Melatonin protects against Aβ-induced neurotoxicity in primary neurons via miR-132/PTEN/AKT/FOXO3a pathway

Extracellular vesicle-packed microRNAs profiling in Alzheimer's disease: The molecular intermediary between pathology and diagnosis

MicroRNAs (miRNAs), referring to a type of non-coding RNAs functioning in various biological processes, participate in the pathophysiology of Alzheimer's disease (AD) through increasing amyloid-beta (Aβ) production, enhancing Tau phosphorylation, and inducing neuroinflammation. Meanwhile, extracellular vesicles (EVs) have been suggested as promising carriers of AD biomarkers as they possess the ability to transmit information from cerebral tissue to peripheral blood. Inspired by the above findings, we in this review systematically generalized the roles of miRNAs in AD and explored the potential of EV-packed miRNA as biomarkers for early diagnosis of AD. Through the detailed investigation, this review may highlight the promise of EV-packed miRNAs in advancing our understanding of AD, and underscore the imperative needs of further studies on their diagnostic potential.

Protective Activity of Melatonin Combinations and Melatonin-Based Hybrid Molecules in Neurodegenerative Diseases

The identification of protective agents for the treatment of neurodegenerative diseases is the mainstay therapeutic goal to modify the disease course and arrest the irreversible disability progression. Pharmacological therapies synergistically targeting multiple pathogenic pathways, including oxidative stress, mitochondrial dysfunction, and inflammation, are prime candidates for neuroprotection. Combination or synergistic therapy with melatonin, whose decline correlates with altered sleep/wake cycle and impaired glymphatic "waste clearance" system in neurodegenerative diseases, has a great therapeutic potential to treat inflammatory neurodegenerative states. Despite the protective outcomes observed in preclinical studies, mild or poor outcomes were observed in clinical settings, suggesting that melatonin combinations promoting synergistic actions at appropriate doses might be more suitable to treat multifactorial neurodegenerative disorders. In this review, we first summarize the key melatonin actions and pathways contributing to cell protection and its therapeutic implication in Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). We remark the major controversies in the field, mostly generated by the lack of a common consensus for the optimal dosing, molecular targets, and toxicity. Then, we review the literature investigating the efficacy of melatonin combinations with approved or investigational neuroprotective agents and of melatonin-containing hybrid molecules, both in vitro and in animal models of AD, PD, and MS, as well as the efficacy of add-on melatonin in clinical settings. We highlight the rationale for such melatonin combinations with a focus on the comparison with single-agent treatment and on the assays in which an additive or a synergistic effect has been achieved. We conclude that a better characterization of the mechanisms underlying such melatonin synergistic actions under neuroinflammation at appropriate doses needs to be tackled to advance successful clinical translation of neuroprotective melatonin combination therapies or melatonin-based hybrid molecules.

A Comprehensive Review of Membrane Transporters and MicroRNA Regulation in Alzheimer's Disease

Alzheimer's disease (AD) is a distressing neurodegenerative condition characterized by the accumulation of amyloid-beta (Aβ) plaques and tau tangles within the brain. The interconnectedness between membrane transporters (SLCs) and microRNAs (miRNAs) in AD pathogenesis has gained increasing attention. This review explores the localization, substrates, and functions of SLC transporters in the brain, emphasizing the roles of transporters for glutamate, glucose, nucleosides, and other essential compounds. The examination delves into the significance of SLCs in AD, their potential for drug development, and the intricate realm of miRNAs, encompassing their transcription, processing, functions, and regulation. MiRNAs have emerged as significant players in AD, including those associated with mitochondria and synapses. Furthermore, this review discusses the intriguing nexus of miRNAs targeting SLC transporters and their potential as therapeutic targets in AD. Finally, the review underscores the interaction between SLC transporters and miRNA regulation within the context of Alzheimer's disease, underscoring the need for further research in this area. This comprehensive review aims to shed light on the complex mechanisms underlying the causation of AD and provides insights into potential therapeutic approaches.

Inflammatory signaling pathways in Alzheimer's disease: Mechanistic insights and possible therapeutic interventions

The complex pathophysiology of Alzheimer's disease (AD) poses challenges for the development of therapies. Recently, neuroinflammation has been identified as a key pathogenic mechanism underlying AD, while inflammation has emerged as a possible target for the management and prevention of AD. Several prior studies have demonstrated that medications modulating neuroinflammation might lessen AD symptoms, mostly by controlling neuroinflammatory signaling pathways such as the NF-κB, MAPK, NLRP3, etc, and their respective signaling cascade. Moreover, targeting these inflammatory modalities with inhibitors, natural products, and metabolites has been the subject of intensive research because of their anti-inflammatory characteristics, with many studies demonstrating noteworthy pharmacological capabilities and potential clinical applications. Therefore, targeting inflammation is considered a promising strategy for treating AD. This review comprehensively elucidates the neuroinflammatory mechanisms underlying AD progression and the beneficial effects of inhibitors, natural products, and metabolites in AD treatment.

The role of Foxo3a in neuron-mediated cognitive impairment

Cognitive impairment (COI) is a prevalent complication across a spectrum of brain disorders, underpinned by intricate mechanisms yet to be fully elucidated. Neurons, the principal cell population of the nervous system, orchestrate cognitive processes and govern cognitive balance. Extensive inquiry has spotlighted the involvement of Foxo3a in COI. The regulatory cascade of Foxo3a transactivation implicates multiple downstream signaling pathways encompassing mitochondrial function, oxidative stress, autophagy, and apoptosis, collectively affecting neuronal activity. Notably, the expression and activity profile of neuronal Foxo3a are subject to modulation via various modalities, including methylation of promoter, phosphorylation and acetylation of protein. Furthermore, upstream pathways such as PI3K/AKT, the SIRT family, and diverse micro-RNAs intricately interface with Foxo3a, engendering alterations in neuronal function. Through several downstream routes, Foxo3a regulates neuronal dynamics, thereby modulating the onset or amelioration of COI in Alzheimer's disease, stroke, ischemic brain injury, Parkinson's disease, and traumatic brain injury. Foxo3a is a potential therapeutic cognitive target, and clinical drugs or multiple small molecules have been preliminarily shown to have cognitive-enhancing effects that indirectly affect Foxo3a. Particularly noteworthy are multiple randomized, controlled, placebo clinical trials illustrating the significant cognitive enhancement achievable through autophagy modulation. Here, we discussed the role of Foxo3a in neuron-mediated COI and common cognitively impaired diseases.

