Association between the single nucleotide variants of the mitochondrial cytochrome B gene (MT-CYB) and the male infertility

Background Idiopathic male infertility can be attributed to genetic predispositions that afect sperm performance and function. Genetic alterations in the mitochondrial DNA (mtDNA) have been linked to certain types of male infertility and abnormal sperm function. Mutations in the mitochondrial cytochrome B (MT-CYB) gene might lead to some defciencies in mitochondrial function. Thus, in the current study, we aimed to investigate the efect of mutations in the MT-CYB gene on sperm motility and male infertility. Methods and results Semen specimens were collected from 111 men where 67 men were subfertile and 44 were fertile. QIAamp DNA Mini Kit and REPLI-g Mitochondrial DNA Kit from QIAGEN were used to isolate and amplify the mito chondrial DNA. Followed by PCR and Sanger sequencing for the target sequence in the MT-CYP gene. Sequencing of the MT-CYB gene revealed a total of thirteen single nucleotide polymorphisms (SNPs). Eight SNPs were non-synonymous vari ant (missense variant) including: rs2853508, rs28357685, rs41518645, rs2853507, rs28357376, rs35070048, rs2853506, and rs28660155. While fve SNPs were Synonymous variant: rs527236194, rs28357373, rs28357369, rs41504845, and rs2854124. Among these SNPs, three variants showed a signifcant diference in the frequency of the genotypes between subfertile and fertile groups: rs527236194 (T15784C) (P=0.0005), rs28357373 (T15629C) (P=0.0439), and rs41504845 (C15833T) (P=0.0038). Moreover, two SNPs showed a signifcant association between allelic frequencies of rs527236194 (T15784C) (P=0.0014) and rs41504845 (C15833T) (P=0.0147) and male subfertility. Conclusion The current study showed a signifcant association between the MT-CYB gene polymorphisms and the develop ment of male infertility. In particular, rs527236194, rs28357373 and rs41504845 variants were found to be the most related to the subfertility group. Further studies on larger and other populations are required to reveal the exact role of this gene in the development of male infertility. In addition, functional studies will be helpful to elucidate the molecular impact of the MT-CYP polymorphisms on mitochondrial function

Impact of tobacco smoking in association with H2BFWT, PRM1 and PRM2 genes variants on male infertility

Tobacco's genotoxic components can cause a wide range of gene defects in spermatozoa such as single- or double-strand DNA breaks, cross-links, DNA-adducts, higher frequencies of aneuploidy and chromosomal abnormalities. The aim in this study was to determine the correlation between sperm quality determined by standard parameters, sperm DNA maturity tested by Chromomycin A3 (CMA3) staining, sperm DNA fragmentation tested by TUNEL assay and tobacco smoking in association with the single nucleotides polymorphisms (SNP) of three nuclear protein genes in spermatozoa (H2BFWT, PRM1 and PRM2). In this study, semen samples of 167 male patients were collected and divided into 54 non-smokers and 113 smokers. The target sequences in the extracted sperm DNA were amplified by PCR followed by Sanger sequencing. The results showed the presence of three variants: rs7885967, rs553509 and rs578953 in H2BFWT gene in the study population. Only one variant rs737008 was detected in PRM1 gene, and three variants were detected in the PRM2 gene: rs2070923, rs1646022 and rs424908. No significant association was observed between the concentration, progressive motility, morphology and the occurrence of H2BFWT, PRM1 and PRM2 SNPs. However, sperm parameters were significantly lower in heavy smokers compared to controls (p < 0.01) (sperm count: 46.00 vs. 78.50 mill/ml, progressive motility: 15.00% vs. 22.00%, and morphology 4.00% vs. 5.00%, respectively). Moreover, the heavy smoker individuals exhibited a considerable increase in CMA3 positivity and sDF compared to non-smokers (p < 0.01) (29.50% vs. 20.50% and 24.50% vs. 12.00%, respectively). In conclusion, smoking altered sperm parameters and sperm DNA integrity, but did not show a linkage with genetic variants in H2BFWT, and protamine genes (PRM1 and PRM2)

Lack of association between single polymorphic variants of the mitochondrial nicotinamide adenine dinucleotide dehydrogenase 3, and 4L (MT-ND3 and MT-ND4L) and male infertility

Male infertility is a multifactorial condition associated with different genetic abnormalities in at least 15%–30% of cases. The purpose of this study was to identify suspected correlations between infertility and polymorphisms in mitochondrial NADH dehydrogenase subunits 3 and 4L (MT-ND3 and MT-ND4L) in subfertile male spermatozoa. Sanger sequencing of the mitochondrial DNA target genes was performed on 68 subfertile and 44 fertile males. Eight single nucleotide polymorphisms (SNPs) in MT-ND3 (rs2853826, rs28435660, rs193302927, rs28358278, rs41467651, rs3899188, rs28358277 and rs28673954) and seven SNPs in MT-ND4L (rs28358280, rs28358281, rs28358279, rs2853487, rs2853488, rs193302933 and rs28532881) were detected and genotyped. The genotypes and allele frequencies of the study population have shown a lack of statistically significant association between MT-ND3 and MT-ND4L SNPs and male infertility. However, no statistically significant association was found between the asthenozoospermia, oligozoospermia, teratozoospermia, asthenoteratozoospermia, oligoasthenoteratozoospermia and oligoteratozoospermia subgroups of subfertile males. However, rs28358278 genotype of the MT-ND3 gene was reported in the subfertile group but not in the fertile group, which implies a possible role of this SNP in male infertility. In conclusion, the investigated polymorphic variants in the MT-ND3 and MT-ND4L genes did not show any significant association with the occurrence of male infertility. Further studies are required to evaluate these findings. Moreover, the subfertile individuals who exhibit a polymorphism at rs28358278 require further monitoring and evaluation

