下瘀血汤对高脂饮食诱导的非酒精性脂肪性肝病小鼠模型的治疗作用及机制
DOI: 10.12449/JCH240412
Therapeutic effect of Xiayuxue decoction on a mouse model of nonalcoholic fatty liver disease induced by high-fat diet and its mechanism
-
摘要:
目的 探讨下瘀血汤调控核苷酸结合寡聚化结构域样受体含pyrin结构域蛋白6(NLRP6)抑制高脂饮食(HFD)诱导的小鼠非酒精性脂肪性肝病(NAFLD)的作用机制。 方法 15只雄性C57BL/6小鼠随机分为低脂饮食(LFD)组、HFD组和下瘀血汤-HFD(XYXD)组,每组各5只。测量肝功能指标ALT和AST、血脂代谢指标TG、TC水平;肝组织经过HE染色、油红O染色,观察小鼠组织形态、脂滴沉积;实时荧光定量PCR检测肝组织中炎症因子TNF-α、IL-1β、IL-6及NLRP6表达水平;Western Blot检测NLRP6、NF-κB和NF-κB p65蛋白水平;免疫组化检测NLRP6和CD68表达。棕榈酸(PA)、脂多糖(LPS)和下瘀血汤含药血清处理鼠Raw264.7细胞,检测炎症情况。计量资料多组间比较采用单因素方差分析,进一步两两比较采用LSD-t检验。 结果 与LFD组比较,HFD组血清ALT、AST和TC、TG水平显著升高(P值均<0.05)。肝组织病理学显示,HFD组肝脂肪变性明显,NAS评分显著升高(P<0.05);实时荧光定量PCR结果显示,IL-1β、IL-18等炎症相关因子显著升高,NLRP6表达显著下调(P值均<0.05)。免疫组化显示NLRP6表达与巨噬细胞标志物CD68重合。Western Blot显示,NLRP6表达下调后,磷酸化的NF-κB p65(p-NF-κB p65)显著上调(P<0.05)。与HFD组相比,下瘀血汤可有效改善HFD小鼠的肝脏炎症,上调NLRP6的表达,下调p-NF-κB p65(P<0.05)。PA处理Raw264.7细胞后下调NLRP6,促进炎症进展(P<0.05);下瘀血汤处理可上调NLRP6,抑制炎症和NF-κB(P<0.05)。 结论 下瘀血汤可显著改善HFD诱导NAFLD小鼠模型的肝脂肪变性和炎症,调控NLRP6/NF-κB减轻巨噬细胞活化可能是其作用机制之一。 -
关键词:
- 非酒精性脂肪性肝病 /
- 下瘀血汤 /
- 巨噬细胞 /
- NLR蛋白质类 /
- 小鼠, 近交C57BL
Abstract:Objective To investigate the mechanism of action of Xiayuxue decoction in inhibiting nonalcoholic fatty liver disease (NAFLD) induced by high-fat diet in mice by regulating nucleotide binding oligomerization domain like receptor containing pyrin domain protein 6 (NLRP6). Methods A total of 15 male C57BL/6 mice were randomly divided into low-fat diet (LFD) group, high-fat diet (HFD) group, and Xiayuxue decoction-HFD group (XYXD group), with 5 mice in each group. Liver function parameters (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) and blood lipid metabolic indicators (triglycerides [TG] and total cholesterol [TC]) were measured; HE staining and oil red O staining were performed for liver tissue to observe histomorpholoty and lipid droplet deposition; quantitative real-time PCR was used to measure the expression levels of inflammatory factors (tumor necrosis factor-α [TNF-α], interleukin-1β [IL-1β], interleukin-18 [IL-18], and NLRP6) in liver tissue; Western blot was used to measure the protein expression levels of NLRP6, nuclear factor-kappa B (NF-κB), and NF-κB p65; immunohistochemistry was used to measure the expression of NLRP6 and CD68. Mouse Raw264.7 cells were treated with palmitic acid (PA), lipopolysaccharide, and serum containing Xiayuxue decoction to observe inflammation. