Kinsenoside Protects Against Radiation-Induced Liver Fibrosis via Downregulating Connective Tissue Growth Factor Through TGF-β1 Signaling

Abstract

Radiation-induced liver fibrosis (RILF) is a serious complication of the radiotherapy of liver cancer, which lacks effective prevention and treatment measures. Kinsenoside (KD) is a monomeric glycoside isolated from Anoectochilus roxburghii, which has been reported to show protective effect on the early progression of liver fibrosis. However, the role of KD in affecting RILF remains unknown. Here, we found that KD alleviated RILF via downregulating connective tissue growth factor (CTGF) through TGF-β1 signaling. Sprague-Dawley rats were administered with 20 mg/kg KD per day for 8 weeks after a single 30Gy irradiation on the right part of liver, and tumor-bearing nude mice were administered with 30 mg/kg KD per day after a single fraction of 10Gy on the tumor inoculation site. Twenty-four weeks postirradiation, we found that the administration of KD after irradiation resulted in decreased expression of α-SMA and fibronectin in the liver tissue while had no adverse effect on the tumor radiotherapy. Besides, KD inhibited the activation of hepatic stellate cells (HSCs) postirradiation via targeting CTGF as indicated by the transcriptome sequencing. Results of the pathway enrichment and immunohistochemistry suggested that KD reduced the expression of TGF-β1 protein after radiotherapy, and exogenous TGF-β1 induced HSCs to produce α-SMA and other fibrosis-related proteins. The content of activated TGF-β1 in the supernatant decreased after treatment with KD. In addition, KD inhibited the expression of the fibrosis-related proteins by regulating the TGF-β1/Smad/CTGF pathway, resulting in the intervention of liver fibrosis. In conclusion, this study revealed that KD alleviated RILF through the regulation of TGFβ1/Smad/CTGF pathway with no side effects on the tumor therapy. KD, in combination with blocking the TGF-β1 pathway and CTGF molecule or not, may become the innovative and effective treatment for RILF.

ALKBH5‐mediated m6A demethylation of TIRAP mRNA promotes radiation‐induced liver fibrosis and decreases radiosensitivity of hepatocellular carcinoma

“…The common motif of m 6 A in LX2 cells was GGACUU (Figure S1D). Compared with the control group, there were less unique m 6 A peaks (10 523 vs. 11 547) and less genes with unique modification peaks (9581 vs. 10 261) in ALKBH5 knockdown group (Figure S1E). There were 3549 differential m 6 A peaks (fold change ≥ 2, p < .05) and 485 differentially expressed genes (fold change ≥ 2, p < .05) in ALKBH5 knockdown group, and 56 genes that showed differences in m 6 A peaks and gene expression were obtained by integrated analysis.…”

“… 5 Hepatic stellate cell (HSC) is the key effector cell in the process of RILF. 6 Radiation‐induced HSC activation is a complex process involving a variety of cytokines and pathways. Our previous studies reported that radiation induces HSC proliferation and activation through nuclear factor‐kappa B (NF‐κB) and c‐Jun N‐terminal kinase (JNK)/Smad2 pathways, which promotes RILF development.…”

“…17,18 Ten-eleven translocation 2 is also an Fe/α-ketoglutarate-dependent enzyme that converts 5methylcytosine to 5-hydroxy-methylcytosine on DNA. 19,20 Different from ten-eleven translocation 2, ALKBH5 mainly takes part in m 6 A modification of RNA. 21 As a demethylase, ALKBH5 removes m 6 A from RNA when RNA binds to the active site of ALKBH5 in a 5′-3′ orientation and thus affects the regulation of RNA expression.…”

Advances in the therapeutic application and pharmacological properties of kinsenoside against inflammation and oxidative stress-induced disorders

“…During the liver damage, HSCs in a resting condition are stimulated by fibrogenic mediators such as cytokines and are transformed to activated myofibroblasts, which produce and secrete excessive fibrosis-related proteins such as collagen and fibronectin to the perisinusoidal space, thereby leading to distortion of tissue structure and hepatic dysfunction ( Wu et al, 2007 ; Wu et al, 2010 ; Hsieh et al, 2011 ; Gao et al, 2021 ; Nie et al, 2022 ). Since a series of preclinical data have confirmed the positive roles of the inflammatory response and oxidative stress in exacerbating liver fibrosis, strategies impeding inflammatory cascades or relieving ROS burden display excellent anti-fibrotic abilities ( Binatti et al, 2022 ; Nassir, 2022 ).…”

“…Additionally, the switching of M1 macrophages to the M2 phenotype and inactivation of TLR4 signal pathway was implicated in the anti-fibrotic effects of KD. Interestingly, TGF-β1 was described as an inflammation-inhibiting factor and was up-regulated by KD in the model of autoimmune hepatitis, while it was reported that KD limited the expression of TGF-β1 to mitigate the development of fibrosis in the damaged liver ( Xiang et al, 2016 ; Nie et al, 2022 ). Several factors, including animal model type, inductive agent, stimulation dose and duration, and disorder stage might explain this paradox.…”