Carvedilol improves liver cirrhosis in rats by inhibiting hepatic stellate cell activation, proliferation, invasion and collagen synthesis

Effects of carvedilol on human prostate tissue contractility and stromal cell growth pointing to potential clinical implications

BACKGROUND

Apart from antagonizing ß-adrenoceptors, carvedilol antagonizes vascular α1-adrenoceptors and activates G protein-independent signaling. Even though it is a commonly used antihypertensive and α1-adrenoceptors are essential for the treatment of voiding symptoms in benign prostatic hyperplasia, its actions in the human prostate are still unknown. Here, we examined carvedilol effects on contractions of human prostate tissues, and on stromal cell growth.

METHODS

Contractions of prostate tissues from radical prostatectomy were induced by electric field stimulation (EFS) or α1-agonists. Growth-related functions were examined in cultured stromal cells.

RESULTS

Concentration-response curves for phenylephrine, methoxamine and noradrenaline were right shifted by carvedilol (0.1-10 µM), around half a magnitude with 100 nM, half to one magnitude with 1 µM, and two magnitudes with 10 µM. Right shifts were reflected by increased EC50 values for agonists, with unchanged Emax values. EFS-induced contractions were reduced by 21-54% with 0.01-1 µM carvedilol, and by 94% by 10 µM. Colony numbers of stromal cells were increased by 500 nM, but reduced by 1-10 µM carvedilol, while all concentrations reduced colony size. Decreases in viability were time-dependent with 0.1-0.3 µM, but complete with 10 µM. Proliferation was slightly increased by 0.1-0.5 µM, but reduced with 1-10 µM.

CONCLUSIONS

Carvedilol antagonizes α1-adrenoceptors in the human prostate, starting with concentrations in ranges of known plasma levels. In vitro, effect sizes resemble those of α1-blockers used for the treatment of voiding symptoms, which requires concentrations beyond plasma levels. Bidirectional and dynamic effects on the growth of stromal cells may be attributed to "biased agonism".

Protective Effect of Curcumin against Doxazosin- and Carvedilol-Induced Oxidative Stress in HepG2 Cells

Doxazosin and carvedilol have been evaluated as an alternative treatment against chronic liver lesions and for their possible role during the regeneration of damage caused by liver fibrosis in a hamster model. However, these drugs have been reported to induce morphological changes in hepatocytes, affecting the recovery of liver parenchyma. The effects of these α/𝛽 adrenoblockers on the viability of hepatocytes are unknown. Herein, we demonstrate the protective effect of curcumin against the possible side effects of doxazosin and carvedilol, drugs with proven antifibrotic activity. After pretreatment with 1 μM curcumin for 1 h, HepG2 cells were exposed to 0.1–25 μM doxazosin or carvedilol for 24, 48, and 72 h. Cell viability was assessed using the MTT assay and SYTOX green staining. Morphological changes were detected using the hematoxylin and eosin (H&E) staining and scanning electron microscopy (SEM). An expression of apoptotic and oxidative stress markers was analyzed using reverse transcription-quantitative PCR (RT-qPCR). The results indicate that doxazosin decreases cell viability in a time- and dose-dependent manner, whereas carvedilol increases cell proliferation; however, curcumin increases or maintains cell viability. SEM and H&E staining provided evidence that doxazosin and carvedilol induced morphological changes in HepG2 cells, and curcumin protected against these effects, maintaining the morphology in 90% of treated cells. Furthermore, curcumin positively regulated the expression of Nrf2, HO-1, and SOD1 mRNAs in cells treated with 0.1 and 0.5 μM doxazosin. Moreover, the Bcl-2/Bax ratio was higher in cells that were treated with curcumin before doxazosin or carvedilol. The present study demonstrates that curcumin controls doxazosin- and carvedilol-induced cytotoxicity and morphological changes in HepG2 cells possibly by overexpression of Nrf2.