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. Results Compared with the LFD group, the HFD group had significant increases in the serum levels of ALT, AST, TC, and TG (all P<0.05). Liver histopathological examination showed that the HFD group had marked hepatic steatosis and a signficant increase in NAS score (P<0.05), and quantitative real-time PCR showed significant increases in the inflammatory factors such as IL1β and IL-18 and a significant reduction in the expression of NLRP6 (all P<0.05). Immunohistochemistry showed that the expression of NLRP6 showed a similar trend as that of the macrophage marker CD68. Western blot showed that after the downregulation of NLRP6 expression, there was a significant increase in phosphorylated NF-κB p65 (P<0.05). Compared with the HFD group, Xiayuxue decoction effectively improved liver inflammation, upregulated the expression of NLRP6, and downregulated phosphorylated NF-κB p65 in HFD mice (all P<0.05). After Raw264.7 cells were treated with PA, NLRP6 was downregulated to promote the progression of inflammation (P<0.05), and treatment with Xiayuxue decoction could upregulate NLRP6 and inhibit inflammation NF-κB (P<0.05). Conclusion Xiayuxue decoction can effectively improve hepatic steatosis and liver inflammation in a mouse model of NAFLD, possibly by regulating NLRP6/NF-κB to alleviate macrophage activation. -
Key words:
- Non-alcoholic Fatty Liver Disease /
- Xia Yu Xue Tang /
- Macrophages /
- NLR Proteins /
- Mice, Inbred C57BL
-
表 1 引物序列表
Table 1. Primer sequence table
基因 上游(5′-3′) 下游(5′-3′) 18S GTAACCCGTTGAACCCCATT CCATCCAATCGGTAGTAGCG TNF-α ATGAGAGGGAGGCCATTTG CAGCCTCTTCTCATTCCTGC IL-1β AGGTCAAAGGTTTGGAAGCA TGAAGCAGCTATGGCAACTG CD68 ACATTGTATTCCACCGCCAT CATCCCCACCTGTCTCTC IL-18 AACCGCAGTAATACGGAGCA CTGGTCTGGGATTCGTTGG NLRP6 CTCGCTTGCTAGTGACTACAC AGTGCAAACAGCGTCTCGTT Caspase-1 ACAAGGCACGGGACCTATG TCCCAGTCAGTCCTGGAAATG ASC TGAGCAGCTGCAAACGACTA AGGAGGAACAGTTAAGCGCC 表 2 各组小鼠血清转氨酶及血脂水平
Table 2. Serum transaminase and blood lipid levels of mice in each group
组别 动物数(只) ALT(U/L) AST(U/L) TC(μmol/L) TG(μmol/L) LFD组 5 7.94±3.15 4.31±2.63 1.19±0.08 0.53±0.19 HFD组 5 85.31±31.991) 52.06±19.451) 1.87±0.341) 2.68±1.291) XYXD组 5 23.17±8.572) 15.36±6.732) 1.34±0.232) 1.14±0.172) F值 22.76 21.77 10.08 10.49 P值 0.000 1 0.000 1 0.003 0.002 注:与LFD组比较,1)P<0.05;与HFD组比较,2)P<0.05。 表 3 各组小鼠肝脏油红染色半定量及NAS评分比较
Table 3. Semi quantitative oil red staining and NAS score of liver in each group of mice
组别 动物数(只) 油红染色阳性面积(%) NAS评分 LFD组 5 0.83±0.26 1.33±0.21 HFD组 5 34.20±4.871) 5.50±0.431) XYXD组 5 6.27±1.202) 3.17±0.482) F值 34.52 28.72 P值 0.000 1 0.000 1 注:与LFD组比较,1)P<0.05;与HFD组比较,2)P<0.05。 表 4 各组小鼠肝组织中炎症相关因子mRNA相对表达量比较
Table 4. Comparison of relative expression levels of inflammatory related factor mRNA in liver tissues of mice in each group
