The role of STAT3/VAV3 in glucolipid metabolism during the development of HFD-induced MAFLD.

Metabolic-associated fatty liver disease (MAFLD) is a globally prevalent chronic hepatic disease. Previous studies have indicated that the activation of the signal transducer and activator of transcription3 (STAT3) plays a vital role in MAFLD progression at the very beginning. However, the specific association between STAT3 and abnormal hepatic metabolism remains unclear. In this study, activated inflammation was observed to induce abnormal glucolipid metabolic disorders in the hepatic tissues of high-fat diet (HFD)-fed ApoE-/- mice. Furthermore, we found that the activation of STAT3 induced by HFD might function as a transcriptional factor to suppress the expression of VAV3, which might participate in intracellular glucolipid metabolism and the regulation of glucose transporter 4 (GLUT4) storage vesicle traffic in the development of MAFLD both in vitro and in vivo. We verified that VAV3 deficiency could retard the GLUT4 membrane translocation and impair the glucose homeostasis. Additionally, VAV3 participates in cholesterol metabolism in hepatocytes, eventually resulting in the accumulation of intracellular cholesterol. Moreover, rAAV8-TBG-VAV3 was conducted to restore the expression of VAV3 in HFD-fed ApoE-/- mice. VAV3 overexpression was observed to improve glucose homeostasis as well as attenuate hepatic cholesterol accumulation in vivo. In conclusion, the STAT3/VAV3 signaling pathway might play a significant role in MAFLD by regulating glucose and cholesterol metabolism, and VAV3 might be a potential therapeutic strategy which could consequently ameliorate MAFLD.

Network pharmacology and molecular docking analysis on Shenfu Qiangxin indicate mTOR is a potential target to treat heart failure.

BACKGROUND: Heart failure (HF) is one of the major causes of mortality worldwide with high recurrence rate and poor prognosis. Our study aimed to investigate potential mechanisms and drug targets of Shenfu Qiangxin (SFQX), a cardiotonic-diuretic traditional Chinese medicine, in treating HF. METHODS: An HF-related and SFQX-targeted gene set was established using disease-gene databases and the Traditional Chinese Medicine Systems Pharmacology database. We performed gene function and pathway enrichment analysis and constructed protein-protein interaction (PPI) network to investigate the potential mechanisms. We also performed molecular docking to analyze the interaction patterns between the active compounds and targeted protein. RESULTS: A gene set with 217 genes was identified. The gene function enrichment indicated that SFQX can regulate apoptotic process, inflammatory response, response to oxidative stress and cellular response to hypoxia. The pathway enrichment indicated that most genes were involved in PI3K-Akt pathway. Eighteen hub target genes were identified in PPI network and subnetworks. mTOR was the key gene among hub genes, which are involved in PI3K-Akt pathway. The molecular docking analysis indicated that 6 active compounds of SFQX can bind to the kinase domain of mTOR, which exerted potential therapeutic mechanisms of SFQX in treating HF. CONCLUSIONS: The results of network pharmacology analysis highlight the intervention on PI3K-Akt pathway of SFQX in the treatment of HF. mTOR is a key drug target to help protect myocardium.

Effective substances and molecular mechanisms guided by network pharmacology: An example study of Scrophulariae Radix treatment of hyperthyroidism and thyroid hormone-induced liver and kidney injuries.

