Cyanidin attenuates pressure overload-induced cardiac remodeling in mice via mitochondrial fusion enhancement

AIM To investigate the effect of cyanidin （Cyn） on pressure overload-induced cardiac remodeling and the underlying mechanism. METHODS Six-week-old male C57BL/6 mice （n=120） were divided into 4 groups： sham group （n=20）, sham+Cyn group （n=20）, transverse aortic constriction （TAC） group （n=40） and TAC+Cyn group （n=40）. The model of cardiac chronic pressure overload was induced by TAC, and the first day of TAC was defined as day 0. The animals in sham+Cyn group and TAC+Cyn group were treated with Cyn dissolved in DMSO and normal saline （5 mg·kg^-1·d^-1） for 5 d before TAC, while the animals in sham group and TAC group were treated with the same amount of DMSO and normal saline. Four weeks after TAC, the survival rate of the animals in each group was analyzed, the heart function of the mice was measured by ultrasound echocardiography, and the heart weight/body weight and lung weight/body weight were calculated. The cross-sectional area of the cardiomyocytes was measured by wheat germ agglutinin staining and hematoxylin-eosin staining. The degree of cardiac oxidative stress was evaluated by dihydroethidium staining and measurement of superoxide dismutase （SOD） and malondialdehyde （MDA） levels. The cardiomyocyte apoptosis was detected by TUNEL method. The mRNA expression levels of atrial natriuretic peptide （ANP）, brain natriuretic peptide （BNP） and β-myosin heavy chain （β-MHC） were detected by RT-qPCR, and the protein expression levels of Bax, Bcl-2, optic atrophy protein 1 （OPA1） and dynamin-related protein 1 （Drp1） were determined by Western blot. The mitochondrial morphological changes were observed by transmission electron microscopy. RESULTS Compared with TAC group, the survival rate of the mice in TAC+Cyn group was significantly increased （P<0.05）, the myocardial apoptosis, the cross-sectional area of myocardial cells, the heart weight/body weight, the lung weight/body weight, the level of reactive oxygen species and the MDA content were decreased （P<0.05）, and the SOD was activated （P<0.05）. M-mode ultrasound tests showed that Cyn treatment significantly increased left ventricular ejection fraction and left ventricular fractional shortening in the mice after TAC （P<0.05）, while left ventricular end-diastolic diameter and left ventricular posterior wall thickness in diastole were reduced （P<0.05）. Transmission electron microscopic observation showed that the number of myocardial mitochondria was increased and the mitochondrial area was decreased after TAC （P<0.05）, while treatment with Cyn increased the area of myocardial mitochondria and decreased the mitochondrial number （P<0.05）. Compared with sham group, the protein level of OPA1 in TAC group was significantly reduced （P<0.05）, while treatment with Cyn significantly increased the protein level of OPA1. CONCLUSION Cyanidin significantly increases the survival rate, improves the cardiac function and attenuates the cardiac remodeling of the mice after TAC. The mechanism may be related to the inhibition of myocardial mitochondrial OPA1 cleavage and the promotion of mitochondrial fusion.     

TMAO aggravates heart failure by promoting T-tubule remodeling in adult mouse cardiomyocytes

AIM To investigate the role of trimethylamine N-oxide （TMAO） in T-tubule in cultured adult mouse cardiomyocytes. METHODS T-tubule imaging was used to detect T-tubule network in cardiomyocytes. Ca²⁺ handling dysfunction was identified by confocal Ca²⁺ imaging. Tubulin densification and polymerization in the cardiomyocytes were assessed by Western blot and immunofluorescence staining. Echocardiography was used to detect cardiac function in the mice fed on TMAO and chow diet. RESULTS Compared with control group, the T-tubule density and T-tubule power of the mouse cardiomyocytes cultured with TMAO were significantly decreased (P<0.01). Compared with control group, the mean amplitude of Ca²⁺ transients in TMAO group was decreased (P<0.01), while the time to reach the Ca²⁺ transient peak and the dyssynchrony index increased (P<0.01). Compared with control group, the power of junctophilin-2 (JPH2） in the mouse cardiomyocytes treated with TMAO was decreased (P<0.01). Significant JPH2 accumulation was observed at the edge of the cardiomyocytes (P<0.01). Compared with control group, the microtubule density in TMAO group was significantly higher (P<0.01), and microtubule aggregation was enhanced (P<0.01). Compared with the mice in control group fed on a normal diet, the TMAO-fed mice had significantly lower systolic function and left ventricular ejection fraction (P<0.05). CONCLUSION TMAO impairs cardiac function via the promotion of tubulin polymerization, subsequent JPH2 translocation and T-tubule remodeling, which provides a novel mechanism for the relationship between heart failure and elevated TMAO.     

