fibrosis patients.

The odyssey of the TR(i)P journey to the cellular membrane.

Ion channels are integral membrane proteins mediating ion flow in response to changes in their environment. Among the different types of ion channels reported to date, the super-family of TRP channels stands out since its members have been linked to many pathophysiological processes. The family comprises 6 subfamilies and 28 members in mammals, which are widely distributed throughout most tissues and organs and have an important role in several aspects of cellular physiology. It has been evidenced that abnormal expression, post-translational modifications, and channel trafficking are associated with several pathologies, such as cancer, cardiovascular disease, diabetes, and brain disorders, among others. In this review, we present an updated summary of the mechanisms involved in the subcellular trafficking of TRP channels, with a special emphasis on whether different post-translational modifications and naturally occurring mutagenesis affect both expression and trafficking. Additionally, we describe how such changes have been associated with the development and progress of diverse pathologies associated with the gain or loss of functional phenotypes. The study of these processes will not only contribute to a better understanding the role of TRP channels in the different tissues but will also present novel possible therapeutic targets in diseases where their activity is dysregulated.

Unlocking cellular traffic jams: olive oil-mediated rescue of CNG mutant channels.

One of the reasons to suggest olive oil consumption for a healthy life is its potential to induce robust lipidomic remodeling through membrane modification by dietary lipids. This remodeling might, in turn, modulate essential lipid-protein interactions while maintaining accurate transmembrane protein/domain orientation. Oleic acid, the primary compound in olive oil, has been suggested as a modulator of ion channel function. In this study, we explored whether this lipid could rescue the trafficking of mutated transmembrane proteins. In our initial approach, we supplemented the cell culture medium of HEK-293 cells expressing cyclic nucleotide channels tagged using green fluorescent protein (CNG-GFP) with olive oil or oleic acid. In addition to wild-type channels, we also expressed R272Q and R278W mutant channels, two non-functional intracellularly retained channels related to retinopathies. We used fluorescence microscopy and patch-clamp in the inside-out configuration to assess changes in the cell localization and function of the tested channels. Our results demonstrated that olive oil and oleic acid facilitated the transport of cyclic nucleotide-gated R272Q mutant channels towards the plasma membrane, rendering them electrophysiologically functional. Thus, our findings reveal a novel property of olive oil as a membrane protein traffic inductor.

Numerical study of the thermal performance of a single-channel cooling PV system using baffles and different nanofluids.

The present numerical study reports the performance of a cooling system for solar photovoltaic panels (PV) using different nanofluids (Al2O3, CuO, and ZnO). A novel parallel flow channel with strategically placed baffles was analyzed to improve the heat transfer between the back of PV and the nanofluid. The nanoparticles' Brownian motion and the nanofluid temperature effect were considered. Computational fluid dynamics was used to simulate the interaction between the fluid in motion and panel materials. Various nanoparticle concentrations, Reynolds numbers (18-1800), and solar radiation values (200-1000 W/m2) were examined. The results showed that the nanofluid composed of CuO was the most effective, improving thermal efficiency by 5.67 % compared to pure water in the lowest Re range. A 10 % vol. concentration of Al2O3 reduced temperature by up to 15 % and increased electrical efficiency by 4 % when the Re varied from 18 to 42. However, increasing the Re number and having low solar radiation values decreased the contribution of the nanofluid. Additionally, using baffles in the flow channel improved electrical efficiency by 2 %.

Blockade of CaV3 calcium channels and induction of G0/G1 cell cycle arrest in colon cancer cells by gossypol.

