Polyethylene Glycol Protects Injured Neuronal Mitochondria

Abstract

Objective: Polyethylene glycol (PEG), a hydrophilic polymer, can immediately repair neuronal membranes and inhibit free radical production following trauma. The aim of this study is to examine whether PEG can directly repair mitochondria in the event of trauma. Method: Purified brain mitochondria from guinea pigs were used. Mitochondrial function was assessed by biochemical methods and structural changes were observed by both fluorescence light microscopy and coherent anti-Stokes Raman scattering microscopy. Results: We present evidence suggesting that PEG is capable of directly reducing injury to mitochondria independent of plasma membrane repair. Specifically, the suppression of oxygen consumption rate of purified mitochondria due to H₂O₂ and/or calcium can be significantly reversed by 12.5 mM PEG. PEG also significantly reduced mitochondrial swelling due to similar injury. Furthermore, we have shown that such PEG-mediated mitochondrial protection is dependent on the molecular weight of PEG, suggesting a direct physical blockade of mitochondrial permeability transitional pore by PEG. Conclusion: These findings, coupled with previous evidence that PEG enters the cytosol following mechanical trauma, strongly indicate that there are at least 2 avenues of PEG-mediated cytoprotection in mechanically injured spinal cords: repair of plasma membrane and protection of mitochondria.

‘Poly(ethylene glycol)-magnetic nanoparticles-curcumin’ trio: Directed morphogenesis and synergistic free-radical scavenging

“…It has been recently reported that curcumin has in vitro cytoprotective role and it also reduces replication of the Japanese Encephalitis Virus [33]. Survey of literature reveals that poly(ethylene glycol) (PEG) can immediately repair neuronal membranes and inhibit rather than scavenge free-radical production following trauma [34]. High biocompatibility and nonadhesive properties that arise from steric stabilizing effects at bio-interfaces, highly dynamic motion, and extended chain conformation [35,36] makes poly(ethylene glycol) (PEG) an ideal polymer to coat MNPs for bio-medical applications.…”

Survival, proliferation and differentiation enhancement of neural stem cells cultured in three-dimensional polyethylene glycol-RGD hydrogel with tenascin

“…While PEG–RGD was reported to increase viability (Liu et al, ), this study shows that the presence of RGD and tenascin C improves the viability (~97%) of the cells, which agrees with previous reports (Cotman et al, ; Nakaji‐Hirabayashi et al, ). Moreover, PEG, a hydrophilic polymer, was reported to protect the neuron from free radicals, repair neuronal membranes (Chen et al, ) and protect membrane integrity (Shi, ). This indicates that they may interact in a synergistic mode; accordingly, a similar effect could operate in neuronal differentiation as a result of the effect of both RGD (Jurga et al, ; Yun et al, ) and tenascin C (Franco and Muller, ).…”

“…Therefore, it seems essential to apply methods that increase the survival and proliferation of the transplanted NSCs. One approach is to use cell carriers such as polyethylene glycol (PEG), because it could improve neuronal membrane repair, inhibit free radical production (Chen et al, ) and reduce apoptosis (Luo and Shi, ). Moreover, PEG has a mechanical property that can contribute to the repair of the damaged membrane (Koob et al, ), low antigenicity and the ability to transfer oxygen and nutrients to the cultured cells (Hutson et al, ).…”

Chemical contrast for imaging living systems: molecular vibrations drive CARS microscopy

“…It is well known that metabolism is affected during the development of various types of cancer, and CARS microscopy has recently emerged as a way to image these nonstatic changes 51 . CARS microscopy has also proven to be an important tool for imaging neurons and brain slices as well as investigating diseased states associated with demyelination [52][53][54][55][56][57][58] . This tool has also been used to investigate stem cell differentiation 59 , host-pathogen interactions 39,43,48,[60][61][62][63][64][65] and the effects of drugs on target cells and tissues 38,40,43,53,[66][67][68][69] .…”