OBJECTIVETo study the effects of androgen on the expression of phosphacan and NG2 proteoglycan (NG2) and neurite regeneration in neonatal rats with hypoxic-ischemic brain damage (HIBD) and the potential mechanism underlying the protective effect of androgen against HIBD.

METHODSOne hundred and twenty neonatal Sprague-Dawley rats were randomly divided into three groups: sham-operated, HIBD and androgen treatment. HIBD was induced by the ligation of left common carotid artery and hypoxia exposure. The androgen treatment group rats were injected with testosterone propionate (25 mg/kg) immediately after HIBD. Phosphacan and NG2 expression in the cortex and the hippocampus was detected with the immunohistochemical method 24 and 72 hrs and 7 and 10 days after hypoxia-ischemia (HI). The ultrastructure and neurite regeneration of neurons in the cortex and the hippocampus were observed under a transmission electron microscope.

RESULTSThe neurite regeneration was obvious in the sham-operated group, but seldom in the HIBD group. The androgen treatment group showed increased neurite regeneration compared with the HIBD group. There were fewer phosphacan and NG2 positive cells in the cortex and the hippocampus in the sham-operated group. Phosphacan and NG2 expression in the cortex and the hippocampus was observed at 24 hrs, increased at 72 hrs, and peaked at 7 days after HI in the HIBD group and remained at a higher expression 10 days after HI than in the sham-operated group. The levels of phosphacan and NG2 expression in the cortex and the hippocampus in the androgen treatment group were significantly reduced compared with those in the HIBD group 24 and 72 hrs and 7 and 10 days after HI (P<0.01).

CONCLUSIONSPhosphacan and NG2 may be important inhibitory factors for neurite regeneration following HIBD in neonatal rats. The neuroprotection of androgen against neonatal HIBD is produced possibly through an inhibition of phosphacan and NG2 expression.

Animals ; Animals, Newborn ; Antigens ; analysis ; Brain Chemistry ; drug effects ; Female ; Hypoxia-Ischemia, Brain ; physiopathology ; Immunohistochemistry ; Male ; Microscopy, Electron, Transmission ; Nerve Regeneration ; drug effects ; Neurites ; physiology ; ultrastructure ; Proteoglycans ; analysis ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptor-Like Protein Tyrosine Phosphatases, Class 5 ; analysis ; Testosterone Propionate ; pharmacology

OBJECTIVETo investigate the difference in methylation of PTPRG gene between gastric primary cancer and its lymph node metastases, and its regulation by 5-Aza-2'-deoxycytidin in a gastric cancer cell line SGC7901.

METHODSMethylation-specific polymerase chain reaction (MSP) and RT-PCR were applied to identify the difference between gastric primary cancer and lymph node metastases and assess the changes of methylation in gastric cancer cell line SGC7901 treated by 5-Aza-2'-deoxycytidin.

RESULTSThere were significant differences of PTPRG gene methylation and PTPRG mRNA expression between gastric primary cancer and lymph node metastases: a linear regression analysis revealed a significant association between the quantity of metastatic lymph nodes and their methylation rate. A statistied relationship between methylation of PTPRG gene and loss of PTPRG mRNA expression was detected. PTPRG gene methylation in the gastric cancer cell line changed into negative and PTPRG mRNA expression in the cell line was recovered after 5-Aza-2'-deoxycytidin treatment.

CONCLUSIONThere is a difference of PTPRG gene methylation in gastric primary cancer and metastatic lymph nodes. 5-Aza-2'-deoxycytidin, an inhibitor of DNA methylation, can recovery the expression of PTPRG gene.

Azacitidine ; analogs & derivatives ; pharmacology ; Cell Line, Tumor ; DNA Methylation ; DNA Modification Methylases ; antagonists & inhibitors ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Lymph Nodes ; metabolism ; pathology ; Lymphatic Metastasis ; RNA, Messenger ; metabolism ; Receptor-Like Protein Tyrosine Phosphatases, Class 5 ; genetics ; Stomach Neoplasms ; genetics ; metabolism ; pathology

BACKGROUNDFetal insulin hypothesis was proposed that the association between low birth weight and type 2 diabetes is principally genetically mediated. The aim of this study was to investigate whether common variants in genes CDKAL1, HHEX, ADCY5, SRR, PTPRD that predisposed to type 2 diabetes were also associated with reduced birthweight in Chinese Han population.

METHODSTwelve single nucleotide polymorphisms (rs7756992/rs10946398 in CDKAL1, rs1111875 in HHEX, rs391300 in SRR, rs17584499 in PTPRD, rs1170806/rs9883204/rs4678017/rs9881942/rs7641344/rs6777397/rs6226243 in ADCY5) were genotyped in 1174 unrelated individuals born in Peking Union Medical College Hospital from 1921 to 1954 by TaqMan allelic discrimination assays, of which 645 had normal glucose tolerance, 181 had developed type 2 diabetes and 348 impaired glucose regulation. Associations of these 12 genetic variants with birthweight and glucose metabolism in later life were analyzed.

RESULTSBirthweight was inversely associated with CDKAL1-rs10946398 (β = -41 g [95% confidence interval [CI]: -80, -3], P = 0.034), common variants both associated with increased risk of impaired glucose metabolism and decreased insulin secretion index later in life. After adjusting for sex, gestational weeks, parity and maternal age, the risk allele of CDKAL1-rs7756992 was associated with reduced birthweight (β = -36 g [95% CI: -72, -0.2], P = 0.048). The risk allele in SRR showed a trend toward a reduction of birthweight (P = 0.085).

CONCLUSIONSThis study identified the association between type 2 diabetes risk variants in CDKAL1 and birthweight in Chinese Han individuals, and the carrier of risk allele within SRR had the trend of reduced birthweight. This demonstrates that there is a clear overlap between the genetics of type 2 diabetes and fetal growth, which proposes that lower birth weight and type 2 diabetes may be two phenotypes of one genotype.

Adenylyl Cyclases ; genetics ; Aged ; Alleles ; Asian Continental Ancestry Group ; genetics ; Birth Weight ; genetics ; Cyclin-Dependent Kinase 5 ; genetics ; Diabetes Mellitus, Type 2 ; genetics ; Female ; Genetic Predisposition to Disease ; genetics ; Homeodomain Proteins ; genetics ; Humans ; Infant, Low Birth Weight ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; genetics ; Receptor-Like Protein Tyrosine Phosphatases, Class 2 ; genetics ; Transcription Factors ; genetics ; tRNA Methyltransferases