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.     

RXRα agonist bexarotene inhibits atherosclerosis in ApoE-/- mice by regulating TGF-β1/Smad2 signaling pathway

AIM To observe the effect of retinoid X receptor α （RXRα） agonist bexarotene （Bex） on the proliferation of transforming growth factor β1 （TGF-β1）-induced vascular smooth muscle cells （VSMCs） and atherosclerosis in apolipoprotein E knockout （ApoE^-/-） mice， and to explore the underlying mechanism. METHODS Ten C57BL/6 mice were selected as normal control group， and 30 ApoE^-/- mice were randomly divided into 3 groups： ApoE^-/- group， ApoE^-/-+Bex5 （5 mg·kg^-1·d^-1 Bex） group and ApoE^-/-+Bex10 （10 mg·kg^-1·d^-1 Bex） group. Bex was intragastrically given once a day for 8 weeks. The levels of triglyceride （TG） and total cholesterol （TC） were determined by oxidase method， and select masking method was used to determine serum levels of low-density lipoprotein cholesterol （LDL-C） and high-density lipoprotein cholesterol （HDL-C）. The protein levels of TGF-β1， p-Smad2 and Smad2 were determined by Western blot. HE staining was used to observe the intima of the thoracic aorta. The VSMCs were cultured with tissue patch method， and the proliferation of VSMCs was measured by BrdU incorporation method. RESULTS The serum levels of TG， TC and LDL-C， and the expression of TGF-β1 and p-Smad2 in thoracic aorta in ApoE^-/- group were significantly higher than those in C57BL/6 group （P<0.01）. Bex increased p-Smad2 protein level in thoracic aorta in a dose-dependent manner， inhibited the intimal plaque formation and vascular medial proliferation， and decreased the plaque area in ApoE^-/- mice （P<0.01）. No significant difference in serum levels of TG， TC， HDL-C and LDL-C， and TGF-β1 and Smad2 expression in thoracic aorta among ApoE^-/- group， ApoE^-/-+Bex5 group and ApoE^-/-+Bex10 group was observed. TGF-β1 （0.1~10 μg/L） promoted the proliferation of VSMCs， while Bex （10^-9~10^-7 mol/L） inhibited TGF-β1 （5 μg/L）-induced proliferation of VSMCs in a concentration-dependent manner. Bex （10^-7 mol/L） synergistically promoted the protein level of p-Smad2 in VSMCs induced by TGF-β1 （P<0.01）， but inhibited TGF-β1-induced nuclear translocation of p-Smad2. CONCLUSION RXRα agonist Bex inhibits the formation of atherosclerosis in ApoE^-/- mice， and its mechanism may be related to the regulation of TGF-β1/Smad2 pathway.     

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.     

Correlation between progression of atherosclerosis accelerated by emotional stimulation and imbalance of SDF-1/CXCR4 in mice

AIM To observe effects of emotional stimulation on expression of stromal cell-derived factor-1（SDF-1） and CXC chemokine receptor 4 （CXCR4） in plasma, platelets, aortas, hippocampus and bone marrow of apolipoprotein E gene knockout （ApoE^-/-） mice, and to reveal the possible mechanism of the aggravated atherosclerotic plaque vulnerability by emotional stimulation. METHODS Thirty 8-week-old male ApoE^-/- mice were randomly divided into normal control group, high fat group, and emotional stimulation group. Ten 8-week-old inbred C57BL/6J mice served as blank control group. After 12 weeks of intervention, the serum levels of SDF-1 and CXCR4 were investigated by ELISA. The protein levels of SDF-1 and CXCR4 in platelets, aortas, hippocampus and bone marrow were determined by Western blot. The pathological damage of aortas was observed by oil red O staining. RESULTS Compared with blank control group, normal control group and high fat group, the mice subjected to emotional stimulation showed more serious atherosclerosis in aortas detected by oil red O staining, and increased levels of SDF-1 and CXCR4 in the plasma and aortas were also observed （P<0.05）. The results of Western blot showed that the protein levels of SDF-1 and CXCR4 in platelets, aortas and hippocampus were increased in the mice subjected emotional stimulation, but the expression of SDF-1 and CXCR4 in the bone marrow was decreased （P<0.05）. CONCLUSION Imbalance of SDF-1/CXCR4 may be the key target by which emotional stimulation accelerates the progression of atherosclerosis.     

