Inhibition of ferroptosis by icariin treatment attenuates excessive ethanol consumption-induced atrial remodeling and susceptibility to atrial fibrillation, role of SIRT1.

Ferroptosis contributes to the pathogenesis of atrial fibrillation (AF), although the mechanisms are still largely uncovered. The current study was designed to explore the pharmacological effects of icariin against ethanol-induced atrial remodeling, if any, and the mechanisms involved with a focus on SIRT1 signaling. Excessive ethanol-treated animals were administered with Ferrostatin-1, Erastin or icariin to evaluate the potential effects of icariin or ferroptosis. Then, the underling mechanisms was further explored in the in vitro experiments using HL-1 atrial myocytes. Excessive ethanol administration caused significant atrial damage as evidenced by increased susceptibility to AF, altered atrial conduction pattern, atrial enlargement, and enhanced fibrotic markers. These detrimental effects were reversed by Ferrostatin-1 or icariin treatment, while Erastin co-administration markedly abolished the beneficial actions conferred by icariin. Mechanistically, ethanol-treated atria exhibited markedly up-regulated pro-ferroptotic protein (PTGS2, ACSL4, P53) and suppressed anti-ferroptotic molecules (GPX4, FTH1). Icariin treatment inhibited ethanol-induced atrial ferroptosis by reducing atrial mitochondrial damage, ROS accumulation and iron overload. Interestingly, the in vivo and in vitro data showed that icariin activated atrial SIRT1-Nrf-2-HO-1 signaling pathway, while EX527 not only reversed these effects, but also abolished the therapeutic effects of icariin. Moreover, the stimulatory effects on GPX4, SLC7A11 and the suppressive effects on ACSL4, P53 conferred by icariin were blunted by EX527 treatment. These data demonstrate that ferroptosis plays a causative role in the pathogenesis of ethanol-induced atrial remodeling and susceptibility to AF. Icariin protects against atrial damage by inhibiting ferroptosis via SIRT1 signaling. Its role as a prophylactic/therapeutic drug deserves further clinical study.

Palmitic acid induces GSDMD-mediated pyroptosis in periodontal ligament cells via the NF-κB pathway.

OBJECTIVE: Obesity can affect periodontal tissues and exacerbate periodontitis. Pyroptosis, a newly identified type of inflammatory cell death, is involved in the development of periodontal inflammation. The saturated fatty acid palmitic acid (PA) is elevated in obese patients. The effect of PA on pyroptosis in periodontal ligament cells (PDLCs) and its underlying mechanisms remain unknown. MATERIALS AND METHODS: Human PDLCs were isolated from healthy individuals and cultured for experiments. The effects of PA on PDLC pyroptosis and the underlying mechanisms were examined by transmission electron microscopy, quantitative real-time PCR and western blotting. RESULTS: The morphology of PDLCs in the PA group indicated pyroptotic characteristics, including swollen cells, plasma membrane rupture and changes in subcellular organelles. PA induced inflammatory responses in PDLCs, as indicated by an increase in IL-1ß in the cell culture supernatant. Furthermore, we found that the pyroptosis-related proteins caspase-1, caspase-4 and GSDMD were involved in PA-induced cell death. GSDMD and caspase-4 inhibitors alleviated pyroptotic death of PDLCs. Moreover, PA promoted NF-κB P65 phosphorylation. A NF-κB inhibitor decreased IL-1ß expression and partly rescued cell death induced by PA. CONCLUSION: PA activated the NF-κB pathway and induced the inflammatory response in PDLCs. Caspase-4/GSDMD mediated PDLC pyroptosis induced by PA.

Melatonin attenuates diabetic cardiomyopathy and reduces myocardial vulnerability to ischemia-reperfusion injury by improving mitochondrial quality control: Role of SIRT6.

