Cytotoxic T Lymphocyte-associated Antigen 4 Polymorphisms Correlated with Graves' Disease in Patients of Han Ethnicity in Yunnan, China / Polimorfismos del antígeno 4 del linfocito T citotóxico correlacionados con la enfermedad de Graves en pacientes de la etnia Han en Yunnan, China

ABSTRACT Objective: To investigate the correlations between polymorphisms at position 49 in exon 1 and position 318 in the promoter of the cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) gene and autoimmune thyroid diseases in a Han Chinese population. Methods: Polymerase chain reaction-restriction fragment length polymorphism was utilized. The MseI and BbvI restriction endonucleases were used to detect and analyse position 49 in exon 1 and position 318 in the promoter as well as the T/C alleles of the CTLA-4 gene in peripheral blood samples from 112 patients with Graves' disease (GD), 101 with Hashimoto's thyroiditis (HT) and 100 healthy individuals. Results: At position 49 of exon 1, the frequencies of the GG genotype and the G allele in the GD group (χ2 = 12.147; p = 0.002) were statistically significantly higher than those in the control group (χ2 = 9.925; p = 0.002), while no statistically significant differences were found between the frequencies of the GG genotype and the G allele in the HT group (χ2 = 1.195; p = 0.550) and those in the control group (χ2 = 0.984; p = 0.321). No statistically significant differences in the promoter (−318) or the T/C alleles were observed among the three groups. Position 49 in the 17th codon of exon 1 of the CTLA-4 gene may be a candidate susceptibility marker in patients of Han ethnicity with GD. Conclusion: This finding helps us to better understand the genetic risks for GD and provides a direction for targeted gene therapy.

RESUMEN Objetivo: Investigar las correlaciones entre los polimorfismos en la posición 49 en el exón 1 y la posición 318 en el promotor del gen del antígeno 4 asociado al linfocito T citotóxico (CTLA-4), con las enfermedades autoinmunes de la tiroides en una población China de Han. Métodos: Se utilizó la reacción en cadena de la polimerasa-polimorfismo de la longitud de los fragmentos de restricción. Las endonucleasas de restricción de MseI y BbvI se utilizaron para detectar y analizar la posición 49 en el exón 1 y la posición 318 en el promotor, así como los alelos T/C del gen CTLA-4 en muestras de sangre periférica de 112 pacientes con enfermedad de Graves (EG), 101 con tiroiditis de Hashimoto (TH) y 100 individuos sanos. Resultados: En la posición 49 de exón 1, las frecuencias del genotipo GG y el alelo G en el grupo de EG (χ2 = 12.147; p = 0.002) fueron estadísticamente significativamente más altas que las del grupo de control (χ2 = 9.925; p = 0.002), pero no se encontraron diferencias estadísticamente significativas entre las frecuencias del genotipo GG y el alelo G en el grupo de TH (χ2 = 1.195; p = 0.550) y las del grupo de control (χ2 = 0.984; p = 0.321). No se observaron diferencias estadísticamente significativas en el promotor (−318) ni en los alelos T/C entre los tres grupos. La posición 49 en el codón17.° del exón 1 del gen CTLA-4 puede ser un marcador de susceptibilidad candidato en pacientes de la etnia Han con EG. Conclusión: Este hallazgo nos ayuda a comprender mejor los riesgos genéticos de la EG y ofrece una dirección para la terapia génica dirigida.

Effect of penehyclidine hydrochloride on -arrestin-1 expression in lipopolysaccharide-induced human pulmonary microvascular endothelial cells

β-arrestins are expressed proteins that were first described, and are well-known, as negative regulators of G protein-coupled receptor signaling. Penehyclidine hydrochloride (PHC) is a new anti-cholinergic drug that can inhibit biomembrane lipid peroxidation, and decrease cytokines and oxyradicals. However, to date, no reports on the effects of PHC on β-arrestin-1 in cells have been published. The aim of this study was to investigate the effect of PHC on β-arrestin-1 expression in lipopolysaccharide (LPS)-induced human pulmonary microvascular endothelial cells (HPMEC). Cultured HPMEC were pretreated with PHC, followed by LPS treatment. Muscarinic receptor mRNAs were assayed by real-time quantitative PCR. Cell viability was assayed by the methyl thiazolyl tetrazolium (MTT) conversion test. The dose and time effects of PHC on β-arrestin-1 expression in LPS-induced HPMEC were determined by Western blot analysis. Cell malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were measured. It was found that the M3 receptor was the one most highly expressed, and was activated 5 min after LPS challenge. Furthermore, 2 μg/mL PHC significantly upregulated expression of β-arrestin-1 within 10 to 15 min. Compared with the control group, MDA levels in cells were remarkably increased and SOD activities were significantly decreased in LPS pretreated cells, while PHC markedly decreased MDA levels and increased SOD activities. We conclude that PHC attenuated ROS injury by upregulating β-arrestin-1 expression, thereby implicating a mechanism by which PHC may exert its protective effects against LPS-induced pulmonary microvascular endothelial cell injury.