Functional analysis of the antisense long noncoding RNA ANO1-AS2 and the ANO1 gene in Iraqi men with idiopathic infertility

The leading causes of male infertility remain unclear. Men with average semen analysis results are diagnosed with idiopathic infertility. The ANO1-AS2 gene is a long noncoding RNA located close to the anoctamin1 (ANO1) gene. ANO1 regulates calcium-activated chloride channels, which regulate many cellular processes. In this study, we aimed to evaluate the relationships between ANO1-AS2 and ANO1 expression in men with idiopathic infertility. ANO1-AS2 and ANO1 expression was evaluated in sperm samples from 50 men with idiopathic infertility and 50 fertile men. Quantitative real-time polymerase chain reaction was used to analyse the sperm samples. The results showed that ANO1 expression was significantly higher than ANO1-AS2 expression (p = 0.0001). Moreover, there was a positive correlation between ANO1 mRNA levels and sperm motility (p < 0.001; r = 0.7189). Conversely, a significant negative correlation was found between ANO1-AS2 levels and sperm motility (p < 0.003; r = -0.4068). ANO1 mRNA levels were also negatively correlated with abnormal sperm morphology (p < 0.0137; r = -0.3464), whereas ANO1-AS2 levels were positively correlated with abnormal sperm morphology (p < 0.0127; r = 0.350). The observed inverse relationship between ANO1-AS2 and ANO1 expression indicated that ANO1-AS2 may play a role in ANO1 downregulation. However, the expression of both genes was not related to the cause of idiopathic infertility in men in average semen analysis. Further studies are needed to determine the potential correlation between male infertility and ANO1-AS2 in other ethnic groups and types of infertility.