Targeting mitochondrial quality control with melatonin has been found promising for attenuating diabetic cardiomyopathy (DCM), although the underlying mechanisms remain largely undefined. Activation of SIRT6 and melatonin membrane receptors exerts cardioprotective effects while little is known about their roles during DCM. Using high-fat diet-streptozotocin-induced diabetic rat model, we found that prolonged diabetes significantly decreased nocturnal circulatory melatonin and heart melatonin levels, reduced the expressions of cardiac melatonin membrane receptors, and decreased myocardial SIRT6 and AMPK-PGC-1α-AKT signaling. 16 weeks of melatonin treatment inhibited the progression of DCM and the following myocardial ischemia-reperfusion (MI/R) injury by reducing mitochondrial fission, enhancing mitochondrial biogenesis and mitophagy via re-activating SIRT6 and AMPK-PGC-1α-AKT signaling. After the induction of diabetes, adeno-associated virus carrying SIRT6-specific small hairpin RNA or luzindole was delivered to the animals. We showed that SIRT6 knockdown or antagonizing melatonin receptors abolished the protective effects of melatonin against mitochondrial dysfunction as evidenced by aggravated mitochondrial fission and reduced mitochondrial biogenesis and mitophagy. Additionally, SIRT6 shRNA or luzindole inhibited melatonin-induced AMPK-PGC-1α-AKT activation as well as its cardioprotective actions. Collectively, we demonstrated that long-term melatonin treatment attenuated the progression of DCM and reduced myocardial vulnerability to MI/R injury through preserving mitochondrial quality control. Melatonin membrane receptor-mediated SIRT6-AMPK-PGC-1α-AKT axis played a key role in this process. Targeting SIRT6 with melatonin treatment may be a promising strategy for attenuating DCM and reducing myocardial vulnerability to ischemia-reperfusion injury in diabetic patients.

Melatonin protects diabetic heart against ischemia-reperfusion injury, role of membrane receptor-dependent cGMP-PKG activation.

It has been demonstrated that the anti-oxidative and cardioprotective effects of melatonin are, at least in part, mediated by its membrane receptors. However, the direct downstream signaling remains unknown. We previously found that melatonin ameliorated myocardial ischemia-reperfusion (MI/R) injury in diabetic animals, although the underlying mechanisms are also incompletely understood. This study was designed to determine the role of melatonin membrane receptors in melatonin's cardioprotective actions against diabetic MI/R injury with a focus on cGMP and its downstream effector PKG. Streptozotocin-induced diabetic Sprague-Dawley rats and high-glucose medium-incubated H9c2 cardiomyoblasts were utilized to determine the effects of melatonin against MI/R injury. Melatonin treatment preserved cardiac function and reduced oxidative damage and apoptosis. Additionally, melatonin increased intracellular cGMP level, PKGIα expression, p-VASP/VASP ratio and further modulated myocardial Nrf-2-HO-1 and MAPK signaling. However, these effects were blunted by KT5823 (a selective inhibitor of PKG) or PKGIα siRNA except that intracellular cGMP level did not changed significantly. Additionally, our in vitro study showed that luzindole (a nonselective melatonin membrane receptor antagonist) or 4P-PDOT (a selective MT2 receptor antagonist) not only blocked the cytoprotective effect of melatonin, but also attenuated the stimulatory effect of melatonin on cGMP-PKGIα signaling and its modulatory effect on Nrf-2-HO-1 and MAPK signaling. This study showed that melatonin ameliorated diabetic MI/R injury by modulating Nrf-2-HO-1 and MAPK signaling, thus reducing myocardial apoptosis and oxidative stress and preserving cardiac function. Importantly, melatonin membrane receptors (especially MT2 receptor)-dependent cGMP-PKGIα signaling played a critical role in this process.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-D-glucoside protects murine hearts against ischemia/reperfusion injury by activating Notch1/Hes1 signaling and attenuating endoplasmic reticulum stress.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-D-glucoside (TSG) is a water-soluble active component extracted from Polygonum multiflorum Thunb. A number of studies demonstrate that TSG exerts cardioprotective effects. Since endoplasmic reticulum (ER) stress plays a key role in myocardial ischemia/reperfusion (MI/R)-induced cell apoptosis, we sought to determine whether modulation of the ER stress during MI/R injury was involved in the cardioprotective action of TSG. Male mice were treated with TSG (60 mg·kg-1·d-1, ig) for 2 weeks and then were subjected to MI/R surgery. Pre-administration of TSG significantly improved post-operative cardiac function, and suppressed MI/R-induced myocardial apoptosis, evidenced by the reduction in the myocardial apoptotic index, serum levels of LDH and CK after 6 h of reperfusion. TSG (0.1-1000 µmol/L) did not affect the viability of cultured H9c2 cardiomyoblasts in vitro, but pretreatment with TSG dose-dependently decreased simulated ischemia/reperfusion (SIR)-induced cell apoptosis. Furthermore, both in vivo and in vitro studies revealed that TSG treatment activated the Notch1/Hes1 signaling pathway and suppressed ER stress, as evidenced by increasing Notch1, Notch1 intracellular domain (NICD), Hes1, and Bcl-2 expression levels and by decreasing p-PERK/PERK ratio, p-eIF2α/eIF2α ratio, and ATF4, CHOP, Bax, and caspase-3 expression levels. Moreover, the protective effects conferred by TSG on SIR-treated H9c2 cardiomyoblasts were abolished by co-administration of DAPT (the Notch1 signaling inhibitor). In summary, TSG ameliorates MI/R injury in vivo and in vitro by activating the Notch1/Hes1 signaling pathway and attenuating ER stress-induced apoptosis.

