Trehalose is a nonreducing disaccharide of glucose that functions as a protectant in the stabilization of biological structures and enhances stress tolerance to abiotic stresses in organisms. We report here the expression of a Grifola frondosa trehalose synthase (TSase) gene for improving drought tolerance in sugarcane (Saccharum officinarum L.). The expression of the transgene was under the control of two tandem copies of the CaMV35S promoter and transferred into sugarcane by Agrobacterium tumefaciens EHA105. The transgenic plants accumulated high levels of trehalose, up to 8.805-12.863 mg/g fresh weight, whereas it was present at undetectable level in nontransgenic plants. It has been reported that transgenic plants transformed with Escherichia coli TPS (trehalose-6-phosphatesynthase) and/or TPP (trehalose-6-phosphate phosphatase) are severely stunted and have root morphologic alterations. Interestingly, our transgenic sugarcane plants had no obvious morphological changes and no growth inhibition in the field. Trehalose accumulation in 35S-35S:TSase plants resulted in increased drought tolerance, as shown by the drought and the drought physiological indexes, such as the rate of bound water/free water, plasma membrane permeability, malondialdehyde content, chlorophyll a and b contents, and activity of SOD and POD of the excised leaves. These results suggest that transgenic plants transformed with the TSase gene can accumulate high levels of trehalose and have enhanced tolerance to drought. FH (2006). Expression of the Grifola frondosa trehalose synthase gene and improvement of drought-tolerance in sugarcane (Saccharum officinarum L.). J Integrat Plant Biol 48(4), 453−459.
Although the influence of paternal smoking on birth defects is of great public interest, epidemiological evidence concerning this potential relationship is extremely limited. A stratified random sample of 29 hospitals in the Shanghai Municipality, China, was used to select 1012 birth defects cases and controls. Mothers of the cases and controls were interviewed in the hospitals from October 1986 to September 1987. A modest relationship between paternal smoking and overall birth defects in offspring was identified [odds ratio (OR) = 1.21, 95% confidence interval (CI): 1.01-1.45]. More markedly elevated risks were identified for anencephalus (OR = 2.1), spina bifida (OR = 1.9), pigmentary anomalies of the skin (OR = 3.3) and varus/valgus deformities of the feet (OR = 1.8). Our analysis also shows that paternal smoking is more likely to be associated with multiple rather than isolated malformations. A paternally-mediated effect of smoking on birth defects is suggested and further studies are encouraged.
Human hepatocellular carcinoma (HCC) is a highly invasive tumor with frequent distant metastasis, which is the main cause for the poor prognosis. However, the mechanisms for metastasis remain poorly investigated. MicroRNAs (miRNAs) have been implicated in HCC progression. MicroRNA-122 (miR-122) is considered as a tumor suppressor in human cancer. In the present study, miR-122 expression was found to be significantly lower in HCC than the level in normal tumor-adjacent tissues. miR-122 was clearly silenced or downregulated in five HCC cell lines (HepG2, Hep3B, MHCC97H, Huh7 and SMMC-7721) compared with normal hepatocytes (LO2). HCC patients with low expression of miR-122 had a poor 3-year survival. Univariate analysis and multivariate Cox regression analysis indicated that miR-122 is an independent prognostic factor in HCC. Downregulation of miR-122 promoted proliferation and inhibited apoptosis in Hep3B cells. We found that the public miRNA database (TargetScan) predicted that PKM2 may be a target for miR-122, and the 3'-untranslated region (3'-UTR) of PKM2 contains a highly conserved binding site for miR-122. To identify this, pre-miR-122/anti-miR-122 were respectively transfected into the Hep3B cell line. We found that miR-122 overexpression significantly reduced the level of PKM2. Moreover, knockdown of PKM2 significantly increased miR-122 inhibitor-mediated Hep3B cell apoptosis and reduced miR-122 inhibitor-mediated Hep3B cell migration and invasion. Moreover, re-expression of PKM2 partially abrogated miR-122-induced HCC cell growth arrest and apoptosis in vivo. In conclusion, miR-122 serves as a prognostic biomarker and induces apoptosis and growth arrest by downregulating PKM2 in HCC.