ETHNOPHARMACOLOGICAL RELEVANCE: Scrophulariae Radix (Xuanshen [XS]) has been used for several years to treat hyperthyroidism. However, its effective substances and pharmacological mechanisms in the treatment of hyperthyroidism and thyroid hormone-induced liver and kidney injuries have not yet been elucidated. AIM OF THE STUDY: This study aimed to explore the pharmacological material basis and potential mechanism of XS therapy for hyperthyroidism and thyroid hormone-induced liver and kidney injuries based on network pharmacology prediction and experimental validation. MATERIALS AND METHODS: Based on 31 in vivo XS compounds identified using ultra-performance liquid chromatography tandem quadruple exactive orbitrap high-resolution accurate-mass spectrometry (UPLC-QE-HRMS), a network pharmacology approach was used for mechanism prediction. Systematic networks were constructed to identify the potential molecular targets, biological processes (BP), and signaling pathways. A component-target-pathway network was established. Mice were administered levothyroxine sodium through gavage for 30 d and then treated with different doses of XS extract with or without propylthiouracil (PTU) for 30 d. Blood, liver, and kidney samples were analyzed using an enzyme-linked immunosorbent assay (ELISA) and western blotting. RESULTS: A total of 31 prototypes, 60 Phase I metabolites, and 23 Phase II metabolites were tentatively identified in the plasma of rats following the oral administration of XS extract. Ninety-six potential common targets between the 31 in vivo compounds and the diseases were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that Bcl-2, BAD, JNK, p38, and ERK1/2 were the top targets. XS extract with or without PTU had the following effects: inhibition of T3/T4/fT3/fT4 caused by levothyroxine; increase of TSH levels in serum; restoration of thyroid structure; improvement of liver and kidney structure and function by elevating the activities of anti-oxidant enzymes catalase (CAT),superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px); activation anti-apoptotic proteins Bcl-2; inhibition the apoptotic protein p-BAD; downregulation inflammation-related proteins p-ERK1/2, p-JNK, and p-p38; and inhibition of the aggregation of pro-inflammatory cytokines TNF-α, IL-1ß, and IL-6, as well as immune cells in the liver. CONCLUSION: XS can be used to treat hyperthyroidism and liver and kidney injuries caused by thyroid hormones through its anti-oxidant, anti-inflammatory, and anti-apoptotic properties. In addition, serum pharmacochemical analysis revealed that five active compounds, namely 4-methylcatechol, sugiol, eugenol, acetovanillone, and oleic acid, have diverse metabolic pathways in vivo and exhibit potential as effective therapeutic agents.

Unraveling the Intricate Network of lncRNAs in Corneal Epithelial Wound Healing: Insights Into the Regulatory Role of linc17500.

Purpose: Epigenetic mechanisms orchestrate a harmonious process of corneal epithelial wound healing (CEWH). However, the precise role of long non-coding RNAs (lncRNAs) as key epigenetic regulators in mediating CEWH remains elusive. Here, we aimed to elucidate the functional contribution of lncRNAs in regulating CEWH. Methods: We used a microarray to characterize lncRNA expression profiling during mouse CEWH. Subsequently, the aberrant lncRNAs and their cis-associated genes were subjected to comprehensive Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blot analyses were performed to determine the expression profiles of key markers during CEWH. The in vivo effects of linc17500 on this process were investigated through targeted small interfering RNA (siRNA) injection. Post-siRNA treatment, corneal re-epithelialization was assessed, alongside the expression of cytokeratins 12 and 14 (Krt12 and Krt14) and Ki67. Effects of linc17500 on mouse corneal epithelial cell (TKE2) proliferation, cell cycle, and migration were assessed by multicellular tumor spheroids (MTS), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, and scratch-wound assay, respectively. Results: Microarray analysis revealed dysregulation of numerous lncRNA candidates during CEWH. Bioinformatic analysis provided valuable annotations regarding the cis-associated genes of these lncRNAs. In vivo experiments demonstrated that knockdown of linc17500 resulted in delayed CEWH. Furthermore, the knockdown of linc17500 and its cis-associated gene, CDC28 protein kinase regulatory subunit 2 (Cks2), was found to impede TKE2 cell proliferation and migration. Notably, downregulation of linc17500 in TKE2 cells led to suppression of the activation status of Akt and Rb. Conclusions: This study sheds light on the significant involvement of lncRNAs in mediating CEWH and highlights the regulatory role of linc17500 on TKE2 cell behavior. Translational Relevance: These findings provide valuable insights for future therapeutic research aimed at addressing corneal wound complications.

Involvement of plasminogen activator inhibitor-1 in p300/p53-mediated age-related atrial fibrosis.

