Abstract:
MafB is a transcription factor that regulates macrophage differentiation. Macrophages are a traditional feature of the hamster Harderian gland (HG); however, studies pertaining to MafB expression in the HG are scant. Here, the full-length cDNA of the MafB gene in hamsters was cloned and sequenced. Molecular characterization revealed that MafB encodes a protein containing 323 amino acids with a DNA-binding domain, a transactivation domain, and a leucine zipper domain. qPCR assays indicated that MafB was expressed in different tissues of both sexes. The highest relative expression levels in endocrine tissues were identified in the pancreas. Gonadectomy in male hamsters was associated with significantly higher mRNA levels in the HG; replacement with dihydrotestosterone restored mRNA expression. The HG in male hamsters contained twofold more MafB mRNA than the HG of female hamsters. Adrenals revealed similar mRNA relative expression levels during the estrous cycle. The estrous phase was associated with higher mRNA levels in the ovary. A significantly up-regulated expression and sexual dimorphism of MafB was found in the pancreas. Therefore, MafB in the HG may play an active role in the macrophage differentiation required for phagocytosis activity and intraocular repair. Additionally, sex steroids appear to strongly influence the MafB expression in the HG and pancreas. These studies highlight the probable biological importance of MafB in immunological defense and pancreatic β cell regulation.
摘要:
MafB是调节巨噬细胞分化的转录因子。巨噬细胞是仓鼠Harderian腺(HG)的传统特征;但是,关于MafB在HG中表达的研究很少。这里,对仓鼠中MafB基因的全长cDNA进行克隆和测序。分子特征显示MafB编码含有323个氨基酸的蛋白质,具有DNA结合域,一个反式激活域,和一个亮氨酸拉链域。qPCR测定表明MafB在两种性别的不同组织中表达。在胰腺中鉴定出内分泌组织中的最高相对表达水平。雄性仓鼠的性腺切除术与HG中mRNA水平显着升高有关;用二氢睾酮替代可恢复mRNA表达。雄性仓鼠的HG比雌性仓鼠的HG包含两倍多的MafBmRNA。肾上腺在发情周期中显示出相似的mRNA相对表达水平。发情期与卵巢中较高的mRNA水平有关。在胰腺中发现了MafB的显着上调表达和性二态。因此,HG中的MafB可能在吞噬活性和眼内修复所需的巨噬细胞分化中起积极作用。此外,性类固醇似乎强烈影响HG和胰腺中MafB的表达。这些研究强调了MafB在免疫防御和胰腺β细胞调节中可能的生物学重要性。