Activation of PPARs is involved in effect of bezafibrate on diabetic hepatopathy in mice

AIM: To investigate the effects of bezafibrate (BEZ) on diabetic hepatopathy in mice. METHODS: Diabetic hepatopathy model was established by a long-high-energy diet combined with streptozotocin (40 mg·kg^-1·d^-1× 5 d, ip), and then bezafibrate (75 mg·kg^-1·d^-1, ig) was supplemented for 4 weeks. Fasting blood glucose (FBG) was detected every week. The structure of liver was observed by HE staining, and the liver function was measured by observing the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Total cholesterol (TC), triglyceride (TG), insulin and HbA1c were determined by commercial kits, and then HOMA insulin resistance index (HOMA-IR) was calculated. The expression of peroxisome proliferator-activated receports (PPARs) at mRNA and protein levels was determined by RT-qPCR and Western blot, respectively. RESULTS: After 7 days of treatment with streptozotocin, the FBG level of the mice exceeded 11.1 mmol/L. At the end of the experiment, the structural deformation of the hepatocytes (containing abundant fat vacuoles, infiltrated by inflammatory cells, etc.) was observed, with the increases in insulin, HbA1c, HOMA-IR, TC, TG, ALT and AST in diabetic mice (P<0.01). Meanwhile, the expression of PPARα, PPARβ and PPARγ at mRNA and protein levels was decreased (P<0.01). Bezafibrate treatment markedly attenuated the structural and functional damages of the liver in the diabetic mice (P<0.01), and reduced the levels of FBG, insulin, HbA1c, HOMA-IR, TC and TG (P<0.05). Bezafibrate also up-regulated the expression of PPARα, PPARβ and PPARγ (P<0.01). CONCLUSION: Bezafibrate attenuates hepatic injury in diabetic mice via the activation of PPARs-related signaling pathway.     

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.     

Immunomodulatory effect of Sema4D on Th1/Th2 in asthmatic rats induced by RSV and intervention of Kechuanning oral liquid

AIM To explore the effect of semaphorin 4D (Sema4D) on the immune regulation of Th1/Th2 in asthmatic rats induced by respiratory syncytial virus (RSV) and the effect of Kechuanning (KCN) intervention on the asthmatic rats. METHODS Healthy SPF female Wistar rats (n=100) were randomly divided into 10 groups: normal group, model group, Sema4D group, Sema4D antibody group, low, middle and high doses of KCN groups, and Sema4D+low, middle and high doses of KCN groups. Except the rats in normal group, the other rats were treated with RSV combined with ovalbumin (OVA) to induce asthmatic model. The pathological changes of the lung tissue were observed by HE staining, and the levels of interleukin-4 (IL-4), IL-6, IL-8, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in bronchoalveolar lavage fluid (BALF) were measured by ELISA. RESULTS Inflammatory cell infiltration and inflammatory damage in lung tissues of the rats in model group, Sema4D group and Sema4D+low dose of KCN group were observed by HE staining, while these pathological changes were attenuated in Sema4D antibody group， low, middle and high doses of KCN groups, and Sema4D+middle and high doses of KCN groups. Compared with normal group, the levels of IL-4, IL-6, IL-8 and TNF-α in BALF of the rats in the other groups were significantly increased, and the level of IFN-γ was significantly lowered (P<0.05 or P<0.01). Compared with model group, the levels of IL-4, IL-6, IL-8 and TNF-α in Sema4D group were increased, and the content of IFN-γ was decreased (P<0.05 or P<0.01). Compared with model group, the levels of IL-4, IL-6, IL-8 and TNF-α in Sema4D antibody group, low, middle and high doses of KCN groups, and Sema4D+low, middel and high doses of KCN groups were significantly decreased (P<0.01), while the content of IFN-γ was significantly increased (P<0.05 or P<0.01). No significant difference among Sema4D antibody group, Sema4D+middle and high doses of KCN groups, and low, middle and high doses of KCN groups was observed (P>0.05). CONCLUSION Sema4D causes Th1/Th2 immune imbalance and aggravates asthma. Inhibition of Sema4D reduces the production of inflammatory factors and regulates the balance of Th1/Th2. KCN may attenuate RSV-induced immune inflammation of asthmatic rats by inhibiting Sema4D, so as to achieve the anti-asthma effect.     

