ABSTRACT
ObjectiveTo investigate the role and mechanism of podoplanin （PDPN） in hepatic stellate cell （HSC） activation and liver fibrosis. MethodsLiver biopsy samples were collected from 75 patients with chronic hepatitis B who attended Department of Infectious Diseases， Putuo Hospital Affiliated to Shanghai University of Traditional Chinese Medicine， for the first time from September 2019 to June 2022， and RT-PCR and immunohistochemistry were used to measure the expression of PDPN in liver tissue of patients in different stages of liver fibrosis. A total of 12 male C57/BL6 mice were randomly divided into control group and model group. The mice in the model group were given intraperitoneal injection of 10% CCl4， and those in the control group were injected with an equal volume of olive oil， for 6 weeks. HE staining and Sirius Red staining were used to observe liver histopathological changes； primary mouse liver cells were separated to measure the mRNA expression of PDPN in various types of cells； primary mouse HSCs were treated with PDPN protein， followed by treatment with the NF-κB inhibitor BAY11-708， to measure the expression of inflammatory factors in HSCs induced by PDPN. The independent-samples t test was used for comparison of normally distributed continuous data between two groups； a one-way analysis of variance was used for comparison between multiple groups， and the least significant difference t-test was used for further comparison between two groups. The Spearman correlation analysis was used to investigate data correlation. ResultsAs for the liver biopsy samples， there was a relatively low mRNA expression level of PDPN in normal liver， and there was a significant increase in the mRNA expression level of PDPN in liver tissue of stage S3 or S4 fibrosis （all P<0.001）. Immunohistochemical staining showed that PDPN was mainly expressed in the fibrous septum and the hepatic sinusoid， and the PDPN-positive area in S4 liver tissue was significantly higher than that in S0 liver tissue （t=8.892， P=0.001）. In normal mice， PDPN was mainly expressed in the hepatic sinusoid， and there was a significant increase in the expression of PDPN in CCl4 model mice （t=0.95， P<0.001）， mainly in the fibrous septum. RT-PCR showed a significant increase in the mRNA expression of PDPN in the CCl4 model mice （t=11.25， P=0.002）. Compared with hepatocytes， HSCs， Kupffer cells， and bile duct endothelial cells， hepatic sinusoidal endothelial cells showed a significantly high expression level of PDPN （F=20.56， P<0.001）. Compared with the control group， the primary mouse HSCs treated by PDPN protein for 15 minutes showed significant increases in the mRNA expression levels of the inflammation-related factors TNFα， CCL3， CXCL1， and CXCR1 （all P<0.05）， and there were significant reductions in the levels of these indicators after treatment with BAY11-7082 （all P<0.05）. ConclusionThere is an increase in the expression of PDPN mainly in hepatic sinusoidal endothelial cells during liver fibrosis， and PDPN regulates HSC activation and promotes the progression of liver fibrosis via the NF-κB signaling pathway.
