[Study on the relationship of the haplotypes of programmed cell death 1 gene and ultraviolet history with systemic lupus erythematosus].

OBJECTIVE: To investigate the relationship of gene polymorphisms of programmed cell death 1 gene (PDCD1) and ultraviolet history with systemic lupus erythematosus (SLE) among the Han population in the southern region of yangtze river in China. METHODS: With a case control design, a total of 159 SLE cases and 159 controls were enrolled in this study, and single nucleotide polymorphisms (SNPs) of the PDCD1 gene were determined by PCR-restriction fragment length polymorphism (RFLP). With the aid of the logistic regression model, the effect of gene polymorphism, environmental factor and the interaction between gene and environment were fitted under the recessive, dominant, additive and codominant mode, respectively. RESULTS: Three models were screened as the optimal models under the additive mode and one model under the dominant mode, according to the lowest value of Akaike's Information Criteria (AIC). After the control of age and gender, it was found that the frequency of ultraviolet exposure was higher in cases than in controls with significant difference under all models (P<0.05). For the haplotypes composed of the alleles of PD1.2, PD1.5 and PD1.6, there was significantly higher frequency of G-T-A haplotype (0.1196 vs 0.0363) and lower frequency of A-C-A haplotype (0.4746 vs 0.5399) in cases than that in controls (P<0.05) under the additive mode, and the G-T-A haplotype was associated with an increased risk for SLE (OR=4.319), while A-C-A haplotype was shown as a protective factor for SLE (OR=0.571). Moreover, interaction between A-C-G haplotype and ultraviolet exposure, which was related to an increased risk for SLE (beta5=1.182, Z=2.2898, P<0.05, OR=3.261), was also found under this mode. Additionally, the frequency of G-C-G haplotype was higher in cases than that in controls (0.1287 vs 0.0361) under the dominant mode with statistically significant difference (P<0.05, OR=4.332). CONCLUSION: Authors' results indicate that ultraviolet exposure, G-T-A or G-C-G haplotype and interaction between A-C-G and ultraviolet exposure may be associated with genetic susceptibility to SLE in Han population in the southern region of yangtze river in China under certain genetic modes.

[Interactions between susceptible genes and risk environmental factors in Chinese females with systemic lupus erythematosus].

OBJECTIVE: To explore the interactions of gene polymorphisms of cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death 1 (PDCD-1) with risk environmental factors in individuals with systemic lupus erythematosus (SLE) from Han nationality female population in South of Changjiang River region of China. METHODS: With a case-only design, a total of 258 cases were enrolled in this study, and single nucleotide polymorphisms (SNPs) of the PDCD-1 and CTLA-4 genes were determined by means of PCR-RFLP. With the aid of Poisson loglinear mode, interactions between gene-gene and gene-environment were fitted under the dominant, recessive, additive and multiple models, respectively. RESULTS: It was found that interaction existed between GG genotype of PD1.6 and UV history under separate inherent models of the recessive mode (OR = 3.714, 95%CI: 1.235 - 11.179) and additive mode (OR = 3.199, 95%CI: 1.023 - 10.004). For CTLA-4 locus, there existed interactions between TT/TC genotype of -1722T-->C and UV history under the dominant model (OR = 4.874, 95%CI: 1.119 - 21.242), and interaction between T allele and UV history was also found under the multiple model (OR = 1.470, 95%CI: 1.047 - 2.065). While, under the additive mode for CTLA-4, it was found that interactions existed between TT genotype of -1722T-->C and UV history (OR = 4.744, 95%CI: 1.037 - 21.737), as well as between TC genotype of -1722T-->C and UV history (OR = 4.973, 95%CI: 1.110 - 22.287). CONCLUSION: The interactions between UV history and polymorphisms of CTLA-4 and PDCD-1 gene for SLE were observed, which indicates that there may be association of their interactions with the development of SLE in Han nationality females population in the south regions of Changjiang River in China.

Inhibitory effects of Baicalin on ultraviolet B-induced photo-damage in keratinocyte cell line.

Baicalin, one kind of Chinese herbal medicine with anti-inflammatory and anti-oxidant property, has been commonly used as a clinical medicine. However, little has been known about the effects of Baicalin on ultraviolet (UV) induced photo-aging and photo-carcinogenesis. The photoproduct is critical to the initial event of UV-induced photo-carcinogenesis. The purpose of the present study was to investigate whether Baicalin, in immortalized human keratinocyte HaCaT cells, could inhibit ultraviolet-B (UVB) induced skin damage and its possible underlying mechanisms, such as inhibiting UVB-induced cytotoxicity and apoptosis, cyclobutane pyrimidine dimers (CPDs), down-regulating the expression of regulatory proteins which are related to cell apoptosis and DNA damage/repair. Our study revealed that Baicalin treatment could inhibit the UVB-induced cytotoxicity, apoptosis and CPD level. It also decreased the mRNA expression of apoptosis-regulatory genes (p53-p21 and c-fos), the protein levels of p53, proliferating cell nuclear antigen (PCNA) and repair protein A (RPA), and the secretion of cytokines [interleukin(IL)-6 and tumor necrosis factor (TNF-alpha)]. These results suggested that Baicalin may have an inhibitory effect on the UVB-induced photo-damage by blocking the relevant cytokine secretion and expression of p53-p21, c-fos, PCNA and RPA genes.