Boesenbergia pandurata Attenuates Diet-Induced Obesity by Activating AMP-Activated Protein Kinase and Regulating Lipid Metabolism

Obesity, a chronic metabolic disorder, is characterized by enlarged fat mass and dysregulation of lipid metabolism. The medicinal plant, Boesenbergia pandurata (Roxb.) Schltr., has been reported to possess anti-oxidative and anti-inflammatory properties; however, its anti-obesity activity is unexplored. The present study was conducted to determine whether B. pandurata extract (BPE), prepared from its rhizome parts, attenuated high-fat diet (HFD)-induced obesity in C57BL/6J mice. The molecular mechanism was investigated in 3T3-L1 adipocytes and HepG2 human hepatoma cells. BPE treatment decreased triglyceride accumulation in both 3T3-L1 adipocytes and HepG2 hepatocytes by activating AMP-activated protein kinase (AMPK) signaling and regulating the expression of lipid metabolism-related proteins. In the animal model, oral administration of BPE (200 mg/kg/day for 8 weeks) significantly reduced HFD-induced body weight gain without altering the amount of food intake. In addition, elevated serum levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides were suppressed by BPE administration. Fat pad masses were reduced in BPE-treated mice, as evidenced by reduced adipocyte size. Furthermore, BPE protected against the development of nonalcoholic fatty liver by decreasing hepatic triglyceride accumulation. BPE also activated AMPK signaling and altered the expression of lipid metabolism-related proteins in white adipose tissue and liver. Taken together, these findings indicate that BPE attenuates HFD-induced obesity by activating AMPK and regulating lipid metabolism, suggesting a potent anti-obesity agent.     

Effects of Bofu-Tsusho-San on Diabetes and Hyperlipidemia Associated with AMP-Activated Protein Kinase and Glucose Transporter 4 in High-Fat-Fed Mice

This study was undertaken to examine the effect and mechanism of Bofu-tsusho-san formula (BO) on hyperglycemia and hyperlipidemia and in mice fed with a high-fat (HF) diet. The C57BL/6J mice were received control/HF diet for 12 weeks, and oral administration of BO (at three doses) or rosiglitazone (Rosi) or vehicle for the last 4 weeks. Blood, skeletal muscle and tissues were examined by means of measuring glycaemia and dyslipidaemia-associated events. BO treatment effectively prevented HF diet-induced increases in the levels of triglyceride (TG), free fatty acid (FFA) and leptin (p < 0.01, p < 0.01, p < 0.01, respectively). BO treatment exhibited reduced both visceral fat mass and hepatic triacylglycerol content; moreover, BO treatment displayed significantly decreased both the average area of the cut of adipocytes and ballooning of hepatocytes. BO treatment exerted increased the protein contents of glucose transporter 4 (GLUT4) in skeletal muscle, and caused lowered blood glucose levels. BO treatment displayed increased levels of phosphorylated AMP-activated protein kinase (AMPK) in both skeletal muscle and liver tissue. Furthermore, BO reduced the hepatic expression of glucose-6-phosphatase (G6Pase) and phosphenolpyruvate carboxykinase (PEPCK) and glucose production. Therefore, it is possible that the activation of AMPK by BO leads to diminished gluconeogenesis in liver tissue. BO increased hepatic expressions of peroxisome proliferator-activated receptor α (PPARα), whereas down-regulating decreasing expressions of fatty acid synthesis, including sterol regulatory element binding protein 1c (SREBP1c) and fatty acid synthase (FAS), resulting in a decrease in circulating triglycerides. This study originally provides the evidence that amelioration of dyslipidemic and diabetic state by BO in HF-fed mice occurred by regulation of GLUT4, SREBP1c, FAS, PPARα, adiponectin and AMPK phosphorylation.     