Effect of tanshinone ⅡA on liver lipid deposition and ferroptosis-related protein expression in ApoE-/- mice

AIM To observe the effect of tanshinone ⅡA on liver lipid deposition and ferroptosis-related protein expression in ApoE^-/- mice. METHODS Thirty-two ApoE^-/- mice were randomly divided into model group, high-dose (60 mg/kg) tanshinone ⅡA group, low-dose (30 mg/kg) tanshinone ⅡA group and simvastatin group, and C57BL/6J mice (n=8) were used as normal control group. The mice in normal control group were given the basic feeding, while the others were given high-fat diet. The mice in tanshinone ⅡA groups and simvastatin group were given corresponding drugs. The mice in normal control group and model group were intraperitoneally injected with equal volume of saline. Eight weeks later, the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were tested by automatic biochemistry analyzer. The liver tissues were stained with HE and oil red O. The contents of reactive oxygen species (ROS) and glutathione (GSH) in liver tissues of the mice were measured by commercially available kits. The liver glutathione peroxidase 4 (GPX4) and p53 were detected by immunohistochemical method. The protein and mRNA expression levels of ferroptosis-related factors GPX4, xCT/SLC7A11, p53 and ferritin heavy chain 1 (FTH1) were determined by Wes automatic Western blot quantitative analysis system and RT-qPCR. RESULTS Compared with normal control group, the serum levels of TC, TG and LDL-C in model group were increased significantly (P<0.05 or P<0.01), and HDL-C did not change significantly. The fat vacuoles were clearly visible in liver tissue. The content of ROS in liver tissue was increased significantly,and GSH was decreased significantly (P<0.01). The mRNA and protein expression levels of p53 were increased significantly, and GPX4, xCT/SLC7A11 and FTH1 were decreased significantly (P<0.05 or P<0.01). Compared with model group, tanshinone ⅡA significantly decreased the serum levels of TC, TG and LDL-C (P<0.05 or P<0.01), and HDL-C did not change significantly. High-dose and low-dose tanshinoneⅡA also significantly decreased the degree of steatosis, and the size of lipid droplets. The content of ROS in liver tissues was decreased significantly, and GSH was increased significantly (P<0.01). The mRNA and protein expression levels of GPX4, xCT/SLC7A11 and FTH1 were increased significantly, and p53 were decreased significantly (P<0.05 or P<0.01). CONCLUSION Tanshinone ⅡA reduces liver lipid deposition and lipid peroxidation damage in ApoE^-/- mice, which may be related to the intervention of ferroptosis-related proteins in the liver cells.     

Role and potential mechanism of fecal microbiota transplantation in treatment of chronic hepatitis B

AIM To investigate the effect of fecal microbiota transplantation （FMT） on the treatment of chronic hepatitis B （CHB） and the potential mechanism. METHODS Fifty C57BL/6J mice （6~8 weeks old） were divided into 5 groups： control group， CHB group， entecavir （ETV） group， comprehensive treatment （ETV+FMT， EFMT） group， and blocker （TAK-242+ETV+FMT， EFMT-TAK） group. The mice in each group were given corresponding treatment. The general condition of the mice was observed daily， and fecal specimens were kept every 10 d. The mice were sacrificed after 12 weeks， and the liver tissues and blood samples were collected. HE staining was used for histological scoring. Serum hepatitis B surface antigen （HBsAg） and interleukin-18 （IL-18） levels were measured by ELISA. Toll-like receptor 4 （TLR4） expression was detected by flow cytometry. Intestinal flora diversity was analyzed by high-throughput sequencing. RESULTS （1） Compared with control group， the body weight of the mice in CHB group was significantly reduced （P<0.05）. The body weight loss of the mice in ETV group， EFMT group and EFMT-TAK group was reversed to some extent as compared with CHB group （P<0.05）. （2） The histological score of the mice in CHB group was significantly higher than that in control group （P<0.05）. The score in ETV group was lower than that in CHB group （P<0.05）. The scores in EFMT group and EFMT-TAK group were lower than that in ETV group （P<0.05）， and that in EFMT-TAK group had a further downward trend compared with EFMT group （P<0.05）. （3） Compared with control group， the serum level of HBsAg in the CHB mice was significantly increased （P<0.05） and decreased after ETV treatment （P<0.05）. The HBsAg level in both EFMT group and EFMT-TAK group was significantly lower than that in ETV group （P<0.05）. （4） The IL-18 level in CHB group was significantly higher than that in control group （P<0.05）. After ETV treatment， the IL-18 level was decreased （P<0.05）， and that in both EFMT group and EFMT-TAK group was decreased more than that in ETV group （P<0.05）. （5） TLR4 expression in CHB group was higher than that in control group （P<0.05）， that in ETV group was lower than CHB group （P<0.05）， and that in EFMT group was further decreased （P<0.05）. （6） The heat map analysis at the class level showed that the abundances of Gammaproteobacteria， Deltaproteobacteria and Negativicutes in CHB group were significantly higher than those in control group， and those of Deltaproteobacteria and Negativicutes in EFMT group were close to those in control group. The heat map analysis at the family level indicated that the abundances of Burkholderiaceae， Desulfovibrionaceae and Veillonellaceae in CHB group were significantly higher than those in control group， while those in ETV group and EFMT group gradually approached normal levels. The α diversity index in CHB group was significantly decreased， while the diversity in ETV group was increased， that in EFMT group was further increased， and that in EFMT-TAK group was the highest. CONCLUSION FMT plays an active role in the treatment of CHB. The mechanism may be related to reducing the level of IL-18 and improving the structure and diversity of intestinal flora. The TLR4 signaling pathway is involved.     