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.     

SUMO-specific protease 3 aggravates CaPO4-induced mouse abdominal aortic aneurysm formation by promoting macrophage polarization

AIMTo investigate the role of SUMO-specific protease 3 (SENP3) in macrophage polarization and calcium phosphate (CaPO₄)-induced abdominal aortic aneurysm (AAA) formation in mice. METHODS（1） Bone marrow-derived monocytes (BMDMs) in Senp3^flox/flox (wild-type, WT) mice and Senp3^flox/flox; Lyz2-Cre (monocyte-specific SENP3 knockout, i.e. conditioned knockout, cKO) mice were isolated and induced for M1 and M2 polarization. The mRNA and protein expression level of SENP3 were detected by RT-qPCR, Western blot and immunocytofluorescence, and the differential distribution of M1/M2 BMDMs from WT and cKO mice was analyzed. （2） CaPO₄ was administrated to induce AAA model in 8~12-week-old male WT and cKO mice. The AAA incidence, survival rate and maximal aortic diameter were analyzed between the 2 groups. Aortic aneurysm tissues were collected for pathological analysis, and the expression levels of SENP3, interleukin-1β (IL-1β), tumor necrosis factor-α (TNFα), IL-6 and matrix metalloproteinases-9 (MMP-9) were measured by RT-qPCR and Western blot. Dihydroethidium staining in situ in frozen sections was used to analyze the production of reactive oxygen species (ROS). （3） To explore the potential mechanisms, Western blot and co-immunoprecipitation were used to verify the de-SUMO modification of mitogen-activated protein kinase kinase 7 (MKK7) induced by SENP3. Besides, BMDMs were transfected with Flag-MKK7 wild type (Flag-MKK7 WT) and SUMO-modified site K18 mutant (Flag-MKK7 K18R mutant), and then M1 polarization of the cells was induced. The protein levels of p-JNK and MMP-9 in the 2 groups were determined by Western blot. RESULTS(1) SENP3 expression was up-regulated in M1 polarized macrophages (P<0.01), but was down-regulated in M2 polarized macrophages (P<0.01). The expression of SENP3 was decreased during the transformation of M1 to M2 in the macrophages (P<0.01), but was significantly up-regulated during the opposite process (P<0.01). Besides, more M1 macrophages and less M2 macrophages after induction were observed in the BMDMs from cKO mice than those from WT mice. (2) SENP3 expression was up-regulated in AAA tissues (P<0.05). The AAA incidence of cKO mice was significantly reduced after CaPO₄ induction (P<0.01), the survival rate was significantly improved (P<0.05), and maximal aortic diameter was significantly reduced in cKO group (P<0.01). The levels of IL-1β, IL-6 and TNFα, and the production of ROS were significantly down-regulated (P<0.01), meanwhile MMP-9 expression was also down-regulated in cKO mice (P<0.05). (3) the SUMO2/3 modification of MKK7 was reduced during M1 polarization, and MKK7 interaction with SENP3 was enhanced. Significantly up-regulated protein level of p-JNK and MMP-9 were verified in the M1 macrophages transfected with Flag-MKK7 K18R mutant (P<0.05). CONCLUSION SENP3 activates the MAPK/JNK pathway via de-SUMOylation of MKK7, regulates the M1/M2 polarization of macrophages and promotes the protein level of MMP-9, thus aggravating AAA formation.     

