Abstract：
BACKGROUND: Alcohol use disorder (AUD) is a relapsing disease described as excessive use of alcohol. Evidence of the role of DNA methylation in addiction is accumulating. Ghrelin is an important peptide known as appetite hormone and its role in addictive behavior has been identified. Here we aimed to determine the methylation levels of two crucial genes (GHRL and GHSR) in ghrelin signaling and further investigate the association between methylation ratios and plasma ghrelin levels.
METHODS: Individuals diagnosed with (n = 71) and without (n = 82) AUD were recruited in this study. DNA methylation levels were measured through methylation-sensitive high-resolution melting (MS-HRM). Acylated ghrelin levels were detected by ELISA. The GHRL rs696217 polymorphism was analyzed by the standard PCR-RFLP method.
RESULTS: GHRL was significantly hypermethylated (P < 0.0022) in AUD between 25 and 50% methylation than in control subjects but no significant changes of GHSR methylation were observed. Moreover, GHRL showed significant positive correlation of methylation ratio between 25 and 50% with age. A significant positive correlation between GHSR methylation and ghrelin levels in the AUD group was determined (P = 0.037). The level of GHRL methylation and the ghrelin levels showed a significant association in the control subjects (P = 0.042).
CONCLUSIONS: GHSR and GHRL methylation levels did not change significantly between control and AUD groups. However, GHRL and GHSR methylations seemed to have associations with plasma ghrelin levels in two groups. This is the first study investigating the DNA methylation of GHRL and GHSR genes in AUD.
METHODS: Individuals diagnosed with (n = 71) and without (n = 82) AUD were recruited in this study. DNA methylation levels were measured through methylation-sensitive high-resolution melting (MS-HRM). Acylated ghrelin levels were detected by ELISA. The GHRL rs696217 polymorphism was analyzed by the standard PCR-RFLP method.
RESULTS: GHRL was significantly hypermethylated (P < 0.0022) in AUD between 25 and 50% methylation than in control subjects but no significant changes of GHSR methylation were observed. Moreover, GHRL showed significant positive correlation of methylation ratio between 25 and 50% with age. A significant positive correlation between GHSR methylation and ghrelin levels in the AUD group was determined (P = 0.037). The level of GHRL methylation and the ghrelin levels showed a significant association in the control subjects (P = 0.042).
CONCLUSIONS: GHSR and GHRL methylation levels did not change significantly between control and AUD groups. However, GHRL and GHSR methylations seemed to have associations with plasma ghrelin levels in two groups. This is the first study investigating the DNA methylation of GHRL and GHSR genes in AUD.
摘要：
背景：酒精使用障碍（AUD）是一种复发性疾病，描述为过度使用酒精。DNA甲基化在成瘾中作用的证据正在积累。Ghrelin是一种被称为食欲激素的重要肽，其在成瘾行为中的作用已被确定。在这里，我们旨在确定ghrelin信号传导中两个关键基因（GHRL和GHSR）的甲基化水平，并进一步研究甲基化比率与血浆ghrelin水平之间的关联。
方法：本研究招募诊断有（n=71）和无（n=82）AUD的个体。通过甲基化敏感性高分辨率熔解(MS-HRM)测量DNA甲基化水平。通过ELISA检测酰化生长素释放肽水平。通过标准PCR-RFLP方法分析GHRLrs696217多态性。
结果：GHRL在25％至50％甲基化的AUD中比对照组明显高甲基化（P<0.0022），但未观察到GHSR甲基化的显着变化。此外，GHRL的甲基化率在25％至50％之间与年龄呈显着正相关。AUD组GHSR甲基化与ghrelin水平呈显著正相关(P=0.037)。在对照组中，GHRL甲基化水平和ghrelin水平显示出显着相关性（P=0.042）。
结论：GHSR和GHRL甲基化水平在对照组和AUD组之间没有显著变化。然而,在两组中，GHRL和GHSR甲基化似乎与血浆ghrelin水平有关。这是第一个研究AUD中GHRL和GHSR基因的DNA甲基化。
方法：本研究招募诊断有（n=71）和无（n=82）AUD的个体。通过甲基化敏感性高分辨率熔解(MS-HRM)测量DNA甲基化水平。通过ELISA检测酰化生长素释放肽水平。通过标准PCR-RFLP方法分析GHRLrs696217多态性。
结果：GHRL在25％至50％甲基化的AUD中比对照组明显高甲基化（P<0.0022），但未观察到GHSR甲基化的显着变化。此外，GHRL的甲基化率在25％至50％之间与年龄呈显着正相关。AUD组GHSR甲基化与ghrelin水平呈显著正相关(P=0.037)。在对照组中，GHRL甲基化水平和ghrelin水平显示出显着相关性（P=0.042）。
结论：GHSR和GHRL甲基化水平在对照组和AUD组之间没有显著变化。然而,在两组中，GHRL和GHSR甲基化似乎与血浆ghrelin水平有关。这是第一个研究AUD中GHRL和GHSR基因的DNA甲基化。