BACKGROUND AND PURPOSE: Gastrointestinal tumours overexpress voltage-gated calcium (CaV3) channels (CaV3.1, 3.2 and 3.3). CaV3 channels regulate cell growth and apoptosis colorectal cancer. Gossypol, a polyphenolic aldehyde found in the cotton plant, has anti-tumour properties and inhibits CaV3 currents. A systematic study was performed on gossypol blocking mechanism on CaV3 channels and its potential anticancer effects in colon cancer cells, which express CaV3 isoforms. EXPERIMENTAL APPROACH: Transcripts for CaV3 proteins were analysed in gastrointestinal cancers using public repositories and in human colorectal cancer cell lines HCT116, SW480 and SW620. The gossypol blocking mechanism on CaV3 channels was investigated by combining heterologous expression systems and patch-clamp experiments. The anti-tumoural properties of gossypol were estimated by cell proliferation, viability and cell cycle assays. Ca2+ dynamics were evaluated with cytosolic and endoplasmic reticulum (ER) Ca2+ indicators. KEY RESULTS: High levels of CaV3 transcripts correlate with poor prognosis in gastrointestinal cancers. Gossypol blockade of CaV3 isoforms is concentration- and use-dependent interacting with the closed, activated and inactivated conformations of CaV3 channels. Gossypol and CaV3 channels down-regulation inhibit colorectal cancer cell proliferation by arresting cell cycles at the G0/G1 and G2/M phases, respectively. CaV3 channels underlie the vectorial Ca2+ uptake by endoplasmic reticulum in colorectal cancer cells. CONCLUSION AND IMPLICATIONS: Gossypol differentially blocked CaV3 channel and its anticancer activity was correlated with high levels of CaV3.1 and CaV3.2 in colorectal cancer cells. The CaV3 regulates cell proliferation and Ca2+ dynamics in colorectal cancer cells. Understanding this blocking mechanism maybe improve cancer therapies.

Differential Regulation of Hemichannels and Gap Junction Channels by RhoA GTPase and Actin Cytoskeleton: A Comparative Analysis of Cx43 and Cx26.

Connexins (Cxs) are transmembrane proteins that assemble into gap junction channels (GJCs) and hemichannels (HCs). Previous researches support the involvement of Rho GTPases and actin microfilaments in the trafficking of Cxs, formation of GJCs plaques, and regulation of channel activity. Nonetheless, it remains uncertain whether distinct types of Cxs HCs and GJCs respond differently to Rho GTPases or changes in actin polymerization/depolymerization dynamics. Our investigation revealed that inhibiting RhoA, a small GTPase that controls actin polymerization, or disrupting actin microfilaments with cytochalasin B (Cyto-B), resulted in reduced GJCs plaque size at appositional membranes and increased transport of HCs to non-appositional plasma membrane regions. Notably, these effects were consistent across different Cx types, since Cx26 and Cx43 exhibited similar responses, despite having distinct trafficking routes to the plasma membrane. Functional assessments showed that RhoA inhibition and actin depolymerization decreased the activity of Cx43 GJCs while significantly increasing HC activity. However, the functional status of GJCs and HCs composed of Cx26 remained unaffected. These results support the hypothesis that RhoA, through its control of the actin cytoskeleton, facilitates the transport of HCs to appositional cell membranes for GJCs formation while simultaneously limiting the positioning of free HCs at non-appositional cell membranes, independently of Cx type. This dynamic regulation promotes intercellular communications and reduces non-selective plasma membrane permeability through a Cx-type dependent mechanism, whereby the activity of Cx43 HCs and GJCs are differentially affected but Cx26 channels remain unchanged.

Exploring Mixed Ionic-Electronic-Conducting PVA/PEDOT:PSS Hydrogels as Channel Materials for Organic Electrochemical Transistors.

Here, we report the preparation and evaluation of PVA/PEDOT:PSS-conducting hydrogels working as channel materials for OECT applications, focusing on the understanding of their charge transport and transfer properties. Our conducting hydrogels are based on crosslinked PVA with PEDOT:PSS interacting via hydrogen bonding and exhibit an excellent swelling ratio of ~180-200% w/w. Our electrochemical impedance studies indicate that the charge transport and transfer processes at the channel material based on conducting hydrogels are not trivial compared to conducting polymeric films. The most relevant feature is that the ionic transport through the swollen hydrogel is clearly different from the transport through the solution, and the charge transfer and diffusion processes govern the low-frequency regime. In addition, we have performed in operando Raman spectroscopy analyses in the OECT devices supported by first-principle computational simulations corroborating the doping/de-doping processes under different applied gate voltages. The maximum transconductance (gm~1.05 µS) and maximum volumetric capacitance (C*~2.3 F.cm-3) values indicate that these conducting hydrogels can be promising candidates as channel materials for OECT devices.

