Association of COL4A3 (rs55703767), MMP-9 (rs17576)and TIMP-1 (rs6609533) gene polymorphisms with susceptibility to type 2 diabetes

Comparison of genetic and epigenetic profiles of periodontitis according to the presence of type 2 diabetes

Type 2 diabetes mellitus (T2DM) and periodontitis (PD) have intricated connections as chronic inflammatory diseases. While the immune response is a key factor that accounts for their association, the underlying mechanisms remain unclear. To gain a deeper understanding of the connection, we conducted research using a multiomics approach. We generated whole genome and methylation profiling array data from the periodontium of PD patients with DM (PDDM) and without DM to confirm genetic and epigenetic changes. Independent bulk and single-cell RNA sequencing data were employed to verify the expression levels of hypo-methylated genes. We observed a gradual rise in C>T base substitutions and hypomethylation in PD and PDDM patients compared with healthy participants. Furthermore, specific genetic and epigenetic alterations were prominently associated with the Fc-gamma receptor-mediated phagocytosis pathway. The upregulation of these genes was confirmed in both the periodontal tissues of PD patients and the pancreatic tissues of T2DM patients. Through single-cell RNA analysis of peripheral blood mononuclear cells, substantial upregulation of Fc-gamma receptors and related genes was particularly identified in monocytes. Our findings suggest that targeting the Fc-gamma signaling pathway in monocytes holds promise as a potential treatment strategy for managing systemic complications associated with diabetes.

Investigation of missense mutation-related type 1 diabetes mellitus through integrating genomic databases and bioinformatic approach

Though genes are already known to be responsible for type 1 diabetes mellitus (T1DM), the knowledge of missense mutation of that disease gene has still to be under covered. A genomic database and a bioinformatics-based approach are integrated in the present study in order to address this issue. Initially, nine variants associated with T1DM were retrieved from the GWAS catalogue. Different genomic algorithms such as PolyPhen2.0, SNPs and GTEx analyser programs were used to study the structural and functional effects of these mutations. Subsequently, SNPnexus was also employed to understand the effect of these mutations on the function of the expressed protein. Nine missense variants of T1DM were identified using the GWAS catalogue database. Among these nine SNPs, three were predicted to be related to the progression of T1DM disease by affecting the protein level. TYK2 gene variants with SNP rs34536443 were thought to have a probably damaging effect. Meanwhile, both COL4A3 and IFIH1 genes with SNPs rs55703767 and rs35667974, respectively, might alter protein function through a possibly damaging prediction. Among the variants of the three genes, the TYK2 gene with SNP rs34536443 had the strongest contribution in affecting the development of T1DM, with a score of 0.999. We sincerely hope that the results could be of immense importance in understanding the genetic basis of T1DM.

Diacylglycerol kinase delta overexpression improves glucose clearance and protects against the development of obesity

BACKGROUND AND AIM

Diacylglycerol kinase (DGK) isoforms catalyze an enzymatic reaction that removes diacylglycerol (DAG) and thereby terminates protein kinase C signaling by converting DAG to phosphatidic acid. DGKδ (type II isozyme) downregulation causes insulin resistance, metabolic inflexibility, and obesity. Here we determined whether DGKδ overexpression prevents these metabolic impairments.

METHODS

We generated a transgenic mouse model overexpressing human DGKδ2 under the myosin light chain promoter (DGKδ TG). We performed deep metabolic phenotyping of DGKδ TG mice and wild-type littermates fed chow or high-fat diet (HFD). Mice were also provided free access to running wheels to examine the effects of DGKδ overexpression on exercise-induced metabolic outcomes.

RESULTS

DGKδ TG mice were leaner than wild-type littermates, with improved glucose tolerance and increased skeletal muscle glycogen content. DGKδ TG mice were protected against HFD-induced glucose intolerance and obesity. DGKδ TG mice had reduced epididymal fat and enhanced lipolysis. Strikingly, DGKδ overexpression recapitulated the beneficial effects of exercise on metabolic outcomes. DGKδ overexpression and exercise had a synergistic effect on body weight reduction. Microarray analysis of skeletal muscle revealed common gene ontology signatures of exercise and DGKδ overexpression that were related to lipid storage, extracellular matrix, and glycerophospholipids biosynthesis pathways.

