BACKGROUND:The biological behavior of mesenchymal stem cells is influenced by the survival microenvironment.Pre-treatment of the microenvironment is an important means of regulating the function of mesenchymal stem cells. OBJECTIVE:To compare the differences in paracrine function of umbilical cord mesenchymal stem cells and adipose mesenchymal stem cells under oxidative stress and hypoxia,and to provide a theoretical basis for selecting appropriate pretreatment of mesenchymal stem cells to treat different diseases. METHODS:Umbilical cord mesenchymal stem cells and adipose mesenchymal stem cells were cultured by H2O2 or O2 oxygen,respectively,and cell morphology,proliferation,viability and paracrine factor expression were examined. RESULTS AND CONCLUSION:(1)The expression levels of brain-derived neurotrophic factor and transforming growth factor-β were higher in umbilical cord mesenchymal stem cells than in adipose mesenchymal stem cells under a normal culture environment,while the expressions of stromal cell-derived factor-1α and tumor necrosis factor stimulating factor-6 in the adipose mesenchymal stem cells were significantly higher than those in the umbilical cord mesenchymal stem cells.(2)There was no significant difference in the effect of low and moderate levels(≤100 μmol/L)of H2O2 on the viability of the two mesenchymal stem cells.However,increasing the H2O2 concentration from 50 μmol/L to 100 μmol/L resulted in a distinct increase in vascular endothelial growth factor expression in umbilical cord mesenchymal stem cells.The expression of basic fibroblast growth factor,vascular endothelial growth factor,stromal cell-derived factor-1α and interleukin-10 in adipose mesenchymal stem cells was greatly increased by increasing H2O2 concentration in this range.(3)1%O2 hypoxia promoted mesenchymal stem cell proliferation.After 24 hours of culture in 1%O2,gene expression levels were elevated in both mesenchymal stem cells,but the expression levels of vascular endothelial growth factor,interleukin-10 and tumor necrosis factor stimulating factor-6 were significantly higher in adipose mesenchymal stem cells than in umbilical cord mesenchymal stem cells.(4)It is concluded that hypoxia and oxidative stress preconditioning enhances the paracrine function of mesenchymal stem cells.However,mesenchymal stem cells respond differently to hypoxia and oxidative stress.Treating diseases can choose suitable mesenchymal stem cells for appropriate pretreatment to further enhance their therapeutic potential.

Macroautophagy (referred to as autophagy hereafter) is a major intracellular lysosomal degradation pathway that is responsible for the degradation of misfolded/damaged proteins and organelles. Previous studies showed that autophagy protects against acetaminophen (APAP)-induced injury (AILI) via selective removal of damaged mitochondria and APAP protein adducts. The lysosome is a critical organelle sitting at the end stage of autophagy for autophagic degradation via fusion with autophagosomes. In the present study, we showed that transcription factor EB (TFEB), a master transcription factor for lysosomal biogenesis, was impaired by APAP resulting in decreased lysosomal biogenesis in mouse livers. Genetic loss-of and gain-of function of hepatic TFEB exacerbated or protected against AILI, respectively. Mechanistically, overexpression of TFEB increased clearance of APAP protein adducts and mitochondria biogenesis as well as SQSTM1/p62-dependent non-canonical nuclear factor erythroid 2-related factor 2 (NRF2) activation to protect against AILI. We also performed an unbiased cell-based imaging high-throughput chemical screening on TFEB and identified a group of TFEB agonists. Among these agonists, salinomycin, an anticoccidial and antibacterial agent, activated TFEB and protected against AILI in mice. In conclusion, genetic and pharmacological activating TFEB may be a promising approach for protecting against AILI.

Small interfering RNA (siRNA) has a promising future in the treatment of ocular diseases due to its high efficiency, specificity, and low toxicity in inhibiting the expression of target genes and proteins. However, due to the unique anatomical structure of the eye and various barriers, delivering nucleic acids to the retina remains a significant challenge. In this study, we rationally design PACD, an A-B-C type non-viral vector copolymer composed of a hydrophilic PEG block (A), a siRNA binding block (B) and a pH-responsive block (C). PACDs can self-assemble into nanosized polymeric micelles that compact siRNAs into polyplexes through simple mixing. By evaluating its pH-responsive activity, gene silencing efficiency in retinal cells, intraocular distribution, and anti-angiogenesis therapy in a mouse model of hypoxia-induced angiogenesis, we demonstrate the efficiency and safety of PACD in delivering siRNA in the retina. We are surprised to discover that, the PACD/siRNA polyplexes exhibit remarkable intracellular endosomal escape efficiency, excellent gene silencing, and inhibit retinal angiogenesis. Our study provides design guidance for developing efficient nonviral ocular nucleic acid delivery systems.