Berberine protects rat heart from ischemia/reperfusion injury via activating JAK2/STAT3 signaling and attenuating endoplasmic reticulum stress.

AIM: Berberine (BBR), an isoquinoline-derived alkaloid isolated from Rhizoma coptidis, exerts cardioprotective effects. Because endoplasmic reticulum (ER) stress plays a pivotal role in myocardial ischemia/reperfusion (MI/R)-induced apoptosis, it was interesting to examine whether the protective effects of BBR resulted from modulating ER stress levels during MI/R injury, and to define the signaling mechanisms in this process. METHODS: Male rats were treated with BBR (200 mg · kg(-1) · d(-1), ig) for 2 weeks, and then subjected to MI/R surgery. Cardiac dimensions and function were assessed using echocardiography. Myocardial infarct size and apoptosis was examined. Total serum LDH levels and CK activities, superoxide production, MDA levels and the antioxidant SOD activities in heart tissue were determined. An in vitro study was performed on cultured rat embryonic myocardium-derived cells H9C2 exposed to simulated ischemia/reperfusion (SIR). The expression of apoptotic, ER stress-related and signaling proteins were assessed using Western blot analyses. RESULTS: Pretreatment with BBR significantly reduced MI/R-induced myocardial infarct size, improved cardiac function, and suppressed myocardial apoptosis and oxidative damage. Furthermore, pretreatment with BBR suppressed MI/R-induced ER stress, evidenced by down-regulating the phosphorylation levels of myocardial PERK and eIF2α and the expression of ATF4 and CHOP in heart tissues. Pretreatment with BBR also activated the JAK2/STAT3 signaling pathway in heart tissues, and co-treatment with AG490, a specific JAK2/STAT3 inhibitor, blocked not only the protective effects of BBR, but also the inhibition of BBR on MI/R-induced ER stress. In H9C2 cells, treatment with BBR (50 µmol/L) markedly reduced SIR-induced cell apoptosis, oxidative stress and ER stress, which were abolished by transfection with JAK2 siRNA. CONCLUSION: BBR ameliorates MI/R injury in rats by activating the AK2/STAT3 signaling pathway and attenuating ER stress-induced apoptosis.

[Proanthocyanidin protects H9C2 cells against hypoxia/reoxygenation injury via JAK2/STAT3 signaling pathway].

The present study was aimed to investigate the underlying mechanisms of the protective effect of proanthocyanidin (Pro) against hypoxia/reoxygenation (H/R) injury in H9C2 cells with a focus on Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway. H9C2 cells were randomly assigned to 5 groups, including the control group (Con), the H/R-injured group (H/R), the Pro-treated group (H/R+Pro), the JAK2 siRNA-treated group (H/R+Pro+JAK2 siRNA) and the JAK2 siRNA control group (H/R+JAK2 siRNA). The cells were pretreated with Pro (40 µmol/L) for 8 h before 2 h of hypoxia and 4 h of reoxygenation. Cellular viability and apoptosis rate were detected by MTT and TUNEL methods, and superoxide generation was measured. JAK2/STAT3 signaling, oxidative stress markers and endoplasmic reticulum stress markers were also detected by Western blot. We found that Pro treatment significantly improved cellular viability and reduced apoptosis rate in H/R-treated H9C2 cells. In addition, Pro treatment significantly up-regulated the phosphorylation levels of JAK2 and STAT3, down-regulated the superoxide generation, gp91phox, glucose-regulated protein 78 (GRP78), CCAAT/enhancer binding protein homologous protein (CHOP) and caspase-12 expression. However, these protective effects of Pro were all attenuated by JAK2 siRNA administration. Taken together, we demonstrated that Pro protects H9C2 cells against H/R-induced oxidative stress and endoplasmic reticulum stress injury via JAK2/STAT3 signaling pathway.

