The association of the blood lead level and serum lipid concentrations may be modified by the genetic combination of the metallothionein 2A polymorphisms rs10636 GC and rs28366003 AA.

BACKGROUND: Lead in blood can stimulate lipid oxidation in phosphatidylcholine and increase peroxidation in lipids. Metallothionein (MT) is a cysteine-rich protein that can influence the detoxification of heavy metals and scavenge oxidative stress for free radicals. One of the most expressive functional genes in humans is the MT2A gene. OBJECTIVE: This study aims to determine if the association of the blood lead level and lipid biomarkers was influenced by MT2A polymorphisms. METHODS: We recruited 677 participants after informed consent was obtained. All the samples collected were analyzed for lipid biomarkers and blood lead levels and were genotyped for MT2A polymorphisms by reverse transcription polymerase chain reaction. A short questionnaire collected the medical history and alcohol and cigarette consumption information. The data were used for descriptive analyses and linear regression models. RESULTS: The investigation revealed that lead elevated concentration increased low-density lipoprotein cholesterol and decreased high-density lipoprotein cholesterol (HDL-C) by multiple linear models. The carriers of the rs10636 GC-rs28366003 AA genetic combination may be less susceptive to lead elevated concentration on HDL-C than other types. CONCLUSION: In conclusion, the association of the blood lead level and HDL-C may be modified by the MT2A genetic combination: the rs10636 GC-rs28366003 AA genotype could play a protective role in lead elevated concentration on HDL-C in humans.

Associations of the PTPN22 and CTLA-4 genetic polymorphisms with Taiwanese ankylosing spondylitis.

Ankylosing spondylitis (AS) is an autoimmune disease, and the imbalance of peripheral tolerance is involved in its pathogenesis. Importantly, the negative signal of activated T cells plays a crucial role in the balance of peripheral tolerance. It has been postulated that human protein tyrosine phosphatase nonreceptor 22 (PTPN22) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) genes encode proteins that are actively involved in regulating T-cell activation. Therefore, we evaluated the effects of PTPN22 and CTLA-4 genotypes on the occurrence of AS. Genetic polymorphisms of PTPN22 -1123G/C and CTLA-4 +49A/G were identified by polymerase chain reaction for 391 AS patients and 391 healthy controls. Subjects with PTPN22 CC and GC genotypes had a greater risk of AS occurrence than those with PTPN22 GG genotype [relative risk = 1.39, 95 % confidence interval (95 % CI) 1.03-1.88]. Further, subjects with PTPN22 CC/CTLA-4 AA or PTPN22 GC/CTLA-4 AA genotypes had 1.90-fold (95 % CI 1.02-3.49) greater risk of AS development than those with other combinations of PTPN22 and CTLA-4 genotypes. Our findings indicated that PTPN22 -1123G/C and CTLA-4 +49A/G genetic polymorphisms have a combined effect on the development of AS.