A specific inflammatory suppression fibroblast subpopulation characterized by MHCII expression in human dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is a significant cause of heart failure that requires heart transplantation. Fibroblasts play a central role in the fibro-inflammatory microenvironment of DCM. However, their cellular heterogeneity and interaction with immune cells have not been well identified. An integrative analysis was conducted on single-cell RNA sequencing (ScRNA-Seq) data from human left ventricle tissues, which comprised 4 hearts from healthy donors and 6 hearts with DCM. The specific antigen-presenting fibroblast (apFB) was explored as a subtype of fibroblasts characterized by expressing MHCII genes, the existence of which was confirmed by immunofluorescence staining of 3 cardiac tissues from DCM patients with severe heart failure. apFB highly expressed the genes that response to IFN-γ, and it also have a high activity of the JAK-STAT pathway and the transcription factor RFX5. In addition, the analysis of intercellular communication between apFBs and CD4+T cells revealed that the anti-inflammatory ligand-receptor pairs TGFB-TGFR, CLEC2B-KLRB1, and CD46-JAG1 were upregulated in DCM. The apFB signature exhibited a positive correlation with immunosuppression and demonstrated diagnostic and prognostic value when evaluated using a bulk RNA dataset comprising 166 donors and 166 DCM samples. In conclusion, the present study identified a novel subpopulation of fibroblasts that specifically expresses MHCII-encoding genes. This specific apFBs can suppress the inflammation occurring in DCM. Our findings further elucidate the composition of the fibro-inflammatory microenvironment in DCM, and provide a novel therapeutic target.

Hydrogen Sulfide Ameliorates Heart Aging by Downregulating Matrix Metalloproteinase-9.

PURPOSE: Aging contributes significantly to cardiovascular diseases and cardiac dysfunction, leading to the upregulation of matrix metalloproteinase-9 (MMP-9) in the heart and a significant decrease in hydrogen sulfide (H2S) content, coupled with impaired cardiac diastolic function. This study explores whether supplementing exogenous hydrogen sulfide during aging ameliorates the decline in H2S concentration in the heart, suppresses MMP-9 expression, and improves the age-associated impairment in cardiac morphology and function. METHODS: We collected plasma from healthy individuals of different ages to determine the relationship between aging and H2S and MMP-9 levels through Elisa detection and liquid chromatography-tandem mass spectrometry (LC/MC) detection of plasma H2S content. Three-month-old mice were selected as the young group, while 18-month-old mice were selected as the old group, and sodium hydrosulfide (NaHS) was injected intraperitoneally from 15 months old until 18 months old as the old + NaHS group. Plasma MMP-9 content was detected using Elisa, plasma H2S content, cardiac H2S content, and cystathionine gamma-lyase (CSE) activity were detected using LC/MC, and cardiac function was detected using echocardiography. Heart structure was assessed using hematoxylin and eosin staining, Masone staining was used to detect the degree of cardiac fibrosis, while western blot was used to detect the expression of MMP-9, CSE, and aging marker proteins. Knockdown of MMP-9 and CSE in H9c2 cells using small interfering RNA was carried out to determine the upstream-downstream relationship between MMP-9 and CSE. RESULTS: H2S content in the plasma of healthy individuals decreases with escalating age, whereas MMP-9 level rises with age progression. Aging leads to a decrease in H2S levels in the heart and plasma of mice, severe impairment of cardiac diastolic function, interstitial relaxation, and fibrosis of the heart. Supplementing with exogenous H2S can improve these phenomena. CONCLUSION: H2S maintains the structure and function of the heart by inhibiting the expression of MMP-9 during the aging process.

Butyrate attenuates sympathetic activation in rats with chronic heart failure by inhibiting microglial inflammation in the paraventricular nucleus.