[EPCAM-positive normal hepatic progenitor cells transformation into liver stem cells and HBx-mediated effects on stability in adult mouse].

OBJECTIVE: To investigate the transformative potential of hepatic progenitor cells to differentiate into liver stem cells using a normal adult mouse system and to determine the effects of HBx protein in these liver stem cells' differentiation into hepatic cells. METHODS: Hepatic progenitor cells were obtained from mice by means of an optimized two-step digestion and perfusion method followed by joint differential centrifugation and density gradient centrifugation. Transformation of the hepatic progenitor cells into liver stem cells was observed by immunofluorescent detection of CD 133, EPCAM, CD49f and CK19. Differentiation of the resultant liver stem cells into hepatic cells and bile duct epithelial cells was observed after DMSO addition by Periodic Acid-Schiff (PAS) staining followed by cell immunofluorescence and flow cytometry. To determine the effects of HBx on these liver stem cells' ability to differentiate into hepatic cells, cell transfection was used followed by observation of morphology and proliferation capacity. RESULTS: Cell viability of the isolated hepatic progenitor cells was 78.67+/-4.04%. Stimulation with EGF and collagen led to growth of some of the paving-stone shaped cells attached to the hepatic progenitor cells which had gathered into spherical clumps, as is the nature of stem cells. The liver stem cells showed high expression of CD133, CD49f and CK19, and low expression of EPCAM. Under the effect of DMSO, the liver stem cells differentiated into hepatocytes and bile duct epithelial cells. After HBx transfecfion, the liver stem cells maintained the characteristic shape of stem cells and showed enhanced proliferation. CONCLUSION: EPCAM-positive adult hepatic progenitor cells can transform into liver stem cells.The HBx protein may play an important role in maintaining the stability of liver stem cells in the adult mouse.

Acute liver failure in Chinese children: a multicenter investigation.

BACKGROUND: Currently, no documentation is available regarding Chinese children with acute liver failure (ALF). This study was undertaken to investigate etiologies and outcomes of Chinese children with ALF. METHODS: We retrospectively enrolled 32 pediatric patients with ALF admitted in five hospitals in different areas of China from January 2007 to December 2012. The coagulation indices, serum creatinine, serum lactate dehydrogenase, blood ammonia and prothrombin activity were analyzed; the relationship between these indices and mortality was evaluated by multivariate analysis. RESULTS: The most common causes of Chinese children with ALF were indeterminate etiology (15/32), drug toxicity (8/32), and acute cytomegalovirus hepatitis (6/32). Only 1 patient (3.13%) received liver transplantation and the spontaneous mortality of Chinese children with ALF was 58.06% (18/31). Patients who eventually died had higher baseline levels of international normalized ratio (P=0.01), serum creatinine (P=0.04), serum lactate dehydrogenase (P=0.01), blood ammonia (P<0.01) and lower prothrombin activity (P=0.01) than those who survived. Multivariate analysis showed that the entry blood ammonia was the only independent factor significantly associated with mortality (odds ratio=1.069, 95% confidence interval 1.023-1.117, P<0.01) and it had a sensitivity of 94.74%, a specificity of 84.62% and an accuracy of 90.63% for predicting the death. Based on the established model, with an increase of blood ammonia level, the risk of mortality would increase by 6.9%. CONCLUSIONS: The indeterminate causes predominated in the etiologies of ALF in Chinese children. The spontaneous mortality of pediatric patients with ALF was high, whereas the proportion of patients undergoing liver transplantation was significantly low. Entry blood ammonia was a reliable predictor for the death of pediatric patients with ALF.

Chronic intermittent hypoxia impaired collagen synthesis in mouse genioglossus via ROS accumulation: A transcriptomic analysis.

