Archives

  • 2018-07
  • 2018-10
  • 2018-11
  • 2019-04
  • 2019-05
  • 2019-06
  • 2019-07
  • 2019-08
  • 2019-09
  • 2019-10
  • 2019-11
  • 2019-12
  • 2020-01
  • 2020-02
  • 2020-03
  • 2020-04
  • 2020-05
  • 2020-06
  • 2020-07
  • 2020-08
  • 2020-09
  • 2020-10
  • 2020-11
  • 2020-12
  • 2021-01
  • 2021-02
  • 2021-03
  • 2021-04
  • 2021-05
  • 2021-06
  • 2021-07
  • 2021-08
  • 2021-09
  • 2021-10
  • 2021-11
  • 2021-12
  • 2022-01
  • 2022-02
  • 2022-03
  • 2022-04
  • 2022-05
  • 2022-06
  • 2022-07
  • 2022-08
  • 2022-09
  • 2022-10
  • 2022-11
  • 2022-12
  • 2023-01
  • 2023-02
  • 2023-03
  • 2023-04
  • 2023-05
  • 2023-06
  • 2023-07
  • 2023-08
  • 2023-09
  • 2023-10
  • 2023-11
  • 2023-12
  • 2024-01
  • 2024-02
  • 2024-03
  • br Acknowledgments R Dalmann has obtained

    2022-06-30


    Acknowledgments R. Dalmann has obtained a “bourse Cifre” (grant 304/2011) from the ‘Association Nationale de la Recherche Technique’ and Bristol-Myers-Squibb.
    Introduction Endocannabinoids, their molecular targets (receptors), their synthetic and degrading enzymes and proteins that transport the ligands in and out of the cells constitute the endocannabinoid system (ECS) [1]. Among the endocannabinoids, N-Arachidonoylethanolamide (Anandamide, AEA) was the first to be discovered and is the most studied [2]. A fully functional ECS that synthesize, bind and degrade AEA is reported in human [3,4], boar [5], mouse [6,7], and bovine [8] spermatozoa. Further, it has been reported that AEA protect spermatozoa during cryopreservation [9], play a role in sperm acquisition of fertilizing potential [10,11] and modulate sperm-oviduct binding and subsequent release [8,12]. The action of AEA is mediated through type-1 (CB1) and type-2 (CB2) endocannabinoid receptors; however CB1 is involved in the sperm acquisition of fertilizing ability and oviduct binding [12,13]. Recent evidences indicate the role of ECS on reproductive potential of men [14]. Studies have shown that the ECS is a key player in the multifaceted process of male reproduction [10,15]. Activation of CB1 modulates motility, capacitation, and acrosome reaction in human, bovine and boar spermatozoa [3,5,8]. On the other hand, membrane-bound fatty Calpain Inhibitor II, ALLM mg amide hydrolase (FAAH) controls the cellular uptake of AEA and quickly terminate its effect [16]. The genetic loss of FAAH in the mouse resulted in increased levels of AEA in the reproductive system, leading to an impairment of sperm fertilizing ability [7]. In infertile men, it is reported that alterations in the ECS might impact sperm capacitation and acrosome reaction, and hence fertilization outcomes [10]. Very recently, we have shown that the effect of AEA on sperm-oviduct binding was mediated through CB1 receptor and CB1 antagonist reversed the inhibitory effect of AEA on sperm oviduct binding in buffalo bulls [12]. Accumulating evidences in human being indicate a possible role of ECS in male fertility [3,4,6,10]. Although the effect of exogenous or endogenous cannabinoid signaling on sperm functions has been studied to some extent, little is known about the possible involvement of the ECS in sperm in male fertility in livestock. Since evidence indicates that AEA signaling might regulate sperm functions and fertility [4,5,10,17], we hypothesised that the expression of CB1 and FAAH might differ in spermatozoa from bulls with different field fertility ratings. Thus, the aims of the present study were 1) to study the transcriptional abundance of CB1 and FAAH in dairy bulls with different field fertility ratings and 2) to investigate their relationship with field fertility of the bulls.
    Materials and methods
    Results The proportion of viable spermatozoa was significantly (p < 0.05) lower in low fertile bulls compared to either high or medium fertile bulls. The proportion of capacitated spermatozoa was significantly (p < 0.05) higher in low fertile bulls compared to both high and medium fertile bulls (Fig. 2). There was no significant difference in the proportion of protamine deficient spermatozoa among the three categories of the bulls. The results of q-PCR experiments on gene expression of the endocannabinoid receptor (CB1) and AEA degrading enzyme (FAAH) in spermatozoa from bulls with different levels of fertility are shown in Fig. 3, Fig. 4A. The mRNA levels of CB1 receptor was significantly (p < 0.05) lower in spermatozoa from low and medium fertile bulls than high fertile bulls. The relative expression of CB1 receptor in spermatozoa was 1.86 ± 0.74 in high fertile bulls while it was 0.09 ± 0.04 in low fertile bulls. The fold change in the expression of CB1 gene was 21.07 and 4.23 times in high and medium fertile bulls, respectively compared to low fertile bulls.