Extracellular Vesicles: A New Approach to Study the Brain's Neural System and Its Diseases

In normal and pathophysiological conditions our cells secrete vesicular bodies known as extracellular particles. Extracellular vesicles are lipid-bound extracellular particles. A majority of these extracellular vesicles are linked to cell-to-cell communication. Brain consists of tightly packed neural cells. Neural cell releases extracellular vesicles in cerebrospinal fluid. Extracellular vesicle mediated crosstalk maintains neural homeostasis in the central nervous system via transferring cargos between neural cells. In neurodegenerative diseases, small extracellular vesicle transfer misfolded proteins to healthy cells in the neural microenvironment. They can also cross blood-brain barrier (BBB) and stimulate peripheral immune response inside central nervous system. In today's world different approaches employ extracellular vesicle in various therapeutics. This review gives a brief knowledge about the biological relevance of extracellular vesicles in the central nervous system and relevant advances in the translational application of EV in brain disorders.

Bridging neurotrophic factors and bioactive peptides to Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder. As the demographic shifting towards an aging population, AD has emerged as a prominent public health concern. The pathogenesis of AD is complex, and there are no effective treatment methods for AD until now. In recent years, neurotrophic factors and bioactive peptides including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), irisin, melatonin, have been discovered to exert neuroprotective functions for AD. Bioactive peptides can be divided into two categories based on their sources: endogenous and exogenous. This review briefly elaborates on the pathogenesis of AD and analyzes the regulatory effects of endogenous and exogenous peptides on the pathogenesis of AD, thereby providing new therapeutic targets for AD and a theoretical basis for the application of bioactive peptides as adjunctive therapies for AD.

Understanding the multifaceted role of miRNAs in Alzheimer's disease pathology

Small non-coding RNAs (miRNAs) regulate gene expression by binding to mRNA and mediating its degradation or inhibiting translation. Since miRNAs can regulate the expression of several genes, they have multiple roles to play in biological processes and human diseases. The majority of miRNAs are known to be expressed in the brain and are involved in synaptic functions, thus marking their presence and role in major neurodegenerative disorders, including Alzheimer's disease (AD). In AD, amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) are known to be the major hallmarks. The clearance of Aβ and tau is known to be associated with miRNA dysregulation. In addition, the β-site APP cleaving enzyme (BACE 1), which cleaves APP to form Aβ, is also found to be regulated by miRNAs, thus directly affecting Aβ accumulation. Growing evidences suggest that neuroinflammation can be an initial event in AD pathology, and miRNAs have been linked with the regulation of neuroinflammation. Inflammatory disorders have also been associated with AD pathology, and exosomes associated with miRNAs are known to regulate brain inflammation, suggesting for the role of systemic miRNAs in AD pathology. Several miRNAs have been related in AD, years before the clinical symptoms appear, most of which are associated with regulating the cell cycle, immune system, stress responses, cellular senescence, nerve growth factor (NGF) signaling, and synaptic regulation. Phytochemicals, especially polyphenols, alter the expression of various miRNAs by binding to miRNAs or binding to the transcriptional activators of miRNAs, thus control/alter various metabolic pathways. Awing to the sundry biological processes being regulated by miRNAs in the brain and regulation of expression of miRNAs via phytochemicals, miRNAs and the regulatory bioactive phytochemicals can serve as therapeutic agents in the treatment and management of AD.

A novel approach to type 3 diabetes mechanism: The interplay between noncoding RNAs and insulin signaling pathway in Alzheimer's disease

Today, growing evidence indicates that patients with type 2 diabetes (T2D) are at a higher risk of developing Alzheimer's disease (AD). Indeed, AD as one of the main causes of dementia in people aged more than 65 years can be aggravated by insulin resistance (IR) and other metabolic risk factors related to T2D which are also linked to the function of the brain. Remarkably, a new term called "type 3 diabetes" has been suggested for those people who are diagnosed with AD while also showing the symptoms of IR and T2D. In this regard, the role of genetic and epigenetic changes associated with AD has been confirmed by many studies. On the other hand, it should be noted that the insulin signaling pathway is highly regulated by various mechanisms, including epigenetic factors. Among these, the role of noncoding RNAs (ncRNAs), including microRNAs and long noncoding RNAs has been comprehensively studied with respect to the pathology of AD and the most well-known underlying mechanisms. Nevertheless, the number of studies exploring the association between ncRNAs and the downstream targets of the insulin signaling pathway in the development of AD has notably increased in recent years. With this in view, the present study aimed to review the interplay between different ncRNAs and the insulin signaling pathway targets in the pathogenesis of AD to find a new approach in the field of combining biomarkers or therapeutic targets for this disease.

Melatonin ameliorates tau-related pathology via the miR-504-3p and CDK5 axis in Alzheimer’s disease

Background

Intracellular accumulation of the microtubule-associated protein tau and its hyperphosphorylated forms is a key neuropathological feature of Alzheimer’s disease (AD). Melatonin has been shown to prevent tau hyperphosphorylation in cellular and animal models. However, the molecular mechanisms by which melatonin attenuates tau hyperphosphorylation and tau-related pathologies are not fully understood.

Methods

Immunofluorescence, immunoblotting analysis and thioflavin-S staining were employed to examine the effects of early and late treatment of melatonin on tau-related pathology in hTau mice, in which nonmutated human tau is overexpressed on a mouse tau knockout background. High-throughput microRNA (miRNA) sequencing, quantitative RT-PCR, luciferase reporter assay and immunoblotting analysis were performed to determine the molecular mechanism.

Results

We found that both early and late treatment of melatonin efficiently decreased the phosphorylation of soluble and insoluble tau at sites related to AD. Moreover, melatonin significantly reduced the number of neurofibrillary tangles (NFTs) and attenuated neuronal loss in the cortex and hippocampus. Furthermore, using miRNA microarray analysis, we found that miR-504-3p expression was upregulated by melatonin in the hTau mice. The administration of miR-504-3p mimics dramatically decreased tau phosphorylation by targeting p39, an activator of the well-known tau kinase cyclin-dependent kinase 5 (CDK5). Compared with miR-504-3p mimics alone, co-treatment with miR-504-3p mimics and p39 failed to reduce tau hyperphosphorylation.

Conclusions

Our results suggest for the first time that melatonin alleviates tau-related pathologies through upregulation of miR-504-3p expression by targeting the p39/CDK5 axis and provide novel insights into AD treatment strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40035-022-00302-4.

