[Adenosine Al Receptor Mediated Neuroprotection of Shenmai Injection on Rat Cerebral Ischemia/Reperfusion Injury: an Experimental Study].

OBJECTIVE: To observe whether adenosine Al receptor (Al R) mediated neuroprotection of Shenmai Injection (SI) on rat cerebral ischemia/reperfusion (I/R) injury. METHODS: The focal cerebral I/R model was established by middle cerebral artery occlusion (MCAO). Totally 60 successfully modeled rats was divided into 5 groups according to randomized block principle, i.e., the model group, the SI group, the SI + AlR antagonist (1,3-dipropyl-8-cyclopentylxanthine, DPCPX) group, the AlR antagonist control group, and the dimethyl sulfoxide (DMSO) control group, 12 in each group. Besides, a sham-operation group was set up (n =12). SI at 15 mL/kg was peritoneally injected to mice in the SI group immediately after cerebral I/R. Equal volume of normal saline was injected to mice in the model group and the sham-operation group. DPCPX at 1 mg/mL was peritoneally injected to mice in the Al R antagonist control group 30 min before peritoneal injecting SI. DPCPX at 1 mg/kg and DMSO at 1 mL/kg were peritoneally injected to mice in the AlR antagonist control group and the DMSO control group 30 min immediately before cerebral I/R. Rats' neurobehavioral scores were assessed after 24 h reperfusion. The volume of cerebral infarction and Bcl-2 protein expression of cerebral infarction penumbra were also detected. Results Compared with the sham-operation group, neurobehavioral scores, the volume of cerebral infarction, and Bcl-2 protein expression increased (all P <0. 05). Compared with the model group, neurobehavioral scores and the volume of cerebral infarction obviously decreased, but Bcl-2 protein expression increased in the SI group (all P <0. 05). Compared with the SI group, neurobehavioral scores increased, the volume of cerebral infarction was obviously enlarged, and Bcl-2 protein expression was obviously reduced in the A1R antagonist control group (all P <0. 05). CONCLUSIONS: SI's neurobehavioral scores could be partially reversed in the Al R antagonist control group, the volume of cerebral infarction and Bcl-2 protein expression improved. AlR might possibly meditate neuroprotection of SI on MACO mire

Silencing airway epithelial cell-derived hepcidin exacerbates sepsis induced acute lung injury.

INTRODUCTION: The production of antimicrobial peptides by airway epithelial cells is an important component of the innate immune response to pulmonary infection and inflammation. Hepcidin is a ß-defensin-like antimicrobial peptide and acts as a principal iron regulatory hormone. Hepcidin is mostly produced by hepatocytes, but is also expressed by other cells, such as airway epithelial cells. However, nothing is known about its function in lung infectious and inflammatory diseases. We therefore sought to investigate the role of airway epithelial cell-derived hepcidin in sepsis-induced acute lung injury. METHODS: Acute lung injury was induced by polymicrobial sepsis via cecal ligation and puncture (CLP) surgery. Adenovirus-mediated short hairpin RNA specific for the mouse hepcidin gene hepc1 and control adenovirus were intratracheally injected into mice. The adenovirus-mediated knockdown of hepcidin in airway epithelial cells was evaluated in vivo. Lung injury and the 7-day survival rate were assessed. The levels of hepcidin-related iron export protein ferroportin were measured, and the iron content and function of alveolar macrophages were evaluated. RESULTS: The hepcidin level in airway epithelial cells was upregulated during polymicrobial sepsis. The knockdown of airway epithelial cell-derived hepcidin aggravated the polymicrobial sepsis-induced lung injury and pulmonary bacterial infection and increased the mortality (53.33% in Ad-shHepc1 treated mice versus 12.5% in Ad-shNeg treated mice, P <0.05). The knockdown of hepcidin in airway epithelial cells also led to reduced ferroportin degradation and a low intracellular iron content in alveolar macrophages. Moreover, alveolar macrophages form the airway epithelial cell-derived hepcidin knockdown mice showed impaired phagocytic ability than those from the control mice. CONCLUSIONS: Airway epithelial cell-derived hepcidin plays an important role in CLP induced acute lung injury. The severe lung injury in the airway epithelial cell-derived hepcidin knockdown mice is at least partially related to the altered intracellular iron level and function of alveolar macrophages.

GPR17 mediates ischemia-like neuronal injury via microglial activation.

GPR17 is a G (i)-coupled dual receptor, linked to P2Y and CysLT receptors stimulated by uracil nucleotides and cysteinyl leukotrienes, respectively. Recent evidence has demonstrated that GPR17 inhibition ameliorates the progression of cerebral ischemic injury by regulating neuronal death and microglial activation. The present study aimed to assess the detailed regulatory roles of this receptor in oxygen­glucose deprivation/recovery (OGD/R)­induced ischemia­like injury in vitro and explore the underlying mechanism. The results demonstrated that OGD/R induced ischemic neuronal injury and microglial activation, including enhanced phagocytosis and increased inflammatory cytokine release in neuron­glial mixed cultures of cortical cells. GPR17 upregulation during OGD/R was spatially and temporally correlated with neuronal injury and microglial activation. In addition, GPR17 knockdown inhibited OGD/R­induced responses in neuron­glial mixed cultures. GPR17 knockdown also attenuated cell injury induced by the agonist leukotriene D4 (LTD4) or uridine 5'­diphosphate (UDP) in neuron­glial mixed cultures. However, GPR17 knockdown did not affect OGD/R­induced ischemic neuronal injury in primary cultures of neurons. In primary astrocyte cultures, neither GPR17 nor OGD/R induced injury. By contrast, GPR17 knockdown ameliorated OGD/R­induced microglial activation, boosting phagocytosis and inflammatory cytokine release in primary microglia cultures. Finally, the results demonstrated that the conditioned medium of microglia pretreated with OGD/R induced neuronal death, and the neuronal injury was significantly inhibited by GPR17 knockdown. These findings suggested that GPR17 may mediate ischemia­like neuronal injury and microglial activation in vitro; however, the protective effects on ischemic neuronal injury might depend upon microglial activation. Whether GPR17 regulates neuronal injury mediated by oligodendrocyte linkage remains to be investigated.