Hepatic and HSC-specific sorafenib effects in rats with established secondary biliary cirrhosis

Abstract

Portal hypertension in cirrhosis depends on increased intrahepatic vascular resistance, which is explained by fibrosis and intrahepatic hyperresponsiveness to vasoconstrictors. Both are caused by activation and proliferation of hepatic stellate cells (HSCs). Portal hypertension of cirrhotic rats can be reduced by the multikinase inhibitor sorafenib, due to a reduction of intrahepatic vascular resistance. Therefore, the hepatic effects of sorafenib require further understanding. Here, we investigated hepatic and HSC-specific sorafenib effects in cirrhotic rats. Animal models of bile duct ligation-induced secondary biliary cirrhosis in rats were studied. The rats were treated with sorafenib (60 mg/kg/day) for 1 week, starting after established cirrhosis. Histological evaluation was carried out using hemalaun and eosin (HE) staining. Apoptosis was studied by PARP cleavage, colorimetric caspase-3 assay, and electrophoretic DNA detection. HSC activation was studied by hepatic Sirius red and immunohistochemical aSMA (a-smooth muscle actin) staining, and by in vitro experiments with culture-activated primary HSCs. Biochemical serum parameters suggested the occurrence of sorafenib-induced liver damage. HE staining revealed histological changes in livers of sham-operated and bile duct-ligated (BDL) rats in response to sorafenib, which were different in both groups. In BDL rats and isolated HSCs, the treatment with sorafenib reduced hepatic aSMA and procollagen-1a mRNA expression. As shown by immunohistochemical staining, perisinusoidal aSMA expression was reduced by sorafenib in BDL rats. This was associated with reduced perisinusoidal deposition of extracellular matrix, as revealed by Sirius red staining. Although no change in PARP cleavage and only a minor increase in hepatic caspase-3 activity were detected in BDL rats in response to sorafenib, livers of sorafenib-treated BDL rats contained small DNA fragments, which were not observed in untreated BDL rats. In conclusion, sorafenib treatment reduces the number of activated HSCs in cirrhotic livers. This leads to the decrease in intrahepatic vascular resistance, but also to liver damage in the dosage we used. Therefore, any translation to portal hypertensive patients who may profit from sorafenib should be done with particular care.

Sorafenib and its derivative SC-1 exhibit antifibrotic effects through signal transducer and activator of transcription 3 inhibition

“…Mejias et al first reported sorafenib ameliorated portal hypertension, intrahepatic fibrosis, inflammation, and angiogenesis in a cirrhotic rat model (19). Subsequent studies demonstrated sorafenib might reduce HSC proliferation, and inhibit the synthesis of fibrogenesis-related proteins and extracellular matrix (7,20,21). Sorafenib inhibits the KLF6/angiopoietin-1/fibronectin to disrupt the LSEC-HSC interactions, affecting the matrix reconstruction and vascular remodeling (22).…”

Antiangiogenic and antifibrogenic activity of pigment epithelium-derived factor (PEDF) in bile duct-ligated portal hypertensive rats

“…It should be noted in this regard that previous attempts at targeting angiogenesis in cirrhosis by using multikinase inhibitors, such as sorafenib or imatinib, were successful in rats,5 6 but have little translational potential due to the many adverse effects that these agents may have by interfering with physiological angiogenesis 8 9. In fact, it has been previously reported that sorafenib at doses of 60 mg/kg induced biochemical and histological signs of liver injury, especially in cirrhotic rats 28. Our studies, therefore, provide in vivo evidence suggesting that exogenous PEDF supplementation may be a promising and plausible therapeutic modality for treatment and prevention of PH and chronic liver disease, at least in an early clinical setting.…”

Sorafenib treatment improves hepatopulmonary syndrome in rats with biliary cirrhosis

“…Some adverse effects of anti-angiogenesis therapy in cirrhotic patients have been reported, including interstitial pneumonitis and variceal bleeding [38,39]. In addition, Henneberg et al demonstrated that 7 days of sorafenib treatment [60 mg·(kg of body weight) − 1 ·day − 1 ] caused impaired liver biochemistry and damaged hepatic histology in CBDL rats [40]. They found that sorafenib-induced hepatic injury in both CBDL and sham-operated rats, but worse in CBDL rats, which implicated that high-dose sorafenib treatment may have direct hepatic toxicity in cirrhotic rats [40].…”

“…In addition, Henneberg et al demonstrated that 7 days of sorafenib treatment [60 mg·(kg of body weight) − 1 ·day − 1 ] caused impaired liver biochemistry and damaged hepatic histology in CBDL rats [40]. They found that sorafenib-induced hepatic injury in both CBDL and sham-operated rats, but worse in CBDL rats, which implicated that high-dose sorafenib treatment may have direct hepatic toxicity in cirrhotic rats [40]. It is noteworthy that the regimen of 14 days of sorafenib treatment [10 mg·(kg of body weight) − 1 ·day − 1 in the present study] elevates the plasma levels of AST and ALT in sham-operated rats.…”