Tat‐Hsp70 protects dopaminergic neurons in midbrain cultures and in the substantia nigra in models of Parkinson’s disease

Abstract

Parkinson’s disease is characterized by the progressive loss of dopaminergic (DA) neurons in the substantia nigra. The heat‐shock protein 70 (Hsp70) reduces protein misfolding and aggregation. It has been shown to protect cells against oxidative stress and apoptotic stimuli in various neurodegenerative disease models. To deliver Hsp70 across cellular membranes and into the brain, we linked it to a cell‐penetrating peptide derived from the HIV trans‐activator of transcription (Tat) protein. In vitro, Tat‐Hsp70 transduced neuroblastoma cells and protected primary mesencephalic DA neurons and their neurites against MPP+‐mediated degeneration. In vivo, the systemic application of cell‐permeable Hsp70 protected DA neurons of the substantia nigra pars compacta against subacute toxicity of MPTP. Furthermore, Tat‐Hsp70 diminished the MPTP induced decrease in DA striatal fiber density. Thus, we demonstrate that systemically applied Tat‐Hsp70 effectively prevents neuronal cell death in in vitro and in vivo models of Parkinson’s disease. The use of Tat‐fusion proteins might therefore be a valuable tool to deliver molecular chaperones like Hsp70 into the brain and may be the starting point for new protective strategies in neurodegenerative diseases.

Functional Protein Delivery into Neurons Using Polymeric Nanoparticles

“…In culture, neurons are difficult to transfect at high efficiency (32). Methods for direct protein delivery exist, but they generally require either manipulation of the protein sequence or direct injection of the protein (33). In vivo protein delivery is even more challenging, because the BBB prevents access of most large molecules to the brain parenchyma (6).…”

TAT-Hsp70 Induces Neuroprotection Against Stroke Via Anti-Inflammatory Actions Providing Appropriate Cellular Microenvironment for Transplantation of Neural Precursor Cells

“…According to this procedure, TAT-Hsp70 is highly stable after cell transduction as no protein degradation is detected 24 hours after protein application, suggesting that the intracellular half-life time is at least a few days. 12 Adult Subventricular Zone-Derived Neural Precursor Cells Neural precursor cells were isolated from the SVZ of 6 to 8-week old male transgenic green fluorescence protein positive (GFP þ ) animals (C57BL/6-Tg ACTB-EGFP, 1Osb/J; JAX Laboratory, Bar Harbor, ME, USA) as described. 14 The SVZ was microdissected under stereomicroscopic control (Zeiss, Jena, Germany) and minced into small pieces, followed by mechanical trituration and dissociation into a single-cell suspension.…”

Transduction of Neural Precursor Cells with TAT-Heat Shock Protein 70 Chaperone: Therapeutic Potential Against Ischemic Stroke after Intrastriatal and Systemic Transplantation

“…In order to promote survival of grafted cells, NPCs were protein-transduced with the chaperone Hsp70, which reduces apoptosis and inflammation after hypoxic-ischemic injury [23,24]. Since cellular entry of Hsp70 is poor, transduction was achieved in vitro using the membrane-permeable and neuroprotective TAT-Hsp70 fusion protein before transplantation [10,35]. This study has explicit meaning for future cell-based stroke therapies, since it highlights the importance of cell transplantation routes, implying different mechanisms by which transplanted NPCs induce poststroke neuroprotection.…”