RLj-RGD3, a Novel Three-RGD-Motif-Containing Recombinant Protein from Lampetra japonica, Protects PC12 Cells from Injury Induced by Oxygen-Glucose Deprivation and Reperfusion.

Li Lv,Fangyu Shao,Qingwei Li,Weiping Li,Jihong Wang,Qin Zhou,Qian Lu

doi:10.1155/2016/6701249

Abstract

rLj-RGD3 is a 14.5 kDa recombinant protein with 3 RGD (Arg-Gly-Asp) motifs from the salivary gland secretions of Lampetra japonica, which is a histidine-rich and arginine-rich protein. Previous reports indicated that rLj-RGD3 has typical functions of RGD-toxin protein, such as platelet aggregation suppression tumour metastasis and angiogenesis inhibition. Because histidine and arginine have cerebral ischemia-reperfusion and neuroprotective functions, we investigated whether rLj-RGD3 has such activities and studied the mechanism. The effects of rLj-RGD3 on neuroprotection and antiapoptosis were determined. The expression level of focal adhesion kinase (FAK), p-FAK, Caspase-3, and Bcl-2 after oxygen-glucose deprivation and reperfusion (OGD-R) was examined. The viability of PC12 cells incubated with rLj-RGD3 at high concentrations (16 μmol/L) increased significantly due to its ability to protect the cells from apoptosis after OGD-R-induced injury. Furthermore, rLj-RGD3 attenuated the damage due to OGD-R. Most of the PC12 cells were apoptotic after OGD-R. In contrast, the number of apoptotic PC12 cells was significantly decreased in the group treated with a high-dose of rLj-RGD3. In addition, rLj-RGD3 activated FAK and p-FAK protein. rLj-RGD3 inhibited Caspase-3 and upregulated Bcl-2 protein expression in PC12 cells after OGD-R. The study provides the first evidence for neuroprotective effects of rLj-RGD3 in ischemic injury that may be partly mediated through inhibition of Caspase-3 and upregulation of Bcl-2, FAK, and p-FAK protein expression.

Highlights

Ischemic stroke, commonly known as cerebral infarction, is a cerebral insufficiency caused by the brain tissue ischemia and hypoxia associated with the clinical syndrome
Because histidine and arginine have cerebral ischemia-reperfusion and neuroprotective functions, we investigated whether rLj-RGD3 has such activities on the focal cerebral ischemia and studied the mechanism, such as the role of focal adhesion kinase (FAK) in the regulation of the integrin-PI3K/Akt pathway by rLj-RGD3 in the OGD-Rinduced PC12 cells damage model
The histidine-rich and arginine-rich characteristics of Lj-RGD3 suggested that it will have the functions of cerebral ischemiareperfusion and neuroprotection

Summary

Introduction

Commonly known as cerebral infarction, is a cerebral insufficiency caused by the brain tissue ischemia and hypoxia associated with the clinical syndrome. The integrin family of cell adhesion molecules primarily mediates the adhesion between cells and between the cells and the extracellular matrix (ECM), as well as inducing bidirectional signalling between the ECM and cells [2]. Integrin-mediated adhesion regulates many cell functions such as apoptosis [3], proliferation, adhesion, and migration [4], including lymphocyte homing. Specific binding sites between extracellular matrix proteins and the integrin receptors have been identified, namely, the arginineglycine-aspartic sequence (Arg-Gly-Asp, RGD). A polypeptide containing the RGD sequence can recognise the integrin receptor and bind to it, thereby influencing cellular biological functions [5]

Methods

Results

Discussion

Conclusion