Roles of Exosomes and Exosomal MicroRNAs in Postoperative Sleep Disturbance

Role of dexmedetomidine in postoperative cognitive dysfunction and sleep improvement in aged rats by regulating the PI3K/Akt signaling pathway and its mechanism

OBJECTIVE

This study aims to explore the mechanism of dexmedetomidine (Dex) in improving postoperative cognitive dysfunction (POCD) and postoperative sleep in aged rats through the PI3K/Akt signaling pathway.

METHODS

Splenectomy was used to establish a POCD model in aged rats. Open field test (OFT) and new object recognition test (NORT) were used to observe the cognitive function of rats The awakening and sleep times of rats were recorded. Hematoxylin-eosin, Nissl, and TUNEL staining were adopted to examine histopathological alterations, neuronal cell damage, and apoptosis, respectively; western blot to detect the activation of the PI3K/Akt signaling pathway and the protein level of apoptosis factors Bcl-2, Bax, and cleaved caspase-3; enzyme-linked immunosorbent assay to quantify the concentrations of inflammatory factors IL-6, IL-1β, and TNF-α.

RESULTS

On days 1, 7, and 14 post-splenectomy surgery, aged rats exhibited shortened moving distance in OFT, reduced discrimination rate in NORT, prolonged awakening time, and shortened sleep time, while such effect was reversed by further Dex treatment. In addition, neuronal damage, inflammatory response, and apoptosis occurred in the hippocampal CA1 area in aged rats but can be attenuated by Dex treatment. Dex triggered the activation of the PI3K/Akt signaling pathway in the hippocampus in aged rats after surgery, and inhibition of the PI3K/Akt signaling pathway can result in a partial reversal of the alleviating effects observed with Dex treatment.

CONCLUSION

Dex improves POCD and postoperative sleep in aged rats by activating the PI3K/Akt signaling pathway to reduce inflammatory response and apoptosis in the hippocampal CA1 area.

MiR-184 Mediated the Expression of ZNF865 in Exosome to Promote Procession in the PD Model

Exosomes are nanoscale small vesicles (EVs) secreted by cells that carry important bio information, including proteins, miRNAs, and more. Exosome contents are readily present in body fluids, including blood, and urine of humans and animals, and thereby act as markers of diseases. In patients with Parkinson's disease (PD), exosomes may spread alpha-synuclein and miR-184 between the cells contributing to dopaminergic neuronal loss. In this study, we detected the levels of miR-184 in urine-excreted neuronal exosomes between PD patients and age-matched healthy subjects by qRT-PCR analysis. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were also used to determine the ultracellular structures of exosomes nanoparticles. MPP + and MPTP were used to construct the cell and animal PD model. Behavioral tests were used to detect motor performance. Furthermore, the cytological experiments were measured to examine the relationship between miR-184 and ZNF865. We found that the levels of miR-184 in urine-derived neuronal exosomes from PD patients were higher, compared to aged-matched normal people. The exosomes from PD patients were larger with greater numbers than those from the age-matched healthy subjects. The difference in miR-184 in urinary exosomes between PD patients and normal people may provide a novel perspective for early diagnosis of PD. However, no difference in CD63 level was observed in Exo-control and Exo-PD groups (exosome from control or PD groups). Moreover, ZNF865 was detected as the targeted gene of miR-184. In addition, miR-184 ASO (miR-184 antisense oligodeoxynucleotide, miR-184 ASO) could rescue the damage of neuronal apoptosis and motor performance in PD mice. Our results showed the miR-184 potential to function as a diagnostic marker of PD.

The impact of aging and oxidative stress in metabolic and nervous system disorders: programmed cell death and molecular signal transduction crosstalk

Life expectancy is increasing throughout the world and coincides with a rise in non-communicable diseases (NCDs), especially for metabolic disease that includes diabetes mellitus (DM) and neurodegenerative disorders. The debilitating effects of metabolic disorders influence the entire body and significantly affect the nervous system impacting greater than one billion people with disability in the peripheral nervous system as well as with cognitive loss, now the seventh leading cause of death worldwide. Metabolic disorders, such as DM, and neurologic disease remain a significant challenge for the treatment and care of individuals since present therapies may limit symptoms but do not halt overall disease progression. These clinical challenges to address the interplay between metabolic and neurodegenerative disorders warrant innovative strategies that can focus upon the underlying mechanisms of aging-related disorders, oxidative stress, cell senescence, and cell death. Programmed cell death pathways that involve autophagy, apoptosis, ferroptosis, and pyroptosis can play a critical role in metabolic and neurodegenerative disorders and oversee processes that include insulin resistance, β-cell function, mitochondrial integrity, reactive oxygen species release, and inflammatory cell activation. The silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), AMP activated protein kinase (AMPK), and Wnt1 inducible signaling pathway protein 1 (WISP1) are novel targets that can oversee programmed cell death pathways tied to β-nicotinamide adenine dinucleotide (NAD+), nicotinamide, apolipoprotein E (APOE), severe acute respiratory syndrome (SARS-CoV-2) exposure with coronavirus disease 2019 (COVID-19), and trophic factors, such as erythropoietin (EPO). The pathways of programmed cell death, SIRT1, AMPK, and WISP1 offer exciting prospects for maintaining metabolic homeostasis and nervous system function that can be compromised during aging-related disorders and lead to cognitive impairment, but these pathways have dual roles in determining the ultimate fate of cells and organ systems that warrant thoughtful insight into complex autofeedback mechanisms.

