miR-107 regulates granulin/progranulin with implications for traumatic brain injury and neurodegenerative disease

A role for astrocytic miR-129-5p in frontotemporal dementia

Frontotemporal dementia is a debilitating neurodegenerative disorder characterized by frontal and temporal lobe degeneration, resulting in behavioral changes, language difficulties, and cognitive decline. In this study, smallRNA sequencing was conducted on postmortem brain tissues obtained from the frontal and temporal of FTD patients with GRN, MAPT, or C9ORF72 mutations. Our analysis identified miR-129-5p as consistently deregulated across all analyzed mutation conditions and brain regions. Functional investigations in in-vitro models revealed a novel role of miR-129-5p in astrocytes, where its loss led to neuroinflammation and impaired neuronal support functions, including reduced glutamate uptake. Depletion of miR-129-5p in astrocytes also resulted in the loss of neuronal spines and altered neuronal network activity in a cell culture system. These findings highlight miR-129-5p as a potential therapeutic target in neurodegenerative diseases and also sheds light on the role of astrocytes in Frontotemporal dementia pathogenesis.

Coenzyme Q10 alleviates AlCl3 and D-galactose induced Alzheimer via modulating oxidative burden and TLR-4/MAPK pathways and regulation microRNA in rat brain

Alzheimer's disease (ad) is the most progressive form of neurodegenerative disease resulting in cognitive and non-cognitive deficits. Coenzyme Q10 (CoQ10) is an anti-inflammatory and anti-oxidative stress supplement that can improve inflammation and oxidative stress associated with ad. This study aimed to explore the protective potential of coenzyme Q10 (CoQ10). It also sought to uncover any synergistic effects when combined with donepezil, an acetylcholinesterase inhibitor, in treating Alzheimer's disease in rats, focusing on the modulation of the TLR-4/MAPK pathway and regulation of microRNA. The experiment involved seventy rats categorized into different groups: control, Reference group (donepezil 10 mg/kg/P.O.), CoQ10 alone (1,200 mg/kg/P.O.), ad-model (D-galactose (120 mg/kg/i.p) + Alcl3 (50 mg/kg/P.O.)), donepezil co-treatment, CoQ10 co-treatment, and CoQ10 + donepezil co-treatment. Behavioral parameter was defined using the Morris-Maze test (MMT) and various assessments, such as GABA, oxidative stress, Aβ1-42, ion homeostasis, toll-like receptor-4 (TLR-4), mitogen-activated protein kinase-1 (MAPK-1), micro-RNA (mir-106b, mir-107, and mir-9) were measured. Immunohistological staining was used to assess structural abnormalities in hippocampus. CoQ10 treatment demonstrated memory improvement, enhanced locomotion, and increased neuronal differentiation, mainly through the activation of the TLR-4/MAPK pathway and regulation of mir-106b, mir-107, and mir-9.

Highlights

Coenzyme Q10 (CoQ10) improved the rats' passive avoidance memory impairment caused by D-gal and AlCl3. ad led to the alteration of the TLR-4/MAPK pathways.CoQ10 as a protective agent, diminishes oxidative burden, improve ion homeostasis.CoQ10 counteracts Alzheimer's disease by enhancing neurotransmitter parameter and regulating the MicroRNA.CoQ10 lowered accumulation of Aβ plaque in the hippocampal neurons of D-Gal and AlCl3-treated rats.One promising therapeutic method was the combination of donepezil and CoQ10 therapy.

Unveiling the predictive power of biomarkers in traumatic brain injury: A narrative review focused on clinical outcomes

Traumatic brain injury (TBI) has long-term consequences, including neurodegenerative disease risk. Current diagnostic tools are limited in detecting subtle brain damage. This review explores emerging biomarkers for TBI, including those related to neuronal injury, inflammation, EVs, and ncRNAs, evaluating their potential to predict clinical outcomes like mortality, recovery, and cognitive impairment. It addresses challenges and opportunities for implementing biomarkers in clinical practice, aiming to improve TBI diagnosis, prognosis, and treatment.

The bioenergetics of traumatic brain injury and its long-term impact for brain plasticity and function

Mitochondria provide the energy to keep cells alive and functioning and they have the capacity to influence highly complex molecular events. Mitochondria are essential to maintain cellular energy homeostasis that determines the course of neurological disorders, including traumatic brain injury (TBI). Various aspects of mitochondria metabolism such as autophagy can have long-term consequences for brain function and plasticity. In turn, mitochondria bioenergetics can impinge on molecular events associated with epigenetic modifications of DNA, which can extend cellular memory for a long time. Mitochondrial dysfunction leads to pathological manifestations such as oxidative stress, inflammation, and calcium imbalance that threaten brain plasticity and function. Hence, targeting mitochondrial function may have great potential to lessen the outcomes of TBI.

Granulin in renal tubular epithelia is associated with interstitial inflammation and activates the TLR9-IFN-α pathway in lupus nephritis

OBJECTIVE

This study aimed to investigate the possible role of granulin (GRN) in activating the TLR9-IFN-α pathway in renal tubular epithelial cells (RTECs) and explore clues that RTECs regulate the micro-environment of inflammatory response in lupus nephritis (LN).

METHODS

Renal sections from 57 LN patients and 30 non-LN patients were sampled for histological study, and GRN overexpression RTECs were applied for cytological study.

RESULTS

In the histological study, GRN is highly expressed in LN RTECs with tubulointerstitial inflammation (TII) and well co-localized with TLR9. ROC analysis suggested a potential relationship between GRN expression in RTECs and therapeutic response. Moreover, IFN-α also highly expressed in LN RTECs with TII, and the intensity of IFN-α is positively correlated with the co-localization intensity of GRN and TLR9. In the cytological study, LN serum, especially serum from LN with TII, activates the expression of TLR9 in RTECs, and GRN engages the interaction of TLR9 to activate the expression of IFN-α in RTECs. While TLR9 inhibitors can suppress the expression of IFN-α in RTECs, the degree of inhibition is dose-dependent.

CONCLUSION

The expression of GRN in RTECs is associated with interstitial inflammation and therapeutic response. GRN may mediate the activation of the TLR9-IFN-α pathway in RTECs and involve in the micro-environment of inflammatory response in LN.

Sex-Biased Expression and Response of microRNAs in Neurological Diseases and Neurotrauma

Neurological diseases and neurotrauma manifest significant sex differences in prevalence, progression, outcome, and therapeutic responses. Genetic predisposition, sex hormones, inflammation, and environmental exposures are among many physiological and pathological factors that impact the sex disparity in neurological diseases. MicroRNAs (miRNAs) are a powerful class of gene expression regulator that are extensively involved in mediating biological pathways. Emerging evidence demonstrates that miRNAs play a crucial role in the sex dimorphism observed in various human diseases, including neurological diseases. Understanding the sex differences in miRNA expression and response is believed to have important implications for assessing the risk of neurological disease, defining therapeutic intervention strategies, and advancing both basic research and clinical investigations. However, there is limited research exploring the extent to which miRNAs contribute to the sex disparities observed in various neurological diseases. Here, we review the current state of knowledge related to the sexual dimorphism in miRNAs in neurological diseases and neurotrauma research. We also discuss how sex chromosomes may contribute to the miRNA sexual dimorphism phenomenon. We attempt to emphasize the significance of sexual dimorphism in miRNA biology in human diseases and to advocate a gender/sex-balanced science.

Role of regulatory non-coding RNAs in traumatic brain injury

Traumatic brain injury (TBI) is a potentially fatal health event that cannot be predicted in advance. After TBI occurs, it can have enduring consequences within both familial and social spheres. Yet, despite extensive efforts to improve medical interventions and tailor healthcare services, TBI still remains a major contributor to global disability and mortality rates. The prompt and accurate diagnosis of TBI in clinical contexts, coupled with the implementation of effective therapeutic strategies, remains an arduous challenge. However, a deeper understanding of changes in gene expression and the underlying molecular regulatory processes may alleviate this pressing issue. In recent years, the study of regulatory non-coding RNAs (ncRNAs), a diverse class of RNA molecules with regulatory functions, has been a potential game changer in TBI research. Notably, the identification of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and other ncRNAs has revealed their potential as novel diagnostic biomarkers and therapeutic targets for TBI, owing to their ability to regulate the expression of numerous genes. In this review, we seek to provide a comprehensive overview of the functions of regulatory ncRNAs in TBI. We also summarize regulatory ncRNAs used for treatment in animal models, as well as miRNAs, lncRNAs, and circRNAs that served as biomarkers for TBI diagnosis and prognosis. Finally, we discuss future challenges and prospects in diagnosing and treating TBI patients in the clinical settings.