Ghrelin Attenuates Liver Fibrosis through Regulation of TGF-β1 Expression and Autophagy

Ghrelin is a stomach-derived growth hormone secretagogue that promotes various physiological effects, including energy metabolism and amelioration of inflammation. The purpose of this study was to investigate the protective mechanism of ghrelin against liver fibrosis. Liver fibrosis was induced in C57BL/6 mice by intraperitoneal injection of CCl₄ (2.0 mL/kg of 10% CCl₄ v/v solution in peanut oil) two times per week for eight weeks. Ghrelin (10 μg/kg) was intraperitoneally injected two times per week for eight weeks. A second murine liver fibrosis model was induced by bile duct ligation (BDL) and concurrent ghrelin administration for four weeks. Hematoxylin eosin (H&E), and Masson’s trichrome were used to detect pathological changes to liver tissue. Western blotting was used to detect protein levels of transforming growth factor (TGF)-β1, phosphorylated Smad3 (p-Smad3), I-collage, α-smooth muscle actin (α-SMA), matrix metalloproteinases (MMPs) 2, tissue inhibitor of matrix metalloproteinases (TIMPs) 1, phosphorylated NF-κB (p-NF-κB), and microtubule-associated protein light chain 3 (LC3). In addition, qRT-PCR was used to detect mRNA levels of TGF-β1, I-collage, α-SMA, MMP2, TIMP1 and LC3, while levels of TGF-β1, p-Smad3, I-collage, α-SMA, and LC3 were detected immunohistochemically. Levels of aspartate aminotransferase and alanine aminotransferase were significantly decreased by ghrelin treatment. Ghrelin administration also significantly reduced the extent of pathological changes in both murine liver fibrosis models. Expression levels of I-collage and α-SMA in both models were clearly reduced by ghrelin administration. Furthermore, ghrelin treatment decreased protein expression of TGF-β1 and p-Smad3. The protein levels of NF-κB and LC3 were increased in the CCl₄- and BDL-treatment groups but were significantly reduced following ghrelin treatment. In addition, ghrelin inhibited extracellular matrix formation by decreasing NF-κB expression and maintaining the balance between MMP2 and TIMP1. Our results demonstrated that ghrelin attenuates liver fibrosis via inhibition of the TGF-β1/Smad3 and NF-κB signaling pathways, as well as autophagy suppression.     

Hepatocyte-Derived Igκ Exerts a Protective Effect against ConA-Induced Acute Liver Injury

Immunoglobulin (Igκ) has been reported to be expressed in sorted liver epithelial cells of μMT mice, and the sequence characteristics of hepatocyte-derived Igκ were different from those of classical B-cell-derived Igκ. However, the physiological function of hepatocyte-derived Igκ is still unclear. The expression of Igκ was firstly identified in primary hepatocytes and normal liver cell line (NCTC1469), and hepatocyte-derived Igκ expression was elevated and displayed unique localization in hepatocytes of concanavalin A (ConA)-induced hepatitis model. Moreover, Igκ knockout mice were more sensitive to ConA-induced hepatitis and had higher serum aspartate aminotransferase (AST) levels, more severe histological injury and a greater number of terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL)-positive cells as compared with littermate controls. Furthermore, knockdown of Igκ in primary hepatocytes and NCTC1469 cells led to accelerated activation of the mitochondrial death pathway and caspase-3 cleavage in vitro, which might be related to inhibition of NF-κB signaling pathway and activation of JNK via the cytoskeleton dynamics. Taken together, these results indicate that hepatocyte-derived Igκ mediates cellular resistance to ConA-induced liver injury by inhibiting activation of caspase-3 and the mitochondrial death pathway, suggesting that Igκ plays an important role in hepatocyte survival and exerts a protective effect against ConA-induced liver injury in mice.     