Sympathetic activation is a hallmark of heart failure and the underlying mechanism remains elusive. Butyrate is generated by gut microbiota and influences numerous physiological and pathological processes in the host. The present study aims to investigate whether the intestinal metabolite butyrate reduces sympathetic activation in rats with heart failure (HF) and the underlying mechanisms involved. Sprague-Dawley rats (220‒250 g) are anaesthetized with isoflurane, and the left anterior descending artery is ligated to model HF. Then, the rats are treated with or without butyrate sodium (NaB, a donor of butyrate, 10 g/L in water) for 8 weeks. Blood pressure and renal sympathetic nerve activity (RSNA) are recorded to assess sympathetic outflow. Cardiac function is improved (mean ejection fraction, 22.6%±4.8% vs 38.3%±5.3%; P<0.05), and sympathetic activation is decreased (RSNA, 36.3%±7.9% vs 23.9%±7.6%; P<0.05) in HF rats treated with NaB compared with untreated HF rats. The plasma and cerebrospinal fluid levels of norepinephrine are decreased in HF rats treated with NaB. The infusion of N-methyl-D-aspartic acid (NMDA) into the paraventricular nucleus (PVN) of the hypothalamus of HF model rats increases sympathetic nervous activity by upregulating the NMDA receptor. Microglia polarized to the M2 phenotype and inflammation are markedly attenuated in the PVN of HF model rats after NaB administration. In addition, HF model rats treated with NaB exhibit enhanced intestinal barrier function and increased levels of GPR109A, zona occludens-1 and occludin, but decreased levels of lipopolysaccharide-binding protein and zonulin. In conclusion, butyrate attenuates sympathetic activation and improves cardiac function in rats with HF. The improvements in intestinal barrier function, reductions in microglia-mediated inflammation and decreases in NMDA receptor 1 expression in the PVN are all due to the protective effects of NaB.

Hydrogen sulfide ameliorates endothelial dysfunction in aging arteries by regulating ferroptosis.

Aging causes vascular endothelial dysfunction. We aimed to investigate the causes of vascular endothelial dysfunction during aging using plasma and renal arteries from patients who underwent nephrectomy and animal models. The results showed that the endogenous H2S-producing enzyme cystathione-γ-lyase (CSE) protein expression was downregulated in renal artery tissue, plasma H2S levels were reduced. Moreover, elevated lipid peroxidation and iron accumulation levels led to ferroptosis and endothelial diastolic function in the renal arteries was impaired in the elderly group. H2S enhanced the endogenous CSE expression in the elderly group, promoted endogenous H2S production, decreased lipid peroxide expression, and inhibited ferroptosis, which in turn improved vascular endothelial function in the elderly group. In animal models, we also observed the same results. In addition, we applied NaHS, Ferrostatin-1 (ferroptosis inhibitor) and erastin (ferroptosis inducer) to incubate renal arteries of SD rats. The results showed that NaHS enhanced ferroptosis related proteins expression, inhibited ferroptosis and improved vascular endothelial function. We demonstrated that endothelial dysfunction associated with aging is closely related to reduced endogenous H2S levels and ferroptosis in vascular endothelial cells. Notably, H2S reduced lipid peroxidation levels in vascular endothelial cells, inhibited ferroptosis in vascular endothelial cells, and improved endothelial dysfunction.

Feedback Interaction Between Apelin and Endoplasmic Reticulum Stress in the Rat Myocardium.

ABSTRACT: Apelin is an endogenous active peptide, playing a crucial role in regulating cardiovascular homeostasis. This study aimed to investigate the interaction between apelin and endoplasmic reticulum stress (ERS). Tunicamycin (Tm) and dithiothreitol (DTT) were used to induce ERS in the ex vivo cultured myocardium of rats. Myocardial injury was determined by the activities of lactate dehydrogenase and creatine kinase-MB in the culture medium. The protein levels of an ERS-associated molecule, apelin, and its receptor angiotensin domain type 1 receptor-associated proteins (APJ) in the myocardium were determined by western blot analysis. The level of apelin in the culture medium was determined by enzyme immunoassay. Administration of Tm and DTT triggered ERS activation and myocardial injury, and led to a decrease in protein levels of apelin and APJ, in a dose-dependent manner. Integrated stress response inhibitor, an inhibitor of eukaryotic initiation factor 2α phosphorylation that is commonly used to prevent activation of protein kinase R-like ER kinase cascades, blocked ERS-induced myocardial injury and reduction of apelin and APJ levels. The ameliorative effect of integrated stress response inhibitor was partially inhibited by [Ala]-apelin-13, an antagonist of APJ. Furthermore, apelin treatment inhibited activation of the 3 branches of ERS induced by Tm and DTT in a dose-dependent manner, thereby preventing Tm-induced or DTT-induced myocardial injury. The negative feedback regulation between ERS activation and apelin/APJ suppression might play a critical role in myocardial injury. Restoration of apelin/APJ signaling provides a potential target for the treatment and prevention of ERS-associated tissue injury and diseases.