Antisense oligonucleotides targeting the miR-29b binding site in the GRN mRNA increase progranulin translation

Heterozygous GRN (progranulin) mutations cause frontotemporal dementia (FTD) due to haploinsufficiency, and increasing progranulin levels is a major therapeutic goal. Several microRNAs, including miR-29b, negatively regulate progranulin protein levels. Antisense oligonucleotides (ASOs) are emerging as a promising therapeutic modality for neurological diseases, but strategies for increasing target protein levels are limited. Here, we tested the efficacy of ASOs as enhancers of progranulin expression by sterically blocking the miR-29b binding site in the 3' UTR of the human GRN mRNA. We found 16 ASOs that increase progranulin protein in a dose-dependent manner in neuroglioma cells. A subset of these ASOs also increased progranulin protein in iPSC-derived neurons and in a humanized GRN mouse model. In FRET-based assays, the ASOs effectively competed for miR-29b from binding to the GRN 3' UTR RNA. The ASOs increased levels of newly synthesized progranulin protein by increasing its translation, as revealed by polysome profiling. Together, our results demonstrate that ASOs can be used to effectively increase target protein levels by partially blocking miR binding sites. This ASO strategy may be therapeutically feasible for progranulin-deficient FTD as well as other conditions of haploinsufficiency.

Progranulin and GPNMB: interactions in endo-lysosome function and inflammation in neurodegenerative disease

BACKGROUND

Alterations in progranulin (PGRN) expression are associated with multiple neurodegenerative diseases (NDs), including frontotemporal dementia (FTD), Alzheimer's disease (AD), Parkinson's disease (PD), and lysosomal storage disorders (LSDs). Recently, the loss of PGRN was shown to result in endo-lysosomal system dysfunction and an age-dependent increase in the expression of another protein associated with NDs, glycoprotein non-metastatic B (GPNMB).

MAIN BODY

It is unclear what role GPNMB plays in the context of PGRN insufficiency and how they interact and contribute to the development or progression of NDs. This review focuses on the interplay between these two critical proteins within the context of endo-lysosomal health, immune function, and inflammation in their contribution to NDs.

SHORT CONCLUSION

PGRN and GPNMB are interrelated proteins that regulate disease-relevant processes and may have value as therapeutic targets to delay disease progression or extend therapeutic windows.

MicroRNA expression in extracellular vesicles as a novel blood-based biomarker for Alzheimer's disease

INTRODUCTION

Brain cell-derived small extracellular vesicles (sEVs) in blood offer unique cellular and molecular information related to the onset and progression of Alzheimer's disease (AD). We simultaneously enriched six specific sEV subtypes from the plasma and analyzed a selected panel of microRNAs (miRNAs) in older adults with/without cognitive impairment.

METHODS

Total sEVs were isolated from the plasma of participants with normal cognition (CN; n = 11), mild cognitive impairment (MCI; n = 11), MCI conversion to AD dementia (MCI-AD; n = 6), and AD dementia (n = 11). Various brain cell-derived sEVs (from neurons, astrocytes, microglia, oligodendrocytes, pericytes, and endothelial cells) were enriched and analyzed for specific miRNAs.

RESULTS

miRNAs in sEV subtypes differentially expressed in MCI, MCI-AD, and AD dementia compared to the CN group clearly distinguished dementia status, with an area under the curve (AUC) > 0.90 and correlated with the temporal cortical region thickness on magnetic resonance imaging (MRI).

DISCUSSION

miRNA analyses in specific sEVs could serve as a novel blood-based molecular biomarker for AD.

HIGHLIGHTS

Multiple brain cell-derived small extracellular vesicles (sEVs) could be isolated simultaneously from blood. MicroRNA (miRNA) expression in sEVs could detect Alzheimer's disease (AD) with high specificity and sensitivity. miRNA expression in sEVs correlated with cortical region thickness on magnetic resonance imaging (MRI). Altered expression of miRNAs in sEVCD31 and sEVPDGFRβ suggested vascular dysfunction. miRNA expression in sEVs could predict the activation state of specific brain cell types.

The relationship between prognosis of patients with traumatic brain injury and microRNA biogenesis proteins

BACKGROUND

This study aims to investigate whether the expression levels of proteins involved in microRNA (miRNA) biogenesis vary in early- and late-stage traumatic brain injury (TBI) patients and to evaluate its effect on prognosis.

METHODS

Dicer, Drosha, DiGeorge Syndrome Critical Region eight (DGCR8), Exportin5 (XPO5), and Argonaute2 (AGO2) levels were measured in the blood samples of severe TBI patients collected 4-6 h and 72 h after the trauma and compared with the control group. Prognostic follow-up of the patients was performed using the Glasgow Coma Scale score.

RESULTS

There were no statistically significant changes in the expression of the miRNA biogenesis proteins Dicer, Drosha, DGCR8, XPO5, and AGO2 in patients with severe TBI. However, the expression of Dicer increased in the patients who improved from the severe TBI grade to the mild TBI grade, and the expression of AGO2 decreased in most of these patients. The Dicer expression profile was found to increase in patients discharged from the intensive care unit in a short time.

CONCLUSION

MicroRNAs and their biogenesis proteins may guide prognostic and therapeutic decisions for patients with TBI in the future.

Non-coding RNAs and Exosomal Non-coding RNAs in Traumatic Brain Injury: the Small Player with Big Actions

Nowadays, there is an increasing concern regarding traumatic brain injury (TBI) worldwide since substantial morbidity is observed after it, and the long-term consequences that are not yet fully recognized. A number of cellular pathways related to the secondary injury in brain have been identified, including free radical production (owing to mitochondrial dysfunction), excitotoxicity (regulated by excitatory neurotransmitters), apoptosis, and neuroinflammatory responses (as a result of activation of the immune system and central nervous system). In this context, non-coding RNAs (ncRNAs) maintain a fundamental contribution to post-transcriptional regulation. It has been shown that mammalian brains express high levels of ncRNAs that are involved in several brain physiological processes. Furthermore, altered levels of ncRNA expression have been found in those with traumatic as well non-traumatic brain injuries. The current review highlights the primary molecular mechanisms participated in TBI that describes the latest and novel results about changes and role of ncRNAs in TBI in both clinical and experimental research.

Preclinical Interventions in Mouse Models of Frontotemporal Dementia Due to Progranulin Mutations

Heterozygous loss-of-function mutations in progranulin (GRN) cause frontotemporal dementia (FTD), a leading cause of early-onset dementia characterized clinically by behavioral, social, and language deficits. There are currently no FDA-approved therapeutics for FTD-GRN, but this has been an active area of investigation, and several approaches are now in clinical trials. Here, we review preclinical development of therapies for FTD-GRN with a focus on testing in mouse models. Since most FTD-GRN-associated mutations cause progranulin haploinsufficiency, these approaches focus on raising progranulin levels. We begin by considering the disorders associated with altered progranulin levels, and then review the basics of progranulin biology including its lysosomal, neurotrophic, and immunomodulatory functions. We discuss mouse models of progranulin insufficiency and how they have been used in preclinical studies on a variety of therapeutic approaches. These include approaches to raise progranulin expression from the normal allele or facilitate progranulin production by the mutant allele, as well as approaches to directly increase progranulin levels by delivery across the blood-brain barrier or by gene therapy. Several of these approaches have entered clinical trials, providing hope that new therapies for FTD-GRN may be the next frontier in the treatment of neurodegenerative disease.