胆固醇在高脂高胆固醇诱导非酒精性脂肪性肝炎发生发展过程中的动态作用

目的探讨胆固醇在高脂高胆固醇诱导的非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)发生发展过程中的动态作用。方法将SD大鼠随机分为CON组(正常饮食)、HFC0组(20%脂肪)、HFC1组(20%脂肪+1%胆固醇)、HFC2组(20%脂肪+2%胆固醇)及HFC5组(20%脂肪+5%胆固醇)。饲喂第4、6、8及12周末,采血并取肝脏组织;采用油酸(oleic acid,OA)及OA+低密度脂蛋白-胆固醇(low-density lipoprotein-cholesterol,LDL-C)诱导人肝脏正常细胞(HL-7702)5 d后,构建NASH模型,同时以RPMI1640培养基(含10%FBS)为对照组。分别检测大鼠血浆及HL-7702细胞培养液中丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转氨酶(AST)的含量,大鼠肝脏组织及HL-7702细胞中总胆固醇(total cholesterol,TC)及甘油三酯(triglyceride,TG)的含量;HE及Masson染色观察肝脏组织病理改变;油红O及菲律宾菌素染色观察HL-7702细胞内脂滴及胆固醇含量;Western blot法检测活性n-固醇调节元件结合蛋白-2(n-sterol regulatory element binding protein 2,n-SREBP-2)、低密度脂蛋白受体(low-density lipoproteins receptors,LDLR)及3-羟基3-甲基戊二酰辅酶A还原酶(3-hydroxy-3-methylglutaryl-CoA reductase,HMGCR)的蛋白表达水平。结果动物水平:12周末,与CON组比较,HFC2组、HFC5组血浆中ALT、AST及肝脏组织中TC、TG含量均显著升高(P均<0.05),肝细胞脂肪变性、气球样变性及纤维化病变明显,HFC2组、HFC5组大鼠NASH诱导成功;经Western blot分析,4、6及8周末,HFC2组、HFC5组较CON组LDLR蛋白表达水平均显著升高(P均<0.05),12周末,HFC5组较CON组LDLR蛋白表达水平显著降低(P<0.05);4、6及8周末,各组n-SREBP-2蛋白表达水平与CON组比较差异均无统计学意义(P均>0.05),12周末,HFC2组、HFC5组较CON组n-SREBP-2蛋白表达水平均显著升高(P均<0.05);4、6及12周末各组HMGCR蛋白表达水平与CON组比较差异均无统计学意义(P均>0.05),8周末,HFC5组较CON组HMGCR蛋白表达水平显著降低(P<0.05)。细胞水平:OA+LDL-C组较对照组及OA组细胞内胆固醇含量、n-SREBP-2及HMGCR蛋白表达水平均显著升高(P均<0.05);OA组及OA+LDL-C组较对照组LDLR蛋白表达水平均显著降低(P均<0.05)。结论胆固醇摄入量和摄入时间的长短与NASH肝损伤呈正相关;胆固醇可诱导肝细胞高表达LDLR,促使胆固醇进入肝脏增加,抑制HMGCR调控的内源性胆固醇合成;随着肝内胆固醇堆积增多,肝细胞LDLR表达减少,使肝内胆固醇相对不足,反馈性调节n-SREBP-2及HMGCR表达升高,打破肝脏胆固醇代谢稳态,促进了NASH的发生发展。     

A pH and Redox Dual Responsive 4-Arm Poly(ethylene glycol)-block-poly(disulfide histamine) Copolymer for Non-Viral Gene Transfection in Vitro and in Vivo

A novel 4-arm poly(ethylene glycol)-b-poly(disulfide histamine) copolymer was synthesized by Michael addition reaction of poly(ethylene glycol) (PEG) vinyl sulfone and amine-capped poly(disulfide histamine) oligomer, being denoted as 4-arm PEG-SSPHIS. This copolymer was able to condense DNA into nanoscale polyplexes (<200 nm in average diameter) with almost neutral surface charge (+(5–10) mV). Besides, these polyplexes were colloidal stable within 4 h in HEPES buffer saline at pH 7.4 (physiological environment), but rapidly dissociated to liberate DNA in the presence of 10 mM glutathione (intracellular reducing environment). The polyplexes also revealed pH-responsive surface charges which markedly increased with reducing pH values from 7.4–6.3 (tumor microenvironment). In vitro transfection experiments showed that polyplexes of 4-arm PEG-SSPHIS were capable of exerting enhanced transfection efficacy in MCF-7 and HepG2 cancer cells under acidic conditions (pH 6.3–7.0). Moreover, intravenous administration of the polyplexes to nude mice bearing HepG2-tumor yielded high transgene expression largely in tumor rather other normal organs. Importantly, this copolymer and its polyplexes had low cytotoxicity against the cells in vitro and caused no death of the mice. The results of this study indicate that 4-arm PEG-SSPHIS has high potential as a dual responsive gene delivery vector for cancer gene therapy.     