Mitochondrial nicotinamide adenine dinucleotide hydride dehydrogenase (NADH) subunit 4 (MTND4) polymorphisms and their association with male infertility

Purpose The purpose of the present study was to determine the relationship between infertility and the polymorphisms of mitochondrial NADH dehydrogenase subunit 4 (MTND4) by spermatozoa analysis in fertile and subfertile men. Methods Samples were divided into 68 subfertile men (case group) and 44 fertile men (control group). After semen analysis, samples were purified. The whole genome was extracted using a QIAamp DNA Mini Kit and the mitochondrial DNA was amplified by using the REPLI-g Mitochondrial DNA Kit. Polymerase chain reaction (PCR) was used to amplify the MT-ND4 gene. Then, samples were purified and sequenced using the Sanger method. Results Twenty-five single-nucleotide polymorphisms (SNPs) were identified in the MTND4 gene. The genotype frequencies of the study population showed a statistically significant association between rs2853495 G>A (Gly320Gly) and male infertility (P = 0.0351). Similarly, the allele frequency test showed that rs2853495 G>A (Gly320Gly) and rs869096886 A>G (Leu164Leu) were significantly associated with male infertility (adjusted OR = 2.616, 95% CI = 1.374–4.983, P = 0.002; adjusted OR = 2.237, 95% CI = 1.245–4.017, P = 0.007, respectively). Conclusion In conclusion, our findings suggested that male infertility was correlated with rs2853495 and rs869096886 SNPs in MTND4

A lack of a definite correlation between male sub-fertility and single nucleotide polymorphisms in sperm mitochondrial genes MT-CO3, MT-ATP6 and MT-ATP8

Background An inability of a man to conceive a potentially fertile woman after a year of unprotected intercourse is defned as male infertility. It is reported that 30–40% of males in their reproductive years have abnormalities in sperm production, either qualitatively or quantitatively, or both. However, genetic factors result in up to 15% of male infertility cases. The present study aimed to analyze the possible correlations between sub-fertility and polymorphisms in sperm mitochondrial CO3, ATP6 and ATP8 genes in sub-fertile men. Methods and results For 67 sub-fertile and 44 fertile male samples, Sanger sequencing of selected mitochondrial DNA genes was done. A total of twelve SNPs in the MT-CO3 gene: rs2248727, rs7520428, rs3134801, rs9743, rs28358272, rs2853824, rs2856985, rs2854139, rs41347846, rs28380140, rs3902407, and 28,411,821, fourteen SNPs in the MT-ATP6: rs2001031, rs2000975, rs2298011, rs7520428, rs9645429, rs112660509, rs6650105, rs6594033, rs6594034, rs6594035, rs3020563, rs28358887, rs2096044, and rs9283154, and ten SNPs in the MT-ATP8: rs9285835, rs9285836, rs9283154, rs8179289, rs121434446, rs1116906, rs2153588, rs1116905, rs1116907, and rs3020563 were detected in the case and control groups at diferent nucleotide positions. Only the rs7520428 in the MT-CO3 and MT-ATP6 showed a statistically signifcant diference between sub-fertile and fertile groups in the genotype’s and allele’s frequency test (P<0.0001 for both). Conclusion The results of our study suggest that male sub-fertility is linked with rs7520428 SNP in MT-CO3 and MT-ATP6. The studied polymorphic variations in the MT-ATP8 gene, on the contrary, did not reveal any signifcant association with male sub-fertility

Assessment of Pathogenic Potential, Virulent Genes Profile, and Antibiotic Susceptibility of Proteus mirabilis from Urinary Tract Infection

Proteus mirabilis is the third most common bacterium that can cause complicated UTI, especially in catheterized patients. Urovirulence genes of P. mirabilis strains are poorly identified among UTI patients. The aims of the present study were to determine the prevalence of the uropathogenic P. mirabilis strains isolated from UTI patients by the detection of several P. mirabilis virulence genes and to characterize the antibiotic susceptibility profile of P. mirabilis isolates. P. mirabilis isolates were collected from urine specimens of patients suffering from UTI. Virulence genes in P. mirabilis, namely, hpmA, hpmB, rsbA, luxS, ureC1, hlyA, rpoA, atfA, atfC, mrpA, and pm1 were detected in the isolates via PCR detection method. All P. mirabilis virulence genes were detected in more than 90% of the isolates except hlyA gene, which was detected in only 23.8% of the isolates. The rate of susceptibility for ceftriaxone was 96.8%, followed by norfloxacin (82.5%), gentamicin (71.4%), ciprofloxacin (69.8%), cephalexin (52.4%), nalidixic acid (42.9%), sulfamethoxazole (39.7%), ampicillin (36.5%), and nitrofurantoin (3.2%). Significant associations (P<0.05) were detected between antimicrobial susceptibility of each of the following antibiotics and the presence virulence genes. Cephalexin antimicrobial susceptibility was significantly associated with the presence each of ureC1 and atfC. Sulfamethoxazole antimicrobial susceptibility was significantly associated with the presence atfA. Ceftriaxone antimicrobial susceptibility was significantly associated with the presence each of hpmA, ureC1, rpoA, atfC, mrpA, and pm1. Nitrofurantoin antimicrobial susceptibility was significantly associated with the presence each of hpmA, ureC1, rpoA, atfA, atfC, mrpA, and pm1. In conclusion, an association between the presence of urovirulence genes of P. mirabilis and increasing P. mirabilis resistance to antimicrobials has been demonstrated