Effect of Hepatocyte Growth Factor-Transfected Human Umbilical Cord Mesenchymal Stem Cells on Hepatic Stellate Cells by Regulating Transforming Growth Factor-ß1/Smads Signaling Pathway.

Studies have shown that human umbilical cord mesenchymal stem cells (hUCMSCs) could ameliorate liver fibrosis (LF) through inhibiting the activation of hepatic stellate cells (HSCs). However, the specific mechanisms have not been studied clearly. The purpose of this study was to explore the possible mechanism of hepatocyte growth factor (HGF)-transfected hUCMSCs in inhibiting the proliferation and activation of HSCs-T6. The upper and lower double-cell coculture system was established among HGF-hUCMSCs, LV5-NC-hUCMSCs, hUCMSCs, and HSCs-T6 in experimental groups; HSCs-T6 were cultured alone as control group. After coculturing for 1, 2, and 3 days, results showed that HGF-transfected hUCMSCs could decrease cell viability of HSCs-T6 and promote apoptosis; inhibit their activation and reduce the expression of Collagen I, Collagen III, TGF-ß1, Smad2 and Smad3, which may be related to inhibiting the activation of TGF-ß1/Smads signaling pathway. These findings suggested that HGF-transfected hUCMSCs may be used as an alternative and novel therapeutic approach for the treatment of LF.

Exogenous melatonin alleviates hemorrhagic shock­induced hepatic ischemic injury in rats by inhibiting the NF­κB/IκBα signaling pathway.

Melatonin (MT) is an indoleamine hormone that can counteract ischemia­induced organ injury through its antioxidant effects. The aim of the present study was to investigate the protective effects of exogenous MT against hemorrhagic shock (HS)­induced hepatic ischemic injury in rats, and the role of the nuclear factor (NF)­κB signaling pathway in this process. A rat model of HS­induced hepatic ischemic injury was established. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), glutamate dehydrogenase (GDH), tumor necrosis factor (TNF)­α, interferon (IFN)­Î³, interleukin (IL)­6 and IL­1ß were measured every 6 h, and the 24­h survival rate of the rats was analyzed. All surviving rats were sacrificed after 24 h. Pathological changes in the liver and the hepatocyte apoptosis rate were observed by hematoxylin and eosin staining and TUNEL assay, respectively, and the expression levels of NF­κB p65 and NF­κB inhibitor α (IκBα) were analyzed by reverse transcription­quantitative PCR analysis and western blotting. The results demonstrated that the serum levels of ALT, AST, LDH, GDH, TNF­α, IFN­Î³, IL­6 and IL­1ß gradually increased after HS compared with those in rats subjected to a sham procedure, but this increase was attenuated by MT. Furthermore, the survival rate of the MT group was significantly higher compared with that of the HS group. The degree of pathological hepatic injury, the hepatocyte apoptosis rate, and the hepatic levels of TNF­α, IFN­Î³, IL­6 and IL­1ß were significantly decreased in the MT group compared with the HS group. In addition, the mRNA expression of NF­κB p65 was significantly decreased and the mRNA expression of IκBα was significantly increased in the MT group compared with the sham group. Furthermore, the NF­κB p65 protein levels in the MT group were significantly increased in the cytosol but decreased in the nucleus, and the IκBα protein levels were increased while those of phosphorylated IκBα were decreased compared with those in the HS group. Therefore, it may be inferred that exogenous MT alleviates HS­induced hepatic ischemic injury in rats via the inhibition of NF­κB activation and IκBα phosphorylation.

Effect of Human Umbilical Cord Mesenchymal Stem Cells Transfected with HGF on TGF-ß1/Smad Signaling Pathway in Carbon Tetrachloride-Induced Liver Fibrosis Rats.

The research on human umbilical cord-derived mesenchymal stem cells (hUCMSCs) suggests promising therapeutic strategy for ameliorating liver fibrosis and it can be an effective alternative method of orthotopic liver transplantation. Hepatocyte growth factor (HGF) is the most basic cytokine involved in the inhibition of liver fibrosis and promotion of hepatocyte proliferation and regeneration. The objective of this study was to determine the possible mechanism about how the microencapsulated hUCMSCs made by alginate-poly-lysine-alginate (A-P-A) transfected with HGF could ameliorate liver fibrosis through the TGF-ß1/Smad signaling pathway. The microencapsulated cells were divided into four groups: hUCMSC (microcapsules of hUCMSCs), HGF (microcapsules of HGF+hUCMSCs), LV5-NC (microcapsules of LV5-NC, an rLV-EF1a-EGFP+Puro control lentiviral vector+hUCMSCs), and empty microcapsule (microcapsules without any hUCMSCs), and then transplanted by intraperitoneal injection into carbon tetrachloride (CCl4)-induced liver fibrosis rats, respectively. The results showed that the fibrosis in the hUCMSC, LV5-NC, and HGF groups was significantly alleviated. Moreover, the messenger RNA (mRNA) and protein levels of collagen I, collagen III, α-SMA, TGF-ß1, Smad2, and Smad3 were significantly decreased compared with the empty microcapsule group and these indices in HGF group were more decreased compared with hUCMSC and LV5-NC groups. This study indicated that microencapsulated hUCMSCs transfected with HGF could effectively improve CCl4-induced rat liver fibrosis and the possible mechanism was closely related to the inhibition of TGF-ß1/Smad signaling pathway.

[The effects of Nrf2 gene expression induced by RU486 at different doses on A549 cell damage induced by paraquat].