ABSTRACT
Objective To investigate the therapeutic effect of Taohong Siwu decoction on a mouse model of carbon tetrachloride (CCl 4 )-induced liver fibrosis and its mechanism of action. Methods A total of 24 male C57BL/6 mice were randomly divided into normal group, model group, and Taohong Siwu decoction group, with 8 mice in each group. The mice in the model group and the Taohong Siwu decoction group were given intraperitoneal injection of 10% CCl 4 , and Taohong Siwu decoction was given by gavage since week 3 for 4 consecutive weeks. Liver function [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)] was measured, and liver pathomorphology was observed. Real-time PCR was used to measure the mRNA expression of α-smooth muscle actin (α-SMA), hyaluronic acid synthase-2 (HAS-2), and collagen type Ⅰ(Col1), and Western blotting was used to measure the protein expression of α-SMA, Col1, and HAS-2. Primary hepatic stellate cells (HSCs) were isolated, and HAS-2 was silenced by siRNA to observe its influence on HSC activation. The t -test was used for comparison of continuous data between two groups; a one-way analysis of variance was used for comparison between multiple groups, and the SNK or least significant difference t -test was used for further comparison between two groups. Results Compared with the normal group, the model group had significant increases in serum liver function parameters (ALT, AST) and the Taohong Siwu decoction group had significant reductions in the serum levels of ALT and AST (all P < 0.01). Pathological staining showed that the model group had marked inflammatory cell infiltration and formation of fibrous septa by proliferated collagen fibers, and the Taohong Siwu decoction group had loose fibrous septa and alleviated inflammatory cell infiltration. Compared with the model group, the Taohong Siwu decoction group had significant reductions in the mRNA and protein expression of α-SMA and Col1(all P < 0.001). Compared with the normal group, the model group had a significant increase in the mRNA expression level of HAS-2 in liver tissue ( t =6.14, P < 0.05), and compared with the model group, the Taohong Siwu decoction group had a significant reduction in the protein expression level of HAS-2 (0.29±0.10 vs 1.00±0.12, t =70.73, P < 0.001). After HAS-2 was silenced by siRNA, the Si HAS-2+transforming growth factor β (TGFβ) group (treated with TGFβ) had significant reductions in the mRNA expression levels of α-SMA and Col-Ⅰ compared with the NC+TGFβ group ( P < 0.01). Conclusion Taohong Siwu decoction exerts a marked therapeutic effect on CCl 4 -induced liver fibrosis in mice by inhibiting HAS-2.
ABSTRACT
ObjectiveTo investigate whether Xiayuxue decoction exerts an anti-liver fibrosis effect by inhibiting glial cell line-derived neurotrophic factor (GDNF). MethodsA total of 24 C57BL/6 mice were randomly divided into control group, model group, and Xiayuxue decoction group. The mice in the model group and the Xiayuxue decoction group were given intraperitoneal injection of 10% CCl4, and those in the Xiayuxue decoction group were given 0.4678 g/kg Xiayuxue decoction by gavage since week 4. The liver function parameters alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, and liver histopathology was observed. Immunohistochemistry was used to measure the protein expression of alpha-smooth muscle actin (α-SMA) and GDNF. GFP-Col-HSC and human primary hepatic stellate cells (HSCs) were treated with GDNF (10 ng/ml), and HSC activation was measured. 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. ResultsCompared with the control group, the model group had significant increases in the levels of ALT and AST, and compared with the model group, the Xiayuxue decoction group had significant reductions in the levels of ALT and AST (all P＜0.01). Liver histopathology showed that the model group had marked inflammatory cell infiltration and formation of fibrous septa by proliferated collagen fibers, and the Xiayuxue decoction group had loose fibrous septa and alleviated inflammatory cell infiltration. Immunohistochemistry showed that compared with the control group, the model group had significant increases in the expression of α-SMA and GDNF (both P＜0.01), which were observed in fibrous septa, and compared with the model group, the Xiayuxue decoction group had significant reductions in the expression of α-SMA and GDNF (both P＜0.05). Western blotting showed that the control group had relatively low expression of GDNF in liver tissue, the formation of liver fibrosis at week 6 of CCl4 modeling, and an around 10-fold increase in the expression of GDNF, and the Xiayuxue decoction group had significantly inhibited protein expression of GDNF (P＜0.01); there were significant increases in the expression of α-SMA and collagen type I α1 (Col1) in mice with liver fibrosis, with significant reductions in α-SMA and Col1 after treatment with Xiayuxue decoction (all P＜0.01). The in vitro experiment showed that GDNF induced the significant increases in the protein expression of α-SMA and Col1 in HSCs, which was significantly inhibited by Xiayuxue decoction (all P＜0.01). ConclusionThe expression of GDNF is significantly upregulated in the formation of liver fibrosis. GDNF can induce HSC activation, and Xiayuxue decoction can exert an anti-liver fibrosis effect by inhibiting GDNF.