Effects of cardiac contractility modulation on ventricular electrical remodeling in rabbits with chronic heart failure

AIM: To investigate the effects of cardiac contractility modulation (CCM) on ventricular electrical remodeling in a rabbit model of chronic heart failure. METHODS: The rabbits were divided into sham group, heart failure(HF) group and HF+ CCM group. The rabbit model of chronic heart failure was established by ligating the ascending aortic root. Then electrical stimulations during the absolute refractory period were delivered lasting 6 h everyday for 4 weeks in rabbits of HF+ CCM group. The QTc and ventricular effective refrective period (VERP) were recorded. The protein and mRNA levels of Kv1.4, Kv4.3 and connexin 43 (Cx43) were determined by Western blot and RT-qPCR. RESULTS: Compared with sham group, QTc were significantly prolonged in HF rabbits at week 12 (P<0.05). CCM therapy shortened QTc of rabbits with heart failure at week 16 (P<0.05). Compared with sham group, VERP significantly increased in HF group and HF+ CCM group, while CCM therapy shortened VERP of rabbits with heart failure at week 16 (P<0.05). Compared with sham group, the mRNA and protein levels of Kv1.4, Kv4.3 and Cx43 were decreased in HF group and HF+ CCM group (P<0.05). However, CCM therapy restored the mRNA and protein levels of Kv1.4, Kv4.3 and Cx43 of rabbits with heart failure (P<0.05). CONCLUSION: CCM suppresses ventricular electrical remodeling in heart failure and the underlying mechanism may be associated with increasing Kv1.4, Kv4.3 and Cx43 expression.     

草莓白化相关病毒中国分离物全基因组分析

草莓白化相关病毒(strawberrypallidosis-associatedvirus,SPa V)属于长线形病毒科(Closteroviridae)毛形病毒属(Crinivirus),可引起草莓病害,2017年在中国首次报道。采用高通量测序、RACE和RT-PCR技术获得了SPa V中国分离物(FJ)的基因组全长。该病毒含有两条正单链基因组RNA1和RNA2。RNA1全长8 048 nt,5′和3′非编码区序列分别为264和197 nt,含有3个开放阅读框(ORF),分别编码ORF 1a/1b融合蛋白和p9蛋白。RNA2全长7 977 nt,5′和3′非编码区序列分别为248和186 nt,含有8个开放阅读框(ORF),分别编码HSP70h、CPh、CP、CPm、p7、p6、p9和p28等8个蛋白。RNA1和RNA2与美国M1分离物分别具有98.5%和99.0%的核苷酸一致性;系统发育分析结果表明,SPa V中国分离物(FJ)单独处在一个分支。对SPa V来源的小RNA的分析表明,来源于SPa V的小RAN长度以21和22 nt为主。     

Inhibitory effect of Wendan decoction on atherosclerotic plaque formation in ApoE-/- mice by regulating expression of membrane proteins involved in reverse cholesterol transport