Obstructive sleep apnea (OSA) is a sleep-related breathing disorder characterized by intermittent and recurrent upper airway collapse during sleep that leads to chronic intermittent hypoxia (CIH). The genioglossus (GG) is the largest dilator muscle, which controls the upper airway and plays an important role in OSA pathology. Elucidating its genetic alterations may help identify potential targets for OSA. However, the genetic aspects of the GG in CIH mice remain unclear. Here, we have conducted an RNA sequencing (RNA-Seq) analysis to assess the differentially expressed genes (DEGs) in the GG between CIH mice and normoxia (NOR) mice. A total of 637 DEGs were identified to be dysregulated in CIH mice compared with control mice. Bioinformatics analysis showed that the DEGs were related to various physiological processes, such as the endogenous stimulus responses, cellular component organization and metabolic processes. Extracellular matrix (ECM)-receptor interaction was the top KEGG pathway in the environmental information processing category with high significance and large fold changes. From the gene weight distributions of collagen (Col)-related biological processes (BPs), we found several significant DEGs, such as Col1a1, Col1a2, Mmp2, Col3a1, Col5a1, Fmod, and Col5a2. A PPI network showed that Col1a1 was linked to ECM-receptor interactions, responses to reactive oxygen species (ROS) and Col-related BPs. It was verified in vivo and in vitro that hypoxia can induce excess ROS and reduce Col expression levels. Moreover, we found NAC can effectively scavenge ROS and restore collagen synthesis. These findings contribute to a better understanding of the mechanisms linking OSA and upper airway muscle injury and may help identify potential therapeutic targets.

Research review on the pollution of antibiotic resistance genes in livestock and poultry farming environments.

Increasingly serious pollution of antibiotic resistance genes (ARGs) caused by the abuse of antibiotics in livestock and poultry industry has raised worldwide concerns. ARGs could spread among various farming environmental media through adsorption, desorption, migration, and also could transfer into human gut microbiome by hori-zontal gene transfer (HGT), posing potential threats to public health. However, the comprehensive review on the pollution patterns, environmental behaviors, and control techniques of ARGs in livestock and poultry environments in view of One Health is still inadequate, resulting in the difficulties in effectively assessing ARGs transmission risk and developing the efficient control strategies. Here, we analyzed the pollution characteristics of typical ARGs in various countries, regions, livestock species, and environmental media, reviewed the critical environmental fate and influencing factors, control strategies, and the shortcomings of current researches about ARGs in the livestock and poultry farming industry combined with One Health philosophy. In particular, we addressed the importance and urgency of identifying the distribution characteristics and environmental process mechanisms of ARGs, and developing green and efficient ARG control means in livestock farming environments. We further proposed gaps and prospects for the future research. It would provide theoretical basis for the research on health risk assessment and technology exploitation of alleviating ARG pollution in livestock farming environment.

Rational Design of Waterborne Polyurethane Pressure Sensitive Adhesives for Different Working Temperatures.

The appropriate pressure sensitive adhesion performances at working temperature are vital for the applications of waterborne polyurethane (WPU). Understanding the relationship among rheological behaviors, macromolecular structures and adhesive performances can be very useful to the rational design of waterborne polyurethane pressure sensitive adhesives (WPU-PSAs) for different operating temperatures, as well as other kinds of adhesives. In this study, four kinds of WPU-PSAs were prepared by reacting polypropylene glycol (PPG), hydrogenated hydroxyl-terminated polybutadiene (HHTPB), dimethyl alcohol propionic acid (DMPA), 1,6-hexamethylene diisocyanate (HDI) and four kinds of chain extenders. Gel permeation chromatography (GPC), swelling and rheology tests were used in parallel with an analysis of adhesive performances of the dried films of the adhesives. Results showed that, in addition to the nature of chain extenders playing a role on the rheological behaviors and adhesive performances of polymer, the gel content could be used to adjust the macromolecular structure and molecular weight distribution of polymer, thus distinctly affected the adhesive performances of PSA. The relationship among rheological behaviors, macromolecular structure and adhesive performances was investigated, and the rational design of WPU was achieved with appropriate pressure sensitive adhesion properties for different working temperatures of 25 and 60 °C.

Icariin attenuates excessive alcohol consumption-induced susceptibility to atrial fibrillation through SIRT3 signaling.