Plasminogen activator inhibitor-1 (PAI-1), a key regulator of the fibrinolytic system, is also intimately involved in the fibrosis. Although PAI-1 may be involved in the occurrence of atrial fibrillation (AF) and thrombosis in the elderly, but whether it participated in aging-related atrial fibrosis and the detailed mechanism is still unclear. We compared the transcriptomics data of young (passage 4) versus senescent (passage 14) human atrial fibroblasts and found that PAI-1 was closely related to aging-related fibrosis. Aged mice and senescent human and mouse atrial fibroblasts underwent electrophysiological and biochemical studies. We found that p300, p53, and PAI-1 protein expressions were increased in the atrial tissue of aged mice and senescent human and mouse atrial fibroblasts. Curcumin or C646 (p300 inhibitor), or p300 knockdown inhibited the expression of PAI-1 contributing to reduced atrial fibroblasts senescence, atrial fibrosis, and the AF inducibility. Furthermore, p53 knockdown decreased the protein expression of PAI-1 and p21 in senescent human and mouse atrial fibroblasts. Our results suggest that p300/p53/PAI-1 signaling pathway participates in the mechanism of atrial fibrosis induced by aging, which provides new sights into the treatment of elderly AF.

IL-6/gp130/STAT3 signaling contributed to the activation of the PERK arm of the unfolded protein response in response to chronic ß-adrenergic stimulation.

Prolonged activation of the PERK branch of the unfolded protein response (UPR) promotes cardiomyocytes apoptosis in response to chronic ß-adrenergic stimulation. STAT3 plays a critical role in ß-adrenergic functions in the heart. However, whether STAT3 contributed to ß-adrenoceptor-mediated PERK activation and how ß-adrenergic signaling activates STAT3 remains unclear. This study aimed to investigate whether STAT3-Y705 phosphorylation contributed to the PERK arm activation in cardiomyocytes and if IL-6/gp130 signaling was involved in the chronic ß-AR-stimulation-induced STAT3 and PERK arm activation. We found that the PERK phosphorylation was positively associated with STAT3 activation. Wild-type STAT3 plasmids transfection activated the PERK/eIF2α/ATF4/CHOP pathway in cardiomyocytes while dominant negative Y705F STAT3 plasmids caused no obvious effect on PERK signaling. Stimulation with isoproterenol produced a significant increase in the level of IL-6 in the cardiomyocyte's supernatants, while IL-6 silence inhibited PERK phosphorylation but failed to attenuate STAT3 activation in response to isoproterenol stimulation. Gp130 silence attenuated isoproterenol-induced STAT3 activation and PERK phosphorylation. Inhibiting IL-6/gp130 pathway by bazedoxifene and inhibiting STAT3 by stattic both reversed isoproterenol-induced STAT3-Y705 phosphorylation, ROS production, PERK activation, IRE1α activation, and cardiomyocytes apoptosis in vitro. Bazedoxifene (5 mg/kg/day by oral gavage once a day) exhibited similar effect as carvedilol (10 mg/kg/day by oral gavage once a day) on attenuating chronic isoproterenol (30 mg/kg by abdominal injection once a day, 7 days) induced cardiac systolic dysfunction, cardiac hypertrophy and fibrosis in C57BL/6 mice. Meanwhile, bazedoxifene attenuates isoproterenol-induced STAT3-Y705 phosphorylation, PERK/eIF2α/ATF4/CHOP activation, IRE1α activation, and cardiomyocytes apoptosis to a similar extend as carvedilol in the cardiac tissue of mice. Our results showed that chronic ß-adrenoceptor-mediated stimulation activated the STAT3 and PERK arm of the UPR at least partially via IL-6/gp130 pathway. Bazedoxifene has great potential to be used as an alternative to conventional ß-blockers to attenuate ß-adrenoceptor-mediated maladaptive UPR.

Sacubitril/valsartan reduces susceptibility to atrial fibrillation by improving atrial remodeling in spontaneously hypertensive rats.

