miR-129-5p Ameliorates Ischemic Brain Injury by Binding to SIAH1 and Activating the mTOR Signaling Pathway

MicroRNA-based interventions in aberrant cell cycle diseases: Therapeutic strategies for cancers, central nervous system disorders and comorbidities

Malignant tumors and central nervous system (CNS) disorders are intricately linked to a process known as "aberrant cell cycle re-entry," which plays a critical role in the progression of these diseases. Addressing the dysregulation in cell cycles offers a promising therapeutic approach for cancers and CNS disorders. MicroRNAs (miRNAs) play a crucial role as regulators of gene expression in cell cycle transitions, presenting a promising therapeutic avenue for treating these disorders and their comorbidities. This review consolidates the progress made in the last three years regarding miRNA-based treatments for diseases associated with aberrant cell cycle re-entry. It encompasses exploring fundamental mechanisms and signaling pathways influenced by miRNAs in cancers and CNS disorders, particularly focusing on the therapeutic effects of exosome-derived miRNAs. The review also identifies specific miRNAs implicated in comorbidity of cancers and CNS disorders, discusses the future potential of miRNA reagents in managing cell cycle-related diseases.

Can exercise benefits be harnessed with drugs? A new way to combat neurodegenerative diseases by boosting neurogenesis

Adult hippocampal neurogenesis (AHN) is affected by multiple factors, such as enriched environment, exercise, ageing, and neurodegenerative disorders. Neurodegenerative disorders can impair AHN, leading to progressive neuronal loss and cognitive decline. Compelling evidence suggests that individuals engaged in regular exercise exhibit higher production of proteins that are essential for AHN and memory. Interestingly, specific molecules that mediate the effects of exercise have shown effectiveness in promoting AHN and cognition in different transgenic animal models. Despite these advancements, the precise mechanisms by which exercise mimetics induce AHN remain partially understood. Recently, some novel exercise molecules have been tested and the underlying mechanisms have been proposed, involving intercommunications between multiple organs such as muscle-brain crosstalk, liver-brain crosstalk, and gut-brain crosstalk. In this review, we will discuss the current evidence regarding the effects and potential mechanisms of exercise mimetics on AHN and cognition in various neurological disorders. Opportunities, challenges, and future directions in this research field are also discussed.

Crosstalk between ubiquitin ligases and ncRNAs drives cardiovascular disease progression

Cardiovascular diseases (CVDs) are multifactorial chronic diseases and have the highest rates of morbidity and mortality worldwide. The ubiquitin-proteasome system (UPS) plays a crucial role in posttranslational modification and quality control of proteins, maintaining intracellular homeostasis via degradation of misfolded, short-lived, or nonfunctional regulatory proteins. Noncoding RNAs (ncRNAs, such as microRNAs, long noncoding RNAs, circular RNAs and small interfering RNAs) serve as epigenetic factors and directly or indirectly participate in various physiological and pathological processes. NcRNAs that regulate ubiquitination or are regulated by the UPS are involved in the execution of target protein stability. The cross-linked relationship between the UPS, ncRNAs and CVDs has drawn researchers' attention. Herein, we provide an update on recent developments and perspectives on how the crosstalk of the UPS and ncRNAs affects the pathological mechanisms of CVDs, particularly myocardial ischemia/reperfusion injury, myocardial infarction, cardiomyopathy, heart failure, atherosclerosis, hypertension, and ischemic stroke. In addition, we further envision that RNA interference or ncRNA mimics or inhibitors targeting the UPS can potentially be used as therapeutic tools and strategies.