AIM To explore the anti-atherosclerotic mechanism of Wendan decoction based on reverse cholesterol transport. METHODS Eight-week-old apolipoprotein E gene knockout （ApoE^-/-） mice with high-fat diet and daily drug gavage were randomly divided into model group, simvastatin group, and low-, middle- and high-dose Wendan decoction groups, with 15 mice in each group. The C57BL/6 mice of the same age served as control group. The mice were weighed once every week. After 10 weeks, the mice were anesthetized with chloral hydrate. The serum were collected for lipid level examination. The atherosclerotic plaque buildup in aortic root and whole aorta was observed by HE staining and oil red O staining, respectively. The levels of proteins related to cholesterol transport, ATP-binding cassette transporter A1 （ABCA1） and caveolin-1 in the aorta, and scavenger receptor class B type I （SR-BI） and CD36 in the liver, were quantified by Western blot. RESULTS Wendan decoction at middle dose inhibited the increase in the body weight of ApoE^-/- mice fed with high-fat diet （P<0.05）. Wendan decoction at different doses significantly reduced the serum levels of triglyceride, total cholesterol and low-density lipoprotein cholesterol in the ApoE^-/- mice （P<0.05 or P<0.01）, but had no effect on serum high-density lipoprotein cholesterol level （P>0.05）. Wendan decoction at different doses inhibited the formation of atherosclerotic plaques in whole aorta of the ApoE^-/- mice （P<0.05 or P<0.01）. Middle- and high-dose Wendan decoction significantly inhibited the formation of atherosclerotic plaques in the aortic root （P<0.05）. Bedsides, Wendan decoction at different doses increased the protein level of ABCA1 and decreased the protein level of caveolin-1 in the aorta of the ApoE^-/- mice （P<0.01）. Middle- and high-dose Wendan decoction increased the liver protein level of SR-BI in the ApoE^-/- mice （P<0.01）. However, Wendan decoction at different doses had no effect on the liver protein level of CD36 in the ApoE^-/- mice （P>0.05）. CONCLUSION Wendan decoction reduces the body weight, serum lipid levels and formation of atherosclerotic plaques in ApoE^-/- mice fed with high-fat diet, and its mechanism is related to up-regulation of ABCA1 protein level in the aorta and SR-BI protein level in the liver as well as down-regulation of caveolin-1 protein level in the aorta.     

Prostaglandin E1 protects heart after myocardial infarction by inhibiting endoplasmic reticulum stress in rats

AIM To investigate the effect of prostaglandin E1 (PGE1) on heart after myocardial infarction (MI) in rats and its related molecular mechanism. METHODS Fifty male SD rats were divided into sham group, model group and model+PGE1 group. The MI rat model was established by ligation of left anterior descending coronary artery. Cardiac function in the rats was detected by echocardiogaphy. The myocardial histomorphologic changes were evaluated by HE and Masson staining. The MI area was measured by TTC staining. The cardiomyocyte death was detected by TUNEL staining. The protein levels of endoplasmic reticulum stress (ERS)-related factors glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and caspase-12, and apoptosis-related factors Bcl-2, Bax and cleaved caspase-3 were determined by immunofluorescence staining and Western blot. RESULTS Compared with sham group, the cardiac function in model group was decreased, with significant myocardial pathological changes. The MI area was enlarged， and the death of cardiomyocytes was promoted. The protein levels of GRP78, CHOP, caspase-12, Bax and cleaved caspase-3 in the myocardial tissues were significantly increased, while Bcl-2 was decreased (P<0.01). Compared with model group, the cardiac function in model+PGE1 group was significantly improved, and the myocardial pathological damage was significantlty attenuated. The MI area and myocardial cell death were significantly reduced. The protein levels of GRP78, CHOP, caspase-12, Bax and cleaved caspase-3 in the myocardial tissues were significantly decreased, while Bcl-2 was increased (P<0.01). CONCLUSION PGE1 reduces collagen deposition and inflammation, and improves cardiac function by reducing ERS level， thus protecting cardiomyocytes from MI damage.     

Effect of resveratrol on autophagy and renal interstitial fibrosis in kidney of diabetic mice

AIMTo observe the effect of resveratrol (Res) on renal autophagy level and renal interstitial fibrosis in the mice with diabetes mellitus (DM), and to discuss the possible mechanism. METHODSThe wild-type C57BL/6 mice were randomly divided into 3 groups, including normal control (NC) group, DM group and Res group (8 in each group). The diabetic mouse model was established by injection of streptozotocin. After 8 weeks of successful replication of the diabetic model, Res was given to the mice in Res group by continuous gavage for 12 weeks, and then the mice in each group were sacrificed to detect the relevant biochemical parameters. The pathological changes of the kidney tissues were observed by HE staining and Masson staining. The levels of the proteins related to autophagy, epithelial-mesenchymal transition (EMT) and fibrosis were determined by Western blot. The mRNA expression of collagen type IV (Col IV), α-smooth muscle actin (α-SMA) and E-cadherin were detected by real-time PCR. RESULTSCompared with NC group, fasting blood glucose (FBG), kidney index (KI), serum creatinine, 24-hour urinary albumin excretion rate and 24-hour urine total protein were remarkably increased in DM group (P<0.05). The results of HE and Masson staining indicated that renal tissue presented fibrosis in DM group. The protein levels of E-cadherin, beclin-1, microtubule-associated protein 1 light chain 3-II (LC3-II) were reduced in DM group, while the levels of α-SMA, Col IV and Snail1 were increased (P<0.05). After intervention with Res for 12 weeks, all the relevant biochemical parameters and KI were reduced (P<0.05) except FBG (P>0.05), and renal fibrosis lesions were obviously alleviated. Compared with DM group, the protein levels of E-cadherin, beclin-1 and LC3-II were increased in Res group, but the protein expression levels of α-SMA, Col IV, Snail1 were reduced (P<0.05). Compared with DM group, the mRNA level of E-cadherin was increased in Res group , but the mRNA levels of Col IV and α-SMA were reduced (P<0.05). CONCLUSION Resveratrol significantly inhibits EMT and reduces renal interstitial fibrosis in diabetic mice, and its mechanism may be related to the promotion of renal autophagy.     

