Objective

The objectives of the present research were to ascertain the relationship of Leucine-Rich Repeat-Containing G-Protein Coupled Receptors 6 (LGR6) methylation and transcript levels with ankylosing spondylitis (AS).

Methods

Targeted bisulfite sequencing was applied to analyze LGR6 DNA methylation in 81 AS cases and 81 controls. Besides, the LGR6 transcription level of peripheral blood mononuclear cells (PBMCs) from 70 AS cases and 64 controls was measured utilizing quantitative real-time transcription-polymerase chain reaction (qRT-PCR).

Results

The study detected the methylation levels of 43 sites in two CpG (cytosine-guanine dinucleotide) islands of LGR6 and found that LGR6 were significantly hypomethylated in AS patients (LGR6_1: P = 0.002; LGR6_2: P < 0.001). LGR6 transcript level was obviously reduced in AS (P = 0.001) and was positively related to DNA methylation level (CpG-1: P = 0.010; CpG-2: P = 0.007). Besides, the Receiver operating characteristic curve (ROC) exhibited good diagnostic performance of LGR6 methylation level (AUC = 0.676, 95% CI = 0.594–0.758, P < 0.001). Further subgroup analysis revealed that gender may affect the LGR6_1 methylation pattern.

Conclusion

The present study revealed that LGR6 DNA methylation dysregulation may be involved in the pathogenesis of AS from an epigenetic perspective for the first time, with the aim of providing new directions for biomarker identification and treatment development for AS patients.

中文翻译：

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强直性脊柱炎中DNA甲基化和LGR6基因的表达：病例对照研究

客观的

本研究的目的是确定富含亮氨酸重复序列的 G 蛋白偶联受体 6 ( LGR6 ) 甲基化和转录水平与强直性脊柱炎 (AS) 的关系。

方法

应用靶向亚硫酸氢盐测序分析81 例 AS 病例和 81 例对照的LGR6 DNA 甲基化。此外，利用定量实时转录聚合酶链式反应 (qRT-PCR) 测量了 70 名 AS 病例和 64 名对照者的外周血单核细胞 (PBMC) 的LGR6转录水平。

结果

研究检测了LGR6两个CpG（胞嘧啶-鸟嘌呤二核苷酸）岛43个位点的甲基化水平，发现AS患者中LGR6显着低甲基化（LGR6_1：P=  0.002；LGR6_2：P  <0.001）。AS中LGR6转录水平明显降低（P =  0.001），并且与DNA甲基化水平呈正相关（CpG-1：P  = 0.010；CpG-2：P  = 0.007）。此外，受试者工作特征曲线（ROC）对LGR6甲基化水平表现出良好的诊断性能（AUC = 0.676，95% CI = 0.594–0.758，P  < 0.001）。进一步的亚组分析显示，性别可能影响LGR6_1甲基化模式。

结论

本研究首次从表观遗传学角度揭示LGR6 DNA甲基化失调可能参与AS的发病机制，旨在为AS患者的生物标志物鉴定和治疗开发提供新的方向。