Doxazosin Attenuates Liver Fibrosis by Inhibiting Autophagy in Hepatic Stellate Cells via Activation of the PI3K/Akt/mTOR Signaling Pathway

Purpose

To investigate the effect of doxazosin on autophagy and the activation of hepatic stellate cells (HSCs) in vivo and in vitro and determine the underlying mechanism.

Methods

In vivo, a mouse liver fibrosis model was induced by the intraperitoneal injection of carbon tetrachloride (CCl₄). Doxazosin was administered at doses of 2.5, 5 and 10 mg/(kg*day) by gavage. After 20 weeks, blood and liver tissues were collected for serological and histological analysis, respectively. Blood analysis, hematoxylin and eosin (HE) staining, Masson’s trichrome staining, immunohistochemistry and immunofluorescence staining were used to measure the extent of liver fibrosis in model and control mice. In vitro, the human HSC cell line LX-2 was cultured and treated with different doses of doxazosin for the indicated times. The effects of doxazosin on LX-2 cell proliferation and migration were examined by Cell Counting Kit-8 (CCK-8) and Transwell assays, respectively. The number of autophagosomes in LX-2 cells was observed by transmission electron microscopy (TEM). Infection with green fluorescent protein (GFP)-LC3B adenovirus, GFP-red fluorescent protein (RFP)-LC3B adenovirus and mCherry-EGFP-LC3 adeno-associated virus was performed to examine changes in autophagic flux in vitro and in vivo. Cell apoptosis was measured by flow cytometry in vitro and by TUNEL assays both in vitro and in vivo. Immunoblotting was performed to evaluate the expression levels of proteins related to fibrosis, autophagy, apoptosis, and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR).

Results

Doxazosin inhibited HSC proliferation and migration. HSC activation was attenuated by doxazosin in a concentration-dependent manner in vivo and in vitro. Doxazosin also blocked autophagic flux and induced apoptosis in HSCs. In addition, the PI3K/Akt/mTOR pathway was activated by doxazosin and regulated fibrosis, autophagy and apoptosis in HSCs.

Conclusion

The study confirmed that doxazosin could inhibit autophagy by activating the PI3K/Akt/mTOR signaling pathway and attenuate liver fibrosis.

Study on correlation between coagulation indexes and disease progression in patients with cirrhosis

OBJECTIVE

To inquire into the significance of coagulation indexes in the progression of cirrhosis.

METHODS

A total of 108 patients with cirrhosis treated in our hospital were collected as the research group (RG), and 105 healthy people who underwent concurrent physical examination were selected as the control group (CG). The coagulation indexes of all the participants were tested to determine their significance in cirrhosis progression.

RESULTS

Compared with the CG, prothrombin time (PT), activated partial thrombin time (APTT) and thrombin time (TT) in the RG were statistically prolonged, while fibrinogen (FIB) was notably decreased (P<0.05). With the increase of Child-Pugh score, PT, APTT and TT prolonged and FIB reduced gradually (P<0.05). The coagulation indexes of patients were correlated with Child-Pugh score (P<0.05). Patients in the RG showed markedly higher alanine aminotransferase (ALT), total bilirubin (TBil), total bile acid (TBA), mean platelet volume (MPV), platelet distribution width (PDW) and platelet-large cell ratio (P-LCR), with notably lower albumin (ALB), prealbumin (PA), platelet count (PLT) and coagulation factors compared with the CG. As the Child-Pugh score increased, the ALT, TBil, TBA, MPV, PDW and P-LCR gradually elevated in the RG (P<0.05), whilst coagulation factors, ALB, PLT and PA all gradually decreased (P<0.05). The value of area under the curve (AUC) of each coagulation index for early diagnosis of cirrhosis was >0.80, and the sensitivity was >80% (P<0.05).

CONCLUSION

Coagulation indexes, coagulation factors, platelet parameters and liver function all effectively reflect the level of liver injury; especially which, coagulation indexes are related to the severity of liver injury, and can provide evidence for the early diagnosis of cirrhosis patients, with clinical significance.