Aberrant splicing of CaV1.2 calcium channel induced by decreased Rbfox1 enhances arterial constriction during diabetic hyperglycemia.

Diabetic hyperglycemia induces dysfunctions of arterial smooth muscle, leading to diabetic vascular complications. The CaV1.2 calcium channel is one primary pathway for Ca2+ influx, which initiates vasoconstriction. However, the long-term regulation mechanism(s) for vascular CaV1.2 functions under hyperglycemic condition remains unknown. Here, Sprague-Dawley rats fed with high-fat diet in combination with low dose streptozotocin and Goto-Kakizaki (GK) rats were used as diabetic models. Isolated mesenteric arteries (MAs) and vascular smooth muscle cells (VSMCs) from rat models were used to assess K+-induced arterial constriction and CaV1.2 channel functions using vascular myograph and whole-cell patch clamp, respectively. K+-induced vasoconstriction is persistently enhanced in the MAs from diabetic rats, and CaV1.2 alternative spliced exon 9* is increased, while exon 33 is decreased in rat diabetic arteries. Furthermore, CaV1.2 channels exhibit hyperpolarized current-voltage and activation curve in VSMCs from diabetic rats, which facilitates the channel function. Unexpectedly, the application of glycated serum (GS), mimicking advanced glycation end-products (AGEs), but not glucose, downregulates the expression of the splicing factor Rbfox1 in VSMCs. Moreover, GS application or Rbfox1 knockdown dynamically regulates alternative exons 9* and 33, leading to facilitated functions of CaV1.2 channels in VSMCs and MAs. Notably, GS increases K+-induced intracellular calcium concentration of VSMCs and the vasoconstriction of MAs. These results reveal that AGEs, not glucose, long-termly regulates CaV1.2 alternative splicing events by decreasing Rbfox1 expression, thereby enhancing channel functions and increasing vasoconstriction under diabetic hyperglycemia. This study identifies the specific molecular mechanism for enhanced vasoconstriction under hyperglycemia, providing a potential target for managing diabetic vascular complications.

Association of glucose-lowering drug target and risk of gastrointestinal cancer: a mendelian randomization study.

BACKGROUND & AIMS: Glucose-lowering drug is associated with various cancers, but the causality with gastrointestinal cancer risk is rarely reported. We aimed to explore the causality between them in this Mendelian randomization (MR) study. METHODS: Two-sample MR, summary-data-based (SMR), mediation MR, and colocalization analyses was employed. Ten glucose-lowering drug targets (PPARG, DPP4, GLP1R, INSR, SLC5A2, ABCC8, KCNJ11, ETFDH, GPD2, PRKAB1) and seven types of gastrointestinal cancer (anal carcinoma, cardia cancer, gastric cancer, hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), pancreatic cancer, rectum cancer) were included. Patients with gastrointestinal cancers from six different large GWAS databases, including the UK Biobank and Finnish cohorts were incorporated, for discovery and external validation. Meta-analysis was employed to integrate the results from both discovery and validation cohorts, thereby ensuring the reliability of findings. RESULTS: ABCC8/KCNJ11 were associated with pancreatic cancer risk in both two-sample MR (odds ratio (OR): 15.058, per standard deviation unit (SD) change of glucose-lowering durg target perturbation equivalent to 1 SD unit of HbA1c lowering; 95% confidence interval (95% CI): 3.824-59.295; P-value = 0.0001) and SMR (OR: 1.142; 95% CI: 1.013-1.287; P-value = 0.030) analyses. The mediation effect of body mass index (OR: 0.938; 95% CI: 0.884-0.995; proportion of mediation effect: 3.001%; P-value = 0.033) on ABCC8/KCNJ11 and pancreatic cancer was uncovered. Strong connections of DPP4 with anal carcinoma (OR: 0.123; 95% CI: 0.020-0.745; P-value = 0.023) and ICC (OR: 7.733; 95% CI: 1.743-34.310; P-value = 0.007) were detected. PPARG was associated with anal carcinoma (OR: 12.909; 95% CI: 3.217-51.795; P-value = 0.0003), HCC (OR: 36.507; 95% CI: 8.929-149.259; P-value < 0.0001), and pancreatic cancer (OR: 0.110; 95% CI: 0.071-0.172; P-value < 0.0001). SLC5A2 was connected with pancreatic cancer (OR: 8.096; 95% CI: 3.476-18.857; P-value < 0.0001). Weak evidence indicated the connections of GLP1R, GPD2, and PRKAB1 with anal carcinoma, cardia cancer, ICC, and rectum cancer. In addition, the corresponding results were consistently validated in both the validation cohorts and the integrated outcomes. CONCLUSIONS: Some glucose-lowering drugs were associated with gastrointestinal cancer risk, which might provide new ideas for gastrointestinal cancer treatment.