Comparison and improvement of RNA extraction methods in Sargassum (Phaeophyta).

Sargassum (Sargassaceae) is widely distributed globally and plays an important role in regulating climate change, but the landscape of genomes and transcripts is less known. High-quality nucleic acids are the basis for molecular biology experiments such as high-throughput sequencing. Although extensive studies have documented methods of RNA extraction, these methods are not very applicable to Sargassum, which contains high levels of polysaccharides and polyphenols. To find a suitable method to improve the quality of RNA extracted, we compared and modified several popular RNA extraction methods and screened one practical method with three specific Sargassum spp. The results showed that three CTAB methods (denoted as Methods 1, 2, and 3) and the RNAprep Pure Plant Kit (denoted as Method 4) could, with slight modifications, effectively isolate RNA from Sargassum species, except for Method 4 used with S. fusiforme. By performing further screening, we determined Method 4 was the best choice for S. hemiphyllum and S. henslowianum, as revealed by RNA yields, RNA Integrity Number (RIN), extraction time, and unigene mapped ratio. For S. fusiforme, Methods 1, 2, and 3 showed no obvious differences among the yields, quality, or time to perform. In addition, one other method was tested, but we found the quality of the RNA extracted by TRIzol reagent methods (denoted as Method 5) performed the worst when compared with the above four methods. Therefore, our study provides four suitable methods for RNA extraction in Sargassum and is essential for future genetic exploration of Sargassum.

Inflammatory bowel disease and the associated risk of dry eye and ocular surface injury: a nationwide matched cohort study.

BACKGROUND: Inflammatory bowel disease (IBD) is associated with lacrimal gland dysfunction and ocular inflammation. The objective of this research was to elucidate the temporal relationships between IBD, dry eye disease (DED), and corneal surface damage. METHODS: In a matched nationwide cohort study, we evaluated the risk of DED and corneal surface damage associated with IBD. Multivariable Cox proportional hazards regression analyses were implemented to estimate the risk of ocular complications. RESULTS: A total of 54,293 matched pairs were included for analyses. The median follow-up time was 8.3 years (interquartile range: 5.5 - 10.5). The period incidence of DED was 8.18 and 5.42 per 1000 person-years in the IBD and non-IBD groups, respectively. After adjusting for confounders, statistically significant associations were found between IBD and DED [adjusted hazard ratio (aHR): 1.43, 95% confidence interval (CI): 1.35 - 1.51, p < 0.0001], Sjögren's syndrome-related (aHR: 1.67, 95% CI:1.46 - 1.90, p < 0.0001) and non-Sjögren's syndrome-related subtypes (aHR: 1.38, 95% CI: 1.30 - 1.46, p < 0.0001). Furthermore, increased risks of corneal surface damage (aHR: 1.13, 95% CI: 1.03 - 1.24, p = 0.0094) among the patients with IBD were observed when compared with the controls. Other independent factors associated with corneal surface damage were age (aHR: 1.003), sex (male vs. female, aHR: 0.85), and monthly insurance premium (501-800 vs. 0-500 U.S. dollars, aHR: 1.45; ≥ 801 vs. 0-500 U.S. dollars, aHR: 1.32). CONCLUSIONS: Our results suggested that IBD was an independent risk factor for DED and ocular surface damage. Clinical strategies are needed to prevent visual impairment or losses in these susceptible patients.

