Pegylated Interferon-α Modulates Liver Concentrations of Activin-A and Its Related Proteins in Normal Wistar Rat

Activins and their related proteins in colon carcinogenesis: insights from early and advanced azoxymethane rat models of colon cancer

BACKGROUND

Activin-A may exert pro- or anti-tumorigenic activities depending on cellular context. However, little is known about its role, or the other mature activin proteins, in colorectal carcinoma (CRC). This study measured the expression of activin βA- & βB-subunits, activin type IIA & IIB receptors, smads 2/3/4/6/7 and follistatin in CRC induced by azoxymethane (AOM) in rats. The results were compared with controls and disseminated according to the characteristics of histopathological lesions.

METHODS

Eighty male Wistar rats were allocated into 20 controls and the remaining were equally divided between short 'S-AOM' (15 weeks) and long 'L-AOM' (35 weeks) groups following injecting AOM for 2 weeks. Subsequent to gross and histopathological examinations and digital image analysis, the expression of all molecules was measured by immunohistochemistry and quantitative RT-PCR. Activin-A, activin-B, activin-AB and follistatin were measured by ELISA in serum and colon tissue homogenates.

RESULTS

Colonic pre-neoplastic and cancerous lesions were identified in both AOM groups and their numbers and sizes were significantly (P < 0.05) greater in the L-AOM group. All the molecules were expressed in normal colonic epithelial cells. There was a significantly (P < 0.05) greater expression of βA-subunit, IIB receptor and follistatin in both pre-neoplastic and cancerous tissues. Oppositely, a significant (P < 0.05) decrease in the remaining molecules was detected in both AOM groups. Metastatic lesions were only observed within the L-AOM group and were associated with the most significant alterations of all molecules. Significantly higher concentrations of activin-A and follistatin and lower activin-AB were also detected in both groups of AOM. Tissue and serum concentrations of activin-A and follistatin correlated positively, while tissue activin-AB inversely, and significantly with the numbers and sizes of colonic lesions.

CONCLUSIONS

Normal rat colon epithelial cells are capable of synthesising, controlling as well as responding to activins in a paracrine/autocrine manner. Colonic activin systems are pathologically altered during tumorigenesis and appear to be time and lesion-dependent. Activins could also be potential sensitive markers and/or molecular targets for the diagnosis and/or treatment of CRC. Further studies are required to illustrate the clinical value of activins and their related proteins in colon cancer.

The fibrolytic potentials of vitamin D and thymoquinone remedial therapies: insights from liver fibrosis established by CCl4 in rats

BACKGROUND

Vitamin D (VitD) and thymoquinone (TQ) are nutraceutical agents with well-known immunomodulatory and hepatoprotective properties. This study measured whether VitD and TQ, individually or combined, could have direct fibrolytic activities and/or enhanced performance during remedial treatment of liver fibrosis established by CCl4 in rats.

METHODS

Eighty five male Wistar rats were used as 10 negative controls (NC) and the remainders were distributed equally into 5 groups: short (S-PC) and long (L-PC) positive controls, TQ, VitD and VitD/TQ groups. CCl4 was injected for 7 weeks followed by a week of no intervention. TQ and/or VitD were given orally (3 days/week) from week 9 and euthanasia was at week 17 for all groups except the S-PC was at week 9. Following histopathological and digital image analyses, TGF-β1, IL-6, IL-10, IL-22 and MMP-9 were measured by ELISA in liver homogenates while the corresponding cytokine receptors were measured by immunohistochemistry. The mRNA expressions of all molecules were measured by quantitative RT-PCR.

RESULTS

Fibrosis was evident in both PC-groups and was significantly more advanced in the L-PC than S-PC, reaching to cirrhosis. The concentrations of TGF-β1, IL-6, IL-22 and their receptors were significantly higher (P < 0.05) simultaneously with significantly lower (P < 0.05) concentrations of MMP-9, IL-10 and IL-10 receptors in the S-PC and L-PC than the NC-group. TQ and VitD monotherapies showed significantly less fibrosis than L-PC but were similar to S-PC. Both remedial monotherapies also resulted in significant decreases of TGF-β1, IL-6, IL-22 and their receptors together with significant increases of MMP-9 and IL-10 system compared with S-PC and L-PC groups. Interestingly, dual therapy resulted in the most significant improvement in fibrosis score and index, yet was significantly higher (P < 0.05) than the NC-group, and concurred with the utmost significant restorations of all candidate genes and proteins.

CONCLUSIONS

VitD and TQ exhibited comparable anti-fibrogenic effects and modulated several pro- and anti-fibrotic mediators. Additionally, VitD/TQ dual therapy alleviated the previously established liver fibrosis simultaneously with significantly enhanced actions at the molecular level. More studies are required to explorer the therapeutic value of TQ and VitD against liver fibrosis in human.