1. NIR Laser Photobiomodulation Induces Neuroprotection in an In Vitro Model of Cerebral Hypoxia/Ischemia
- Author
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Elettra Sereni, Daniele Lana, Daniele Nosi, Elisabetta Gerace, Maria Grazia Giovannini, Francesca Cialdai, Monica Monici, and Guido Mannaioni
- Subjects
Male ,0301 basic medicine ,NIR laser ,Neuroscience (miscellaneous) ,Ischemia ,Hippocampal formation ,Hippocampus ,Neuroprotection ,Article ,law.invention ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Organ Culture Techniques ,Oxygen and glucose deprivation ,0302 clinical medicine ,Confocal microscopy ,law ,medicine ,Animals ,Propidium iodide ,Low-Level Light Therapy ,Rats, Wistar ,Neurodegeneration ,Neuroinflammation ,Chemistry ,Neurotoxicity ,Photobiomodulation ,Hypoxia (medical) ,Organotypic hippocampal slices ,medicine.disease ,Rats ,030104 developmental biology ,nervous system ,Microscopy, Fluorescence ,Neurology ,Hypoxia-Ischemia, Brain ,Biophysics ,Female ,Glia activation ,Laser Therapy ,medicine.symptom ,030217 neurology & neurosurgery - Abstract
Brain photobiomodulation (PBM) is an innovative treatment for a variety of neurological conditions, including cerebral ischemia. However, the capability of PBM for ischemic stroke needs to be further explored and its mechanisms of action remain currently unclear. The aim of the present research was to identify a treatment protocol capable of inducing neuroprotection and to investigate the molecular mechanisms activated by a dual-wavelength near infrared (NIR) laser source in an organotypic hippocampal slice model of hypoxia/ischemia. Hippocampal slices were exposed to oxygen and glucose deprivation (OGD) for 30 min followed by NIR laser light (fluence 3.71, 7.42, or 14.84 J/cm2; wavelengths 808 nm and 905 nm) delivered immediately or 30 min or 60 min after OGD, in order to establish a therapeutic window. Neuronal injury was assessed by propidium iodide fluorescence 24 h later. Our results show that NIR laser irradiation attenuates OGD neurotoxicity once applied immediately or 30 min after OGD. Western blot analysis of proteins involved in neuroinflammation (iNOS, COX-2, NFkB subunit p65, and Bcl-2) and in glutamatergic-mediated synaptic activity (vGluT1, EAAT2, GluN1, and PSD95) showed that the protein modifications induced by OGD were reverted by NIR laser application. Moreover, CA1 confocal microscopy revealed that the profound morphological changes induced by OGD were reverted by NIR laser radiation. In conclusion, NIR laser radiation attenuates OGD neurotoxicity in organotypic hippocampal slices through attenuation of inflammatory mechanisms. These findings shed light on molecular definition of NIR neuroprotective mechanisms, thus underlining the potential benefit of this technique for the treatment of cerebral ischemia.
- Published
- 2021