Are TRP channels involved in sperm development and function?

Abstract

Spermatozoa must translate information from their environment and the egg to achieve fertilization in sexually reproducing animals. These tasks require decoding a variety of signals in the form of intracellular Ca(2+) changes. As TRP channels constitute a large family of versatile multi-signal transducers, they are interesting subjects in which to explore their possible participation in sperm function. Here, we review the evidence for their presence and involvement in sperm motility, maturation, and the acrosome reaction, an exocytotic process required for sperm-egg fusion. Since store-operated Ca(2+) entry (SOCE) has been proposed to play an important role in these three functions, the main proteins responsible for this transport (STIM and ORAI) and their interaction with TRPs are also discussed. Improving our tools to solve infertility, improve animal breeding, and preserve biodiversity requires a better understanding of how Ca(2+) is regulated in spermatozoa.

Transient receptor potential-canonical 3 modulates sperm motility and capacitation-associated protein tyrosine phosphorylation via [Ca<sup>2+</sup>]<sub>i</sub> mobilization

“…Here, we adopted a pharmacological approach to characterize the exact function of TRPC3, one member of the TRPC family, in sperm motility and capacitation. Consistent with previous findings [26,28], we confirmed that TRPC3 is located on the flagellum; however, we showed that TRPC3 only localizes to the mid-piece of sperm. These inconsistent results may be due to the differences in the sensitivity and specificity of the antibodies used in each study.…”

“…The functions of multiple types of Ca 2+ channels in sperm have also been documented [19]. Previous studies using the TRPC inhibitor SKF96365 demonstrated that the members of the TRPC family play an important role in sperm motility [26][27][28]. Here, we adopted a pharmacological approach to characterize the exact function of TRPC3, one member of the TRPC family, in sperm motility and capacitation.…”

“…These channels play important roles by modulating Ca 2+ signaling during various biological processes, including male fertility [22][23][24][25]. Recently, TRPC3 has been demonstrated to be present in sea urchin [26], mouse [27], and human [28] sperm. A previous report showed that SKF96365, an inhibitor of the TRPC family, reduces human sperm motility in a dose-and time-dependent manner [28], indicating that TRPCs play an important role in sperm motility.…”

Progesterone-induced Acrosome Exocytosis Requires Sequential Involvement of Calcium-independent Phospholipase A2β (iPLA2β) and Group X Secreted Phospholipase A2 (sPLA2)

“…It is accepted that the main targets of Ca 2ϩ are specific calcium-binding proteins such as synaptotagmin (8,9), even if Ca 2ϩ also activates calmodulin-dependent enzymes such as PI3K, whose inactivation blocks the AR (10). Numerous agonist-dependent actors involved in [Ca 2ϩ ] increase have been characterized, including Ca 2ϩ influx through activation of voltage-dependent calcium channels and store-operated channels and calcium release from the acrosome itself through activation of PLC␦4 and the inositol 1,4,5-trisphosphate receptor (2,(11)(12)(13). Contrary to neuronal exocytosis where [Ca 2ϩ ] increase is followed within milliseconds by degranulation, sperm granule exocytosis spreads over 30 min in the presence of the agonists.…”

Cl− Channels and Transporters in Sperm Physiology

“…Evidence indicates internal Ca 2+ stores (i.e., the acrosome) participate releasing Ca 2+ through the IP3 receptor, the second type of Ca 2+ channel involved in the AR, which is activated as a consequence of IP3 production during the AR Florman et al 2008 ;Mayorga et al 2007 ;Publicover et al 2007 (Costello et al 2009 ;Darszon et al 2012 ).…”