Effect of forsythiaside A on immune function in rats with ulcerative colitis

AIM To investigate the effect of forsythiaside A (FA) on immune function in rats with ulcerative colitis and its related mechanism. METHODS Healthy SD rats were randomly divided into 5 groups: control group (no treatment, normal feeding), model group (establishment of rat ulcerative colitis model), and low, medium and high doses of FA groups (treatment of the model rats with FA at 5 mg/kg, 20 mg/kg and 80 mg/kg, respectively). The malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in rat colon tissues were measured by colorimetry, and the serum levels of tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2) and IL-4 were detected by ELISA. The spleen index and thymus index, the percentages of CD3⁺, CD4⁺ and CD8⁺ T-lymphocytes in peripheral blood mononuclear cells （PBMC）, the serum IgA and IgG levels, and the serum complement C3 and C4 levels were also determined. RESULTS The colon tissues of the rats in model group showed obvious inflammation and ulceration, indicating that the animal model was successfully established. Compared with model group, the colonic inflammation and ulceration were significantly attenuated in FA groups, among which the high dose had the best effect. Compared with control group, the spleen index and thymus index of the rars in model group were decreased (P<0.05), MDA content in colon tissues was increased (P<0.05), and SOD activity in colon tissues was decreased (P<0.05). The levels of CD3⁺, CD4⁺, CD8⁺ and CD4⁺/CD8⁺ T-lymphocytes in PBMC, and the serum levels of C3, C4 and IL-4 were decreased (P<0.05), while the serum levels of IgA, IgG, TNF-α, and IL-2 were increased in model group as compared with control group. Furthermore, the spleen index and thymus index of the rats in FA groups were increased (P<0.05), the MDA content in the colon tissues was decreased (P<0.05), and the SOD activity in the colon tissues was increased (P<0.05). The levels of CD3⁺, CD4⁺, CD8⁺ and CD4⁺/CD8⁺ T-lymphocytes in PBMC, and the serum levels of C3, C4 and IL-4 were increased (P<0.05), while serum IgA, IgG, TNF-α and IL-2 levels were decreased in FA groups as compared with model group (P<0.05). CONCLUSION Forsythiaside A effectively attenuates the colonic lesions in rats with ulcerative colitis, and its mechanism may be related to reinforcement of oxygen free radical scavenging power, alleviation of inflammatory response, and enhancement of immune function.     

Sinomenine reduces MPP+-induced damage in SK-N-SH cells via ANRIL/miR-626 signaling pathway

AIM To investigate the effect of sinomenine (SN) on the damage of human neuroblastoma SK-N-SH cells induced by 1-methyl-4-4 phenylpyridine (MPP⁺) and its mechanism for exploring the pathogenesis of Parkinson disease. METHODS SN was used to treat MPP⁺-induced SK-N-SH cells. The levels of malondialdehyde (MDA) and glutathione (GSH) in cell culture supernatants were measured by ELISA. The apoptosis was analyzed by flow cytometry. The protein expression levels of Bcl-2 and Bax were determined by Western blot. The expression levels of long noncoding RNA ANRIL and microRNA-626 (miR-626) were detected by RT-qPCR. Dual-luciferase reporter assay was used to evaluate the relationship between ANRIL and miR-626. After ANRIL small interfering RNA was transfected into SK-N-SH cells, the effects of ANRIL expression knock-down on MPP⁺-induced SK-N-SH cell apoptosis, the protein expression levels of Bcl-2 and Bax, and the levels of MDA and GSH in cell culture supernatants were examined. RESULTS After treatment with MPP⁺, the apoptotic rate, Bax protein level and ANRIL expression in SK-N-SH cells were increased (P<0.05), and the Bcl-2 protein level and miR-626 expression were decreased (P<0.05). The level of MDA in cell culture supernatants was increased (P<0.05), and the level of GSH was decreased (P<0.05). After SN treatment or ANRIL expression knock-down, decreased apoptotic rate, Bax protein level and ANRIL expression (P<0.05), and increased Bcl-2 protein level and miR-626 expression in MPP⁺-induced SK-N-SH cells were observed (P<0.05). The level of MDA in the cell culture supernatants was decreased (P<0.05), and the level of GSH was increased (P<0.05). CONCLUSION SN attenuates MPP⁺-induced damage in SK-N-SH cells by regulating ANRIL/miR-626 signaling pathway.     

