| 摘要: | 背景：外傷早期死亡主要原因包括頭部外傷與出血性休克，晚期則為器官衰竭。研究顯示，外傷好發於年輕男性。許多研究指出性別差異源自於性賀爾蒙效用。肝臟是一個代謝功能複雜且重要的器官，各類休克常導致肝臟衰竭，同時合併極高的死亡率。DNA微陣列提供一個樞紐性工具，讓生物學界能夠了解複雜疾病之基因體變化，而外傷導致生物體急速與巨大衝擊正可提供一個獨特機會得以研究功能性基因體與蛋白質體的變化。
目的：藉由DNA微陣列技術，全面瞭解外傷出血性休克導致基因體表現之變化在性別上的差異，並觀察基因體變化與細胞層級變化及臨床指標，如：細胞激素與雌激素，以期找出其間之關連性。
方法：本實驗之對象為大白鼠，共分三組，每組12隻，雌雄各半。第一組：控制組，第二組：出血性休克組，第三組：急救組。出血性休克採用固定血壓方式，並維持平均動脈壓為45-55毫米汞柱達一小時。實驗結束後四小時給予安樂死，同時將大白鼠肝臟組織取下並且由心臟抽血。以肝組織作為微陣列之分析。血中TNF-α、IL-1β、IL-6、IL-10及17β-estradiol也予以檢測。
結果：出血性休克組雄性4小時雄鼠死亡率為66.7%，雌性則為50%。在死亡個案當中，雄鼠平均存活時間亦較短 (81.3分鐘 vs.123分鐘，p<0.05)。在雌激素方面，雌性明顯高於雄性 (p <0.001)。無論雌雄，出血性休克組血清中四種細胞激素均有最高的表現。在DNA微陣列技術的實驗方面，大白鼠基因晶片(GeneChip®)可檢測31042個基因，研究發現結果發現出血性休克後4.1 %的基因有明顯改變；而以輸液急救後則有3.7%有明顯改變。
討論：出血性休克組雄鼠死亡率較雌鼠高，在死亡個案當中，雄鼠平均存活時間亦較短。這樣的結果顯示雌鼠對外傷出血性休克有較高的忍受性。除了TNF-α以外，三組肝組織基因的表現大致上與血清相對應細胞激素濃度變化一致，其主因可能為TNF-α最早出現，且半衰其很短之故。外傷出血性休克在急性期改變的基因表現大都與細胞內能量製造與代謝機轉有關，部分則與基因訊號傳遞或與細胞基質與結構蛋白質製造相關。
結論：雌性在外傷出血性休克之後的系統性炎症反應的調節中扮演重要角色，由本研究發現它可降低此類損傷早期的死亡率。
Background：The majority of trauma patients in the acute and early categories died as a result of neurologic dysfunction, and hemorrhage. As all are known, the mortality rate of male following trauma is higher compared to that of females. A number of studies indicated that this sex difference was primarily the effect of sex hormones. The liver is a complex metabolically active organ, particularly susceptible to shock, and liver failure carries a high mortality rate. DNA microaray technology provide a pivotal tool in understanding the functional genomics of complex diseases.
Purpose：Under the application of DNA microarray technology, we can have a global understanding of the pattern and difference of immune restoration and gene expression following traumatic hemorrhagic shock in the male and female rats. We also want to correlate these observed gene expressions with cellular change and clinical parameters such as hormone levels and serum cytokine concentrations.
Methods：In our study, mature Sprague-Dawley rats with half for each sex, were divided into three groups, each group having 12 rats: group I: control group (sham operation); group II: hemorrhagic group; group III: resuscitative group . Hemorrhagic shock was induced by withdrawing blood via left femoral artery within 10 minutes and maintain MABP between 45-55 mmHg for one hour . The animals were sacrificed by euthanasia at 4 hrs after the finish of experiment to obtain the liver and whole blood. The liver samples were harvested for microarray analysis. The cytokines including TNF-α, IL-1β, IL-6, IL-10, as well as 17β-estradiol will be measured through the blood samples.
Results: In shock group, the 4-hour mortality rate was 66.7% male subgroup and 50% in female subgroup. Amongthe mortality rats, male rats had shorter mean survival time than females did (81.3 min. vs. 123 min.). In regard to 17-β estradiol, plasma levels in females were significantly higher than those in males (p<0.001). Regardless of sexes, hemorrhagic group had the highest and control group had the lowest plasma levels of TNF-α, IL-1β, IL-6 and IL-10. In the microarray study, the GeneChip® revealed 4.1% (1283/31042) of assessed genes were altered. As compared with hemorrhagic group, the GeneChip® revealed 4.1% (1149/31042) of assessed genes were altered.
Discussion: In shock group, the mortality rate was significant higher in male subgroup. Among the mortality rats, male rats had shorter mean survival time than females did. The current data of mortality and plasma levels of cytokines in shock group suggesting that females have more protective from traumatic hemorrhagic shock than males do. Except for the TNF-α, the gene expression in the liver were approximately in accordance with the corresponding cytokine levels in the blood. Most of the significant genes are energy producing and metabolically related genes, and some are signal transduction and matrix & structural proteins synthesis related.
Conculsion: Female play an important role on modulation for systemic inflammatory response following traumatic hemorrhagic shock and resuscitation, therefore, reduce the early mortality of the injuried rats. |
