cells Article mTOR Signaling Pathway Regulates Sperm Quality in Older Men Joana Vieira Silva 1,2,3 , Madalena Cabral 4,Bárbara Regadas Correia 1, Pedro Carvalho 1,4, Mário Sousa 3,5, Pedro Fontes Oliveira 2,3,5 and Margarida Fardilha 1,* 1 Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine–iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal;
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[email protected] (P.C.) 2 i3S-Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal;
[email protected] 3 Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, 4050-313 Porto, Portugal;
[email protected] 4 COGE-Clínica Obstétrica e Ginecológica de Espinho, 4500-057 Espinho, Portugal;
[email protected] 5 Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, 4050-313 Porto, Portugal * Correspondence:
[email protected]; Tel.: +351-9181-43947 Received: 5 June 2019; Accepted: 19 June 2019; Published: 21 June 2019 Abstract: Understanding how age affects fertility becomes increasingly relevant as couples delay childbearing toward later stages of their lives. While the influence of maternal age on fertility is well established, the impact of paternal age is poorly characterized. Thus, this study aimed to understand the molecular mechanisms responsible for age-dependent decline in spermatozoa quality. To attain it, we evaluated the impact of male age on the activity of signaling proteins in two distinct spermatozoa populations: total spermatozoa fraction and highly motile/viable fraction.