The Role of miR-20 in Health and Disease of the Central Nervous System

Current understanding of the mechanisms underlying central nervous system (CNS) injury is limited, and traditional therapeutic methods lack a molecular approach either to prevent acute phase or secondary damage, or to support restorative mechanisms in the nervous tissue. microRNAs (miRNAs) are endogenous, non-coding RNA molecules that have recently been discovered as fundamental and post-transcriptional regulators of gene expression. The capacity of microRNAs to regulate the cell state and function through post-transcriptionally silencing hundreds of genes are being acknowledged as an important factor in the pathophysiology of both acute and chronic CNS injuries. In this study, we have summarized the knowledge concerning the pathophysiology of several neurological disorders, and the role of most canonical miRNAs in their development. We have focused on the miR-20, the miR-17~92 family to which miR-20 belongs, and their function in the normal development and disease of the CNS.

Role of melatonin in Alzheimer's disease: From preclinical studies to novel melatonin-based therapies

Melatonin and novel melatonin-based therapies such as melatonin-containing hybrid molecules, melatonin analogues, and melatonin derivatives have been investigated as potential therapeutics against Alzheimer's disease (AD) pathogenesis. In this review, we examine the developmental trends of melatonin therapies for AD from 1997 to 2021. We then highlight the neuroprotective mechanisms of melatonin therapy derived from preclinical studies. These mechanisms include the alleviation of amyloid-related burden, neurofibrillary tangle accumulation, oxidative stress, neuroinflammation, apoptosis, mitochondrial dysfunction, and impaired neuroplasticity and neurotransmission. We further illustrate the beneficial effects of melatonin on behavior in animal models of AD. Next, we discuss the clinical effects of melatonin on sleep, cognition, behavior, psychiatric symptoms, electroencephalography findings, and molecular biomarkers in patients with mild cognitive impairment and AD. We then explore the effectiveness of novel melatonin-based therapies. Lastly, we discuss the limitations of current melatonin therapies for AD and suggest two emerging research themes for future study.

MicroRNA-132 is overexpressed in fetuses with late-onset fetal growth restriction

Background and Aims

To evaluate the expression of microRNA 132 (miR-132) in fetuses with normal growth and in fetuses with late-onset growth restriction (FGR).

Methods

In a prospective cohort study, 48 fetuses (24 with late-onset FGR and 24 with normal growth) were scanned with Doppler ultrasound after 34 weeks to measure the umbilical artery and middle cerebral artery pulsatility indices and followed until birth. Subsequently, blood samples from the umbilical cord were collected to evaluate the expression of miR-132 by means of Real-time quantitative polymerase chain reaction, determining the existence of normality cut-offs and associations with birth weight (BW) centile, cerebroplacental ratio multiples of the median (CPR MoM), and intrapartum fetal compromise (IFC).

Results

In comparison with normal fetuses, late-onset FGR fetuses showed upregulation of miR-132 (33.94 ± 45.04 vs. 2.88 ± 9.32 2-ddC t, p < 0.001). Using 5 as a cut-off we obtained a sensitivity of 50% and a specificity of 96% for the diagnosis of FGR, while for IFC these values were respectively 27% and 73%. Expression of miR-132 was associated with BW centile but not with CPR MoM. Finally, the best detection of IFC was achieved combining miR-132 expression and CPR MoM (AUC = 0.69, p < 0.05).

Conclusion

Fetuses with late-onset FGR show upregulation of miR-132. Further studies are needed to investigate the role of miR-132 in the management of late-onset FGR.

Antitumor and Protective Effects of Melatonin: The Potential Roles of MicroRNAs

MicroRNAs (miRNAs) are endogenous short noncoding RNAs with approximately 22 nucleotides. The primary function of miRNAs is the negative regulation of target gene expression via mRNA degradation or translation inhibition. During recent years, much attention has been made toward miRNAs' role in different disorders; particularly cancer and compounds with modulatory effects on miRNAs are of interest. Melatonin is one of these compounds which is secreted by the pineal gland. Also, melatonin is present in the leaves, fruits, and seeds of plants. Melatonin has several valuable biological activities such as antioxidant, anti-inflammation, antitumor, and antiaging activities. This important agent is extensively used to treat different disorders such as cancer and neurodegenerative and cardiovascular diseases. This review aims to describe the modulatory effect of melatonin on miRNAs as novel targets.

Melatonin protects H9c2 cardiomyoblasts from oxygen-glucose deprivation and reperfusion-induced injury by inhibiting Rac1/JNK/Foxo3a/Bim signaling pathway

Melatonin has been shown to protect against ischemia/reperfusion (I/R)-induced myocardial injury, however, the precise molecular mechanisms have not been fully clarified. The present study was aimed to investigate whether inactivation of Rac1/JNK/Foxo3a/Bim signaling pathway is responsible for the protective effect of melatonin on I/R-induced myocardial injury. Our results showed that Foxo3a downregulation contributed to the protective effect of melatonin on OGD/R-induced injury of H9c2 cardiomyoblasts. Melatonin treatment led to a reduced activity of Rac1, which was responsible for Foxo3a downregulation and decreased cell injury in OGD/R-exposed H9c2 cells. Furthermore, JNK acts as a downstream effector of Rac1 in mediating melatonin-induced inactivation of Foxo3a/Bim signaling pathway and decreased cell injury in OGD/R-exposed H9c2 cells. In conclusion, our results indicate that melatonin protects H9c2 cells against OGD/R-induced injury by inactivating the Rac1/JNK/Foxo3a/Bim signaling pathway. This study provided a novel insight into the protective mechanism of melatonin against I/R-induced myocardial injury.

The PI3K/Akt signaling axis in Alzheimer's disease: a valuable target to stimulate or suppress?

Among the long list of age-related complications, Alzheimer's disease (AD) has the most dreadful impact on the quality of life due to its devastating effects on memory and cognitive abilities. Although a plausible correlation between the phosphatidylinositol 3-kinase (PI3K) signaling and different processes involved in neurodegeneration has been evidenced, few articles reviewed the task. The current review aims to unravel the mechanisms by which the PI3K pathway plays pro-survival roles in normal conditions, and also to discuss the original data obtained from international research laboratories on this topic. Responses to questions on how alterations of the PI3K/Akt signaling pathway affect Tau phosphorylation and the amyloid cascade are given. In addition, we provide a general overview of the association between oxidative stress, neuroinflammation, alterations of insulin signaling, and altered autophagy with aberrant activation of this axis in the AD brain. The last section provides a special focus on the therapeutic possibility of the PI3K/Akt/mTOR modulators, either categorized as chemicals or herbals, in AD. In conclusion, determining the correct timing for the administration of the drugs seems to be one of the most important factors in the success of these agents. Also, the role of the PI3K/Akt signaling axis in the progression or repression of AD widely depends on the context of the cells; generally speaking, while PI3K/Akt activation in neurons and neural stem cells is favorable, its activation in microglia cells may be harmful.

