Serum miR-30c-5p is a potential biomarker for multiple system atrophy

Diagnosing multiple system atrophy: current clinical guidance and emerging molecular biomarkers

Multiple system atrophy (MSA) is a rare and progressive neurodegenerative disorder characterized by motor and autonomic dysfunction. Accurate and early diagnosis of MSA is challenging due to its clinical similarity with other neurodegenerative disorders, such as Parkinson's disease and atypical parkinsonian disorders. Currently, MSA diagnosis is based on clinical criteria drawing from the patient's symptoms, lack of response to levodopa therapy, neuroimaging studies, and exclusion of other diseases. However, these methods have limitations in sensitivity and specificity. Recent advances in molecular biomarker research, such as α-synuclein protein amplification assays (RT-QuIC) and other biomarkers in cerebrospinal fluid and blood, have shown promise in improving the diagnosis of MSA. Additionally, these biomarkers could also serve as targets for developing disease-modifying therapies and monitoring treatment response. In this review, we provide an overview of the clinical syndrome of MSA and discuss the current diagnostic criteria, limitations of current diagnostic methods, and emerging molecular biomarkers that offer hope for improving the accuracy and early detection of MSA.

MicroRNAs in Parkinson's disease: a systematic review and diagnostic accuracy meta-analysis

Current clinical tests for Parkinson's disease (PD) provide insufficient diagnostic accuracy leading to an urgent need for improved diagnostic biomarkers. As microRNAs (miRNAs) are promising biomarkers of various diseases, including PD, this systematic review and meta-analysis aimed to assess the diagnostic accuracy of biofluid miRNAs in PD. All studies reporting data on miRNAs expression in PD patients compared to controls were included. Gene targets and significant pathways associated with miRNAs expressed in more than 3 biofluid studies with the same direction of change were analyzed using target prediction and enrichment analysis. A bivariate model was used to calculate sensitivity, specificity, likelihood ratios, and diagnostic odds ratio. While miR-24-3p and miR-214-3p were the most reported miRNA (7 each), miR-331-5p was found to be consistently up regulated in 4 different biofluids. Importantly, miR-19b-3p, miR-24-3p, miR-146a-5p, and miR-221-3p were reported in multiple studies without conflicting directions of change in serum and bioinformatic analysis found the targets of these miRNAs to be associated with pathways important in PD pathology. Of the 102 studies from the systematic review, 15 studies reported sensitivity and specificity data on combinations of miRNAs and were pooled for meta-analysis. Studies (17) reporting sensitivity and specificity data on single microRNA were pooled in a separate meta-analysis. Meta-analysis of the combinations of miRNAs (15 studies) showed that biofluid miRNAs can discriminate between PD patients and controls with good diagnostic accuracy (sensitivity = 0.82, 95% CI 0.76-0.87; specificity = 0.80, 95% CI 0.74-0.84; AUC = 0.87, 95% CI 0.83-0.89). However, we found multiple studies included more males with PD than any other group therefore possibly introducing a sex-related selection bias. Overall, our study captures key miRNAs which may represent a point of focus for future studies and the development of diagnostic panels whilst also highlighting the importance of appropriate study design to develop representative biomarker panels for the diagnosis of PD.

Multidimensional biomarkers for multiple system atrophy: an update and future directions

Multiple system atrophy (MSA) is a fatal progressive neurodegenerative disease. Biomarkers are urgently required for MSA to improve the diagnostic and prognostic accuracy in clinic and facilitate the development and monitoring of disease-modifying therapies. In recent years, significant research efforts have been made in exploring multidimensional biomarkers for MSA. However, currently few biomarkers are available in clinic. In this review, we systematically summarize the latest advances in multidimensional biomarkers for MSA, including biomarkers in fluids, tissues and gut microbiota as well as imaging biomarkers. Future directions for exploration of novel biomarkers and promotion of implementation in clinic are also discussed.

Inflammation in multiple system atrophy

Misfolding protein aggregation inside or outside cells is the major pathological hallmark of several neurodegenerative diseases. Among proteinopathies are neurodegenerative diseases with atypical Parkinsonism and an accumulation of insoluble fibrillary alpha-synuclein (synucleinopathies) or hyperphosphorylated tau protein fragments (tauopathies). As there are no therapies available to slow or halt the progression of these disea ses, targeting the inflammatory process is a promising approach. The inflammatory biomarkers could also help in the differential diagnosis of Parkinsonian syndromes. Here, we review inflammation's role in multiple systems atrophy pathogenesis, diagnosis, and treatment.