Differential Effects of High-Fish Oil and High-Lard Diets on Cells and Cytokines Involved in the Inflammatory Process in Rat Insulin-Sensitive Tissues

Dietary fat sources may differentially affect the development of inflammation in insulin-sensitive tissues during chronic overfeeding. Considering the anti-inflammatory properties of ω-3 fatty acids, this study aimed to compare the effects of chronic high-fish oil and high-lard diets on obesity-related inflammation by evaluating serum and tissue adipokine levels and histological features in insulin-sensitive tissues (white adipose tissue, skeletal muscle and liver). As expected, a high-lard diet induced systemic and peripheral inflammation and insulin resistance. Conversely, compared with a high-lard diet, a high-fish oil diet resulted in a lower degree of systemic inflammation and insulin resistance that were associated with a lower adipocyte diameter as well as lower immunoreactivity for transforming growth factor β 1 (TGFβ1) in white adipose tissue. A high-fish oil diet also resulted in a lower ectopic lipid depot, inflammation degree and insulin resistance in the skeletal muscle and liver. Moreover, a high-fish oil diet attenuated hepatic stellate cell activation and fibrogenesis in the liver, as indicated by the smooth muscle α-actin (α-SMA) and TGFβ1 levels. The replacement of lard (saturated fatty acids) with fish oil (ω-3 fatty acids) in chronic high-fat feeding attenuated the development of systemic and tissue inflammation.     

Morphology, thermal stability and rheology of poly(propylene carbonate)/organoclay nanocomposites with different pillaring agents

Unpillared montmorillonite PGV and five organoclays (Nanocor's Nanomer I.44P, I.24TL and I.34TCN and Southern Clay Product's C25A and C30B) were high shear melt-blended (2.5 wt%) into poly(propylene carbonate) (PPC). Solubility parameters of the clay pillaring agents versus that of PPC were used to predict clay/PPC miscibilities and these were compared to XRD and TEM nanoclay dispersion measurements. Clays I.34TCN and C30B, with the highest predicted pillaring agent/PPC miscibilites, had partially exfoliated morphologies. Clays I.24TL, C25A and I.44P, with pillaring agents predicted to be less PPC miscible, were less highly nanodispersed. Quaternary ammonium pillars with two 2-hydroxyethyl groups promoted the best nanodispersion in PPC. 12-Aminododecanoic acid (in I.24TL) promoted the intercalation. Dimethyl dialkyl quaternary ammoniums (in I.44P and C25A) were less effective. Organoclay dispersion improved the thermal stability. The PPC/I.24TL nanocomposite, with the most stable 12-aminododecanoic acid pillar, was the most thermally stable (PPC/I.34TCN and PPC/C30B were the second and third). The nanocomposites exhibited narrower linear viscoelastic zones than PPC and solid-like behaviors in these linear zones.     

Glycosyltransferase GLT8D2 Positively Regulates ApoB100 Protein Expression in Hepatocytes

Non-alcoholic fatty liver disease (NAFLD) is characterized by triglyceride (TG) accumulation in hepatocytes. Very low density lipoprotein (VLDL) is a major secretory product of the liver that transports endogenously synthesized TG. Disrupted VLDL secretion may contribute to the accumulation of TG in hepatocytes. ApoB100 (apolipoprotein B100) is a glycoprotein and an essential protein component of VLDL. Its glycosylation may affect VLDL assembly and secretion. However, which glycosyltransferase catalyzes apoB100 glycosylation is unknown. In this study, we cloned the GLT8D2 (glycosyltransferase 8 domain containing 2) gene from HepG2 cells and generated a series of plasmids for in vitro studies of its molecular functions. We discovered that GLT8D2 was localized in the ER, interacted with apoB100, and positively regulated the levels of apoB100 protein in HepG2 cells. Based on these results, we propose that GLT8D2 is a glycosyltransferase of apoB100 that regulates apoB100 levels in hepatocytes.     