Mechanism of HDAC1 Regulating Iron Overload-Induced Neuronal Oxidative Damage After Cerebral Hemorrhage

Iron overload is associated with brain edema in the context of intracerebral hemorrhage (ICH). Here, we investigated the role of histone deacetylase 1 (HDAC1) in mediating oxidative damage induced by iron overload after ICH. Utilizing ICH mouse models and FeCl2-induced HT-22 cell models, we assessed HDAC1 expression and its impact on iron overload and oxidative damage. We examined the levels of Kruppel like factor 4 (KLF4), RAN binding protein 9 (RANBP9), as well as the acetylation levels of HDAC1 and histones H3 and H4 in the KLF4 promoter, and the KLF4 level in the RANBP9 promoter. Additionally, we investigated the binding relationships between KLF4 and the RANBP9 promoter, HDAC1 and miR-129-5p. Our results demonstrated elevated HDAC1 expression in ICH mice and FeCl2-induced HT-22 cells. HDAC1 silencing improved neurological function in mice, reduced brain edema, and alleviated iron overload and oxidative damage in vitro. HDAC1 downregulated KLF4 expression by reducing acetylation levels in the KLF4 promoter, leading to decreased KLF4 enrichment in the RANBP9 promoter and increased RANBP9 expression. Furthermore, upstream miR-129-5p inhibited HDAC1, and the downregulation of miR-129-5p mitigated the protective effect of HDAC1 silencing. Collectively, our findings highlight the significant role of HDAC1 in exacerbating iron overload-induced oxidative damage following ICH and its regulation by miR-129-5p.

Anti-apoptotic capacity of MALAT1 on hippocampal neurons correlates with CASP3 DNA methylation in a mouse model of autism

Prior evidence has suggested the alleviatory effect of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on neuroinflammation in neurodegenerative diseases. This study primarily investigates the underlying mechanism of how the long non-coding RNA MALAT1 affects neuronal apoptosis in the hippocampus of mice with autism spectrum disorder (ASD). The findings demonstrate that CASP3 is highly expressed while MALAT1 is downregulated in the hippocampal neurons of autistic mice. MALAT1 mainly localizes within the cell nucleus and recruits DNA methyltransferases (including DNMT1, DNMT3a, and DNMT3b) to the promoter region of CASP3, promoting its methylation and further inhibiting its expression. In vitro experiments reveal that reducing MALAT1 expression promotes the expression of CASP3 and Bax while suppressing Bcl-2 expression, thereby enhancing cellular apoptosis. Conversely, increasing MALAT1 expression yields the opposite effect. Consequently, these results further confirm the role of MALAT1 in suppressing neuronal apoptosis in the hippocampus of mice with ASD through the regulation of CASP3 promoter methylation. Thus, this research unveils the significant roles of MALAT1 and CASP3 in the pathogenesis of ASD, offering new possibilities for future therapeutic interventions.

Discerning the Prospects of miRNAs as a Multi-Target Therapeutic and Diagnostic for Alzheimer's Disease

Although over the last few decades, numerous attempts have been made to halt Alzheimer's disease (AD) progression and mitigate its symptoms, only a few have been proven beneficial. Most medications available, still only cater to the symptoms of the disease rather than fixing the cause at the root level. A novel approach involving the use of miRNAs, which work on the principle of gene silencing, is being explored by scientists. Naturally present miRNAs in the biological system help to regulate various genes than may be implicated in AD-like BACE-1 and APP. One miRNA thus, holds the power to keep a check on several genes, conferring it the ability to be used as a multi-target therapeutic. With aging and the onset of diseased pathology, dysregulation of these miRNAs is observed. This flawed miRNA expression is responsible for the unusual buildup of amyloid proteins, fibrillation of tau proteins in the brain, neuronal death and other hallmarks leading to AD. The use of miRNA mimics and miRNA inhibitors provides an attractive perspective for fixing the upregulation and downregulation of miRNAs that led to abnormal cellular activities. Furthermore, the detection of miRNAs in the CSF and serum of diseased patients might be considered an earlier biomarker for the disease. While most of the therapies designed around AD have not succeeded completely, the targeting of dysregulated miRNAs in AD patients might give a new direction to scholars to develop an effective treatment for Alzheimer's disease.