Objective:To analyze the correlation between clinical phenotypes and genotypes in 6 children with primary distal renal tubular acidosis (dRTA).Methods:The clinical data of 6 children confirmed as dRTA in Wuhan Children′s Hospital, Tongji Medical College, Huazhong University of Science & Technology from November 2017 to August 2019 were collected, and related auxiliary examination was performed to assess their growth and development.The venous whole blood was reserved for Trio whole exome sequencing, and full spectrum genetic disease accurate diagnosis cloud platform was applied to systematic data screening and analysis.The suspected mutations were checked by Sanger sequencing, and then the role of protein was predicted by software.Results:Clinical manifestations, signs and auxiliary examination results of the 6 children accorded with the diagnostic criteria of dRTA, and the prominent characteristics was growth retardation.One case had knee valgus, one had osteoporosis, and the auxiliary examination results showed that both of them had alkaline urine, metabolic acidosis, and hypokalemia.Three children had nephrocalcinosis, and 2 children had nephrolithiasis.The parents of the 6 patients were all normal without phenotypes.Mutations in the SLC4A1 gene were identified in 4 patients, including 1 child with a reported homozygous autosomal recessive missense mutation(c.2102G>A, p.G701D), who had dRTA and hemolytic anemia, and 3 children with the reported de novo heterozygous autosomal dominant missense mutation(c.1766G>A, p.R589H, c.1765C>T, p.R589C), whose age at diagnosis was related to abnormal renal imaging.Compound heterozygous autosomal recessive mutations in the ATPV1B1 gene were identified in 1 patient, and they were novel heterozygous missense mutations (1153C>A, p.P385T and c. 806C>T, p.P269L). A novel homozygous autosomal recessive missense mutation was identified in 1 patient in the ATPV0A4 gene(c.1899C>A, p.Y633X, 208). Conclusions:Mutations in SLC4A1, ATP6V1B1, ATP6V0A4 genes are identified as the main causes of the primary dRTA, and the phenotypes was related to the mutation features and genotypes.Genetic test should be conducted on patients suspected as dRTA for early molecular diagnosis, thereby improving clinical phenotypic screening and individualized treatment.

The endoplasmic reticulum(ER)is an intracellular organelle consisting of a continuous network of membranes.In the liver,the ER is highly active in protein modification,lipid metabolism,and xenobiotic detoxification.Maintaining these complicated processes requires elaborate control of the ER lumen environment as well as the ER volume.Increasing evidence suggests that autophagy plays a critical role in regulating the homeostasis of hepatic ER contents and levels of cytochrome P450(CYP)enzymes via selective ER-phagy.This review will provide an overview of ER-phagy,summarizing the possible roles of recently identified ER-phagy receptor proteins in regulating the homeostasis of hepatic ER and CYP enzymes as well as outlining the various implications of ER-phagy in ER-related liver diseases.

Objective To analyze neuraminidase(NA) inhibitor resistance of seasonal H1N1 influenza A viruses isolated in Shenzhen during 2008 to 2009. Methods The NA gene of these viruses were sequenced. Phylogenetic analysis of the sequences was performed with Mega3. 1 software. Results In 2008, most isolates of the seasonal H1 N1 virus were susceptible to neuraminidase inhibitors, but the H275Y mutation in the neuraminidase gene region associated with high-level oseltamivir resistance had been detected in 92.6% of the strains isolated in 2009. Furthermore, a strain with Q136K was found, which showed the resistance to Zanamivir. Conclusion In the light of emerging resistance, close monitoring and understanding of the nature and dynamics of resistance mutations in influenza virus should be a priority.

Objective To study the prevalence and variation of influenza B viruses of Shenzhen. Methods Fifty strains influenza B viruses in Shenzhen from 1994 to 2006 were selected. HA1 gene were amplified by RT-PCR and sequenced. Phylogenetic analysis of HA1 was conducted by MEGA program. Results The influenza B viruses of Shenzhen were divided into Yamagata and Victoria lineage. The two lineages prevailed respectively in different years from 1994 to 2006. The variance of glycosylation site and some mutations of antigenic determinants were detected in the two lineages. Conclusion The viruses of Yamagata and Victoria lineage prevailed respectively in different years in Shenzhen but the mutation rates of the two lineages were slowly.

Objective To analyze the genetic characteristics of H1N1 influenza viruses isolated in Shenzhen during 1995 to 2007. Methods The hemagglutinin(HA) gene of these viruses were sequenced. Phylogenetic analysis of the sequences was performed with Simmonic and Mega software. Results The H1N1 influenza viruses isolated in Shenzhen from 1995 to 2007 were divided into chide A, B and C. Some viruses from 2005 to 2006 clustered in the same group with the viruses of 2001. Furthermore, some of the vaccine strains recommended by WHO were found lagged behind the strains isolated in Shenzhen. Some mu-tations occurred on the antigenic sites as well as receptor-binding site(RBS). Except the viruses of 1995, the other viruses had deleted at the site 137. Conclusion Characterization of the HA gene revealed that most of the amino acid substitutions occurred on the antigenic sites and RBS. Furthermore, it was discovered that the mutations occurred on different antigenic regions in different years.

Objective: To study the relation between hyperglycemia and mechanical ventilatory time, the days in the intensive care unit,infection rate,mortality . Methods: 572 patients' blood glucose levels in the morning were measured,and divided into two groups by the level of 7.78 mmol/L.The mechanical ventilatory time, days in the intensive care unit,infection rate and mortality were compared between two groups. Results: The mechanical time,stay in ICU and infection rate in the group with blood glucose level below 7.78 mmol/L were significantly less than in the group with blood glucose level above 7.78 mmol/L(P

0.05). Serum IL-10 and IL-10/TNF? ratio in the dead were significantly higher than that in the survivors( P 0.05). Conclusions The septic patients with high serum IL-10 or IL-10/TNF? ratio fared with poor prognosis.