Association between gut microbiota and gastrointestinal cancer: a two-sample bi-directional Mendelian randomization study.

Background: The gut microbiome is closely related to gastrointestinal (GI) cancer, but the causality of gut microbiome with GI cancer has yet to be fully established. We conducted this two-sample Mendelian randomization (MR) study to reveal the potential causal effect of gut microbiota on GI cancer. Materials and methods: Summary-level genetic data of gut microbiome were derived from the MiBioGen consortium and the Dutch Microbiome Project. Summary statistics of six GI cancers were drawn from United Kingdom Biobank. Inverse-variance-weighted (IVW), MR-robust adjusted profile score (MR-RAPS), and weighted-median (WM) methods were used to evaluate the potential causal link between gut microbiota and GI cancer. In addition, we performed sensitivity analyses and reverse MR analyses. Results: We identified potential causal associations between 21 bacterial taxa and GI cancers (values of p < 0.05 in all three MR methods). Among them, phylum Verrucomicrobia (OR: 0.17, 95% CI: 0.05-0.59, p = 0.005) retained a strong negative association with intrahepatic cholangiocarcinoma after the Bonferroni correction, whereas order Bacillales (OR: 1.67, 95% CI: 1.23-2.26, p = 0.001) retained a strong positive association with pancreatic cancer. Reverse MR analyses indicated that GI cancer was associated with 17 microbial taxa in all three MR methods, among them, a strong inverse association between colorectal cancer and family Clostridiaceae1 (OR: 0.91, 95% CI: 0.86-0.96, p = 0.001) was identified by Bonferroni correction. Conclusion: Our study implicates the potential causal effects of specific microbial taxa on GI cancer, potentially providing new insights into the prevention and treatment of GI cancer through specific gut bacteria.

Association Between Autoimmune Diseases and Sarcopenia: A Two-Sample Mendelian Randomization Study.

Purpose: Observational studies have reported that autoimmune diseases are closely related to sarcopenia, but the causalities of autoimmune diseases with sarcopenia have not been established. We conducted this Mendelian randomization (MR) study to reveal the causal associations of overall autoimmune disease and five common autoimmune diseases with sarcopenia-related traits. Methods: The publicly available summary-level data of autoimmune diseases and three sarcopenia-related traits were used for analysis. The causal effects of autoimmune diseases on sarcopenia-related traits were first identified in discovery samples using the inverse-variance-weighted method as the primary method, and the robustness of results was examined by additional sensitivity analyses. Replication MR analyses were then conducted using replication samples of five autoimmune diseases. Finally, the possibility of reverse causation was assessed by reverse MR analyses. Results: In both the discovery and replication samples, we identified potential causal effects of rheumatoid arthritis (RA) on appendicular lean mass (ALM) and low grip strength (OR = 0.979, 95% CI: 0.964-0.995 for ALM; OR = 1.042, 95% CI: 1.013-1.072 for low grip strength), but not on walking pace. We also found that inflammatory bowel disease (IBD) and type 1 diabetes (T1D) were only causally negatively associated with ALM in the discovery stage (OR = 0.986, 95% CI: 0.974-0.999 for IBD; OR = 0.987, 95% CI: 0.975-0.999 for T1D), whereas systemic lupus erythematosus, multiple sclerosis, and overall autoimmune disease were not associated with any of the three sarcopenia-related traits. Additionally, reverse MR analysis only found an association between walking pace and overall autoimmune disease, but this association did not remain in the weighted-median method. Conclusion: This study demonstrates that RA is causally associated with low grip strength and reduced ALM, and that IBD and T1D may be causally negatively related to ALM.

Dysregulated Rbfox2 produces aberrant splicing of CaV1.2 calcium channel in diabetes-induced cardiac hypertrophy.