Hydrogen sulfide ameliorates senescence in vascular endothelial cells through ameliorating inflammation and activating PPARδ/SGLT2/STAT3 signaling pathway.

Mounting evidence demonstrates that hydrogen sulfide (H 2S) promotes anti-inflammatory molecules and inhibits pro-inflammatory cytokines in endothelial cells (ECs). This study aims to investigate the favorable action of H 2S on endothelial function in senescence by inhibiting the production of inflammatory molecules. Senescent ECs exhibit a reduction in H 2S, endothelial nitric oxide synthase (eNOS) and peroxisome proliferator-activated receptor δ (PPARδ), coupled with increased inflammatory molecules, sodium glucose transporter type 2 (SGLT2) and phosphorylation of STAT3, which could be reversed by the administration of a slow but sustained release agent of H 2S, GYY4137. Decreased production of eNOS and upregulated p-STAT3 and SGLT2 levels in senescent ECs are reversed by replenishment of the SGLT2 inhibitor EMPA and the PPARδ agonist GW501516. The PPARδ antagonist GSK0660 attenuates eNOS expression and increases the production of p-STAT3 and SGLT2. However, supplementation with GYY4137 has no beneficial effect on GSK0660-treated ECs. GYY4137, GW501516 and EMPA preserve endothelial-dependent relaxation (EDR) in D-gal-treated aortae, while GSK0660 destroys aortic relaxation even with GYY4137 supplementation. In summary, senescent ECs manifest aggravated the expressions of the inflammatory molecules SGLT2 and p-STAT3 and decreased the productions of PPARδ, eNOS and CSE. H 2S ameliorates endothelial dysfunction through the anti-inflammatory effect of the PPARδ/SGLT2/p-STAT3 signaling pathway in senescent ECs and may be a potential therapeutic target for anti-ageing treatment.

Ultrasensitive Detection of Interleukin 6 by Using Silicon Nanowire Field-Effect Transistors.

Interleukin 6 (IL-6) has been regarded as a biomarker that can be applied as a predictor for the severity of COVID-19-infected patients. The IL-6 level also correlates well with respiratory dysfunction and mortality risk. In this work, three silanization approaches and two types of biorecognition elements were used on the silicon nanowire field-effect transistors (SiNW-FETs) to investigate and compare the sensing performance on the detection of IL-6. Experimental data revealed that the mixed-SAMs-modified silica surface could have superior surface morphology to APTES-modified and APS-modified silica surfaces. According to the data on detecting various concentrations of IL-6, the detection range of the aptamer-functionalized SiNW-FET was broader than that of the antibody-functionalized SiNW-FET. In addition, the lowest concentration of valid detection for the aptamer-functionalized SiNW-FET was 2.1 pg/mL, two orders of magnitude lower than the antibody-functionalized SiNW-FET. The detection range of the aptamer-functionalized SiNW-FET covered the concentration of IL-6, which could be used to predict fatal outcomes of COVID-19. The detection results in the buffer showed that the anti-IL-6 aptamer could produce better detection results on the SiNW-FETs, indicating its great opportunity in applications for sensing clinical samples.

Thriving psychological well-being in undergraduate nursing student: a grounded theory study with the life grid approach.

BACKGROUND: Psychological well-being (PWB) plays a vital role in successful adaptation to the Bachelor of Nursing journey and affects career development. However, there is little known about the functional and social processes associated with enhancing well-being specific to the subjective perspective of nursing students. AIM: To investigate how nursing students promote their psychological well-being to conceptualize thriving psychological well-being. METHOD: This qualitative study analyzed and reviewed a life grid and semi-structured in-depth interviews of 20 Chinese Nursing graduates by investigators and participants, following Charmaz's constructivist grounded theory. The constant comparative method was used to analyze data. This study took place between 2020 and 2022. RESULTS: All participants experienced fluctuations in psychological well-being. This study identified a new understanding of how nursing students enhance their psychological well-being. Thriving awareness was co-constructed as the core category and based on the relationship with a supportive environment, the thriving psychological well-being of nursing students is conceptualized. CONCLUSIONS: It is imperative to enhance the psychological counseling and support for nursing students during their clinical placements, during the period just entering university as well as after repeated outbreaks of COVID-19. Nursing educators and administrators could develop appropriate educational programs and interventions based on the theoretical model-Thriving psychological well-being.

