ABSTRACT
Objective To explore the possible mechanism for KiSSI gene in control gonadotropin - releasing hormone(GnRH)secretion participating in sexual development onset and normal reproduction regulation by investigating the changes in expression of KiSS1,GnRH in hypothalamus and luteinizing hormone(LH),follicle stimulating hormone (FSH),and estradiol(E2 )in serum by using RNA interference mediated by lentivirus - based vectors,after interfering expression of KiSSI. Methods Ninety female Sprague - Dawley rats of 21 days were randomly divided into 3 groups:interference virus group receiving intracerebroventricular injection of KiSSI - microRNA interference lentivirus;lentivi-rus - control group given intracerebroventricular injection of lentivirus without interference effect;9 g/ L saline control group given intracerebroventricular injection of 9 g/ L saline. Ten rats in each group and the animals were sacrificed at 30 - day - old,35 - day - old,45 - day - old,respectively. Then the expressions of KiSSI and GnRH mRNA were detec-ted in the rat hypothalamus with real - time PCR,the LH,FSH,and E2 in serum was examined with chemiluminescence method. Results The levels of KiSSI mRNA in interference virus group were significantly reduced after being infected with recombinant lentivirus compared with those of 9 g/ L saline control group( at 30 d:0. 106 ± 0. 018;at 35 d:0. 218 ± 0. 025;at 45 d:0. 215 ± 0. 033,all P = 0. 000). The level of GnRH mRNA in interference virus group was sig-nificantly reduced after being infected with recombinant lentivirus compared with that of 9 g/ L saline control group(at 30 d:0. 230 ± 0. 040;at 35 d:0. 407 ± 0. 030,all P = 0. 000). The level of LH in interference virus group was lower than the other 2 groups at 35 d[(0. 101 ± 0. 004)IU/ L,P = 0. 467]. The level of FSH in the interference virus group was lower than that of the other 2 groups at 35 d[(0. 235 ± 0. 014)IU/ L,P = 0. 015]. The level of E2 in the interfe-rence virus group was lower than that of the other 2 groups at 35 d and 45 d[at 35 d:(171. 750 ± 11. 050)nmol/ L, P = 0. 000;at 45 d:(192. 310 ± 13. 100)nmol/ L,P = 0. 010]. Conclusions Lentivirus with KiSSI - microRNA can affect the expression of GnRH mRNA and the levels of sex hormone. Lateral cerebral ventricle microinjection of KiSSI -microRNA lentivirus can delay sexual development of Sprague - Dawley female rats.