Long noncoding RNA H19 promotes the apoptosis of corpus cavernsum smooth muscle cells after cavernosal nerve injury via JNK signalling pathway

JNK/ Bcl-2/ Bax pathway participates in corpus cavernosal smooth muscle cells apoptosis during early period after cavernosal nerve (CN) crush injury (CNCI). Nevertheless, the regulation mechanisms of long noncoding RNA H19 in apoptosis during early stage after CN injury are still poorly understood. The rats in sham group were not direct injury to the CNs. The rats in CNCI group were performed to bilateral CN crush injury. The ICP/MAP rate and smooth muscle content were significantly lower than that in the sham group. Primary CCSMCs were prepared from the tissues samples after completing erectile function detection. Phosphorylated-JNK level was increased significantly, and the expression of Bax and Bcl-2 was elevated and declined in CNCI group respectively. Except for Bcl-2, the mRNA levels of H19, JNK and Bax were significantly increased in CNCI group. After H19 siRNA transfection, for the mRNA and protein levels, JNK and Bax were declined, while Bcl-2 was enhanced. LncRNA H19 might be involved in regulation of Bcl-2, Bax via JNK signalling pathway in CCSMCs apoptosis after CN injury.     

8‐isoprostane F2α up‐regulates the expression of type 5 phosphodiesterase in cavernosal vascular smooth muscle cells: inhibition with sildenafil,iloprost, nitric oxide and picotamide

OBJECTIVES

To explore the possible role of of 8‐isoprostane F_2α (8‐IPF_2α) in the aetiology of erectile dysfunction (ED), as the over‐production of superoxide (O₂^‐) derived from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase results in the formation of 8‐IPF_2α in vascular tissue, which has similar properties to thromboxane A₂ (TXA₂). TXA₂ is vasoconstrictor and up‐regulates the expression of NADPH oxidase and phosphodiesterase type 5 (PDE5).

MATERIALS AND METHODS

Cavernosal vascular smooth muscle cells (CVSMCs) were incubated with 8‐IPF_2α or the TXA₂ analogue, U46619, ±sildenafil, iloprost (a stable prostacyclin [PGI₂] analogue) or the nitric oxide (NO) donor NONOate for 16 h. The formation of O₂^‐ was then measured, PDE5 expression assessed using Western blotting and PGI₂ and 8‐IPF_2α formation measured using enzyme‐linked immunoassays.

RESULTS

8‐IPF_2α promoted the formation of O₂^‐, an effect inhibited by apocynin (an NADPH oxidase inhibitor) and up‐regulated the expression of PDE5. Under identical incubation conditions, 8‐IPF_2α induced an increase in the formation of 8‐IPF_2α but reduced the formation of PGI₂. All, these effects were reversed by sildenafil, iloprost, NONOate and picotamide.

CONCLUSIONS

These data show that O₂^‐ derived from NADPH oxidase influences the relative balance of PGI₂ and 8‐IPF_2α in CVSMCs, which in turn alters the degree of PDE5 expression. This is a novel pathogenic mechanism underlying ED and a novel mechanism of action of sildenafil.