Korean Journal of Physiology & Pharmacology最新文献

The TRPM4 gene encodes a Ca²⁺-activated monovalent cation channel called transient receptor potential melastatin 4 (TRPM4) that is expressed in various tissues. Dysregulation or abnormal expression of TRPM4 has been linked to a range of diseases. We introduced the hemagglutinin (HA) tag into the extracellular S6 loop of TRPM4, resulting in an HA-tagged version called TRPM4-HA. This TRPM4-HA was developed to investigate the purification, localization, and function of TRPM4 in different physiological and pathological conditions. TRPM4-HA was successfully expressed in the intact cell membrane and exhibited similar electrophysiological properties, such as the current-voltage relationship, rapid desensitization, and current size, compared to the wild-type TRPM4. The presence of the TRPM4 inhibitor 9-phenanthrol did not affect these properties. Furthermore, a wound-healing assay showed that TRPM4-HA induced cell proliferation and migration, similar to the native TRPM4. Co-expression of protein tyrosine phosphatase, non-receptor type 6 (PTPN6 or SHP-1) with TRPM4-HA led to the translocation of TRPM4-HA to the cytosol. To investigate the interaction between PTPN6 and tyrosine residues of TRPM4 in enhancing channel activity, we generated four mutants in which tyrosine (Y) residues were substituted with phenylalanine (F) at the N-terminus of TRPM4. The YF mutants displayed properties and functions similar to TRPM4-HA, except for the Y256F mutant, which showed resistance to 9-phenanthrol, suggesting that Y256 may be involved in the binding site for 9-phenanthrol. Overall, the creation of HA-tagged TRPM4 provides researchers with a valuable tool to study the role of TRPM4 in different conditions and its potential interactions with other proteins, such as PTPN6.

Complex diseases including cardiovascular disease are caused by a combination of the alternation of many genes and the influence of environments. Recently, non-coding RNAs (ncRNAs) have been shown to be involved in diverse diseases, and the functions of various ncRNAs have been reported. Many researchers have elucidated the mechanisms of action of these ncRNAs at the cellular level prior to in vivo and clinical studies of the diseases. Due to the characteristics of complex diseases involving intercellular crosstalk, it is important to study communication between multiple cells. However, there is a lack of literature summarizing and discussing studies of ncRNAs involved in intercellular crosstalk in cardiovascular diseases. Therefore, this review summarizes recent discoveries in the functional mechanisms of intercellular crosstalk involving ncRNAs, including microRNAs, long non-coding RNAs, and circular RNAs. In addition, the pathophysiological role of ncRNAs in this communication is extensively discussed in various cardiovascular diseases.

Crohn's disease (CD) is a chronic inflammatory illness of the digestive system with unknown etiology, and its incidence is increasing worldwide. However, there are currently no effective treatments or medications available for individuals with CD. Therefore, novel therapeutic strategies are urgently needed. The bioactive compounds and targets associated with compounds of Qinghua Xiaoyong Formula (QHXYF) were examined using The Traditional Chinese Medicine Systems Pharmacology database, and 5 disease target databases were also used to identify CD-related disease targets. A total of 166 overlapping targets were identified from QHXYF-related and CD-related disease targets and they were found to be enriched in oxidative stress-related pathways and the PI3K/AKT signaling pathway. Molecular docking was then used to predict how the bioactive compounds would bind to the hub targets. It was found that quercetin could be the core bioactive compound and had good binding affinity to the top 5 hub targets. Finally, animal experiments were performed to further validate the findings, and the results revealed that QHXYF or quercetin inhibited 2,4,6-trinitrobenzenesulfonic acid-induced inflammation and oxidative stress processes by inhibiting the PI3K/AKT pathway, thereby improving CD symptoms. These findings suggest that QHXYF and quercetin may be potential novel treatments for CD.

