Ultralow freezer for molecular and cellular biology research

睾丸间质细胞是雄性动物体内主要的睾酮生成细胞。这些细胞对于男性外生殖器、性附属腺、增加肌肉质量以及产生成熟精子的正常发育是不可或缺的。睾丸间质细胞的功能是由垂体促黄体激素（LH）严格控制。LH与位于Leydig细胞表面的受体结合，从而触发几种细胞内信号传导途径（主要涉及cAMP）的激活，导致基因表达和类固醇生成增加。cAMP激活的各种途径仍有待充分阐明。类似地，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，并确定其作用机制。我最初提出，核受体γ 77在LH诱导的Leydig细胞类固醇生成中发挥了重要作用。与我的假设相一致，我们已经表明，CYP 177调节不同的类固醇基因的表达。此外，我们还发现，CAM 77的表达及其活性涉及一种新的cAMP激活的激酶，以前没有在Leydig细胞中描述过：CaMKI。我的研究计划涉及补充国家的最先进的分子和细胞生物学方法，以阐明LH诱导的性腺类固醇激素生成中所发挥的作用，由EST 77。这些方法也被用于破译cAMP激活CaMKI的机制，这似乎涉及细胞内Ca 2+浓度。除了E177，我们也正在研究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大量珍贵的生物材料的生产（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 ℃）下保存。因此，所要求的-86C超低温冷冻机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.