组别 IL-1β TNF-α CD68 IL-18 NLRP6 Caspase-1 ASC LFD组 1.00±0.61 0.83±0.45 1.00±0.25 1.00±0.30 1.00±0.24 1.03±0.45 1.00±0.29 HFD组 2.63±0.661) 12.19±8.671) 3.81±2.911) 4.43±3.391) 0.41±0.251) 4.87±0.911) 2.50±1.141) XYXD组 1.56±0.992) 2.77±2.022) 1.56±0.412) 1.80±0.802) 0.76±0.302) 2.36±0.722) 1.43±0.882) F值 11.44 15.74 8.58 8.80 12.62 36.67 8.37 P值 0.000 2 0.000 1 0.001 0.001 0.000 1 <0.000 1 0.001 注:与LFD组比较,1)P<0.05;与HFD组比较,2)P<0.05。 表 5 各组小鼠肝组织中CD68和NLRP6含量半定量分析
Table 5. Semiquantitative analysis of CD68 and NLRP6 content in liver tissue of mice in each group
组别 CD68阳性面积(%) NLRP6阳性面积(%) LFD组 1.27±0.99 5.22±2.20 HFD组 11.11±3.901) 0.69±0.361) XYXD组 5.56±1.672) 3.84±2.17 F值 11.56 7.98 P值 0.009 0.020 注:与LFD组比较,1)P<0.05;与HFD组比较,2)P<0.05。 表 6 各组小鼠肝组织中p-NF-κB和NLRP6含量灰度值半定量分析
Table 6. Semiquantitative analysis of p-NF-κB and NLRP6 content in liver of mice in each group
组别 p-NF-κB灰度值 NLRP6灰度值 LFD组 4.89±0.86 17.43±2.06 HFD组 23.31±2.441) 4.42±1.201) XYXD组 11.91±0.842) 14.52±2.212) F值 35.16 13.25 P值 0.000 1 0.000 5 注:与LFD组比较,1)P<0.05;与HFD组比较,2)P<0.05。 表 7 体外实验中炎症因子mRNA相对表达量比较
Table 7. Comparison of relative expression levels of inflammatory factor mRNA in vitro
组别 IL-1β TNF-α IL-18 NLRP6 对照组 1.00±0.05 1.00±0.15 1.00±0.34 1.00±0.14 PA组 4.87±0.211) 3.55±0.011) 5.57±1.951) 0.63±0.041) PA+XYXD组 2.28±0.392) 2.76±0.532) 2.71±0.112) 1.28±0.292) F值 177.64 51.00 12.16 9.32 P值 0.000 1 0.000 1 0.008 0.014 注:与对照组比较,1)P<0.05;与PA组比较,2)P<0.05。 表 8 体外试验中p-NF-κB和NLRP6含量灰度值半定量分析
Table 8. Semiquantitative analysis of p-NF-κB and NLRP6 content in vitro
组别 p-NF-κB灰度值(%) NLRP6灰度值(%) 对照组 0.31±0.16 54.57±3.44 XYXD组 3.27±0.08 63.25±2.06 PA组 99.13±3.031) 21.42±2.021) PA+XYXD组 32.83±10.832) 53.53±14.682) F值 262.96 19.04 P值 0.000 1 0.005 注:与对照组比较,1)P<0.05;与PA组比较,2)P<0.05。 -
[1] NATARAJAN Y, KRAMER JR, YU X, et al. Risk of cirrhosis and hepatocellular cancer in patients with NAFLD and normal liver enzymes[J]. Hepatology, 2020, 72( 4): 1242- 1252. DOI: 10.1002/hep.31157. [2] ZHOU F, ZHOU JH, WANG WX, et al. Unexpected rapid increase in the burden of NAFLD in China from 2008 to 2018: A systematic review and meta-analysis[J]. Hepatology, 2019, 70( 4): 1119- 1133. DOI: 10.1002/hep.30702. [3] WU L, ZHANG J, MA WT, et al. Xiayuxue decoction inhibits methionine-choline-deficient-induced nonalcoholic steatohepatitis in mice[J/OL]. Chin J Liver Dis Electron Version, 2018, 10( 3): 48- 55. DOI: 10.3969/j.issn.1674-7380.2018.03.009.吴柳, 张洁, 马文婷, 等. 下瘀血汤对胆碱蛋氨酸缺乏诱导的小鼠非酒精性脂肪性肝炎的抑制作用[J/OL]. 