Validation of Clusterin as a potential marker to evaluate sperm quality

• Autor(a) principal: Moreira, Jéssica Leal
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/31958
• topic: Spermatozoa; Male fertility; Clusterin; Oxidative stress; Sperm DNA fragmentation

Infertility affects approximately 15% of couples in reproductive age, with half of the cases being associated with dysfunctions in men. Infertility of unknown cause is the most common type of male infertility, which may be partly explained by the shortage of diagnostic methods. The evaluation of male fertility is based largely on the basic seminal analysis. Hence, it is essential to develop new advanced tests to evaluate sperm quality and function. Sperm proteomic studies have enabled to obtain data concerning sperm protein composition in several infertility-related scenarios, revealing biomarkers that may aid in the evaluation of male fertility potential. Thereby, the main objectives of this project were to (1.) perform a systematic review of differential proteomic studies in human sperm to identify candidate targets to monitor sperm quality; and parallelly (2.) studyClusterin as a potential marker to evaluate sperm quality. The systematic literature search and qualitative review were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Twenty-five studies were included in the systematic review. From those, a panel of 15 up-regulated and 36 down-regulated proteins that could serve as potential biomarkers for sperm quality assessment was identified. Clusterin was shown to be upregulated in the sperm cells of men with increased age, type 1 and 2 diabetes, obesity, asthenozoospermia, as well as in men with idiopathic infertility, in vitro fertilization failure and poor blastocyst development. The experimental results confirmed Clusterin as being present on the cell surface of human sperm cells, but no significant differences were observed between the highly viable/motile fractions and the defective/immotile fractions in both normozoospermic and subfertile samples. However, further studies on sperm samples from individuals with infertility-related conditions need to be performed.