TXNIP knockdown alleviates hepatocyte ischemia reperfusion injury through preventing p38/JNK pathway activation.

Hepatic ischemia and reperfusion (I/R) injury is a major cause of liver damage during liver transplantation, resection surgery, shock, and trauma. It has been reported that TXNIP expression was upregulated in a rat model of hepatic I/R injury. However, the role of TXNIP in the hepatic I/R injury is little known. In our study, we investigated the biological role of TXNIP and its potential molecular mechanism in the human hepatic cell line (HL7702 cells). Using oxygen-glucose deprivation and reoxygenation (OGD/R) to create a cell model of hepatic I/R injury, we found that the mRNA and protein expression levels of TXNIP were upregulated in HL7702 cells exposed to OGD/R. TXNIP overexpression remarkably promoted OGD/R-induced cell apoptosis and lactate dehydrogenase (LDH) release, both of which were significantly decreased by TXNIP knockdown. The production of malondialdehyde (MDA) was also increased by TXNIP overexpression, but was reduced by TXNIP knockdown. Moreover, TXNIP overexpression significantly upregulated the phosphorylation of p38 and JNK, which was remarkably inhibited by TXNIP knockdown. Additionally, p38-specific inhibitor SB203580 abrogated the effect of TXNIP overexpression on OGD/R-induced cell injury. Taken together, these results indicated that TXNIP knockdown alleviated hepatocyte I/R injury through preventing p38/JNK pathway activation. Thus, TXNIP might offer a novel potential therapeutic target for the treatment of hepatic I/R injury.

Actin Disorganization Plays a Vital Role in Impaired Embryonic Development of In Vitro-Produced Mouse Preimplantation Embryos.

Assisted reproductive technology (ART) is being increasingly applied to overcome infertility. However, the in vitro production process, the main procedure of ART, can lead to aberrant embryonic development and health-related problems in offspring. Understanding the mechanisms underlying the ART-induced side effects is important to improve the ART process. In this study, we carried out comparative transcriptome profiling between in vivo- (IVO) and in vitro- produced (IVP) mouse blastocysts. Our results suggested that aberrant actin organization might be a major factor contributing to the impaired development of IVP embryos. To test this, we examined the effect of actin disorganization on the development of IVP preimplantation embryos. Specific disruption of actin organization by cytochalasin B (CB) indicated that well-organized actin is essential for in vitro embryonic development. Supplementing the culture medium with 10(-9) M melatonin, a cytoskeletal modulator in adult somatic cells, significantly reversed the disrupted expression patterns of genes related to actin organization, including Arhgef2, Bcl2, Coro2b, Flnc, and Palld. Immunofluorescence analysis showed that melatonin treatment of IVP embryos significantly improved the distribution and organization of actin filaments (F-actin) from the 8-cell stage onwards. More importantly, we found that melatonin alleviated the CB-mediated aberrant F-actin distribution and organization and rescued CB-induced impaired embryonic development. This is the first study to indicate that actin disorganization is implicated in impaired development of IVP embryos during the preimplantation stage. We also demonstrated that improving actin organization is a promising strategy to optimize existing IVP systems.

Matrine inhibits the invasive properties of human osteosarcoma cells by downregulating the ERK-NF-κB pathway.

Matrine has been used in anti-inflammatory and anticancer therapies for a long time. However, the antimetastatic effect and molecular mechanism(s) of matrine on osteosarcoma are still unclear. Therefore, the aim of this study was to assess the effects of matrine and related mechanism(s) on osteosarcoma cells. In the study, we found that matrine inhibited the proliferation of osteosarcoma cells in vivo and in vitro and inhibited tumor cell metastasis in vitro at cytotoxic doses. Matrine also decreased the expression of the matrix metalloproteinases-2 and 9, decreased p50 and p65 nuclear translocation, and decreased the phosphorylated level of I-κ-B (IκB)-ß. In addition, matrine reduced the phosphorylated levels of extracellular signal-regulated kinase 1/2 proteins, which regulate the invasion of poorly differentiated cancer cells. Finally, when U2OS cells were grown as xenografts in nude mice, intragastric administration of matrine induced a significant dose-dependent decrease in tumor growth. These results show the anticancer properties of matrine, which include the inhibition of invasion and proliferation of human osteosarcoma cells.

[Analysis of microorganism species diversity in plant intercropping models in a wetland system constructed for treatment of municipal sewage].

