BackgroundCurrent evidence shows that the CD40–CD40 ligand (CD40–CD40L) system plays a crucial role in the development, progression and outcome of systemic lupus erythematosus (SLE). The aim of this study was to investigate whether a CD40 gene single nucleotide polymorphism (SNP) is associated with SLE and CD40 expression in the Chinese population. We included controls (n = 220) and patients with either SLE (n =205) in the study.MethodsThe gene polymorphism was measured using Snapshot SNP genotyping assays and confirmed by sequencing. We analyzed three single nucleotide polymorphisms of CD40 gene rs1883832C/T, rs1569723A/C and rs4810485G/T in 205 patients with SLE and 220 age-and sex-matched controls. Soluble CD40 (sCD40) levels were measured by ELISA.ResultsThere were significant differences in the genotype and allele frequencies of CD40 gene rs1883832C/T polymorphism between the group of patients with SLE and the control group (P < 0.05). sCD40 levels were increased in patients with SLE compared with controls (P < 0.01). Moreover, genotypes carrying the CD40 rs1883832 C/T variant allele were associated with increased CD40 levels compared to the homozygous wild-type genotype in patients with SLE. The rs1883832C/T polymorphism of CD40 and its sCD40 levels were associated with SLE in the Chinese population.ConclusionsOur results suggest that CD40 gene may play a role in the development of SLE in the Chinese population.

1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] plays an anticancer role in multiple types of cancer and potentiates the cytotoxic effects of several common chemotherapeutic agents. The hypercalcemia caused by 1,25(OH)2D3 alone or resistance to cisplatin weaken the anticancer effects of vitamin D. Thus, in this study, we aimed to investigate the synergistic effects of 1,25(OH)2D3 and cisplatin on the apoptosis and cell cycle progression of gastric cancer cells. BGC-823 human gastric cancer cells were treated with 1,25(OH)2D3 or cisplatin alone, or a combination of both agents. Cell apoptosis was assessed by TUNEL assay and flow cytometry. The expression of the apoptosis-related proteins, poly(ADP-ribose) polymerase (PARP), Bax, Bcl-2, caspase-3 and caspase-8, was examined using immunoblot analysis. ERK and AKT phosphorylation were examined by immunoblot analysis. The cell cycle distribution was determined by propidium iodide staining and flow cytometric analysis. p21 and p27 protein expression was also examined using immunoblot analysis. Our results revealed that co-treatment with 1,25(OH)2D3 enhanced cisplatin-induced apoptosis and upregulated the expression of Bax, and promoted the cleavage of PARP and caspase-3. The phosphorylation levels of ERK and AKT were reduced following combined treatment with 1,25(OH)2D3 and cisplatin. The percentage of cells in the G0/G1 phase was greater in the cells treated with the combined treatment than in those treated with either 1,25(OH)2D3 or cisplatin alone. p21 and p27 expression was upregulated following co-treatment with both agents. The results of this study suggest that 1,25(OH)2D3 potentiates cisplatin-mediated cell growth inhibition and cell apoptosis, which involves the upregulation of Bax, a decrease in ERK and AKT phosphorylation levels, and increased p21 and p27 levels.

Cardiac myocytes undergo apoptosis under conditions of high free fatty acid concentrations, including palmitate, which is implicated in lipotoxic cardiomyopathy. However, the underlying mechanisms remain unknown. The aim of the present study was to understand the role of reactive oxygen species (ROS) production and the extracellular signal‑regulated kinase 1/2 (ERK1/2) signaling pathway in palmitate‑induced apoptosis in H9c2 cells. H9c2 cells were exposed to palmitate for 12 h. The effect on the cell viability of H9c2 cells was evaluated using the 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) assay and cell apoptosis was determined by Hoechst 33342 staining. Levels of intracellular ROS were determined using a peroxide‑sensitive fluorescent probe, 2',7'‑dichlorofluorescein diacetate. Protein expression was measured by western blot analysis. Following treatment with palmitate for 12 h, H9c2 cells apoptosis was demonstrated as increased brightly condensed chromatin or unclear fragments by staining with Hoechst 33342, which was associated with increasing levels of active caspase‑3 and cleaved poly (ADP-ribose) polymerase (PARP). In this model of treatment with palmitate, H9c2 cell apoptosis correlated with increased levels of p53 and Bax expression and reduced levels of Bcl-2 expression. Palmitate‑induced apoptosis was observed to increase levels of intracellular ROS production and p‑ERK1/2 and decrease p‑Akt significantly. Consistent with these results, palmitate‑induced apoptosis was attenuated by the ERK1/2 inhibitor, U0126, through partial reduction of intracellular ROS generation. Collectively, these results indicate that palmitate‑induced apoptosis in H9c2 cells is mediated by activation of the ERK1/2 signaling pathway and increased ROS generation.

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