BACKGROUND: L-type Ca2+ channel CaV1.2 is essential for cardiomyocyte excitation, contraction and gene transcription in the heart, and abnormal functions of cardiac CaV1.2 channels are presented in diabetic cardiomyopathy. However, the underlying mechanisms are largely unclear. The functions of CaV1.2 channels are subtly modulated by splicing factor-mediated alternative splicing (AS), but whether and how CaV1.2 channels are alternatively spliced in diabetic heart remains unknown. METHODS: Diabetic rat models were established by using high-fat diet in combination with low dose streptozotocin. Cardiac function and morphology were assessed by echocardiography and HE staining, respectively. Isolated neonatal rat ventricular myocytes (NRVMs) were used as a cell-based model. Cardiac CaV1.2 channel functions were measured by whole-cell patch clamp, and intracellular Ca2+ concentration was monitored by using Fluo-4 AM. RESULTS: We find that diabetic rats develop diastolic dysfunction and cardiac hypertrophy accompanied by an increased CaV1.2 channel with alternative exon 9* (CaV1.2E9*), but unchanged that with alternative exon 8/8a or exon 33. The splicing factor Rbfox2 expression is also increased in diabetic heart, presumably because of dominate-negative (DN) isoform. Unexpectedly, high glucose cannot induce the aberrant expressions of CaV1.2 exon 9* and Rbfox2. But glycated serum (GS), the mimic of advanced glycation end-products (AGEs), upregulates CaV1.2E9* channels proportion and downregulates Rbfox2 expression in NRVMs. By whole-cell patch clamp, we find GS application hyperpolarizes the current-voltage curve and window currents of cardiac CaV1.2 channels. Moreover, GS treatment raises K+-triggered intracellular Ca2+ concentration ([Ca2+]i), enlarges cell surface area of NRVMs and induces hypertrophic genes transcription. Consistently, siRNA-mediated knockdown of Rbfox2 in NRVMs upregulates CaV1.2E9* channel, shifts CaV1.2 window currents to hyperpolarization, increases [Ca2+]i and induces cardiomyocyte hypertrophy. CONCLUSIONS: AGEs, not glucose, dysregulates Rbfox2 which thereby increases CaV1.2E9* channels and hyperpolarizes channel window currents. These make the channels open at greater negative potentials and lead to increased [Ca2+]i in cardiomyocytes, and finally induce cardiomyocyte hypertrophy in diabetes. Our work elucidates the underlying mechanisms for CaV1.2 channel regulation in diabetic heart, and targeting Rbfox2 to reset the aberrantly spliced CaV1.2 channel might be a promising therapeutic approach in diabetes-induced cardiac hypertrophy.

Serum lactate and the mortality of critically ill patients in the emergency department: A retrospective study.

Serum lactate levels have been widely studied as a prognostic marker in critically ill patients, particularly those in the intensive care unit. However, it remains unknown whether the serum lactate levels affect the mortality rate of critically ill patients admitted to hospital. To investigate this hypothesis, the vital signs and blood gas analysis data of 1,393 critically ill patients who visited the Emergency Department of Affiliated Kunshan Hospital of Jiangsu University (Kunshan, China) between January and December 2021 were collected. Patients were divided into two groups, 30-day survival group and a 30-day death group, and logistic regression analysis was used to investigate the association between vital signs, laboratory results and mortality rates of critically ill patients. A total of 1,393 critically ill patients was enrolled in the present study, with a male-to-female ratio of 1.17:1.00, a mean age of 67.72±19.29 years and a mortality rate of 11.6%. The multivariate logistic regression analysis revealed that increased serum lactate levels were an independent risk factor for mortality rate of critically ill patients [Odds ratio (OR)=1.50, 95% confidence interval (95% CI): 1.40-1.62]. The critical cut-off value for the serum lactate levels was identified as 2.35 mmol/l. In addition, OR values of age, heart rate, systolic blood pressure, transcutaneous oxygen saturation (SpO2) and hemoglobin were 1.02, 1.01, 0.99, 0.96 and 0.99, respectively (95% CI: 1.01-1.04, 1.00-1.02, 0.98-0.99, 0.94-0.98 and 0.98-1.00, respectively). The logistic regression model was found to be of value in terms of identifying the mortality rate of patients and the area under the receiver operating characteristic curve was 0.894 (95% CI: 0.863-0.925; P<0.001). In conclusion, the present study showed that high serum lactate levels in critically ill patients upon admission to hospital are associated with higher 30-day mortality rate.

