Genetic and pharmacological inhibition of XBP1 protects against APAP hepatotoxicity through the activation of autophagy

Acetaminophen (APAP) hepatotoxicity induces endoplasmic reticulum (ER) stress which triggers the unfolded protein response (UPR) in hepatocytes. However, the mechanisms underlying ER stress remain poorly understood, thus reducing the options for exploring new pharmacological therapies for patients with hyperacute liver injury. Eight-to-twelve-week-old C57BL/6J Xbp1-floxed (Xbp1f/f) and hepatocyte-specific knockout Xbp1 mice (Xbp1?hepa) were challenged with either high dose APAP [500?mg/kg] and sacrificed at early (1-2?h) and late (24?h) stages of hepatotoxicity. Histopathological examination of livers, immunofluorescence and immunohistochemistry, Western blot, real time (RT)-qPCR studies and transmission electron microscopy (TEM) were performed. Pharmacological inhibition of XBP1 using pre-treatment with STF-083010 [STF, 75?mg/kg] and autophagy induction with Rapamycin [RAPA, 8?mg/kg] or blockade with Chloroquine [CQ, 60?mg/kg] was also undertaken in vivo. Cytoplasmic expression of XBP1 coincided with severity of human and murine hyperacute liver injury. Transcriptional and translational activation of the UPR and sustained activation of JNK1/2 were major events in APAP hepatotoxicity, both in a human hepatocytic cell line and in a preclinical model. Xbp1?hepa livers showed decreased UPR and JNK1/2 activation but enhanced autophagy in response to high dose APAP. Additionally, blockade of XBP1 splicing by STF, mitigated APAP-induced liver injury and without non-specific off-target effects (e.g., CYP2E1 activity). Furthermore, enhanced autophagy might be responsible for modulating CYP2E1 activity in Xbp1?hepa animals. Genetic and pharmacological inhibition of Xbp1 specifically in hepatocytes ameliorated APAP-induced liver injury by enhancing autophagy and decreasing CYP2E1 expression. These findings provide the basis for the therapeutic restoration of ER stress and/or induction of autophagy in patients with hyperacute liver injury.© 2022. The Author(s)

COMPARISON OF THE METABOLIC EFFECTS OF CARVEDILOL AND METОPROLOL IN HYPERTENSIVE PATIENTS WITH OVERWEIGHT AND OBESITY. THE CAMELLIA TRIAL

Aim. To compare two therapies based on carvedilol or metoprolol in hypertensive patients with overweight and obesity.Material and methods. 320 patients with arterial hypertension (1-2 degree) were involved in the study. 160 patients received carvedilol and 160 patients – metoprolol. Both randomized groups were comparable on the main clinical characteristics.Results. By the end of the study both systolic and diastolic blood pressure (SBP, DBP) reduced in both groups р&lt;0,0001. There were not differences of antihypertensive effect between investigated drugs (р=0,88 for SBP and р=0,61 for DBP). By the end of the study body mass index decreased by 0,52±0,10 kg/m2 (р&lt;0,0001) in carvedilol group and by 0,26±0,10kg/m2 (р&lt;0,01) in metoprolol group. Carvedilol in comparison with metoprolol had more positive effects on glucose (р&lt;0,01) and lipid blood levels. By the end of the study urine acid blood level reduction was observed in carvedilol group (-16,6 μmol/l) while an increasing tendency - in metoprolol group. Carvedilol did not have negative effect on serum potassium and creatinine levels. Adverse effects rate was 6,3% in carvedilol group and 3,8% - in metoprolol group.Conclusion. The results of open, randomized CAMELLIA trial confirmed antihypertensive effect and good tolerability of carvedilol in common clinical practice as well as demonstrated some its advantages in patients with metabolic syndrome. Carvedilol has positive metabolic effects on lipid, glucose and uric acid levels. Carvedilol therapy is more preferable in patients with arterial hypertension and metabolic risk factors.</p

CCN3/NOV small interfering RNA enhances fibrogenic gene expression in primary hepatic stellate cells and cirrhotic fat storing cell line CFSC

Nephroblastoma overexpressed gene encodes a matricellular protein (CCN3/NOV) of the CCN family, comprising CCN1 (CYR61), CCN2 (CTGF), CCN4 (WISP-1), CCN5 (WISP-2), and CCN6 (WISP-3). CCN proteins are involved in the regulation of mitosis, adhesion, apoptosis, extracellular matrix production, growth arrest and migration in multiple cell types. Compared to CCN2/CTGF, known as a profibrotic protein, the biological role of CCN3/NOV in liver fibrosis remains obscure. In this study we showed ccn3/nov mRNA to increase dramatically following hepatic stellate cell activation, reaching peak levels in fully transdifferentiated myofibroblasts. In models of experimental hepatic fibrosis, CCN3/NOV increased significantly at the mRNA and protein levels. CCN3/NOV was found mainly in non-parenchymal cells along the areas of tissue damage and repair. In the bile-duct ligation model, CCN3/NOV was localized mainly along portal tracts, while the repeated application of carbon tetrachloride resulted in CCN3/NOV expression mainly in the centrilobular areas. In contrast to CCN2/CTGF, the profibrotic cytokines platelet-derived growth factor-B and -D as well as transforming growth factor-β suppressed CCN3/NOV expression. In vitro, CCN3/NOV siRNA attenuated migration in the cirrhotic fat storing cell line CFSC well in line with in vivo findings that various types of cells expressing CCN3/NOV migrate into the area of tissue damage and regeneration. The suppression of CCN3/NOV enhanced expression of profibrotic marker proteins, such as α-smooth muscle actin, collagen type I, fibronectin, CCN2/CTGF and TIMP-1 in primary rat hepatic stellate cells and in CFSC. We further found that adenoviral overexpression of CCN2/CTGF suppressed CCN3/NOV expression, while the overexpression of CCN3/NOV as well as the suppression of CCN3/NOV by targeting siRNAs both resulted in enhanced CCN2/CTGF expression. These results indicate the complexity of CCN actions that are far beyond the classic Yin/Yang interplay