Ultralow freezer for molecular and cellular biology research

睾丸间质细胞是男性体内主要的产生睾丸激素的细胞。这些细胞对于男性外生殖器的正常发育、性腺、肌肉质量的增加以及成熟精子的产生是必不可少的。间质细胞的功能受垂体黄体生成素（LH）的严格控制。LH与其位于间质细胞表面的受体结合，从而触发几个细胞内信号通路的激活（主要涉及cAMP），导致基因表达增加和类固醇生成。cAMP激活的各种途径仍有待充分阐明。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物，并确定其作用机制。我最初提出核受体NUR77在lh诱导的间质细胞甾体生成中起重要作用。与我的假设一致，我们已经证明NUR77调节不同类固醇基因的表达。此外，我们发现NUR77的表达及其活性涉及一种以前未在间质细胞中描述的新的camp活化激酶：CaMKI。我的研究项目包括互补的最先进的分子和细胞生物学方法，以阐明NUR77在lh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CaMKI被cAMP激活的机制，这似乎涉及细胞内Ca2+浓度。除了NUR77，我们还描述了我们最近发现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，用于类固醇激素测量的介质等）。这些样品必须在低温（-80℃）下保存。因此，我们所要求的-86摄氏度的超低温冰箱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.