Stromelysin-1 5A/6A and eNOS T-786C Polymorphisms, MTHFR C677T and A1298C Mutations, and Cigarette-Cannabis Smoking: A Pilot, Hypothesis-Generating Study of Gene-Environment Pathophysiological Associations With Buerger’s Disease

Abstract

Buerger's disease (BD) etiologies are poorly understood. Beyond smoking cessation, medical-surgical treatments have limited success. We hypothesized that mutations associated with arterial vasospasm (stromelysin-1 5A/6A, eNOS T-786C) and C677T-A1298C methylene tetrahydrofolate reductase (MTHFR) interacted with cigarette-cannabis smoking, reducing vasodilatory nitric oxide (NO), promoting arterial spasm-thrombosis. Of 21 smoking BD patients (14 men [2 siblings], 7 women; 20 white, 1 African-American), compared to 21 age-gender-race matched healthy controls, 5A/6A stromelysin- 1 homozygosity was present in 7 of 21 (33%) BD cases versus 5 of 21 (24%) controls (risk ratio 1.4; 95% confidence interval [CI] 0.5-3.7), and eNOS T-786C homozygosity was present in 3 of 21 (14%) BD cases versus 1 of 21 (5%) controls (risk ratio 3.0; 95% CI 0.3-26.6). C677T MTHFR homozygosity or compound C677T-A1298C heterozygosity was present in 7 of 21 cases (33%) versus 11 of 21 controls (52%) (risk ratio 0.6; 95% CI 0.3-1.3). In 18 patients who stopped and 3 who continued smoking, all stromelysin-1 5A/6A and/or eNOS heterozygotes-homozygotes, superficial phlebitis, lower limb gangrenous ulcers, and intractable ischemic rest pain with arterial occlusion progressed despite conventional medical therapy, threatening amputation. In 15 patients, to increase vasodilatory NO via endothelial NO synthase, l-arginine (15 g/day) was given, along with folic acid (5 mg), vitamin B6 (100 mg), and B12 (2000 mg/day) to optimize homocysteine metabolism and reduce asymmetric dimethylarginine, a NO synthase inhibitor. Unexpectedly quickly and strikingly, within 8 weeks to 8 months receiving l-arginine-folic acid, 11 of 15 treated patients improved with uniform pain reduction, ulcer healing, and in 5, full recovery of previously absent peripheral pulses. In smokers homo/heterozygous for stromelysin-1 5A/6A and eNOS T-786C mutations, we speculate that the development and severity of BD are related to a gene-environment vasospastic interaction with reduced NO-mediated vasodilatation. Increasing NO production by l-arginine while optimizing homocysteine metabolism by folic acid-B6-B12 may have therapeutic benefit. Further blinded, placebo-controlled studies are needed to determine whether our observations can be generalized to larger BD cohorts.

Sera of patients with thromboangiitis obliterans activated cultured human umbilical vein endothelial cells (HUVECs) and changed their adhesive properties

“…Of note, polymorphism in the promoter region of endothelial NO synthase gene (eNOS‐768C), and subsequent NO expression impairment, have also been detected in TAO patients . Therefore, decreasing the systemic NO levels might promote up‐regulation of endothelial cell adhesion molecules, in particular VCAM‐1 . This might explain the significant difference observed here in VCAM‐1 gene expression between TAO cases and healthy smokers and also between smokers and nonsmokers.…”

“…In addition, chronic smoking might also contribute to endothelial cell dysfunction and nitric oxide (NO) bioavailability . NO has an important role in regulating the expression of adhesion molecules on endothelial cells .…”

The eNOS T786C mutation, Prinzmetal's Variant Angina, and amelioration of angina by l-arginine in 59 patients with intractable angina despite calcium channel blocker–nitrate therapy

“…We had previously reported that L-arginine treatment improved peripheral circulation in patients with Buerger's disease with peripheral arterial vasospasm who also had the eNOS T-786C mutation [40]. Keeping this in mind we postulated that L-arginine would effectively reduce coronary artery spasm-angina in PVA which has the same eNOS T-786C mutation.…”

The Imbalance among Oxidative Biomarkers and Antioxidant Defense Systems in Thromboangiitis Obliterans (Winiwarter-Buerger Disease)

“…In agreement with literature data, our results of significantly higher levels of TOS, TAC, and their ratios in WBD patients, with respect to smoker healthy controls, suggest that smoking itself is not, per se, the only thing responsible for inducing high oxidative stress and altered antioxidant response. In fact, besides smoking habits, the increased susceptibility to develop WBD might be also due to the presence of a mutation of the T-786C eNOS gene observed in WBD patients, which, through the regulation of nitric oxide bioavailability, may impair the oxidative unbalance caused by cigarette smoke [58]. Accordingly, it has been recently hypothesized that in WBD patients, oxidative stress may originate through the NF-kB/iNOS-NO pathway, able to interact with ROS modifying cells and mitochondria membrane lipids, inducing endothelial dysfunction [51].…”