Identification of Montelukast as flavivirus NS2B-NS3 protease inhibitor by inverse virtual screening and experimental validation.

Flavivirus, such as Dengue Virus (DENV) and Zika virus (ZIKV), infects millions of people and cause the death of thousands of people every year. Despite many efforts, there is no approved anti-flaviviral treatment available. In particular, some antiflavivirus compounds were investigated the cellular activities of DENV and ZIKV, but lacking the exploration of specific target enzyme, thereby resulting in the hindrance of structure-based drug design. One example is Montlukast, which was found to inhibit the replicon replication in DENV and ZIKV infected cells, with EC50 values as 1.03 µM (DENV) and 1.14 µM (ZIKV), while the underlying mechanism remains unclear. In our study, the inhibitory mechanisms of Montelukast against the replicon replication of DENV and ZIKV infected cells were studied by using in silico approaches including inverse virtual screening (IVS), molecular dynamics (MD) simulations and binding free energy calculation, and validated through in vitro protease assay, confirming Montelukast could bind to NS2B-NS3 proteases of DENV and ZIKV as a competitive inhibitor (IC50 for DENV: 25.65 µM, for ZIKV: 15.57 µM). Moreover, Montelukast has no potential off-target effect on NS2B-NS3 protease from thrombin and trypsin inhibitory assay. Overall, Montelukast may be used as a potential candidate to block NS2B-NS3 protease as well as lead for structural modification.

Predicting nursing students' psychological well-being: network analysis based on a model of thriving through relationships.

BACKGROUND: Psychological well-being plays a vital role in nursing students' mental health and affects their decisions to stay in the nursing profession, particularly during the COVID-19 outbreak. Close relationships are undeniably linked to psychological well-being, but it is unknown how the specific pathways through which close relationships are related to each other and which are most strongly linked to nursing students' psychological well-being. AIMS: To explore the network structure, central and bridge factors among well-being characteristics, and predictors based on a model of thriving through relationships. METHODS: A cross-sectional research design was used with a sample of undergraduate nursing students (531 participants from the Southwest part of China). We used a network model to analyze the network structure of perceived social support, mindfulness, self-integrity, self-compassion, professional self-concept, savoring, intentional self-regulation, non-relational self-expansion, relational self-expansion, attachment insecurity, and psychological well-being. RESULTS:  A highly interconnected network of psychological well-being featured predictors and traits were formed. Node 8 (self-kindness), node 9 (self-judgment), and node 23 (non-relational self-expansion) were the predictors with the highest centrality in the network. Perceived social support and professional self-concept were most central in linking predictors to psychological well-being traits. Attachment insecurity was a non-supportive factor for predicting psychological well-being among female nursing students. CONCLUSIONS: Interventions based on these supportive/non-supportive predictors, which operate on different psychological levels, hold promise to achieve positive effects on psychological well-being among nursing students.

Psychometric properties and latent profile analysis of the Nursing Brand Image Scale: a methodological study in the Chinese context.

