Treatment with nitrite prevents reactive oxygen species generation in the corpora cavernosa and restores intracavernosal pressure in hypertensive rats

Influence of l-NAME -induced hypertension on spermatogenesis and sperm tsRNA profile in mice

Sperm is the key media between the father's aberrant exposure and the offspring's phenotype. Whether paternal hypertension affects offspring through sperm epigenetics remains to be explored. To investigate the underlying mechanisms, we constructed a hypertensive mice model induced by drinking l-NAME and found that spermatocytes and spermatids in the testis were increased significantly after l-NAME treatment. The sequencing of sperm showed that tsRNA profiles changed with 315 tsRNAs (195 up-regulated and 120 down-regulated) altered. Meanwhile, KEGG pathway analysis showed that the target genes of these altered tsRNAs were involved in influencing some important signaling pathways, such as the cAMP signaling path, the mTOR signaling path, the Hippo signaling path, and the Ras signaling path. Bioinformatics of tsRNA-miRNA-mRNA pathway interactions revealed several ceRNA mechanisms, such as tsRNA-00051, the ceRNA of miR-128-1-5p, co-targeting Agap1. This study provides evidence for enriching and further understanding the pathophysiology and paternal epigenetic mechanisms of testicular reproduction, as well as contributing to a rethinking of the transgenerational reprogramming mechanisms of paternal exposure in hypertension.

Icariin modulates eNOS activity via effect on post-translational protein-protein interactions to improve erectile function of spontaneously hypertensive rats

BACKGROUND

Type 5 phosphodiesterase inhibitor (PDE5I) has become the first-line treatment for erectile dysfunction (ED). However, its effective rate for hypertension ED is only 60%-70%. How to improve the efficacy of ED treatment is the focus of current research.

OBJECTIVE

To explore whether icariin can improve the erectile function of spontaneously hypertensive rats (SHR) by affecting post-translational protein-protein interactions to regulate endothelial nitric oxide synthetase (eNOS) activity.

METHOD

Twelve-week-old healthy male SHR rats and Wistar-Kyoto rats (WKY) were randomly divided into four groups: SHR control group, SHR + icariin (10 mg/kg·d gavage) treatment group, WKY control group, and WKY + icariin (10 mg/kg·d gavage) treatment group (n = 5). After 4 weeks, the maximum penile intracavernous pressure/mean arterial pressure (ICPmax/MAP), the expression of heat-shock protein 90 (Hsp90), caveolin-1, calmodulin, p-eNOS, and eNOS in penile cavernous tissue and the content of nitric oxide (NO) and cGMP were measured. The interaction between eNOS and Hsp90, caveolin-1, and calmodulin were detected by immunoprecipitation.

RESULT

The ICPmax/MAP in the SHR + icariin treatment group (0.08 ± 0.01, 0.23 ± 0.07, 0.40 ± 0.05) was significantly higher than the SHR group (0.03 ± 0.01, 0.13 ± 0.03, 0.21 ± 0.02) under 3V and 5V electrical stimulations (P < .05). Compared with the SHR group, the expression of HSP90, calmodulin, P-eNOS, eNOS, and P-eNOS/eNOS in the penile cavernous tissue of rats in the WKY group and the SHR + icariin treatment group were significantly increased (P < .05), and the expression of caveolin-1 was significantly decreased (P < .05). The NO content (2.16 ± 0.22 μmol/g) and cGMP concentration (3.69 ± 0.12 pmol/mg) in the SHR + icariin treatment group were significantly higher than those in the SHR group (1.01 ± 0.14 μmol/g, 2.31 ± 0.22 pmol/mg) (P < .05). Compared with the SHR group, the interaction between eNOS and HSP90 in the cavernosa of the rats in the SHR + icariin treatment group was significantly increased (P < .05), the interaction between eNOS and caveolin-1 was significantly decreased (P < .01), and the interaction between eNOS and calmodulin did not significantly change.

DISCUSSION AND CONCLUSION

Up-regulating the expression of HSP90 and calmodulin and inhibiting caveolin-1 in SHR corpus cavernosum, promoting the interaction between eNOS and HSP90, inhibiting the interaction between eNOS and caveolin-1, increasing p-eNOS/eNOS, may be the mechanism of icariin that improves SHR erectile function.