Altered circadian clock gene expression in the sperm of infertile men with asthenozoospermia

Effects of Sleep Disorders and Circadian Rhythm Changes on Male Reproductive Health: A Systematic Review and Meta-analysis

“…We analyzed testicular specimens from four patients with nonobstructive azoospermia (NOA) versus four patients with normal spermatogenesis and found that the clock genes (Per1, Per2, Cry2, Nr1d1 and Npas2) were significantly downregulated in NOA patients. A study by Zhang, P. et al demonstrated similar content, finding that the expression levels of five clock genes (BMAL1, Clock, CRY1, PER1 and PER2) were significantly lower in the sperm of infertile men with weak spermatozoa (AZS) than in normal fertile men (Zhang et al, 2022). Liang et al downregulated clock gene expression in male mouse testes and found lower in vitro fertilization rates in clock knockout sperm, lower blastocyst formation rates, lower acrosome enzyme activity and delayed oocyte dispersal.…”

“…The circadian clock is an endogenous mechanism that governs 24-h rhythmic variation in organism behaviour and physiology, which is regulated by a core set of clock genes that coordinate their transcriptional and translational autoregulatory feedback loops at the cellular level ( Figure 9 ). The core clock genes include Clock, Arntl, period (Per)1, Per2, Per3, cryptochrome (Cry)1, and Cry2, which are necessary for generating and maintaining circadian rhythmicity ( Boden et al, 2013 ; Li et al, 2018 ; Zhang et al, 2022 ). In recent years, there has been an increasing recognition of the importance of clock genes and circadian rhythm regulation for health; biological clock genes have been directly linked not only to sleep disorders but also to diabetes, cancer, bipolar disorder, and infertility ( Takahashi et al, 2008 ; Welsh et al, 2010 ; Hodžić et al, 2013 ; Sciarra et al, 2020 ).…”