Enhanced Antitumor Effects of Adenoviral-Mediated siRNA against GRP78 Gene on Adenosine-Induced Apoptosis in Human Hepatoma HepG2 Cells

Our previous studies show that adenosine-induced apoptosis is involved in endoplasmic reticulum stress in HepG2 cells. In this study, we have investigated whether knockdown of GRP78 by short hairpin RNA (shRNA) increases the cytotoxic effects of adenosine in HepG2 cells. The adenovirus vector-delivered shRNA targeting GRP78 (Ad-shGRP78) was constructed and transfected into HepG2 cells. RT-PCR assay was used to determine RNA interference efficiency. Effects of knockdown of GRP78 on adenosine-induced cell viabilities, cell-cycle distribution and apoptosis, as well as relative protein expressions were determined by flow cytometry and/or Western blot analysis. The intracellular Ca²⁺ concentration was detected by laser scanning confocal microscope. Mitochondrial membrane potential (ΔΨm) was measured by a fluorospectrophotometer. The results revealed that GRP78 mRNA was significantly downregulated by Ad-shGRP78 transfection. Knockdown of GRP78 enhanced HepG2 cell sensitivity to adenosine by modulating G0/G1 arrest and stimulating Bax, Bak, m-calpain, caspase-4 and CHOP protein levels. Knockdown of GRP78 worsened cytosolic Ca²⁺ overload and ΔΨm loss. Knockdown of caspase-4 by shRNA decreased caspase-3 mRNA expression and cell apoptosis. These findings indicate that GRP 78 plays a protective role in ER stress-induced apoptosis and show that the combination of chemotherapy drug and RNA interference adenoviruses provides a new treatment strategy against malignant tumors.     

IL-33 Enhances IFNγ and TNFα Production by Human MAIT Cells: A New Pro-Th1 Effect of IL-33

Mucosal-associated invariant T (MAIT) cells represent a distinct T cell population restricted by the MHC-class-I-related molecule, MR1, which recognizes microbial-derived vitamin B2 (riboflavin) metabolites. Their abundance in humans, together with their ability to promptly produce distinct cytokines including interferon γ (IFNγ) and tumor necrosis factor α (TNFα), are consistent with regulatory functions in innate as well as adaptive immunity. Here, we tested whether the alarmin interleukin 33 (IL-33), which is secreted following inflammation or cell damage, could activate human MAIT cells. We found that MAIT cells stimulated with IL-33 produced high levels of IFNγ, TNFα and Granzyme B (GrzB). The action of IL-33 required IL-12 but was independent of T cell receptor (TCR) cross-linking. MAIT cells expressed the IL-33 receptor ST2 (suppression of tumorigenicity 2) and upregulated Tbet (T-box expressed in T cells) in response to IL-12 or IL-33. Electronically sorted MAIT cells also upregulated the expression of CCL3 (Chemokine C-C motif ligand 3), CD40L (CD40 Ligand), CSF-1 (Colony Stimulating Factor 1), LTA (Lymphotoxin-alpha) and IL-2RA (IL-2 receptor alpha chain) mRNAs in response to IL-33 plus IL-12. In conclusion, IL-33 combined with IL-12 can directly target MAIT cells to induce their activation and cytokine production. This novel mechanism of IL-33 activation provides insight into the mode of action by which human MAIT cells can promote inflammatory responses in a TCR-independent manner.     

