Smoking impairs and circulating stem cells favour the protective effect of the T allele of the connexin37 gene in ischemic heart disease--A multinational study

Cardiovascular, Metabolic and Inflammatory Changes after Ovariectomy and Estradiol Substitution in Hereditary Hypertriglyceridemic Rats

Background: If menopause is really independent risk factor for cardiovascular disease is still under debate. We studied if ovariectomy in the model of insulin resistance causes cardiovascular changes, to what extent are these changes reversible by estradiol substitution and if they are accompanied by changes in other organs and tissues. Methods: Hereditary hypertriglyceridemic female rats were divided into three groups: ovariectomized at 8th week (n = 6), ovariectomized with 17-β estradiol substitution (n = 6), and the sham group (n = 5). The strain of abdominal aorta measured by ultrasound, expression of vascular genes, weight and content of myocardium and also non-cardiac parameters were analyzed. Results: After ovariectomy, the strain of abdominal aorta, expression of nitric oxide synthase in abdominal aorta, relative weight of myocardium and of the left ventricle and circulating interleukin-6 decreased; these changes were reversed by estradiol substitution. Interestingly, the content of triglycerides in myocardium did not change after ovariectomy, but significantly increased after estradiol substitution while adiposity index did not change after ovariectomy, but significantly decreased after estradiol substitution. Conclusion: Vascular and cardiac parameters under study differed in their response to ovariectomy and estradiol substitution. This indicates different effects of ovariectomy and estradiol on different cardiovascular but also extracardiac structures.

The role of connexin 37 polymorphism in spontaneous abortion

Among unique cardiovascular risk factors in women are complications during pregnancy, including miscarriage. Important risk factor is also genetic background. One of powerful candidate genes for cardiovascular disease of atherosclerotic origin (aCVD) is gene for connexin 37 (Cx37) with strong gene-environment interaction including smoking status, that is also strong risk factor for complications in pregnancy including spontaneous abortion (SA). We analyzed association between SA and Cx37 gene polymorphism (1019C>T; Pro319Ser) in 547 fetuses and its potential interaction with smoking status of mothers. Using genetic analyses from women from general population as controls, ORs for T allele, found in our previous studies to be protective against aCVD, were calculated. T allele carriers (fetuses), had OR 0.91 (95 % CI 0.72-1.14) and no interaction with smoking was observed. In conclusion, no significant association between Cx37 polymorphism and SA was observed and no modifying effect of smoking status on this association was detected.

Connexins: Key Players in the Control of Vascular Plasticity and Function

Of the 21 members of the connexin family, 4 (Cx37, Cx40, Cx43, and Cx45) are expressed in the endothelium and/or smooth muscle of intact blood vessels to a variable and dynamically regulated degree. Full-length connexins oligomerize and form channel structures connecting the cytosol of adjacent cells (gap junctions) or the cytosol with the extracellular space (hemichannels). The different connexins vary mainly with regard to length and sequence of their cytosolic COOH-terminal tails. These COOH-terminal parts, which in the case of Cx43 are also translated as independent short isoforms, are involved in various cellular signaling cascades and regulate cell functions. This review focuses on channel-dependent and -independent effects of connexins in vascular cells. Channels play an essential role in coordinating and synchronizing endothelial and smooth muscle activity and in their interplay, in the control of vasomotor actions of blood vessels including endothelial cell reactivity to agonist stimulation, nitric oxide-dependent dilation, and endothelial-derived hyperpolarizing factor-type responses. Further channel-dependent and -independent roles of connexins in blood vessel function range from basic processes of vascular remodeling and angiogenesis to vascular permeability and interactions with leukocytes with the vessel wall. Together, these connexin functions constitute an often underestimated basis for the enormous plasticity of vascular morphology and function enabling the required dynamic adaptation of the vascular system to varying tissue demands.

Interaction between CONNEXIN37 and PDE4D gene polymorphisms with susceptibility to ischemic stroke in Chinese population

The objective of this study was to test the relationship of several single nucleotide polymorphisms (SNPs) within phosphodiesterase 4D (PDE4D ) and connexin 37 (CONNEXIN37 ) gene additional interactions with ischemic stroke (IS) risk. The online software SNPstats was used for Hardy–Weinberg equilibrium testing. Generalized multifactor dimensionality reduction (GMDR) was employed to detect the potential interactions among CONNEXIN37 gene, PDE4D g ene, and smoking. The results indicated that the rs1764391-T and rs966221-G were correlated with higher IS risk, the corresponding ORs (95% CI) were 1.66 (1.21–2.03) and 1.48 (1.11–1.92), respectively. We also found that the first two loci including rs1764391 and rs918592, and the other two-loci including rs1764391 and smoking were significant in the GMDR model. Participants with rs1764391-CT/TT and rs918592-CT/TT genotype have the highest IS risk, compared to subjects with rs1764391-CC and rs918592-CC genotype, OR (95%CI) = 3.16 (1.83–4.45); smokers with rs1764391-CT/TT genotype also have the highest IS risk, compared to never smokers with rs1764391-CC genotype, OR (95%CI) = 2.82 (1.53–4.15), but no significant interaction combinations were found between gene and alcohol drinking. So in this study, the rs1764391-T and rs966221-G, rs1764391–rs918592 interaction, rs1764391–smoking interaction were all associated with higher IS susceptibility.