Lipoperoxidation damage of spermatozoa polyunsaturated fatty acids PUFA scavenger mechanisms and possible scavenger therapies

Abstract

The lipid metabolism in sperm cells is important both as one of the main sources for energy production and for cell structure. The double leaflets of the membrane should be considered not simply as a passive lipid film, but as a very specialized structure. The complete maturation of the sperm cell membrane is attained after testicular lipid biosynthetic processes and after passage through the epididymis. A special composition of membrane phospholipids, rich in polyunsaturated fatty acids (PUFA), and the different composition of sperm and immature germ cell membrane are described and discussed.Testis germ cells as well as epididymal maturing spermatozoa are endowed with enzymatic and nonenzymatic scavenger systems to prevent lipoperoxidative damage. Catalase, superoxide dismutase and GSHdependent oxidoreductases are present in variable amounts in the different developmental stages. Phospholipid hydroperoxide GSH peroxidase (PHGPx) activity and alpha tochopherol of epididymal spermatozoa are considered in detail. Their distribution and roles in caput and cauda epididymal sperm cells are discussed.Seminal plasma also has a highly specialized scavenger system that defends the sperm membrane against lipoperoxidation and the degree of PUFA insaturation acts to achieve the same goal. Systemic predisposition and a number of pathologies can lead to an anti-oxidant/prooxidant disequilibrium. Scavengers, such as GSH, can be used to treat these cases as they can restore the physiological constitution of PUFA in the cell membrane. The results of GSH therapy are presented and discussed. PHOSPHOLIPIDS OF THE SPERM PLASMA MEMBRANE: THEIR PHYSIOLOGY AND ROLE Preliminary remarksSperm membranes play a very active role in sperm fertilization capacity and in sperm-oocyte cross talk, and its biochemical constitution is one of the main field of interest in the study of sperm physiology and pathology. Spermatozoa are polarized cells with structurally and functionally distinct domains. The two leaflets in the membrane of the cap region, overlying the acrosomal vesicle are the domains sensitive to the capacitation stimuli (1). When the various steps of capacitation have induced an increase in the fluidity of the cap region, a fusogenic process, which possesses already the structural premise, starts between this membrane and the outer acrosomal vesicle membrane. The final event consists in the formation of pores that allow a dispersion of the acrosomal enzymes acrosine and hyaluronidase. A

Germ cells and fatty acids induce translocation of CD36 scavenger receptor to the plasma membrane of Sertoli cells

“…It has been shown that cells contain relatively large amount of PUFAs, and that their distribution is not homogeneous among cell populations. Moreover, a broad change in lipid repartition between the residual body and the spermatozoan cytoplasmic membrane has been described in the literature (Retterstol et al, 2000;Lenzi et al, 2000). Within the seminiferous epithelium, Sertoli cells are very active in metabolizing PUFAs while isolated germ cells are inefficient in synthesizing 22:5n-6 and 22:6n-3 (Hurtado de Catalfo and de Gomez Dumm, 2002).…”

Resveratrol improves reproductive parameters of adult rats varicocelized in peripuberty

“…Besides, sperms have little cytoplasm and low antioxidant status, what makes them more susceptible to the effects of direct oxidative stress (Shefi & Turek 2006). The abundant concentration of PUFA and cholesterol present in the cellular membrane of mature sperms (Ko et al 2014, Mendeluk et al 2015 provides the necessary fluidity for the occurrence of the fusogenic events associated with the fertilization process (Nordberg & Arnér 2001); however, it also makes them more vulnerable to oxidative stress (Lenzi et al 2000). A high ROS production along with a reduction in the total antioxidant capacity (Tramer et al 1998) can impair the fluidity of the plasma membrane of the sperm and raise sperm DNA damage (Miyaoka & Esteves 2012).…”

Activity of antioxidant enzymes in seminal plasma and their relationship with lipid peroxidation of spermatozoa

“…Aerobic metabolism of human sperm produces various reactive oxygen species (ROS), which are potentially harmful to the sperm plasma membrane with its high content of polyunsaturated fatty acids (1)(2)(3). There is growing evidence that lipid peroxida�lini�al Urology �lini�al Urology tion damage to the plasma membrane of spermatozoa plays an important role in the mechanism of male infertility (4)(5)(6).…”