Gastrodin ameliorates the lipopolysaccharide-induced neuroinflammation in mice by downregulating miR-107-3p

Background: Neuroinflammation plays a pivotal role in the pathogenesis of Central Nervous System (CNS) diseases. The phenolic glucoside gastrodin (GAS), has been known to treat CNS disorders by exerting anti-inflammatory activities. Our aim was to investigate the potential neuroprotective mechanisms of GAS on lipopolysaccharide (LPS)-induced mice. Methods: Male C57BL/6J mice were treated by LPS, before which GAS was adminisrated. The behavior tests such as forced swim test, tail suspension test, and elevated plus maze were performed to evaluate depressive-anxiety-like behaviors. A high-throughput sequencing (HTS) analysis was performed to screen out distinctive miRNAs which were validated using quantitative real-time PCR. Then, miRNA agomir or NC was injected stereotaxically into hippocampus of mice to explore the role of miRNA on GAS in response to LPS. Furthermore, Immunofluorescence and the hematoxylin and eosin (H&E) staining were employed to observe the cellular morphology. The protein levels of pro-inflammatory factors were evaluated by western blot. Finally, the target mRNA of miRNA was predicted using bioinformatics analysis. GO and KEGG enrichment analyses were conducted to clarify the potential function of target protein, which were visualized by bubble charts. Results: The behavioral data showed that mice in the LPS group had obvious depressive-anxiety-like behaviors, and 100 mg/kg GAS could improve these behavioral changes and alleviate the levels of pro-inflammatory cytokines in the hippocampus when mice were exposed to LPS for 6 h. Meanwhile, LPS-induced microglia and astrocyte activation in the CA1, CA2, CA3, and DG regions of the hippocampus were also reversed by GAS. Furthermore, miR-107-3p were screened out and verified for GAS in response to LPS. Importantly, miR-107-3p overexpression negatively abrogated the neuroprotective effects of GAS. Moreover, KPNA1 might be the target molecular of miR-107-3p. KPNA1 might regulate 12 neuroinflammation-related genes, which were mainly involved in cytokine-mediated signaling pathway. Conclusion: These results suggested that GAS might alleviate the LPS-induced neuroinflammation and depressive-anxiety-like behaviors in mice by downregulating miR-107-3p and upregulating the downstream target KPNA1. The indicates miR-107-3p may provide a new strategy for the treatment of CNS diseases.

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.

MiR-107 inhibits the sprouting of intersegmental vessels of zebrafish embryos

MicroRNAs (miRNAs) play important roles in various biological processes. Our previous study showed that inhibition of MTOR with rapamycin treatment suppressed human endothelial cell tube formation, concomitant with the down-regulation of miR-107. Similarly, inhibition of Ztor by rapamycin also suppressed vascular development in zebrafish embryos. To gain a better understanding of the role of miR-107 and MTOR in vascular development, the present study sought to validate its function by over-expressing miR-107 in zebrafish embryos via microinjection with mimic miR-107 duplexes. Alkaline phosphatase (ALP) staining was used to visualise blood vessels in the zebrafish embryo, and expressions of Pten, Ztor and Rap1 were investigated by immunoblotting. Over-expression of miR-107 in zebrafish embryos inhibited the sprouting of intersegmental vessels (ISVs) with concomitant down-regulation of phosphorylated Rps6 expression, which confirmed the inhibition of Ztor signalling. As expected, pten, which is the target of miR-107, was down-regulated. Interestingly, Rap1, a small GTPase protein that is involved in intersomitic vessels sprouting during angiogenesis, was also down-regulated when miR-107 was over-expressed. Overall, our findings suggest that miR-107 and Ztor-mediated suppression of vascular development in zebrafish embryo involves Rap1.

Role of miRNAs in Neurodegeneration: From Disease Cause to Tools of Biomarker Discovery and Therapeutics

Neurodegenerative diseases originate from neuronal loss in the central nervous system (CNS). These debilitating diseases progress with age and have become common due to an increase in longevity. The National Institute of Environmental Health Science’s 2021 annual report suggests around 6.2 million Americans are living with Alzheimer’s disease, and there is a possibility that there will be 1.2 million Parkinson’s disease patients in the USA by 2030. There is no clear-cut universal mechanism for identifying neurodegenerative diseases, and therefore, they pose a challenge for neurobiology scientists. Genetic and environmental factors modulate these diseases leading to familial or sporadic forms. Prior studies have shown that miRNA levels are altered during the course of the disease, thereby suggesting that these noncoding RNAs may be the contributing factor in neurodegeneration. In this review, we highlight the role of miRNAs in the pathogenesis of neurodegenerative diseases. Through this review, we aim to achieve four main objectives: First, we highlight how dysregulation of miRNA biogenesis led to these diseases. Second, we highlight the computational or bioinformatics tools required to identify the putative molecular targets of miRNAs, leading to biological molecular pathways or mechanisms involved in these diseases. Third, we focus on the dysregulation of miRNAs and their target genes leading to several neurodegenerative diseases. In the final section, we highlight the use of miRNAs as potential diagnostic biomarkers in the early asymptomatic preclinical diagnosis of these age-dependent debilitating diseases. Additionally, we discuss the challenges and advances in the development of miRNA therapeutics for brain targeting. We list some of the innovative strategies employed to deliver miRNA into target cells and the relevance of these viral and non-viral carrier systems in RNA therapy for neurodegenerative diseases. In summary, this review highlights the relevance of studying brain-enriched miRNAs, the mechanisms underlying their regulation of target gene expression, their dysregulation leading to progressive neurodegeneration, and their potential for biomarker marker and therapeutic intervention. This review thereby highlights ways for the effective diagnosis and prevention of these neurodegenerative disorders in the near future.

MicroRNA-Target Interaction Regulatory Network in Alzheimer's Disease

Alzheimer’s Disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia; however, early diagnosis of the disease is challenging. Research suggests that biomarkers found in blood, such as microRNAs (miRNA), may be promising for AD diagnostics. Experimental data on miRNA–target interactions (MTI) associated with AD are scattered across databases and publications, thus making the identification of promising miRNA biomarkers for AD difficult. In response to this, a list of experimentally validated AD-associated MTIs was obtained from miRTarBase. Cytoscape was used to create a visual MTI network. STRING software was used for protein–protein interaction analysis and mirPath was used for pathway enrichment analysis. Several targets regulated by multiple miRNAs were identified, including: BACE1, APP, NCSTN, SP1, SIRT1, and PTEN. The miRNA with the highest numbers of interactions in the network were: miR-9, miR-16, miR-34a, miR-106a, miR-107, miR-125b, miR-146, and miR-181c. The analysis revealed seven subnetworks, representing disease modules which have a potential for further biomarker development. The obtained MTI network is not yet complete, and additional studies are needed for the comprehensive understanding of the AD-associated miRNA targetome.

The biological significance and clinical utility of emerging blood biomarkers for traumatic brain injury

HUIBREGTSE, M.E, Bazarian, J.J., Shultz, S.R., and Kawata K. The biological significance and clinical utility of emerging blood biomarkers for traumatic brain injury. NEUROSCI BIOBEHAV REV XX (130) 433-447, 2021.- Blood biomarkers can serve as objective measures to gauge traumatic brain injury (TBI) severity, identify patients at risk for adverse outcomes, and predict recovery duration, yet the clinical use of blood biomarkers for TBI is limited to a select few and only to rule out the need for CT scanning. The biomarkers often examined in neurotrauma research are proteomic markers, which can reflect a range of pathological processes such as cellular damage, astrogliosis, or neuroinflammation. However, proteomic blood biomarkers are vulnerable to degradation, resulting in short half-lives. Emerging biomarkers for TBI may reflect the complex genetic and neurometabolic alterations that occur following TBI that are not captured by proteomics, are less vulnerable to degradation, and are comprised of microRNA, extracellular vesicles, and neurometabolites. Therefore, this review aims to summarize our understanding of how biomarkers for brain injury escape the brain parenchymal space and appear in the bloodstream, update recent research findings in several proteomic biomarkers, and characterize biological significance and examine clinical utility of microRNA, extracellular vesicles, and neurometabolites.

MicroRNAs as Biomarkers for Predicting Complications following Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a high mortality hemorrhagic stroke that affects nearly 30,000 patients annually in the United States. Approximately 30% of aSAH patients die during initial hospitalization and those who survive often carry poor prognosis with one in five having permanent physical and/or cognitive disabilities. The poor outcome of aSAH can be the result of the initial catastrophic event or due to the many acute or delayed neurological complications, such as cerebral ischemia, hydrocephalus, and re-bleeding. Unfortunately, no effective biomarker exists to predict or diagnose these complications at a clinically relevant time point when neurologic injury can be effectively treated and managed. Recently, a number of studies have demonstrated that microRNAs (miRNAs) in extracellular biofluids are highly associated with aSAH and complications. Here we provide an overview of the current research on relevant human studies examining the correlation between miRNAs and aSAH complications and discuss the potential application of using miRNAs as biomarkers in aSAH management.

Tweaking Progranulin Expression: Therapeutic Avenues and Opportunities

Frontotemporal dementia (FTD) is a neurodegenerative disease, leading to behavioral changes and language difficulties. Heterozygous loss-of-function mutations in progranulin (GRN) induce haploinsufficiency of the protein and are associated with up to one-third of all genetic FTD cases worldwide. While the loss of GRN is primarily associated with neurodegeneration, the biological functions of the secreted growth factor-like protein are more diverse, ranging from wound healing, inflammation, vasculogenesis, and metabolic regulation to tumor cell growth and metastasis. To date, no disease-modifying treatments exist for FTD, but different therapeutic approaches to boost GRN levels in the central nervous system are currently being developed (including AAV-mediated GRN gene delivery as well as anti-SORT1 antibody therapy). In this review, we provide an overview of the multifaceted regulation of GRN levels and the corresponding therapeutic avenues. We discuss the opportunities, advantages, and potential drawbacks of the diverse approaches. Additionally, we highlight the therapeutic potential of elevating GRN levels beyond patients with loss-of-function mutations in GRN.

