The Correlation Of NDUFV2 And Its Single Nucleotide Polymorphism With Lumbar Disc Degeneration

BackgroundLumbar disc degeneration(LDD)refers to the physiological or pathological process of degeneration of the intervertebral disc,which is the basis of various spinal related diseases.LDD can usually lead to chronic low back pain,and a series of treatments caused by it have caused huge social and economic burden worldwide.The pathogenesis of LDD is complex.The nucleus pulposus(NP)cells play an important role in maintaining the normal function and morphology of the lumbar disc.Therefore,it is crucial to study the effects of various pathogenic factors on the NP cells of lumbar disc.Previous studies have shown that genetic factors,such as autophagy and apoptosis,could contribute to dysfunction of NP cells,further causing abnormalities of extracellular matrix,leading to degeneration of NP tissue,ultimately leading to LDD.However,there is no evidence that could show the relationship between the abnormality of mitochondrial related genes and LDD.Single nucleotide polymorphism(SNP)refers to the variation of a single nucleotide in the human genome.This genetic variation is often associated with an increase in the incidence rate of many diseases.Studies have shown that SNPs of some protein coding genes,such as collagen related genes,and metabolism related genes,such as vitamin D receptor coding genes,inflammatory factor coding genes,may be associated with the pathogenesis of LDD.However,there are no relevant studies on the relationship of LDD,the SNPs of genes related to mitochondrial and the gene expression changes caused by SNPs.Previous studies have shown that NADH dehydrogenase(ubiquinone)flavoprotein 2(NDUFV2)is the core subunit of mitochondrial respiratory chain complex I and it plays a crucial role in mitochondrial respiration.NDUFV2 can accept and accommodate electrons,and plays an important role in maintaining electron transmission and preventing electron leakage.Its abnormal expression will lead to mitochondrial respiratory dysfunction,electron leakage,and may have a significant impact on the life activities of cells.However,the effect of NDUFV2 on NP cells has not been studied yet.Therefore,this study focuses on the relationship between the mitochondrial respiration related gene NDUFV2 and the single nucleotide polymorphism of it and lumbar disc degeneration,which is of great significance.ObjectiveThe correlation of the SNPs related to NDUFV2,expression changes of NDUFV2 caused by SNPs and susceptibility of LDD was preliminary investigated.Materials and MethodsA total of 46 patients with LDD and 45 controls were recruited,and each participant provided 5ml peripheral venous blood.DNA and RNA were extracted from the blood of each participant for further genotyping.The frequency of different genotypes in the case group and control group was determined,and analysis of the risk of LDD associated with different SNP genotypes was performed.The visual analogue scale(VAS)scores of the patients’ degree of chronic low back pain were calculated,and the relationship between VAS scores and SNPs was analyzed.Bioinformatics databases were used to perform functional annotation and analysis of SNPs related to NDUFV2,and the specific mechanisms by which interested SNPs affected NDUFV2 expression were also predicted by them.Human NP cells were treated with knockdown or overexpression of the NDUFV2.Mito-tracker staining and mitochondrial membrane potential test were used to detect changes in mitochondrial function of the treated NP cells.At the same time,various experiments were performed to detect the effects of decreased or increased NDUFV2 expression on the proliferation,migration,apoptosis,and degeneration of human NP cells.ResultsAfter excluding the influence of sex,age,height,and weight on LDD,a significant association between SNP rs 145497186 related to NDUFV2 and LDD persisted(P=0.006).Simultaneously,rs145497186 was found to be associated with chronic low back pain in LDD populations.Meanwhile,bioinformatics analysis found that rs145497186 interferes with the transcription and expression of NDUFV2 by influencing transcription factor binding sites(TFBS)upstream of NDUFV2.The decreased expression of NDUFV2 in NP cells led to a significant decrease in mitochondrial function and an increase in the level of reactive oxygen species(ROS),which in turn led to a decrease in their proliferation and migration ability,as well as an increase in apoptosis and degeneration,finally resulting in LDD.Conclusion1.SNP rs145497186 related to NDUFV2 was associated with susceptibility to LDD and the degree of chronic low back pain;2.NDUFV2 rs145497186 mainly affects the TFBS of NDUFV2,thus leading to the occurrence of LDD;3.The level of NDUFV2 in the blood of patients with LDD decreased significantly;4.After down-regulating NDUFV2 in NP cells,the mitochondrial function,proliferation and migration ability of NP cells decreased significantly,the level of ROS,cell apoptosis and cell degeneration are increased,and vice versa.