GENDER DIFFERENCES IN CELLULAR RESPONSE TO CHALLENGES

自身免疫性疾病和其他疾病经常表现出性别差异，这通常归因于激素的差异。这一解释不能解释性别之间的频率差异，而不是严重程度差异；它也不能解释为什么激素预防常常不能缓解问题。我们提出，在其他方面相同的男性和女性细胞之间固有的生物学差异可能是差异的来源。对这种可能性的研究很少。我们在初步研究中发现，男性和女性细胞在对细胞死亡诱导刺激的反应中存在显著差异，这与现有的少数出版物一致。我们将从胚胎小鼠的几个组织（肝脏、大脑、胸腺、心脏）中收集细胞，对胚胎进行性别鉴定，并记录它们在子宫中的位置和相邻细胞的性别，以此来分析这种可能性。我们将在原代培养中培养这些细胞，并用一系列诱导细胞死亡的刺激刺激它们，包括常用的实验室挑战，如H2O2和乙醇，生理挑战，如tnf - α， Fas和Fas配体，糖皮质激素，以及医学上相关的化疗药物。我们将评估男性和女性细胞对这些挑战的剂量和时间依赖性敏感性。这项评估将包括直接观察细胞的活力，以及分析细胞死亡的哪些方面有不同的反应：神经酰胺第二信使信号的激活、半胱天蛋白酶和溶酶体的活性，以及染色质和DNA的降解。从最早的胚胎开始，我们将把研究扩展到后来的胚胎、新生儿、青少年和发育期动物，以确定体内的差异是否可以用最初的遗传差异来解释，或者它们是否只在暴露于性激素之后才出现。在这些实验中，我们还将能够确定在没有激素的情况下，激素衍生的差异持续存在的程度。这些实验既是对疾病性别差异机制的直接探究，也是本研究人员进入自身免疫性疾病性别差异领域的切入点。

Autoimmune and other diseases frequently manifest a sexual disparity that is often attributed to hormonal differences. This explanation does not account for the difference in frequency rather than severity between the sexes; nor does it explain the frequent failure of hormonal countervention to alleviate a problem. We propose that inherent biological differences between otherwise identical male and female cells can be a source of the disparity. Such a possibility has been studied only minimally. We have found in initial studies, which are consistent with the few publications available, that there is a marked difference between male and female cells in their responses to cell death inducing stimuli. We will analyze this possibility by collecting cells from several tissues (liver, brain, thymus, heart) of embryonic mice, sexing the embryos and noting both their position in the uterus and the sex of their neighbors. We will culture these cells in primary culture and challenge them with a range of cell death inducing stimuli, including commonly used laboratory challenges such as H2O2 and ethanol, physiological challenges such as TNF-alpha, Fas and Fas ligand, and glucocorticoids, and medically relevant chemotherapeutic agents. We will assess the dose- and time-dependent sensitivity of the male and female cells to these several challenges. This assessment will include direct observation of the viability of the cells as well as analysis of which aspects of cell death respond differentially: activation of ceramide 2nd messenger signaling, caspase and lysosome activity, and degradation of chromatin and DNA. Starting with the eatliest embroyos that we can sex, we will extend the studies to include later embryos, newborns, juveniles, and pubertal animals, to determine whether the in vivo differences can be accounted for by initial genetic differences or whether they arise only after exposure to sex hormones. In these experiments we will also be able to determine the extent to which hormone-derived differences persist in the absence of hormones. These experiments represent both a direct inquiry into the mechanism of gender related difference in disease and an entry point for this investigator to the field of gender differences in autoimmune disease.