Up-regulated microRNA-132 reduces the cognition-damaging effect of sevoflurane on Alzheimer's disease rats by inhibiting FOXA1

OBJECTIVE

Some studies have implied the damaging effect of sevoflurane (sevo) on cognitive function in Alzheimer's disease (AD). This research was conducted to explore the effect of microRNA (miR)-132/forkhead-box A1 (FOXA1) axis on cognitive ability of sevo-treated AD rats.

METHODS

The condensed-matter Aβ_1-40-induced AD rats were injected with miR-132- or FOXA1-related plasmids, followed by inhalation with 3% sevo. Then, the cognitive functions of AD rats were assessed. miR-132 and FOXA1 levels in hippocampal tissues of AD rats, and their interaction were identified.

RESULTS

miR-132 expression was reduced and FOXA1 mRNA and protein levels were elevated in AD rats. miR-132 targeted FOXA1. Sevo treatment impaired cognitive function in AD rats. Elevated miR-132 or inhibited FOXA1 attenuated sevo-mediated injury in AD rats. Overexpressed FOXA1 rescued the effect of elevated miR-132 in AD rats with sevo treatment.

CONCLUSION

Up-regulated miR-132 reduces the cognition-damaging effect of sevo on AD rats by inhibiting FOXA1.

SIRT2 and FOXO3a expressions in the cerebral cortex and hippocampus of young and aged male rats: antioxidant and anti-apoptotic effects of melatonin

Melatonin has antioxidant, anti-apoptotic and anti-aging effects in the brain. Sirtuin2 (SIRT2) accumulates in the central nervous system with aging, and its inhibition appears to be protective in aging and aging-related neurodegenerative diseases. Forkhead Box-class O3a (FOXO3a) transcription factor is one of the main targets of SIRT2, and SIRT2-mediated FOXO3a deacetylation is closely related to aging, oxidative stress, and apoptosis. This study aimed to investigate the effects of melatonin on SIRT2 and FOXO3a expressions in the cerebral cortex and hippocampus of aged rats. Young (3 months, n = 18) and aged (22 months, n = 18) male Wistar rats were divided into control (4% DMSO-PBS, sc, for 21 days), melatonin (10 mg/kg, sc, for 21 days) and salermide (1 mM; 25 μl/100 g bw, ip, for 21 days) groups. SIRT2, FOXO3a, Bcl-2, Bax and Bim expressions in the cerebral cortex and hippocampus were demonstrated by Western blotting. SIRT2 and FOXO3a protein levels were also measured by a sandwich ELISA method. Oxidative stress index (OSI) was calculated by measuring total oxidant status (TOS) and total antioxidant status (TAS). Aging increased SIRT2, FOXO3a, Bim (only in the cerebral cortex), Bax (only in the hippocampus), TOS, and OSI, while decreasing Bcl-2, Bcl-2/Bax and TAS in both brain regions. Melatonin decreased SIRT2, FOXO3a, oxidative stress parameters and pro-apoptotic proteins, while increasing TAS, Bcl-2 and Bcl-2/Bax, more specifically in the hippocampus of the aged brain. Our results indicate that inhibition of SIRT2 and FOXO3a expressions appears to be involved in the protective effects of melatonin in the hippocampus of aged rats.

Melatonin restores osteoporosis-impaired osteogenic potential of bone marrow mesenchymal stem cells and alleviates bone loss through the HGF/PTEN/Wnt/β-catenin axis

Background:

Previous studies reported that melatonin exerts its effect on mesenchymal stem cell (MSC) survival and differentiation into osteogenic and adipogenic lineage. In the current study we aimed to explore the effect of melatonin on osteoporosis and relevant mechanisms.

Methods:

Real-time qualitative polymerase chain reaction (RT-qPCR) and Western blot analysis were conducted to determine expression of HGF, PTEN, and osteoblast differentiation-related genes in ovariectomy (OVX)-induced osteoporosis mice and the isolated bone marrow MSCs (BMSCs). Pre-conditioning with melatonin (1 μmol/l, 10 μmol/l and 100 μmol/l) was carried out in OVX mice BMSCs. Bone microstructure was analyzed using micro-computed tomography and the contents of alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase 5b (TRAP5b) were detected by enzyme-linked immunosorbent assay in serum. BMSC proliferation was measured by cell-counting kit (CCK)-8 assay. Alizarin red S (ARS) staining and ALP activity assay were performed to assess BMSC mineralization and calcification. The activity of the Wnt/β-catenin pathway was evaluated by dual-luciferase reporter assay.

Results:

Melatonin prevented bone loss in OVX mice. Melatonin increased ALP expression and reduced TRAP5b expression. HGF and β-catenin were downregulated, while PTEN was upregulated in the femur of OVX mice. Melatonin elevated HGF expression and then stimulated BMSC proliferation and osteogenic differentiation. Additionally, HGF diminished the expression of PTEN, resulting in activated Wnt/β-catenin pathway both in vitro and in vivo. Furthermore, melatonin was shown to ameliorate osteoporosis in OVX mice via the HGF/PTEN/Wnt/β-catenin axis.

Conclusion:

Melatonin could potentially enhance osteogenic differentiation of BMSCs and retard bone loss through the HGF/PTEN/Wnt/β-catenin axis.

Melatonin as a promising modulator of aging related neurodegenerative disorders: Role of microRNAs

One of the host risk factors involved in aging-related diseases is coupled with the reduction of endogenous melatonin (MLT) synthesis in the pineal gland. MLT is considered a well-known pleiotropic regulatory hormone to modulate a multitude of biological processes such as the regulation of circadian rhythm attended by potent anti-oxidant, anti-inflammatory, and anti-cancer properties. It has also been established that the microRNAs family, as non-coding mRNAs regulating post-transcriptional processes, also serve a crucial role to promote MLT-related advantageous effects in both experimental and clinical settings. Moreover, the anti-aging impact of MLT and miRNAs participation jointly are of particular interest, recently. In this review, we aimed to scrutinize recent advances concerning the therapeutic implications of MLT, particularly in the brain tissue in the face of aging. We also assessed the possible interplay between microRNAs and MLT, which could be considered a therapeutic strategy to slow down the aging process in the nervous system.

