ABSTRACT
Autophagy, an evolutionarily conserved process by which components of the cell are degraded in lysosomes, may facilitate survival of cancer cells under stress conditions. 8-Azaguanine (8-AG), an inhibitor of purine nucleotide biosynthesis, shows antineoplastic activity in multiple tumor cells. However, chemoresistance has restricted its development as an anticancer agent, and the mechanism of 8-AG resistance is not fully understood. We report here that 8-AG induces a protective autophagy to eliminate its cytotoxicity, and inhibition of autophagy increases cellular sensitivity of cancer cells to 8-AG treatment. Using HepG2 or SMMC-7721 hepatic cancer cell lines, we found that 8-AG inhibited cell viability and induced intrinsic apoptosis, accompanied by the up-regulation of the pro-apoptotic protein BimS, one of Bim (also known as BCL-2-like protein 11, BCL2L11) isoforms. Furthermore, 8-AG treatment enhanced the autophagy flux by promoting the dephosphorylation and activation of Unc-51-like autophagy activating kinase 1 (ULK1) via Akt/mTORC1 (mammalian target of rapamycin complex 1) signaling inhibition. Depletion of autophagy-related gene 7 (ATG7) markedly enhanced the level of BimS, and promoted cell death in response to 8-AG. 8-AG in combination with autophagy inhibitor chloroquine (CQ) or bafilomycin A1 (Baf A1) promoted the 8-AG-induced apoptosis in hepatic cancer cells. Altogether, these findings suggest that autophagy promotes chemoresistance of cancer cells for 8-AG, and blocking autophagy increases cellular sensitivity of cancer cells to 8-AG treatment.
ABSTRACT
Objective:To investigate the role and mechanism of IL-38 in inhibiting osteoporosis.Methods:A total of 138 cases of patients with osteoporosis in our hospital from June 2014 to December 2016 were recruited.Another 120 cases of fracture surgery patients without osteoporosis were selected as control.Serum levels of IL-38 in different groups were determined using a commercially available sandwich ELISA (Enzyme-Linked ImmunoSorbent Assay).Construction of IL-38-C57BL/6J transgenic mice,the wild type and IL-38 transgenic mice were set to sham operation group (Sham),operation group (ovariectomy,group OVX) respectively.After 8 weeks of the operation,the serum level of alkaline phosphatase(ALP),calcium and phosphorus were detected.The bilateral femur and spine of mice were collected after sacrifice,the morphology and structure of the femur were analyzed,and the bone density was measured by bone density meter.The bone marrow stromal cells(BMSCs) were isolated and the invitro proliferation ability of BMSCs were meas-ured.Western blot were used to detect the phosphorylation level of PI3K,Akt,GSK3β and NFATc1 in BMSCs.After transfection of IL-38 into mouse osteoblast MC3T3-E1 cell,the phosphorylation level of PI3K,Akt,GSK3β and NFATc1 were detected by Western blot.Apoptosis of MC3T3-E1 cells were detected by flow cytometry.Results:The serum level of IL-38 in patients with osteoporosis were significant lower than control group(P<0.05).The serum level of estrogen,calcium and phosphorus in OVX group of wild type and IL-38 transgenic mice were significant lower than the sham operation group(P<0.05),while the level of ALP was significant higher than sham operation group (P<0.05),but the serum level of calcium and phosphorus in OVX group of IL-38 transgenic mice were significant higher than wild type mice(P<0.05).The pathological section of femur and spine BMD showed that the bone tissue in wild type mice and IL-38 transgenic mice in OVX group were damaged and the bone density decreased significantly,but IL-38 transgenic mice was significant better than wild type mice (P<0.05).The proliferation ability of BMSCs in OVX group of IL-38 transgenic mice was significant higher than wild type mice (P<0.05).The phosphorylation level of PI3K,Akt and NFATc1 in OVX group of IL-38 transgenic mice were significant lower than wild type mice(P<0.05),while the phosphorylation level of GSK3β was significant higher than wild type mice (P<0.05).After transfection of IL-38 into MC3T3-E1 cell,the phosphorylation level of PI3K,Akt and NFATc1 were significant decreased (P<0.05),while the phosphorylation level of GSK3β was significant increased (P<0.05).Flow cytometry assay showed that IL-38 transfection significant decreased the apoptosis of MC3T3-E1 cells(P<0.05).Conclusion:The serum level of IL-38 in patients with osteoporosis is decreased significantly.IL-38 may inhibit the proliferation of BMSCs and inhibit the apoptosis of osteoblasts by regulating the PI3K/Akt/GSK3β/NFATc1 signaling pathway.