Gender differences in microRNA expression in levodopa-naive PD patients

Gender is an important factor influencing epidemiological and clinical features of Parkinson's disease (PD). We aimed to evaluate gender differences in the expression of a panel of miRNAs (miR-34a-5p, miR-146a, miR-155, miR-29a, miR-106a) possibly involved in the pathophysiology or progression of disease. Serum samples were obtained from 104 PD patients (58 men and 46 women) never treated with levodopa. We measured levels of miRNAs using quantitative PCR. Correlations between miRNA expression and clinical data were assessed using the Spearman's correlation test. We used STRING to evaluate co-expression relationship among target genes. MiR-34a-5p was significantly upregulated in PD male patients compared to PD female patients (fc: 1.62; p < 0.0001). No correlation was found with age, BMI, and disease severity, assessed by UPDRS III scale, in male and female patients. MiR-146a-5p was significantly upregulated in female as compared to male patients (fc: 3.44; p < 0.0001) and a significant correlation was also observed between disease duration and mir-146a-5p. No differences were found in the expression of miR-29a, miR-106a-5p and miR-155 between genders. Predicted target genes for miR-34a-5p and miR-146-5p and protein interactions in biological processes were reported. Our study supports the hypothesis that there are gender-specific differences in serum miRNAs expression in PD patients. Follow-up of this cohort is needed to understand if these differences may affect disease progression and response to treatment.

State of the Art of microRNAs Signatures as Biomarkers and Therapeutic Targets in Parkinson's and Alzheimer's Diseases: A Systematic Review and Meta-Analysis

Identifying target microRNAs (miRNAs) might serve as a basis for developing advanced therapies for Parkinson's disease (PD) and Alzheimer's disease. This review aims to identify the main therapeutic targets of miRNAs that can potentially act in Parkinson's and Alzheimer's diseases. The publication research was conducted from May 2021 to March 2022, selected from Scopus, PubMed, Embase, OVID, Science Direct, LILACS, and EBSCO. A total of 25 studies were selected from 1549 studies evaluated. The total number of miRNAs as therapeutic targets evidenced was 90 for AD and 54 for PD. An average detection accuracy of above 84% for the miRNAs was observed in the selected studies of AD and PD. The major signatures were miR-26b-5p, miR-615-3p, miR-4722-5p, miR23a-3p, and miR-27b-3p for AD and miR-374a-5p for PD. Six miRNAs of intersection were found between AD and PD. This article identified the main microRNAs as selective biomarkers for diagnosing PD and AD and therapeutic targets through a systematic review and meta-analysis. This article can act as a microRNA guideline for laboratory research and pharmaceutical industries for treating Alzheimer's and Parkinson's diseases and offers the opportunity to evaluate therapeutic interventions earlier in the disease process.

Emerging Role of MicroRNA-30c in Neurological Disorders

MicroRNAs (miRNAs or miRs) are a class of small non-coding RNAs that negatively regulate the expression of target genes by interacting with 3' untranslated regions of target mRNAs to induce mRNA degradation and translational repression. The miR-30 family members are involved in the development of many tissues and organs and participate in the pathogenesis of human diseases. As a key member of the miR-30 family, miR-30c has been implicated in neurological disorders such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, and stroke. Mechanistically, miR-30c may act as a multi-functional regulator of different pathogenic processes such as autophagy, apoptosis, endoplasmic reticulum stress, inflammation, oxidative stress, thrombosis, and neurovascular function, thereby contributing to different disease states. Here, we review and discuss the biogenesis, gene regulation, and the role and mechanisms of action of miR-30c in several neurological disorders and therapeutic potential in clinics.

miRNA and antisense oligonucleotide-based α-synuclein targeting as disease-modifying therapeutics in Parkinson's disease