Circular RNA circ_0008274 upregulates granulin to promote the progression of hepatocellular carcinoma via sponging microRNA -140-3p

Circular RNA (circRNA) features prominently in the progression of hepatocellular carcinoma (HCC), of which the biological function and potential mechanism of circ_0008274 in HCC are obscure. The present study aims to explore circ_ 0008274's biological functions and underlying mechanisms in HCC. The expressions of circ_0008274, miR-140-3p and Granulin (GRN) mRNA in HCC tissues and cells were investigated by quantitative real-time polymerase chain reaction. Besides, GRN protein expression was measured by Western blot. Furthermore, chi-square test was used to probe the interrelation between circ_0008274 expression and clinicopathological parameters. In addition, cell counting kit-8 (CCK-8) and EdU assays were applied to detect cell proliferation. Moreover, transwell assay was used to detect cell migration and invasion. What's more, bioinformatics prediction, dual-luciferase reporter gene assay and RNA Immunoprecipitation experiments were used to corroborate the targeting interrelations among circ_0008274, miR-140-3p and GRN. Herein we reported that circ_0008274 was highly expressed in HCC, and its high expression enhanced the proliferation, migration, and invasion of HCC cells, while depleting circ_0008274 inhibited the malignant biological behaviors of HCC cells. Mechanistically, circ_0008274 upregulates GRN expressions via adsorbing miR-140-3p to expedite the progression of HCC.

A Highly Predictive MicroRNA Panel for Determining Delayed Cerebral Vasospasm Risk Following Aneurysmal Subarachnoid Hemorrhage

Approximately one-third of aneurysmal subarachnoid hemorrhage (aSAH) patients develop delayed cerebral vasospasm (DCV) 3-10 days after aneurysm rupture resulting in additional, permanent neurologic disability. Currently, no validated biomarker is available to determine the risk of DCV in aSAH patients. MicroRNAs (miRNAs) have been implicated in virtually all human diseases, including aSAH, and are found in extracellular biofluids including plasma and cerebrospinal fluid (CSF). We used a custom designed TaqMan Low Density Array miRNA panel to examine the levels of 47 selected brain and vasculature injury related miRNAs in CSF and plasma specimens collected from 31 patients with or without DCV at 3 and 7 days after aSAH, as well as from eight healthy controls. The analysis of the first 18-patient cohort revealed a striking differential expression pattern of the selected miRNAs in CSF and plasma of aSAH patients with DCV from those without DCV. Importantly, this differential expression was observed at the early time point (3 days after aSAH), before DCV event occurs. Seven miRNAs were identified as reliable DCV risk predictors along with a prediction model constructed based on an array of additional 19 miRNAs on the panel. These chosen miRNAs were then used to predict the risk of DCV in a separate, testing cohort of 15 patients. The accuracy of DCV risk prediction in the testing cohort reached 87%. The study demonstrates that our novel designed miRNA panel is an effective predictor of DCV risk and has strong applications in clinical management of aSAH patients.

Long Noncoding RNA H19 Overexpression Protects against Hypoxic-Ischemic Brain Damage by Inhibiting miR-107 and Up-Regulating Vascular Endothelial Growth Factor

Long noncoding RNAs play critical roles in cellular homeostasis, and long noncoding RNA H19 (H19) is implicated in several pathologic conditions. The putative role of H19 in the pathogenesis and progression of hypoxic-ischemic brain damage (HIBD) is not yet understood. Therefore, a series of in vivo and in vitro experiments were designed to investigate the potential roles of H19 in neuronal apoptosis and cognitive dysfunction in HIBD. H19 expression was decreased in HIBD rat models established by partial occlusion of carotid artery. H19 bound to and decreased the expression of miR-107, which also increased VEGF expression. H19 overexpression reduced neuronal apoptosis and alleviated cognitive dysfunction in HIBD rats. The up-regulation of miR-107 reversed the protective effects conferred by H19. In addition, the cell model of HIBD was established by oxygen-glucose deprivation in neuronal cells used. H19 overexpression in oxygen-glucose deprivation neurons increased B-cell lymphoma-2 and decreased B-cell lymphoma-2-associated X, total and cleaved caspase-3 expressions. Taken together, the results showed that H19 expresses at a low level in HIBD. H19 overexpression decreased miR-107 and increased VEGF expression, which resulted in repressed neuronal apoptosis and alleviated cognitive dysfunction. Thus, H19 may serve as a molecular target for translational research for HIBD therapy.

Epigenetics of Alzheimer's Disease

There are currently no validated biomarkers which can be used to accurately diagnose Alzheimer's disease (AD) or to distinguish it from other dementia-causing neuropathologies. Moreover, to date, only symptomatic treatments exist for this progressive neurodegenerative disorder. In the search for new, more reliable biomarkers and potential therapeutic options, epigenetic modifications have emerged as important players in the pathogenesis of AD. The aim of the article was to provide a brief overview of the current knowledge regarding the role of epigenetics (including mitoepigenetics) in AD, and the possibility of applying these advances for future AD therapy. Extensive research has suggested an important role of DNA methylation and hydroxymethylation, histone posttranslational modifications, and non-coding RNA regulation (with the emphasis on microRNAs) in the course and development of AD. Recent studies also indicated mitochondrial DNA (mtDNA) as an interesting biomarker of AD, since dysfunctions in the mitochondria and lower mtDNA copy number have been associated with AD pathophysiology. The current evidence suggests that epigenetic changes can be successfully detected, not only in the central nervous system, but also in the cerebrospinal fluid and on the periphery, contributing further to their potential as both biomarkers and therapeutic targets in AD.

Inhibition of microRNA-203 protects against traumatic brain injury induced neural damages via suppressing neuronal apoptosis and dementia-related molecues

BACKGROUND

Traumatic brain injury (TBI) can lead to cognitive dysfunction and motor dysfunction. TBI is a potential risk factor for subsequent dementia. Hyperphosphorylation of Tau and ApoE4 has been found in patients with TBI. A significant increase in miR-203 was also found in the peripheral blood of TBI mice. Thus, we hypothesize that miR-203 inhibitor protects against neuronal damage and behavioral deficits by inhibition of Tau phosphorylation, ApoE4 expression and apoptosis.

METHODS

TBI mice were induced and treated with miR-203 inhibitor. Tau phosphorylation and ApoE4, hippocampal long-term potentiation (LTP), learning and memory, and motor function were separately detected by Western blot analysis, electrophysiology recording and behavioral assessments including Morris water maze test, beam-balance test, beam-walk test and rotarod test. Caspase-3 activity and bcl-2 expression were detected by ELISA.

RESULTS

TBI induction led to increased phosphorylation of Tau and ApoE4 expression. Administration of miR-203 inhibitor suppressed TBI induced ApoE4 expression and Tau hyperphosphorylation, rescued TBI mediated hippocampal LTP deficits and hippocampus dependent learning and memory dysfunction. miR-203 inhibitor treatment also improved motor function. In addition, miR-203 inhibitor treatment inhibited neuronal apoptosis by inhibiting caspase-3 activity and increasing bcl-2 expression.

CONCLUSION

miR-203 inhibitor treatment can rescue TBI-induced neural damage by inhibiting neuronal apoptosis and dementia markers like ApoE4 expression and Tau phosphorylation.

Blood-based Biomarkers of Alzheimer's Disease: The Long and Winding Road

BACKGROUND

Blood-based biomarkers can be very useful in formulating new diagnostic and treatment proposals in the field of dementia, especially in Alzheimer's disease (AD). However, due to the influence of several factors on the reproducibility and reliability of these markers, their clinical use is still very uncertain. Thus, up-to-date knowledge about the main blood biomarkers that are currently being studied is extremely important in order to discover clinically useful and applicable tools, which could also be used as novel pharmacological strategies for the AD treatment.

METHODS

A narrative review was performed based on the current candidates of blood-based biomarkers for AD to show the main results from different studies, focusing on their clinical applicability and association with AD pathogenesis.

OBJECTIVE

The aim of this paper was to carry out a literature review on the major blood-based biomarkers for AD, connecting them with the pathophysiology of the disease.