AIMS: To translate the U.S. version of the Nursing Brand Image Scale to Chinese (NBIS-C) and evaluate its psychometric properties when administered to a national sample of Chinese nurses, and identify nursing brand image profiles in Chinese nurses. DESIGN: A cross-sectional study was conducted to validate the NBIS-C among nurses in China. METHODS: The psychometric properties of the NBIS-C were tested in accordance with the COSMIN checklist. The reliability, validity, and responsiveness of the 42-item NBIS-C were examined in a national sample of 759 nurses recruited from 29 Chinese provinces. Latent Profile Analyses (LPA) were conducted to reveal nurses' perceptions of the brand image of nursing. RESULTS: Results of this study demonstrated acceptable validity (content validity, structural validity, and construct validity), reliability (internal consistency and test-retest reliability), adequate responsiveness, and no floor/ceiling effect of the NBIS-C. LPA yielded five subgroups: Integrated, Traditional, Subordinate, Creative and Leader. CONCLUSION: The psychometric properties of the NBIS-C are suitable for assessing the image of nursing among Chinese nurses. Future studies with a larger, more diverse sample are recommended. Although the role of nurses in China has evolved, nurses in general have failed to communicate a consistent, positive, and accurate brand image for the nursing profession.

Inhibition of endoplasmic reticulum stress mediates the ameliorative effect of apelin on vascular calcification.

AIMS: Apelin is the endogenous ligand of G protein-coupled receptor APJ and play an important role in the regulation of cardiovascular homeostasis. We aimed to investigate whether apelin ameliorates vascular calcification (VC) by inhibition of endoplasmic reticulum stress (ERS). METHODS AND RESULTS: VC model in rats was induced by nicotine plus vitamin D, while calcification of vascular smooth muscle cell (VSMC) was induced by beta-glycerophosphate. Alizarin Red S staining showed dramatic calcium deposition in the aorta of rats with VC, while calcium contents and ALP activity also increased in calcified aorta. Protein levels of apelin and APJ were decreased in the calcified aorta. In rats with VC, apelin treatment significantly ameliorated aortic calcification, compliance and stimulation of ERS. The ameliorative effect of apelin on VC and ERS was also observed in calcified VSMCs. ERS stimulator (tunicamycin or DTT) blocked the beneficial effect of apelin. Apelin treatment activated the PI3K/Akt signaling, blockage of which by wortmannin or inhibitor IV prevented the ameliorative effect of apelin, while ERS inhibitor 4-PBA rescued the blockade effect of wortmannin. Akt-induced GSK inhibition prevented the phosphorylation of PERK and IRE1, and the activation of these two major ERS branches. F13A blocked the ameliorative effect of apelin on VC and ERS, which was reversed by treatment with 4-PBA or Akt activator SC79 CONCLUSIONS: Apelin ameliorated VC by binding to APJ and then prevented ERS activation by stimulating Akt signaling. These results might provide new target for therapy and prevention of VC.

RhANP attenuates endotoxin-derived cognitive dysfunction through subdiaphragmatic vagus nerve-mediated gut microbiota-brain axis.

BACKGROUND: Atrial natriuretic peptide (ANP) secreted from atrial myocytes is shown to possess anti-inflammatory, anti-oxidant and immunomodulatory effects. The aim of this study is to assess the effect of ANP on bacterial lipopolysaccharide (LPS)-induced endotoxemia-derived neuroinflammation and cognitive impairment. METHODS: LPS (5 mg/kg) was given intraperitoneally to mice. Recombinant human ANP (rhANP) (1.0 mg/kg) was injected intravenously 24 h before and/or 10 min after LPS injection. Subdiaphragmatic vagotomy (SDV) was performed 14 days before LPS injection or 28 days before fecal microbiota transplantation (FMT). ANA-12 (0.5 mg/kg) was administrated intraperitoneally 30 min prior to rhANP treatment. RESULTS: LPS (5.0 mg/kg) induced remarkable splenomegaly and an increase in the plasma cytokines at 24 h after LPS injection. There were positive correlations between spleen weight and plasma cytokines levels. LPS also led to increased protein levels of ionized calcium-binding adaptor molecule (iba)-1, cytokines and inducible nitric oxide synthase (iNOS) in the hippocampus. LPS impaired the natural and learned behavior, as demonstrated by an increase in the latency to eat the food in the buried food test and a decrease in the number of entries and duration in the novel arm in the Y maze test. Combined prophylactic and therapeutic treatment with rhANP reversed LPS-induced splenomegaly, hippocampal and peripheral inflammation as well as cognitive impairment. However, rhANP could not further enhance the protective effects of SDV on hippocampal and peripheral inflammation. We further found that PGF mice transplanted with fecal bacteria from rhANP-treated endotoxemia mice alleviated the decreased protein levels of hippocampal polyclonal phosphorylated tyrosine kinase receptor B (p-TrkB), brain-derived neurotrophic factor (BDNF) and cognitive impairment, which was abolished by SDV. Moreover, TrkB/BDNF signaling inhibitor ANA-12 abolished the improving effects of rhANP on LPS-induced cognitive impairment. CONCLUSIONS: Our results suggest that rhANP could mitigate LPS-induced hippocampal inflammation and cognitive dysfunction through subdiaphragmatic vagus nerve-mediated gut microbiota-brain axis.

