BACKGROUNDIt has been found that cardiac protection afforded by ischemic preconditioning (IPC) is significantly reduced in the senescent myocardium. ADAMTS-1 (a disintesrin and metalloprotease with thrombospondin type 1 motifs) has been shown to inhibit angiogenesis in a variety of in vitro and in vivo assays. The aim of this study was to investigate the age-associated differences in ADAMTS-1 protein expression in rat myocardium after ischemic preconditioning.

METHODSSixty-four young (4 months) and old (24 months) male Sprague-Dawley rats were randomly assigned to an IPC group (40 rats) or a sham group (rats). A model of delayed IPC was induced and rats were sacrificed and myocardial samples were harvested from the ischemic-reperfused region for immunohistochemical detection of ADAMTS-1 at serial time points after IPC. A model of myocardial infarction was produced by ligation of the left anterior descending coronary artery in additional sets of young and old rats after sham or IPC procedures, then age-associated myocardial infarction survival after IPC was calculated.

RESULTSADAMTS-1 expression increased significantly in old rats compared to young rats (P < 0.05). The mean densities of ADAMTS-1 protein at 0, 6, 12, and 24 hours in young-IPC group after IPC were 0.05 ± 0.01, 0.13 ± 0.03, 0.16 ± 0.04, and 0.12 ± 0.03 vs. 0.07 ± 0.03, 0.20 ± 0.03, 0.24 ± 0.05, and 0.21 ± 0.04 in old-IPC group. IPC resulted in diminished survival rates (5/35 vs. 6/14, old-IPC group vs. old-sham group, P < 0.05), reduced left ventricular fractional shortening ((13.9 ± 2.8)% vs. (18.3 ± 2.3)%, P < 0.05) and increased the myocardial infarction size ((37.9 ± 3.2)% vs. (32.8 ± 5.1)%, P < 0.05) in the older rats.

CONCLUSIONSCardioprotection with IPC is attenuated in the older heart. ADAMTS-1 expression induced by IPC is greater in old rats. Over-expression of anti-angiogenic factors might be a potential mechanism behind reduced protection after IPC associated with aging.

ADAM Proteins ; metabolism ; ADAMTS1 Protein ; Aging ; metabolism ; physiology ; Animals ; Immunohistochemistry ; Ischemic Preconditioning, Myocardial ; Male ; Myocardial Infarction ; metabolism ; pathology ; Myocardium ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo get the full length of human METH1 cDNA and express it steadily in mammalian cell stably.

METHODSMETH1 was amplified by RT-PCR, and cloned into pCDNA3.0 after confirmed by sequence analysis. HepG2 cells were transfected by Lipofectamine reagent and then selected in medium with G418. The expression level of METH1 was detected by RT-PCR and Western blot.

RESULTSMETH1 with expected length was effectively amplified, and completely matched the published sequence of encoding mature peptide [GI:5725505] as shown by sequence analysis. Eukaryotic vector expressing METH1 was obtained by gene cloning, cells expressing METH1 was got by selection with G418 at 3 weeks after transfection. RT-PCR and Western blot showed high level expression of METH1.

CONCLUSIONFull length of human METH1 gene is cloned successfully and expressed in HepG2 steadily, The results set up a basis for the study of effects of METH1 on hypertrophic scar angiogenesis.

ADAM Proteins ; ADAMTS1 Protein ; Angiogenesis Inhibitors ; genetics ; metabolism ; Blotting, Western ; Cell Line, Tumor ; Cloning, Molecular ; DNA, Complementary ; genetics ; metabolism ; Disintegrins ; genetics ; metabolism ; Humans ; Metalloendopeptidases ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection ; methods

OBJECTIVETo assess the association of a disintegrin and metallo-proteinase with thrombospondin type 1 motifs (ADAMTS-1) gene polymorphism and ischemic stroke caused by large artery atherosclerosis (LAA).

METHODSIn total 767 patients and 506 controls were recruited. Single nucleotide polymorphisms (SNPs) rs416905 (T/C) and rs402007 (G/C) of the ADAMTS-1 gene were genotyped by polymerase chain reaction and DNA sequencing.

RESULTSFrequencies of the rs402007 GC+CC genotype and the C allele were significantly different between the two groups (68.84% vs. 60.67%, χ2=9.012, P=0.003, OR=1.432; 45.24% vs. 38.54%, χ2=11.208, P=0.001, OR=1.318). Binary logistic regression has confirmed that the above difference was significant (P=0.001, OR=1.521, 95%CI: 1.183-1.955). The frequencies of TC+CC and GC+CC genotypes were similar between the two groups, and so was it with the C allele. The two SNPs had been in complete linkage disequilibrium (D'=1.0, r2=1.0).

CONCLUSIONThe rs416905 and rs402007 polymorphisms of the ADAMTS-1 gene may be associated with ischemic stroke caused by LAA. The C allele of the rs402007 locus may be a susceptibility factor for this subtype of stroke.

ADAM Proteins ; genetics ; ADAMTS1 Protein ; Aged ; Alleles ; Atherosclerosis ; complications ; Base Sequence ; Blood Glucose ; metabolism ; Brain Ischemia ; complications ; Fasting ; blood ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Logistic Models ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Risk Factors ; Sequence Analysis, DNA ; Smoking ; Stroke ; blood ; etiology ; genetics