miR-590-3 and SP1 Promote Neuronal Apoptosis in Patients with Alzheimer's Disease via AMPK Signaling Pathway

MicroRNAs Modulating Neuroinflammation in Parkinson's disease

Parkinson's disease (PD) is one of the most frequent age-associated neurodegenerative disorder. Presence of α-synuclein-containing aggregates in the substantia nigra pars compacta (SNpc) and loss of dopaminergic (DA) neurons are among the characteristic of PD. One of the hallmarks of PD pathophysiology is chronic neuroinflammation. Activation of glial cells and elevated levels of pro-inflammatory factors are confirmed as frequent features of the PD brain. Chronic secretion of pro-inflammatory cytokines by activated astrocytes and microglia exacerbates DA neuron degeneration in the SNpc. MicroRNAs (miRNAs) are among endogenous non-coding small RNA with the ability to perform post-transcriptional regulation in target genes. In that regard, the capability of miRNAs for modulating inflammatory signaling is the center of attention in many investigations. MiRNAs could enhance or limit inflammatory signaling, exacerbating or ameliorating the pathological consequences of extreme neuroinflammation. This review summarizes the importance of inflammation in the pathophysiology of PD. Besides, we discuss the role of miRNAs in promoting or protecting neural cell injury in the PD model by controlling the inflammatory pathway. Modifying the neuroinflammation by miRNAs could be considered a primary therapeutic strategy for PD.

Mechanism and Therapeutic Prospect of miRNAs in Neurodegenerative Diseases

MicroRNAs (miRNAs) are the smallest class of noncoding RNAs, which widely exist in animals and plants. They can inhibit translation or overexpression by combining with mRNA and participate in posttranscriptional regulation of genes, resulting in reduced expression of target proteins, affecting the development, growth, aging, metabolism, and other physiological and pathological processes of animals and plants. It is a powerful negative regulator of gene expression. It mediates the information exchange between different cellular pathways in cellular homeostasis and stress response and regulates the differentiation, plasticity, and neurotransmission of neurons. In neurodegenerative diseases, in addition to the complex interactions between genetic susceptibility and environmental factors, miRNAs can serve as a promising diagnostic tool for diseases. They can also increase or reduce neuronal damage by regulating the body's signaling pathways, immune system, stem cells, gut microbiota, etc. They can not only affect the occurrence of diseases and exacerbate disease progression but also promote neuronal repair and reduce apoptosis, to prevent and slow down the development of diseases. This article reviews the research progress of miRNAs on the mechanism and treatment of neurodegenerative diseases in the nervous system. This trial is registered with NCT01819545, NCT02129452, NCT04120493, NCT04840823, NCT02253732, NCT02045056, NCT03388242, NCT01992029, NCT04961450, NCT03088839, NCT04137926, NCT02283073, NCT04509271, NCT02859428, and NCT05243017.

NLRP3 Inflammasome’s Activation in Acute and Chronic Brain Diseases—An Update on Pathogenetic Mechanisms and Therapeutic Perspectives with Respect to Other Inflammasomes

Increasingly prevalent acute and chronic human brain diseases are scourges for the elderly. Besides the lack of therapies, these ailments share a neuroinflammation that is triggered/sustained by different innate immunity-related protein oligomers called inflammasomes. Relevant neuroinflammation players such as microglia/monocytes typically exhibit a strong NLRP3 inflammasome activation. Hence the idea that NLRP3 suppression might solve neurodegenerative ailments. Here we review the recent Literature about this topic. First, we update conditions and mechanisms, including RNAs, extracellular vesicles/exosomes, endogenous compounds, and ethnic/pharmacological agents/extracts regulating NLRP3 function. Second, we pinpoint NLRP3-activating mechanisms and known NLRP3 inhibition effects in acute (ischemia, stroke, hemorrhage), chronic (Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, MS, ALS), and virus-induced (Zika, SARS-CoV-2, and others) human brain diseases. The available data show that (i) disease-specific divergent mechanisms activate the (mainly animal) brains NLRP3; (ii) no evidence proves that NLRP3 inhibition modifies human brain diseases (yet ad hoc trials are ongoing); and (iii) no findings exclude that concurrently activated other-than-NLRP3 inflammasomes might functionally replace the inhibited NLRP3. Finally, we highlight that among the causes of the persistent lack of therapies are the species difference problem in disease models and a preference for symptomatic over etiologic therapeutic approaches. Therefore, we posit that human neural cell-based disease models could drive etiological, pathogenetic, and therapeutic advances, including NLRP3’s and other inflammasomes’ regulation, while minimizing failure risks in candidate drug trials.