Excessive alcohol consumption has long been identified as a risk factor for adverse atrial remodeling and atrial fibrillation (AF). Icariin is a principal active component from traditional Chinese medicine Herba Epimedii and has been demonstrated to exert potential antiarrhythmic effect. The present study was designed to evaluate the effect of icariin against alcohol-induced atrial remodeling and disruption of mitochondrial dynamics and furthermore, to elucidate the underlying mechanisms. Excessive alcohol-treated C57BL/6 J mice were infected with serotype 9 adeno-associated virus (AAV9) carrying mouse SIRT3 gene or negative control virus. Meanwhile, icariin (50 mg/kg/d) was administered to the animals in the presence or absence of AAV9 carrying SIRT3 shRNA. We noted that 8 weeks of icariin treatment effectively attenuated alcohol consumption-induced atrial structural and electrical remodeling as evidenced by reduced AF inducibility and reversed atrial electrical conduction pattern as well as atrial enlargement. Furthermore, icariin-treated group exhibited significantly enhanced atrial SIRT3-AMPK signaling, decreased atrial mitoSOX fluorescence and mitochondrial fission markers, elevated mitochondrial fusion markers (MFN1, MFN2) as well as NRF-1-Tfam-mediated mitochondrial biogenesis. Importantly, these beneficial effects were mimicked by SIRT3 overexpression while abolished by SIRT3 knockdown. These data revealed that targeting atrial SIRT3-AMPK signaling and preserving mitochondrial dynamics might serve as the novel therapeutic strategy against alcohol-induced AF genesis. Additionally, icariin ameliorated atrial remodeling and mitochondrial dysfunction by activating SIRT3-AMPK signaling, highlighting the use of icariin as a promising antiarrhythmic agent in this circumstance.

Interferon-beta inhibits human glioma stem cell growth by modulating immune response and cell cycle related signaling pathways.

Malignant Glioma is characterized by strong self-renewal potential and immature differentiation potential. The main reason is that malignant glioma holds key cluster cells, glioma stem cells (GSCs). GSCs contribute to tumorigenesis, tumor progression, recurrence, and treatment resistance. Interferon-beta (IFN-ß) is well known for its anti-proliferative efficacy in diverse cancers. IFN-ß also displayed potent antitumor effects in malignant glioma. IFN-ß affect both GSCs and Neural stem cells (NSCs) in the treatment of gliomas. However, the functional comparison, similar or different effects of IFN-ß on GSCs and NSCs are rarely reported. Here, we studied the similarities and differences of the responses to IFN-ß between human GSCs and normal NSCs. We found that IFN-ß preferentially inhibited GSCs over NSCs. The cell body and nucleus size of GSCs increased after IFN-ß treatment, and the genomic analysis revealed the enrichment of the upregulated immune response, cell adhesion genes and down regulated cell cycle, ribosome pathways. Several typical cyclin genes, including cyclin A2 (CCNA2), cyclin B1 (CCNB1), cyclin B2 (CCNB2), and cyclin D1 (CCND1), were significantly downregulated in GSCs after IFN-ß stimulation. We also found that continuous IFN-ß stimulation after passage further enhanced the inhibitory effect. Our study revealed how genetic diversity resulted in differential effects in response to IFN-ß treatment. These results may contribute to improve the applications of IFN-ß in anti-cancer immunotherapy. In addition, these results may also help to design more effective pharmacological strategies to target cancer stem cells while protecting normal neural stem cells.

Activation of PKG-CREB-KLF15 by melatonin attenuates Angiotensin II-induced vulnerability to atrial fibrillation via enhancing branched-chain amino acids catabolism.

Mitochondrial reactive oxygen species (ROS) damage and atrial remodeling serve as the crucial substrates for the genesis of atrial fibrillation (AF). Branched-chain amino acids (BCAAs) catabolic defect plays critical roles in multiple cardiovascular diseases. However, the alteration of atrial BCAA catabolism and its role in AF remain largely unknown. This study aimed to explore the role of BCAA catabolism in the pathogenesis of AF and to further evaluate the therapeutic effect of melatonin with a focus on protein kinase G (PKG)-cAMP response element binding protein (CREB)-Krüppel-like factor 15 (KLF15) signaling. We found that angiotensin II-treated atria exhibited significantly elevated BCAA level, reduced BCAA catabolic enzyme activity, increased AF vulnerability, aggravated atrial electrical and structural remodeling, and enhanced mitochondrial ROS damage. These deleterious effects were attenuated by melatonin co-administration while exacerbated by BCAA oral supplementation. Melatonin treatment ameliorated BCAA-induced atrial damage and reversed BCAA-induced down-regulation of atrial PKGIα expression, CREB phosphorylation as well as KLF15 expression. However, inhibition of PKG partly abolished melatonin-induced beneficial actions. In summary, these data demonstrated that atrial BCAA catabolic defect contributed to the pathogenesis of AF by aggravating tissue fibrosis and mitochondrial ROS damage. Melatonin treatment ameliorated Ang II-induced atrial structural as well as electrical remodeling by activating PKG-CREB-KLF15. The present study reveals additional mechanisms contributing to AF genesis and highlights the opportunity of a novel therapy for AF by targeting BCAA catabolism. Melatonin may serve as a potential therapeutic agent for AF intervention.