Inhibitory effect on SARS-CoV-2 infection of neferine by blocking Ca2+ -dependent membrane fusion.

The coronavirus disease 2019 (COVID-19) pandemic has focused attention on the need to develop effective therapeutics against the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and also against other pathogenic coronaviruses. In this study, we report on a kind of bisbenzylisoquinoline alkaloid, neferine, as a pan-coronavirus entry inhibitor. Neferine effectively protected HEK293/hACE2 and HuH7 cell lines from infection by different coronaviruses pseudovirus particles (SARS-CoV-2, SARS-CoV-2 [D614G, N501Y/D614G, 501Y.V1, 501Y.V2, 501Y.V3 variants], SARS-CoV, MERS-CoV) in vitro, with median effect concentration (EC50 ) of 0.13-0.41 µM. Neferine blocked host calcium channels, thus inhibiting Ca2+ -dependent membrane fusion and suppressing virus entry. This study provides experimental data to support the fact that neferine may be a promising lead for pan-coronaviruses therapeutic drug development.

Apelin ameliorated acute heart failure via inhibiting endoplasmic reticulum stress in rabbits.

This study aimed to investigate whether inhibition of endoplasmic reticulum stress (ERS) mediated the ameliorative effect of apelin on acute heart failure (AHF). Rabbit model of AHF was induced by sodium pentobarbital. Cardiac dysfunction and injury were detected in the rabbit models of AHF, including impaired hemodynamic parameters and increased levels of CK-MB and cTnI. Apelin treatment dramatically improved cardiac impairment caused by AHF. ERS, indexed by increased GRP78, CHOP, and cleaved-caspase12 protein levels, was simultaneously attenuated by apelin. Apelin also could ameliorate increased protein levels of cleaved-caspase3 and Bax, and improved decreased protein levels of Bcl-2. Two common ERS stimulators, tunicamycin (Tm) and dithiothreitol (DTT) blocked the ameliorative effect of apelin on AHF. Phosphorylated Akt levels increased after apelin treatment in the rabbit models of AHF. The Akt signaling inhibitors wortmannin and LY294002 could block the cardioprotective effect of apelin, which could be relieved by ERS inhibitor 4-phenyl butyric acid (4-PBA). The aforementioned beneficial effects of apelin could all be blocked by APJ receptor antagonist F13A. 4-PBA and SC79, an Akt activator, can restore the ameliorative effect of apelin on AHF blocked by F13A. Apelin treatment dramatically ameliorated cardiac impairment caused by AHF, which might be mediated by APJ/Akt/ERS signaling pathway. These results will shed new light on AHF therapy.

The Antioxidant Phytochemical Schisandrin A Promotes Neural Cell Proliferation and Differentiation after Ischemic Brain Injury.

Schisandrin A (SCH) is a natural bioactive phytonutrient that belongs to the lignan derivatives found in Schisandra chinensis fruit. This study aims to investigate the impact of SCH on promoting neural progenitor cell (NPC) regeneration for avoiding stroke ischemic injury. The promoting effect of SCH on NPCs was evaluated by photothrombotic model, immunofluorescence, cell line culture of NPCs, and Western blot assay. The results showed that neuron-specific class III beta-tubulin (Tuj1) was positive with Map2 positive nerve fibers in the ischemic area after using SCH. In addition, Nestin and SOX2 positive NPCs were significantly (p < 0.05) increased in the penumbra and core. Further analysis identified that SCH can regulate the expression level of cell division control protein 42 (Cdc42). In conclusion, our findings suggest that SCH enhanced NPCs proliferation and differentiation possible by Cdc42 to regulated cytoskeletal rearrangement and polarization of cells, which provides new hope for the late recovery of stroke.