CXCL10 Decreases GP73 Expression in Hepatoma Cells at the Early Stage of Hepatitis C Virus (HCV) Infection

Golgi protein 73 (GP73), which is up-regulated in hepatocellular carcinoma (HCC), has recently been identified as a novel serum marker for HCC diagnosis. Several reports also noted the increased levels of GP73 expression in chronic liver disease in patients with acute hepatitis of various etiologies, chronic Hepatitis C virus (HCV) infection and alcoholic liver disease. The molecular mechanisms of GP73 expression in HCV related liver disease still need to be determined. In this study, we aimed to evaluate the effect of HCV infection on GP73 expression. GP73 was highly expressed in Huh7, Hep3B, 293T and HUVEC cells, and was low-expressed in HepG2 cells. HCV infection led to down-regulation of GP73 in Huh7 and HepG2/CD81 cells at the early stage of infection. CXCL10 decreased GP73 expression in Huh7 and HepG2 cells. Up-regulation of GP73 was noted in hepatocytes with cytopathic effect at advanced stage of HCV infection, and further research is needed to determine the unknown factors affecting GP73 expression. In conclusion, our study provided additional evidence for the roles of GP73 in liver disease.     

解偶联蛋白-2在软脂酸诱导的HepG2细胞胰岛素抵抗中的作用及其与核转录因子-κB的关系

目的探讨解偶联蛋白-2(Uncoupling protein-2,UCP-2)在软脂酸诱导的HepG2细胞胰岛素抵抗(Insulin-resistance,IR)中的作用及其与核转录因子-κB(Nuclearfactor-κB,NF-κB)的关系。方法将HepG2细胞分为正常对照组、软脂酸组(加0.25mmol/L软脂酸)、高胰岛素组(加100nmol/L胰岛素)、软脂酸+京尼平组(加0.25mmol/L软脂酸和10μmol/L京尼平),培养24h后,再用100nmol/L胰岛素刺激,分别于12h后测定培养液中葡萄糖、MDA、SOD、ALT、AST、GGT、TG的浓度;油红O染色法观察细胞的脂变情况;流式细胞术检测线粒体膜电位改变;30min后采用半定量RT-PCR及Westernblot法检测细胞IRS-2、UCP-2及NF-κB的表达水平。结果胰岛素作用12h后,细胞培养液中葡萄糖含量软脂酸组与高胰岛素组比较,差异无统计学意义(P>0.05)。培养液中葡萄糖含量、ALT、AST、MDA、GGT、TG的含量及UCP-2和NF-κB的表达水平,软脂酸组均较正常对照组和软脂酸+京尼平组显著升高(P<0.05),软脂酸+京尼平组与正常对照组比较差异无统计学意义(P>0.05)。线粒体膜电位、SOD和IRS-2的水平,软脂酸组显著低于正常对照组和软脂酸+京尼平组(P<0.05),软脂酸+京尼平组与正常对照组比较差异无统计学意义(P>0.05)。结论 UCP-2在软脂酸诱导的肝脏胰岛素抵抗中起着重要作用,其机制可能与NF-κB有关。     

GCase and LIMP2 Abnormalities in the Liver of Niemann Pick Type C Mice

The lysosomal storage disease Niemann–Pick type C (NPC) is caused by impaired cholesterol efflux from lysosomes, which is accompanied by secondary lysosomal accumulation of sphingomyelin and glucosylceramide (GlcCer). Similar to Gaucher disease (GD), patients deficient in glucocerebrosidase (GCase) degrading GlcCer, NPC patients show an elevated glucosylsphingosine and glucosylated cholesterol. In livers of mice lacking the lysosomal cholesterol efflux transporter NPC1, we investigated the expression of established biomarkers of lipid-laden macrophages of GD patients, their GCase status, and content on the cytosol facing glucosylceramidase GBA2 and lysosomal integral membrane protein type B (LIMP2), a transporter of newly formed GCase to lysosomes. Livers of 80-week-old Npc1^−/− mice showed a partially reduced GCase protein and enzymatic activity. In contrast, GBA2 levels tended to be reciprocally increased with the GCase deficiency. In Npc1^−/− liver, increased expression of lysosomal enzymes (cathepsin D, acid ceramidase) was observed as well as increased markers of lipid-stressed macrophages (GPNMB and galectin-3). Immunohistochemistry showed that the latter markers are expressed by lipid laden Kupffer cells. Earlier reported increase of LIMP2 in Npc1^−/− liver was confirmed. Unexpectedly, immunohistochemistry showed that LIMP2 is particularly overexpressed in the hepatocytes of the Npc1^−/− liver. LIMP2 in these hepatocytes seems not to only localize to (endo)lysosomes. The recent recognition that LIMP2 harbors a cholesterol channel prompts the speculation that LIMP2 in Npc1^−/− hepatocytes might mediate export of cholesterol into the bile and thus protects the hepatocytes.     