FOXO and related transcription factors binding elements in the regulation of neurodegenerative disorders

Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and others, are characterized by progressive loss of neuronal cells, which causes memory impairment and cognitive decline. Mounting evidence demonstrated the possible implications of diverse biological processes, namely oxidative stress, mitochondrial dysfunction, aberrant cell cycle re-entry, post-translational modifications, protein aggregation, impaired proteasome dysfunction, autophagy, and many others that cause neuronal cell death. The condition worsens as there is no effective treatment for such diseases due to their complex pathogenesis and mechanism. Mounting evidence demonstrated the role of regulatory transcription factors, such as NFκβ, FoxO, Myc, CREB, and others that regulate the biological processes and diminish the disease progression and pathogenesis. Studies demonstrated that forkhead box O (FoxO) transcription factors had been implicated in the regulation of aging and longevity. Further, the functions of FoxO proteins are regulated by different post-translational modifications (PTMs), namely acetylation, and ubiquitination. Various studies concluded that FoxO proteins exert both neuroprotective and neurotoxic properties depending on their regulation mechanism and activity in the brain. Thus, understanding the nature of FoxO expression and activity in the brain will help develop effective therapeutic strategies. Herein, firstly, we discuss the role of FoxO protein in cell cycle regulation and cell proliferation, followed by the regulation of FoxO proteins through acetylation and ubiquitination. We also briefly explain the activity and expression pattern of FoxO proteins in the neuronal cells and explain the mechanism through which FoxO proteins are rescued from oxidative stress-induced neurotoxicity. Later on, we present a detailed view of the implication of FoxO proteins in neurodegenerative disease and FoxO proteins as an effective therapeutic target.

SRY-Box 21 Antisense RNA 1 Knockdown Diminishes Amyloid Beta25-35-Induced Neuronal Damage by miR-132/PI3K/AKT Pathway

Our study aimed to explore the function and mechanism of action of long noncoding RNA (lncRNA) SRY-Box 21 antisense RNA 1 (SOX21-AS1) in amyloid beta_25-35 (Aβ_25-35)-induced neuronal damage. To induce neuronal damage, neuronal cells and differentiated IMR-32 neuroblastoma cells were challenged by Aβ_25-35. SOX21-AS1 and miR-132 quantities were detected by quantitative reverse transcription polymerase chain reaction. Cell damage was evaluated by detecting the changes of cell viability, apoptosis, and oxidative stress. Cell viability was measured using cell counting kit-8. Cell apoptosis was evaluated by flow cytometry and caspase-3 activity. The oxidative stress was analyzed by reactive oxygen species level. The expression of proteins associated with the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway was examined by western blot. SOX21-AS1 abundance was up-regulated in Aβ_25-35-challenged neuronal cells. Silencing of SOX21-AS1 attenuated Aβ_25-35-induced viability reduction and promotion of apoptosis and oxidative stress, suggesting that silencing of SOX21-AS1 repressed Aβ_25-35-induced neuronal damage. miR-132 quantity was reduced in Aβ_25-35-challenged neuronal cells, and negatively controlled by SOX21-AS1. miR-132 knockdown abolished the effect of SOX21-AS1 silencing on Aβ_25-35-induced neuronal damage, indicating that SOX21-AS1 controls Aβ_25-35-induced neuronal damage via regulating miR-132. The PI3K/AKT signaling was repressed in Aβ_25-35-challenged cells, but this effect was counteracted upon overexpression of miR-132. In conclusion, SOX21-AS1 knockdown mitigated Aβ_25-35-dependent neuronal cell damage by promoting miR-132/PI3K/AKT pathway.

Melatonin and Melatonergic Influence on Neuronal Transcription Factors: Implications for the Development of Novel Therapies for Neurodegenerative Disorders

Melatonin is a multifunctional signalling molecule that is secreted by the mammalian pineal gland, and also found in a number of organisms including plants and bacteria. Research has continued to uncover an ever-increasing number of processes in which melatonin is known to play crucial roles in mammals. Amongst these functions is its contribution to cell multiplication, differentiation and survival in the brain. Experimental studies show that melatonin can achieve these functions by influencing transcription factors which control neuronal and glial gene expression. Since neuronal survival and differentiation are processes that are important determinants of the pathogenesis, course and outcome of neurodegenerative disorders; the known and potential influences of melatonin on neuronal and glial transcription factors are worthy of constant examination. In this review, relevant scientific literature on the role of melatonin in preventing or altering the course and outcome of neurodegenerative disorders, by focusing on melatonin's influence on transcription factors is examined. A number of transcription factors whose functions can be influenced by melatonin in neurodegenerative disease models have also been highlighted. Finally, the therapeutic implications of melatonin's influences have also been discussed and the potential limitations to its applications have been highlighted.

Syringin Prevents Aβ25-35-Induced Neurotoxicity in SK-N-SH and SK-N-BE Cells by Modulating miR-124-3p/BID Pathway

Alzheimer's disease (AD) is a neurodegenerative disorder disease, disturbing people's normal life. Syringin was mentioned to antagonize Amyloid-β (Aβ)-induced neurotoxicity. However, the action mechanism is still not fully elucidated. This study aimed to explore a molecular mechanism of syringin in defending Aβ-induced neurotoxicity. SK-N-SH and SK-N-BE cells were treated with amyloid β-protein fragment 25-35 (Aβ_25-35) to induce cell neurotoxicity. The injury effects were distinguished by assessing cell viability and cell apoptosis using cell counting kit-8 (CCK-8) assay and flow cytometry assay, respectively. The expression of Cleaved-caspase3 (Cleaved-casp3), B cell lymphoma/leukemia-2 (Bcl-2), Bcl-2 associated X protein (Bax) and BH3 interacting domain death agonist (BID) at the protein level was determined by western blot. The expression of miR-124-3p and BID was detected using quantitative real-time polymerase chain reaction (qRT-PCR). The interaction between miR-124-3p and BID was predicted by the online database starBase and confirmed by dual-luciferase reporter assay plus RNA pull-down assay. Aβ_25-35 treatment inhibited cell viability and induced cell apoptosis, while the addition of syringin recovered cell viability and suppressed cell apoptosis. MiR-124-3p was significantly downregulated in Aβ_25-35-treated SK-N-SH and SK-N-BE cells, and BID was upregulated. Nevertheless, the addition of syringin reversed their expression. BID was a target of miR-124-3p, and its downregulation partly prevented Aβ_25-35-induced injuries. Syringin protected against Aβ_25-35-induced neurotoxicity by enhancing miR-124-3p expression and weakening BID expression, and syringin strengthened the expression of miR-124-3p to diminish BID level. Syringin ameliorated Aβ_25-35-induced neurotoxicity in SK-N-SH and SK-N-BE cells by regulating miR-124-3p/BID pathway, which could be a novel theoretical basis for syringin to treat AD.