CONCLUSION

Overexpression of DGKδ induces adaptive changes in both skeletal muscle and adipose tissue, resulting in protection against HFD-induced obesity. DGKδ overexpression recapitulates exercise-induced adaptations on energy homeostasis and skeletal muscle gene expression profiles.

Matrix Metalloproteinases in Cardioembolic Stroke: From Background to Complications

Matrix metalloproteinases (MMPs) are endopeptidases participating in physiological processes of the brain, maintaining the blood-brain barrier integrity and playing a critical role in cerebral ischemia. In the acute phase of stroke activity, the expression of MMPs increase and is associated with adverse effects, but in the post-stroke phase, MMPs contribute to the process of healing by remodeling tissue lesions. The imbalance between MMPs and their inhibitors results in excessive fibrosis associated with the enhanced risk of atrial fibrillation (AF), which is the main cause of cardioembolic strokes. MMPs activity disturbances were observed in the development of hypertension, diabetes, heart failure and vascular disease enclosed in CHA₂DS₂VASc score, the scale commonly used to evaluate the risk of thromboembolic complications risk in AF patients. MMPs involved in hemorrhagic complications of stroke and activated by reperfusion therapy may also worsen the stroke outcome. In the present review, we briefly summarize the role of MMPs in the ischemic stroke with particular consideration of the cardioembolic stroke and its complications. Moreover, we discuss the genetic background, regulation pathways, clinical risk factors and impact of MMPs on the clinical outcome.

Identification of Comorbidities, Genomic Associations, and Molecular Mechanisms for COVID-19 Using Bioinformatics Approaches

Several studies have been done to identify comorbidities of COVID-19. In this work, we developed an analytical bioinformatics framework to reveal COVID-19 comorbidities, their genomic associations, and molecular mechanisms accomplishing transcriptomic analyses of the RNA-seq datasets provided by the Gene Expression Omnibus (GEO) database, where normal and infected tissues were evaluated. Using the framework, we identified 27 COVID-19 correlated diseases out of 7,092 collected diseases. Analyzing clinical and epidemiological research, we noticed that our identified 27 diseases are associated with COVID-19, where hypertension, diabetes, obesity, and lung cancer are observed several times in COVID-19 patients. Therefore, we selected the above four diseases and performed assorted analyses to demonstrate the association between COVID-19 and hypertension, diabetes, obesity, and lung cancer as comorbidities. We investigated genomic associations with the cross-comparative analysis and Jaccard's similarity index, identifying shared differentially expressed genes (DEGs) and linking DEGs of COVID-19 and the comorbidities, in which we identified hypertension as the most associated illness. We also revealed molecular mechanisms by identifying statistically significant ten pathways and ten ontologies. Moreover, to understand cellular physiology, we did protein-protein interaction (PPI) analyses among the comorbidities and COVID-19. We also used the degree centrality method and identified ten biomarker hub proteins (IL1B, CXCL8, FN1, MMP9, CXCL10, IL1A, IRF7, VWF, CXCL9, and ISG15) that associate COVID-19 with the comorbidities. Finally, we validated our findings by searching the published literature. Thus, our analytical approach elicited interconnections between COVID-19 and the aforementioned comorbidities in terms of remarkable DEGs, pathways, ontologies, PPI, and biomarker hub proteins.

Matrixmetalloproteinase-9 gene polymorphism (rs 17576) increases the risk of depressive symptoms in bipolar disorder

Objectives

Plasticity of neural synapses is known to be involved in the complications in bipolar disorder (BD) patients. Matrix metalloproteinases (MMPs) play a role in synaptic plasticity and memory. Even though elevated MMP-9 levels are reported in neuropsychiatric disorders, there is limited data about MMP-9 gene polymorphism in BD. The objectives of the study was to investigate genotype frequency and allele frequency of MMP-9 genetic variant (rs 17576) in BD and its association with disease severity.

Materials and Methods

Eighty BD cases and 80 controls were recruited in the study. MMP-9 genotyping and allele frequency and plasma MMP-9 levels were analyzed in both the groups. Hamilton depression rating scale and Young's Mania Rating Scale (YMRS) were used to evaluate severity of BD.

