PURPOSE: This study investigated the role of natriuretic peptide receptor 2 (NPR2) on cell proliferation and testosterone secretion in mouse Leydig cells. MATERIALS AND METHODS: Mouse testis of different postnatal stages was isolated to detect the expression C-type natriuretic peptide (CNP) and its receptor NPR2 by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Leydig cells isolated from mouse testis were cultured and treated with shNPR2 lentiviruses or CNP. And then the cyclic guanosine monophosphate production, testosterone secretion, cell proliferation, cell cycle and cell apoptosis in mouse Leydig cells were analyzed by ELISA, RT-qPCR, Cell Counting Kit-8, and flow cytometry. Moreover, the expression of NPR2, cell cycle, apoptosis proliferation and cell cycle related gene were detected by RT-qPCR and Western blot. RESULTS: Knockdown of NPR2 by RNAi resulted in S phase cell cycle arrest, cell apoptosis, and decreased testosterone secretion in mouse Leydig cells. CONCLUSIONS: Our study provides more evidences to better understand the function of CNP/NPR2 pathway in male reproduction, which may help us to treat male infertility.
Animals ; Apoptosis ; Blotting, Western ; Cell Count ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Proliferation ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Germ Cells ; Guanosine Monophosphate ; Humans ; Infertility, Male ; Lentivirus ; Leydig Cells ; Male ; Mice ; Natriuretic Peptide, C-Type ; Polymerase Chain Reaction ; Receptors, Peptide ; Reproduction ; Reverse Transcription ; RNA Interference ; S Phase ; Testicular Diseases ; Testis ; Testosterone

Objective To investigate the correlation between iodine nutritional status and thyroid diseases in some areas of Ningxia. Methods The physical examination, questionnaire survey, and measurement of urine iodine, thyroid function, thyroid associated antibodies were performed, with thyroid ultrasonography in Jingyuan County, Xingqing District and Guyuan City, Ningxia Yinchuan City, totally including 2827 adults. Results The median urinary iodine of all subjects was 258. 7(76. 6-1506. 4) μg/L. The average level of urinary iodine in rural areas [203.3(64. 6-1154)μg/L] was lower than that in cities[340. 7(114. 8-1726. 1)μg/L, Z=19. 514, P>0. 01]. The average urinary iodine level was lower in people over 65 years old[234. 2(58. 9-2285. 4) μg/L, x2=6.449, P=0. 040]. Subjects in hypothyroidism group [232. 5(69. 2-1682. 3) μg/L] had the lowest average urinary iodine level, while hyperthyroidism group[331. 9(102. 4-1862) μg/L] turned to be the highest group( x2=15. 432, P>0. 01). Compared with the normal group, TPOAb and TGAb increased group had similar median levels of urinary iodine (P>0. 05). If compared with single nodule, multiple nodules group and the normal group's median levels of urinary iodine also had no significant difference(P>0. 05). Conclusion Iodine excess was found in the studied population in these areas of Ningxia.