Ion homeostasis, which is regulated by ion channels, is crucial for intracellular signaling. These channels are involved in diverse signaling pathways, including cell proliferation, migration, and intracellular calcium dynamics. Consequently, ion channel dysfunction can lead to various diseases. In addition, these channels are present in the plasma membrane and intracellular organelles. However, our understanding of the function of intracellular organellar ion channels is limited. Recent advancements in electrophysiological techniques have enabled us to record ion channels within intracellular organelles and thus learn more about their functions. Autophagy is a vital process of intracellular protein degradation that facilitates the breakdown of aged, unnecessary, and harmful proteins into their amino acid residues. Lysosomes, which were previously considered protein-degrading garbage boxes, are now recognized as crucial intracellular sensors that play significant roles in normal signaling and disease pathogenesis. Lysosomes participate in various processes, including digestion, recycling, exocytosis, calcium signaling, nutrient sensing, and wound repair, highlighting the importance of ion channels in these signaling pathways. This review focuses on different lysosomal ion channels, including those associated with diseases, and provides insights into their cellular functions. By summarizing the existing knowledge and literature, this review emphasizes the need for further research in this field. Ultimately, this study aims to provide novel perspectives on the regulation of lysosomal ion channels and the significance of ion-associated signaling in intracellular functions to develop innovative therapeutic targets for rare and lysosomal storage diseases.

Non-alcoholic fatty liver disease (NAFLD) is a complex disorder characterized by the accumulation of fat in the liver in the absence of excessive alcohol consumption. It is one of the most common liver diseases worldwide, affecting approximately 25% of the global population. It is closely associated with obesity, type 2 diabetes, and metabolic syndrome. Moreover, NAFLD can progress to non-alcoholic steatohepatitis, which can cause liver cirrhosis, liver failure, and hepatocellular carcinoma. Currently, there are no approved drugs for the treatment of NAFLD. Therefore, the development of effective drugs is essential for NAFLD treatment. In this article, we discuss the experimental models and novel therapeutic targets for NAFLD. Additionally, we propose new strategies for the development of drugs for NAFLD.

Numerous studies have revealed the importance of tumor-derived exosomes in rectal cancer (RC). This study aims to explore the influence of tumor-derived exosomal integrin beta-1 (ITGB1) on lung fibroblasts in RC along with underlying mechanisms. Exosome morphology was observed using a transmission electron microscope. Protein levels of CD63, CD9, ITGB1, p-p65 and p65 were detected using Western blot. To determine ITGB1's mRNA expression, quantitative real-time polymerase chain reaction was used. Moreover, levels of interleukin (IL)-8, IL-1β, and IL-6 in cell culture supernatant were measured via commercial ELISA kits. ITGB1 expression was increased in exosomes from RC cells. The ratio of p-p65/p65 as well as levels of interleukins in lung fibroblasts was raised by exosomes derived from RC cells, while was reduced after down-regulation of exosomal ITGB1. The increased ratio of p-p65/p65 as well as levels of pro-inflammatory cytokines caused by exosomes from RC cells was reversed by the addition of nuclear factor kappa B (NF-κB) inhibitor. We concluded that the knockdown of RC cells-derived exosomal ITGB1 repressed activation of lung fibroblasts and the NF-κB pathway in vitro.

This study aimed to assess the effects of exogenous hydrogen sulfide (H₂S) on abdominal aorta coarctation (AAC) induced myocardial fibrosis (MF) and autophagy in rats. Forty-four Sprague-Dawley rats were randomly divided into control group, AAC group, AAC + H₂S group, and H₂S control group. After a model of rats with AAC was built surgically, AAC + H₂S group and H₂S group were injected intraperitoneally with H₂S (100 μmol/kg) daily. The rats in the control group and the AAC group were injected with the same amount of PBS. We observed that H₂S can improve left ventricular function and the deposition of myocardial collagen fibers, inhibit pyroptosis, down-regulate the expression of P-eif2α in myocardial tissue, and inhibit cell autophagy by activating the phosphatidylinositol 3-kinase (PI3K)/AKT1 signaling pathway (p < 0.05). In addition, angiotensin II (1 μM) H9c2 cardiomyocytes were injured in vitro experiments, and it was also observed that pyroptosis was inhibited after H₂S (400 μmol/kg) intervention, the expression of P-eif2α in cardiomyocytes was significantly down-regulated, and the PI3K/AKT1 signaling pathway was activated at the same time. Therefore, increasing the expression of P-eif2α reverses the activation of the PI3K/AKT1 signaling pathway by H₂S. In conclusion, these findings suggest that exogenous H₂S can ameliorate MF in rats with AAC by inhibiting pyroptosis, and the mechanism may be associated with inhibiting the phosphorylation of eif2α and activating the PI3K/AKT1 signaling pathway to inhibit excessive cell autophagy.

