滴鼻大肠杆菌对高脂诱导肥胖小鼠糖脂代谢的影响

目的:探讨滴鼻大肠杆菌对高脂诱导肥胖小鼠糖脂代谢的影响。方法:选取48只高脂诱导的肥胖小鼠作为肥胖组,48只非肥胖小鼠作为对照组,滴鼻40μL含4×10~9 CFUs大肠杆菌菌液,于感染前及感染后1、2、3、4 d检测2组小鼠血清糖脂代谢相关指标及肝脏脂质沉积情况。结果:与感染前比较,肥胖小鼠体质量、附睾脂肪组织质量及指数在感染后1~4d显著降低(P0.05);血清空腹血糖(FBG)、空腹胰岛素(FINS)水平以及胰岛素抵抗指数(HOMA-IR)在2~4d显著升高(P0.05);血清游离脂肪酸(FFA)、甘油三酯(TG)和极低密度脂蛋白(VLDL)水平在1~4 d显著升高总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDLC)水平在1~3d显著降低(P0.05);肝脏质量、指数及TG含量在1~4d显著升高(P0.05),肝细胞脂滴蓄积在感染后2和4d明显增多。与对照组比较肥胖组小鼠血清TC、LDL-C和HDL-C水平在感染后显著降低,其余指标均明显升高(P0.05)。结论:滴鼻大肠杆菌可加剧肥胖小鼠糖脂代谢紊乱程度,促进其胰岛素抵抗及肝脏脂肪化的发生、发展。     

Elevated systemic monocyte chemoattractrant protein-1 in hepatic steatosis without significant hepatic inflammation

Non-alcoholic fatty liver disease (NAFLD) is strongly associated with obesity and the metabolic syndrome. It encompasses a clinico-pathologic spectrum of conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). The latter develops upon pro-inflammatory cell infiltration and is widely considered as the first relevant pathophysiological step in NAFLD-progression. The chemokine monocyte chemoattractant protein 1 (MCP-1) plays an important role in the progression of hepatic inflammation and fibrosis, and both increased hepatic expression and circulating serum levels have been described in NASH. Here, we aimed to investigate MCP-1 expression in simple hepatic steatosis. Upon feeding a high-fat diet mice developed hepatic steatosis in the absence of significant hepatic inflammation, but elevated hepatic MCP-1 expression compared to control mice fed a standard chow. Interestingly, high-fat diet fed mice had significantly higher MCP-1 serum levels, and MCP-1 mRNA expression was significantly increased in visceral adipose tissue. Furthermore, MCP-1 serum levels were also elevated in patients with ultrasound-diagnosed NAFLD and correlated with the body-mass index and fasting glucose. In conclusion, our data indicate both the liver and adipose tissue as cellular sources of elevated circulating MCP-1 levels already in the early phase of hepatic steatosis. Since MCP-1 derived from visceral adipose tissue reaches the liver via portal circulation at high concentrations it may significantly contribute to the progression of simple steatosis to NASH.     

Protease-activated receptor 1 and hematopoietic cell tissue factor are required for hepatic steatosis in mice fed a Western diet

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of obesity and metabolic syndrome and contributes to increased risk of cardiovascular disease and liver-related morbidity and mortality. Indeed, obese patients with metabolic syndrome generate greater amounts of thrombin, an indication of coagulation cascade activation. However, the role of the coagulation cascade in Western diet-induced NAFLD has not been investigated. Using an established mouse model of Western diet-induced NAFLD, we tested whether the thrombin receptor protease-activated receptor 1 (PAR-1) and hematopoietic cell-derived tissue factor (TF) contribute to hepatic steatosis. In association with hepatic steatosis, plasma thrombin-antithrombin levels and hepatic fibrin deposition increased significantly in C57Bl/6J mice fed a Western diet for 3 months. PAR-1 deficiency reduced hepatic inflammation, particularly monocyte chemoattractant protein-1 expression and macrophage accumulation. In addition, PAR-1 deficiency was associated with reduced steatosis in mice fed a Western diet, including reduced liver triglyceride accumulation and CD36 expression. Similar to PAR-1 deficiency, hematopoietic cell TF deficiency was associated with reduced inflammation and reduced steatosis in livers of low-density lipoprotein receptor-deficient mice fed a Western diet. Moreover, hematopoietic cell TF deficiency reduced hepatic fibrin deposition. These studies indicate that PAR-1 and hematopoietic cell TF are required for liver inflammation and steatosis in mice fed a Western diet.     