α-synuclein is the synaptic protein majorly involved in neuronal dysfunction and death and it is well known for the last two decades as a hallmark of Parkinson's disease. Alpha-synuclein is involved in neurodegeneration mediated through various neurotoxic pathways, majorly including autophagy or lysosomal dysregulation, mitochondrial disruption, synaptic dysfunction, and oxidative stress. Moreover, the alpha-synuclein aggregation has been associated with the development of several neurodegenerative conditions such as various forms of Parkinson's disease. The recent discovery in oligonucleotide chemistry has developed potential alpha-synuclein targeting molecules for the treatment of neurodegenerative diseases. The present review article focuses on recent advances in the applications of oligonucleotides acting via alpha-synuclein targeting mechanisms and their implication in combating Parkinson's disease. Moreover, the article emphasizes the potential of miRNAs, and antisense oligonucleotides and the challenges associated with their use in the therapeutical management of Parkinson's disease.

MicroRNA Expression Profile Changes in the Leukocytes of Parkinson’s Disease Patients

Parkinson’s disease (PD) is one of the most common movement disorders. It is primarily diagnosed clinically. A correct diagnosis of PD in its early stages is important for the development of a pathogenic treatment, which necessitates a search for potential biomarkers of the disease. We evaluated the diagnostic value of several microRNAs and their relationship with the clinical characteristics of PD. The study included 70 PD patients and 40 healthy volunteers. We analyzed the expression of 15 microRNAs in blood leukocytes, which were selected based on literature data and modern concepts of molecular PD pathogenesis. All patients were evaluated using the Hoehn and Yahr scale, UPDRS, NMSQ, and PDQ-39. The data analysis revealed a statistically significant increase in the expression of miR-7-5p, miR-29c-3p, and miR-185-5p and a statistically significant decrease in the expression of miR-29a-3p and miR-30c-1-5p in leukocytes in PD. However, the altered microRNA profile was shown to have a moderate diagnostic value for PD diagnosis. MicroRNA expression changes were associated with the motor and non-motor phenotypic features of PD and administration of anti-Parkinson’s drugs. Also, a relationship between some of the microRNAs studied and the duration and severity of PD was found, which may potentially be used to monitor disease progression.

Serum miR-96-5P and miR-339-5P Are Potential Biomarkers for Multiple System Atrophy and Parkinson's Disease

Parkinson's disease (PD) and Multiple System Atrophy (MSA) are progressive neurodegenerative diseases with overlap of symptoms in early stages of disease. No reliable biomarker exists and the diagnosis is mainly based on clinical features. Several studies suggest that miRNAs are involved in PD and MSA pathogenesis. Our goal was to study two serum circulating microRNAs (miR-96-5p and miR-339-5p) as novel biomarkers for the differential diagnosis between PD and MSA. Serum samples were obtained from 51 PD patients, 52 MSA patients and 56 healthy controls (HC). We measured levels of miRNAs using quantitative PCR and compared the levels of miR-96-5p and miR-339-5p among PD, MSA and HC groups using a one-way analysis of variance. Correlations between miRNA expression and clinical data were calculated using Pearson's rho test. We used the miRTarBase to detect miRNA targets and STRING to evaluate co-expression relationship among target genes. MiR-96-5p was significantly increased in MSA patients compared with HC (Fold change (fc): 3.6; p = 0.0001) while it was decreased in PD patients compared with HC (Fold change: 4; p = 0.0002). Higher miR-96-5P levels were directly related to longer disease duration in MSA patients. We observed a significant increase of miR-339-5p in MSA patients compared with PD patients (fc: 2.5; p = 0.00013). miR-339-5p was increased in MSA patients compared with HC (fc: 2.4; p = 0.002). We identified 32 target genes of miR-96-5p and miR-339-5p, some of which are involved in neurodegenerative diseases. The study of those miRNAs could be useful to identify non-invasive biomarkers for early differential diagnosis between PD and MSA.

Functional roles of non-coding RNAs in atrophy

Atrophy is defined as a reduction in cell, organ, or tissue size after reaching their normal mature sizes because of loss of organelles, cytoplasmic compartments, and proteins. This process is also involved in the pathogenesis of human disorders. Inadequate nourishment, poor circulation, inadequate hormonal support, defects in nerve supply of the tissue, disproportionate induction of apoptosis in the tissue, and absence of exercise are some underlying causes of atrophy. Recently, several non-coding RNAs (ncRNAs) have been identified that regulate atrophy, thus participating in the pathobiology of related disorders such as neurodegenerative/ neuromuscular diseases, age-related muscle atrophy, and cardiac tissue atrophy. In the current review, we have focused on two classes of ncRNAs namely long ncRNAs (lncRNAs) and microRNAs (miRNAs) to unravel their participation in atrophy-associated disorders.