Whole-exome sequencing and electrophysiological study reveal a novel loss-of-function mutation of KCNA10 in epinephrine provoked long QT syndrome with familial history of sudden cardiac death.

Congenital long QT syndrome (LQTS) is one type of inherited fatal cardiac arrhythmia that may lead to sudden cardiac death (SCD). Mutations in more than 16 genes have been reported to be associated with LQTS, whereas the genetic causes of about 20% of cases remain unknown. In the present study, we investigated a four-generation pedigree with familial history of syncope and SCD. The proband was a 33-year-old young woman who experienced 3 episodes of syncope when walking at night. The electrocardiogram revealed a markedly epinephrine-provoked prolonged QT interval (QT = 468 ms, QTc = 651 ms) but no obvious arrhythmia in the resting state. Three family members have died of suspected SCD. Whole-exome sequencing and bioinformatic analysis based on pedigree revealed that a novel missense mutation KCNA10 (c.1397G＞A/Arg466Gln) was the potential genetic lesion. Sanger sequencing was performed to confirm the whole-exome sequencing results. This mutation resulted in the KV1.8 channel amino acid residue 466 changing from arginine to glutamine, and the electrophysiological experiments verified it as a loss-of-function mutation of KV1.8, which reduced the K+ currents of KV1.8 and might result in the prolonged QT interval. These findings suggested that KCNA10 (c.1397G＞A) mutation was possibly pathogenic in this enrolled LQTS family, and may provide a new potential genetic target for diagnosis and counseling of stress-related LQTS families as well as the postmortem diagnosis of SCD.

Fibrillin-1 mutation contributes to Marfan syndrome by inhibiting Cav1.2-mediated cell proliferation in vascular smooth muscle cells.

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by mutation in fibrillin-1 (FBN1). However, the molecular mechanism underlying MFS remains poorly understood. The study aimed to explore how the L-type calcium channel (CaV1.2) modulates disease progression of MFS and to identify a potential effective target for attenuating MFS. KEGG enrichment analysis showed that the calcium signaling pathway gene set was significantly enriched. We demonstrated that FBN1 deficiency exhibited inhibition on both the expression of Cav1.2 and proliferation of vascular smooth muscle cells (VSMCs). Then, we examined whether FBN1 mediates Cav1.2 via regulating TGF-ß1. Higher levels of TGF-ß1 were observed in the serum and aortic tissues from patients with MFS. TGF-ß1 modulated Cav1.2 expression in a concentration-dependent manner. We evaluated the role of Cav1.2 in MFS by small interfering RNA and Cav1.2 agonist Bay K8644. The effect of Cav1.2 on cell proliferation was dependent on c-Fos activity. These results demonstrated FBN1 deficiency decreased the expression levels of Cav1.2 via regulation of TGF-ß1, and downregulation of Cav1.2 inhibited cell proliferation of human aortic smooth muscle cells (HASMCs) in MFS patients. These findings suggest that Cav1.2 may be an appealing therapeutic target for MFS.

Machine Learning to Predict the Response to Lenvatinib Combined with Transarterial Chemoembolization for Unresectable Hepatocellular Carcinoma.

BACKGROUND: Lenvatinib and transarterial chemoembolization (TACE) are first-line treatments for unresectable hepatocellular carcinoma (HCC), but the objective response rate (ORR) is not satisfactory. We aimed to predict the response to lenvatinib combined with TACE before treatment for unresectable HCC using machine learning (ML) algorithms based on clinical data. METHODS: Patients with unresectable HCC receiving the combination therapy of lenvatinib combined with TACE from two medical centers were retrospectively collected from January 2020 to December 2021. The response to the combination therapy was evaluated over the following 4-12 weeks. Five types of ML algorithms were applied to develop the predictive models, including classification and regression tree (CART), adaptive boosting (AdaBoost), extreme gradient boosting (XGBoost), random forest (RF), and support vector machine (SVM). The performance of the models was assessed by the receiver operating characteristic (ROC) curve and area under the receiver operating characteristic curve (AUC). The Shapley Additive exPlanation (SHAP) method was applied to explain the model. RESULTS: A total of 125 unresectable HCC patients were included in the analysis after the inclusion and exclusion criteria, among which 42 (33.6%) patients showed progression disease (PD), 49 (39.2%) showed stable disease (SD), and 34 (27.2%) achieved partial response (PR). The nonresponse group (PD + SD) included 91 patients, while the response group (PR) included 34 patients. The top 40 most important features from all 64 clinical features were selected using the recursive feature elimination (RFE) algorithm to develop the predictive models. The predictive power was satisfactory, with AUCs of 0.74 to 0.91. The SVM model and RF model showed the highest accuracy (86.5%), and the RF model showed the largest AUC (0.91, 95% confidence interval (CI): 0.61-0.95). The SHAP summary plot and decision plot illustrated the impact of the top 40 features on the efficacy of the combination therapy, and the SHAP force plot successfully predicted the efficacy at the individualized level. CONCLUSIONS: A new predictive model based on clinical data was developed using ML algorithms, which showed favorable performance in predicting the response to lenvatinib combined with TACE for unresectable HCC. Combining ML with SHAP could provide an explicit explanation of the efficacy prediction.