Cognitive Impairment in Multiple Sclerosis

Almost three million individuals suffer from multiple sclerosis (MS) throughout the world, a demyelinating disease in the nervous system with increased prevalence over the last five decades, and is now being recognized as one significant etiology of cognitive loss and dementia. Presently, disease modifying therapies can limit the rate of relapse and potentially reduce brain volume loss in patients with MS, but unfortunately cannot prevent disease progression or the onset of cognitive disability. Innovative strategies are therefore required to address areas of inflammation, immune cell activation, and cell survival that involve novel pathways of programmed cell death, mammalian forkhead transcription factors (FoxOs), the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), the silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), and associated pathways with the apolipoprotein E (APOE-ε4) gene and severe acute respiratory syndrome coronavirus (SARS-CoV-2). These pathways are intertwined at multiple levels and can involve metabolic oversight with cellular metabolism dependent upon nicotinamide adenine dinucleotide (NAD+). Insight into the mechanisms of these pathways can provide new avenues of discovery for the therapeutic treatment of dementia and loss in cognition that occurs during MS.

The potential value of exosomes as adjuvants for novel biologic local anesthetics

The side effects of anesthetic drugs are a key preoperative concern for anesthesiologists. Anesthetic drugs used for general anesthesia and regional blocks are associated with a potential risk of systemic toxicity. This prompted the use of anesthetic adjuvants to ameliorate these side effects and improve clinical outcomes. However, the adverse effects of anesthetic adjuvants, such as neurotoxicity and gastrointestinal reactions, have raised concerns about their clinical use. Therefore, the development of relatively safe anesthetic adjuvants with fewer side effects is an important area for future anesthetic drug research. Exosomes, which contain multiple vesicles with genetic information, can be released by living cells with regenerative and specific effects. Exosomes released by specific cell types have been found to have similar effects as many local anesthetic adjuvants. Due to their biological activity, carrier efficacy, and ability to repair damaged tissues, exosomes may have a better efficacy and safety profile than the currently used anesthetic adjuvants. In this article, we summarize the contemporary literature about local anesthetic adjuvants and highlight their potential side effects, while discussing the potential of exosomes as novel local anesthetic adjuvant drugs.

Effects of LncRNA GAS5/miR-137 general anesthesia on cognitive function by TCF4 inflammatory bodies in patients undergoing lumbar spinal canal decompression

Lumbar spinal stenosis is a common orthopedic disease in clinical practice at present. Postoperative cognitive dysfunction (POCD) refers to the phenomenon of impaired memory. However, whether long noncoding RNA (LncRNA) GAS5 contributes to the mechanism of cognitive function in undergoing lumbar spinal canal decompression remains unknown. Thus, the present study investigated the precise details of LncRNA GAS5 involvement in Postoperative cognitive dysfunction of patients undergoing lumbar spinal canal decompression. Patients undergoing lumbar spinal canal decompression with cognitive function and Normal healthy volunteers were obtained. C57BL/6 mice were maintained with a 2% concentration of sevoflurane in 100% oxygen at a flow rate of 2 L minute-1 for 4 hours. LncRNA GAS5 gene expression were up-regulated in patients undergoing lumbar spinal canal decompression. In mice model, LncRNA GAS5 gene expression also increased. LncRNA GAS5 promoted neuroinflammation in vitro model. LncRNA GAS5 raised cognitive impairment and increased neuroinflammation in mice model. LncRNA GAS5 suppressed miR-137 in vitro model. MiR-137 reduced neuroinflammation in vitro model. MiR-137 suppressed TCF4 protein expression in vitro model. Transcription factor TCF4 activates the expression of bHLH. Taking together, this experiment provide the first experimental and clinical evidence that LncRNA GAS5/miR-137 promoted anesthesia-induced cognitive function to increase inflammatory bodies in patients undergoing lumbar spinal canal decompression, suggesting it may be a biomarker of POCD and a potential therapeutic target for POCD.

Effects of exosomal miRNAs in the diagnosis and treatment of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease. Exosomes are extracellular vesicles secreted by a variety of cells, and they participate in intercellular communication by transferring microRNA (miRNA) and other substances. Among the various internal and external factors involved in the occurrence and development of AD, exosome-derived miRNAs have become essential in the pathogenesis and treatment of AD. As nanocarriers of miRNA, exosomes are expected to become an important tool in the pathogenesis, diagnosis, and treatment of AD. This article reviews the roles of exosomal miRNAs in the pathophysiological process, diagnostic biomarkers and treatment of AD.