Kisspeptin expression in mouse Leydig cells correlates with age.
BACKGROUND
Kisspeptin, encoded by the Kiss1 gene, has many forms including kisspeptin54, kisspeptin14, kisspeptin13, and kisspeptin10, and all these peptides have the same affinity to their receptor KISS1R encoded by the Kiss1r gene. The KISS1-KISS1R system was discovered in neurons, and many reports stress on their function in the brain. However, recent studies have shown that Kiss1 and Kiss1r are expressed in the testes. The goal of this study was to demonstrate the roles of Kiss1 and Kiss1r in testicular function, especially their steroidogenic activity.


METHODS
Kisspeptin10 and the kisspeptin10 antagonist peptide234 were used to determine their effect on testosterone production. Moreover, expression of steroidogenic genes in mouse testes and their gonadosomatic index (weight of the testes divided by the total body weight) and also serum testosterone level were studied between the ages of 2 weeks and 15 weeks.


RESULTS
Kisspeptin10 and peptide234 did not affect testosterone production in primary Leydig cells from adult mice. Kiss1 and Esr1 expression also increased during puberty. The peak gonadosomatic index occurred at 4 weeks of age, and serum testosterone levels plateaued after the age of 4 weeks.


CONCLUSIONS
Our results suggest that kisspeptin10 does not affect steroidogenesis in adult Leydig cells, but its pattern of expression follows the stages of testicular development. Future studies should determine if kisspeptin regulates testicular development during puberty.
Department of Animal Science and Technology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan, ROC.
Jyun-Yuan
JY
Wang
Department of Animal Science and Technology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan, ROC.
Meng-Chieh
MC
Hsu
Department of Animal Science and Technology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan, ROC.
Tai-Hsiang
TH
Tseng
Department of Animal Science and Technology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan, ROC.
Leang-Shin
LS
Wu
Department of Animal Science and Technology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan, ROC.
Kuo-Tai
KT
Yang
Department of Animal Science and Technology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan, ROC. Electronic address: chiuchihhsien@ntu.edu.tw.
Chih-Hsien
CH
Chiu
D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics; D000367:Age Factors; D000818:Animals; D002478:Cells, Cultured; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics; D047628:Estrogen Receptor alpha / Q000235:genetics; D059648:Kisspeptins / Q000502:physiology*; D007985:Leydig Cells / Q000502:physiology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D043562:Receptors, G-Protein-Coupled / Q000502:physiology; D000074502:Receptors, Kisspeptin-1; D013739:Testosterone / Q000097:blood
D047628:Estrogen Receptor alpha; C491407:Kiss1 protein, mouse; C492248:Kiss1r protein, mouse; D059648:Kisspeptins; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1; D013739:Testosterone; D015096:3-Hydroxysteroid Dehydrogenases; D002786:Cholesterol Side-Chain Cleavage Enzyme
Leydig cells; kisspeptin; puberty; steroidogenesis