The Effect of Melatonin Modulation of Non-coding RNAs on Central Nervous System Disorders: An Updated Review

Melatonin is a hormone produced in and secreted by the pineal gland. Besides its role in regulating circadian rhythms, melatonin has a wide range of protective functions in the central nervous system (CNS) disorders. The mechanisms underlying this protective function are associated with the regulatory effects of melatonin on related genes and proteins. In addition to messenger ribonucleic acid (RNA) that can be translated into protein, an increasing number of non-coding RNAs in the human body are proven to participate in many diseases. This review discusses the current progress of research on the effects of melatonin modulation of non-coding RNAs (ncRNAs), including microRNA, long ncRNA, and circular RNA. The role of melatonin in regulating common pathological mechanisms through these ncRNAs is also summarized. Furthermore, the ncRNAs, currently shown to be involved in melatonin signaling in CNS diseases, are discussed. The information compiled in this review will open new avenues for future research into melatonin mechanisms and provide a further understanding of ncRNAs in the CNS.

Melatonin and regulation of miRNAs: novel targeted therapy for cancerous and noncancerous disease

miRNAs, small noncoding RNAs with crucial diagnostic and prognostic capabilities, play essential therapeutic roles in different human diseases. These biomarkers are involved in several biological mechanisms and are responsible for the regulation of multiple genes expressions in cells. miRNA-based therapy has shown a very bright future in the case of clinical interventions. Melatonin, the main product of the pineal gland, is a multifunctional neurohormone with numerous therapeutic potentials in human diseases. Melatonin is able to regulate miRNAs in different pathologies such as malignant and nonmalignant diseases, which can be considered as a novel kind of targeted therapy. Herein, this review discusses possible therapeutic utility of melatonin for the regulation of miRNAs in various pathological conditions.

Melatonin Protects Cholangiocytes from Oxidative Stress-Induced Proapoptotic and Proinflammatory Stimuli via miR-132 and miR-34

Biosynthesis of melatonin by cholangiocytes is essential for maintaining the function of biliary epithelium. However, this cytoprotective mechanism appears to be impaired in primary biliary cholangitis (PBC). MiR-132 has emerged as a mediator of inflammation in chronic liver diseases. The effect of melatonin on oxidative stress and bile acid-induced apoptosis was also examined in cholangiocyes overexpressing miR506, as a PBC-like cellular model. In PBC patients the serum levels of melatonin were found increased in comparison to healthy controls. Whereas, in cholangiocytes within cirrhotic PBC livers the melatonin biosynthetic pathway was substantially suppressed even though the expressions of melatonin rate-limiting enzyme aralkylamine N-acetyltransferase (AANAT), and CK-19 (marker of cholangiocytes) were enhanced. In cholangiocytes exposed to mitochondrial oxidative stress melatonin decreased the expression of proapoptotic stimuli (PTEN, Bax, miR-34), which was accompanied by the inhibition of a pivotal mediator of inflammatory response Nf-κB-p65 and the activation of antiapoptotic signaling (miR-132, Bcl2). Similarly, melatonin reduced bile acid-induced proapoptotic caspase 3 and Bim levels. In summary, the insufficient hepatic expression of melatonin in PBC patients may predispose cholangiocytes to oxidative stress-related damage. Melatonin, via epigenetic modulation, was able to suppress NF-κB signaling activation and protect against biliary cells apoptotic signaling.

Competing Endogenous RNA Networks as Biomarkers in Neurodegenerative Diseases

Protein aggregation is classically considered the main cause of neuronal death in neurodegenerative diseases (NDDs). However, increasing evidence suggests that alteration of RNA metabolism is a key factor in the etiopathogenesis of these complex disorders. Non-coding RNAs are the major contributor to the human transcriptome and are particularly abundant in the central nervous system, where they have been proposed to be involved in the onset and development of NDDs. Interestingly, some ncRNAs (such as lncRNAs, circRNAs and pseudogenes) share a common functionality in their ability to regulate gene expression by modulating miRNAs in a phenomenon known as the competing endogenous RNA mechanism. Moreover, ncRNAs are found in body fluids where their presence and concentration could serve as potential non-invasive biomarkers of NDDs. In this review, we summarize the ceRNA networks described in Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and spinocerebellar ataxia type 7, and discuss their potential as biomarkers of these NDDs. Although numerous studies have been carried out, further research is needed to validate these complex interactions between RNAs and the alterations in RNA editing that could provide specific ceRNET profiles for neurodegenerative disorders, paving the way to a better understanding of these diseases.

Melatonin regulates Aβ production/clearance balance and Aβ neurotoxicity: A potential therapeutic molecule for Alzheimer's disease

Alzheimer's disease (AD) is an age-related neurodegenerative disease with multiple predisposing factors and complicated pathogenesis. Aβ peptide is one of the most important pathogenic factors in the etiology of AD. Accumulating evidence indicates that the imbalance of Aβ production and Aβ clearance in the brain of AD patients leads to Aβ deposition and neurotoxic Aβ oligomer formation. Melatonin shows a potent neuroprotective effect and can prevent or slow down the progression of AD, supporting the view that melatonin is a potential therapeutic molecule for AD. Melatonin modulates the regulatory network of secretase expression and affects the function of secretase, thereby inhibiting amyloidogenic APP processing and Aβ production. Additionally, melatonin ameliorates Aβ-induced neurotoxicity and probably promotes Aβ clearance through glymphatic-lymphatic drainage, BBB transportation and degradation pathways. In this review, we summarize and discuss the role of melatonin against Aβ-dependent AD pathogenesis. We explore the potential cellular and molecular mechanisms of melatonin on Aβ production and assembly, Aβ clearance, Aβ neurotoxicity and circadian cycle disruption. We summarize multiple clinical trials of melatonin treatment in AD patients, showing that melatonin has a promising effect on improving sleep quality and cognitive function. This review aims to stimulate further research on melatonin as a potential therapeutic agent for AD.