Differential induction of genes in liver and brown adipose tissue regulated by peroxisome proliferator-activated receptor-alpha during fasting and cold exposure in acyl-CoA dehydrogenase-deficient mice

Mice deficient for either long-chain acyl-CoA dehydrogenase (LCAD-/-) or very-long-chain acyl-CoA dehydrogenase (VLCAD-/-) develop hepatic steatosis upon fasting, due to disrupted mitochondrial fatty acid oxidation. Moreover, neither mouse model can maintain core body temperature when exposed to cold. We investigated the effects of fasting and cold exposure on gene expression in these mice. Non-fasted LCAD-/- mice showed gene expression changes indicative of fatty liver, including elevated mRNA levels for peroxisome proliferator-activated receptor-gamma (PPARgamma) and genes involved in lipogenesis. In LCAD-/- and VLCAD-/- mice challenged with fasting and cold exposure, expression of fatty acid oxidation genes was elevated in liver, consistent with increased PPARalpha activity. This effect was not seen in brown adipose tissue, suggesting that expression of these genes may be regulated differently than in liver. The effect of acute cold exposure on expression of fatty acid oxidation genes was measured in peroxisome proliferator-activated receptor (PPAR)-alpha-deficient mice (PPARalpha-/-) and controls. In PPARalpha-/- mice, basal expression of the acyl-CoA dehydrogenases was reduced in liver but was not altered in brown adipose tissue. While cold altered the expression of PPARgamma, sterol-regulatory element binding protein-1 (SREBP-1), ATP citrate lyase, and the uncoupling proteins in brown adipose tissue from both PPARalpha-/- and control mice, fatty acid oxidation genes were unaffected. Thus, while fatty acid oxidation appears critical for non-shivering thermogenesis, expression of the acyl-CoA dehydrogenases is not influenced by cold exposure. Moreover, mitochondrial fatty acid oxidation genes are not regulated by PPARalpha in brown adipose tissue as they are in liver.     

姜黄素激活自噬干预非酒精性脂肪肝病模型大鼠氧化应激及炎症反应

背景:自噬、氧化应激及炎症反应在非酒精性脂肪肝病中扮演重要角色,姜黄素具有调节自噬、氧化应激及炎症反应等生物活性。目的:探讨姜黄素对非酒精性脂肪肝病大鼠模型保护作用以及机制研究。方法:高糖高脂饮食8周建立非酒精性脂肪肝病大鼠模型,将40只SD大鼠分成对照组、模型组、姜黄素治疗组、姜黄素+3-甲基腺嘌呤组。在第8周末开始干预,对照组和模型组给予PBS灌胃,姜黄素组给予姜黄素500 mg/(kg·d)灌胃,姜黄素+3-甲基腺嘌呤组给予姜黄素500 mg/(kg·d)灌胃及2 mg/(kg·d)自噬抑制剂3-甲基腺嘌呤腹腔注射,干预8周。检测大鼠血清丙氨酸氨基转移酶、天冬氨酸氨基转移酶及总三酰甘油、总胆固醇、空腹血糖浓度;油红O染色观察各组大鼠肝内细胞脂滴分布,透射电镜观察肝细胞线粒体超微结构;采用硫代巴比妥酸法及黄嘌呤氧化酶法测定丙二醛及超氧化物歧化酶活性;Western blot检测自噬及炎症相关蛋白P62、LC3Ⅱ、Beclin-1、NF-κB的表达。实验方案经武汉大学人民医院动物实验伦理委员会批准(批准号2018-541)。结果与结论:①大鼠血清丙氨酸氨基转移酶、天冬氨酸氨基转移酶及总三酰甘油、总胆固醇水平:模型组均高于对照组(P<0.05),姜黄素治疗组显著低于模型组(P<0.05),姜黄素+3-甲基腺嘌呤组高于姜黄素治疗组但低于模型组(均<0.05);②细胞脂质沉积:模型组明显多于对照组;姜黄素治疗组明显少于模型组,姜黄素+3-甲基腺嘌呤组明显高于姜黄素治疗组但低于模型组;③透射电镜观察发现对照组未见明显线粒体损伤,模型组线粒体明显水肿,嵴断裂或消失等,姜黄素可显著缓解线粒体损伤,姜黄素+3-甲基腺嘌呤组对线粒体损失在模型组及姜黄素之间;④肝组织内超氧化物歧化酶水平:模型组显著低于对照组,姜黄素治疗组显著高于模型组,姜黄素+3-甲基腺嘌呤组显著低于姜黄素治疗组但高于模型组;⑤肝组织丙二醛水平:模型组显著高于对照组,姜黄素治疗组显著低于模型组,姜黄素+3-甲基腺嘌呤组显著高于姜黄素治疗组但低于模型组;⑥Western blot检测:与对照组相比,模型组肝组织P62、NF-κB蛋白表达均增加,而Beclin-1、LC3Ⅱ/LC3Ⅰ均降低(P均<0.05),经姜黄素治疗后P62、NF-κB蛋白表达均降低,而Beclin-1、LC3Ⅱ/LC3Ⅰ增加;姜黄素+3-甲基腺嘌呤组P62、NF-κB蛋白表达均低于模型组但高于姜黄素组,而Beclin-1、LC3Ⅱ/LC3Ⅰ高于模型组但低于姜黄素组,差异均有显著性意义(P均<0.05);⑦结果说明,姜黄素通过激活自噬调节炎症反应及氧化应激而改善非酒精脂肪肝病大鼠模型脂肪变性。     

