BACKGROUND:Long non-coding RNA(LncRNA)plays an important role in nervous system development and neurological diseases.Previous studies by the research team have demonstrated that human umbilical cord mesenchymal stem cells overexpressing erythropoietin(EPO-MSCs)under ischemic and hypoxic conditions have better neuroprotective functions and significantly activate the expression of LncRNA XIST.Research suggests that XIST is related to the pathogenesis of hypoxic-ischemic encephalopathy,but the role and mechanism of its regulation by EPO-MSCs in protecting ischemic-hypoxic neurons remain unclear.OBJECTIVE:To explore the new mechanism by which LncRNA XIST,in response to EPO-MSC signaling,affects the apoptosis of ischemic-hypoxic SH-SY5Y cells.METHODS:(1)SH-SY5Y cell lines with knockdown of LncRNA XIST(sh-XIST)and negative control(NC-XIST)were constructed through lentiviral transfection.Oxygen-glucose deprivation was used to induce ischemic-hypoxic injury in the cells.Transwell chambers were used to create a non-contact co-culture system with EPO-MSCs,sh-XIST,and NC-XIST ischemic-hypoxic SH-SY5Y cells.Cell proliferation ability was detected using the CCK-8 assay.Cell migration ability was assessed using the scratch assay,and cell apoptosis was measured by flow cytometry.(2)RNA-seq bioinformatics analysis was performed to screen for differentially expressed genes and pathways between sh-XIST and NC-XIST cell lines.Dual-luciferase experiments were used to verify the relationship between miR-124-3p and the target genes XIST and GRIN1.qRT-PCR was conducted to validate the expression levels of downstream miR-124-3p and GRIN1 genes.(3)miR-124-3p inhibitors and mimics were added to verify phenotypic changes in SH-SY5Y cells after ischemic-hypoxic injury and co-culture with EPO-MSCs.RESULTS AND CONCLUSION:(1)Compared with the NC-XIST group,SH-SY5Y cells in the sh-XIST group showed reduced proliferation and migration abilities and increased apoptosis after ischemic-hypoxic injury and co-culture with EPO-MSCs.(2)Dual-luciferase experiments showed that miR-124-3p interacted with the target gene XIST.SH-SY5Y cells transfected with miR-124-3p mimics and co-cultured with EPO-MSCs showed decreased apoptosis after ischemic-hypoxic injury,while SH-SY5Y cells transfected with miR-124-3p inhibitors showed increased apoptosis after co-culture with EPO-MSCs.(3)Transcriptomic sequencing and bioinformatics analysis of sh-XIST revealed significant downregulation of the neuroactive ligand-receptor pathway and the key receptor gene GRIN1 for central nervous system development.(4)Dual-luciferase experiments showed that miR-124-3p interacted with GRIN1.GRIN1 expression was significantly downregulated in the sh-XIST group after ischemic-hypoxic injury compared with the NC-XIST group.These findings indicate that LncRNA XIST promotes GRIN1 expression by upregulating miR-124-3p,thereby reducing cell apoptosis after ischemic-hypoxic injury and co-culture with EPO-MSCs and enhancing proliferation and migration.sh-XIST can block this protective function.