Sevoflurane Postconditioning Attenuates Cerebral Ischemia-Reperfusion Injury by Inhibiting SP1/ACSL4-Mediated Ferroptosis

Sevoflurane is the most commonly used anesthetic in clinical practice and exerts a protective effect on cerebral ischemia-reperfusion (I/R) injury. This study aims to elucidate the molecular mechanism by which sevoflurane postconditioning protects against cerebral I/R injury. Oxygen-glucose deprivation/reperfusion (OGD/R) model in vitro and the middle cerebral artery occlusion (MCAO) model in vivo were established to simulate cerebral I/R injury. Sevoflurane postconditioning reduced neurological deficits, cerebral infarction, and ferroptosis after I/R injury. Interestingly, sevoflurane significantly inhibited specificity protein 1 (SP1) expression in MACO rats and HT22 cells exposed to OGD/R. SP1 overexpression attenuated the neuroprotective effects of sevoflurane on OGD/R-treated HT22 cells, evidenced by reduced cell viability, increased apoptosis, and cleaved caspase-3 expression. Furthermore, chromatin immunoprecipitation and luciferase experiments verified that SP1 bound directly to the ACSL4 promoter region to increase its expression. In addition, sevoflurane inhibited ferroptosis via SP1/ACSL4 axis. Generally, our study describes an anti-ferroptosis effect of sevoflurane against cerebral I/R injury via downregulating the SP1/ASCL4 axis. These findings suggest a novel sight for cerebral protection against cerebral I/R injury and indicate a potential therapeutic approach for a variety of cerebral diseases.

Altered glucose metabolism in Alzheimer's disease: Role of mitochondrial dysfunction and oxidative stress

Increasing evidence suggests that abnormal cerebral glucose metabolism is largely present in Alzheimer's disease (AD). The brain utilizes glucose as its main energy source and a decline in its metabolism directly reflects on brain function. Weighing on recent evidence, here we systematically assessed the aberrant glucose metabolism associated with amyloid beta and phosphorylated tau accumulation in AD brain. Interlink between insulin signaling and AD highlighted the involvement of the IRS/PI3K/Akt/AMPK signaling, and GLUTs in the disease progression. While shedding light on the mitochondrial dysfunction in the defective glucose metabolism, we further assessed functional consequences of AGEs (advanced glycation end products) accumulation, polyol activation, and other contributing factors including terminal respiration, ROS (reactive oxygen species), mitochondrial permeability, PINK1/parkin defects, lysosome-mitochondrial crosstalk, and autophagy/mitophagy. Combined with the classic plaque and tangle pathologies, glucose hypometabolism with acquired insulin resistance and mitochondrial dysfunction potentiate these factors to exacerbate AD pathology. To this end, we further reviewed AD and DM (diabetes mellitus) crosstalk in disease progression. Taken together, the present work discusses the emerging role of altered glucose metabolism, contributing impact of insulin signaling, and mitochondrial dysfunction in the defective cerebral glucose utilization in AD.

Exploring Early Physical Examination Diagnostic Biomarkers for Alzheimer’s Disease Based on Least Absolute Shrinkage and Selection Operator

Neurodegenerative diseases such as Alzheimer’s disease (AD) are an increasing public health challenge. There is an urgent need to shift the focus to accurate detection of clinical AD at the physical examination stage. The purpose of this study was to identify biomarkers for AD diagnosis. Differential expression analysis was performed on a dataset including prefrontal cortical samples and peripheral blood samples of AD to identify shared differentially expressed genes (DEGs) shared between the two datasets. In addition, a minimum absolute contraction and selection operator (LASSO) model based on shared-DEGs identified nine signature genes (MT1X, IGF1, DLEU7, TRIM36, PTPRC, WNK2, SPG20, C8orf59, and BRWD1) that accurately predict AD occurrence. Enrichment analysis showed that the signature gene was significantly associated with the AD-related p53 signaling pathway, T-cell receptor signaling pathway, HIF-1 signaling pathway, AMPK signaling pathway, and FoxO signaling pathway. Thus, our results identify not only biomarkers for diagnosing AD but also potentially specific pathways. The AD biomarkers proposed in this study could serve as indicators for prevention and diagnosis during physical examination.