Increased mitochondrial biogenesis in muscle improves aging phenotypes in the mtDNA mutator mouse

Aging is an intricate process that increases susceptibility to sarcopenia and cardiovascular diseases. The accumulation of mitochondrial DNA (mtDNA) mutations is believed to contribute to mitochondrial dysfunction, potentially shortening lifespan. The mtDNA mutator mouse, a mouse model with a proofreading-deficient mtDNA polymerase γ, was shown to develop a premature aging phenotype, including sarcopenia, cardiomyopathy and decreased lifespan. This phenotype was associated with an accumulation of mtDNA mutations and mitochondrial dysfunction. We found that increased expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), a crucial regulator of mitochondrial biogenesis and function, in the muscle of mutator mice increased mitochondrial biogenesis and function and also improved the skeletal muscle and heart phenotypes of the mice. Deep sequencing analysis of their mtDNA showed that the increased mitochondrial biogenesis did not reduce the accumulation of mtDNA mutations but rather caused a small increase. These results indicate that increased muscle PGC-1α expression is able to improve some premature aging phenotypes in the mutator mice without reverting the accumulation of mtDNA mutations.     

紫薯花色苷提取物对ApoE~(-/-)小鼠动脉粥样硬化和高脂血症的作用

目的:研究紫薯花色苷提取物对Apo E-/-小鼠动脉粥样硬化和高脂血症的作用。方法:将8周龄雄性ApoE~(-/-)小鼠随机分为对照组、高脂饮食组、花色苷低剂量组、花色苷高剂量组和立普妥组,共5组(n=10),除对照组小鼠饲喂普通饲料外,其它4组在饲喂高脂饲料8周后,再给予蒸馏水、紫薯花色苷提取物(1. 67 mg·kg~(-1)·d~(-1)和8. 35 mg·kg~(-1)·d~(-1))或立普妥(阿托伐他汀钙,2 mg·kg~(-1)·d~(-1))灌胃8周。心脏取血检测小鼠血清的总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)及高密度脂蛋白胆固醇(HDL-C)水平;油红O和HE染色评估主动脉根部斑块面积和肝脏的脂肪变性程度; RT-q PCR方法检测主动脉和肝脏中炎症因子的表达。结果:与对照组比较,高脂饮食组小鼠血清的TC、LDL-C和HDL-C水平明显升高(P 0. 01),动脉的斑块面积明显增大(P 0. 01),肝脏的脂肪变性明显,白细胞介素1β(IL~(-1)β)、IL-6和单核细胞趋化蛋白1(MCP~(-1))的表达增加(P 0. 01),而过氧化物酶体增殖物激活受体α(PPAR-α)的表达降低(P 0. 05);高剂量紫薯花色苷提取物可以明显降低TC、TG和LDL-C水平(P 0. 01),减少动脉的斑块面积(P 0. 01),减轻肝脏的脂肪变性程度,同时还可以降低IL~(-1)β、IL-6和MCP~(-1)的表达(P 0. 05),提高PPAR-α的表达(P 0. 05)。结论:紫薯花色苷提取物可调节血脂,降低炎症细胞因子表达,从而抑制动脉粥样硬化的发展和高脂血症引起的肝组织脂肪变性。     