Results

The genotype and minor allele (G allele) frequency were not significant between BD and controls. MMP-9 levels were significantly increased in BD patients with AG (P < 0.001) and GG (P = 0.022) genotypes compared to controls. BD patients with GG genotype (P = 0.038, OR: 3.26 (1.16-9.09), and G (mutant) allele (P = 0.013, OR 2.03(1.18-3.48) confer increased risk of depressive symptoms. MMP-9 was positively correlated with YMRS scale (r = 0.227, P = 0.043) in BD.

Conclusion

MMP-9 gene polymorphism (rs 17576) is linked with depressive symptoms in BD.

Matrix Metalloproteinases and Glaucoma

Matrix metalloproteinases (MMPs) are enzymes that decompose extracellular matrix (ECM) proteins. MMPs are thought to play important roles in cellular processes, such as cell proliferation, differentiation, angiogenesis, migration, apoptosis, and host defense. MMPs are distributed in almost all intraocular tissues and are involved in physiological and pathological mechanisms of the eye. MMPs are also associated with glaucoma, a progressive neurodegenerative disease of the eyes. MMP activity affects intraocular pressure control and apoptosis of retinal ganglion cells, which are the pathological mechanisms of glaucoma. It also affects the risk of glaucoma development based on genetic pleomorphism. In addition, MMPs may affect the treatment outcomes of glaucoma, including the success rate of surgical treatment and side effects on the ocular surface due to glaucoma medications. This review discusses the various relationships between MMP and glaucoma.

Association of MMP-2 and MMP-9 Polymorphisms with Diabetes and Pathogenesis of Diabetic Complications

Type 2 diabetes mellitus (T2D) affects millions of people around the world, and its complications have serious health consequences. In addition to external factors, the causes of morbidity and increased risk were also sought in the variability of the human genome. A phenomenon that can answer these questions is the occurrence of single-nucleotide polymorphisms (SNP). They constitute a field for research into genetic determinants responsible for the increase in the risk of the discussed metabolic disease. This article presents the outline of two enzymes: metalloproteinases 2 and 9 (MMP-2, MMP-9), their biological activity and the effect caused by differences in individual alleles in the population, as well as the reports on the importance of these DNA sequence variations in the occurrence of diabetes mellitus type 2 and associated conditions. The results of the conducted research indicate a relationship between two MMP-2 polymorphisms (rs243865, rs243866) and two MMP-9 polymorphisms (rs3918242, rs17576) and the presence of T2D. This could offer a promising possibility to use them as predictive and diagnostic markers. However, due to the low number of reports, more research is needed to clearly confirm the link between these SNPs and diabetes.

Single-nucleotide polymorphisms as important risk factors of diabetes among Middle East population

Diabetes is a chronic metabolic disorder that leads to the dysfunction of various tissues and organs, including eyes, kidneys, and cardiovascular system. According to the World Health Organization, diabetes prevalence is 8.8% globally among whom about 90% of cases are type 2 diabetes. There are not any significant clinical manifestations in the primary stages of diabetes. Therefore, screening can be an efficient way to reduce the diabetic complications. Over the recent decades, the prevalence of diabetes has increased alarmingly among the Middle East population, which has imposed exorbitant costs on the health care system in this region. Given that the genetic changes are among the important risk factors associated with predisposing people to diabetes, we examined the role of single-nucleotide polymorphisms (SNPs) in the pathogenesis of diabetes among Middle East population. In the present review, we assessed the molecular pathology of diabetes in the Middle East population that paves the way for introducing an efficient SNP-based diagnostic panel for diabetes screening among the Middle East population. Since, the Middle East has a population of 370 million people; the current review can be a reliable model for the introduction of SNP-based diagnostic panels in other populations and countries around the world.