The Role of microRNAs in Metabolic Syndrome-Related Oxidative Stress

Oxidative stress (OxS) is the cause and the consequence of metabolic syndrome (MetS), the incidence and economic burden of which is increasing each year. OxS triggers the dysregulation of signaling pathways associated with metabolism and epigenetics, including microRNAs, which are biomarkers of metabolic disorders. In this review, we aimed to summarize the current knowledge regarding the interplay between microRNAs and OxS in MetS and its components. We searched PubMed and Google Scholar to summarize the most relevant studies. Collected data suggested that different sources of OxS (e.g., hyperglycemia, insulin resistance (IR), hyperlipidemia, obesity, proinflammatory cytokines) change the expression of numerous microRNAs in organs involved in the regulation of glucose and lipid metabolism and endothelium. Dysregulated microRNAs either directly or indirectly affect the expression and/or activity of molecules of antioxidative signaling pathways (SIRT1, FOXOs, Keap1/Nrf2) along with effector enzymes (e.g., GPx-1, SOD1/2, HO-1), ROS producers (e.g., NOX4/5), as well as genes of numerous signaling pathways connected with inflammation, insulin sensitivity, and lipid metabolism, thus promoting the progression of metabolic imbalance. MicroRNAs appear to be important epigenetic modifiers in managing the delicate redox balance, mediating either pro- or antioxidant biological impacts. Summarizing, microRNAs may be promising therapeutic targets in ameliorating the repercussions of OxS in MetS.

Melatonin Act as an Antidepressant via Attenuation of Neuroinflammation by Targeting Sirt1/Nrf2/HO-1 Signaling

Physical or psychological stress can cause an immunologic imbalance that disturbs the central nervous system followed by neuroinflammation. The association between inflammation and depression has been widely studied in recent years, though the molecular mechanism is still largely unknown. Thus, targeting the signaling pathways that link stress to neuroinflammation might be a useful strategy against depression. The current study investigated the protective effect of melatonin against lipopolysaccharide (LPS)-induced neuroinflammation and depression. Our results showed that LPS treatment significantly induced depressive-like behavior in mice. Moreover, LPS-treatment enhanced oxidative stress, pro-inflammatory cytokines including TNFα, IL-6, and IL-1β, NF-κB phosphorylation, and glial cell activation markers including GFAP and Iba-1 in the brain of mice. Melatonin treatment significantly abolished the effect of LPS, as indicated by improved depressive-like behaviors, reduced cytokines level, reduced oxidative stress, and normalized LPS-altered Sirt1, Nrf2, and HO-1 expression. However, the melatonin protective effects were reduced after luzindole administration. Collectively, it is concluded that melatonin receptor-dependently protects against LPS-induced depressive-like behaviors via counteracting LPS-induced neuroinflammation.

Transcriptomics in Alzheimer's Disease: Aspects and Challenges

Alzheimer's disease (AD) is the most common cause of dementia. Although the heritability of AD is high, the knowledge of the disease-associated genes, their expression, and their disease-related pathways remain limited. Hence, finding the association between gene dysfunctions and pathological mechanisms, such as neuronal transports, APP processing, calcium homeostasis, and impairment in mitochondria, should be crucial. Emerging studies have revealed that changes in gene expression and gene regulation may have a strong impact on neurodegeneration. The mRNA-transcription factor interactions, non-coding RNAs, alternative splicing, or copy number variants could also play a role in disease onset. These facts suggest that understanding the impact of transcriptomes in AD may improve the disease diagnosis and also the therapies. In this review, we highlight recent transcriptome investigations in multifactorial AD, with emphasis on the insights emerging at their interface.

Hypothermia protects neurons against ischemia/reperfusion-induced pyroptosis via m6A-mediated activation of PTEN and the PI3K/Akt/GSK-3β signaling pathway

Cerebral ischemia/reperfusion (I/R) injury often leads to irreversible neuronal injury and even death, and hypothermia is the only therapeutic method that has been proven to be effective. However, the molecular mechanisms underlying the effect of hypothermia treatment on I/R injury have not been fully elucidated. In the present study, we aimed to evaluate the neuroprotective effects and mechanisms of hypothermia against hypoxia/reoxygenation (H/R)-induced neuronal damage. Primary hippocampal neurons were exposed to H/R and were then treated with hypothermia. We observed that hypothermia significantly increased cellular viability, downregulated the expression of pyroptosis-related proteins-including NLR pyrin domain containing 3 (NLRP3), apoptotic speck-like protein containing CARD (ASC), cleaved Caspase-1, and Gasdermin-D (GsdmD) p30-and reduced secretion of the pro-inflammatory cytokines, IL-1β and IL-18. Additionally, pretreatment with MCC950, a specific small-molecule inhibitor of the NLRP3 inflammasome, yielded a protective effect on cellular viability that was comparable to that of hypothermia treatment. Furthermore, hypothermia also significantly elevated the expression level of phosphatase and tensin homologous protein (PTEN) and activated the phosphorylation levels of protein kinase B (Akt) and glycogen synthase kinase-3β (GSK-3β). These protective effects of hypothermia on pyroptosis-related proteins and pro-inflammatory cytokines were partially reversed by the specific PI3K/Akt inhibitor, LY294002. Moreover, the methylated level of PTEN mRNA was elevated in hippocampal neurons upon H/R, whereas this level remained stable in the hypothermia group. Therefore, our findings suggest that hypothermia protects neurons against neuronal H/R-induced pyroptosis, and that m6A-mediated activation of PTEN and the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt/GSK-3β signaling pathway may play crucial roles during this process.

Cerebral Amyloid Angiopathy, Alzheimer's Disease and MicroRNA: miRNA as Diagnostic Biomarkers and Potential Therapeutic Targets

The protein molecules must fold into unique conformations to acquire functional activity. Misfolding, aggregation, and deposition of proteins in diverse organs, the so-called "protein misfolding disorders (PMDs)", represent the conformational diseases with highly ordered assemblies, including oligomers and fibrils that are linked to neurodegeneration in brain illnesses such as cerebral amyloid angiopathy (CAA) and Alzheimer's disease (AD). Recent studies have revealed several aspects of brain pathology in CAA and AD, but both the classification and underlying mechanisms need to be further refined. MicroRNAs (miRNAs) are critical regulators of gene expression at the post-transcriptional level. Increasing evidence with the advent of RNA sequencing technology suggests possible links between miRNAs and these neurodegenerative disorders. To provide insights on the small RNA-mediated regulatory circuitry and the translational significance of miRNAs in PMDs, this review will discuss the characteristics and mechanisms of the diseases and summarize circulating or tissue-resident miRNAs associated with AD and CAA.