MicroRNA-193b-3p reduces oxidative stress and mitochondrial damage in rats with cerebral ischemia-reperfusion injury via the seven in absentia homolog 1/Jun N-terminal kinase pathway

Ischemic stroke is one of the major causes of death and disability among adults. This study sought to explore the mechanism of microRNA (miR)-193b-3p in rats with cerebral ischemia-reperfusion (I/R) injury. The cerebral I/R injury models of rats were established using the suture-occluded method. The pathological changes were observed, and oxidative stress (OS) and mitochondrial function indexes in rat brain tissue were examined. The levels of miR-193b-3p and seven in absentia homolog 1 (SIAH1) were detected. miR-193b-3p agomir or antagomir was injected into the lateral ventricle of I/R rats to overexpress or inhibit miR-193b-3p expression. The targeting relationship between miR-193b-3p and SIAH1 was verified. The effect of SIAH1 overexpression on brain injury in I/R rats was investigated by injecting the lentivirus vector into the lateral ventricle. The phosphorylation level of Jun N-terminal kinase (JNK) was identified. miR-193b-3p was lowly expressed in I/R rats. Overexpression of miR-193b-3p alleviated the pathological damage of I/R rats and limited the OS and mitochondrial damage. miR-193b-3p targeted SIAH1. Overexpression of SIAH1 partially reversed the protection of miR-193b-3p overexpression against cerebral I/R injury. p-JNK was up-regulated in I/R rats and overexpression of miR-193b-3p inhibited p-JNK. Overall, overexpression of miR-193b-3p targeted SIAH1 to inhibit the activation of the JNK pathway and protect rats against cerebral I/R injury.

Dysregulation of mTOR Signaling after Brain Ischemia

In this review, we provide recent data on the role of mTOR kinase in the brain under physiological conditions and after damage, with a particular focus on cerebral ischemia. We cover the upstream and downstream pathways that regulate the activation state of mTOR complexes. Furthermore, we summarize recent advances in our understanding of mTORC1 and mTORC2 status in ischemia–hypoxia at tissue and cellular levels and analyze the existing evidence related to two types of neural cells, namely glia and neurons. Finally, we discuss the potential use of mTORC1 and mTORC2 as therapeutic targets after stroke.

Long Non-coding RNA Peg13 Alleviates Hypoxic-Ischemic Brain Damage in Neonatal Mice via miR-20a-5p/XIAP Axis

Long noncoding RNA (LncRNA) Peg13 has been demonstrated to protect against neurological diseases. However, its underlying mechanism in the progression of hypoxic-ischemic brain damage (HIBD) has not been well investigated. The expression of target genes was determined in neonatal mice with HIBD and in mouse hippocampal neurons during oxygen-glucose deprivation (OGD) using quantitative real-time PCR (qRT-PCR) and immunoblotting. Functional assays, including CCK-8 cell viability and apoptotic cell detection using TdT mediated dUTP nick ending labeling (TUNEL) assay were used to examine the neuroprotective role of Peg13 in mouse hippocampal neurons. Luciferase assays were performed to determine the regulatory mechanism of Peg13 in OGD-induced neuronal apoptosis. Peg13 was reduced in HIBD mice and OGD-treated mouse hippocampal neurons. Altered Peg13 expression relieved OGD-induced neuronal apoptosis. Mechanistically, Peg13 may serve as a sponge for miR-20a-5p to increase the expression of X chromosome-linked inhibitor of apoptosis (XIAP), a downstream target of miR-20a-5p. Our study showed that Peg13 fulfilled its anti-apoptotic function in neurons through suppressing XIAP expression by sponging miR-20a-5p. Together, Peg13 binds to miR-20a-5p to upregulate XIAP and alleviate HIBD in neonatal mice. The Peg13/miR-20a-5p/XIAP competing endogenous RNA (ceRNA) axis could be a potential therapeutic target for HIBD.