越来越多的证据表明,脂质代谢紊乱和肠道菌群失调与非酒精性脂肪性肝病(NAFLD)的进展有关。促凋亡p53蛋白2(ASPP2)已被报道通过调节脂质代谢来防止肝细胞损伤。但机制在很大程度上仍然未知。在这项研究中,我们调查了ASPP2缺乏对NAFLD的影响,使用ASPP2全局杂合子敲除(ASPP2+/-)小鼠的脂质代谢和肠道菌群。
ASPP2+/-Balb/c小鼠饲喂蛋氨酸和胆碱缺乏饮食3、10和40天,以诱导NAFLD的早期和晚期,分别。收集新鲜的粪便样品,然后进行16SrRNA测序。使用HPLC-MRM相对定量分析来鉴定肝脂质谱的变化。先天免疫的表达水平-,确定脂质代谢和肠道通透性相关基因。进行了Spearman等级相关分析,以确定ASPP2缺乏小鼠的肝脏介质和长链脂肪酸与肠道微生物群之间可能的相关性。
与WT对照相比,ASPP2缺乏小鼠在第10天发展为中度脂肪变性,在第40天发展为重度脂肪变性。肝脏长链omega-3脂肪酸的水平,二十碳五烯酸(EPA,20:5n-3)和二十二碳六烯酸(DHA,22:6n-3),在ASPP+/-小鼠中在第10天降低并在第40天增加。粪便菌群分析显示α和β多样性显著增加,以及门的肠道微生物群的组成,类,订单,家庭,属,ASPP2+/-小鼠的物种水平。此外,ASPP缺乏小鼠表现出受损的肠屏障功能,与化学屏障相关的基因表达降低(REG3B,REG3G,溶菌酶和IAP),和先天免疫组分(TLR4和TLR2)的表达增加。此外,肠道菌群与脂肪酸的相关性分析显示,EPA与双歧杆菌家族呈显著负相关。
我们的研究结果表明,ASPP2缺乏促进NAFLD的进展,脂肪酸代谢和肠道菌群失调的改变。长链脂肪酸EPA与双歧杆菌丰度呈显著负相关,这是ASPP2缺乏症小鼠NAFLD的特定特征。完全正确,研究结果为ASPP2在脂肪酸代谢失调和肠道菌群失调中的作用机制提供了证据。
Growing evidence indicates that lipid metabolism disorders and gut microbiota dysbiosis were related to the progression of non-alcoholic fatty liver disease (NAFLD). Apoptosis-stimulating p53 protein 2 (
ASPP2) has been reported to protect against hepatocyte injury by regulating the lipid metabolism, but the mechanisms remain largely unknown. In this study, we investigate the effect of
ASPP2 deficiency on NAFLD, lipid metabolism and gut microbiota using
ASPP2 globally heterozygous knockout (
ASPP2+/-) mice.
ASPP2+/- Balb/c mice were fed with methionine and choline deficient diet for 3, 10 and 40 day to induce an early and later-stage of NAFLD, respectively. Fresh fecal samples were collected and followed by 16S rRNA sequencing. HPLC-MRM relative quantification analysis was used to identify changes in hepatic lipid profiles. The expression level of innate immunity-, lipid metabolism- and intestinal permeability-related genes were determined. A spearman\'s rank correlation analysis was performed to identify possible correlation between hepatic medium and long-chain fatty acid and gut microbiota in ASPP2-deficiency mice.
Compared with the WT control,
ASPP2-deficiency mice developed moderate steatosis at day 10 and severe steatosis at day 40. The levels of hepatic long chain omega-3 fatty acid, eicosapentaenoic (EPA, 20:5 n-3) and docosahexaenoic (DHA, 22:6 n-3), were decreased at day 10 and increased at day 40 in ASPP+/- mice. Fecal microbiota analysis showed significantly increased alpha and beta diversity, as well as the composition of gut microbiota at the phylum, class, order, family, genus, species levels in ASPP2+/- mice. Moreover, ASPP-deficiency mice exhibited impaired intestinal barrier function, reduced expression of genes associated with chemical barrier (REG3B, REG3G, Lysozyme and IAP), and increased expression of innate immune components (TLR4 and TLR2). Furthermore, correlation analysis between gut microbiota and fatty acids revealed that EPA was significantly negatively correlated with Bifidobacterium family.
Our findings suggested that ASPP2-deficiency promotes the progression of NAFLD, alterations in fatty acid metabolism and gut microbiota dysbiosis. The long chain fatty acid EPA was significantly negatively correlated with Bifidobacterial abundance, which is a specific feature of NAFLD in ASPP2-deficiency mice. Totally, the results provide evidence for a mechanism of ASPP2 on dysregulation of fatty acid metabolism and gut microbiota dysbiosis.