RESULTS

Recent advances in the search of blood-based AD biomarkers were summarized in this review. The biomarkers were classified according to the topics related to the main hallmarks of the disease such as inflammation, amyloid, and tau deposition, synaptic degeneration and oxidative stress. Moreover, molecules involved in the regulation of proteins related to these hallmarks were described, such as non-coding RNAs, neurotrophins, growth factors and metabolites. Cells or cellular components with the potential to be considered as blood-based AD biomarkers were described in a separate topic.

CONCLUSION

A series of limitations undermine new discoveries on blood-based AD biomarkers. The lack of reproducibility of findings due to the small size and heterogeneity of the study population, different analytical methods and other assay conditions make longitudinal studies necessary in this field to validate these structures, especially when considering a clinical evaluation that includes a broad panel of these potential and promising blood-based biomarkers.

MicroRNA-107 enhances radiosensitivity by suppressing granulin in PC-3 prostate cancer cells

Prostate cancer is the second leading cause of cancer-related death worldwide. Radiotherapy is often applied for the treatment, but radioresistance is a challenge in some patients. MicroRNAs have been reported to be involved in the DNA damage response induced by ionizing radiation and recent studies have reported microRNA-mediated radiosensitivity. In the present study, we found microRNA-107 (miR-107) enhanced radiosensitivity by regulating granulin (GRN) in prostate cancer (PC-3) cells. MiR-107 was downregulated and GRN was upregulated in response to ionizing radiation in PC-3 cells. Overexpression of miR-107 and knockdown of GRN promoted the sensitivity of PC3 cells to ionizing radiation. By rescue experiments of GRN, we revealed that radiosensitivity enhanced by miR-107 can be attenuated by GRN overexpression in PC-3 cells. Furthermore, we showed miR-107 enhanced radiation-induced G1/S phase arrest and G2/M phase transit, and identify delayed apoptosis by suppressing p21 and phosphorylation of CHK2. Collectively, these results highlight an unrecognized mechanism of miR-107-mediated GRN regulation in response to ionizing radiation and may advance therapeutic strategies for the treatment of prostate cancer.

Current Status of microRNA-Based Therapeutic Approaches in Neurodegenerative Disorders

MicroRNAs (miRNAs) are a key gene regulator and play essential roles in several biological and pathological mechanisms in the human system. In recent years, plenty of miRNAs have been identified to be involved in the development of neurodegenerative disorders (NDDs), thus making them an attractive option for therapeutic approaches. Hence, in this review, we provide an overview of the current research of miRNA-based therapeutics for a selected set of NDDs, either for their high prevalence or lethality, such as Alzheimer's, Parkinson's, Huntington's, Amyotrophic Lateral Sclerosis, Friedreich's Ataxia, Spinal Muscular Atrophy, and Frontotemporal Dementia. We also discuss the relevant delivery techniques, pertinent outcomes, their limitations, and their potential to become a new generation of human therapeutic drugs in the near future.

Role of microRNAs in neurodegeneration induced by environmental neurotoxicants and aging

The progressive loss of neuronal structure and functions resulting in the death of neurons is considered as neurodegeneration. Environmental toxicants induced degeneration of neurons is accelerated with aging. In adult brains, most of the neurons are post-mitotic, and their loss results in the development of diseases like amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), Alzheimer's disease (AD), and Huntington's disease (HD). Neurodegenerative diseases have several similarities at the sub-cellular and molecular levels, such as synaptic degeneration, oxidative stress, inflammation, and cognitive decline, which are also known in brain aging. Identification of these similarities at the molecular level offers hope for the development of new therapeutics to ameliorate all neurodegenerative diseases simultaneously. Aging is known as the most strongly associated additive factor in the pathogenesis of neurodegenerative diseases. Studies carried out so far identified several genes, which are responsible for selective degeneration of neurons in different neurodegenerative diseases. Countless efforts have been made in identifying therapeutics for neurodegenerative diseases; however, the discovery of effective therapy remains elusive. Findings made in the last two decades identified microRNAs (miRNAs) as the most potent post-transcription regulatory RNA molecule, which can condition protein levels in the cell and tissue-specific manner. Identification of miRNAs, which regulate both neurotoxicant and aging-associated degeneration of brain cells, raises the possibility that roads leading to aging and neurotoxicant induced neurodegeneration cross at some point. Identification of miRNAs, which are common to aging and neurotoxicant induced neurodegeneration, will help in understanding the complex mechanism of neurodegenerative disease development. In the future, the use of natural miRNAs in vivo in therapy will be able to tackle several issues of aging and neurodegeneration. In the present review, we have provided a summary of findings made on the role of miRNAs in neurodegeneration and explored the common link made by miRNAs between aging and neurotoxicants induced neurodegeneration.

The Mitochondria-Associated ER Membranes Are Novel Subcellular Locations Enriched for Inflammatory-Responsive MicroRNAs

The mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) are specific ER domains that contact the mitochondria and function to facilitate communication between ER and mitochondria. Disruption of contact between the mitochondria and ER is associated with a variety of pathophysiological conditions including neurodegenerative diseases. Considering the many cellular functions of MAMs, we hypothesized that MAMs play an important role in regulating microRNA (miRNA) activity linked to its unique location between mitochondria and ER. Here we present new findings from human and rat brains indicating that the MAMs are subcellular sites enriched for specific miRNAs. We employed subcellular fractionation and TaqMan® RT-qPCR miRNA analysis to quantify miRNA levels in subcellular fractions isolated from male rat brains and six human brain samples. We found that MAMs contain a substantial number of miRNAs and the profile differs significantly from that of cytosolic, mitochondria, or ER. Interestingly, MAMs are particularly enriched in inflammatory-responsive miRNAs, including miR-146a, miR-142-3p, and miR-142-5p in both human and rat brains; miR-223 MAM enrichment was observed only in human brain samples. Further, mitochondrial uncoupling or traumatic brain injury in male rats resulted in the alteration of inflammatory miRNA enrichment in the isolated subcellular fractions. These observations demonstrate that miRNAs are distributed differentially in organelles and may re-distribute between organelles and the cytosol in response to cellular stress and metabolic demands.

miR-15/107 microRNA Gene Group: Characteristics and Functional Implications in Cancer

The miR-15/107 group of microRNAs (miRNAs) encloses 10 annotated human members and is defined based on the presence of the sequence AGCAGC near the mature miRNAs’ 5′ end. Members of the miR-15/107 group expressed in humans are highly evolutionarily conserved, and seven of these miRNAs are widespread in vertebrate species. Contrary to the majority of miRNAs, which recognize complementary sequences on the 3′UTR region, some members of the miR-15/107 group are peculiarly characterized by the ability to target the coding sequence (CDS) of their target mRNAs, inhibiting translation without strongly affecting their mRNA levels. There is compelling evidence that different members of the miR-15/107 group regulate overlapping lists of mRNA targets but also show target specificity. The ubiquitously expressed miR-15/107 gene group controls several human cellular pathways, such as proliferation, angiogenesis, and lipid metabolism, and might be altered in various diseases, such as neurodegenerative diseases and cancer. Intriguingly, despite sharing the same seed sequence, different members of this family of miRNAs may behave as oncomiRs or as tumor suppressor miRNAs in the context of cancer cells. This review discusses the regulation and functional contribution of the miR-15/107 group to the control of gene expression. Moreover, we particularly focus on the contribution of specific miR-15/107 group members as tumor suppressors in breast cancer, reviewing literature reporting their ability to function as major controllers of a variety of cell pathways and to act as powerful biomarkers in this disease.

Progranulin expression induced by follicle-stimulating hormone in ovarian cancer cell lines depends on the histological subtype

Epithelial ovarian cancer (EOC) is a heterogeneous disease that can be categorized into four major histological subtypes. Its etiology remains poorly understood due mainly to this heterogeneity. Follicle-stimulating hormone (FSH) has been implicated as a risk factor in EOC and has been suggested that may influence the development of specific subtypes. In addition, FSH regulates different aspects of ovarian cancer tumorigenesis. FSH downstream target genes in EOC have not been fully identified. Progranulin (PGRN) overexpression is associated with cell proliferation, invasion, chemoresistance, and shortened overall survival in ovarian cancer. Recently, we demonstrated that PGRN expression is regulated through the PI3K signaling pathway in clear cell ovarian carcinoma (CCOC) cells. In contrast, we also demonstrated that PGRN synthesis in serous ovarian cancer (SOC) cells is regulated via PKC but not by the PI3K signaling pathway. Several studies have demonstrated that FSH induces PKC and PI3K activation. Thus, this study was to investigate the effect of FSH on PGRN production in the CCOC cell line TOV-21G as compared to the SOC cell lines SKOV3 and OVCAR3. Cultured TOV-21G, SKOV3, and OVCAR3 cells were incubated with different concentrations of FSH for 48 h. PGRN mRNA and protein expression were assessed by RT-PCR and Western blotting, while PGRN secretion was measured by ELISA. PGRN mRNA and protein expression, as well as PGRN secretion, significantly increased after FSH stimulation in TOV-21G but not in SKOV3 and OVCAR3 cells. These data indicate that FSH induces PGRN expression and secretion only in CCOC cells. Establishing specific features for CCOC could reveal potential diagnostic and therapeutic targets.

