Genetic variants within Ninjurin 2 gene are associated with risk of ischemic stroke in Iranian population

Effects of Ninjurin 2 polymorphisms on susceptibility to coronary heart disease

OBJECTIVE

The aim of this study was to explore the effects of Ninjurin 2 (NINJ2) polymorphisms on susceptibility to coronary heart disease (CHD).

METHODS

We conducted a case-control study with 499 CHD cases and 505 age and gender-matched controls. Five single nucleotide polymorphisms (SNPs) in NINJ2 (rs118050317, rs75750647, rs7307242, rs10849390, and rs11610368) were genotyped by the Agena MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression analysis to assess the association of NINJ2 polymorphisms and CHD risk-adjusted for age and gender. What's more, risk genes and molecular functions were screened via protein-protein interaction (PPI) network and functional enrichment analysis.

RESULTS

Rs118050317 in NINJ2 significantly increased CHD risk in people aged more than 60 years and women. Rs118050317 and rs7307242 had strong relationships with hypertension risk in CHD patients. Additionally, rs75750647 exceedingly raised diabetes risk in cases under multiple models, whereas rs10849390 could protect CHD patients from diabetes in allele, homozygote, and additive models. We also observed two blocks in NINJ2. Further interaction network and enrichment analysis showed that NINJ2 played a greater role in the pathogenesis and progression of CHD.

CONCLUSION

Our results suggest that NINJ2 polymorphisms are associated with CHD risk.

NINJ2 deficiency inhibits preadipocyte differentiation and promotes insulin resistance through regulating insulin signaling

OBJECTIVE

Genetic variants in ninjurin-2 (NINJ2; nerve injury-induced protein 2) confer risk of ischemic strokes and coronary artery disease as well as endothelial activation and inflammation. However, little is known about NINJ2's in vivo functions and underlying mechanisms.

METHODS

The phenotypes of NINJ2 knockout mice were analyzed, and mechanisms of NINJ2 that regulate body weight, insulin resistance, and glucose homeostasis and lipogenesis were investigated in vivo and in vitro.

RESULTS

This study found that mice lacking NINJ2 showed impaired adipogenesis, increased insulin resistance, and abnormal glucose homeostasis, all of which are risk factors for strokes and coronary artery disease. Mechanistically, NINJ2 directly interacts with insulin receptor/insulin-like growth factor 1 receptor (INSR/IGF1R), and NINJ2 knockdown can block insulin-induced mitotic clonal expansion during preadipocyte differentiation by inhibiting protein kinase B/extracellular signal-regulated kinase (AKT/ERK) signaling and by decreasing the expression of key adipocyte transcriptional regulators CCAAT/enhancer-binding protein β (C/EBP-β), C/EBP-α, and peroxisome proliferator-activated receptor γ (PPAR-γ). Furthermore, the interaction between NINJ2 and INSR/IGF1R is needed for maintaining insulin sensitivity in adipocytes and muscle via AKT and glucose transporter type 4. Notably, adenovirus-mediated NINJ2 overexpression can ameliorate diet-induced insulin resistance in mice.

CONCLUSIONS

In conclusion, these findings reveal NINJ2 as an important new facilitator of insulin receptors, and the authors propose a unique regulatory mechanism between insulin signaling, adipogenesis, and insulin resistance.

Involvement of NINJ2 Protein in Inflammation and Blood-Brain Barrier Transmigration of Monocytes in Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory neurodegenerative disorder of the central nervous system (CNS). The migration of immune cells into the CNS is essential for its development, and plasma membrane molecules play an important role in triggering and maintaining the inflammation. We previously identified ninjurin2, a plasma membrane protein encoded by NINJ2 gene, as involved in the occurrence of relapse under Interferon-β treatment in MS patients. The aim of the present study was to investigate the involvement of NINJ2 in inflammatory conditions and in the migration of monocytes through the blood-brain barrier (BBB). We observed that NINJ2 is downregulated in monocytes and in THP-1 cells after stimulation with the pro-inflammatory cytokine LPS, while in hCMEC/D3 cells, which represent a surrogate of the BBB, LPS stimulation increases its expression. We set up a transmigration assay using an hCMEC/D3 transwell-based model, finding a higher transmigration rate of monocytes from MS subjects compared to healthy controls (HCs) in the case of an activated hCMEC/D3 monolayer. Moreover, a positive correlation between NINJ2 expression in monocytes and monocyte migration rate was observed. Overall, our results suggest that ninjurin2 could be involved in the transmigration of immune cells into the CNS in pro-inflammatory conditions. Further experiments are needed to elucidate the exact molecular mechanisms.

