The Association of Mitofusion-2 Gene Polymorphisms with Susceptibility of Essential Hypertension in Northern Han Chinese Population

Mitofusin-2 gene polymorphisms and metabolic dysfunction associated fatty liver disease: a case-control study in a Chinese population

OBJECTIVES

Mitofusion-2 (Mfn2) may have a role in mitochondrial oxidative stress and insulin resistance that can promote the development of metabolic dysfunction associated fatty liver disease (MAFLD). This retrospective and case control study aimed to explore the relationships between common Mfn2 single nucleotide polymorphisms (SNPs) and MAFLD in a northern Han Chinese population.

METHODS

Six Mfn2 SNPs (rs2336384, rs873458, rs873457, rs4846085, rs2878677, and rs2236057) were genotyped using the ligase detection reaction in 466 MAFLD patients and 423 healthy controls. Genotype and allele frequencies were calculated, along with haplotype analysis and pairwise linkage disequilibrium.

RESULTS

The genotype distribution of rs2336384, rs2878677, and rs2236057 among the MAFLD patients showed a significantly different pattern from that of healthy controls. The data showed that an increased risk of MAFLD was significantly correlated with patients carrying the GG genotype of rs2336384, CC genotype of rs873457, TT genotype of rs4846085, TT genotype of rs2878677, and the AA genotype of rs2236057. Moreover, The GGCTTA haplotype was found to be adversely linked with MAFLD by haplotype analysis.

CONCLUSION

The current findings suggest a strong link between certain Mfn2 gene polymorphisms and MAFLD.

Hyperplasia suppressor gene polymorphisms and essential hypertension: a case-control association study in a central Han Chinese population

BACKGROUND

HSG (hyperplasia suppressor gene, also named Mitofusion-2, Mfn-2) gene polymorphisms have been studied as a candidate gene in essential hypertension, but no clear consensus has been reached in the Chinese population. To systematically explore their possible association, a case-control study was conducted in a central Chinese population.

METHODS AND RESULTS

We recruited 402 EH patients and 267 normotensive (NT) control subjects. A total of 6 tag SNPs of HSG gene were genotyped successfully by TaqMan assay. The results showed that genotype distribution and the allelic frequency of rs873457, rs2236384, rs4846085, and rs1474868 in the EH and NT groups were significantly different (P < 0.05), although those of rs2295281 and rs17037564 were not. rs2336384, rs873457, rs4846085 and rs1474868 were also closely associated with EH under the dominant genetic model (P < 0.05). Gender-based subgroup analyses showed that significant associations between rs873457, rs2336384, rs4846085, and rs1474868 and EH could be found in males, but not in females. Haplotype analysis indicated that the C-G-T-T-T-G haplotype was positively correlated with EH.

CONCLUSION

Our study suggested that HSG gene polymorphisms were significantly associated with EH in a central Han Chinese population, especially in male subjects.

Single Nucleotide Polymorphisms (SNPs) Genotyping Reveals that Mfn2 Polymorphisms are Associated with Thoracic Aortic Dissection in Han Chinese Population

BACKGROUND Many studies have shown that hypertension may contribute to thoracic aortic dissection (TAD). Among the factors that modulate hypertension are endoplasmic reticulum stress and vascular smooth muscle cell proliferation which are in turn modulated by mitofusion-2 (Mfn2). Specifically, we determined, in the Han Chinese population, whether single nucleotide polymorphisms (SNPs) of Mfn2 influenced the occurrence of TAD. MATERIAL AND METHODS Six tagging SNPs of Mfn2 (rs2236057, rs3766741, rs2236058, rs17037564, rs2295281, and rs2336384) were genotyped using a TaqMan assay in 200 TAD patients and 451 health individuals from the Han Chinese population. RESULTS Logistic regression analysis indicated CC genotype of rs2295281 was highly linked to an increased risk of TAD (TT+CT versus CC, OR=0.540, 95% CI [0.320-0.911], P=0.021), implying that TT genotype and CT genotype of rs2295281 have a lower risk for TAD. Logistic regression analysis also indicated that rs2236058 was highly linked to the risk of TAD based on recessive genetic model, which indicated that the GG genotype was a protective factor against TAD (GG versus (CG+CC), OR=0.545, 95% CI [0.351-0.845], P=0.007). CG genotype and CC genotype of rs2236058 had a higher risk for TAD. In addition, rs2236058 was linked to the risk of TAD in the recessive genetic and homozygous models in the normotensive subgroup (GG versus (CG+CC), OR=0.298, 95% CI [0.112-0.792], P=0.015; GG versus CC, OR=0.528, 95% CI [0.302-0.925], P=0.026) but not in the hypertension subgroup. CONCLUSIONS Our findings showed that the occurrence of TAD in a Han Chinese population was influenced by Mfn2 polymorphisms.

A Prediction Model of Essential Hypertension Based on Genetic and Environmental Risk Factors in Northern Han Chinese

Background: Essential hypertension (EH) is a chronic disease of universal high prevalence and a well-established independent risk factor for cardiovascular and cerebrovascular events. The regulation of blood pressure is crucial for improving life quality and prognoses in patients with EH. Therefore, it is of important clinical significance to develop prediction models to recognize individuals with high risk for EH. Methods: In total, 965 subjects were recruited. Clinical parameters and genetic information, namely EH related SNPs were collected for each individual. Traditional statistic methods such as t-test, chi-square test and multi-variable logistic regression were applied to analyze baseline information. A machine learning method, mainly support vector machine (SVM), was adopted for the development of the present prediction models for EH. Results: Two models were constructed for prediction of systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively. The model for SBP consists of 6 environmental factors (age, BMI, waist circumference, exercise [times per week], parental history of hypertension [either or both]) and 1 SNP (rs7305099); model for DBP consists of 6 environmental factors (weight, drinking, exercise [times per week], TG, parental history of hypertension [either and both]) and 3 SNPs (rs5193, rs7305099, rs3889728). AUC are 0.673 and 0.817 for SBP and DBP model, respectively. Conclusions: The present study identified environmental and genetic risk factors for EH in northern Han Chinese population and constructed prediction models for SBP and DBP.

Involvement of mitochondrial fission in calcium sensing receptor-mediated vascular smooth muscle cells proliferation during hypertension

Hyperproliferation of vascular smooth muscle cells (VSMC) is a major risk factor for cardiovascular diseases. Proper mitochondrial fission and fusion is involved with VSMC function. However, the role and mechanism of mitochondrial morphological changes in VSMC proliferation are not well understood. Here, we found that calcium sensing receptor (CaSR) was increased in the aortas from spontaneous hypertensive rats (SHRs) compared with age-matched Wistar Kyoto (WKY) rats. There was also an increase in mitochondrial fission and VSMC proliferation, which was attenuated by Calhex231. In primary rat VMSC, angiotensin II (Ang II) stimulation induced cytosolic [Ca²⁺]_i increase, mitochondrial shortening and proliferation, all of which could be attenuated by pretreatment with mitochondrial division inhibitor-1 (Mdivi-1) and Calhex231. Our data indicate that CaSR-mediated mitochondrial fission could be a therapeutic target for hyperproliferative disorders.