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PubMed2005

Age-related decrease in expression of peroxisome proliferator-activated receptor alpha and its effects on development of dyslipidemia.

BACKGROUND: Ageing is associated with increased incidence of dyslipidemia. To investigate potential molecular mechanisms, the effects of age and fibrate administration on peroxisome proliferator-activated receptor alpha (PPARalpha) expression in livers of young and old rats were studied. METHODS: A total of 16 young (2-month-old) and 16 old rats (24-month-old) were randomly assigned to a control group and fenofibrate group (fenofibrate in a total therapeutic dosage of 0.5% in ratio to each treated rat weight in 14 days). RT-PCR was applied to evaluate hepatic mRNA expression of PPARalpha and its target genes. Western blotting was used to determine PPARalpha protein level in liver tissue. RESULTS: When compared with 2-month-old rats, the liver tissue from 24-month-old rats showed reduced expression of PPARalpha mRNA (52%, P < 0.05) and protein (109%, P < 0.01). Consequently, the mRNA levels of PPAR target genes, LPL, ACO, ACS and CPT-1 were markedly lowered by 19%, 8%, 13% and 9% respectively, and apoCIII increased by 24% in livers from 24-month-old rats, compared with values obtained from 2-month-old rats (P < 0.05). Fenofibrate therapy significantly lowered plasma triglyceride and total cholesterol levels in old rats, accompanied with improvement in hepatic expression of genes, including LPL, ACO, ACS, CPT-1 and apoCIII, but no change was found in PPARalpha expression in livers from either 24-month or 2-month-old rats. CONCLUSIONS: The decrease in the hepatic PPARalpha expression is probably directly related to the lipid metabolic disturbances observed in old animals. The beneficial effects of fenofibrate administration in old rats suggests that fibrates may be useful for treating lipid disturbances in old people.

Aging↗

PubMed2003

[Prokaryotic expression of gene encoding Schistosoma japonicum SjE16 and its potential application in immunodiagnosis].

OBJECTIVE: To sub-clone and express the gene encoding Schistosoma japonicum calcium-binding protein (SjE16) and study its immunological response. METHODS: The specific primers were designed according to the expressed sequence tags (ESTs) sequence, which was used for amplification of the encoding sequence from the cDNA clone containing SjE16. The gene was subcloned into pGEX4T-1 plasmid and expressed. The rSjE16 was tested for its immunological response by ELISA. RESULTS: The gene encoding Schistosoma japonicum SjE16 was cloned and expressed successfully. The immunogenicity and diagnostic potential of rSjE16 were investigated. It was demonstrated by immunoassay in rabbits that the specificity and sensitivity of the test were 94.1% (16/17) and 88.2% (15/17), respectively, and the level of antibody titer of the untreated group reached a peak at 9-11 wk post infection and maintained high at least for 21 wk post infection, while the antibody level in the treated group rapidly decreased to pre-infection level in 11 wk after treatment. In human, the specificity of the test was 98.3% (57/58); the sensitivity of acute and chronic patient serum assay was 85.5% (53/62) and 70.2% (40/57), respectively. CONCLUSION: The recombinant protein of SjE16 (rSjE16) was acquired. It can be recognized by the sera from schistosomiasis patients, and the level of antibodies decreased quickly after treatment in experimental rabbits, which implicates the potential value for the evaluation of chemotherapy and detection of active infection.

Animals↗