动脉粥样硬化小鼠肝脏脂质代谢相关的PPAR-γ/LXR-α/ABCG1通路及炎症因子的变化和化瘀祛痰方在其中的作用

目的:观察动脉粥样硬化(AS)小鼠肝脏脂质代谢相关的过氧化物酶体增殖物激活受体γ(PPAR-γ)/肝X受体α(LXR-α)/ATP结合盒转运体G1(ABCG1)通路和炎症因子的变化,以及化瘀祛痰方在其中的作用,探讨化瘀祛痰方对肝脏脂质代谢及炎症反应的影响及作用机制。方法:将24只ApoE-/-小鼠随机分为模型组、化瘀祛痰方组和辛伐他汀组,8只C57BL/6J小鼠作为正常对照组。除正常对照组给予基础饲料外,其余各组给予高脂饲料。造模12周后,灌胃给药,化瘀祛痰方组与辛伐他汀组给予相应药物,正常对照组与模型组给予等体积的生理盐水。8周后用全自动生物化学分析仪检测血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的含量;HE和油红O染色观察肝脏组织病理及脂质的变化情况;ELISA法检测肝脏游离脂肪酸(FFA)、TG、肿瘤坏死因子α(TNF-α)、Toll样受体4(TLR4)和白细胞介素1β(IL-1β)的含量;Western blot法检测PPAR-γ、LXR-α和ABCG1的蛋白表达。结果:与正常对照组比较,模型组小鼠血清TC、TG和LDL-C含量显著上升(P<0.01),HDL-C含量显著降低(P<0.01);肝脏脂肪变性,细胞变大,脂质沉积明显,FFA和TG含量显著上升(P<0.01),炎症因子TLR4、TNF-α和IL-1β的含量显著增加(P<0.01),脂质代谢通路相关因子PPAR-γ、LXR-α和ABCG1的蛋白表达显著降低(P<0.05或P<0.01)。与模型组比较,服用辛伐他汀和化瘀祛痰方可使小鼠血清TC、TG和LDL-C含量显著下降(P<0.05或P<0.01),HDL-C含量显著上升(P<0.01);肝脏脂肪变性减轻,脂质沉积不同程度降低,FFA和TG含量显著下降(P<0.05或P<0.01),TLR4、TNF-α和IL-1β含量显著降低(P<0.01),PPAR-γ、LXR-α和ABCG1的蛋白表达显著增高(P<0.05或P<0.01)。结论:化瘀祛痰方可能通过调控肝脏PPAR-γ/LXR-α/ABCG1通路及减弱肝脏TRL4介导的炎症反应来达到抗AS的作用。     

缺氧条件下HMGB1对HepG2细胞线粒体功能的影响

目的:探讨缺氧条件下高迁移率族蛋白B1(HMGB1)对人肝癌细胞系HepG2线粒体功能的影响及其机制。方法:将HMGB1小干扰RNA (HMGB1-siRNA)和阴性对照si RNA (si RNA-NC)分别转染入HepG2细胞,实验分为:缺氧(hypoxia)组、hypoxia+HMGB1-siRNA组和hypoxia+si RNA-NC组。流式细胞术检测各组细胞线粒体活性氧簇(mt ROS)含量和线粒体膜电位水平,RT-qPCR检测各组细胞线粒体DNA(mt DNA)拷贝数,ATP检测试剂盒检测各组细胞内ATP产生量,Western blot检测各组细胞线粒体生物合成相关分子表达的变化。结果:与hypoxia组和hypoxia+si RNA-NC组相比,当HMGB1表达被抑制后,细胞线粒体活性氧簇含量明显升高,线粒体膜电位水平、mt DNA拷贝数和ATP产生量明显下降(P 0. 05); Western blot结果显示,hypoxia+HMGB1-siRNA组的线粒体生物合成相关分子表达量下降(P 0. 05)。结论:缺氧环境下,HMGB1通过调控线粒体生物合成,诱导新生线粒体形成并维持细胞线粒体的正常功能。     