AIM: Sacubitril/valsartan (Sac/Val, LCZ696), the world's first angiotensin receptor-neprilysin inhibitor (ARNi), has been widely used in the treatment of heart failure. However, the use of Sac/Val in the treatment of atrial fibrillation (AF), especially AF with hypertension, has been less reported. We investigated the effect of Sac/Val on atrial remodeling and hypertension-related AF. METHODS: The AF induction rate and electrophysiological characteristics of spontaneously hypertensive rats (SHRs) treated with Sac/Val or Val were detected by rapid atrial pacing and electrical mapping/optical mapping. The whole-cell patch-clamp and Western blot were used to observe electrical/structural remodeling of atrial myocytes/tissue of rats and atrium-derived HL-1 cells cultured under 40 mmHg in vitro. RESULTS: Sac/Val was superior to Val in reducing blood pressure, myocardial hypertrophy and susceptibility of AF in SHRs. The shorten action potentials duration (APD), decreased L type calcium channel current (ICa,L) and Cav1.2, increased ultrarapid delayed rectified potassium current (Ikur) and Kv1.5 in atrial myocytes/tissue of SHRs could be better improved by Sac/Val, as well as the levels of atrial fibrosis. While the protein expression of angiotensin-converting enzyme-1 (ACE-1), angiotensin, angiotensin II type I AT1 receptor (AT1R) and neprilysin (NEP) were increased, which could be more effective ameliorated by Sac/Val than Val. Furthermore, Val + Sacubitrilat (LBQ657) (an active NEP inhibitor) was also superior to LBQ657 or Val in improving the electrical and structural remodeling of HL-1 cells through inhibiting NEP. CONCLUSION: Sac/Val can improve atrial structural and electrical remodeling induced by hypertension and reduce the AF susceptibility by inhibiting RAS and NEP. The above effects of Sac/Val were superior to Val alone.

Notopterol Ameliorates Hyperuricemia-Induced Cardiac Dysfunction in Mice.

Notopterol is a naturally occurring furanocoumarin compound found in the root of Notopterygium incisum. Hyperuricemia involves the activation of chronic inflammation and leads to cardiac damage. Whether notopterol has cardioprotective potential in hyperuricemia mice remains elusive. The hyperuricemic mouse model was constructed by administration of potassium oxonate and adenine every other day for six weeks. Notopterol (20 mg/kg) and allopurinol (10 mg/kg) were given daily as treatment, respectively. The results showed that hyperuricemia dampened heart function and reduced exercise capacity. Notopterol treatment improved exercise capacity and alleviated cardiac dysfunction in hyperuricemic mice. P2X7R and pyroptosis signals were activated both in hyperuricemic mice and in uric acid-stimulated H9c2 cells. Additionally, it was verified that inhibition of P2X7R alleviated pyroptosis and inflammatory signals in uric acid-treated H9c2 cells. Notopterol administration significantly suppressed expression levels of pyroptosis associated proteins and P2X7R in vivo and in vitro. P2X7R overexpression abolished the inhibition effect of notopterol on pyroptosis. Collectively, our findings suggested that P2X7R played a critical role in uric acid-induced NLRP3 inflammatory signals. Notopterol inhibited pyroptosis via inhibiting the P2X7R/NLRP3 signaling pathway under uric acid stimulation. Notopterol might represent a potential therapeutic strategy against pyroptosis and improve cardiac function in hyperuricemic mice.

STAT3 signaling promotes cardiac injury by upregulating NCOA4-mediated ferritinophagy and ferroptosis in high-fat-diet fed mice.

High-fat diet (HFD) intake provokes obesity and cardiac anomalies. Recent studies have found that ferroptosis plays a role in HFD-induced cardiac injury, but the underlying mechanism is largely unclear. Ferritinophagy is an important part of ferroptosis that is regulated by nuclear receptor coactivator 4 (NCOA4). However, the relationship between ferritinophagy and HFD-induced cardiac damage has not been explored. In this study, we found that oleic acid/palmitic acid (OA/PA) increased the level of ferroptotic events including iron and ROS accumulation, upregulation of PTGS2 mRNA and protein levels, reduced SOD and GSH levels, and significant mitochondrial damage in H9C2 cells, which could be reversed by the ferroptosis inhibitor ferrostatin-1 (Fer-1). Intriguingly, we found that the autophagy inhibitor 3-methyladenine mitigated OA/PA-induced ferritin downregulation, iron overload and ferroptosis. OA/PA increased the protein level of NCOA4. Knockdown of NCOA4 by SiRNA partly reversed the reduction in ferritin, mitigated iron overload and lipid peroxidation, and subsequently alleviated OA/PA-induced cell death, indicating that NCOA4-mediated ferritinophagy was required for OA/PA-induced ferroptosis. Furthermore, we demonstrated that NCOA4 was regulated by IL-6/STAT3 signaling. Inhibition or knockdown of STAT3 effectively reduced NCOA4 levels to protect H9C2 cells from ferritinophagy-mediated ferroptosis, whereas STAT3 overexpression by plasmid appeared to increase NCOA4 expression and contribute to classical ferroptotic events. Consistently, phosphorylated STAT3 upregulation, ferritinophagy activation, and ferroptosis induction also occurred in HFD-fed mice and were responsible for HFD-induced cardiac injury. In addition, we found evidence that piperlongumine, a natural compound, effectively reduced phosphorylated STAT3 levels to protect cardiomyocytes from ferritinophagy-mediated ferroptosis both in vitro and in vivo. Based on these findings, we concluded that ferritinophagy-mediated ferroptosis was one of the critical mechanisms contributing to HFD-induced cardiac injury. The STAT3/NCOA4/FTH1 axis might be a novel therapeutic target for the treatment of HFD-induced cardiac injury.