Glioma stem cells and neural stem cells respond differently to BMP4 signaling.

Malignant glioma is a highly heterogeneous and invasive primary brain tumor characterized by high recurrence rates, resistance to combined therapy, and dismal prognosis. Glioma stem cells (GSCs) are likely responsible for tumor progression, resistance to therapy, recurrence, and poor prognosis owing to their high self-renewal and tumorigenic potential. As a family member of BMP signaling, bone morphogenetic protein4 (BMP4) has been reported to induce the differentiation of GSCs and neural stem cells (NSCs). However, the molecular mechanisms underlying the BMP4-mediated effects in these two cell types are unclear. In this study, we treated hGSCs and hNSCs with BMP4 and compared the phenotypic and transcriptional changes between these two cell types. Phenotypically, we found that the growth of hGSCs was greatly inhibited by BMP4, but the same treatment only increased the cell size of hNSCs. While the RNA sequencing results showed that BMP4 treatment evoked significantly transcriptional changes in both hGSCs and hNSCs, the profiles of differentially expressed genes were distinct between the two groups. A gene set that specifically targeted the proliferation and differentiation of hGSCs but not hNSCs was enriched and then validated in hGSC culture. Our results suggested that hGSCs and hNSCs responded differently to BMP4 stimulation. Understanding and investigating different responses between hGSCs and hNSCs will benefit finding partner factors working together with BMP4 to further suppress GSCs proliferation and stemness without disturbing NSCs.

Polydatin attenuates chronic alcohol consumption-induced cardiomyopathy through a SIRT6-dependent mechanism.

Polydatin has attracted much attention as a potential cardioprotective agent against ischemic heart disease and diabetic cardiomyopathy. However, the effect and mechanism of polydatin supplementation on alcoholic cardiomyopathy (ACM) are still unknown. This study aimed to determine the therapeutic effect of polydatin against ACM and to explore the molecular mechanisms with a focus on SIRT6-AMP-activated protein kinase (AMPK) signaling and mitochondrial function. The ACM model was established by feeding C57/BL6 mice with an ethanol Lieber-DeCarli diet for 12 weeks. The mice received polydatin (20 mg kg-1) or vehicle treatment. We showed that polydatin treatment not only improved cardiac function but also reduced myocardial fibrosis and dynamin-related protein 1 (Drp-1)-mediated mitochondrial fission, and enhanced PTEN-induced putative kinase 1 (PINK1)-Parkin-dependent mitophagy in alcohol-treated myocardium. Importantly, these beneficial effects were mimicked by SIRT6 overexpression but abolished by the infection of recombinant serotype 9 adeno-associated virus (AAV9) carrying SIRT6-specific small hairpin RNA. Mechanistically, alcohol consumption induced a gradual decrease in the myocardial SIRT6 level, while polydatin effectively activated SIRT6-AMPK signaling and modulated mitochondrial dynamics and mitophagy, thus reducing oxidative stress damage and preserving mitochondrial function. In summary, these data present new information regarding the therapeutic actions of polydatin, suggesting that the activation of SIRT6 signaling may represent a new approach for tackling ACM-related cardiac dysfunction.

[Orofacial myofunctional therapy improves facial morphology of children with obstructive sleep apnea after adenotonsillectomy].

