Objective To investigate the mitochondrial energy metabolism in D-galactoseinduced cell ageing model.Methods MRC-5 cells were cultivated for 72 hours in a medium containing 55 mmol/L D-galactose.The analysis of cell proliferation capacity by CCK8 method,β-galactosidase staining and detection of p21 protein expression level were performed for identifying cell senescence.The cell oxidation-reduction state was evaluated by an analysis of cellular ROS levels,SOD activity,MDA content and oxidative damage level of mitochondrial DNA(mtDNA).For purpose of detecting mitochondrial function and its impairment,mitochondrial morphology was observed by electron microscope,mitochondrial quantity was analyzed by flow cytometry,mitochondrial membrane potential(△Ψm) was measured by JC-1 staining,and ATP content was analyzed by HPLC,and mitochondrial oxygen consumption rate was detected by Seahorse cell energy metabolism detection system.Results The decreased MRC-5 cell proliferation,up-expression of p21 protein,increased β-galactosidase activity were observed in D-Gal-treated cells,which indicated the cell premature senescence.When treated with D-Gal,the significantly increased ROS and MDA level,decreased SOD activity and increased oxidized mtDNA proved that the cells kept higher oxidative stress.D-Gal induced-mitochondrial impairment was evidenced by the dimming of mitochondrial cristae and double membrane structure,decrease of transmembrane potential and ATP synthesis,and decrease of its oxygen consumption rate(OCR).Conclusions The 55 mmol/L D-Gal causes an impairment of mitochondrial structure and a decrease of function of energy metabolism,which is associated with cellular senescence induced by D-Gal.

Objective To detect mutations in the PTPN11 gene in a family with LEOPARD syndrome (LS).Methods Clinical data were collected from a 7-year-old boy patient with LS.Peripheral blood was obtained from the patient,both of his parents,and 50 healthy controls.All the exons and their flanking sequences of the PTPN11 gene were amplified by PCR followed by direct DNA sequencing.Results A heterozygous missense mutation c.836A ＞ G,which resulted in a substitution of TAT by TGT at codon 279,was found in exon 7 of the PTPN11 gene in the patient.No mutation was detected in the unaffected parents or healthy controls.Conclusion The missense mutation c.836A ＞ G may be the cause of the phenotype of LS in this family.

This study was designed to investigate the effect of salidroside on Sjogren's syndrome in mice and its mechanism.Mice in negative control group and model group were given normal saline intragastric administration,mice in 3 salidroside groups were given salidroside intragastric administration(doses of 20,40 and 80 mg/kg),and mice in positive control group were given hydroxychloroquine sulfate(100 mg/kg)intragastric administration once a day.After continuous intragastric administration for 8 weeks,water intake and saliva flow rate were detected,infiltrated submandibular gland lymphocytes were evaluated,the levels of IL-17,IL-10,NF-κB P65 and IκBα and the ratio of Th17/Treg cells were detected.In the model group,the acinus atrophied with unclear margin and decreasing in number,and the lymphocyte infiltration were observed and lymphocyte focus was formed.After the intervention with salidroside and hydroxychloroquine sulfate,the degree of acinus lesions was relieved to a certain extent,and the lymphocyte infiltration was reduced.Compared with negative control group,water intake,salivary flow rate,submandibular gland index,IL-10 and IκBα levels were decreased in other groups,while lymphocyte infiltration,the levels of IL-17,IL-17/IL-10,NF-κB P65 and NF-κB P65/IκBα were increased(P<0.05).Compared with model group,water intake,salivary flow rate,submandibular gland index,IL-10 and IκBα levels were increased in each salidroside dose group,while submandibular gland lymphocyte infiltration,the levels of IL-17,IL-17/IL-10,NF-κB P65 and NF-κB P65/IκBα decreased in a dose-dependent manner(P<0.05).Compared with the negative control group,the proportion of Th17 cells in the serum of model group was increased,and the proportion of Treg cells was decreased,while salidroside in all doses could reverse these changes(P<0.05).Taken together,salidroside alleviates submandibular gland inflammatory responses by mediating Th17/Treg immune balance and inhibiting NF-κB P65/IκBα,thus playing a therapeutic role in SS treatment.