Potential underlying genetic associations between keratoconus and diabetes mellitus

Background Keratoconus (KC) is the most common ectatic corneal disease, characterized by significantly localized thinning of the corneal stroma. Genetic, environmental, hormonal, and metabolic factors contribute to the pathogenesis of KC. Additionally, multiple comorbidities, such as diabetes mellitus, may affect the risk of KC. Main Body Patients with diabetes mellitus (DM) have been reported to have lower risk of developing KC by way of increased endogenous collagen crosslinking in response to chronic hyperglycemia. However, this remains a debated topic as other studies have suggested either a positive association or no association between DM and KC. To gain further insight into the underlying genetic components of these two diseases, we reviewed candidate genes associated with KC and central corneal thickness in the literature. We then explored how these genes may be regulated similarly or differentially under hyperglycemic conditions and the role they play in the systemic complications associated with DM. Conclusion Our comprehensive review of potential genetic factors underlying KC and DM provides a direction for future studies to further determine the genetic etiology of KC and how it is influenced by systemic diseases such as diabetes.

Association of the functionally significant polymorphisms of the MMP9 gene with H. pylori-positive gastric ulcer in the Caucasian population of Central Russia

Background and purpose

The study analyzed the association of functionally significant polymorphisms of matrix metalloproteinases (MMPs) genes with the development of gastric ulcer (GU) in Caucasians from Central Russia.

Methods

The 781 participants, including 434 patients with GU (196 Helicobacter pylori (H. pylori)-positive and 238 H. pylori-negative) and 347 controls (all H. pylori-negative) were recruited for the study. Ten SNPs of the MMP1 (rs1799750), MMP2 (rs243865), MMP3 (rs679620), MMP8 (rs1940475), and MMP9 (rs3918242, rs3918249, rs3787268, rs17576, rs17577, and rs2250889) genes were considered for association with GU using multiple logistic regression. The SNPs associated with GU and loci linked (r²≥0.8) to them were analyzed in silico for their functional assignments.

Results

The SNPs of the MMP9 gene were associated with H. pylori-positive GU: alleles C of rs3918249 (OR = 2.02, p_perm = 0.008) and A of rs3787268 (OR = 1.60–1.82, p_perm ≤ 0.016), and eight haplotypes of all studied MMP9 gene SNPs (OR = 1.85–2.04, p_perm ≤ 0.016) increased risk for H. pylori-positive GU. None of the analyzed SNPs was independently associated with GU and H. pylori-negative GU. Two haplotypes of the MMP9 gene (contributed by rs3918242, rs3918249, rs17576, and rs3787268) increased risk for GU (OR = 1.62–1.65, p_perm ≤ 0.006). Six loci of the MMP9 gene, which are associated with H. pylori-positive GU, and 65 SNPs linked to them manifest significant epigenetic effects, have pronounced eQTL (17 genes) and sQTL (6 genes) values.

Conclusion

SNPs of the MMP9 were associated with H. pylori-positive GU but not with H. pylori-negative GU in Caucasians of Central Russia.

Association of Collagen Gene (COL4A3) rs55703767 Variant With Response to Riboflavin/Ultraviolet A-Induced Collagen Cross-Linking in Female Patients With Keratoconus

PURPOSE

To investigate for the first time the association of collagen COL4A3 (rs55703767), COL5A1 (rs7044529), and COL4A4 (rs2229813) variants with response to corneal collagen cross-linking (CXL) with riboflavin and ultraviolet A in patients with keratoconus (KC).

METHODS

A total of 147 eligible patients with KC were genotyped for the specified collagen variants using real-time TaqMan-based polymerase chain reaction. Adjusted odds ratio (OR) with 95% confidence interval (CI) was applied to assess the strength of the association with response to CXL for a decrease in maximum keratometry and/or an increase in corneal thickness.

RESULTS

Eighty-two patients (55.8%) had post-CXL successful outcomes. The overall analysis revealed that minor allele frequencies of COL4A3, COL5A1, and COL4A4 variants were 0.22, 0.22, and 0.38, respectively. The G/T genotype of the COL4A3 variant was more prevalent in the successful group (43%) compared with the failure group (23%) (P < 0.001). COL4A3 (rs55703767) was associated with a good response under heterozygote (OR: 2.19, 95% CI, 1.04-4.59, P < 0.001) and overdominant (OR: 2.59, 95% CI, 1.25-5.38, P = 0.008) models. By contrast, COL5A1 and COL4A4 variants were not associated with the effective response after CXL treatment. Interestingly, stratification analysis by sex revealed that CXL was more successful in female patients with KC under heterozygote (OR: 4.71, 95% CI, 1.74-12.75), dominant (OR: 3.16, 95% CI, 1.29-7.78), and overdominant (OR: 5.18, 95% CI, 1.92-13.95) models for COL4A3 (rs55703767) variant.