Association of gut microbiome and primary liver cancer: A two-sample Mendelian randomization and case-control study.

BACKGROUND AND AIMS: Observational epidemiology studies suggested a relationship between the gut microbiome and primary liver cancer. However, the causal relationship remains unclear because of confounding factors and reverse causality. We aimed to explore the causal role of the gut microbiome in the development of primary liver cancer, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). METHODS: Mendelian randomization (MR) study was conducted using summary statistics from genome-wide association studies (GWAS) of the gut microbiome and liver cancer, and sequencing data from a case-control study validated the findings. A 5-cohort GWAS study in Germany (N = 8956) served as exposure, whilst the UK biobank GWAS study (N = 456 348) served as an outcome. The case-control study was conducted at the First Affiliated Hospital of Wenzhou Medical University from December 2018 to October 2020 and included 184 HCC patients, 63 ICC patients and 40 healthy controls. RESULTS: A total of 57 features were available for MR analysis, and protective causal associations were identified for Family_Ruminococcaceae (OR = 0.46 [95% CI, 0.26-0.82]; p = .009) and Genus_Porphyromonadaceae (OR = 0.59 [95% CI, 0.42-0.83]; p = .003) with HCC, and for Family_Porphyromonadaceae (OR = 0.36 [95% CI, 0.14-0.94]; p = .036) and Genus_Bacteroidetes (OR = 0.55 [95% CI, 0.34-0.90]; p = .017) with ICC respectively. The case-control study results showed that the healthy controls had a higher relative abundance of Family_Ruminococcaceae (p = .00033), Family_Porphyromonadaceae (p = .0055) and Genus_Bacteroidetes (p = .021) than the liver cancer patients. CONCLUSIONS: This study demonstrates that Ruminococcaceae, Porphyromonadaceae and Bacteroidetes are related to a reduced risk of liver cancer (HCC or ICC), suggesting potential significance for the prevention and control of liver cancer.

Formononetin: A Pathway to Protect Neurons.

Formononetin (FMN) is a phytoestrogen member of the flavonoid family, which has the pharmacological effects of antioxidative, antihypertensive, antitumor, and anti-infective. FMN demonstrates potential in the prevention and treatment of diseases, specifically neurological diseases, such as traumatic brain injury (TBI), spinal cord injury (SCI), ischemic stroke, cerebral ischemia-reperfusion, Alzheimer's disease, and nerve tumor. Herein, a literature search is conducted to provide information on the signaling pathways of neuroprotection of formononetin based on the neuroprotective study. The significant neuroprotective function of FMN makes it a novel candidate for the development of drugs targeting the central nervous system.

Association between dried fruit intake and pan-cancers incidence risk: A two-sample Mendelian randomization study.