Efficiency and safety of high-power ablation guided by Lesion size index: An ex vivo porcine heart study.

BACKGROUND: Although Lesion size index (LSI) has been reported to highly predict radiofrequency lesion size in vitro, its accuracy in lesion size and steam pop estimation has not been well investigated for every possible scenario. METHODS: Initially, radiofrequency ablations were performed on porcine myocardial slabs at various power, CF, and time settings with blinded LSI. Subsequently, radiofrequency power at 20, 30, 40, 50, and 60 W was applied at CF values of 5, 10, 20, and 30 g to reach target LSIs of 4, 5, 6, and 7. Lesion size and steam pops were recorded for each ablation. RESULTS: Lesion size was positively correlated with LSI regardless of power settings (p < 0.001). The linear correlation coefficients of lesion size and LSI decreased at higher power settings. At high power combined with high CF settings (50 W/20 g), lesion depth and LSI showed an irrelevant correlation (p = 0.7855). High-power ablation shortened ablation time and increased the effect of resistive heating. LSI could predict the risk of steam pops at high-power settings with the optimal threshold of 5.65 (sensitivity, 94.1%; specificity, 46.1%). The ablation depth of the heavy heart was shallower than that of the light heart under similar ablation settings. CONCLUSIONS: LSI could predict radiofrequency lesion size and steam pops at high power settings in vitro, while synchronous high power and high CF should be avoided. Lighter hearts require relatively lower ablation settings to create appropriate ablation depth.

ATF3/SPI1/SLC31A1 Signaling Promotes Cuproptosis Induced by Advanced Glycosylation End Products in Diabetic Myocardial Injury.

Cuproptosis resulting from copper (Cu) overload has not yet been investigated in diabetic cardiomyopathy (DCM). Advanced glycosylation end products (AGEs) induced by persistent hyperglycemia play an essential role in cardiotoxicity. To clarify whether cuproptosis was involved in AGEs-induced cardiotoxicity, we analyzed the toxicity of AGEs and copper in AC16 cardiomyocytes and in STZ-induced or db/db-diabetic mouse models. The results showed that copper ionophore elesclomol induced cuproptosis in cardiomyocytes. It was only rescued by copper chelator tetrathiomolybdate rather than by other cell death inhibitors. Intriguingly, AGEs triggered cardiomyocyte death and aggravated it when incubated with CuCl2 or elesclomol-CuCl2. Moreover, AGEs increased intracellular copper accumulation and exhibited features of cuproptosis, including loss of Fe-S cluster proteins (FDX1, LIAS, NDUFS8 and ACO2) and decreased lipoylation of DLAT and DLST. These effects were accompanied by decreased mitochondrial oxidative respiration, including downregulated mitochondrial respiratory chain complex, decreased ATP production and suppressed mitochondrial complex I and III activity. Additionally, AGEs promoted the upregulation of copper importer SLC31A1. We predicted that ATF3 and/or SPI1 might be transcriptional factors of SLC31A1 by online databases and validated that by ATF3/SPI1 overexpression. In diabetic mice, copper and AGEs increases in the blood and heart were observed and accompanied by cardiac dysfunction. The protein and mRNA profile changes in diabetic hearts were consistent with cuproptosis. Our findings showed, for the first time, that excessive AGEs and copper in diabetes upregulated ATF3/SPI1/SLC31A1 signaling, thereby disturbing copper homeostasis and promoting cuproptosis. Collectively, the novel mechanism might be an alternative potential therapeutic target for DCM.

Acetyltransferase p300 regulates atrial fibroblast senescence and age-related atrial fibrosis through p53/Smad3 axis.