ABSTRACT
It is investigated that the hepatotoxicity of Polygonum multiflorum (PM)was attenuated by its processed products of nine times steaming and nine times sunning(RPM)based on immunological stress-mediated animal model by using metabolomics method. Sprague-Dawley(SD)rats were intragastrically administered with(5.4 g crude drug per kg body weight)of 50% alcohol extracts of PM and its processed products of nine times steaming and nine times sunning respectively or co-treated with non-toxic dose of lipopolysaccharide(LPS, 2.8 mg·kg-1)via tail vein injection. The plasma alanine aminotransferase(ALT)and aspartate aminotransferase(AST)activities were assayed and the isolated livers were evaluated for histopathological changes. Global metabolomics profiling, multivariate analysis and data base searching were performed to discover common differential metabolites for idiosyncratic liver injury. The results showed that co-treatment with non-toxic dose of LPS and PM could result in significant liver injury, indicated by the elevation of plasma ALT and AST activities, as well as obvious liver histologic damage; whereas RPM failed to induce detectable liver injury. Furthermore, 10 potential metabolomics biomarkers that differentially expressed in LPS/PM group compared with LPS/RPM without liver injury were identified by untargeted metabolomics, mainly involved ten pathways: sphingolipid metabolism, linoleic acid metabolism, taurine and hypotaurine metabolism, steroid hormone biosynthesis, galactose metabolism, steroid biosynthesis, metabolism of xenobiotics by cytochrome P450, pyrimidine metabolism, biosynthesis of unsaturated fatty acids, primary bile acid biosynthesis. This work illustrated the idiosyncratic hepatotoxicity of heshouwu and provided a metabolomic insight into diosyncratic liver injury of PM and RPM.
ABSTRACT
In this study, the three dimensional(3D)organoid culture system was established by liquid overlay method, and applied as an effective model to evaluate the hepatic injury of susceptible compounds in Polygonum multiflorum Thunb. Compared with the ordinary two dimensional(2D)culture of liver cells, the albumin expression of L02 cells and HepG2 cells were increased by 2.5 and 6.7 times in the 3D organoid culture system, respectively. After the cultivation of 21 days, urea generation levels of 3D culture were increased by 8.3 and 15.5 times. More importantly, HepG2 cells were more suitable to development of organoids than L02 cells. The gene expressions of phase I and II drug metabolism enzymes of HepG2 cells cultured as 3D organoids were significantly increased than that in 2D culture, such as the fold changes of CYP2C9 was up to 381.9, CYP3A4 to 87.0, CYP2D6 to 312.6. In addition, drug transporter relative genes were also up-regulated. The results demonstrated that the liver synthesis and metabolic function of the 3D model were better than that of the 2D cultured hepatocytes. The results of hepatotoxicity evaluation showed this developed model can be used to assess the hepatotoxicity of acetaminophen and other positive control drugs, which were considered with defined hepatotoxicity. On the 3D culture model, the IC50 value of repeated drug dose administration was significantly lower than that of single dose administration. However, the IC50 of 2,3,5,4'-tetrahydroxy-cis-stilbene-2-O-β-glucoside(cis-SG), which is the susceptible compound in Polygonum multiflorum Thunb., could not be detected in 2D cultured model. With the treatment of a single dose administration in organ 3D culture model, the IC50 of cis-SG was 1.9 times than that of cyclosporine A, and the IC50 of 2,3,5,4'-tetrahydroxy-trans-stilbene-2-O-β-glucoside(trans-SG)was 4.1 times than cis-SG. The hepatotoxicity results of cis-SG and trans-SG on the 3D cultures were similar to in vivo toxicity results obtained in previous work. On organ 3D culture model, the IC50 of cis-SG with repeat of administration decreased compared with that with single dose administration, suggesting that long-term medication may increase the risk of liver injury. In summary, the 3D organoid culture system can be used for a long period to preserve the capacity of liver synthesis and metabolism. The organoids were a model suitable for evaluation of mechanism of the drugs with low toxicity.
ABSTRACT
This study was designed to investigate the correlation between idiosyncratic liver injury and content of cis-2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside(cis-SG)in radix Polygoni multiflori Preparata(RPMP). In order to compare the effect of hepatotoxicity of different cis-SG contents in RPMP, rats were administered with 50% alcohol extracts of RPMP(7.56 g·kg-1, via intragastric administration)alone or co-treated with lipopolysaccharide(LPS, 2.8 mg·kg-1, via tail vein injection). The results showed that no significant alterations of plasma ALT and AST activities were observed in the normal rats. In the LPS treated rats, the group without light treatment and the group with 0.10% cis-SG after light treatment did not exhibit obvious injury in liver. The group with 0.35% cis-SG after light treatment and the group with 0.70% cis-SG after light treatment showed significant increases in ALT, AST, TNF-α, IL-6, NF-κB p65 and apoptosis rate(P < 0.05), causing pathological changes in the liver tissue. Through the content analysis of drug in patients with liver injury, we found that the content of cis-SG(> 0.40%)was generally higher than that of pieces collected from different origins(< 0.10%). The comparative analysis of experiments and clinical data showed that there was a relationship between the content of cis-SG and idiosyncratic liver injury. In order to reduce the risk of clinical medication, the content of cis-SG of 0.10% should be a limit of quality control in the production processing of Polygonum multiflorum.