Heel K, Blennerhassett L, Kong S E, McCauley R, Hall J
University Department of Surgery, Royal Perth Hospital, Western Australia, Australia.
Br J Surg. 1998 Aug;85(8):1086-9. doi: 10.1046/j.1365-2168.1998.00826.x.
CD44 is an adhesion molecule expressed by neutrophils and lymphocytes which is involved in cell-cell and cell-matrix binding. In this study, the effect of ischaemia-reperfusion injury on CD44 messenger RNA (mRNA) and cell surface immunohistochemical expression of CD44 in the rat small intestine was evaluated.
Wistar rats (n=16) were randomized to either serve as controls (sham surgery) or to be subjected to a standardized ischaemia-reperfusion injury (suprarenal aorta occluded for 1 h followed by 1 h of reperfusion). Standardized segments of jejunum were harvested after ischaemia-reperfusion injury (ischaemic and reperfused samples) to measure the mucosal protein and DNA content, mRNA expression of CD44 and the immunohistochemical expression of CD44.
Reperfusion significantly damaged the jejunal mucosa, e.g. mucosal protein content was lower after reperfusion compared with that in the control group (z=-2.31, P=0.02) and the ischaemic samples (z=-2.52, P=001). The expression of cell surface CD44 protein was also significantly decreased after ischaemic injury (z=-1.99, P=0.04); this coincided with a decrease in the amount of cytoplasmic CD44 mRNA within isolated enterocytes (z=-2.31, P=0.02).
Ischaemia-reperfusion injury decreases the expression of CD44 within the jejunal mucosa. This may contribute to the failure of the gut barrier after such injury.
CD44是一种由中性粒细胞和淋巴细胞表达的黏附分子，参与细胞间和细胞与基质的结合。在本研究中，评估了缺血再灌注损伤对大鼠小肠中CD44信使核糖核酸（mRNA）和CD44细胞表面免疫组化表达的影响。
将16只Wistar大鼠随机分为对照组（假手术）或接受标准化缺血再灌注损伤组（肾主动脉阻断1小时，随后再灌注1小时）。缺血再灌注损伤后（缺血和再灌注样本）采集标准化的空肠段，以测量黏膜蛋白和DNA含量、CD44的mRNA表达以及CD44的免疫组化表达。
再灌注显著损伤空肠黏膜，例如与对照组相比，再灌注后黏膜蛋白含量较低（z = -2.31，P = 0.02），与缺血样本相比也较低（z = -2.52，P = 0.01）。缺血损伤后细胞表面CD44蛋白的表达也显著降低（z = -1.99，P = 0.04）；这与分离的肠细胞内细胞质CD44 mRNA量的减少一致（z = -2.31，P = 0.02）。
缺血再灌注损伤降低了空肠黏膜中CD44的表达。这可能导致此类损伤后肠道屏障功能障碍。