MiR-30c-5p/ATG5 Axis Regulates the Progression of Parkinson's Disease

Serum miR-30c-5p correlates with Parkinson’s disease (PD), yet its role has not been illustrated. This research analyzed the function of miR-30c-5p in PD. The behavioral evaluation was performed on MPTP-treated PD mice transfected with miR-30c-5p agomiR, antagomiR, siATG5, or 3-MA (an autophagy inhibitor). Oxidative stress-related factors, miR-30c-5p, and apoptosis- and autophagy-associated proteins in brain tissues or cells were determined by molecular experiments. Tyrosine hydroxylase (TH) and dopamine metabolic markers were detected using immunofluorescence and Diode Array Detector (DAD), respectively. Effects of miR-30c-5p and its target gene Autophagy-related gene (ATG) 5 protein (ATG5) on MPP+-treated SH-SY5Y cells were determined through a series of molecular experiments. MiR-30c-5p was upregulated but ATG5 was downregulated in PD mice. MiR-30c-5p antagomiR attenuated the decrease of ATG5 in PD mice. MiR-30c-5p antagomiR partly alleviated the behavioral symptoms and inhibited the increases of malondialdehyde (MDA), catalase (CAT), and SOD in PD mice. The levels of Bcl-2, dopamine, dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), TH, and LC3 II were downregulated in PD mice, while Bax, cleaved caspase-3, P62, and LC3 I were upregulated. However, miR-30c-5p antagomiR partly reversed the levels of these factors in PD mice. 3-MA could block the effects of miR-30c-5p antagomiR on PD mice. MiR-30c-5p antagomiR attenuated apoptosis and induced autophagy in brain tissues of MPTP-treated mice by targeting ATG5. In vitro assay results also showed that silence of ATG5 reduced the protective effect of miR-30c-5p downregulation on the cells. MiR-30c-5p regulates the progression of Parkinson’s disease through attenuating ATG5-inhibited apoptosis and -induced autophagy.

MicroRNAs, Parkinson's Disease, and Diabetes Mellitus

Parkinson’s disease (PD) is a neurodegenerative disorder that affects 1% of the population over the age of 60. Diabetes Mellitus (DM) is a metabolic disorder that affects approximately 25% of adults over the age of 60. Recent studies showed that DM increases the risk of developing PD. The link between DM and PD has been discussed in the literature in relation to different mechanisms including mitochondrial dysfunction, oxidative stress, and protein aggregation. In this paper, we review the common microRNA (miRNA) biomarkers of both diseases. miRNAs play an important role in cell differentiation, development, the regulation of the cell cycle, and apoptosis. They are also involved in the pathology of many diseases. miRNAs can mediate the insulin pathway and glucose absorption. miRNAs can also regulate PD-related genes. Therefore, exploring the common miRNA biomarkers of both PD and DM can shed a light on how these two diseases are correlated, and targeting miRNAs is a potential therapeutic opportunity for both diseases.

MiR-30c-5p/ROCK2 axis regulates cell proliferation, apoptosis and EMT via the PI3K/AKT signaling pathway in HG-induced HK-2 cells

Diabetic nephropathy (DN) is one of the most common complications of diabetes mellitus. Increasing evidence suggests that microRNA-30c-5p (miR-30c-5p) participates in the pathogenesis of DN, but the mechanism has not been clearly understood. Therefore, this study aimed to investigate the biological role of miR-30c-5p in human DN progression in vitro. Compared with the controls, DN tissues and high glucose-induced HK-2 cells had significantly reduced miR-30c-5p levels, while ROCK2 expression was prominently elevated. Additionally, the miR-30c-5p mimic distinctly facilitated cell proliferation and blocked cell apoptosis and epithelial–mesenchymal transition (EMT). However, ROCK2 was a target gene of miR-30c-5p, and the effects of miR-30c-5p mimic on cell proliferation, apoptosis and EMT were reversed by ROCK2 upregulation in vitro. Furthermore, the pathogenesis of DN was regulated by the miR-30c-5p/ROCK2 axis via the PI3K/AKT pathway. MiR-30c-5p regulating cell proliferation, apoptosis and EMT through targeting ROCK2 via the PI3K/AKT pathway provides the novel potential target for clinical treatment of DN.