Geniposide attenuates cognitive dysfunction in sleep-deprived rats by inhibiting TLR4/NF-κB signaling pathway

AIM To investigate the effects of geniposide （Gen） on Toll like receptor 4/nuclear factor-κB （TLR4/NF-κB） signaling pathway and cognitive dysfunction in sleep deprived rats. METHODS Wistar rats （n=120） were randomly divided into normal control （NC） group， model （M） group， low-dose （5 g·kg^-1·d^-1） Gen （Gen-L） group， medium-dose （10 g·kg^-1·d^-1） Gen （Gen-M） group， high-dose （20 g·kg^-1·d^-1） Gen （Gen-H） group and Gen-H+LPS （0.4 mg·kg^-1·d^-1， tail vein injection） group. After 7 days of intervention， the sleep deprivation model of rats in M group， Gen-L， Gen-M， Gen-H and Gen-H+LPS group was established by improved small platform water environment. The escape latency of Morris water maze experiment and the behavior correct rate of Y maze experiment were measured. The serum levels of S100B and neuron-specific enolase （NSE）， and the levels of interleukin-1β （IL-1β）， IL-6 and tumor necrosis factor-α （TNF-α） in hippocampus were detected by ELISA. The mRNA levels of TLR4 and NF-κB p65 were detected by RT-qPCR， and the protein levels of TLR4 and NF-κB p65 were determined by Western blot. RESULTS Compared with NC group， the escape latency， the serum levels of S100B and NSE， the hippocampal levels of IL-1β， IL-6 and TNF-α， and the mRNA and protein expression of TLR4 and NF-κB p65 were increased significantly in M group （P<0.01）， and the behavior correct rate was decreased significantly （P<0.01）. Compared with M group， the escape latency， the hippocampal levels of IL-1β， IL-6 and TNF-α， and the expression of TLR4 and NF-κB p65 at mRNA and protein levels were decreased significantly in Gen-L， Gen-M and Gen-H groups （P<0.01）， and the behavior correct rate was increased in turn （P<0.01）. Compared with Gen-H group， the escape latency， the serum levels of S100B and NSE， the hippocampal levels of IL-1β， IL-6 and TNF-α， and the expression of TLR4 and NF-κB p65 at mRNA and protein levels were increased significantly in Gen-H+LPS group （P<0.01）， and the behavior correct rate was decreased significantly （P<0.01）. CONCLUSION Geniposide may inhibit the TLR4/NF-κB p65 signaling pathway to effectively improve cognitive function in sleep-deprived rats and reduce hippocampus inflammation.     

Experimental research on cardiac fibrosis induced by recombinant mouse interleukin-11 in mice

AIM To observe the effect of recombinant mouse interleukin-11 （rmIL-11）injected subcutaneously into mice on heart structure and function and to determine its pro-fibrotic effect. METHODS C57BL/6 mice were randomly divided into experimental group and control group.The mice in experimental group were injected subcutaneously with recombinant mouse IL-11 at the dose of 100 μg·kg^-1·d^-1 for 3 consecutive weeks, while the control group were given equal volume of normal saline in the same way. After the experiment was finished, the parameters of heart function were measured by echocardiography.The heart weight was weighed and the cardiac weight index (CWI) was calculated. HE staining and Masson's trichrome staining were performed to observe the pathological changes and the extent of myocardial fibrosis in mouse myocardia respectively, and the cardiac collagen volume fraction (CVF) was calculated. The expression levels of extracellular matrix proteins in the myocardial tissues of mice, including type Ⅰ collagen, type Ⅲ collagen and fibronectin, were determined by Western blot. RESULTS Left ventricular ejection fraction and left ventricular fraction shortening in experimental group were obviously lower than those in control group (P<0.01), however left ventricular end-diastolic diamension and left ventricular end systolic dimension were significantly higher than those in control group (P<0.05).Compared with control group, the CWI was increased (P<0.01), the myocardial arrangement was disorder, the necrosis of cardiac myocytes was increased, and excessive deposition of collagen was observed in the myocardial tissues in experimental group. Correspondingly, the CVF and protein levels of type Ⅰ collagen, type Ⅲ collagen and fibronectin in the left ventricle in experimental group were increased significantly (P<0.05). CONCLUSION Injection of rmIL-11 into the mice subcutaneously induces fibrogenesis in the heart, which implies that IL-11 is likely a novel pro-fibrotic factor.     