CONCLUSIONS

The COL4A3 (rs55703767) variant, among other study variants, could be implicated in CXL riboflavin/ultraviolet A treatment response in patients with KC in the study population. Large-scale replication and follow-up studies in different ethnic groups are warranted.

Towards an understanding of the mechanoreciprocity process in adipocytes and its perturbation with aging

Adipose tissue (AT) is a complex organ, with multiple functions that are essential for maintaining metabolic health. A feature of AT is its capability to expand in response to physiological challenges, such as pregnancy and aging, and during chronic states of positive energy balance occurring throughout life. AT grows through adipogenesis and/or an increase in the size of existing adipocytes. One process that is required for healthy AT growth is the remodeling of the extracellular matrix (ECM), which is a necessary step to restore mechanical homeostasis and maintain tissue integrity and functionality. While the relationship between mechanobiology and adipogenesis is now well recognized, less is known about the role of adipocyte mechanosignaling pathways in AT growth. In this review article, we first summarize evidence linking ECM remodelling to AT expansion and how its perturbation is associated to a metabolically unhealthy phenotype. Subsequently, we highlight findings suggesting that molecules involved in the dynamic, bidirectional process (mechanoreciprocity) enabling adipocytes to sense changes in the mechanical properties of the ECM are interconnected to pathways regulating lipid metabolism. Finally, we discuss processes through which aging may influence the ability of adipocytes to appropriately respond to alterations in ECM composition.

Association of matrix metalloproteinase-2 gene polymorphisms with susceptibility to type 2 diabetes: A case control study

AIMS

Genetic variations mediating MMP-2 expression may result in individual differences in susceptibility to particular diseases. Our aim was to investigate the possible association of certain MMP-2 gene variants with the susceptibility of type 2 diabetes (T2D) in a Tunisian population.

SUBJECTS AND METHODS

A retrospective case-control study involving 310 normoglycemic control subjects and 791 T2D patients was conducted. Genotyping of MMP-2 variants was performed by real time PCR.

RESULTS

Minor allele frequencies (MAF) of the rs243865 and the rs243866 MMP-2, were significantly different between T2D cases and controls. Setting homozygous wild-type genotype carrier as reference, a reduced risk of T2D was seen with the rs243865 and the rs243866 genotypes. Haploview analysis revealed limited linkage disequilibrium between the tested MMP-2 and variants, with most haplotypes (99.5%) captured by 7 MMP-2 haplotypes. Taking the GCCC haplotype as reference for MMP-2 (OR = 1.00), a reduced frequency of TTCC haplotypes (P = 0.04) and the GTCC haplotype (P = 3.5 · 10^-5) was noted in T2D which indicates a protective nature of these two haplotypes for T2D development.

CONCLUSION

To the best of our knowledge, the present study is the first to demonstrate a consistent association of the rs243865 and rs243866 genotype with a protection for T2D.

Differential expression of COL4A3 and collagen in upward and downward progressing types of nasopharyngeal carcinoma

