Kremlev Sergey G, Roberts Rebecca L, Palmer Charles
The Milton S. Hershey Medical Center, The College of Medicine, Hershey, Pennsylvania 19122, USA.
J Neurosci Res. 2007 Aug 15;85(11):2450-9. doi: 10.1002/jnr.21380.
Hypoxic-ischemic (HI) brain injury in the perinatal period causes significant morbidity. Minocycline (MN) is a tetracycline derivative that has reduced brain injury in various animal models of neurodegeneration, including perinatal ischemia. To determine whether MN can modulate the expression of chemokine receptors and interleukin-10 (IL10) in a model of neonatal brain injury, we produced an HI insult to the right cerebral hemisphere (ipsilateral) of the 7-day-old rat (PD7) by right common carotid artery ligation and 2.25 hr of hypoxia in 8% oxygen. MN (45 mg/kg, i.p.) or vehicle (PBS) was injected twice: 2 days and immediately before the HI insult. At 0, 1, 3, and 24 hr and 14 days after HI, total RNA from the ipsilateral and contralateral (exposed to hypoxia only) hemispheres was extracted, reverse transcribed, and amplified with gene-specific primers using a semiquantitative RT-PCR for macrophage inflammatory protein-1alpha), interferon-inducible protein (IP-10), C-C chemokine receptor 5 (CCR5; MIP-1alpha receptor), C-X-C chemokine receptor 3 (CXCR3; IP-10 receptor), and IL10. We found that, in the ipsilateral hemisphere, a significant (P < 0.05) increase in MIP-1alpha, IP-10, CCR5, and CXCR3 mRNA levels was observed. MN treatment decreased mRNA levels for CCR5 and CXCR3. In contrast, the levels of antiinflammatory cytokine IL10 were markedly decreased as a result of HI insult. Treatment with MN, however, had no effect on IL10. We conclude that MN decreased proinflammatory chemokine receptor expression but had little or no influence on the expression of antiinflammatory cytokine IL10. These effects confirm the antiinflammatory effect of MN in neonatal HI brain injury.
围生期缺氧缺血性（HI）脑损伤会导致严重的发病情况。米诺环素（MN）是一种四环素衍生物，在包括围生期缺血在内的各种神经退行性疾病动物模型中都能减轻脑损伤。为了确定MN是否能在新生儿脑损伤模型中调节趋化因子受体和白细胞介素-10（IL10）的表达，我们通过结扎7日龄大鼠（出生后第7天，PD7）的右侧颈总动脉并在8%氧气浓度下缺氧2.25小时，对其右侧大脑半球（同侧）造成HI损伤。MN（45毫克/千克，腹腔注射）或溶剂（磷酸盐缓冲液，PBS）注射两次：分别在HI损伤前2天和即将进行HI损伤时。在HI损伤后0、1、3、24小时以及14天，从同侧和对侧（仅暴露于缺氧环境）半球提取总RNA，进行逆转录，并使用半定量逆转录聚合酶链反应（RT-PCR），用基因特异性引物扩增巨噬细胞炎性蛋白-1α（MIP-1α）、干扰素诱导蛋白（IP-10）、C-C趋化因子受体5（CCR5；MIP-1α受体）、C-X-C趋化因子受体3（CXCR3；IP-10受体）和IL10。我们发现，在同侧半球，观察到MIP-1α、IP-10、CCR5和CXCR3的mRNA水平显著（P < 0.05）升高。MN治疗降低了CCR5和CXCR3的mRNA水平。相比之下，HI损伤导致抗炎细胞因子IL10的水平显著降低。然而，MN治疗对IL10没有影响。我们得出结论，MN降低了促炎趋化因子受体的表达，但对抗炎细胞因子IL10的表达几乎没有影响。这些作用证实了MN在新生儿HI脑损伤中的抗炎作用。
