Abstract
Aging is often accompanied by exacerbated activation of cell death-related signaling pathways and decreased energy metabolism. We hypothesized that transcranial near-infrared laser may increase intracellular signaling pathways beneficial to aging brains, such as those that regulate brain cell proliferation, apoptosis, and energy metabolism. To test this hypothesis, we investigated the expression and activation of intracellular signaling proteins in the cerebral cortex and hippocampus of aged rats (20 months old) treated with the transcranial near-infrared laser for 58 consecutive days. As compared to sham controls, transcranial laser treatment increased intracellular signaling proteins related to cell proliferation and cell survival, such as signal transducer and activator of transcription 3 (STAT3), extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), p70 ribosomal protein S6 kinase (p70S6K) and protein kinase B (PKB), also known as Akt that is linked to glucose metabolism. In addition, ERK is linked to memory, while ERK and JNK signaling pathways regulate glucose metabolism. Specifically, the laser treatment caused the activation of STAT3, ERK, and JNK signaling proteins in the cerebral cortex. In the hippocampus, the laser treatment increased the expression of p70S6K and STAT3 and the activation of Akt. Taken together, the data support the hypothesis that transcranial laser photobiomodulation improves intracellular signaling pathways linked to cell survival, memory, and glucose metabolism in the brain of aged rats.
Highlights
In the world, the number of people aged 60 and over has been growing faster than any age group (Desa, 2015)
The expression and activation of signaling proteins linked to cell growth, proliferation, and survival, as Akt, p70S6K and extracellular signal-regulated protein kinase (ERK), are decreased in the brain of aged rats, including the hippocampal formation, a brain region linked to certain mnemonic processes (Jin et al, 2008)
No significant difference between the groups studied was observed in the cortical expression of Akt (U = 8.000; p = 0.201), p70S6K (U = 12.000, p = 0.584), signal transducer and activator of transcription 3 (STAT3) (U = 11.000; p = 0.465), signal transducer and activator of transcription 5 (STAT5) (U = 12.000; p = 0.584), ERK (U = 13.000; p = 0.715), Jun N-terminal kinase (JNK) (U = 9.000; p = 0.273) and p38 (U = 5.000; p = 0.068)
Summary
The number of people aged 60 and over has been growing faster than any age group (Desa, 2015). The expression and activation of signaling proteins linked to cell growth, proliferation, and survival, as Akt, p70S6K and extracellular signal-regulated protein kinase (ERK), are decreased in the brain of aged rats, including the hippocampal formation, a brain region linked to certain mnemonic processes (Jin et al, 2008). Activation and expression of intracellular signaling proteins linked to apoptosis, such as c-Jun N-terminal kinase (JNK) and p38, are increased in the hippocampus of aged rats (O’Donnell et al, 2000). After glucose is transported inside cells, it can fuel mitochondrial respiration for ATP production during oxidative energy metabolism (Gonzalez-Lima et al, 2014). In this sense, the search for new therapies for the treatment or prevention of age-related harm is necessary for the medical society
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
