TAT-mediated delivery of neuroglobin attenuates apoptosis induced by oxygen-glucose deprivation via the Jak2/Stat3 pathway in vitro.

Abstract

OBJECTIVES:

Neuroglobin (Ngb), an identified globin in vertebrate brain, is a potential novel protective protein against brain ischemia. In our previous study, the human immunodeficiency virus trans-activator of transcription (TAT) protein transduction domain successfully delivered exogenous Ngb into neurons in the mouse, and protected the brain from cerebral ischemia-induced apoptosis. The aim of this study is to investigate the role of TAT-Ngb in attenuating oxygen-glucose deprivation (OGD) induced apoptosis and to explore the possible mechanism.

METHODS:

Nerve growth factor (NGF)-induced PC12 cells were divided into (1) the control group, (2) the OGD group (just OGD), (3) the Ngb treatment group (OGD and Ngb treatment), and (4) the TAT-Ngb treatment group (OGD and TAT-Ngb treatment). Cell viability and apoptosis were assessed by the MTT assay and the AnnexinV/propidium iodide (PI) staining, respectively. The mitochondrial transmembrane potential was measured by JC-1 staining. Caspase-3, Bcl-2, Bax, Stat3, Jak2, and Akt were determined by western blot analysis.

RESULTS:

Trans-activator of transcription effectively delivered Ngb into NGF-induced PC12 cells. Neuroglobin-mediated neuroprotection rescued cultured cells from OGD. We also confirmed previous findings that TAT-Ngb inhibited mitochondrial apoptosis following OGD. Inhibition of apoptosis by Ac-DEVD-CHO showed that caspase-3 was a crucial factor in OGD-induced apoptosis cascades. AG490, a specific Jak2 inhibitor, attenuated the protective effects of TAT-Ngb. The TAT-Ngb promoted expression of the anti-apoptotic protein Bcl-2 through the Jak2/Stat3 signal pathway, and inhibited apoptosis by blocking caspase-3 activation, while the Jak-Akt-Stat3 signal network was not involved.

CONCLUSION:

Our results demonstrate that TAT-Ngb can protect neuron-like cells against OGD-induced apoptosis by activating the Jak2/Stat3 pathway.

• Authors: Yi Lin, Bin Cai, Xie-Hua Xue, Ling Fang, Zhi-Ying Wu, Ning Wang
• Journal: Neurological research (Neurol Res) Vol. 37 Issue 6 Pg. 531-8 (Jun 2015) ISSN: 1743-1328 [Electronic] England
• PMID: 25023896 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Enzyme Inhibitors
• Nerve Tissue Proteins
• Neuroglobin
• Neuroprotective Agents
• Recombinant Fusion Proteins
• STAT3 Transcription Factor
• Stat3 protein, rat
• Tyrphostins
• alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide
• tat Gene Products, Human Immunodeficiency Virus
• Globins
• Jak2 protein, rat
• Janus Kinase 2
• Glucose

Topics

• Animals
• Apoptosis (drug effects, physiology)
• Blotting, Western
• Cell Hypoxia (drug effects, physiology)
• Cell Survival (drug effects, physiology)
• Drug Delivery Systems
• Enzyme Inhibitors (pharmacology)
• Escherichia coli
• Globins (administration & dosage, genetics)
• Glucose (deficiency)
• Janus Kinase 2 (antagonists & inhibitors, metabolism)
• Membrane Potential, Mitochondrial (drug effects, physiology)
• Nerve Tissue Proteins (administration & dosage, genetics)
• Neuroglobin
• Neuroprotective Agents (administration & dosage)
• PC12 Cells
• Rats
• Recombinant Fusion Proteins (administration & dosage)
• STAT3 Transcription Factor (metabolism)
• Signal Transduction (drug effects)
• Tyrphostins (pharmacology)
• tat Gene Products, Human Immunodeficiency Virus (administration & dosage, genetics)