Maintenance of Organ Function Following Injury

描述(申请人提供)：我们的研究表明，在创伤-出血和复苏(T-H)后，男性的各种器官的功能明显受到抑制，但发情前期的女性(雌激素水平较高)则不明显。此外，T-H后男性心肌细胞雌激素受体(ER)的表达显著减少，而雄激素受体(AR)的表达不明显。男性在T-H后服用E2可使心肌细胞ER和心功能正常化。此外，在T-H后，男性服用AR拮抗剂氟他胺可使心脏E2水平、ER水平、线粒体ATP水平和心功能正常化。我们推测，发情前期女性体内普遍存在的荷尔蒙环境有助于维持器官细胞中ER的表达，从而保护器官血流，防止局部缺氧，维持线粒体ATP的生成和器官功能。拟进行的研究将确定：a)动情周期不同阶段雄性和雌性不同器官细胞和线粒体ER表达降低的程度，以及ER降低是否与线粒体ATP水平/器官功能改变有关；b)E2是否使所有细胞/器官的ER表达正常化，并在T-H后恢复器官功能；c)基于细胞的治疗，即给予转基因骨髓间充质干细胞(MSC)过表达ER是否会在T-H后上调细胞内的ER，并改善器官功能，即使在没有外源E2的情况下也是如此。由于男性在T-H后发生区域性缺氧，预计会产生内质网(EPR)应激。我们预计EPR应激和ER水平之间存在负相关关系，并且在T-H后应用E2可以缓解EPR应激并使ER水平正常化。研究还将确定男性和女性在T-H后各种细胞中促凋亡和抗凋亡因子、线粒体ATP和自由基产生的变化，以及E_2治疗是否使这些参数正常化并在T-H后恢复细胞/器官功能。由于T-H后的MSC治疗有望加速器官的恢复，我们将确定E2和MSC联合治疗在改善细胞/器官功能和降低后续脓毒症的死亡率方面是否更有效。利用E2、基于细胞的治疗和其他最先进的细胞/分子技术整合细胞和器官的功能，应该确定ER调节T-H后器官效应器反应的新机制(S)。这些发现应有助于开发和应用针对性别的治疗，以预防心血管和其他器官功能障碍，从而减少男性和女性创伤受害者随后发生的脓毒症的发病率和死亡率。公共卫生相关性：我们将研究创伤后使用女性性激素可以改善细胞和器官功能并降低感染性并发症致死率的机制。我们将使用最先进的分子技术和基于细胞的治疗来描述损伤发病机制。这笔资金将有助于开发针对性别的治疗方法。这种治疗应防止创伤后的器官功能障碍，并降低男性和女性创伤受害者随后发生的脓毒症的发病率和死亡率。

DESCRIPTION (provided by applicant): Our studies demonstrate that the functions of various organs are markedly depressed in males, but not in proestrus females (with high estrogen [E2] levels) after trauma-hemorrhage and resuscitation (T-H). Moreover, estrogen receptor (ER) but not androgen receptor (AR) expression in cardiomyocytes from males was significantly decreased after T-H. Administration of E2 after T-H in males normalized cardiomyocyte ER and cardiac functions. Furthermore, administration of AR antagonist flutamide in males after T-H normalized cardiac E2 levels, ER levels, mitochondrial ATP levels, and cardiac functions. We hypothesize that the prevailing hormonal milieu in proestrus females helps maintain ER expression in cells of organs and thus preserves organ blood flow, prevents regional hypoxia, maintains mitochondrial ATP production and organ functions. The proposed studies will determine: a) the extent to which ER expression is decreased in cells and mitochondria of various organs in males and females in different stages of the estrus cycle and if the decreased ER is associated with altered mitochondrial ATP levels/organ functions; b) if E2 normalizes ER expression in all cells/organs, and restores organ functions after T-H; c) if cell-based therapy, i.e., administration of genetically modified bone marrow mesenchymal stem cells (MSC) to over-express ER will upregulate ERs in cells and improve organ function after T-H even in the absence of exogenous E2. Since regional hypoxia occurs after T-H in males, it is expected to produce endoplasmic reticulum (EPR) stress. We expect an inverse relationship between EPR stress and ER levels and E2 administration should alleviate EPR stress and normalize ER levels after T-H. Studies will also determine alterations in pro- and anti-apoptotic factors in various cells, mitochondrial ATP and free radical production following T-H in males and females, and whether E2 treatment normalizes these parameters and restores cell/organ functions after T-H. Since MSC therapy after T-H is expected to accelerate recovery of organs, we will determine if the combination of E2 and MSC therapy is more effective in improving cell/organ function and reducing mortality from subsequent sepsis. The integration of cell and organ functions using E2, cell-based therapy and other state-of-the-art cellular/molecular techniques, should identify novel mechanism(s) by which ERs regulate organ effector responses after T-H. The findings should facilitate the development and application of gender-specific therapy for preventing cardiovascular and other organ dysfunction and thus reducing morbidity and mortality from subsequent sepsis in male and female trauma victims. PUBLIC HEALTH RELEVANCE: We will examine the mechanisms by which the use of female sex hormones after trauma will improve cell and organ functions and decrease the lethality from infectious complications. We will use state-of-the-art molecular techniques and cell-based therapy to delineate the mechanisms involved in injury pathogenesis. The funding will help to develop gender-specific therapy. Such therapy should prevent organ dysfunction after injury and reduce morbidity and mortality from subsequent sepsis in male and female trauma victims.