Background: Observational studies have revealed that dried fruit intake may be associated with cancer incidence; however, confounding factors make the results prone to be disturbed. Therefore, we conducted a two-sample Mendelian randomization (MR) study to explore the causal relationship between dried fruit intake and 11 site-specific cancers. Materials and methods: Forty-three single nucleoside polymers (SNPs) with robust genome-wide association study (GWAS) evidence, strongly correlated with dried fruit intake, were used as instrumental variables (IVs) in this study. The summary-level genetic datasets of site-specific cancers were obtained from the Oncoarray oral cavity and oropharyngeal cancer consortium, International Lung Cancer Consortium, Breast Cancer Association Consortium (BCAC), Ovarian Cancer Association Consortium, PanScan1, and GWAS of other scholars. We analyzed the causality between dried fruit intake and 11 site-specific cancers using the inverse-variance-weighted (IVW) and weighted median (WM) methods. For the results of the MR analysis, Cochran's Q test was used to check for heterogeneity, and multiplicative random effects were used to evaluate the heterogeneity further. Gene pleiotropy was tested using MR-Egger regression and MR-PRESSO methods. In addition, the main results of this study were validated by using the summary statistical data from the FinnGen and UK Biobank databases, and adjusted body mass index (BMI), years of education, fresh fruit intake, and vitamin C using multivariable MR analysis to ensure the stability of the research results. Results: The evidence from IVW analyses showed that each increase of dried fruit intake by one standard deviation was statistically significantly associated with 82.68% decrease of oral cavity/pharyngeal cancer incidence risk (P = 0.0131), 67.01% decrease of lung cancer incidence risk (P = 0.0011), 77% decrease of squamous cell lung cancer incidence risk (P = 0.0026), 53.07% decrease of breast cancer incidence risk (P = 4.62 × 10-5), 39.72% decrease of ovarian cancer incidence risk (P = 0.0183), 97.26% decrease of pancreatic cancer incidence risk (P = 0.0280), 0.53% decrease of cervical cancer incidence risk (P = 0.0482); however, there was no significant effect on lung adenocarcinoma (P = 0.4343), endometrial cancer (P = 0.8742), thyroid cancer (P = 0.6352), prostate cancer (P = 0.5354), bladder cancer (P = 0.8996), and brain cancer (P = 0.8164). In the validation part of the study results, the causal relationship between dried fruit intake and lung cancer (P = 0.0043), squamous cell lung cancer (P = 0.0136), and breast cancer (P = 0.0192) was determined. After adjusting for the potential impact of confounders, the causal relationship between dried fruit intake and lung cancer (P = 0.0034), squamous cell lung cancer (P = 0.046), and breast cancer (P = 0.0001) remained. The sensitivity analysis showed that our results were stable and reliable. Conclusion: The intake of dried fruits may have a protective effect against some site-specific cancers. Therefore, health education and a reasonable adjustment of dietary proportions may help in the primary prevention of cancer.

Norepinephrine acting on adventitial fibroblasts stimulates vascular smooth muscle cell proliferation via promoting small extracellular vesicle release.

Excessive sympathetic activity and norepinephrine (NE) release play crucial roles in the pathogeneses of hypertension. Sympathetic fibers innervate adventitia rather than media of arteries. However, the roles of NE in adventitial fibroblasts (AFs) are unknown. This study investigated the roles of NE in regulating AFs-derived extracellular vesicles (EVs) release and vascular smooth muscle cells (VSMCs) proliferation in hypertension. Methods: AFs and VSMCs were prepared from aorta of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). AFs were treated with NE (10 µM) for 24 h (every 6 h, 4 times), and cultured in exosomes-depleted medium for 48 h. EVs were isolated from AFs medium with ultracentrifugation for identification and transfer to VSMCs. Results: NE promoted AFs phenotypic transformation and proliferation, which were prevented by α-receptor antagonist phentolamine rather than ß-receptor antagonist propranolol. NE-treated AFs conditioned medium stimulated VSMCs proliferation, which was inhibited by either exosome inhibitor GW4869 or phentolamine. NE increased small EVs number, diameter and angiotensin converting enzyme (ACE) contents. The NE-induced EVs release was abolished by GW4869. The EVs from NE-treated AFs stimulated VSMCs proliferation, which was prevented by angiotensin II type 1 receptor antagonist losartan. The EVs from the ACE knockdown-treated AFs showed lower ACE contents, and lost their roles in stimulating VSMCs proliferation. Conclusion: NE promotes AFs-derived small EVs release and ACE transfer, and then causes VSMCs proliferation in hypertension. Intervention of AFs-derived EVs release may be potential therapeutics for excessive sympathetic activation-related vascular remodeling in hypertension.

International student perceptions of online medical education during the COVID-19 epidemic.