中国肝脏病杂志(电子版), 2018, 10( 3): 48- 55. DOI: 10.3969/j.issn.1674-7380.2018.03.009. [4] KLEINER DE, BRUNT EM, VAN NATTA M, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease[J]. Hepatology, 2005, 41( 6): 1313- 1321. DOI: 10.1002/hep.20701. [5] SHI XJ, TAN X, ZHANG XS, et al. Discussion on medication rule of non-alcoholic fatty liver disease based on national patent of traditional Chinese medicine compound[J]. Chin Med Herald, 2022, 19( 20): 148- 151, 156.施晓军, 谭祥, 章晓思, 等. 基于国家中药复方专利探讨非酒精性脂肪性肝病的用药规律[J]. 中国医药导报, 2022, 19( 20): 148- 151, 156. [6] Branch of Gastrointestinal Diseases, China Association of Chinese Medicine. Expert consensus on TCM diagnosis and treatment of nonalcoholic fatty liver disease(2017)[J]. J Clin Hepatol, 2017, 33( 12): 2270- 2274. DOI: 10.3969/j.issn.1001-5256.2017.12.002.中华中医药学会脾胃病分会. 非酒精性脂肪性肝病中医诊疗专家共识意见(2017)[J]. 临床肝胆病杂志, 2017, 33( 12): 2270- 2274. DOI: 10.3969/j.issn.1001-5256.2017.12.002. [7] ALSHAWSH MA, ALSALAHI A, ALSHEHADE SA, et al. A comparison of the gene expression profiles of non-alcoholic fatty liver disease between animal models of a high-fat diet and methionine-choline-deficient diet[J]. Molecules, 2022, 27( 3): 858. DOI: 10.3390/molecules27030858. [8] BIJNEN M, JOSEFS T, CUIJPERS I, et al. Adipose tissue macrophages induce hepatic neutrophil recruitment and macrophage accumulation in mice[J]. Gut, 2018, 67( 7): 1317- 1327. DOI: 10.1136/gutjnl-2016-313654. [9] KAZANKOV K, JØRGENSEN SMD, THOMSEN KL, et al. The role of macrophages in nonalcoholic fatty liver disease and nonalcoholic steatohepatitis[J]. Nat Rev Gastroenterol Hepatol, 2019, 16( 3): 145- 159. DOI: 10.1038/s41575-018-0082-x. [10] WANG XJ, DE CARVALHO RIBEIRO M, IRACHETA-VELLVE A, et al. Macrophage-specific hypoxia-inducible factor-1α contributes to impaired autophagic flux in nonalcoholic steatohepatitis[J]. Hepatology, 2019, 69( 2): 545- 563. DOI: 10.1002/hep.30215. [11] HENAO-MEJIA J, ELINAV E, JIN CC, et al. Inflammasome-mediated dysbiosis regulates progression of NAFLD and obesity[J]. Nature, 2012, 482( 7384): 179- 185. DOI: 10.1038/nature10809. [12] CORRIDONI D, SIMMONS A. Innate immune receptors for cross-presentation: The expanding role of NLRs[J]. Mol Immunol, 2019, 113: 6- 10. DOI: 10.1016/j.molimm.2017.11.028. [13] MAINZ RE, ALBERS S, HAQUE M, et al. NLRP6 inflammasome modulates disease progression in a chronic-plus-binge mouse model of alcoholic liver disease[J]. Cells, 2022, 11( 2): 182. DOI: 10.3390/cells11020182. [14] LI MF, CHEN YT, SHI JR, et al. NLRP6 deficiency aggravates liver injury after allogeneic hematopoietic stem cell transplantation[J]. Int Immunopharmacol, 2019, 74: 105740. DOI: 10.1016/j.intimp.2019.105740.