Probiotics and the reduction of SARS-CoV-2 infection through regulation of host cell calcium dynamics.

Calcium is a secondary messenger that interacts with several cellular proteins, regulates various physiological processes, and plays a role in diseases such as viral infections. Next-generation probiotics and live biotherapeutic products are linked to the regulation of intracellular calcium levels. Some viruses can manipulate calcium channels, pumps, and membrane receptors to alter calcium influx and promote virion production and release. In this study, we examined the use of bacteria for the prevention and treatment of viral diseases, such as coronavirus of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Vaccination programs have helped reduce disease severity; however, there is still a lack of well-recognized drug regimens for the clinical management of COVID-19. SARS-CoV-2 interacts with the host cell calcium (Ca2+), manipulates proteins, and disrupts Ca2+ homeostasis. This article explores how viruses exploit, create, or exacerbate calcium imbalances, and the potential role of probiotics in mitigating viral infections by modulating calcium signaling. Pharmacological strategies have been developed to prevent viral replication and block the calcium channels that serve as viral receptors. Alternatively, probiotics may interact with cellular calcium influx, such as Lactobacillus spp. The interaction between Akkermansia muciniphila and cellular calcium homeostasis is evident. A scientific basis for using probiotics to manipulate calcium channel activity needs to be established for the treatment and prevention of viral diseases while maintaining calcium homeostasis. In this review article, we discuss how intracellular calcium signaling can affect viral replication and explore the potential therapeutic benefits of probiotics.

Association of iPACK block and adductor canal block in dogs undergoing the tibial plateau leveling osteotomy technique: Report of 4 cases.

Orthopedic procedures are associated with severe postoperative pain. In TPLO, the block commonly used is the sciatic nerve block associated with the femoral nerve block. In orthopedic surgeries in human medicine, the iPACK block associated with the adductor canal block has been used as alternatives that do not affect the strength of the quadriceps femoris muscle. The objective of this study was to evaluate the trans and postoperative analgesic effect of the association of iPACK block and adductor canal block, as well as to evaluate the patient's motor recovery after surgery. Four patients were selected, without distinction of breed and gender, weighing more than 22lb, referred to TPLO. All patients underwent the combination of iPACK block and adductor canal block with 0.5% bupivacaine. The intraoperative evaluation was carried out by measuring mean arterial pressure, heart rate and respiratory rate, and all patients were stable during the procedure. The postoperative evaluation was carried out based on the assessment of pain using the modified Glasgow scale, in which all patients scored less than 05/24, and assessment of ambulation through videos using the adapted Muzzi scale, presenting ambulation between grade 1 and 2. No patient required intraoperative or postoperative analgesic rescue.

Os procedimentos ortopédicos estão associados a dores pós-operatórias severas. Em TPLO, o bloqueio comumente utilizado é o bloqueio do nervo ciático associado ao bloqueio do nervo femoral. Nas cirurgias ortopédicas em medicina humana, o bloqueio iPACK associado ao bloqueio do canal dos adutores tem sido utilizado como alternativa que não afeta a força do músculo quadríceps femoral. O objetivo deste estudo foi avaliar o efeito analgésico trans e pós-operatório da associação do bloqueio iPACK e bloqueio do canal adutor, bem como avaliar a recuperação motora do paciente após a cirurgia. Foram selecionados quatro pacientes, sem distinção de raça e sexo, com peso superior a 10kg, e encaminhados ao TPLO. Todos os pacientes foram submetidos a uma combinação de bloqueio iPACK e bloqueio do canal dos adutores com bupivacaína a 0,5%. A avaliação intraoperatória foi realizada através da aferição da pressão arterial média, frequência cardíaca e frequência respiratória, e todos os pacientes permaneceram estáveis durante o procedimento. A avaliação pós-operatória foi realizada com base na avaliação da dor pela escala de Glasgow modificada, na qual todos os pacientes pontuaram menos que 24/05, e avaliação da deambulação por meio de vídeos pela escala de Muzzi adaptada, mostrando deambulação entre grau 1 e 2. Nenhum paciente necessitou de resgate trans ou pós-operatório.