This study aimed to investigate how international students enrolled on medical and surgical bachelor's degree programs (MBBS) in China perceived online medical education course, compared to native Chinese students during the Covid-19 pandemic. The perceptions of 38 MBBS and 31 Chinese sophomores were surveyed using the Chaoxing platform. The international student group's mean satisfaction with online teaching was 2.737 on a 5-point scale, much lower than the Chinese students' mean score of 4.355 (p < 0.05). Similarly, the international students expressed less satisfaction than the Chinese learners with other aspects of the course, including the teacher's level, at 3.964 ± 0.818 versus 4.445 ± 0.548 (p < 0.05); curriculum organization, at 3.651 ± 0.848 versus 4.333 ± 0.568 (p < 0.05); and self-learning level, at 3.634 ± 0.996 versus 3.686 ± 0.949 (p > 0.05), respectively. There were also noteworthy differences between the progress made by the international students in Chinese language learning, which was positively correlated with satisfaction with teaching on the online medical education (p < 0.05). The results suggest that, while online teaching was a necessary response to the Covid-19 pandemic, satisfaction with this mode of education is lower among international students than their Chinese counterparts.

Diminished Rbfox1 increases vascular constriction by dynamically regulating alternative splicing of CaV1.2 calcium channel in hypertension.

Calcium influx from depolarized CaV1.2 calcium channels triggers the contraction of vascular smooth muscle cells (VSMCs), which is important for maintaining vascular myogenic tone and blood pressure. The function of CaV1.2 channel can be subtly modulated by alternative splicing (AS), and its aberrant splicing involves in the pathogenesis of multiple cardiovascular diseases. The RNA-binding protein Rbfox1 is reported to regulate the AS events of CaV1.2 channel in the neuronal development, but its potential roles in vascular CaV1.2 channels and vasoconstriction remain undefined. Here, we detect Rbfox1 is expressed in rat vascular smooth muscles. Moreover, the protein level of Rbfox1 is dramatically decreased in the hypertensive small arteries from spontaneously hypertensive rats in comparison with normotensive ones from Wistar-Kyoto rats. In VSMCs, Rbfox1 could dynamically regulate the AS of CaV1.2 exons 9* and 33. By whole-cell patch clamp, we identify knockdown of Rbfox1 induces the hyperpolarization of CaV1.2 current-voltage relationship curve in VSMCs. Furthermore, siRNA-mediated knockdown of Rbfox1 increases the K+-induced constriction of rat mesenteric arteries. In summary, our results indicate Rbfox1 modulates vascular constriction by dynamically regulating CaV1.2 alternative exons 9* and 33. Therefore, our work elucidates the underlying mechanisms for CaV1.2 channels regulation and provides a potential therapeutic target for hypertension.

RND3 attenuates oxidative stress and vascular remodeling in spontaneously hypertensive rat via inhibiting ROCK1 signaling.

Superoxide and vascular smooth muscle cells (VSMCs) migration and proliferation play crucial roles in the vascular remodeling. Vascular remodeling contributes to the development and complications of hypertension. Rho family GTPase 3 (RND3 or RhoE), an atypical small Rho-GTPase, is known to be involved in cancer development and metastasis. However, the roles of RND3 in superoxide production and cardiovascular remodeling are unknown. Here, we uncovered the critical roles of RND3 in attenuating superoxide production, VSMCs migration and proliferation, and vascular remodeling in hypertension and its underline mechanisms. VSMCs were isolated and prepared from thoracic aorta of Male Wistar-Kyoto rat (WKY) and spontaneously hypertensive rat (SHR). RND3 mRNA and protein expressions in arteries and VSMCs were down-regulated in SHR. RND3 overexpression in VSMCs reduced NAD(P)H oxidase (NOX) activity, NOX1 and NOX2 expressions, mitochondria superoxide generation, and H2O2 production in SHR. Moreover, the RND3 overexpression inhibited VSMCs migration and proliferation in SHR, which were similar to the effects of NOX1 inhibitor ML171 plus NOX2 inhibitor GSK2795039. Rho-associated kinase 1 (ROCK1) and RhoA expressions and myosin phosphatase targeting protein 1 (MYPT1) phosphorylation in VSMCs were increased in SHR, which were prevented by RND3 overexpression. ROCK1 overexpression promoted NOX1 and NOX2 expressions, superoxide and H2O2 production, VSMCs migration and proliferation in both WKY and SHR, which were attenuated by RND3 overexpression. Adenoviral-mediated RND3 overexpression in SHR attenuated hypertension, vascular remodeling and oxidative stress. These results indicate that RND3 attenuates VSMCs migration and proliferation, hypertension and vascular remodeling in SHR via inhibiting ROCK1-NOX1/2 and mitochondria superoxide signaling.

Inhibition of miR-135a-5p attenuates vascular smooth muscle cell proliferation and vascular remodeling in hypertensive rats.