Upward (local growth and invasion of the base of skull), downward (distant metastasis) and mixed progressing types of nasopharyngeal carcinoma (NPC) have been identified and are distinctly different with respect to clinical symptoms, therapeutic strategies and prognosis. The present study aimed to identify the genetic difference and collagen expression levels in the upward and downward progressing types of NPC. Whole exon sequencing (WES) was used to detect genes differentially mutated between the upward and downward progressing types of NPC. Collagen deposition in the upward and downward progressing types of NPC was determined using Masson trichromatic staining, while the protein expression level of COL4A3 was detected using immunohistochemistry. Survival analysis was also performed using the Kaplan-Meier Plotter database to examine the role of COL4A3 expression level in the prognosis of head and neck squamous cell carcinoma. Knockdown of COL4A3 was performed using short interfering (si)RNA-COL4A3 in a 5-8F NPC cell line. Reverse transcription-quantitative PCR and western blot analyses were utilized to analyze the mRNA and protein expression levels of COL4A3, respectively. The roles of COL4A3 in the migration and invasion of the 5-8F cell line were examined using wound-healing Transwell and Matrigel assays, respectively. A total of 21 genes were differentially mutated between the upward and downward progressing types of NPC. The COL4A3 was investigated further, as it was found to be associated with extracellular matrix deposition and cancer metastasis. The COL4A3 gene was markedly downregulated in the downward progressing type compared with that in the upward progressing type (2.161±1.306 vs. 5.077±3.619; P<0.05). In addition, the deposition of collagen in the downward progressing type was also significantly decreased compared with that in the upward progressing type (5.63±6.83 vs. 10.94±9.60; P<0.05). Kaplan-Meier analysis indicated that high expression level of COL4A3 was positively associated with a favorable prognosis of head and neck squamous cell carcinoma (HR, 0.69; 95% CI, 0.49- 0.97; P=0.031). To confirm the role of COL4A3, the expression level of COL4A3 was knocked down using siRNA in the 5-8F cell line and the results showed that the invasion and migration was significantly increased when the expression of COL4A3 was inhibited (P<0.0001). In conclusion, the gene mutation patterns were significantly different between the upward and downward progressing types of NPC. In addition, the expression level of the COL4A3 gene was decreased in the downward progressing type, which might promote NPC metastasis through the downregulation of extracellular collagen expression.

Repairing effects of glucosamine sulfate in combination with etoricoxib on articular cartilages of patients with knee osteoarthritis

Purpose

To evaluate the repairing effects of glucosamine sulfate combined with etoricoxib on articular cartilages of patients with knee osteoarthritis (KOA).

Methods

A total of 106 KOA patients were randomly divided into control (n = 40) and experimental groups (n = 66) and treated with etoricoxib alone and glucosamine sulfate plus etoricoxib, respectively. Changes in WOMAC score and clinical efficacy were observed. The synovial fluid was extracted. Bone metabolism indices, growth factors, inflammatory factors, matrix metalloproteinases (MMPs), and NO-induced apoptosis-related factors were measured by ELISA. JNK and Wnt5a mRNA levels were determined using RT-PCR.

Results

After treatment, the total WOMAC scores of both groups significantly declined (P < 0.05), being lower in experimental group. The total effective rate of experimental group was higher (P < 0.05). BGP and OPG levels rose, especially in experimental group (P < 0.05). CTX-II, COMP, and RANKL levels decreased, particularly in experimental group (P < 0.05). TGF-β, IGF-1, and FGF-2 levels increased, especially in experimental group (P < 0.05). Both groups, particularly experimental group, had decreased levels of IL-1β, IL-17, IL-18, TNF-α, MMP-3, MMP-9, and MMP-13 (P < 0.05). JNK and Wnt5a mRNA levels of both groups dropped, which were lower in experimental group (P < 0.05). NO and LPO levels reduced, being lower in experimental group. SOD level rose, especially in experimental group (P < 0.05).

Conclusion

Glucosamine sulfate plus etoricoxib can repair the articular cartilages of KOA patients. Probably, JNK and Wnt5a are downregulated to inhibit the secretion of MMPs through lowering the levels of inflammatory factors, thereby delaying cartilage matrix degradation. NO-induced chondrocyte apoptosis may be suppressed via the SOD pathway.

Nitric Oxide Synthase 2 Polymorphisms (rs2779248T/C and rs1137933C/T) and the Risk of Type 2 Diabetes in Zahedan, Southeastern Iran

BACKGROUND

Nitric oxide (NO) has been associated with insulin resistance and type 2 diabetes (T2D). NO is synthesized enzymatically from l-arginine (l-Arg) by three NO synthase (NOS) isoforms, Neuronal NOS (nNOS or NOS1), Inducible NOS (iNOS or NOS2), and Endothelial NOS (eNOS or NOS3). The impact of NOS2 gene polymorphism was investigated on the susceptibility of T2D in a sample of Iranian population (Southeastern of Iran).