甘氨酸对小鼠体重及脂质代谢的影响

目的： 观察甘氨酸（Gly）对正常饮食和高脂饮食小鼠体重及血脂代谢的影响。 方法： 健康成年昆明种小鼠80只,雌雄各半，随机分4组：对照组、高脂饮食组（HF）、Gly组、Gly＋HF组，按各组要求分别给予正常饲料和高脂饲料喂养。以Gly 等药物定量腹腔注射处理。连续12 d，观察体重变化，实验末取血测定血脂4项（TC、TG、HDL-C、LDL），摘取雄性小鼠附睾周围脂肪垫和肾周脂肪垫，摘取雌性鼠腹部脂肪垫和肾周脂肪垫，称重并记录，留取肝脏组织并观察病理变化。 结果： HF组体重明显低于对照组，体脂含量无明显差异；Gly组的体重和体脂含量均明显低于对照组； Gly＋HF组体重和体脂含量均明显低于HF组； Gly组血清TC和TG的含量显著低于对照组； Gly＋HF组血脂4项与HF组相比没有显著差异；光镜下HF组肝组织可见弥漫性脂肪变性，Gly＋HF组肝组织脂肪变性少，肝细胞内脂滴小且少。 结论： Gly对正常饮食和高脂饮食的小鼠都有降低体重和体脂含量的作用，并能降低血脂，有预防肝脂肪变的作用。     

Parasitic Nematode-Induced Modulation of Body Weight and Associated Metabolic Dysfunction in Mouse Models of Obesity

Obesity is associated with a chronic low-grade inflammation characterized by increased levels of proinflammatory cytokines that are implicated in disrupted metabolic homeostasis. Parasitic nematode infection induces a polarized Th2 cytokine response and has been explored to treat autoimmune diseases. We investigated the effects of nematode infection against obesity and the associated metabolic dysfunction. Infection of RIP2-Opa1KO mice or C57BL/6 mice fed a high-fat diet (HFD) with Nippostrongylus brasiliensis decreased weight gain and was associated with improved glucose metabolism. Infection of obese mice fed the HFD reduced body weight and adipose tissue mass, ameliorated hepatic steatosis associated with a decreased expression of key lipogenic enzymes/mediators, and improved glucose metabolism, accompanied by changes in the profile of metabolic hormones. The infection resulted in a phenotypic change in adipose tissue macrophages that was characterized by upregulation of alternative activation markers. Interleukin-13 (IL-13) activation of the STAT6 signaling pathway was required for the infection-induced attenuation of steatosis but not for improved glucose metabolism, whereas weight loss was attributed to both IL-13/STAT6-dependent and -independent mechanisms. Parasitic nematode infection has both preventive and therapeutic effects against the development of obesity and associated features of metabolic dysfunction in mice.     

Fructose-induced steatosis in mice: role of plasminogen activator inhibitor-1, microsomal triglyceride transfer protein and NKT cells

Plasminogen activator inhibitor-1 (PAI-1) is an acute-phase protein known to be involved in alcoholic liver disease and hepatic fibrosis. In the present study, the hypothesis that PAI-1 is causally involved in the onset of fructose-induced hepatic steatosis was tested in a mouse model. Wild-type C57BL/6J and PAI-1?/? mice were fed with 30% fructose solution or water for 8 weeks. Markers of hepatic steatosis, expression of PAI-1, apolipoprotein B (ApoB), cluster of differentiation 1d (CD1d), markers of natural killer T (NKT) cells, protein levels of phospho-c-Met and tumor necrosis factor-α (TNF-α) were determined. Activity of the microsomal triglyceride transfer protein (MTTP) was measured in liver tissue. In comparison with water controls, chronic intake of 30% fructose solution caused a significant increase in hepatic triglycerides, PAI-1 expression and plasma alanine aminotransferase levels in wild-type mice. This effect of fructose feeding was markedly attenuated in PAI-1?/? mice. Despite no differences in portal endotoxin levels and hepatic TNF-α protein levels between fructose-fed groups, the protective effect of the loss of PAI-1 against the onset of fructose-induced steatosis was associated with a significant increase in phospho-c-Met, phospho Akt, expression of ApoB and activity of MTTP in livers of PAI-1?/? mice in comparison with fructose-fed wild types. Moreover, in PAI-1?/? mice, expressions of CD1d and markers of CD1d-reactive NKT cells were markedly higher than in wild-type mice; however, expression of markers of activation of CD1d-reactive NKT cells (eg, interleukin-15 and interferon-γ) were only found to be increased in livers of fructose-fed PAI-1?/? mice. Taken together, these data suggest that PAI-1 has a causal role in mediating the early phase of fructose-induced liver damage in mice through signaling cascades downstream of Kupffer cells and TNF-α.     

