Aleksandra Nestorovic

Sperm chromatin compaction in the sperm head is achieved when histones are replaced by protamines during spermatogenesis. Haploinsufficiency of the protamine 1 (PRM1) or PRM2 gene causes infertility in mice. However, the published data remain inconclusive about a role of PRM1/2 variants in male infertility and their association with semen parameters. By full sequence analysis, we assessed the frequency of sequence variations in PRM1 and PRM2 in three groups of Caucasian patients with idiopathic teratozoospermia and normal (n = 88) or reduced sperm concentration (n = 83) and in men with a high percentage of normal sperm morphology and normal concentrations (n = 77). Two rare (c.54G>A and c.102G>T) and one common SNP (c.230A>C) were identified in PRM1. In PRM2, some rare heterozygous mutations and the two common intronic SNPs 298G>C and 373C>A were detected. None of the PRM1/2 variants was associated with teratozoospermia or individually with other semen parameters. However, significant linkage disequilibrium was detected between the common SNPs of PRM1 and PRM2 which formed haplotypes. Analysis of the pooled group (n = 248) revealed that homozygous carriers of the common haplotype ACC had a twofold higher sperm concentration and count than men lacking this haplotype, with sperm counts of heterozygotes for ACC being midway between the homozygotes. This markedly decreased sperm output might either be caused by spermatozoa lacking the ACC haplotype not being viable, or subject to negative selection. In addition, a significant deviation from Hardy-Weinberg-Equilibrium of these SNPs might indicate natural selection in favour of the ACC allele which leads to higher sperm output and therefore better fertility. In conclusion, for the first time we describe an association of a common haplotype formed by PRM1 and PRM2 with sperm output in a large group of men.

Chronic obstructive pulmonary disease (COPD) and lung cancer (LC) are a major cause of morbidity and mortality worldwide. In both diseases airways inflammation plays an important role. Functional promoter polymorphism, at the position -308, of tumor necrosis factor (TNF)-alpha represents attractive potential susceptibilty marker for both diseases. In order to investigate the role of this polymorphism in COPD and LC, a case-control study was performed. The patient groups consisted of 97 subjects with COPD and 70 subjects with LC, while the control group encompassed 102 subjects. Results of our study showed significant decrease of heterozygote for TNF-alpha-308 1/2 gene variant in COPD group in comparison to controls (p=0.043). According to our results heterozygous carriers of TNF-alpha-308 1/2 polymorphism had a2.3-fold decreased risk for COPD development (OR=0.44, 95%CI=0.20-0.97). In patients with lung cancer we also observed a trend of decreased distribution of TNF-alpha-308 1/2 heterozygotes, but statistical significance was not achieved. To our knowledge, this is the first study implicating decreased frequency of TNF-alpha-308 1/2 gene variant in patients with COPD and LC. Although these results need to be confirmed on larger cohort, they represent anew and interesting finding, not reported in other populations tested so far.