We have analyzed the ontogeny and putative mechanisms of transregulation of LH receptor (LHR) and transcription factor GATA-4, coexpressed during the adrenocortical tumorigenesis of prepubertally gonadectomized transgenic (TG) mice expressing the inhibin alpha-subunit promoter/simian virus 40 T-antigen (inhalpha/Tag) transgene. The onset of adrenal LHR mRNA and protein expression coincided with that of GATA-4 at the age of 4 months and preceded the appearance of discernible adrenal tumors at about 6 months. In situ hybridization and double-immunohistochemistry demonstrated colocalization of the LHR and GATA-4 messages and proteins in the adrenal cortex. A GATA-4 expression plasmid cotransfected with a murine LHR promoter-driven luciferase reporter plasmid, containing a consensus GATA-binding site, induced a dose-dependent significant transactivation of the LHR promoter in nonsteroidogenic human embryonic kidney 293, steroidogenic murine mLTC-1 Leydig cells and in murine adrenal Y-1 cells. The Calpha1 cells derived from an Inhalpha/Tag adrenal tumor did not show this response, apparently due to their high endogenous GATA-4 expression. However, an additional link between GATA-4 and LHR in Calpha1 cells was provided upon the LH/human chorionic gonadotropin stimulation of LHR promoter activity; mutations or deletion of the consensus GATA-4 binding site of the LHR promoter abolished this transactivation. EMSAs further proved GATA-4 binding to the putative consensus GATA recognition site. Our results demonstrate direct interrelationship between LHR and GATA-4 expression during adrenocortical tumorigenesis of the inhalpha/Tag mice. There is apparently a positive and reciprocal feed-forward amplification link between LHR and GATA-4 expression. This mechanism gradually and in synergy with Tag expression leads to formation of the LH-dependent adrenocortical tumors.
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http://dx.doi.org/10.1210/me.2002-0282 | DOI Listing |
Acta Biochim Biophys Sin (Shanghai)
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Institute of Clinical Anatomy & Reproductive Medicine, Department of Histology and Embryology, Hengyang Medical School, University of South China, Hengyang 421001, China.
Radiotherapy, a common cancer treatment, leads to infertility in male cancer survivors, particularly young and middle-aged patients. Nicotinamide mononucleotide (NMN), a precursor of nicotinamide adenine dinucleotide (NAD ), plays crucial roles in energy metabolism, DNA repair, and gene expression. The purpose of this study is to investigate the protective effects and underlying mechanisms of NMN against ionizing radiation (IR)-induced testicular injury and spermatogenic dysfunction in an adult male mouse model.
View Article and Find Full Text PDFiScience
October 2024
Department of Cardiovascular Surgery, the First People's Hospital of Yunnan Province, No.157 Jinbi Road, Kunming, Yunnan 650032, China.
F1000Res
July 2024
Department of Cardiology and Vascular Medicine, Faculty of Medicine Universitas Airlangga, Dr. Soetomo Academic General Hospital, Surabaya, East Java, 60286, Indonesia.
Background: There is an essential need for cardiomyocyte regeneration among patients with heart failure. Transplantation of dedifferentiated fat (DFAT) cells may lead to an improvement of cardiomyocyte regeneration among heart failure patients. We believe that DFAT cells are promising candidate cell sources for cardiac regeneration.
View Article and Find Full Text PDFClin Proteomics
May 2024
Lawson Health Research Institute, London, ON, N6C 2R5, Canada.
Beijing Da Xue Xue Bao Yi Xue Ban
April 2024
Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing 100191, China.
Objective: To evaluate the developmental toxicity of Cry1Ab protein by studying its effects on cell proliferation and differentiation ability using a developmental toxicity assessment model based on embryonic stem-cell.
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