福辛普利对非酒精性脂肪性肝炎大鼠肝组织ACE和ACE2基因mRNA转录水平的影响

目的探讨福辛普利对高脂饮食诱导的非酒精性脂肪性肝炎(Nonalcoholic steatohepatitis,NASH)大鼠肝组织ACE和ACE2基因mRNA转录水平的影响,为阐明NASH的发病机制及探索新的治疗策略提供实验依据。方法将40只雄性SD大鼠用普通饲料喂养1周后,随机分为4组:正常对照组(NC组,普通饲料+生理盐水1 ml灌胃)、高脂组(HC组,高脂饲料+生理盐水1 ml灌胃)、药物对照组[NF组,正常饲料+福辛普利3.6 mg/(kg.d)灌胃]和药物干预组[HF组,高脂饲料+福辛普利3.6 mg/(kg.d)灌胃],每组10只。给药24周后,分析各组大鼠肝组织病理学变化,检测各组大鼠血清中谷丙转氨酶(Alanine aminotransferase,ALT)、碱性磷酸酶(Alkaline phosphatase,ALP)、甘油三酯(Triglycerides,TG)、低密度脂蛋白(Low-density lipoprotein,LDL)、转化生长因子-β(Transforming growth factor-β,TGF-β)、血管紧张素转换酶(Angiotensin-convert ingenzyme,ACE)、ACE2、血管紧张素Ⅱ(AngiotensinⅡ,AngⅡ)和Ang(-1-7)的水平;RT-PCR检测各组大鼠肝组织ACE和ACE2基因mRNA的转录水平;Western blot检测各组大鼠肝组织Ⅰ型胶原蛋白(CollagenⅠ)的表达水平。结果给药24周后,HF组非酒精脂肪性肝病活动度评分和肝纤维化程度与HC组相比,均明显下降(P<0.001);HF组血清中ALT、ALP、TG、LDL、TGF-β、ACE和AngⅡ的水平均明显低于HC组(P<0.05),而ACE2和Ang(-1-7)的水平均明显高于HC组(P<0.05);福辛普利可显著降低肝组织ACE基因mRNA的转录水平(P<0.001)和CollagenⅠ蛋白的表达水平(P<0.01),升高ACE2基因mRNA的转录水平(P<0.01)。结论福辛普利可能通过下调ACE和上调ACE2的生成和表达,从而降低AngⅡ和升高Ang(-1-7)的生成,具有改善NASH和抗肝纤维化作用。本实验为阐明NASH的发病机制及探索新的治疗策略提供了实验依据。     

Mesenchymal Stromal Cell Therapy in Novel Porcine Model of Diffuse Liver Damage Induced by Repeated Biliary Obstruction