BACKGROUND:Long non-coding RNA(LncRNA)plays an important role in nervous system development and neurological diseases.Previous studies by the research team have demonstrated that human umbilical cord mesenchymal stem cells overexpressing erythropoietin(EPO-MSCs)under ischemic and hypoxic conditions have better neuroprotective functions and significantly activate the expression of LncRNA XIST.Research suggests that XIST is related to the pathogenesis of hypoxic-ischemic encephalopathy,but the role and mechanism of its regulation by EPO-MSCs in protecting ischemic-hypoxic neurons remain unclear.OBJECTIVE:To explore the new mechanism by which LncRNA XIST,in response to EPO-MSC signaling,affects the apoptosis of ischemic-hypoxic SH-SY5Y cells.METHODS:(1)SH-SY5Y cell lines with knockdown of LncRNA XIST(sh-XIST)and negative control(NC-XIST)were constructed through lentiviral transfection.Oxygen-glucose deprivation was used to induce ischemic-hypoxic injury in the cells.Transwell chambers were used to create a non-contact co-culture system with EPO-MSCs,sh-XIST,and NC-XIST ischemic-hypoxic SH-SY5Y cells.Cell proliferation ability was detected using the CCK-8 assay.Cell migration ability was assessed using the scratch assay,and cell apoptosis was measured by flow cytometry.(2)RNA-seq bioinformatics analysis was performed to screen for differentially expressed genes and pathways between sh-XIST and NC-XIST cell lines.Dual-luciferase experiments were used to verify the relationship between miR-124-3p and the target genes XIST and GRIN1.qRT-PCR was conducted to validate the expression levels of downstream miR-124-3p and GRIN1 genes.(3)miR-124-3p inhibitors and mimics were added to verify phenotypic changes in SH-SY5Y cells after ischemic-hypoxic injury and co-culture with EPO-MSCs.RESULTS AND CONCLUSION:(1)Compared with the NC-XIST group,SH-SY5Y cells in the sh-XIST group showed reduced proliferation and migration abilities and increased apoptosis after ischemic-hypoxic injury and co-culture with EPO-MSCs.(2)Dual-luciferase experiments showed that miR-124-3p interacted with the target gene XIST.SH-SY5Y cells transfected with miR-124-3p mimics and co-cultured with EPO-MSCs showed decreased apoptosis after ischemic-hypoxic injury,while SH-SY5Y cells transfected with miR-124-3p inhibitors showed increased apoptosis after co-culture with EPO-MSCs.(3)Transcriptomic sequencing and bioinformatics analysis of sh-XIST revealed significant downregulation of the neuroactive ligand-receptor pathway and the key receptor gene GRIN1 for central nervous system development.(4)Dual-luciferase experiments showed that miR-124-3p interacted with GRIN1.GRIN1 expression was significantly downregulated in the sh-XIST group after ischemic-hypoxic injury compared with the NC-XIST group.These findings indicate that LncRNA XIST promotes GRIN1 expression by upregulating miR-124-3p,thereby reducing cell apoptosis after ischemic-hypoxic injury and co-culture with EPO-MSCs and enhancing proliferation and migration.sh-XIST can block this protective function.

Objective: To explore the growth characteristics of rat calvaria by detecting the calvaria of SD rats in different periods. Methods: The calvaria of SD rats at 1 , 4 , 7 , 10 , and 12 weeks from the same littermate were selected (3 rats per week) . Real⁃time PCR and Western blot techniques were used to detect the expression of focal adhesion kinase ( FAK) Ⅳ phosphatidylinositol 3 kinase/protein kinase B ( PI3K/AKT ) signal pathway in the calvaria , and the role of FAK⁃PI3K/AKT in the growth and development of the calvaria was analyzed by correlation. Results: The increase of brain volume and the thickness of calvaria increased synchronously , the expression of FAK was positively correlated with the changes of meridians , and the expression of FAK was positively correlated with the expression of PI3K/AKT. Conclusion The expression of FAK is related to the growth and development of rat skull. FAK plays a role in calvaria by activating PI3K/AKT signal pathway. FAK may be used as a marker of rapid skull growth and development , which provides a basic theoretical basis for the timing of clinical skull defect repair and treatment.

Objective:Through reading a lot of literature on the critical path planning of FDA, analyzed the contribution and shortage of the critical path plan to China's medical device market access system.Methods: To analyze the critical path planning of FDA by using the method of literature review.Results: China should reference the critical path plan, reform the existing medical instrument market access system, improve the efficiency, simplify the procedure and promote the safety and development of the product.Conclusion: The research on the critical path planning of FDA is very important for the construction of China's modern medical device market access path.

This paper introduced the significance parameters of the quality control of cold light source of endoscope, expounded the importance and necessity of quality control of cold light source; it investigated several manufacturers, analyzed and discussed the main causes of the cold light source uneven, in order to realized the standard management and effective supervision on the cold light source, at the end, the next step quality control work was brought out, which provide technical support for quality supervision of cold light source.
Endoscopes ; standards ; Light ; Quality Control

This paper introduced the significance parameters of the quality control of cold light source of endoscope, expounded the importance and necessity of quality control of cold light source; it investigated several manufacturers, analyzed and discussed the main causes of the cold light source uneven, in order to realized the standard management and effective supervision on the cold light source, at the end, the next step quality control work was brought out, which provide technical support for quality supervision of cold light source.

Aim To clone apoptosis-related genes from human MCF-7 breast cancer cells and to analyze the character of the method used in the process. Methods A poptotic cell model of MCF-7 cells was established with the apoptotic tumor cells induced by the all-trans-retinoic acid. The apoptotic gene was cloned from the model by improved PCR-based subtractive hybridization. Results 5 clones were identified to be related to apoptosis by reverse dot blot, 4 of them were known genes, and 3 were related to apoptosis. A novel gene， named apmcf-1, coded for 47 amino acid was identified. This gene was accepted by Genbank, the accession number was AF141882. Conclusion This improved PCR-based subtractive hybridization may be an efficient way in cloning differential expression gene.