ABSTRACT
BACKGROUND:Recent studies found that some factors play important role in the process of denervated muscle atrophy, especial y the feak-headbox transcription factor, is the key element to regulate the denervated muscle atrophy. OBJECTIVE:To investigate the effect of RNA interference on inhibiting feak-headbox 3a gene expression in vitro. METHODS:The myoblast cel line L6 were cultured in the 6-wel cel culture plates, then pEGFP-N1 and smal interfering RNA recombinant plasmid with the same ratio was transfected under the Lipofectamine2000 mediation to optimize the transfection efficiency of the detection system;2μg smal interfering RNA recombinant plasmid of feak-headbox 3a gene were transfected with myoblast cel line L6 for 48 and 72 hours. RESULTS AND CONCLUSION:At 48 hours after pEGFP-N1 and siRNA recombinant plasmid transfection, a large number of bright green fluorescent displayed under fluorescence microscope with higher transfection efficiency. Real-time quantitative PCR analysis showed that there were significant differences in the sequences of feak-headbox 3a-Ⅰ, feak-headbox 3a-Ⅱ, feak-headbox 3a-Ⅲ, feak-headbox 3a-Ⅳ on feak-headbox 3a mRNA when compared with the control group at 48 and 72 hours after trasfection (Phours after transfection when compared with that at 48 hours after transfection. Western Blot gray analysis showed that there were significant differences in sequences of feak-headbox 3a-Ⅰ, feak-headbox 3a-Ⅱ, feak-headbox 3a-Ⅲ, feak-headbox 3a-Ⅳ on feak-headbox 3a mRNA when compared with the control group at 48 and 72 hours after trasfection (Psignificantly inhibit the fork-head transcription factor feak-headbox 3a gene expression, and the inhibition effect of feak-headbox 3a gene smal interfering RNA recombinant plasmid transfected with the sequence on the mRNA and protein level of feak-headbox 3a is not clear, which can provide new idea for the gene therapy of RNA mediated denervated skeletal muscle atrophy.
ABSTRACT
BACKGROUND:Previous studies have confirmed the presence of bis-(3'-5')-cyclic dimeric guanosine monophosphate signaling pathway in Streptococcus mutans, which construct the streptococcus mutans gcp gene knockout strains. OBJECTIVE:To compare the gene expression differences between Streptococcus mutans wild strains and gcp mutant strains, and to screen the biofilm-related genes from them for the fol ow-up study. METHODS:The total RNA of two kinds of strains were extracted and stained with cy3 and cy5 respectively after reverse transcription. The gene chip was scanned after hybridization and the differential gene were obtained through the data analysis. The different expression genes were verified by real-time PCR. RESULTS AND CONCLUSION:Differential genes were mainly relative about glucose metabolism and biofilm formation. We selected two genes for real-time PCR verification. The PCR results were consistent with the microarray results. After Streptococcus mutans gcp gene knockout, the gene expressions of gcp mutant strains were upregulated and the gene expressions of phosphotransferase system were downregulated, this result suggested that two different genes were related with the c-di-GMP signal pathway downstream.
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BACKGROUND:Previous studies from Shaanxi Institute of Ophthalmology have shown that ostrich cornea has the advantages to be developed into the alternatives of human corneal material. OBJECTIVE:To determine the potential toxic effects of ostrich corneal stromal scaffold on cel s. METHODS:Cel culture methods were used to culture L-929 cel s in the extracts of ostrich acel ular corneal stroma which was dried and dehydrated. 3-(4,5)-Dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide assay was used to evaluate the growth and proliferation of cel s after cultured for 1, 2 and 3 days. RESULTS AND CONCLUSION:After the cel s were cultured in the extracts of ostrich acel ular corneal stroma subjected to dryness and dehydration for 1, 3 and 5 days, and the toxicity level of cultured cel s was graded as level 1. The cytotoxicity test was conducted according to the“National Standard of the People's Republic of China GB/T16886.5-2003”. After cultured in the extracts of ostrich acel ular corneal stroma, a smal number of cel s were round in shape and loosely adherent without intracytoplasmic granules, and cel lysis could be observed occasional y. The results of 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide assay showed that the ostrich acel ular corneal stromal scaffold which was dried and dehydrated had level 1 of cytotoxicity and could be considered as a qualified material.