朱顶红无菌苗叶片高效再生体系

以朱顶红（Hippeastrum vittatum）叶片为外植体进行离体培养，具有取材方便、试材充足、成本低等优势，但叶片诱导再生率极低，是朱顶红离体培养的一大难题。本试验中分别以‘花孔雀’和‘黑天鹅’朱顶红无菌苗叶片为外植体，探究了不同植物生长调节剂和不同取材部位对不定芽诱导和继代增殖的影响。结果表明：最佳外植体为 MS 培养基中培养 10 d 形成的幼嫩叶片基部（0.5 cm），在光照 16 h · d-1（光照强度 36 μmol · m-2 · s-1）下，不定芽诱导的最适培养基为 MS + 2 mg · L-1 6-BA + 1 mg · L-1 NAA + 2 mg · L-1 TDZ，两个品种的不定芽均以间接途径发生，其中‘花孔雀’在培养 40 d 后形成愈伤组织，55 d形成不定芽，诱导率可达 69.44%；‘黑天鹅’在培养 45 d 后形成愈伤组织，65 d 形成不定芽，诱导率达到 66.67%；最适体细胞胚诱导培养基为 MS + 2 mg · L-1 6-BA + 1 mg · L-1 PIC，‘花孔雀’和‘黑天鹅’的诱导率分别达到 66.67%和 63.89%；最佳不定芽增殖培养基为 MS + 2 mg · L-1 6-BA + 1 mg · L-1 NAA + 1 mg · L-1 TDZ，‘花孔雀’和‘黑天鹅’的增殖系数分别达到 4.67 和 3.46；在不添加植物生长调节剂的 MS培养基中进行生根培养，30 d 后两个品种的生根率均达到 100%；将生根培养 30 d 的小植株转移至室温条件下放置 3 d，摘去封口膜再驯化 3 d 后，移栽至经高温消毒的草炭︰蛭石（体积比）为 1︰1 的基质中，成活率达到 100%     

Aberrant SYK expression in cholangiocarcinoma and its effect on M2 macrophage polarization in tumor microenvironment

AIM To investigate the expression of spleen tyrosine kinase (SYK) in 2 murine cholangiocarcinoma (CCA) progressive models and human CCA tissues, and to explore the effects of SYK expression on the polarization of M2 macrophages. METHODS SD rats were given drinking water containing thioacetamide (TAA) daily. BALB/c mice were treated with left median bile duct ligation combined with diethylnitrosamine (DEN) administration. The expression of SYK and M2 macrophage infiltration (CD163) in the animals and human CCA tissues were detected by immunohistochem?istry, and their correlation was analyzed. Ten SD rats, which were given drinking water containing TAA daily for 24 weeks, were randomly divided into control group (n=5) and SYK inhibitor group (n=5). After the rats received SYK inhibitor through gavage for 4 weeks, the effects of SYK inhibitor on tumor growth and macrophage polarization were analyzed. RESULTS The hepatic bile duct hyperplasia, dysplasia (or cholangioma), and CCA occurred at different time points in the rats and mice. During the development of CCA, SYK expression was gradually increased (P<0.01), accompanied by enhanced infiltration of M2 macrophages, while the M1 macrophages were decreased in the hepatic bile duct tissues (P<0.01). SYK and CD163 expression levels were significantly up-regulated (P<0.01), and a positive correlation (r=0.57, P<0.01) in human CCA tissues was observed. In the rat CCA model, the number of tumor nodules and infiltration of M2 macrophages in SYK inhibitor group were decreased compared with its control group (P<0.01). CONCLUSION In the murine CCA models, SYK expression was progressively increased during the evolution of CCA, which may promote tumor progression via the polarization of M2 macrophages, and SYK inhibitor effectively inhibits the tumor growth and M2 macrophage polarization in the rat CCA model.     