Hydrogen sulfide attenuates cardiac injury in takotsubo cardiomyopathy by alleviating oxidative stress.

Takotsubo cardiomyopathy (TCM) is characterized by transient left ventricular apical ballooning with the absence of coronary occlusion, which is an acute cardiac syndrome with substantial morbidity and mortality. It was reported that reduced endogenous hydrogen sulfide (H2S) levels may be related to various heart diseases. The present study investigated the mechanism by which H2S administration modulates and protects cardiac function in TCM rats. In order to establish a TCM model, Sprague Dawley (SD) rats were injected with a single dose of ß-adrenergic agonist isoprenaline (ISO). We found that ISO induced cardiac dysfunction, which was characterized by a significant decrease in left ventricular systolic pressure (LVSP), maximum contraction velocity (+dp/dtmax), maximum relaxation velocity (-dp/dtmax) and increased left ventricular end-diastolic pressure (LVEDP). Accordingly, we found that plasma and heart tissue H2S levels in TCM rats decreased significantly, and cardiac cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST) expression were lower. Moreover, cardiac dysfunction in TCM was associated with oxidative stress response and reactive oxygen species (ROS) formation. NADPH Oxidase 4 (NOX4) and p67 protein expressions significantly increased in TCM cardiac tissues. In addition, Sodium hydrosulfide (NaHS) ameliorated ISO-induced cardiac dysfunction and reversed ISO-induced oxidative stress. This study revealed that H2S exerted cardioprotective effects by reducing NADPH oxidase, which reduced ROS formation and prevented oxidative stress. Our study provided novel evidence that H2S is protective in myocardial dysfunction in TCM rats and could be a therapeutic target for alleviating ß-adrenergic system overstimulation-induced cardiovascular dysfunction.

Gene transfer of cystathionine ß-synthase into RVLM increases hydrogen sulfide-mediated suppression of sympathetic outflow via KATP channel in normotensive rats.

Hydrogen sulfide has been shown to have a sympathoinhibitory effect in the rostral ventrolateral medulla (RVLM). The present study examined the function of cystathionine ß-synthase (CBS)/hydrogen sulfide system in the RVLM, which plays a crucial role in the control of blood pressure and sympathetic nerve activity. Adenovirus vectors encoding CBS (AdCBS) or enhanced green fluorescent protein (AdEGFP) were transfected into the RVLM in normotensive rats. Identical microinjection of AdCBS into the RVLM had no effect on systolic blood pressure and heart rate (HR) in conscious rats. Acute experiments were performed at day 7 after gene transfer in anesthetized rats. Microinjection of the CBS inhibitors hydroxylamine (HA) or amino-oxyacetate into the RVLM produced an increase in the renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP), and HR. There was a potentiation of the increases in RSNA, MAP, and HR because of the CBS inhibitors in AdCBS-injected rats compared with AdEGFP-injected rats. Pretreatment with pinacidil, a ATP-sensitive potassium (KATP) channel activator, abolished the effects of HA in two groups. Microinjection of glibenclamide, a KATP channel blocker, produced increases in RSNA, MAP, and HR in AdCBS-injected rats. No changes in behavior were observed in AdEGFP-injected rats. Furthermore, Western blot analysis indicated an increase in the expression of sulfonylurea receptor 2 and inward rectifier K(+) 6.1 in AdCBS-injected rats. These results suggest that the increase in KATP channels in the RVLM may be responsible for the greater sympathetic outflow and pressor effect of HA in AdCBS-injected rats compared with AdEGFP-injected rats.