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BACKGROUND: α-lipoic acid is named as “nature antioxidant” and “mitochondrial nutrition”. But it is unclear whether α-lipoic acid can be used to protect skeletal muscle with chronic hypoxia exposure, as wel as the relative mechanism. OBJECTIVE: To observe the effect of α-lipoic acid on the antioxidant enzymes and oxidative stress in rat skeletal muscle with chronic hypoxia exposure, and to investigate the relative signaling pathway of α-lipoic acid. METHODS: Thirty-six Sprague Dawley rats were randomly divided into three groups: normoxia control group, hypoxia control group, and hypoxia+α-lipoic acid group. Rats in the hypoxia control group were subjected to hypoxia exposure in normobaric hypoxic tent with 11.3% oxygen concentration. Rats in the hypoxia+α-lipoic acid group were induced by adding α-lipoic acid (0.25%) in the normal diet. Al the interventions were lasted for 4 weeks. RESULTS AND CONCLUSION: α-lipoic acid in hypoxia could markedly enhance the mitochondrial Sirtuin-3 expression, improve the mitochondrial adenosine triphosphate synthesis activity and membrane potential, up-regulate the mitochondrial state 3 respiratory rate, respiratory control ratio and ratio of phosphorus to oxygen, down-regulate the mitochondrial state 4 respiratory rate and promote and up-regulate the activity of mitochondrial antioxidant enzymes such as manganese superoxide dismutase, glutathione peroxidase and catalase, thus inhibiting mitochondrial H2O2 generation rate and reducing mitochondrial malondialdehyde level. The results indicated that α-lipoic acid could improve the efficiency of energy metabolism of chronic hypoxia skeletal muscle mitochondria and inhibit reactive oxygen generation, and it could inhibit the oxidative stress through improving antioxidant enzyme activity of mitochondria. The protection mechanism of α-lipoic acid on hypoxia skeletal muscle mitochondria may be related to the increasing of mitochondrial state 3 respiratory rate.
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BACKGROUND: It is difficult to in vitro isolate and culture the ovarian surface epithelium with high purity, strong vitality and stable biological characteristics. Tissue adherence and enzymatic digestion are commonly used for primary culture, but there are certain problems in cel col ection, cel viability and cel purity. OBJECTIVE: To establish a method for primary isolating, culturing and identifying human ovarian epithelium. METHODS: The ovarian surface epithelium was obtained with cel brush innovatively, and then the cells were isolated and purified with erythrocyte spal ation and differential adherence. The epidermal growth factor was added into the serum-free Dulbecco’s modified Eagle’s medium-F12 medium for cel culture. The cel morphology was observed under inverted microscope, and hematoxylin-eosin staining and immunocytochemical staining were used to identify the cells, then the growth curve was draw. RESULTS AND CONCLUSION: The ovarian surface epithelium became adherent after cultured for 24 hours, and reached fusion basical y after cultured for 6-12 days. The cells were polygonal or flat with strong transparency and refraction. The morphological characteristics of the cells were in line with those of the normal epithelial cells, and almost al the isolated cells could express the epithelial cells surface marker CK19. The cells could be passaged for 6-8 generations with wel growth and the cel growth curve was in “S” shape. The purity of the cells was more than 95%. The results suggest that cel brush method is simple to operate and can obtain a large amount of ovarian surface epithelium rapidly. The purity of the isolated cells can reach to 95% after treated with erythrocyte spal ation and differential adherence method and the cells are in stable growth.
ABSTRACT
BACKGROUND: Telomerase can maintain the telomere length and avoid cel replicative senescence and apoptosis in somatic cells. Its catalytic subunit cal ed telomerase reverse transcriptase has roles in mediating cellsurvival and anti-apoptotic functions. OBJECTIVE: To evaluate the effects of human telomerase reverse transcriptase on amyloid β1-40-induced human embryonic cortical neurons injury. METHODS: Human cortical neurons derived from 12-16 weeks old aborted fetuses were transfected with recombinant adenovirus vector encoding human telomerase reverse transcriptase. Expression of human telomerase reverse transcriptase was evaluated by immunocytochemical staining. Telomerase activity was measured using a PCR-based telomeric repeat amplification protocol enzyme-linked immunosorbent assay kit. Human embryonic cortical neurons were treated with 10 μmol/L ol/L amyloid β1-40 after transfected for 3 days. Cel viability, reactive oxygen species levels and glutathione contents in human embryonic cortical neurons were respectively detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate and chromatometry. RESULTS AND CONCLUSION: Expression of human telomerase reverse transcriptase reached peak at 3 days after transfection, and the telomerase activity was rebuilt; 10 μmol/L amyloid β1-40 could significantly reduce the cel viability of neurons and glutathione content (P < 0.05 and P < 0.01), and increase the reactive oxygen species levels (P < 0.05). The neurons transfected with human telomerase reverse transcriptase gene could be significantly against the toxicity of amyloid β1-40 and increase the cel viability and glutathione content (P < 0.05 and P < 0.01), and decrease the reactive oxygen species levels (P < 0.05). The results indicate that human telomerase reverse transcriptase can protect amyloid β1-40-induced human embryonic cortical neurons injury