Effects of EGCG on GLUT2/G6PD/GS expression and blood glucose level in type 2 diabetic rats

AIM To investigate whether epigallocatechin gallate （EGCG） improves blood glucose in type 2 diabetic rats through glucose transporter 2 （GLUT2）-glucose-6-phosphate dehydrogenase （G6PD）-glycogen synthase （GS） pathway. METHODS Type 2 diabetes mellitus （T2DM） model was established in male Sprague-Dawley （SD） rats by feeding with high-fat diet and injection of streptozotocin （STZ）. The rats were divided into 5 groups （n=10）： control （Con） group， T2DM model （M） group， metformin （Met； 200 mg/kg， ig） group， T2DM+low-dose （50 mg/kg， ig） EGCG （EL） group， and T2DM+high-dose （100 mg/kg， ig） EGCG （EH） group. Diabetic rats were given drugs for 8 weeks. After 8 weeks of administration， the rats were killed， and the blood and liver tissues were collected. The levels of fasting blood glucose （FBG）， fasting serum insulin （FINS） and serum glycosylated hemoglobin were measured by biochemical tests. Liver glycogen were test by periodic acid-Schiff （PAS） staining. The mRNA expression of G6PD in the liver was detected by real-time PCR. The protein levels of GS and GLUT2 were determined by Western blot and immunohistochemistry. RESULTS T2DM rat model was established successfully. Compared with Con group， the levels of FBG， FINS and serum glycosylated hemoglobin in M group were increased significantly （P<0.05）， while the insulin sensitivity index （ISI）， the liver glycogen， the G6PD mRNA expression， and the protein levels of GS and GLUT2 were decreased significantly （P<0.05）. Compared with M group， the levels of FBG and serum glycosylated hemoglobin in Met group and EH group were decreased significantly （P<0.05）， while the ISI， the liver glycogen， the G6PD mRNA expression， and the protein levels of GS and GLUT2 were increased significantly （P<0.05）. CONCLUSION EGCG reduces the blood glucose level in T2DM rats， which may be related to the regulation of GLUT2-G6PD-GS signaling pathway.     

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.     

Protective effect of recombinant human serum albumin-thioredoxin fusion protein on mice with acute lung injury induced by influenza virus

AIM To investigate the protective effect of recombinant human serum albumin (HSA)-thioredox?in (Trx) fusion protein (HSA-Trx) on mice with acute lung injury (ALI) induced by influenza virus infection. METH?ODS: The recombinant HAS-Trx fusion protein was generated by Pichia pastoris expression system. ICR mice were used to establish the animal model of ALI induced by PR8 (H1N1) influenza virus, and the experimental mice were divided into healthy control group, ALI group, ALI+Trx group and ALI+HSA-Trx group, with 10 mice in each group. The bronchoalveolar lavage fluid (BALF) in each group was collected, the total number of cells and the number of alveolar neutrophils were determined, the protein concentration was measured by Coomassie brilliant blue solution method, and the interferon-γ (IFN-γ) content in BALF was detected by ELISA. The lung tissues were collected for hematoxylin and eosin staining. The inducible nitric oxide synthase (iNOS), 8-hydroxydeoxyguanosine (8-OHdG) and 3-nitrotyrosine (NO₂-Tyr) in lung tissues were detected by immunofluorescence method. Peroxide concentration in plasma was evaluated using a CR2000RC analyzer. RESULTS HSA-Trx treatment significantly reduced the total number of cells, neutrophils and total protein in BALF of ALI mice (P<0.05), and decreased the levels of 8-OHdG, NO₂-Tyr in lung tissue and peroxide in plasma (P<0.05). However, it has no significant inhibitory effect on iNOS and IFN-γ expression (P>0.05). CONCLUSION HSA-Trx inhibits inflammatory response and excessive production of nitric oxide in the lung, thus protecting influ?enza virus-induced ALI mice.     

