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ObjectiveTo investigate the mechanism of Xuefu Zhuyu capsules against atherosclerosis via regulating polarization of macrophages based on Notch1/jagged canonical Notch ligand 1（Jagged1）/Hes family BHLH transcription factor 1（Hes1） signaling pathway. MethodThe mouse models with atherosclerosis were prepared by feeding the mice with an ApoE-/- high-fat diet for four weeks， and they were randomly divided into the model group， Xuefu Zhuyu capsule group， and atorvastatin group. C57BL/6 mice were fed as a normal group. The Xuefu Zhuyu capsule group was intragastrically given Xuefu Zhuyu capsules （0.728 g·kg-1·d-1）， and the atorvastatin group was intragastrically given atorvastatin tablet （6.07 mg·kg-1·d-1）. The normal group and the model group were given equal volume of the deionized water by intragastric administration， and the intervention lasted for 12 weeks. Aortic plaque morphology was observed by hematoxylin-eosin （HE） staining， and aortic plaque area and lipid deposition were observed by oil red O staining. The positive expression levels of CD86 and CD206 in aortic tissue were detected by immunohistochemistry， and serum levels of tumor necrosis factor （TNF）-α， interleukin（IL）-1β， transforming growth factor （TGF）-β1， and IL-10 were detected by enzyme-linked immunosorbent assay （ELISA）. The relative mRNA expressions of inducible nitric oxide synthase （iNOS）， arginase-1 （Arg-1）， Notch1， Jagged1， and Hes1 in aortic tissue were detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. The relative protein expression of iNOS， Arg-1， Notch1， Jagged1， and Hes1 in aortic tissue was detected by Western blot. ResultCompared with the normal group， the model group had significant aortic plaque and lipid deposition， and the expression levels of pro-inflammatory cytokines TNF-α and IL-1β were increased （P<0.01）. The expression level of anti-inflammatory cytokine TGF-β1 showed a downward trend， but the difference was not statistically significant. The mRNA and protein expressions of iNOS were increased （P<0.01）. The protein expression of Arg-1 was decreased （P<0.01）， and the mRNA expression of related pathway molecule Jagged1， as well as the protein expressions of Notch1， Jagged1， and Hes1 were increased in the model group （P<0.05， P<0.01）. Compared with those in the model group， the plaque area and lipid deposition had a decreasing trend in the Xuefu Zhuyu capsule group， and the expressions of TNF-α and IL-1β showed a downward trend. The expression of TGF-β1 was increased （P<0.05）， and the expression of macrophage marker CD86 was decreased. The mRNA and protein expressions of iNOS were decreased （P<0.01）. The mRNA and protein expressions of Arg-1 were increased （P<0.05， P<0.01）. Furthermore， the mRNA and protein expressions of Notch1， Jagged1， and Hes1 were decreased （P<0.01）. ConclusionXuefu Zhuyu capsules can reduce aortic plaque area and lipid deposition in mice with atherosclerosis， alleviate inflammation， inhibit M1 macrophages， and promote the expression of M2 macrophages， and the mechanism may be related to the regulation of Notch1/Jagged1/Hes1 signaling pathway.
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Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Fat accumulation "sensitizes" the liver to insult and leads to nonalcoholic steatohepatitis (NASH). G protein-coupled receptor 35 (GPR35) is involved in metabolic stresses, but its role in NAFLD is unknown. We report that hepatocyte GPR35 mitigates NASH by regulating hepatic cholesterol homeostasis. Specifically, we found that GPR35 overexpression in hepatocytes protected against high-fat/cholesterol/fructose (HFCF) diet-induced steatohepatitis, whereas loss of GPR35 had the opposite effect. Administration of the GPR35 agonist kynurenic acid (Kyna) suppressed HFCF diet-induced steatohepatitis in mice. Kyna/GPR35 induced expression of StAR-related lipid transfer protein 4 (STARD4) through the ERK1/2 signaling pathway, ultimately resulting in hepatic cholesterol esterification and bile acid synthesis (BAS). The overexpression of STARD4 increased the expression of the BAS rate-limiting enzymes cytochrome P450 family 7 subfamily A member 1 (CYP7A1) and CYP8B1, promoting the conversion of cholesterol to bile acid. The protective effect induced by GPR35 overexpression in hepatocytes disappeared in hepatocyte STARD4-knockdown mice. STARD4 overexpression in hepatocytes reversed the aggravation of HFCF diet-induced steatohepatitis caused by the loss of GPR35 expression in hepatocytes in mice. Our findings indicate that the GPR35-STARD4 axis is a promising therapeutic target for NAFLD.