Atrial fibrosis induced by aging is one of the main causes of atrial fibrillation (AF), but the potential molecular mechanism is not clear. Acetyltransferase p300 participates in the cellular senescence and fibrosis, which might be involved in the age-related atrial fibrosis. Four microarray datasets generated from atrial tissue of AF patients and sinus rhythm (SR) controls were analyzed to find the possible relationship of p300 (EP300) with senescence and fibrosis. And then, biochemical assays and in vivo electrophysiological examination were performed on older AF patients, aging mice, and senescent atrial fibroblasts. The results showed that (1) the left atrial tissues of older AF patients, aging mouse, and senescence human atrial fibroblasts had more severe atrial fibrosis and higher protein expression levels of p300, p53/acetylated p53 (ac-p53)/p21, Smad3/p-Smads, and fibrosis-related factors. (2) p300 inhibitor curcumin and p300 knockdown treated aging mouse and senescence human atrial fibroblasts reduced the senescence ratio of atrial fibroblasts, ameliorated the atrial fibrosis, and decreased the AF inducibility. In contrast, over-expression of p300 can lead to the senescence of atrial fibroblasts and atrial fibrosis. (3) p53 knockdown decreased the expression of aging and fibrosis-related proteins. (4) Co-immunoprecipitation and immunofluorescence showed that p53 forms a complex with smad3 and directly regulates the expression of smad3 in atrial fibroblasts. Our findings suggest that the mechanism of atrial fibrosis induced by aging is, at least, partially dependent on the regulation of p300, which provides new sights into the AF treatment, especially for the elderly.

Anti-angiogenic properties of microRNA-29a in preclinical ocular models.

Abnormal neovascularization is an important cause of blindness in many ocular diseases, for which the etiology and pathogenic mechanisms remain incompletely understood. Recent studies have revealed the diverse roles of noncoding RNAs in various biological processes and facilitated the research and development of the clinical application of numerous RNA drugs, including microRNAs. Here, we report the antiangiogenic activity of microRNA-29a (miR-29a) in three animal models of ocular neovascularization. The miR-29a knockout (KO) mice displayed enhanced vessel pruning, resulting in a decreased vascularized area during retinal development. In contrast, miR-29a deletion in adult mice accelerated angiogenesis in preclinical disease models, including corneal neovascularization, oxygen-induced retinopathy, and choroidal neovascularization, while the administration of agomir-29a ameliorated pathological neovascularization. Furthermore, miR-29a exerted inhibitory effects on endothelial cell proliferation, migration, and tube formation capacities. RNA sequencing analysis of retinas from miR-29a KO mice and RNA interference experiments identified platelet-derived growth factor C and several extracellular matrix genes as downstream targets of miR-29a involved in regulating ocular angiogenesis. Our data suggest that miR-29a may be a promising clinical candidate for the treatment of neovascular diseases.

Cirsiliol regulates mitophagy in colon cancer cells via STAT3 signaling.

BACKGROUND: Mitophagy is a type of selective autophagy for dysfunctional mitochondria and plays a key role in tumorigenesis and cancer progression. However, whether mitophagy plays a role in colon cancer remains unclear. Cirsiliol is a natural product and has been found to exert anti-cancer effects in multiple tumors. The effects of cirsiliol in the tumorigenesis and progression of colon cancer remain unknown. METHODS: CCK8 assay, plate cloning assay, and cell scratch assay were performed to determine cell viability, colony formation, and wound healing abilities of HCT116 and SW480 cells. JC-1 staining, H2DCFDA staining, and Mito-Tracker Red staining were carried out to evaluate mitochondrial membrane potential (Δψm), intracellular reactive oxygen species (ROS) level, and mitochondrial morphology. Molecular docking technology was utilized to predict interaction of cirsiliol and signal transducer and activator of transcription 3 (STAT3). Immunofluorescence staining was used to measure nuclear translocation of STAT3. The protein levels of phosphorylated STAT3 (Y705), total STAT3, and mitophagy proteins were detected by western blot. RESULTS: In this study, we first found that cirsiliol inhibited cell viability, colony formation, and wound healing abilities of HCT116 and SW480 colon cancer cells. Moreover, cirsiliol suppressed Δψm, increased ROS production, and disrupted mitochondrial morphology via inhibiting the levels of mitophagy proteins including PINK1, Parkin, BNIP3, and FUNDC1. Application of mitophagy activator improved the levels of mitophagy-related proteins, and ameliorated Δψm and ROS levels. According to the result of molecular docking, we found that cirsiliol potentially bound to the SH2 domain of STAT3, the key domain for the functional activation of STAT3. Moreover, it was found that cirsiliol inhibited constitutive and IL­6­induced STAT3 phosphorylation and nuclear translocation by western blot and immunofluorescence analysis. Comparing with cirsiliol group, we found that overexpression of STAT3 restored the expressions of mitophagy proteins. CONCLUSIONS: Cirsiliol targets STAT3 to inhibit colon cancer cell proliferation by regulating mitophagy.