Effect of wogonoside on inflammatory response in mice with viral myocarditis induced by Coxsackie virus B3

AIM: To investigate the effect of wogonoside on the inflammatory response of mice with Coxsackie virus B3 (CVB3)-induced myocarditis and its possible regulatory mechanism. METHODS: A mouse model of viral myocarditis was constructed by infecting BALB/c mice with CVB3. BALB/c mice (n=40) were randomized into 4 groups: normal group, CVB3-induced viral myocarditis group, CVB3-induced viral myocarditis combined with wogonoside treatment group and CVB3-induced viral myocarditis combined with wogonoside plus AKT agonist treatment group. All the mice were sacrificed 7 days after treatment. In the first 3 groups, HE staining was applied to detect the infiltration of inflammatory cells in the myocardium, ELISA was applied to detect the serum levels of interleukin-1β (IL-1β) and IL-6, while Western blot was applied to detect the protein expression of inflammatory factors and the activation of AKT/NF-κB pathway. Inaddition, the activation of AKT/NF-κB pathway in the 4 groups was detected by Western blot analysis. RESULTS: HE staining showed that there was a large amount of inflammatory cell infiltration in the myocardium of CVB3-induced viral myocarditis mice, as compared with the normal group, which was significantly reduced by wogonoside treatment (P<0.05). The serum levels of IL-1β and IL-6 in the mice after CVB3 infection were significantly higher than those in normal group (P<0.05), which was also significantly reduced by wogonoside treatment (P<0.05). Western blot analysis indicated that wogonoside treatment significantly reduced the expression of inflammatory factors IL-1β and IL-6, and the phosphorylation of AKT/NF-κB pathway-related proteins in the myocardial tissue (P<0.05). After administration of AKT agonist, the inhibitory effect of wogonoside on NF-κB phosphorylation and inflammatory factors expression was significantly eliminated (P<0.05). CONCLUSION: Wogonoside attenuates the inflammatory response of mice with viral myocarditis by inhibiting the AKT/NF-κB pathway.     

Effects of P38 MAPK signaling pathway on anacardic acid attenuating mouse cardiomyocyte hypertrophy induced by phenylephrine

AIM: To investigate the roles of P38 mitogen-activated protein kinase (P38 MAPK) in the process of anacardic acid (AA) attenuating mouse cardiomyocyte hypertrophy induced by phenylephrine (PE). METHODS: Cardiomyocyte hypertrophy was induced by PE in primary neonatal mouse myocardial cells. According to random number table method, the experiments were designed in 6 groups as following: control group, PE+ DMSO group, PE group, PE+ AA group, PE+ AA+ P38 inhibitor group and PE+ P38 inhibitor group. Mouse myocardial cells were collected after intervention for 48 h. The protein levels of p-P38, acetylated histone H3 at lysine 9 (H3K9ac) and atrial natriuretic peptide (ANP) were determined by Western blot. The interaction between p-P38 and H3K9ac was verified by co-immunoprecipitation (Co-IP). The mRNA expression of myocyte enhancer factor 2C (MEF2C) were tested by RT-qPCR. Mouse myocardial cell surface area was observed by immunofluorescence staining. RESULTS: The results of Western blot showed that the protein levels of p-P38 and H3K9ac in PE group were significantly increased compared with control group (P<0.05), and the levels of MEF2C mRNA and ANP protein in PE group were apparently increased compared with control group (P<0.05). However, P38 inhibitor and histone acetylase inhibitor AA attenuated P38 phosphorylation and H3K9 acetylation induced by PE, and down-regulated the over-expression of MEF2C and ANP in the mouse myocardial cells (P<0.05). The results of immunofluorescence staining showed that PE apparently increased mouse myocardial cell surface area (P<0.05), while P38 inhibitor and AA attenuated cardiomyocyte hypertrophy induced by PE (P<0.05). CONCLUSION: The mechanism of AA attenuating cardiomyocyte hypertrophy induced by PE may be related to the regulation of histone acetylation modification imbalance mediated by P38 MAPK signaling pathway.     

CYP450 epoxygenase/EET pathway attenuates adipose inflammation of obese mice through HIF-1α