芝麻素对代谢综合征性脂肪肝大鼠肝组织iNOS和NT表达的影响

目的: 观察芝麻素对代谢综合征性脂肪肝大鼠肝组织诱导型一氧化氮合酶(iNOS)及硝基酪氨酸(NT)表达的影响。方法: 采用两肾一夹术伴高脂高糖饮食12周制备代谢综合征性脂肪肝大鼠模型。将成模大鼠随机分为模型组、芝麻素高、中、低剂量治疗组(120、60、30 mg·kg-1·d-1),另设假手术对照组;灌胃给药8周后,检测血清胆固醇(TC)、甘油三酯(TG)、游离脂肪酸(FFA)和肝组织超氧化物歧化酶(SOD)、丙二醛(MDA);应用Western blotting法检测大鼠肝组织中iNOS和NT的蛋白表达;HE染色观察肝组织病理变化。结果: 与模型组相比,高、中剂量治疗组芝麻素可降低大鼠血清TC、TG、FFA及MDA(P<0.05),提高SOD活性(P<0.05);抑制大鼠肝组织中iNOS和NT的蛋白表达(P<0.05),减轻肝组织脂肪变性。结论: 芝麻素对大鼠代谢综合征性脂肪肝病具有防治作用,其机制除了调脂作用外,可能还与下调iNOS、NT表达,减轻氧化应激损伤有关。     

Curcumin Protects Against Concanavalin A-Induced Hepatitis in Mice Through Inhibiting the Cytoplasmic Translocation and Expression of High Mobility Group Box 1

The aims of this study were to examine the anti-inflammatory effect of curcumin on concanavalin A (ConA) induced hepatitis in mice, and to elucidate its underlying molecular mechanisms. Mice received curcumin by gavage before ConA intravenous administration. The results showed that curcumin pretreatment attenuated ConA-induced hepatitis. Enzyme linked immunosorbent assay (ELISA) results showed that serum levels of high mobility group box 1 (HMGB1) increased at 4 h and reached its peak value at 12 h after challenge with ConA; but this increase was significantly inhibited by curcumin. Furthermore, curcumin significantly decreased the HMGB1 translocation from nucleus to cytoplasm of hepatocytes in ConA-induced mice. The levels of HMGB1 mRNA and protein expression in the liver were also significantly lowered in curcumin-treated mice. In addition, curcumin inhibited intrahepatic expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 protein. In conclusion, the results indicated that curcumin protected against ConA-induced hepatitis in mice; and the beneficial effects may be partly through inhibition of HMGB1 translocation in hepatocytes, release into the plasma and expression in livers.     

Pathology of the liver in obese and diabetic ob/ob and db/db mice fed a standard or high-calorie diet

Non‐alcoholic fatty liver disease (NAFLD) is one of the commonest liver diseases in Western countries. Although leptin deficient ob/ob and db/db mice are frequently used as murine models of NAFLD, an exhaustive characterization of their hepatic lesions has not been reported to date, particularly under calorie overconsumption. Thus, liver lesions were characterized in 78 ob/ob and db/db mice fed either a standard or high‐calorie (HC) diet, for one or three months. Steatosis, necroinflammation, apoptosis and fibrosis were assessed and the NAFLD activity score (NAS) was calculated. Steatosis was milder in db/db mice compared to ob/ob mice and was more frequently microvesicular. Although necroinflammation was usually mild in both genotypes, it was aggravated in db/db mice after one month of calorie overconsumption. Apoptosis was observed in db/db mice whereas it was only detected in ob/ob mice after HC feeding. Increased apoptosis was frequently associated with microvesicular steatosis. In db/db mice fed the HC diet for three months, fibrosis was aggravated while steatosis, necroinflammation and apoptosis tended to alleviate. This was associated with increased plasma β‐hydroxybutyrate suggesting an adaptive stimulation of hepatic mitochondrial fatty acid oxidation (FAO). Nevertheless, one‐third of these db/db mice had steatohepatitis (NAS ≥ 5), whereas none of the ob/ob mice developed non‐alcoholic steatohepatitis under the same conditions. Steatosis, necroinflammation, apoptosis and fibrosis are modulated by calorie overconsumption in the context of leptin deficiency. Association between apoptosis and microvesicular steatosis in obese mice suggests common mitochondrial abnormalities. Enhanced hepatic FAO in db/db mice is associated with fibrosis aggravation.