MicroRNA-107 Ameliorates Damage in a Cell Model of Alzheimer's Disease by Mediating the FGF7/FGFR2/PI3K/Akt Pathway

Alzheimer's disease (AD), the most prevalent representation of dementia, is a neurodegenerative disease resulting from the degenerative disturbance of the central nervous system. Previous studies have indicated that miR-107 is reduced in the brain neocortex of patients with AD; however, its underlying mechanism is not clear. Therefore, the objective of this study was to explore the question of whether miR-107 participates in AD development. The study confirmed that the miR-107 expression levels were dramatically decreased in patients with AD and in beta-amyloid (Aβ) (Aβ)-treated SH-SY5Y cells compared with control groups. Upregulation of miR-107 reversed the inhibitory role of Aβ on cell proliferation and viability. In addition, miR-107 upregulation also ameliorated the Aβ-induced inflammation and apoptosis of SH-SY5Y cells. Furthermore, using bioinformatic prediction, dual-luciferase reporter assay (DLRA), quantitative polymerase chain reaction (qPCR), and Western blot (WB), miR-107 was confirmed to reduce the expression level of FGF7, and it subsequently deactivated the FGFR2/PI3K/Akt pathway. Moreover, FGF7 overexpression counteracted the role of miR-107 in the viability, proliferation, inflammation, and apoptosis of Aβ-induced SH-SY5Y cells.

Suppression of miR-193a alleviates neuroinflammation and improves neurological function recovery after traumatic brain injury (TBI) in mice

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in the world, and is tightly associated with microglia-regulated neuroinflammation. However, the activation profile of microglia during the pathophysiological responses is still not fully understood. Micro-RNAs (miRs), as noncoding RNAs, are involved in the progression of TBI. In this study, we attempted to explore the effects of miR-193a on TBI using the in vivo and in vitro studies. Following experimental TBI in mice, we found that miR-193a expression was significantly up-regulated in ipsilateral cortical tissues and in the microglia/macrophages isolated from the ipsilateral cortical tissues, which was accompanied with markedly enhanced expression of pro-inflammatory factors. We then found that miR-193a hairpin inhibitor (antagomir) markedly reduced lesion volume, brain water contents and neuron death in TBI mice induced by the controlled cortical impact (CCI). In addition, cognitive dysfunction in TBI mice was markedly improved after miR-193a antagomir injection. Of note, CCI-induced activation of microglia was repressed by miR-193a inhibition, along with significantly reduced expression of neuroinflammatory markers, which were associated with the blockage of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. The anti-neuroinflammation effects of miR-193a suppression were verified in lipopolysaccharide (LPS)-incubated microglial cells transfected with miR-193a inhibitor. In contrast, LPS-induced activation of microglial cells and the expression of pro-inflammatory factors was markedly further accelerated by the transfection of miR-193a mimic. Taken together, TBI resulted in a robust neuroinflammatory response that was closely associated with the up-regulated miR-193a expression mainly in microglia/macrophages; however, miR-193a suppression significantly alleviated post-traumatic neuroinflammation and cognitive dysfunction. Therefore, miR-193a might be a promising therapeutic target for the treatment of TBI-associated neuroinflammation.

Identification of circulating microRNA signatures as potential biomarkers in the serum of elk infected with chronic wasting disease

Chronic wasting disease (CWD) is an emerging infectious prion disorder that is spreading rapidly in wild populations of cervids in North America. The risk of zoonotic transmission of CWD is as yet unclear but a high priority must be to minimize further spread of the disease. No simple diagnostic tests are available to detect CWD quickly or in live animals; therefore, easily accessible biomarkers may be useful in identifying infected animals. MicroRNAs (miRNAs) are a class of small, non-coding RNA molecules that circulate in blood and are promising biomarkers for several infectious diseases. In this study we used next-generation sequencing to characterize the serum miRNA profiles of 35 naturally infected elk that tested positive for CWD in addition to 35 elk that tested negative for CWD. A total of 21 miRNAs that are highly conserved amongst mammals were altered in abundance in sera, irrespective of hemolysis in the samples. A number of these miRNAs have previously been associated with prion diseases. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the discriminative potential of these miRNAs as biomarkers for the diagnosis of CWD. We also determined that a subgroup of 6 of these miRNAs were consistently altered in abundance in serum from hamsters experimentally infected with scrapie. This suggests that common miRNA candidate biomarkers could be selected for prion diseases in multiple species. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses pointed to a strong correlation for 3 of these miRNAs, miR-148a-3p, miR-186-5p, miR-30e-3p, with prion disease.

Altered microRNA 5692b and microRNA let-7d expression levels in children and adolescents with attention deficit hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder. Its etiology is not clearly understood yet, but neurobiological, genetic and environmental factors are shown to play a role. The relationship between ADHD and miRNAs has been studied quite recently, and few studies have been conducted up to now. In this study, peripheral blood expression levels of miR-5692b, miR-let-7d, miR-124-3p, miR-4447 and miR-107 of 30 children and adolescents with combined type ADHD were compared to 30 healthy controls to understand the roles of these miRNAs in the ADHD etiopathogenesis. Compared to controls, levels of miR-5692b (p = 0.006) were found higher and levels of miR-let-7d (p = 0.017) were found lower in the ADHD group. There was no significant difference in terms of miR-124-3p, miR-4447, and miR-107 levels between the groups. In conclusion, our findings support other studies suggesting the importance of miRNAs in the pathogenesis of ADHD. Regarding the regulatory role of miRNAs in gene regulation, their contribution to etiopathogenesis and heterogeneity of ADHD should be investigated further.

Impact of Lipotoxicity on Tissue "Cross Talk" and Metabolic Regulation

Obesity-associated comorbidities include non-alcoholic fatty liver disease, Type 2 diabetes, and cardiovascular disease. These diseases are associated with accumulation of lipids in non-adipose tissues, which can impact many intracellular cellular signaling pathways and functions that have been broadly defined as "lipotoxic." This review moves beyond understanding intracellular lipotoxic outcomes and outlines the consequences of lipotoxicity on protein secretion and inter-tissue "cross talk," and the impact this exerts on systemic metabolism.

Upregulation of microRNA-140-3p inhibits epithelial-mesenchymal transition, invasion, and metastasis of hepatocellular carcinoma through inactivation of the MAPK signaling pathway by targeting GRN

Invasion and metastasis in hepatocellular carcinoma (HCC) results in poor prognosis. Human intervention in these pathological processes may benefit the treatment of HCC. The aim of the present study is to elucidate the mechanism of miR-140-3p affecting epithelial-mesenchymal transition (EMT), invasion, and metastasis in HCC. Microarray analysis was performed for differentially expressed genes screening. The target relationship between miR-140-3p and GRN was analyzed. Small interfering RNA (siRNA) against granulin (GRN) was synthesized. EMT markers were detected, and invasion and migration were evaluated in HCC cells introduced with a miR-140-3p inhibitor or mimic, or siRNA against GRN. A mechanistic investigation was conducted for the determination of mitogen-activated protein kinase (MAPK) signaling pathway-related genes and EMT markers (E-cadherin, N-cadherin, and Vimentin). GRN was highlighted as an upregulated gene in HCC. GRN was a target gene of miR-140-3p. Elevation of miR-140-3p or inhibition of GRN restrained the EMT process and suppressed the HCC cell migration and invasion. HCC cells treated with the miR-140-3p mimic or siRNA-GRN exhibited decreased GRN expression and downregulated the expressions of the MAPK signaling pathway-related genes, N-cadherin, and Vimentin but upregulated the expression of E-cadherin. GRN silencing can reverse the activation of the MAPK signaling pathway and induction of EMT mediated by miR-140-3p inhibition. Taken together, the results show that miR-140-3p confers suppression of the MAPK signaling pathway by targeting GRN, thus inhibiting EMT, invasion, and metastasis in HCC.