Myocardial protection of S-nitroso-L-cysteine in diabetic cardiomyopathy mice.

Diabetic cardiomyopathy (DCM) is a severe complication of diabetes mellitus that is characterized by aberrant myocardial structure and function and is the primary cause of heart failure and death in diabetic patients. Endothelial dysfunction plays an essential role in diabetes and is associated with an increased risk of cardiovascular events, but its role in DCM is unclear. Previously, we showed that S-nitroso-L-cysteine(CSNO), an endogenous S-nitrosothiol derived from eNOS, inhibited the activity of protein tyrosine phosphatase 1B (PTP1B), a critical negative modulator of insulin signaling. In this study, we reported that CSNO treatment induced cellular insulin-dependent and insulin-independent glucose uptake. In addition, CSNO activated insulin signaling pathway and promoted GLUT4 membrane translocation. CSNO protected cardiomyocytes against high glucose-induced injury by ameliorating excessive autophagy activation, mitochondrial impairment and oxidative stress. Furthermore, nebulized CSNO improved cardiac function and myocardial fibrosis in diabetic mice. These results suggested a potential site for endothelial modulation of insulin sensitivity and energy metabolism in the development of DCM. Data from these studies will not only help us understand the mechanisms of DCM, but also provide new therapeutic options for treatment.

Preexisting Cardiovascular Risk Factors and Coronary Artery Atherosclerosis in Patients with and without Cancer.

Cancer survivors suffer a higher risk of coronary artery atherosclerosis (CAA). Whether cancer patients had increased baseline CAA burden prior to cardiotoxic therapy remains unclear. We conducted a case-control study, and 286 consecutive patients were finally included. Among these patients, 181 had newly diagnosed cancer and 105 had nonmalignant diseases. Cancer was confirmed by biopsy. The severity of CAA was determined by coronary angiography and evaluated using the percentage of stenosis or Gensini scoring (GS). Patients with cancer versus cancer-free controls were older (OR = 1.052, 95% CI: 1.021-1.084, p < 0.001), more commonly male (OR = 0.048, 95% CI: 1.004-2.676, p=0.048), and more severely exposed to smoking (OR = 1.020, 95% CI: 1.007-1.033, p=0.003). Cancer patients were significantly more commonly complicated by ≥90% coronary stenosis than the gender- and age-matched cancer-free controls (9/93 versus 1/93, OR = 4.875, 95% CI: 1.024-23.213, p=0.047). After adjustment for age, gender, hypertension, diabetes, smoking history, blood glucose, and total cholesterol, cancer was significantly associated with high GS (adjusted OR = 2.208, 95% CI: 1.077-4.524, p=0.031). Our study demonstrated that cancer patients had increased CAA burden prior to cardiotoxic therapy. Further study is necessary to investigate the link between CAA and cancer.

Connexin 43 participates in atrial electrical remodelling through colocalization with calcium channels in atrial myocytes.

Atrial fibrillation (AF) is associated with atrial conduction disturbances caused by electrical and/or structural remodelling. In the present study, we hypothesized that connexin might interact with the calcium channel through forming a protein complex and, then, participates in the pathogenesis of AF. Western blot and whole-cell patch clamp showed that protein levels of Cav1.2 and connexin 43 (Cx43) and basal ICa,L were decreased in AF subjects compared to sinus rhythm (SR) controls. In cultured atrium-derived myocytes (HL-1 cells), knocking-down of Cx43 or incubation with 30 mmol/L glycyrrhetinic acid significantly inhibited protein levels of Cav1.2 and Cav3.1 and the current density of ICa,L and ICa,T . Incubation with nifedipine or mibefradil decreased the protein level of Cx43 in HL-1 cells. Moreover, Cx43 was colocalized with Cav1.2 and Cav3.1 in atrial myocytes. Therefore, Cx43 might regulate the ICa,L and ICa,T through colocalization with calcium channel subunits in atrial myocytes, representing a potential pathogenic mechanism in AF.