The selective culture method and PCR-DGGE technology were applied to analyze the number and the biodiversity of microorganism species in cells with plant intercropping models and without plants in different seasons in a wetland system constructed for treatment of municipal sewage. The results showed that the numbers of microorganisms were considerably larger in the cells with plant intercropping models than those without plants, while the number of microorganisms was apparently larger in summer than that in winter in all treatments. Along the three-sequenced treatment cells with plant intercropping models a "low-high-low" changing trend in the numbers of microorganisms in summer. The UPGMA cluster analysis showed that the treatments in the same season were clustered in the same branch except for a few samples in winter and the biodiversity index was consistently higher in summer than that in winter. Five different sequences (DF1-DF5) were obtained through BLAST analysis and retrieval. The closest known origin groups were located as Escherichia coli, Citrobacter sp., Proteus sp., Klebsiella oxytoca, and Burkholderia sp. respectively. The BLASTX comparison test showed that DF1 closely related to the activities of the Mycobacterium bacillus and the Bacillus amyloliquefaciens, DF2 functioned as a conservative potential ATP binding protein, DF3 related to the activities of the Bacillus cereus spore, DF4 was involved in catabolism metabolism of microorganism and DF5 played an important role in decomposition of organic matters.

[Temporary acid exposure promotes normal human esophageal epithelial cell proliferation and ERK expression in vitro].

OBJECTIVE: To observe the effects of temporary acid exposure on cell proliferation and extracellular signal-regulated protein kinase (ERK) activity in normal human esophageal epithelial cells in vitro. METHODS: Normal human esophageal epithelial cells cultured in vitro were exposed to acidic media (pH 4.0-6.5) for 3 to 60 min, and the control cells were cultured at pH 7.3. MTT assay and flow cytometry were employed for cell proliferation assessment. The expression of phosphorylated ERK1/2 protein was determined by immunoblotting. RESULTS: Esophageal epithelial cells with acid exposure for 3 min exhibited a significant increase in cell proliferation, increased number of cells in S phase and enhanced expression of phosphorylated ERK1/2 protein. Acid exposure of the esophageal epithelial cells exceeding 6 min resulted in depressed proliferation and decreased S-phase cells, and cell proliferation induced by acid exposure was abolished by pretreatment with U0126. CONCLUSION: Temporary acid stimulus increases cell proliferation of normal human esophageal epithelial cells in vitro by activating the ERK pathway.

Influence of acid and bile acid on ERK activity, PPARgamma expression and cell proliferation in normal human esophageal epithelial cells.

AIM: To observe the effects of acid and bile acid exposure on cell proliferation and the expression of extracellular signal-regulated protein kinase (ERK) and peroxisome proliferator-activated receptor gamma (PPARgamma) in normal human esophageal epithelial cells in vitro. METHODS: In vitro cultured normal human esophageal epithelial cells were exposed to acidic media (pH 4.0-6.5), media containing different bile acid (250 mumol/L), media containing acid and bile acid, respectively. Cell proliferation was assessed using MTT and flow cytometry. The expressions of phosphorylated ERK(1/2) and PPARgamma protein were determined by the immunoblotting technique. RESULTS: Acid-exposed (3 min) esophageal cells exhibited a significant increase in proliferation ratio, S phase of the cell cycle (P<0.05) and the level of phosphorylated ERK(1/2) protein. When the acid-exposure period exceeded 6 min, we observed a decrease in proliferation ratio and S phase of the cell cycle, with an increased apoptosis ratio (P<0.05). Bile acid exposure (3-12 min) also produced an increase in proliferation ratio, S phase of the cell cycle (P<0.05) and phosphorylated ERK(1/2) expression. On the contrary, deoxycholic acid (DCA) exposure (>20 min) decreased proliferation ratio. Compared with bile acid exposure (pH 7.4), bile acid exposure (pH 6.5, 4) significantly decreased proliferation ratio (P<0.05). There was no expression of PPARgamma in normal human esophageal epithelial cells. CONCLUSION: The rapid stimuli of acid or bile acid increase proliferation in normal human esophageal epithelial cells by activating the ERK pathway.

Portal hypertensive gastropathy and its interrelated factors.

OBJECTIVE: To investigate the influences of helicobacter pylori (Hp) infection, liver function, gastroesophageal varicosity, esophageal varicosity ligation (EVL), and esophageal varicosity sclerotherapy (EVS) on patients with portal hypertensive gastropathy (PHG). METHODS: Fourty-seven patients with liver cirrhosis included 34 patients with PHG and 13 patients without PHG. Liver function, Hp infection, and gastroesophageal varicosity were investigated clinically in all patients, and gastroscopy was made again in patients with EVL 1-2 months after operation to observe the changes of PHG. RESULTS: The rate of Hp infection was lower in patients with liver cirrhosis than in controls. There was no relationship between Hp infection and PHG. The patients with gastroesophageal varicosity had a high incidence of PHG. CONCLUSIONS: Despite no relationship between Hp infection and PHG, liver dysfunction can affect and promote PHG. Gastroesophageal varicosity may be closely related to PHG, but their degrees are not related. PHG can be caused or promoted by EVL.