Association between genetic variants and risk of obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a complex multi-gene disorder. In the current study, we genotyped six single nucleotide polymorphisms (SNPs) within MOCOS, NINJ2 and AKT1 genes in a cohort of Iranian patients with this disorder and healthy controls. C allele of rs1057251 has been found to increase risk of OCD (OR (95% CI) =6.39 (4.64-8.79), P value <0.001). This SNP has been associated with risk of OCD in codominant model (OR (95% CI) = 69.53 (25.02-193.21) and 147 (34.2-631.75) for TC and CC genotypes, respectively, P value <0.0001). The rs1057251 was also associated with risk of OCD in dominant (OR (95% CI) = 72.87 (26.28-202.03), P value <0.0001), recessive (OR (95% CI) = 7.43 (2.49-22.19), P value =0.0002), overdominant (OR (95% CI) = 20.2 (11.1-36.76), P value <0.0001) and log-additive (OR (95% CI) = 20.87 (13.83-56.14), P value <0.0001) models. The rs3809263 within NINJ2 was also associated with risk of OCD. The A allele of this SNP has been found to confer risk of OCD (OR (95% CI) =3.28 (2.41-4.48), P value <0.001). This SNP was associated with risk of OCD in codominant (P value <0.0001), dominant (P value <0.0001), overdominant (OR (95% CI) = 9.28 (5.23-16.46), P value<0.0001) and log-additive (OR (95% CI) = 5.25 (3.4-8.1), P value <0.0001) models. Other SNPs were not associated with risk of OCD in any inheritance model. Taken together, rs1057251 and rs3809263 can be considered as risk loci for OCD in Iranian population.

SLC17A3 rs9379800 and Ischemic Stroke Susceptibility at the Northern Region of Malaysia

OBJECTIVES

The relationships of Paired Like Homeodomain 2 (PITX2), Ninjurin 2 (NINJ2), TWIST-Related Protein 1 (TWIST1), Ras Interacting Protein 1 (Rasip1), Solute Carrier Family 17 Member 3 (SLC17A3), Methylmalonyl Co-A Mutase (MUT) and Fer3 Like BHLH Transcription Factor (FERD3L) polymorphisms and gene expression with ischemic stroke have yet to be determined in Malaysia. Hence, this study aimed to explore the associations of single nucleotide polymorphisms (SNPs) and gene expression with ischemic stroke risk among population who resided at the Northern region of Malaysia.

MATERIALS AND METHODS

Study subjects including 216 ischemic stroke patients and 203 healthy controls were recruited upon obtaining ethical clearance. SNP genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism assays. Gene expression levels were quantified by real-time polymerase chain reaction assays. Statistical and genetic analyses were conducted with SPSS version 22.2, PLINK version 1.07 and multifactor dimensionality reduction software.

RESULTS

Study subjects with G allele, CG or GG genotypes of SLC17A3 rs9379800 demonstrated increased risk of ischemic stroke with the odds ratios ranging from 1.76-fold to 3.14-fold (p<0.05). When stratified study subjects according to the ethnicity, SLC17A3 rs9379800 G allele and CG genotype contributed to 2.14- and 2.96-fold of ischemic stroke risk among Malay population significantly, in the multivariate analysis (p<0.05). However, no significant associations were observed for PITX2, NINJ2, TWIST1, Rasip1, and MUT polymorphisms with ischemic stroke risk in the multivariate analysis for the pooled cases and controls as well as when stratified them according to the ethnicity. Lower mRNA expression levels of Rasip1, SLC17A3, MUT and FERD3L were observed among cases (p<0.05). After FDR adjustment, the mRNA level of SLC17A3 remained significantly associated with ischemic stroke among Malay population (q=0.034).

CONCLUSION

In conclusion, this study suggests that SLC17A3 rs9379800 polymorphism and its gene expression contribute to significant ischemic stroke risk among Malaysian population, particularly the Malay who resided at the Northern Region of the country. Our findings can provide useful information for the future diagnosis, management and treatment of ischemic stroke patients.

Expression profiles of the internal jugular and saphenous veins: Focus on hemostasis genes

INTRODUCTION

Venous bed specificity could contribute to differential vulnerability to thrombus formation, and is potentially reflected in mRNA profiles.

MATERIALS AND METHODS

Microarray-based transcriptome analysis in wall and valve specimens from internal jugular (IJV) and saphenous (SV) veins collected during IJV surgical reconstruction in patients with impaired brain outflow. Multiplex antigenic assay in paired jugular and peripheral plasma samples.