Alleviating effect of exenatide on ectopic lipid accumulation in skeletal muscle of ob/ob mice is independent on reducing body weight

AIM To investigate the alleviating effect of exenatide （Exe）， a glucagon-like peptide-1 （GLP-1） receptor agonist， on the ectopic lipid accumulation in skeletal muscle of ob/ob mice and its mechanism. METHODS Eight-week-old male ob/ob mice and their wild-type （WT） littermates were randomly divided into 3 groups， ob/ob group， ob/ob+Exe group and WT group， and treated with Exe at 24 nmol/kg or the same volume of saline intraperitoneally once daily for 4 weeks. The body weight， fasting blood glucose （FBG） and fat content were measured after the 4-week treatment. The oil red O staining and the quantification of triglyceride （TG） were performed on the skeletal muscle. The serum levels of TG， total cholesterol and free fatty acid （FFA） were also measured by ELISA. The expression levels of AMP-activated protein kinase （AMPK） and lipid metabolism-related proteins were determined by Western blot. Mouse myoblast C2C12 cells were used as an in vitro model to further investigate the effects of Exe. RESULTS As compared with the ob/ob mice treated with saline， 4-week Exe treatment did not reduce body weight， FBG， food intake and fat content in ob/ob mice （P>0.05）. However， serum FFA was decreased （P<0.05）. Oil red O staining and the quantification of TG showed that 4-week Exe treatment significantly attenuated the ectopic lipid accumulation in the skeletal muscle of ob/ob mice （P<0.05）. The results of Western blot showed that the levels of phosphorylated AMPK （p-AMPK） and lipolysis-related proteins were up-regulated， while the lipid synthesis-related proteins were down-regulated by Exe （P<0.05）. Treatment with Exe alleviated the lipid accumulation in the C2C12 cells induced by sodium palmate （P<0.05）， and the effects of Exe on the levels of p-AMPK and lipid metabolism-related proteins in the C2C12 cells were consistent with those in the ob/ob mice （P<0.05）. Treatment with Exe also up-regulated the protein expression of glucose transporter 4 and improved the ability of glucose uptake in the C2C12 cells （P<0.05）. CONCLUSION Short-term Exe treatment attenuates the ectopic lipid accumulation in skeletal muscle of ob/ob mice by up-regulating lipolysis-related proteins and down-regulating lipid synthesis-related proteins， which is independent on body weight loss.     

NKT cells inhibit Ang II-induced phenotypic transformation of mouse vascular smooth muscle cells by down-regulating PDGFRβ

AIM To investigate the role of natural killer T (NKT) cells in the phenotypic transformation of vascular smooth muscle cells induced by hypertension in mice. METHODS The hypertension model in wild-type and CD1d gene knockout mice was established by continuous infusion of angiotensin II (Ang II) at a dose of 490 ng·kg^-1·min^-1 for 14 d, and the NKT cell specific agonist α-galactosylceramide (α-GC) was given at a dose of 100 μg/kg in wild-type mice. The blood pressure of the mice was monitored by non-invasive tail cuff method. The thickness of aortic wall was measured by HE staining, and the degree of aortic fibrosis was observed by Masson staining. The expression levels of α-smooth muscle actin (α-SMA), osteopontin (OPN) and platelet-derived growth factor receptor β (PDGFRβ) in aortic tissue were detected by Western blot. RESULTS Compared with control group, the blood pressure, the aortic wall thickness, the degree of aortic fibrosis, the secretory marker protein OPN expression and the PDGFRβ expression were all increased significantly after infusion of Ang II for 14 d (P<0.05), while the expression of contractile marker protein α-SMA was decreased (P<0.05). The above changes were aggravated after CD1d gene knockout (P<0.05), but were attenuated after administration of α-GC (P<0.05). CONCLUSION NKT cells reduces Ang II-induced phenotypic transformation of mouse vascular smooth muscle cells by reducing the expression of PDGFRβ, increasing the expression of contractile protein and decreasing the expression of secretory protein.