PURPOSE: This study investigated the effectiveness of orofacial myofunctional therapy(OMT) in improving facial morphology of children with obstructive sleep apnea (OSA) after adenotonsillectomy (AT). METHODS: Ten children aged from 4-7 years with persistent oral breathing for more than 1 month after adenotonsillectomy were chosen to receive orofacial myofunctional therapy. The patients were required to take photos before and after orofacial myofunctional therapy. In order to compare the soft changes before and after OMT treatment, twelve representative mark points were selected and used for proportion and angle measurements. Graphpad Prism 8 statistical software was used for statistical analysis, to compare the differences in facial morphology of patients before and after treatment. RESULTS: Compared with before OMT, a significant difference was found in the proportion of Sn-Ls/Sn-Stms(P=0.0002), Sn-Stms/Sn-Me'(P<0.05), as well as in the angle of Gs-Sn-Pos (P<0.05), nasolabial angle(P=0.0005), mentolabial angle (P=0.0026) after OMT treatment. CONCLUSIONS: Orofacial myofunctional therapy can be considered as an effective complementary treatment for OSA patients with oral breathing after adenotonsillectomy.

HIF-1α activator DMOG inhibits alveolar bone resorption in murine periodontitis by regulating macrophage polarization.

Periodontitis is initiated by serious and sustained bacterial infection and ultimately results in chronic immune-mediated inflammation, tissue destruction, and bone loss. The pathogenesis of periodontitis remains unclear. Host immunological responses to periodontal bacteria ultimately determine the severity and mechanisms governing periodontitis progression. This study aimed to clarify the effect of the hypoxia-inducible factor-1α (HIF-1α) activator dimethyloxalylglycine (DMOG) on a mouse periodontitis model and its underlying role in macrophage polarization. qRT-PCR analysis showed that DMOG inhibited the M1-like polarization of both RAW264.7 macrophages and murine bone marrow macrophages (BMMs) and downregulated TNF-α, IL-6, CD86, and MCP-1 expression in vitro. Immunofluorescence staining and flow cytometry also confirmed the less percentage of F4/80 + CD86 + cells after DMOG treatment. The phosphorylation of NF-κB pathway was also inhibited by DMOG with higher level of HIF-1α expression. Furthermore, mice treated with DMOG showed decreased alveolar bone resorption in the experimental periodontitis model, with significant increases in alveolar bone volume/tissue volume (BV/TV) and bone mineral density (BMD). DMOG treatment of mice decreased the ratio of M1/M2 (CD86+/CD206+) macrophages in periodontal tissues, resulting in the downregulation of proinflammatory cytokines such as TNF-α and IL-6 and increased levels of anti-inflammatory factors such as IL-4 and IL-10. DMOG treatment promoted the number of HIF-1α-positive cells in periodontal tissues. This study demonstrated the cell-specific roles of DMOG in macrophage polarization in vitro and provided insight into the mechanism underlying the protective effect of DMOG in a model of periodontitis.

A Fast and Efficient Approach to Obtaining High-Purity Glioma Stem Cell Culture.

Glioma is the most common and malignant primary brain tumor. Patients with malignant glioma usually have a poor prognosis due to drug resistance and disease relapse. Cancer stem cells contribute to glioma initiation, progression, resistance, and relapse. Hence, quick identification and efficient understanding of glioma stem cells (GSCs) are of profound importance for therapeutic strategies and outcomes. Ideally, therapeutic approaches will only kill cancer stem cells without harming normal neural stem cells (NSCs) that can inhibit GSCs and are often beneficial. It is key to identify the differences between cancer stem cells and normal NSCs. However, reports detailing an efficient and uniform protocol are scarce, as are comparisons between normal neural and cancer stem cells. Here, we compared different protocols and developed a fast and efficient approach to obtaining high-purity glioma stem cell by tracking observation and optimizing culture conditions. We examined the proliferative and differentiative properties confirming the identities of the GSCs with relevant markers such as Ki67, SRY-box containing gene 2, an intermediate filament protein member nestin, glial fibrillary acidic protein, and s100 calcium-binding protein (s100-beta). Finally, we identified distinct expression differences between GSCs and normal NSCs including cyclin-dependent kinase 4 and tumor protein p53. This study comprehensively describes the features of GSCs, their properties, and regulatory genes with expression differences between them and normal stem cells. Effective approaches to quickly obtaining high-quality GSCs from patients should have the potential to not only help understand the diseases and the resistances but also enable target drug screening and personalized medicine for brain tumor treatment.