Quantitative late gadolinium enhancement cardiac magnetic resonance analysis of the relationship between ablation parameter and left atrial tissue lesion following pulmonary vein isolation.

Background: The impact of ablation parameters on acute tissue lesion formation after pulmonary vein isolation (PVI) has not been sufficiently evaluated in patients with atrial fibrillation. Radiofrequency ablation lesion can be visualized by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). We sought to quantitatively analyze the relationship between ablation parameter and tissue lesion following PVI at different segments of pulmonary vein (PV) using LGE-CMR. Methods: Twenty-one patients with atrial fibrillation who underwent PVI procedure were retrospectively enrolled. All patients underwent LGE-CMR examination within 3 days after radiofrequency ablation. Ablation parameters during PVI were documented, including lesion size index (LSI), force-time integral (FTI), power, contact force, temperature, and time of duration. The ablation point was projected onto 3-dimensional (3D) left atrial shell constructed base on LGE-CMR and corresponding image intensity ratio (IIR) was calculated on the same shell. A tissue lesion point was defined when the LGE-CMR IIR was > 1.2. Results: In total, 1,759 ablation points were analyzed. The ablation parameters and IIRs for each PV segment were significantly different (P < 0.0001). IIRs corresponding to ablation points at posterior of PV tended to be higher than those at non-posterior of PV when similar ablation parameters were applied during ablation. LSI was a better predictor of tissue lesion existence following PVI than FTI, contact force, power, temperature, and duration time at non-posterior wall of PV. The IIR showed positive correlation with LSI at non-posterior wall of PV (non-posterior of right PV, r = 0.13, P = 0.001, non-posterior of left PV, r = 0.26, P < 0.0001). Conclusion: When similar ablation parameters were applied during PVI, the posterior wall of PV had more severe tissue lesion than non-posterior wall of PV. Therefore, it was reasonable to decrease ablation energy at posterior wall of PV. Moreover, LSI was a better index to reflect tissue lesion quality following PVI at non-posterior of PV.

Shikonin suppresses colon cancer cell growth and exerts synergistic effects by regulating ADAM17 and the IL­6/STAT3 signaling pathway.

Signal transducer and activator of transcription 3 (STAT3) activation is associated with drug resistance induced by anti­epidermal growth factor receptor (anti­EGFR) therapy in the treatment of colon cancer. Thus, the combined inhibition of EGFR and STAT3 may prove beneficial for this type of cancer. STAT3 has been proven to play a critical role in colon cancer initiation and progression, and is considered the primary downstream effector driven by interleukin­6 (IL­6). A disintegrin and metalloproteinase 17 (ADAM17), documented as an oncogene, catalyzes the cleavage of both EGF and IL­6R, inducing EGFR signaling and enabling IL­6 trans­signaling to activate STAT3 in a wide range of cell types to promote inflammation and cancer development. As a natural product, shikonin (SKN) has been found to function as an antitumor agent; however, its role in the regulation of ADAM17 and IL­6/STAT3 signaling in colon cancer cells remains unknown. In the present study, it was found that SKN inhibited colon cancer cell growth, suppressed both constitutive and IL­6­induced STAT3 phosphorylation, and downregulated the expression of ADAM17. ADAM17 expression was not altered in response to STAT3 knockdown, while IL­6­induced STAT3 activation did not induce ADAM17 transcripts. Furthermore, it was demonstrated that SKN did not affect the expression of key proteins involved in the maturation and degradation of ADAM17. SKN decreased ADAM17 expression possibly through reactive oxygen species (ROS)­mediated translational inhibition, as evidenced by the increased ADAM17 mRNA and phosphorylation levels of eukaryotic initiation factor 2α (eIF2α). The expression of ADAM17 and p­eIF2α was reversed by N­acetylcysteine (NAC, a ROS scavenger). Taken together, these results indicate that the concurrent inhibition of ADAM17 and IL­6/STAT3 signaling by SKN may synergistically contribute to the suppression of colon cancer cell growth.