Carrageta 2018 MiP2018
Infertility is an increasing worldwide health concern that affects primarily developed countries due to the current lifestyle based on sedentarism and overconsumption of high-energy foods. In fact, during the last decades fertility rates decreased to unprecedent values. Overall infertility cases, 50% are attributed to male factors, including the decline of semen quality. One common factor concerns the reduced motility and viability, which may arise from an impaired mitochondrial function. Thus, it is pivotal to unveil mitochondrial physiology and function in sperm cells. Several signalling pathways are known to modulate mitochondrial function in distinct cells and organs though little is known concerning their role in sperm.
Recently, sirtuins (SIRT) have arisen as key metabolic sensors for body homeostasis. Several works have emphasized the relevance of SIRT1 and SIRT3 in the control of male fertility potential, namely its contribution to Sertoli cells function and hence spermatogenesis. However, to date few studies have questioned the involvement of the SIRT family in mature human spermatozoa metabolism, which can directly impact male fertility. In addition, there is an interplay between these sirtuins and mitochondrial function, a subject that has been overlooked concerning sperm physiology. In this project, we studied the presence and role of SIRT1 and SIRT3 in human sperm cells metabolism/bioenergetics. We were able to identify for the first time the presence of SIRT1 and SIRT3 in human spermatozoa by immunocytochemistry techniques. SIRT1 and SIRT3 activation or inhibition was chemically induced and spermatozoa motility and viability were evaluated. Then, spermatozoa metabolic performance and bioenergetics were determined. Our results showed that activation of both, SIRT1 and SIRT3, did not induced any cytotoxicity in sperm cells. Interestingly, activation of SIRT1 promoted the maintenance of sperm cells motility over time while activation of SIRT3 increased sperm viability. Our preliminary results showed that SIRT3 is a regulator of spermatozoa mitochondrial functioning. Activation of SIRT3 increased maximum respiration and proton leak on spermatozoa. In addition, ATP turnover by spermatozoa was also altered, thus illustrating that SIRT3 is a key regulator of spermatozoa bioenergetics. Herein, we describe the first evidence of the presence of SIRT1 and SIRT3 in human sperm cells and its effects on spermatozoa bioenergetics. Our results demonstrate that SIRT1 and SIRT3 have an active role in human spermatozoa bioenergetics and may represent an interesting target for further studies focused on therapeutic approaches for men facing subfertility or infertility.
• Bioblast editor: Plangger M
Labels: MiParea: Respiration, Developmental biology
Organism: Human Tissue;cell: Genital
Carrageta DF(1), Silva AM(1), Alves CL(1), Almeida SP(1), Sousa M(1,4), Barros A(3,4), Alves MG(1), Oliveira PF(1,2,3)
- Dept Microscopy, Lab Cell Biology, Inst Biomedical Sciences Abel Salazar and Unit Multidisciplinary Research Biomedicine
- Dept Genetics, Fac Medicine
- Inst Investigação e Inovação em Saúde; Univ Porto
- Centre Reproductive Genetics Prof. Alberto Barros; Porto, Portugal. - firstname.lastname@example.org