Maghajothi Sakthisree, Subramanian Lakshmi, Mani Preethi, Singh Mrityunjay, Iyer Dhanya R, Sharma Saurabh, Khullar Madhu, Victor Suma M, Asthana Shailendra, Mullasari Ajit S, Mahapatra Nitish R
Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai.
Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana.
J Hypertens. 2022 Nov 1;40(11):2147-2160. doi: 10.1097/HJH.0000000000003234. Epub 2022 Jul 22.
Matrix metalloproteinase 8 (MMP8) has a prominent role in collagen turnover in blood vessels and vascular remodeling. The contribution of regulatory single nucleotide polymorphisms in MMP8 to cardiovascular diseases is unclear. We aimed to delineate the influence of MMP8 promoter variations on hypertension.
A case-control study in unrelated individuals ( n = 2565) was carried out. Resequencing of the MMP8 proximal promoter, linkage disequilibrium analysis, genotyping of variants and regression analyses were performed. MMP8 promoter-reporter constructs were generated and expressed in human vascular endothelial cells under various conditions.
We identified four single nucleotide polymorphisms (SNPs) in the promoter region of MMP8 : -1089A/G (rs17099452), -815G/T (rs17099451), -795C/T (rs11225395), -763A/T (rs35308160); these SNPs form three major haplotypes. Hap3 (viz., GTTT haplotype) carriers showed significant associations with hypertension in two geographically distinct human populations (e.g., Chennai: odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.16-1.86, P = 2 × 10 -3 ; Chandigarh: OR = 1.85, 95% CI = 1.21-2.81, P = 4 × 10 -3 ). Hap3 carriers also displayed elevated systolic blood pressure, diastolic blood pressure and mean arterial pressure levels. Hap3 promoter-reporter construct showed lower promoter activity than the wild-type (Hap1) construct. In silico analysis and molecular dynamics studies predicted diminished binding of the transcription factor nuclear factor kappa B (NF-κB) to the functional -815T allele of Hap3 compared to the -815G wild-type allele; this prediction was validated by in-vitro experiments. Hap3 displayed impaired response to tumor necrosis factor-alpha treatment, possibly due to weaker binding of NF-κB. Notably, MMP8 promoter haplotypes were identified as independent predictors of plasma MMP8 and endothelial dysfunction markers (von Willebrand factor and endothelin-1) levels.
MMP8 promoter GTTT haplotype has a functional role in reducing MMP8 expression during inflammation via diminished interaction with NF-κB and in enhancing the risk of hypertension.
基质金属蛋白酶8（MMP8）在血管中的胶原蛋白周转和血管重塑中起重要作用。MMP8中调控单核苷酸多态性对心血管疾病的影响尚不清楚。我们旨在阐明MMP8启动子变异对高血压的影响。
对无关个体（n = 2565）进行病例对照研究。进行了MMP8近端启动子的重测序、连锁不平衡分析、变异基因分型和回归分析。构建了MMP8启动子-报告基因构建体，并在各种条件下在人血管内皮细胞中表达。
我们在MMP8启动子区域鉴定出四个单核苷酸多态性（SNP）：-1089A/G（rs17099452）、-815G/T（rs17099451）、-795C/T（rs11225395）、-763A/T（rs35308160）；这些SNP形成三种主要单倍型。单倍型3（即GTTT单倍型）携带者在两个地理位置不同的人群中与高血压有显著关联（例如，金奈：比值比[OR]=1.47，95%置信区间[CI]=1.16-1.86，P = 2×10-3；昌迪加尔：OR = 1.85，95% CI = 1.21-2.81，P = 4×10-3）。单倍型3携带者还表现出收缩压、舒张压和平均动脉压水平升高。单倍型3启动子-报告基因构建体的启动子活性低于野生型（单倍型1）构建体。计算机分析和分子动力学研究预测，与-815G野生型等位基因相比，转录因子核因子κB（NF-κB）与单倍型3的功能性-815T等位基因的结合减少；这一预测通过体外实验得到验证。单倍型3对肿瘤坏死因子-α治疗的反应受损，可能是由于NF-κB的结合较弱。值得注意的是，MMP8启动子单倍型被确定为血浆MMP8和内皮功能障碍标志物（血管性血友病因子和内皮素-1）水平的独立预测因子。
MMP8启动子GTTT单倍型在炎症过程中通过减少与NF-κB的相互作用降低MMP8表达以及增加高血压风险方面具有功能性作用。
