miR-26a is Involved in Glycometabolism and Affects Boar Sperm Viability by Targeting PDHX

Abstract

miR-26a is associated with sperm metabolism and can affect sperm motility and apoptosis. However, how miR-26a affects sperm motility remains largely unknown. Our previous study indicated that the PDHX gene is predicted to be a potential target of miR-26a, which is responsible for pyruvate oxidative decarboxylation which is considered as a key step for connecting glycolysis with oxidative phosphorylation. In this study, we first reported a potential relationship between miR-26a and PDHX and their expressions in fresh, frozen-thawed, and epididymal boar sperm. Then, sperm viability and survival were determined after transfection of miR-26a. mRNA and protein expression level of PDHX in the liquid-preserved boar sperm after transfection were also determined by RT-qPCR and Western Blot (WB). Our results showed that expression level of PDHX was significantly increased during sperm transit from epididymal caput to corpus and cauda. Similarly, expression of PDHX was significantly higher (P < 0.05) in fresh sperm as compared to epididymal cauda and frozen-thawed sperm. However, the expression of miR-26a in epididymal corpus sperm was significantly higher (P < 0.05) than that of caput and cauda sperm. Furthermore, after transfection of boar sperm with miR-26a mimic and inhibitor under liquid storage, the lowest and highest sperm viability was observed in miR-26a mimic and inhibitor treatment (P < 0.05), respectively. The protein levels of PDHX, after 24 and 48 h of transfection of miR-26a mimics and inhibitor, were notably decreased and increased (P < 0.05), respectively, as compared to negative control (NC) group. In conclusion, the novel and enticing findings of our study provide a reasonable evidence that miR-26a via PDHX, a link between glycolysis and oxidative phosphorylation, could regulate the glycometabolic pathway which eventually affect boar sperm viability and survival.

Decreased piRNAs in Infertile Semen Are Related to Downregulation of Sperm MitoPLD Expression

“…These results suggest that the critical role and function of piRNAs during spermatogenesis process has been well documented, whether piRNAs in sperm may regulate sperm motility remain largely unknown. Increasing studies have shown that miRNAs expressed in mature sperm could regulate sperm motility ( 25 , 26 ). In contrast to miRNAs, piRNAs were just discovered in 2006, and the biogenesis and functions remain largely unexplored.…”

miR‐130a promotes immature porcine Sertoli cell growth by activating SMAD5 through the TGF‐β‐PI3K/AKT signaling pathway

“…8 Further, miR-26a promotes boar sperm viability and survival by targeting the pyruvate dehydrogenase complex component X gene through the glycometabolic pathway. 32 However, it is essential to gain additional insights into the roles of miRNAs in porcine Sertoli cell proliferation. Therefore, in this study, we detected the effect of 60 miRNAs on porcine Sertoli cell proliferation using EdU-based high-content screening assays.…”

“…Moreover, miR‐762 promotes porcine immature Sertoli cell growth by targeting the ring finger protein 4 gene 8 . Further, miR‐26a promotes boar sperm viability and survival by targeting the pyruvate dehydrogenase complex component X gene through the glycometabolic pathway 32 . However, it is essential to gain additional insights into the roles of miRNAs in porcine Sertoli cell proliferation.…”

Transcriptome-wide m6A profiling reveals mRNA post-transcriptional modification of boar sperm during cryopreservation

“…Before total RNA extraction, seminal plasma was removed by centrifuged for 5 min at 4000 rpm and washed with phosphate buffer solution (PBS) for three times. To eliminate somatic cell contamination, sperm pellet was treated with 0.5 % Triton X-100 (Coolaber, Beijing, China) [ 109 ]. Then, Total RNA from boar sperm was extracted with Trizol LS Reagent (Invitrogen Corporation, Carlsbad, CA, USA) according to the manufacturer’s instructions.…”

“…Western blot of METTL3, METTL14, FTO, ALKBH5 and YTHDF2 was performed according to previous report [ 109 ] with some modifications. Briefly, after seminal plasma was removed, sperm pellets were resuspended in a RIPA buffer (containing 1 % phenylmethylsulfonyl fluoride), placed on ice for 30 min and then centrifuged at 12,000 rpm, 4 °C, for 5 min.…”