In liver surgery, biliary obstruction can lead to secondary biliary cirrhosis, a life-threatening disease with liver transplantation as the only curative treatment option. Mesenchymal stromal cells (MSC) have been shown to improve liver function in both acute and chronic liver disease models. This study evaluated the effect of allogenic MSC transplantation in a large animal model of repeated biliary obstruction followed by partial hepatectomy. MSC transplantation supported the growth of regenerated liver tissue after 14 days (MSC group, n = 10: from 1087 ± 108 (0 h) to 1243 ± 92 mL (14 days); control group, n = 11: from 1080 ± 95 (0 h) to 1100 ± 105 mL (14 days), p = 0.016), with a lower volume fraction of hepatocytes in regenerated liver tissue compared to resected liver tissue (59.5 ± 10.2% vs. 70.2 ± 5.6%, p < 0.05). Volume fraction of connective tissue, blood vessels and bile vessels in regenerated liver tissue, serum levels of liver enzymes (AST, ALT, ALP and GGT) and liver metabolites (albumin, bilirubin, urea and creatinine), as well as plasma levels of IL-6, IL-8, TNF-α and TGF-β, were not affected by MSC transplantation. In our novel, large animal (pig) model of repeated biliary obstruction followed by partial hepatectomy, MSC transplantation promoted growth of liver tissue without any effect on liver function. This study underscores the importance of translating results between small and large animal models as well as the careful translation of results from animal model into human medicine.     

Evaluating the Effects of Subnormothermic Perfusion with AP39 in a Novel Blood-Free Model of Ex Vivo Kidney Preservation and Reperfusion

The use of blood for normothermic and subnormothermic kidney preservation hinders the translation of these approaches and promising therapeutics. This study evaluates whether adding hydrogen sulfide donor AP39 to Hemopure, a blood substitute, during subnormothermic perfusion improves kidney outcomes. After 30 min of renal pedicle clamping, porcine kidneys were treated to 4 h of static cold storage (SCS-4 °C) or subnormothermic perfusion at 21 °C with Hemopure (H-21 °C), Hemopure + 200 nM AP39 (H200nM-21 °C) or Hemopure + 1 µM AP39 (H1µM-21 °C). Then, kidneys were reperfused with Hemopure at 37 °C for 4 h with metabolic support. Perfusate composition, tissue oxygenation, urinalysis and histopathology were analyzed. During preservation, the H200nM-21 °C group exhibited significantly higher urine output than the other groups and significantly higher tissue oxygenation than the H1µM-21 °C group at 1 h and 2h. During reperfusion, the H200nM-21 °C group exhibited significantly higher urine output and lower urine protein than the other groups. Additionally, the H200nM-21 °C group exhibited higher perfusate pO₂ levels than the other groups and significantly lower apoptotic injury than the H-21 °C and the H1µM-21 °C groups. Thus, subnormothermic perfusion at 21 °C with Hemopure + 200 nM AP39 improves renal outcomes. Additionally, our novel blood-free model of ex vivo kidney preservation and reperfusion could be useful for studying other therapeutics.     

O-1602 Promotes Hepatic Steatosis through GPR55 and PI3 Kinase/Akt/SREBP-1c Signaling in Mice

Non-alcoholic fatty liver disease is recognized as the leading cause of chronic liver disease. Overnutrition and obesity are associated with hepatic steatosis. G protein-coupled receptor 55 (GPR55) has not been extensively studied in hepatic steatosis, although its endogenous ligands have been implicated in liver disease progression. Therefore, the functions of GPR55 were investigated in Hep3B human hepatoma cells and mice fed high-fat diets. O-1602, the most potent agonist of GPR55, induced lipid accumulation in hepatocytes, which was reversed by treatment with CID16020046, an antagonist of GPR55. O-1602 also induced intracellular calcium rise in Hep3B cells in a GPR55-independent manner. O-1602-induced lipid accumulation was dependent on the PI3 kinase/Akt/SREBP-1c signaling cascade. Furthermore, we found increased levels of lysophosphatidylinositol species of 16:0, 18:0, 18:1, 18:2, 20:1, and 20:2 in the livers of mice fed a high-fat diet for 4 weeks. One-week treatment with CID16020046 suppressed high-fat diet-induced lipid accumulation and O-1602-induced increase of serum triglyceride levels in vivo. Therefore, the present data suggest the pro-steatotic function of GPR55 signaling in hepatocytes and provide a potential therapeutic target for non-alcoholic fatty liver disease.