AIM To investigate the effects of cytochrome P450 （CYP450） epoxygenase/epoxyeicosatrienoic acid （EET） pathway on insulin resistance in obese mice， and to explore the possible mechanisms. METHODS High-fat diet-induced obesity model was established in C57BL/6Cnc mice， and the obese mice were randomly divided into 3 groups， including obesity group （treated with saline； n=10）， EET group （treated with 11，12-EET； n=10） and EET inhibitor 14，15-epoxyeicosa-5（Z）-enoic acid （EEZE） group （n=10）. Normal C57BL/6Cnc mice （n=10） treated with saline served as control. Protein expression of CYP2J2 （one of CYP450 epoxygenases） and hypoxia-inducible factor-1α （HIF-1α） was measured by Western blot. Vessel-like structure was detected by immunofluorescence staining. The serum levels of insulin， tumor necrosis factor-α （TNF-α）， interleukin （IL）-1β， IL-6 and monocyte chemoattractant protein-1 （MCP-1） were measured by ELISA. RESULTS In obese mice， homeostasis model assessment of insulin resistance （HOMA-IR） values were increased， the protein level of CYP2J2 was reduced， and the protein level of HIF-1α was increased in adipose tissues as compared with the controls （P<0.05）. The serum levels of MCP-1， IL-1β， IL-6 and TNF-α were also significantly increased in obese mice （P<0.05）. After treatment with 11， 12-EET， the HOMA-IR values were decreased compared with vehicle-treated obese mice， HIF-1α expression levels were decreased in the adipose tissue， and the serum levels of MCP-1， IL-1β， IL-6 and TNF-α were reduced （P<0.05）. Immunohistochemical results of adipose tissue from vehicle-treated obese mice showed a marked decrease in vessel-like structures （CD31-positive） compared with normal control mice （P<0.05）. EET treatment significantly increased the newly formed vessel-like structures in the visceral adipose tissues of obese mice as compared with vehicle-treated obese mice （P<0.05）. CONCLUSION High-fat diet-induced obesity and insulin resistance are closely related to the CYP450 pathway. Exogenous EETs effectively decrease obesity-induced insulin resistance possibly through pro-angiogenesis and attenuation of hypoxia and inflammation.     

Expression of melusin in myocardial tissues with different degrees of coronary atherosclerosis

AIM: To observe the pathological changes of myocardial tissues with different degrees of coronary atherosclerotic lesions, and to detect the level of melusin in myocardial tissue for exploring the role of melusin in the deve-lopment of coronary heart disease. METHODS: The cases of coronary heart disease were confirmed by autopsy and histopathological examination, and were classified into 3 groups: coronary atherosclerotic stable plaques (B group); atherosclerotic unstable plaques without thrombosis, plaque rupture, plaque hemorrhage and other secondary changes (C group); atherosclerotic unstable plaques with any of the secondary changes mentioned above (D group). The control group (A group) had no lesion of coronary artery. The coronary and myocardial tissues were collected separately, and routine HE staining of paraffin sections was performed to observe the histological structure of myocardium. The expression of melusin was detected by immunohistochemical staining, Western blot and real-time PCR. Logistic regression analysis was used to analyze the relationship between melusin expression changes and the development of coronary heart disease. RESULTS: Compared with A group, human cardiac myocytes showed pathological changes such as hypertrophy, atrophy, necrosis and adipose tissue infiltration in the other 3 groups. The expression of melusin in C and D groups was significantly lower than that in control group, while the expression of melusin was increased in B group (P<0.05). The expression of melusin in myocardial tissues was negatively correlated with the development of coronary heart disease (OR=0.3; 95% CI: 0.2~0.4; P<0.01). CONCLUSION: Melusin in human myocardial tissue may be a protective factor of heart in coronary heart disease. It plays an important role in the development of coronary heart disease.     

Effect of recombinant plasmids encoding IL-1RII and IL-1RAcP on rat experimental autoimmune myocarditis and possible mechanism

AIM To evaluate the effects of recombinant plasmids encoding interleukin-1 type II receptor （IL-1RII） and interleukin-1 receptor accessory protein （IL-1RAcP） on rat experimental autoimmune myocarditis （EAM） and the possible mechanism. METHODS The recombinant plasmids pCAGGS-IL-1RII and pCAGGS-IL-1RAcP were constructed， and pCAGGS-SP （signal peptide） served as the control plasmid. Male Lewis rats （n=29） were divided into 4 groups： control group （rats without immunization or injection， n=5）， EAM+SP group （immunized rats injected with pCAGGS-SP， n=9）， EAM+IL-1RII group （immunized rats injected with pCAGGS-IL-1RII， n=8） and EAM+IL-1RII+IL-1RAcP group （immunized rats injected with pCAGGS-IL-1RII and pCAGGS-IL-1RAcP， n=7）. The rats were immunized to induce EAM on day 0， and injected with recombinant plasmids by hydrodynamics-based delivery on day 6. Echocardiography was performed， and the rats were killed on day 17. The ratio of heart weight to body weight （HW/BW） was evaluated， and the histopathological changes of the myocardial tissues were observed by HE staining. The mRNA expression of atrial natriuretic peptide （ANP）， brain natriuretic peptide （BNP） and inflammatory factors in the myocardial tissues was detected by RT-qPCR. Recombinant plasmids pUC19-IL-1RII-actin and pUC19-IL-1RAcP-tub were transfected into Cos7 cells， and the culture supernatants were collected and added to lipopolysaccharide （LPS）-induced H9c2 cells. The expression of inflammatory genes were detected by RT-qPCR. Recombinant plasmids pEGFP-IL-1RII-actin and pEGFP-IL-1RAcP-tub were transfected into the Cos7 cells to identify the formation of IL-1RII/IL-1RAcP heterodimer by co-immunoprecipitation （Co-IP）. RESULTS Compared with EAM+SP group， injection with plasmids effectively attenuated EAM in EAM+IL-1RII group and EAM+IL-1RII+IL-1RAcP group， as indicated by the decreases in HW/BW， left ventricular end-systolic diameter， and myocardial expression of ANP， BNP， TNF-α， IL-2， IFN-γ and TGF-β， and the increase in expression of IL-4 in the hearts. In LPS-induced H9c2 cells， compared with LPS group， the levels of TGF-β and IL-6 in the culture supernatants were significantly decreased （P<0.01）， and the level of IL-10 was significantly increased （P<0.05） in LPS+IL-1RII group and LPS+IL-1RII+IL-1RAcP group. Compared with LPS+IL-1RII group， the expression of TNF-α and IL-2 was significantly decreased （P<0.05）， and the expression of IL-13 was significantly increased in LPS+IL-1RII+IL-1RAcP group （P<0.01）. The formation of IL-1RII/IL-1RAcP heterodimer was detected by Co-IP. CONCLUSION Plasmids encoding IL-1RII and IL-1RAcP effectively attenuate EAM， and the possible mechanism may be related to the inhibition of inflammatory factor expression and the formation of IL-1RII/IL-1RAcP heterodimer.     