RESULTS

Most of the top differentially expressed transcripts have been previously associated with both vascular and neurological disorders. Large expression differences of HOX genes, organ patterning regulators, pinpointed the vein positional identity. The "complement and coagulation cascade" emerged among enriched pathways. In IJV, upregulation of genes for coagulation inhibitors (TFPI, PROS1), activated protein C pathway receptors (THBD, PROCR), fibrinolysis activators (PLAT, PLAUR), and downregulation of the fibrinolysis inhibitor (SERPINE1) and of contact/amplification pathway genes (F11, F12), would be compatible with a thromboprotective profile in respect to SV. Further, in SV valve the prothrombinase complex genes (F5, F2) were up-regulated and the VWF showed the highest expression. Differential expression of several VWF regulators (ABO, ST3GAL4, SCARA5, CLEC4M) was also observed. Among other differentially expressed hemostasis-related genes, heparanase (HPSE)/heparanase inhibitor (HPSE2) were up-/down-regulated in IJV, which might support procoagulant features and disease conditions. The jugular plasma levels of several proteins, encoded by differentially expressed genes, were lower and highly correlated with peripheral levels.

CONCLUSIONS

The IJV and SV rely on differential expression of many hemostasis and hemostasis-related genes to balance local hemostasis, potentially related to differences in vulnerability to thrombosis.

Assessment of Association between NINJ2 Polymorphisms and Suicide Attempts in an Iranian Population

Suicidal behavior as a psychological problem with high public health burden is associated with a number of genetically determined risk factors. In the current study, we investigated the association between two polymorphisms within the NINJ2 gene and risk of suicide in an Iranian population. The study included 295 individuals who attempted suicide with soft suicide methods, 234 suicide victims and 410 normal controls. The rs11833579 SNP was associated with death from suicide in a codominant model in that the AG genotype decreased the risk of death from suicide compared with the GG genotype (OR (95% CI) = 0.49 (0.34-0.71), adjusted P value = 4e-04). This SNP was also associated with death from suicide in dominant (AG + AA versus GG: OR (95% CI) = 0.63 (0.46-0.87), adjusted P value = 0.011) and overdominant (AG versus GG + AA: OR (95% CI) = 0.49 (0.35-0.69), adjusted P value < 0.0001) models. In addition, this SNP was associated with soft suicide attempts in a codominant model (AG versus AA + GG: OR (95% CI) = 0.7 (0.5-0.98), adjusted P value = 0.02). The rs3806263 SNP was associated with death from suicide in allelic (A versus G: OR (95% CI) = 1.48 (1.17-1.88), adjusted P value = 0.002), codominant (AA versus GG: OR (95% CI) = 3.14 (1.89-5.21), adjusted P value < 0.0001), recessive (AA versus GG + AG: OR (95% CI) = 3.47 (2.15-5.61), adjusted P value < 0.0001), overdominant (AG versus AA + GG: OR (95% CI) = 0.62 (0.45-0.87), adjusted P value = 0.0092) and log-additive models (OR (95% CI) = 1.45 (1.15-1.83), adjusted P value = 0.0034). When comparing allele/genotype frequencies of this SNP between suicide victims and soft suicide attempters, significant associations were found in allelic, codominant, recessive and log-additive models. The AG haplotype (rs11833579 and rs3806263, respectively) was significantly less prevalent among suicide victims compared with controls (OR (95% CI) = 0.37 (0.26-0.52), adjusted P value < 0.0001). This haplotype was also less prevalent among suicide victims vs. soft suicide attempters (OR (95% CI) = 0.43 (0.31-0.61), adjusted P value < 0.0001). The GA haplotype (rs11833579 and rs3806263, respectively) was less frequent among suicide victims compared with controls (OR (95% CI) = 0.63 (0.45-0.89), adjusted P value = 0.0156). Finally, the AA haplotype was more prevalent among suicide victims compared with both controls (OR (95% CI) = 2.37 (1.56-3.6), adjusted P value = 0.0002) and soft suicide attempters (OR (95% CI) = 1.92 (1.32-2.78), adjusted P value = 0.0012). Thus, these two SNPs might be regarded as genetic determinants of suicide risk in Iranian populations. Further studies in different populations are needed to verify these results.

Associations Between Two Single-Nucleotide Polymorphisms in NINJ2 Gene and Risk of Psychiatric Disorders

NINJ2 encodes a transmembrane protein that contributes in neurodevelopment and regeneration of neurons. Single-nucleotide polymorphisms (SNPs) within this gene have been associated with Alzheimer's disease, ischemic stroke, and multiple sclerosis. The rs11833579 and rs3809263 SNPs have been associated with risk of ischemic stroke in Iranian population. While the NINJ2 rs12425791 has been with risk of ischemic stroke in East Asian population, the rs11833579 has not been associated with this condition either in East Asian population or Chinese Han population. In the current project, we genotyped rs11833579 and rs3809263 in a large cohort of neuropsychiatric patients including major depressive disorder, bipolar disorder, schizophrenia, and methamphetamine addiction. No significant difference was detected in frequencies of alleles, genotypes, or haplotypes between patients and controls. Thus, the current investigation failed to show association between rs11833579 and rs3809263 and the mentioned neuropsychiatric disorders. Future studies are needed to verify our results.