OBJECTIVE: To observe the effects of Nrf2 gene expression induced by RU486 at different doses on A549 cell damage induced by paraquat (PQ). METHODS: After A549 cells transfected with Ad-RUNrf2 were treated by RU486 at the doses of 10(-10), 10(-9), 10(-8) and 10(-7) mol/L for 6 h, A549 cell cultures were exposed to 10(-3) mol/L of PQ for 48 h. Then qRT-PCR and EMSA assays were used to detect the expression of Nrf2 gene, and qRT-PCR and ELISA assays were utilized to measure the effects of Nrf2 gene on the expression of the inflammatory cytokines IL-6, IL-10 and TNF-α, apoptotic factors Caspase-3, Caspase-9 and Cytochrome C. The oxidation factors (CAT and MDA protein contents) were observed by Chemical Colorimetric Analysis. RESULTS: Nrf2 gene relative expression and protein contents increased with RU486 concentrations, and the above expression was the highest when the concentration of RU486 was 10(-7) mol/L, which was significantly higher than those in control and PQ exposure groups (P < 0.01 or P < 0.05). The relative gene expression and protein expression of IL-6 and TNF-α enhanced with the reduced concentrations of RU486, which were the lowest when RU486 concentration was 10(-7) mol/L, as compared with control and PQ exposure groups (P < 0.01 or P < 0.05), while the change of IL-10 content was the opposite. The relative expression of Caspase3, Caspase9 and Cytochrome C genes also increased with the reduced concentrations of RU486, which were the lowest when RU486 concentration was 10(-7) mol/L, as compared with control and PQ exposure groups (P < 0.01 or P < 0.05). The content of CAT enhanced with RU486 concentration, which was the highest when RU486 concentration was 10(-7) mol/L, as compared with control and PQ exposure groups (P < 0.05). But the change of MDA content was the contrary. CONCLUSION: Nrf2 expression induced by RU486 can promote the balance of oxidation-antioxidation system in A549 cells and inhibit the inflammation and apoptosis factors, which has a protective effect on A549 cell injury induced by PQ.

[In vitro construction and confirmation of adenovirus containing a mifepristone (RU486)-inducible regulation system for NRF2 gene].

OBJECTIVE: To construct an adenovirus containing a mifepristone (RU486)-inducible regulation system for NRF2 gene, express the product in H460 cell and verify whether the mentioned system can control the gene expression and assess its efficiency. METHODS: A RU486-inducible regulation system for Nrf2 gene was introduced into an adenovirus. The confirmation was performed through the LUC and Dsred genes. And the expression pattern of Nrf2 at the viral level was examined by Western blot and RT-PCR (reverse transcription-polymerase chain reaction). RESULTS: The expressions of LUC and Dsred showed a rising trend with the incremental dose of RU486. After the transfection H460 cell with Ad-RUNrf2, the results of RT-PCR and Western blot demonstrated that the expression of Nrf2 was elevated with a rising dose of RU486. After the removal of RU486, the expression of Nrf2 was reduced. CONCLUSION: The construction of an adenovirus carrying Nrf2 gene regulated by a RU486-inducible system is successful, and RU486 can adjust the cellular expression of Nrf2 factor. The LUC and the Dsred expression assumes the dosage dependence along with RU486 to increase; after the Ad-RUNrf2 infects the H460 cell, through RTPCR and Western the Blot result demonstrated that the expression of Nrf2 increases along with the RU486 dosage increases, after removing RU486, the Nrf2 expression is weaken. Showing the construction of the adenovirus carrying Nrf2 gene regulated by the mifepristone (RU486)-inducible system is successful, and RU486 can adjust the Nrf2 factor in the cell the expression.

[Effect of bromoxynil on membrane potential and respiratory control rate in isolated mitochondria from mice liver and intervention effect of NAC].

OBJECTIVE: To demonstrate the effect of bromoxynil on membrane potential and respiratory control rate (RCR) in isolate mitochondria from mice liver tissue in vitro and the intervention of NAC. METHODS: The mitochondrial was randomized to control group, bromoxynil-poisoned group and NAC-protected group. S3, S4 and RCR of the mitochondria in each sample was detected by the method of oxygen electrode. Each sample was stained by JC-1 and the changes of membrane potential of mitochondria were observed under fluorescence microscope. RESULTS: The S3 [(0.031 +/- 0.008) nano atoms oxygen x mg(-1) x min(-1)], RCR (1.820 +/- 0.181) of bromoxynil-poisoned group and RCR (4.253 +/- 0.210) of NAC-protected group were significantly lower than those of control group (P<0.01); the S4 [(0.017 +/- 0.004) nano atoms oxygen x mg(-1) x min(-1)] of NAC-protected group was significantly higher than control group (P<0.01). The S3 [(0.046 +/- 0.005) nano atoms oxygen x mg(-1) x min(-1)] and RCR of NAC-protected group were significantly higher than group B (P<0.01), S4 [(0.011 +/- 0.001) nano atoms oxygen x mg(-1) x min(-1)] of NAC-protected group was significantly lower than bromoxynil-poisoned group (P< 0.01). Observation under fluorescence microscope: the red fluorescence of mitochondria was dim or disappeared in bromoxynil-poisoned group while brightened in NAC-protected group but still dimmer than control group. CONCLUSION: In vitro, the mitochondrial RCR and the mitochondrial membrane potential are decreased after the mitochondria is incubated with bromoxynil, and NAC could improve it.