Proliferation of vascular smooth muscle cells (VSMCs) greatly contributes to vascular remodeling in hypertension. This study is to determine the roles and mechanisms of miR-135a-5p intervention in attenuating VSMC proliferation and vascular remodeling in spontaneously hypertensive rats (SHRs). MiR-135a-5p level was raised, while fibronectin type III domain-containing 5 (FNDC5) mRNA and protein expressions were reduced in VSMCs of SHRs compared with those of Wistar-Kyoto rats (WKYs). Enhanced VSMC proliferation in SHRs was inhibited by miR-135a-5p knockdown or miR-135a-5p inhibitor, but exacerbated by miR-135a-5p mimic. VSMCs of SHRs showed reduced myofilaments, increased or even damaged mitochondria, increased and dilated endoplasmic reticulum, which were attenuated by miR-135a-5p inhibitor. Dual-luciferase reporter assay shows that FNDC5 was a target gene of miR-135a-5p. Knockdown or inhibition of miR-135a-5p prevented the FNDC5 downregulation in VSMCs of SHRs, while miR-135a-5p mimic inhibited FNDC5 expressions in VSMCs of both WKYs and SHRs. FNDC5 knockdown had no significant effects on VSMC proliferation of WKYs, but aggravated VSMC proliferation of SHRs. Exogenous FNDC5 or FNDC5 overexpression attenuated VSMC proliferation of SHRs, and prevented miR-135a-5p mimic-induced enhancement of VSMC proliferation of SHR. MiR-135a-5p knockdown in SHRs attenuated hypertension, normalized FNDC5 expressions and inhibited vascular smooth muscle proliferation, and alleviated vascular remodeling. These results indicate that miR-135a-5p promotes while FNDC5 inhibits VSMC proliferation in SHRs. Silencing of miR-135a-5p attenuates VSMC proliferation and vascular remodeling in SHRs via disinhibition of FNDC5 transcription. Either inhibition of miR-135a-5p or upregulation of FNDC5 may be a therapeutically strategy in attenuating vascular remodeling and hypertension.

A novel mutation in KCNH2 yields loss-of-function of hERG potassium channel in long QT syndrome 2.

Mutations in hERG (human ether-à-go-go-related gene) potassium channel are closely associated with long QT syndromes. By direct Sanger sequencing, we identified a novel KCNH2 mutation W410R in the patient with long QT syndrome 2 (LQT2). However, the electrophysiological functions of this mutation remain unknown. In comparison to hERGWT channels, hERGW410R channels have markedly decreased total and surface expressions. W410R mutation dramatically reduces hERG channel currents (IKr) and shifts its steady-state activation curve to depolarization. Moreover, hERGW410R channels make dominant-negative effects on hERGWT channels. Significantly, we find hERG channel blocker E-4031 could partially rescue the function of hERGW410R channels by increasing the membrane expression. By using in silico model, we reveal that hERGW410R channels obviously elongate the repolarization of human ventricular myocyte action potentials. Collectively, W410R mutation decreases the currents of hERG channel, because of diminished membrane expression of mutant channels, that subsequently leads to elongated repolarization of cardiomyocyte, which might induce the pathogenesis of LQT2. Furthermore, E-4031 could partially rescue the decreased activity of hERGW410R channels. Thus, our work identifies a novel loss-of-function mutation in KCNH2 gene, which might provide a rational basis for the management of LQT2.

[A preliminary study on the construction of the triad medical experimental system].

The traditional medical experiment based on animal studies fails to reflect competency-oriented goal, and is not closely combined with clinical and scientific research, which does not meet the need for early clinical and scientific training. In order to cultivate the first-class medical talents, medical experimental teaching should conform to the trend of modern medical education, innovate teaching ideas and models, and update the hardware and software in time. Therefore, our teaching center adopts the triad medical experimental system which consists of "animal experiments, human functional experiments, and electronic standardized patient (ESP)-based virtual simulation experiments", and uses one system to integrate basic and clinical medicine, practice and virtual learning, teaching and scientific training. The system retains the core content of traditional animal experiments, and includes the most mature and widely used human physiological experiments to increase students' learning experience. With medical simulation experiment, it explains the specific physiological and pathophysiological processes of human body to improve students' cognitive and thinking ability. Here, we provide a systematic description on our triad medical experimental system, and discuss the experience to establish this novel system.