Background: Postoperative cognitive decline (POCD) is a recognized clinical phenomenon characterized by cognitive impairments in patients following anesthesia and surgery, yet its underlying mechanism remains unclear. Brain-derived neurotrophic factor (BDNF) plays an important role in neuronal plasticity, learning, and memory via activation of TrkB-full length (TrkB-FL) receptors. It has been reported that an abnormal truncation of TrkB mediated by calpain results in dysregulation of BDNF/TrkB signaling and is associated with cognitive impairments in several neurodegenerative disorders. Calpains are Ca-dependent proteases, and overactivation of calpain is linked to neuronal death. Since one source of intracellular Ca is N-methyl-d-aspartate receptors (NMDARs) related and the function of NMDARs can be regulated by neuroinflammation, we therefore hypothesized that dysregulation of BDNF/TrkB signaling mediated by NMDAR/Ca/calpain might be involved in the pathogenesis of POCD.
Methods: In the present study, 16-month-old C57BL/6 mice were subjected to exploratory laparotomy with isoflurane anesthesia to establish the POCD animal model. For the interventional study, mice were treated with either NMDAR antagonist memantine or calpain inhibitor MDL-28170. Behavioral tests were performed by open field, Y maze, and fear conditioning tests from 5 to 8 days post-surgery. The levels of Iba-1, GFAP, interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), NMDARs, calpain, BDNF, TrkB, bax, bcl-2, caspase-3, and dendritic spine density were determined in the hippocampus.
Results: Anesthesia and surgery-induced neuroinflammation overactivated NMDARs and then triggered overactivation of calpain, which subsequently led to the truncation of TrkB-FL, BDNF/TrkB signaling dysregulation, dendritic spine loss, and cell apoptosis, contributing to cognitive impairments in aging mice. These abnormities were prevented by memantine or MDL-28170 treatment.
Conclusion: Collectively, our study supports the notion that NMDAR/Ca2+/calpain is mechanistically involved in anesthesia and surgery-induced BDNF/TrkB signaling disruption and cognitive impairments in aging mice, which provides one possible therapeutic target for POCD.
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http://dx.doi.org/10.1186/s12974-019-1695-x | DOI Listing |
Biol Trace Elem Res
January 2025
Department of Hematology, Affiliated Hospital of Guizhou Medical University, No. 4 Bei Jing Road, Yunyan District, Guiyang, 550004, Guizhou Province, China.
Chronic fluorosis is often accompanied by neurological symptoms, leading to attention, memory and learning ability decline and causing tension, anxiety, depression, and other mental symptoms. In the present study, we analyzed the molecular mechanisms of SIRT1-BDNF regulation of PI3K-AKT, MAPK, and FOXO1A in F-treated BV2 cells. The cytotoxic effect of sodium fluoride (NaF) on BV2 cells was assessed using Cell Counting Kit-8 (CCK-8), crystal violet, and 5-ethynyl-2'-deoxyuridine (EdU) staining.
View Article and Find Full Text PDFBiomed Pharmacother
January 2025
College of Veterinary Medicine, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea. Electronic address:
Rett syndrome (RTT) is a neurological disorder caused by a mutation in the X-linked methyl-CpG binding protein 2 (MECP2), leading to cognitive and motor skill regression. Therapeutic strategies aimed at increasing brain-derived neurotrophic factor (BDNF) levels have been reported; however, BDNF treatment has limitations, including the inability to penetrate the blood-brain barrier, a short half-life, and potential for adverse effects when administered via intrathecal injection, necessitating novel therapeutic approaches. In this study, we focused on the adenosine A receptor (AR), which modulates BDNF and its downstream pathways, and investigated the therapeutic potential of CGS21680, an AR agonist, through in vitro and in vivo studies using R106W RTT model.
View Article and Find Full Text PDFLife (Basel)
December 2024
Department of Pharmacology, Ministry of Health, Derince Education and Research Hospital, 41100 Kocaeli, Türkiye.
Dexmedetomidine (DEX) is a selective alpha-2 adrenergic receptor agonist with sedative and anxiolytic properties. Increasing evidence reports that DEX has a neuroprotective effect. In this study, we investigated the potential effects of DEX on learning and memory functions in rats with experimental cognitive impairment.
View Article and Find Full Text PDFbioRxiv
December 2024
Center for Pain Therapeutics and Addiction Research, School of Dentistry, University of Texas Health San Antonio, Texas, 78229, USA.
Truncated TrkB (TrkBT1), traditionally considered a dominant-negative regulator of full-length TrkB (TrkBTK+), remains poorly understood in peripheral sensory neurons, particularly nociceptors. Furthermore, sensory neuronal TrkB expression and function has been traditionally associated with non-nociceptive neurons, particularly Aδ low-threshold mechanoreceptors. This study challenges prevailing assumptions by demonstrating that TrkBT1 is the predominant TrkB isoform expressed in sensory neurons and plays a functional role in modulating neuronal activity.
View Article and Find Full Text PDFPharmacol Res
January 2025
School of Clinical Medicine and Basic Medical Science, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250000, China; The Second Affiliated Hospital of Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271000, China. Electronic address:
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