METHODS

In 2015, the present case-control study was conducted on 152 T2D patients and 157 healthy control subjects (HCs) referring to Bu-ali Hospital of Zahedan, eastern Iran. Genotyping of NOS2 rs2779248T/C and rs1137933C/T variants were done using the Tetra-Amplification Refractory Mutation System Polymerase Chain Reaction (Tetra-ARMS PCR) method.

RESULTS

CT genotype of rs1137933C/T was significantly associated with increased risk of T2D (P<0.0001). The T allele of this single nucleotide polymorphism (SNP) was also strongly associated with T2D risk (P<0.0001). For rs2779248 T/C, TC genotype of this SNP decreased the risk of T2D (OR=0.25 95%CI= 0.15-0.42, P<0.0001); however, CC genotype of this SNP increased the risk of T2D (P<0.005). There was no significant association between clinical-demographic characteristics of T2D group with respect to both SNPS in dominant.

CONCLUSION

CT genotype and C allele of NOS2 rs1137933 C/T polymorphism were associated with a higher risk of T2D, and no association was observed between T allele of NOS2 rs2779248 T/C polymorphism and T2D while TC genotype of this SNP decreased the risk of T2D in the study participants.

Associations of high-altitude polycythemia with polymorphisms in PIK3CD and COL4A3 in Tibetan populations

Background

High-altitude polycythemia (HAPC) is a chronic high-altitude disease that can lead to an increase in the production of red blood cells in the people who live in the plateau, a hypoxia environment, for a long time. The most frequent symptoms of HAPC include headache, dizziness, breathlessness, sleep disorders, and dilation of veins. Although chronic hypoxia is the main cause of HAPC, the fundamental pathophysiologic process and related molecular mechanisms responsible for its development remain largely unclear yet.

Aim/methods

This study aimed to explore the related hereditary factors of HAPC in the Chinese Han and Tibetan populations. A total of 140 patients (70 Han and 70 Tibetan) with HAPC and 60 healthy control subjects (30 Han and 30 Tibetan) were recruited for a case-control association study. To explore the genetic basis of HAPC, we investigated the association between HAPC and both phosphatidylinositol-4,5-bisphosphonate 3-kinase, catalytic subunit delta gene (PIK3CD) and collagen type IV α3 chain gene (COL4A3) in Chinese Han and Tibetan populations.

Results/conclusion

Using the unconditional logistic regression analysis and the false discovery rate (FDR) calculation, we found that eight SNPs in PIK3CD and one SNP in COL4A3 were associated with HAPC in the Tibetan population. However, in the Han population, we did not find any significant association. Our study suggested that polymorphisms in the PIK3CD and COL4A3 were correlated with susceptibility to HAPC in the Tibetan population.

Association of nitric oxide synthase 3 gene polymorphism with the risk of type 2 diabetes

Type-2 diabetes (T2D) is a multifactorial (environmental and genetic factors) and global epidemic disease with an estimated high prevalence worldwide. Studies have indicated that nitric oxide synthase 3 (NOS3) has several important roles in the pathogenesis of T2D. The present study aims to investigate the association between NOS3 rs1800779(A/G) and T2D in an Iranian sample population. A case-control study was conducted on 250 T2D patients and 250 healthy control subjects (HCs). Genotyping of the rs1800779(A/G) variant was conducted using a Tetra-Amplification Refractory Mutation System polymerase chain reaction. The frequencies of genotypes AA, AG and GG polymorphisms were 56.8, 39.2 and 4% in the T2D group, and 42.8, 56 and 1.2% in the HCs group, respectively. The frequency of the minor (G) allele was 23.6% in the T2D group and 29.2% in the HCs group. The genotype frequencies of the rs1800779(A/G) variant demonstrated statistically significant differences between T2D and controls in a codominant model (AG vs. AA, OR=0.527, 95% CI=0.368-0.756, P<0.001) and dominant model (AG+GG vs. AA, OR=0.569, 95% CI=0.399-0.811, P=0.002). There was no significant association between clinical and demographic characteristics and the NOS3 rs1800779(A/G) polymorphism in dominant status (P>0.05). The dominant model and AG genotype of NOS3 rs1800779(A/G) polymorphism may had a protective effect on T2D of Iranian population.