Identification and Expression of Neurotrophin-6 in the Brain of Nothobranchius furzeri: One More Piece in Neurotrophin Research

Neurotrophins contribute to the complexity of vertebrate nervous system, being involved in cognition and memory. Abnormalities associated with neurotrophin synthesis may lead to neuropathies, neurodegenerative disorders and age-associated cognitive decline. The genome of teleost fishes contains homologs of some mammalian neurotrophins as well as a gene coding for an additional neurotrophin (NT-6). In this study, we characterized this specific neurotrophin in the short-lived fish Nothobranchius furzeri, a relatively new model for aging studies. Thus, we report herein for the first time the age-related expression of a neurotrophin in a non-mammalian vertebrate. Interestingly, we found comparable expression levels of NT-6 in the brain of both young and old animals. More in detail, we used a locked nucleic acid probe and a riboprobe to investigate the neuroanatomical distribution of NT-6 mRNA revealing a significant expression of the neurotrophin in neurons of the forebrain (olfactory bulbs, dorsal and ventral telencephalon, and several diencephalic nuclei), midbrain (optic tectum, longitudinal tori, and semicircular tori), and hindbrain (valvula and body of cerebellum, reticular formation and octavolateral area of medulla oblongata). By combining in situ hybridization and immunohistochemistry, we showed that NT-6 mRNA is synthesized in mature neurons. These results contribute to better understanding the evolutionary history of neurotrophins in vertebrates, and their role in the adult brain.

MicroRNAs in Neuroinflammation: Implications in Disease Pathogenesis, Biomarker Discovery and Therapeutic Applications

The central nervous system can respond to threat via the induction of an inflammatory response. Under normal circumstances this response is tightly controlled, however uncontrolled neuroinflammation is a hallmark of many neurological disorders. MicroRNAs are small non-coding RNA molecules that are important for regulating many cellular processes. The ability of microRNAs to modulate inflammatory signaling is an area of ongoing research, which has gained much attention in recent years. MicroRNAs may either promote or restrict inflammatory signaling, and either exacerbate or ameliorate the pathological consequences of excessive neuroinflammation. The aim of this review is to summarize the mode of regulation for several important and well-studied microRNAs in the context of neuroinflammation, including miR-155, miR-146a, miR-124, miR-21 and let-7. Furthermore, the pathological consequences of miRNA deregulation during disorders that feature neuroinflammation are discussed, including Multiple Sclerosis, Alzheimer’s disease, Parkinson’s disease, Prion diseases, Japanese encephalitis, Herpes encephalitis, ischemic stroke and traumatic brain injury. There has also been considerable interest in the use of altered microRNA signatures as biomarkers for these disorders. The ability to modulate microRNA expression may even serve as the basis for future therapeutic strategies to help treat pathological neuroinflammation.

A Review of MicroRNA Biomarkers in Traumatic Brain Injury

There is growing public concern surrounding traumatic brain injury (TBI). TBI can cause significant morbidity, and the long-term sequelae are poorly understood. TBI diagnosis and management rely on patient-reported symptoms and subjective clinical assessment. There are no biologic tools to detect mild TBI or to track brain recovery. Emerging evidence suggests that microRNAs (miRNAs) may provide information about the injured brain. These tiny epigenetic molecules are expressed throughout the body. However, they are particularly important in neurons, can cross the blood-brain barrier, and are securely transported from cell to cell, where they regulate gene expression. miRNA levels may identify patients with TBI and predict symptom duration. This review synthesizes miRNA findings from 14 human studies. We distill more than 291 miRNAs to 17 biomarker candidates that overlap across multiple studies and multiple biofluids. The goal of this review is to establish a collective understanding of miRNA biology in TBI and identify clinical priorities for future investigations of this promising biomarker.

Down-Regulation of Mir-107 Worsen Spatial Memory by Suppressing SYK Expression and Inactivating NF-ΚB Signaling Pathway

Background:

Alzheimer’s Disease (AD) is a chronic progressive neurodegenerative disorder in a central nervous system seen.

Objective:

We aimed to study the miR-107 in Alzheimer's Disease (AD) pathology through regulating SYK and NF-κB signaling pathway. </P><P> Method: Bioinformatics analysis was performed to screen NF-κB signaling pathway and differentially expressed genes. The target relationship between miR-107 and SYK was verified by dual luciferase assay. QRT-PCR and western blot analysis were used to verify the expression level of miR-107, SYK and NF- κB signaling pathway related proteins of hippocampus primary neurons. BAY61-3606 and BAY11-7082 were purchased for functional examination. Morris water maze tests were performed to access spatial memory of AD mice with SYK and NF-κB signaling pathway inhibition. Fluorescence microscope dyeing experiment investigated the neurons nuclear form and apoptosis.

Results:

MiR-107 was lowly expressed while SYK was highly expressed in Tg19959 mouse model. Luciferase Assay confirmed the target relationship in miR-107 and SYK. With the inhibition of miR-107, SYK was up-regulated and the increase of p-p65 and the decrease of p-IκB-α suggested that NF-κB signaling pathway was activated in vitro. Morris water maze test indicated that the spatial memory of Tg19959 mice was increased with the treatment. The result of DAPI staining indicated that the inhibition of SYK or NF-κB signaling pathway reduced the apoptosis of Tg19959 mice neuron cell.

Conclusion:

MiR-107 exerts its effects through suppression of the NF-κB signaling pathway and SYK, the inhibition of SYK and NF-κB signaling pathway can improve spatial memory and suppress cell apoptosis.

miR-107 modulates chondrocyte proliferation, apoptosis, and extracellular matrix synthesis by targeting PTEN

BACKGROUND

Osteoarthritis (OA) is a common chronic degenerative disease, and the chondrocyte is reported to be a key player in OA progression. Increasing evidence has verified the regulatory role of miRNAs in OA. However, the function and underlying mechanism of miR-107 in cartilage function are still not clarified.

METHODS

Abundance of miR-107 and PTEN mRNA were detected by qRT-PCR. Relative protein levels of PTEN, Bcl-2, Bax, Caspase-3, aggrecan, collagen II, MMP-13, and MMP-9 were measured by western blotting (WB). A biological web server Targetscan was used to predict the putative binding sites between miR-107 and PTEN, and luciferase reporter assay was employed to further verify the true interplay between them. Cell proliferative or apoptotic activity was assessed by MTT or flow cytometry (FCM) analysis.

RESULTS

miR-107 was downregulated and PTEN was upregulated in OA tissues. PTEN could be negatively regulated by miR-107 by targeted interaction. Interference of PTEN induced proliferation of C28/I2 cells, but inhibited cell apoptosis. Restoration of PTEN reversed miR-107-stimulated cell proliferation and miR-107-inhibited apoptosis in C28/I2 cells. Furthermore, enforced abundance of miR-107 promoted the expressions of aggrecan and collagen II protein, while it attenuated MMP-13 and MMP-9 expression in C28/I2 cells, which was overturned by PTEN restoration.

CONCLUSION

miR-107 induced chondrocyte growth and ameliorated cartilage degradation by targeting to PTEN, providing a potential therapeutic target for OA.

Retracted Article: Berberine alleviates amyloid beta-induced injury in Alzheimer's disease by miR-107/ZNF217

Berberine plays a neuroprotective role in neurodegenerative disorders, including Alzheimer's disease (AD). However, the underlying mechanism by which berberine inhibits AD progression remains largely unclear. The AD model was established using PC12 cells after treatment of amyloid beta (Aβ)_25-35. Cells were transfected with microRNA (miRNA)-107 mimic, inhibitor, zinc finger protein 217 (ZNF217) overexpression or corresponding negative controls. Cell viability, apoptosis and inflammatory cytokine secretion were measured by MTT, flow cytometry or enzyme linked immunosorbent assay, respectively. The expressions of miR-107, ZNF217 and phosphorylated tau (p-Tau) were detected by quantitative real-time polymerase chain reaction or Western blot. The association between miR-107 and ZNF217 was explored by luciferase reporter assay and RNA immunoprecipitation. Berberine attenuated Aβ_25-35-induced viability suppression in PC12 cells. Moreover, berberine inhibited the Aβ_25-35-induced increase of inflammatory cytokine expression, apoptosis and p-Tau level in PC12 cells. miR-107 expression was reduced in Aβ_25-35-treated PC12 cells and its overexpression alleviated Aβ_25-35-induced injury, which was further weakened by combination with berberine. ZNF217 was a target of miR-107 and its addition reversed miR-107-mediated inhibition of inflammatory injury, apoptosis and phosphorylation of tau. Besides, ZNF217 protein level was decreased by berberine via regulating miR-107 in Aβ_25-35-treated PC12 cells. Berberine protected against Aβ_25-35-induced inflammatory injury, apoptosis and phosphorylation of tau by regulating miR-107 and ZNF217, indicating berberine as a promising neuroprotective agent for therapeutics of AD.