(S)-ML-SA1 Activates Autophagy via TRPML1-TFEB Pathway.

Autophagic flux plays a crucial role in various diseases. Recently, the lysosomal ion channel TRPML1 has emerged as a promising target in lysosomal storage diseases, such as mucolipidosis. The discovery of mucolipin synthetic agonist-1 (ML-SA1) has expanded our understanding of TRPML1's function and its potential therapeutic uses. However, ML-SA1 is a racemate with limited cellular potency and poor water solubility. In this study, we synthetized rac-ML-SA1, separated the enantiomers by chiral liquid chromatography and determined their absolute configuration by vibrational circular dichroism (VCD). In addition, we focused on investigating the impact of each enantiomer of ML-SA1 on the TRPML1-TFEB axis. Our findings revealed that (S)-ML-SA1 acts as an agonist for TRPML1 at the lysosomal membrane. This activation prompts transcription factor EB (TFEB) to translocate from the cytosol to the nucleus in a dose-dependent manner within live cells. Consequently, this signaling pathway enhances the expression of coordinated lysosomal expression and regulation (CLEAR) genes and activates autophagic flux. Our study presents evidence for the potential use of (S)-ML-SA1 in the development of new therapies for lysosomal storage diseases that target TRPML1.

Anti-Inflammatory Responses Produced with Nippostrongylus brasiliensis-Derived Uridine via the Mitochondrial ATP-Sensitive Potassium Channel and Its Anti-Atherosclerosis Effect in an Apolipoprotein E Gene Knockout Mouse Model.

Atherosclerosis (AS) has become the leading cause of cardiovascular disease worldwide. Our previous study had observed that Nippostrongylus brasiliensis (Nb) infection or its derived products could inhibit AS development by inducing an anti-inflammatory response. We performed a metabolic analysis to screen Nb-derived metabolites with anti-inflammation activity and evaluated the AS-prevention effect. We observed that the metabolite uridine had higher expression levels in mice infected with the Nb and ES (excretory-secretory) products and could be selected as a key metabolite. ES and uridine interventions could reduce the pro-inflammatory responses and increase the anti-inflammatory responses in vitro and in vivo. The apolipoprotein E gene knockout (ApoE-/-) mice were fed with a high-fat diet for the AS modeling. Following the in vivo intervention, ES products or uridine significantly reduced serum and liver lipid levels, alleviated the formation of atherosclerosis, and reduced the pro-inflammatory responses in serum or plaques, while the anti-inflammatory responses showed opposite trends. After blocking with 5-HD (5-hydroxydecanoate sodium) in vitro, the mRNA levels of M2 markers were significantly reduced. When blocked with 5-HD in vivo, the degree of atherosclerosis was worsened, the pro-inflammatory responses were increased compared to the uridine group, while the anti-inflammatory responses decreased accordingly. Uridine, a key metabolite from Nippostrongylus brasiliensis, showed anti-inflammatory and anti-atherosclerotic effects in vitro and in vivo, which depend on the activation of the mitochondrial ATP-sensitive potassium channel.

TRPC5 channel participates in myocardial injury in chronic intermittent hypoxia.

OBJECTIVE: The purpose of this study is to develop an animal model of Chronic Intermittent Hypoxia (CIH) and investigate the role of the TRPC5 channel in cardiac damage in OSAHS rats. METHODS: Twelve male Sprague Dawley rats were randomly divided into the CIH group and the Normoxic Control (NC) group. Changes in structure, function, and pathology of heart tissue were observed through echocardiography, transmission electron microscopy, HE-staining, and TUNEL staining. RESULTS: The Interventricular Septum thickness at diastole (IVSd) and End-Diastolic Volume (EDV) of rats in the CIH group significantly increased, whereas the LV ejection fraction and LV fraction shortening significantly decreased. TEM showed that the myofilaments in the CIH group were loosely arranged, the sarcomere length varied, the cell matrix dissolved, the mitochondrial cristae were partly flocculent, the mitochondrial outer membrane dissolved and disappeared, and some mitochondria were swollen and vacuolated. The histopathological examination showed that the cardiomyocytes in the CIH group were swollen with granular degeneration, some of the myocardial fibers were broken and disorganized, and most of the nuclei were vacuolar and hypochromic. CONCLUSION: CIH promoted oxidative stress, the influx of Ca2+, and the activation of the CaN/NFATc signaling pathway, which led to pathological changes in the morphology and ultrastructure of cardiomyocytes, the increase of myocardial apoptosis, and the decrease of myocardial contractility. These changes may be associated with the upregulation of TRPC5.

