Ultralow freezer for molecular and cellular biology research

睾丸间质细胞是男性体内产生睾酮的主要细胞。这些细胞对于男性外生殖器、性附腺的正常发育、肌肉质量的增加以及成熟精子的产生都是不可或缺的。间质细胞的功能受到脑下垂体促黄体激素(LH)的严格控制。黄体生成素与间质细胞表面的黄体生成素受体结合，从而激活细胞内的几条信号通路(主要涉及cAMP)，导致基因表达增加和类固醇合成。CAMP激活的各种途径仍未完全阐明。同样，各种信号通路下游的转录因子及其作用机制仍然知之甚少。因此，我的研究计划的目标是确定新的cAMP激活途径和下游分子效应器，并确定它们的作用机制。我最初提出，核受体NUR77在促黄体生成素诱导的间质细胞类固醇合成中起重要作用。与我的假设一致，我们已经证明NUR77调节不同类固醇生成基因的表达。此外，我们发现NUR77的表达以及它的活性涉及一种以前没有在间质细胞中描述的新的cAMP激活的激酶：CaMKI。我的研究计划包括补充最先进的分子和细胞生物学方法，以阐明NUR77在促黄体生成素诱导的性腺类固醇生成中所起的作用。这些方法也被用来破译cAMP激活CaMKI的机制，这似乎与细胞内钙离子浓度有关。除了NUR77，我们还在表征我们最近确定的其他转录因子的作用。我们的各种研究方案导致生产大量珍贵的生物材料(细胞提取物、蛋白质、抗体、DNA、RNA、类固醇激素测量介质等)。这些样品必须在低温(-80摄氏度)下保存。因此，所要求的-86C超低冰柜对于保持我们的生产力和实现我们的目标至关重要。

Testicular Leydig cells are the main testosterone-producing cells in the male. These cells are indispensable for the proper development of external male genitalia, sex accessory glands, increased muscle mass, as well as production of mature sperm. Leydig cell function is tightly controlled by the pituitary luteinizing hormone (LH). LH binds to its receptor located on the surface of Leydig cells thus triggering activation of the several intracellular signaling pathways (the main one involving cAMP) leading to increased gene expression and steroidogenesis. The various pathways activated by cAMP remain to be fully elucidated. Similarly, the transcription factors downstream of the various signaling pathways and their mechanisms of action remain poorly understood. Therefore, the goal of my research programme is to identify novel cAMP-activated pathways and the downstream molecular effectors and to determine their mechanism of action. I had originally proposed that the nuclear receptor NUR77 played an important role in LH-induced Leydig cell steroidogenesis. Consistent with my hypothesis, we have shown that NUR77 regulates expression of different steroidogenic genes. In addition, we found that NUR77 expression as well as its activity involve a novel cAMP-activated kinase not previously described in Leydig cells: CaMKI. My research programme involves complementary state-of-the-art molecular and cellular biology approaches to elucidate the roles played by NUR77 in LH-induced gonadal steroidogenesis. These approaches are also used to decipher the mechanisms of CaMKI activation by cAMP, which appears to involve intracellular Ca2+ concentrations. In addition to NUR77, we are also characterizing the roles of other transcription factors we have recently identified. Our various research protocols lead to the production of large quantities of precious biological materials (cell extracts, proteins, antibodies, DNA, RNA, media for steroid hormone measurements, etc). These samples must be preserved at low temperatures (-80C). Therefore, the requested -86C ultralow freezer is essential to maintain our productivity and achieve our goals.