Effect of melatonin on Aβ42 induced changes in the mitochondrial function related to Alzheimer's disease in Drosophila melanogaster

Alzheimers's disease is one of the alarming neurodegenerative disease and it is of global concern.The hallmarks of the disease are the amyloid beta (Aβ) aggregation and presence of neurofibrillary tangles (NFTs). The interaction of Aβ with macromolecular targets affects the normal cellular functions. The amyloid peptide interaction with cellular surfaces may trigger the intracellular cascades of signalling. Interaction of Aβ with mitochondria leads to the generation of free radicals. Many studies have suggested the involvement of mitochondrial dysfunction in Alzheimer's disease. Melatonin prevents mitochondria stress and by means of activating the antioxidant systems it protects the death of neurons. Although the study have been already conducted on Aβ42 infused or injury induced animal models but till date there is no reports of such studies on transgenic model of Drosophila melanogaster. In the present study, we have taken UAS/Gal4 system for the development of transgenic flies that overexpress Aβ42 in the brain of Drosophila. With the help of these transgenic flies we have analyse different experiments like behavioural parameters, oxidative stress parameters and protein expression through western blotting in the presence of melatonin. We have found that melatonin significantly ameliorated the toxicity caused by the Aβ42 overexpression. Thus the present study could be beneficial to find out the role of melatonin in transgenic flies overexpressing human Aβ42.

MicroRNAs in Alzheimer's Disease

Alzheimer’s disease (AD) is a progressive and devastating neurodegenerative disorder. It is the leading cause of dementia in the world’s rapidly growing aging population. The characteristics of AD are memory loss and cognitive impairment, meaning patients cannot carry out their daily activities independently. The increase of AD cases poses heavy burdens on families, society and the economy. Despite frequent efforts being made to research the etiology of AD, the causes of AD remain unknown, and no curative treatments are available yet. The pathological hallmarks of AD are amyloid plaques and neurofibrillary tangles in the brain. MicroRNAs are endogenous ∼22 nucleotides non-coding RNAs that could regulate gene expression at a post-transcriptional level by transcript degradation or translation repression. MicroRNAs are involved in many biological processes and diseases, particularly multifactorial diseases, providing an excellent tool with which to research the mechanisms of these diseases. AD is a multifactorial disorder, and accumulating evidence shows that microRNAs play a critical role in the pathogenesis of AD. In this review, we will highlight the effect of microRNAs in different pathological processes throughout AD progression.

Melatonin induces mechanisms of brain resilience against neurodegeneration

Melatonin is an endogenous pleiotropic molecule which orchestrates regulatory functions and protective capacity against age-related ailments. The increase in circulating levels of melatonin through dietary supplements intensifies its health benefits. Investigations in animal models have shown that melatonin protects against Alzheimer's disease (AD)-like pathology, although clinical studies have not been conclusive. We hypothesized that melatonin induces changes in the brain that prevent or attenuate AD by increasing resilience. Therefore, we treated healthy nontransgenic (NoTg) and AD transgenic (3xTg-AD) 6-month-old mice with a daily dose of 10 mg/kg of melatonin until 12 months of age. As expected, melatonin reversed cognitive impairment and dementia-associated behaviors of anxiety and apathy and reduced amyloid and tau burden in 3xTg-AD mice. Remarkably, melatonin induced cognitive enhancement and higher wellness level-related behavior in NoTg mice. At the mechanism level, NF-κB and proinflammatory cytokine expressions were decreased in both NoTg and 3xTg-AD mice. The SIRT1 pathway of longevity and neuroprotection was also activated in both mouse strains after melatonin dosing. Furthermore, we explored new mechanisms and pathways not previously associated with melatonin treatment such as the ubiquitin-proteasome proteolytic system and the recently proposed neuroprotective Gas6/TAM pathway. The upregulation of proteasome activity and the modulation of Gas6 and its receptors by melatonin were similarly displayed by both NoTg and 3xTg-AD mice. Therefore, these results confirm the potential of melatonin treatment against AD pathology, by way of opening new pathways in its mechanisms of action, and demonstrating that melatonin induces cognitive enhancement and brain resilience against neurodegenerative processes.

miR-132-3p boosts caveolae-mediated transcellular transport in glioma endothelial cells by targeting PTEN/PI3K/PKB/Src/Cav-1 signaling pathway

Blood-brain tumor barrier (BTB) impedes the transportation of antitumor therapeutic drugs into brain tumors. Its mechanism is still unknown, but learning how to improve the BTB permeability is critical for drug intervention. Recently, microRNAs (miRNAs) have appeared as regulation factors of numerous biologic processes and therapeutic targets of diverse diseases. In this study, we have identified that miR-132-3p is an essential miRNA by increasing the transcellular transport through the BTB. We found that miR-132-3p expression was significantly up-regulated in glioma endothelial cells (GECs). Furthermore we showed that miR132-3p⁺ greatly induced the endocytosis of cholera toxin subunit B and FITC-bovine serum albumin and up-regulated the expression of p-PKB, p-Src and Tyr14 phosphorylation of caveolin-1 (p-Cav-1), while phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression was markedly down-regulated in GECs. Our results identify PTEN as a direct and functional downstream target of miR-132-3p, which is involved in the regulation of p-PKB, p-Src, and p-Cav-1. The inhibitors for PI3K and Src significantly reversed the increase of p-Cav-1 induced by miR-132-3p. Moreover, overexpression of PTEN greatly reduced the endocytosis of cholera toxin subunit B and the up-regulation of p-Cav-1 induced by agomiR132-3p, suggesting that miR132-3p⁺ increases the endothelial permeability by inhibition of PTEN expression. In addition, miR132-3p⁺ significantly increased the delivery of doxorubicin across the BTB in vitro and contributed to the accumulation of doxorubicin within the brain tumor tissue. Our results show that miR-132-3p contributes to the increased permeability of BTB by targeting PTEN/PI3K/PKB/Src/Cav-1, thereby revealing a novel drug target for the treatment of brain gliomas.-Gu, Y., Cai, R., Zhang, C., Xue, Y., Pan, Y., Wang, J., Zhang, Z. miR-132-3p boosts caveolae-mediated transcellular transport in glioma endothelial cells by targeting PTEN/PI3K/PKB/Src/Cav-1 signaling pathway.