Niflumic acid inhibits the proliferation,migration and invasion of glioma U87 cells

AIM To investigate the effect of niflumic acid （NFA） on human glioma U87 cells and to clarify the potential mechanism. METHODS The U87 cells were cultured in vitro and divided into blank control group， and 50， 100 and 200 μmol/L NFA groups. MTT assay was performed to determine the viability of cells in various groups. Migration and invasion abilities were measured by real-time cell analysis （RTCA）. RESULTS The results of MTT assay showed that compared with blank control group， the viability of U87 cells was increased after treatment with NFA for 12 h （P<0.05 or P<0.01）， while the viability was significantly decreased after treatment with NFA for 24 and 48 h （P<0.05 or P<0.01） in a concentration-dependent manner. The results of RTCA showed that compared with control group， the cell migration and invasion abilities were inhibited in 100 and 200 μmol/L NFA groups （P<0.05 or P<0.01） and the inhibitory effects were more obvious in 200 μmol/L NFA group （P<0.01）. CONCLUSION NFA inhibits the viability， migration and invasion of human glioma U87 cells.     

IL-33-modified BMSCs attenuate acute kidney injury induced by sepsis in rats through MyD88

AIM To investigate the effect of interleukin-33 (IL-33)-modified bone marrow mesenchymal stem cells (BMSCs) on sepsis-induced acute kidney injury (AKI) in rats and the expression of myeloid differentiation factor 88(MyD88). METHODS A septic rat model was established by cecal ligation and puncture. The SD rats (n=80) were randomly divided into control group, model group, negative transfection group (transplanting untransfected BMSCs) and IL-33 transfection group (transplanting BMSCs transfected with IL-33), with 20 in each group. Survival rates of the rats within 72 h in the 4 groups were compared. Serum creatinine (SCr) and blood urea nitrogen (BUN) levels were measured before, and 24, 48 and 72 h after transplantation. The kidney pathological damage was observed by HE staining, and the apoptosis of renal cells was detected by TUNEL method 72 h after transplantation. Western blot was used to detect the protein expression levels of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), Toll-like receptor 4 (TLR4) and MyD88. RESULTS The survival rate of the rats in model group was significantly lower than that in control group (P<0.05). The survival rate of the rats in IL-33 transfection group was higher than that in model group and negative transfection group (P<0.05). The levels of SCr and BUN in model group were higher than those in control group (P<0.05). The levels of SCr and BUN in IL-33 transfection group were significantly reduced after transplantation, and were lower than those in model group and negative transfection group (P<0.05). The renal tissue pathological injury score in model group was significantly higher than that in control group (P<0.05). Compared with model group and negative transfection group, the renal tissue pathological injury score in IL-33 transfection group was significantly reduced (P<0.05). The proportion of apoptotic cells in the kidney tissues in model group were higher than that in control group (P<0.05). Compared with model group and negative transfection group, the proportion of apoptotic cells in the kidney tissues in IL-33 transfection group was significantly reduced (P<0.05). The protein expression levels of IL-1β, IL-6, TNF-α, TLR4 and MyD88 in model group were significantly higher than those in control group (P<0.05). Compared with model group and negative transfection group, the protein expression levels of IL-1β, IL-6, TNF-α, TLR4 and MyD88 in IL-33 transfection group were significantly decreased (P<0.05). CONCLUSION IL-33 gene-modified BMSCs significantly improve the renal function of AKI rats with sepsis. The mechanism may be related to IL-33 regulating TLR4/MyD88 signaling pathway and inhibiting renal inflammatory response.