NCS-1 protein regulates TRPA1 channel through the PI3K pathway in breast cancer and neuronal cells.

The physical and functional interaction between transient receptor potential channel ankyrin 1 (TRPA1) and neuronal calcium sensor 1 (NCS-1) was assessed. NCS-1 is a calcium (Ca2+) sensor found in many tissues, primarily neurons, and TRPA1 is a Ca2+ channel involved not only in thermal and pain sensation but also in conditions such as cancer and chemotherapy-induced peripheral neuropathy, in which NCS-1 is also a regulatory component.We explored the interactions between these two proteins by employing western blot, qRT-PCR, co-immunoprecipitation, Ca2+ transient monitoring with Fura-2 spectrophotometry, and electrophysiology assays in breast cancer cells (MDA-MB-231) with different levels of NCS-1 expression and neuroblastoma cells (SH-SY5Y).Our findings showed that the expression of TRPA1 was directly correlated with NCS-1 levels at both the protein and mRNA levels. Additionally, we found a physical and functional association between these two proteins. Physically, the NCS-1 and TRPA1 co-immunoprecipitate. Functionally, NCS-1 enhanced TRPA1-dependent Ca2+ influx, current density, open probability, and conductance, where the functional effects depended on PI3K. Conclusion: NCS-1 appears to act not only as a Ca2+ sensor but also modulates TRPA1 protein expression and channel function in a direct fashion through the PI3K pathway. These results contribute to understanding how Ca2+ homeostasis is regulated and provides a mechanism underlying conditions where Ca2+ dynamics are compromised, including breast cancer. With a cellular pathway identified, targeted treatments can be developed for breast cancer and neuropathy, among other related diseases.

Extracellular acidification reveals the antiarrhythmic properties of amiodarone related to late sodium current-induced atrial arrhythmia.

BACKGROUND: Amiodarone (AMIO) is an antiarrhythmic drug with the pKa in the physiological range. Here, we explored how mild extracellular pH (pHe) changes shape the interaction of AMIO with atrial tissue and impact its pharmacological properties in the classical model of sea anemone sodium channel neurotoxin type 2 (ATX) induced late sodium current (INa-Late) and arrhythmias. METHOD: Isolated atrial cardiomyocytes from male Wistar rats and human embryonic kidney cells expressing SCN5A Na+ channels were used for patch-clamp experiments. Isolated right atria (RA) and left atria (LA) tissue were used for bath organ experiments. RESULTS: A more acidophilic pHe caused negative inotropic effects on isolated RA and LA atrial tissue, without modification of the pharmacological properties of AMIO. A pHe of 7.0 changed the sodium current (INa) related components of the action potential (AP), which was enhanced in the presence of AMIO. ATXinduced arrhythmias in isolated RA and LA. Also, ATX prolonged the AP duration and enhanced repolarization dispersion in isolated cardiomyocytes in both pHe 7.4 and pHe 7.0. Pre-incubation of the isolated RA and LA and isolated atrial cardiomyocytes with AMIO prevented arrhythmias induced by ATX only at a pHe of 7.0. Moreover, AMIO was able to block INa-Late induced by ATX only at a pHe of 7.0. CONCLUSION: The pharmacological properties of AMIO concerning healthy rat atrial tissue are not dependent on pHe. However, the prevention of arrhythmias induced by INa-Late is pHe-dependent. The development of drugs analogous to AMIO with charge stabilization may help to create more effective drugs to treat arrhythmias related to the INa-Late.