This study examined the association between exposure to occupational hazards and pregnancy outcomes using data from a case-control study conducted in 29 hospitals in Shanghai, China. The sample included 1,875 perinatal deaths and newborns with birth defects and the same number of controls. Information on mother's exposure to occupational radiation, chemicals, noise, and pesticides was investigated. Logistic regression analysis controlling for potential confounders showed that exposure to radiation before/during pregnancy was associated with antepartum fetal death, birth defects, small-for-gestational-age (SGA), and threatened abortion. Exposure to chemicals before/during pregnancy was associated with antepartum fetal death, early neonatal death, birth defects, preterm birth, and threatened abortion. Women exposed to pesticides during pregnancy had an increased risk of SGA and threatened abortion. Exposure to occupational noise during pregnancy increased the risk of antepartum fetal death. Furthermore, higher than expected numbers of congenital anomalies in the central nervous system (CNS) were identified among women exposed to chemicals before pregnancy and to pesticides during the first trimester of pregnancy. No significant association was found between occupational exposure and intrapartum fetal death. Although recall bias may be possible in our study, the findings encourage further research.
Heat shock protein (HSP)90 functions as a general oncogene by targeting several well-known oncoproteins for ubiquination and proteasomal degradation. However, the clinical significance of HSP90, as well as the mechanisms responsible for the tumor-promoting effects of HSP90 in hepatocellular carcinoma (HCC) remain unclear. In this study, HSP90 and hypoxia-inducible factor (HIF)-1α expression in 60 samples of HCC tissues and matched normal tumor-adjacent tissue were assessed using immunohistochemistry (IHC) or western blot analysis. Flow cytometry, BrdU cell proliferation assay, caspase-3/7 activity assay and MTT assay were used to detect the apoptosis and proliferation of the HCC cells. The regulatory effect of HSP90 on HIF-1α in the HCC cells was confirmed by immunofluorescence staining, western blot analysis and RT-qPCR. The interaction between HIF-1α and HSP90 was analyzed by co-immunoprecipitation. A subcutaneous tumor xenograft model in nude mice was established and TUNEL assay was performed to evaluate cancer cell apoptosis and growth in vivo. We found that HSP90 expression was higher in the HCC tissues than in the normal tissues and that a high HSP90 expression correlated with poor clinicopathological characteristics, including venous infiltration, an advanced TNM stage and high pathological grading. Furthermore, we confirmed that patients with a negative expression of HSP90 had an improved 3-year survival, and that HSP90 was an independent factor for predicting the prognosis of patients with HCC. We demonstrated that HSP90 promoted HCC by inhibiting apoptosis and promoting cancer cell growth. Pearson's correlation coefficient analysis indicated that HSP90 expression positively correlated with HIF-1α protein expression in the HCC tissues. Furthermore, we found that HSP90 regulated HIF-1α protein abundance by inhibiting the ubiquitination and proteasomal degradation of HIF-1α in HCC cells. Additionally, the upregulation of HIF-1α expression partially abrogated HSP90 siRNA-induced HCC cell growth arrest and apoptosis in vitro and in vivo. These results indicate that HSP90 may be used as a prognostic marker and that HIF-1α may be one of the potential therapeutic targets of HSP90 in HCC.
Although in vitro studies have previously demonstrated that mitogen-activated protein kinases are important for the activation of transcription factors and the regulation of proinflammatory mediators, the function of c-Jun NH2-terminal kinase (JNK) in acute lung injury (ALI) remains to be fully elucidated. The present study aimed to investigate the effect of the JNK selective inhibitor SP600125 on lipopolysaccharide (LPS)-induced ALI. Pulmonary edema, the expression of inflammatory cytokines and pathological alterations were found to be significantly attenuated in LPS-induced ALI following treatment with SP600125 in vivo. In vitro, it was demonstrated that SP600125 administration significantly improved A549 cell viability in a dose-dependent manner using the Cell Counting kit-8 and the 5-ethynyl-2′-deoxyuridine incorporation assay. Furthermore, flow cytometric analysis demonstrated that the apoptotic rate was significantly reduced in a concentration-dependent manner following SP600125 injection. At the molecular level, SP600125 treatment dose-dependently inhibited JNK activation and upregulated claudin-4 expression in vivo and in vitro. In combination, the results from the present study indicated that the JNK inhibitor SP600125 protected against LPS-induced ALI in vivo and in vitro, possibly by upregulating the expression of claudin-4.
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