The regeneration of myocardium following acute circulatory events remains a challenge, despite numerous efforts. Mesenchymal stem cells (MSCs) present a promising cell therapy option, but their differentiation into cardiomyocytes is a time-consuming process. Although it has been demonstrated that PSME4 degrades acetyl-YAP1, the role of PSME4 in the cardiac commitment of MSCs has not been fully elucidated. Here we reported the novel role of PSME4 in MSCs cardiac commitment. It was found that overnight treatment with apicidin in primary-cultured mouse MSCs led to rapid cardiac commitment, while MSCs from PSME4 knock-out mice did not undergo this process. Cardiac commitment was also observed using lentivirus-mediated PSME4 knockdown in immortalized human MSCs. Immunofluorescence and Western blot experiments revealed that YAP1 persisted in the nucleus of PSME4 knockdown cells even after apicidin treatment. To investigate the importance of YAP1 removal, MSCs were treated with shYAP1 and apicidin simultaneously. This combined treatment resulted in rapid YAP1 elimination and accelerated cardiac commitment. However, overexpression of acetylation-resistant YAP1 in apicidin-treated MSCs impeded cardiac commitment. In addition to apicidin, the universal effect of histone deacetylase (HDAC) inhibition on cardiac commitment was confirmed using tubastatin A and HDAC6 siRNA. Collectively, this study demonstrates that PSME4 is crucial for promoting the cardiac commitment of MSCs. HDAC inhibition acetylates YAP1 and facilitates its translocation to the nucleus, where it is removed by PSME4, promoting cardiac commitment. The failure of YAP1 to translocate or be eliminated from the nucleus results in the MSCs' inability to undergo cardiac commitment.

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor with high fatality. It has yet to be reported whether circ-SNX27 can affect the progression of HCC. This study attempted to analyze circ-SNX27's precise role and underlying mechanisms in HCC. HCC cell lines and tumor specimens from HCC patients were analyzed using quantitative real-time PCR and Western blotting to quantify the expressions of circ-SNX27, miR-375, and ribophorin I (RPN1). Cell invasion and cell counting kit 8 experiments were conducted for the evaluation of HCC cell invasion and proliferation. Caspase-3 Activity Assay Kit was utilized to gauge the caspase-3 activity. Luciferase reporter and RNA immunoprecipitation assays were executed to ascertain the relationships among miR-375, circ-SNX27, and RPN1. To determine how circ-SNX27 knockdown affects the growth of HCC xenografts in vivo, tumor-bearing mouse models were constructed. Elevated expressions of circ-SNX27 and RPN1 as well as a reduced miR-375 expression were observed among HCC cells and HCC patient tumor specimens. Knocking-down circ-SNX27 in HCC cells abated their proliferative and invasive abilities but raised their caspase-3 activity. Moreover, the poor levels of circ-SNX27 inhibited HCC tumor growth among the mice. Circ-SNX27 enhanced RPN1 by competitively binding with miR-375. Silencing miR-375 in HCC cells promoted their malignant phenotypes. Nonetheless, the promotive effect of miR-375 silencing was reversible via the knockdown of circ-SNX27 or RPN1. This research demonstrated that circ-SNX27 accelerated the progression of HCC by modulating the miR-375/RPN1 axis. This is indicative of circ-SNX27's potential as a target for the treatment of HCC.

Voltage-dependent K⁺ (Kv) channels are widely expressed on vascular smooth muscle cells and regulate vascular tone. Here, we explored the inhibitory effect of encainide, a class Ic anti-arrhythmic agent, on Kv channels of vascular smooth muscle from rabbit coronary arteries. Encainide inhibited Kv channels in a concentration-dependent manner with an IC₅₀ value of 8.91 ± 1.75 μM and Hill coefficient of 0.72 ± 0.06. The application of encainide shifted the activation curve toward a more positive potential without modifying the inactivation curve, suggesting that encainide inhibited Kv channels by altering the gating property of channel activation. The inhibition by encainide was not significantly affected by train pulses (1 and 2 Hz), indicating that the inhibition is not use (state)-dependent. The inhibitory effect of encainide was reduced by pretreatment with the Kv1.5 subtype inhibitor. However, pretreatment with the Kv2.1 subtype inhibitor did not alter the inhibitory effects of encainide on Kv currents. Based on these results, encainide inhibits vascular Kv channels in a concentration-dependent and use (state)-independent manner by altering the voltage sensor of the channels. Furthermore, Kv1.5 is the main Kv subtype involved in the effect of encainide.