Berberine plays a neuroprotective role in neurodegenerative disorders, including Alzheimer's disease (AD).

Non-coding RNA influences in dementia

Dementia is a complex clinical syndrome characterised by progressive decline in cognitive function. It usually presents itself as impairment in memory, loss of judgement, abstract thinking and other disturbances that are severe enough to interfere with activities of daily living. It has long been considered as one of the major challenges at present posing an ever-increasing demand on global health and social care systems. Of all the different forms of dementia, Alzheimer's disease (AD) is the most common. The term non-coding RNA (ncRNA) refers to RNA sequences which do not have the ability to be translated into proteins and therefore mainly fall within the realm of the recently acknowledged ‘dark matter’ of the genome. This genomic dark matter encompasses a whole spectrum of differing ncRNA families such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), PIWI-interacting RNAs (piRNAs), transfer RNAs (tRNAs), small nuclear RNAs (snoRNAs) and circular RNAs (circRNAs), to name but a few. Consequently, due to the widespread influences of miRNAs and lncRNAs across all disease pathways, it is of critical importance for researchers in the field of dementia to focus their attention on possible ncRNA-induced pathogeneses, with the ultimate goal of identifying novel diagnostic procedures and drug targets, together with the development of novel therapies to control such a devastating mental condition in the patient population.

miR-34b-5p inhibition attenuates lung inflammation and apoptosis in an LPS-induced acute lung injury mouse model by targeting progranulin

Inflammation and apoptosis play important roles in the initiation and progression of acute lung injury (ALI). Our previous study has shown that progranulin (PGRN) exerts lung protective effects during LPS-induced ALI. Here, we have investigated the potential roles of PGRN-targeting microRNAs (miRNAs) in regulating inflammation and apoptosis in ALI and have highlighted the important role of PGRN. LPS-induced lung injury and the protective roles of PGRN in ALI were first confirmed. The function of miR-34b-5p in ALI was determined by transfection of a miR-34b-5p mimic or inhibitor in intro and in vivo. The PGRN level gradually increased and subsequently significantly decreased, reaching its lowest value by 24 hr; PGRN was still elevated compared to the control. The change was accompanied by a release of inflammatory mediators and accumulation of inflammatory cells in the lungs. Using bioinformatics analysis and RT-PCR, we demonstrated that, among 12 putative miRNAs, the kinetics of the miR-34b-5p levels were closely associated with PGRN expression in the lung homogenates. The gain- and loss-of-function analysis, dual-luciferase reporter assays, and rescue experiments confirmed that PGRN was the functional target of miR-34b-5p. Intravenous injection of miR-34b-5p antagomir in vivo significantly inhibited miR-34b-5p up-regulation, reduced inflammatory cytokine release, decreased alveolar epithelial cell apoptosis, attenuated lung inflammation, and improved survival by targeting PGRN during ALI. miR-34b-5p knockdown attenuates lung inflammation and apoptosis in an LPS-induced ALI mouse model by targeting PGRN. This study shows that miR-34b-5p and PGRN may be potential targets for ALI treatments.

Salivary MicroRNAs: Diagnostic Markers of Mild Traumatic Brain Injury in Contact-Sport

Concussion is difficult to diagnose, particularly when symptoms are atypical or late in presenting. An accurate and timely initial assessment is crucial for clinical management. Cerebral spinal fluid (CSF) and blood markers of traumatic brain injury show promising results but their clinical applicability in concussion has significant limitations. In the study, we explored saliva as a new source of biomarkers of concussion. Saliva samples of concussed players were collected after 48-72 h from concussion and analyzed by high-throughput technologies. A discovery group of 10 concussed rugby professional and semiprofessional athletes and 10 non-concussed matched controls was used for the analysis of 92 inflammatory proteins by the Proseek-Multiplex-Inflammation technology. In addition, saliva samples of 6 concussed and 6 non-concussed athletes were used to screen 800 human microRNAs (miRNAs) by the Nanostring Technology. The results were then validated by RT-qPCR in an enlarged cohort (validation group) comprising 22 concussed athletes. Results showed, no significant variations of the 65 inflammatory proteins detected in saliva between groups but 5 microRNAs, miR-27b-3p (p = 0.016), let-7i-5p (p = 0.001), miR-142-3p (p = 0.008), miR-107 (p = 0.028), miR-135b-5p (p = 0.017) significantly upregulated in concussed athletes. Univariate ROC curve analysis showed that the differentially expressed miRNAs could be considered good classifiers of concussion. Further analyses showed significant correlation between these microRNAs and Reaction Time component of the ImPACT concussion assessment tool. In addition, biocomputation analysis predicted the involvement of these microRNAs in important biological processes that might be related to trauma, such as response to hypoxia, cell death, neurogenesis, axon repair and myelination. Ease of access and non-invasiveness of saliva samples make these biomarkers particularly suitable for concussion assessment.

Pleiotropic functions of miR107 in cancer networks

MicroRNAs are short regulatory RNAs that posttranscriptionally modulate gene expression and thus play crucial roles in controlling cancer-onset, growth, and progression processes. miR107, a highly conserved microRNA that maps to intron 5 of the PANK1 gene, contributes to the regulation of normal and tumor biological processes. Studies have reported that miR107 has oncogenic or tumor-suppressor functions in different human tumors. The pleiotropic functions of miR107 in various cancers are achieved via its targeting different genes that are involved in tumor proliferation, invasiveness, metastasis, angiogenesis, and chemotherapy-response pathways. The carcinogenicity or cancer-suppressor effects of miR107 occur in a tissue- and cell-specific manner, and the expression level of miR107 can be affected by various factors, including epigenetic and genetic factors, treatment exposure, and daily diet. A comprehensive analysis of the current literature suggests that miR107 functions as a central element in the regulation of cancer networks and can be used as a potential diagnostic and prognostic biomarker and drug target for therapeutic intervention.

Expression of ID4 protein in breast cancer cells induces reprogramming of tumour-associated macrophages

Background

As crucial regulators of the immune response against pathogens, macrophages have been extensively shown also to be important players in several diseases, including cancer. Specifically, breast cancer macrophages tightly control the angiogenic switch and progression to malignancy. ID4, a member of the ID (inhibitors of differentiation) family of proteins, is associated with a stem-like phenotype and poor prognosis in basal-like breast cancer. Moreover, ID4 favours angiogenesis by enhancing the expression of pro-angiogenic cytokines interleukin-8, CXCL1 and vascular endothelial growth factor. In the present study, we investigated whether ID4 protein exerts its pro-angiogenic function while also modulating the activity of tumour-associated macrophages in breast cancer.

Methods

We performed IHC analysis of ID4 protein and macrophage marker CD68 in a triple-negative breast cancer series. Next, we used cell migration assays to evaluate the effect of ID4 expression modulation in breast cancer cells on the motility of co-cultured macrophages. The analysis of breast cancer gene expression data repositories allowed us to evaluate the ability of ID4 to predict survival in subsets of tumours showing high or low macrophage infiltration. By culturing macrophages in conditioned media obtained from breast cancer cells in which ID4 expression was modulated by overexpression or depletion, we identified changes in the expression of ID4-dependent angiogenesis-related transcripts and microRNAs (miRNAs, miRs) in macrophages by RT-qPCR.

Results

We determined that ID4 and macrophage marker CD68 protein expression were significantly associated in a series of triple-negative breast tumours. Interestingly, ID4 messenger RNA (mRNA) levels robustly predicted survival, specifically in the subset of tumours showing high macrophage infiltration. In vitro and in vivo migration assays demonstrated that expression of ID4 in breast cancer cells stimulates macrophage motility. At the molecular level, ID4 protein expression in breast cancer cells controls, through paracrine signalling, the activation of an angiogenic programme in macrophages. This programme includes both the increase of angiogenesis-related mRNAs and the decrease of members of the anti-angiogenic miR-15b/107 group. Intriguingly, these miRNAs control the expression of the cytokine granulin, whose enhanced expression in macrophages confers increased angiogenic potential.

Conclusions

These results uncover a key role for ID4 in dictating the behaviour of tumour-associated macrophages in breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0990-2) contains supplementary material, which is available to authorized users.