Mini-Review: The MSA transcriptome

Multiple system atrophy (MSA) is an atypical parkinsonism that rapidly affects motor ability and autonomic function, leaving patients wheelchair-bound and dependent for daily activities in 3-5 years. Differential diagnosis is challenging as cases may resemble Parkinson's disease or other ataxic syndromes depending on the clinical variant (MSA-P or MSA-C), especially in early stages. There are limited symptomatic treatments and no disease-modifying therapies. Pathologically, alpha-synuclein aggregates are found in glial cytoplasmic inclusions, among other proteins, as well as in neurons. The molecular pathogenesis of the disease, however, is widely unknown. Transcriptomic studies in MSA have tried to unravel the pathological mechanisms involved in the disease. Several biological and molecular processes have been described in the literature that associate disease pathogenesis with inflammation, mitochondrial, and autophagy related dysfunctions, as well as prion disease and Alzheimer disease associated pathways. These reports have also registered several differential diagnostic biomarker candidates. However, cross-validation between studies, in general, is poor, making clinical applicability and data reliability very challenging. This review will go over the main transcriptomic studies done in MSA, reporting on the most significant transcriptive and post-transcriptive changes described, and focusing on the main consensual findings.

MicroRNA: A Key Player for the Interplay of Circadian Rhythm Abnormalities, Sleep Disorders and Neurodegenerative Diseases

Circadian rhythms are endogenous 24-h oscillators that regulate the sleep/wake cycles and the timing of biological systems to optimize physiology and behavior for the environmental day/night cycles. The systems are basically generated by transcription-translation feedback loops combined with post-transcriptional and post-translational modification. Recently, evidence is emerging that additional non-coding RNA-based mechanisms are also required to maintain proper clock function. MicroRNA is an especially important factor that plays critical roles in regulating circadian rhythm as well as many other physiological functions. Circadian misalignment not only disturbs the sleep/wake cycle and rhythmic physiological activity but also contributes to the development of various diseases, such as sleep disorders and neurodegenerative diseases. The patient with neurodegenerative diseases often experiences profound disruptions in their circadian rhythms and/or sleep/wake cycles. In addition, a growing body of recent evidence implicates sleep disorders as an early symptom of neurodegenerative diseases, and also suggests that abnormalities in the circadian system lead to the onset and expression of neurodegenerative diseases. The genetic mutations which cause the pathogenesis of familial neurodegenerative diseases have been well studied; however, with the exception of Huntington's disease, the majority of neurodegenerative diseases are sporadic. Interestingly, the dysfunction of microRNA is increasingly recognized as a cause of sporadic neurodegenerative diseases through the deregulated genes related to the pathogenesis of neurodegenerative disease, some of which are the causative genes of familial neurodegenerative diseases. Here we review the interplay of circadian rhythm disruption, sleep disorders and neurodegenerative disease, and its relation to microRNA, a key regulator of cellular processes.

Circulating MicroRNAs as Diagnostic Biomarkers for Motor Neuron Disease

Motor neuron disease (MND) is a kind of neurodegenerative disease that selectively invades spinal cord anterior horn cells, brainstem motor neurons, cortical pyramidal cells and the pyramidal tract. The main clinical features are the symptoms and signs of impaired upper and lower motor neurons, manifested as muscle weakness, atrophy and pyramidal tract signs. Histopathology has shown the disappearance of pyramidal cells in the motor cortex, loss of motor neurons in the anterior horn of the spinal cord and brainstem, and degeneration of the corticospinal tract. Due to the lack of effective treatment methods, the prognosis is generally poor, so it is of great significance to confirm the diagnosis early by various means. However, the current diagnosis of MND mainly relies on the combination of clinical manifestations and neurophysiological examinations, lacking effective means of early diagnosis. Circulating microRNA (CmiRNA) is a kind of stable miRNA molecule in serum, plasma and other body fluids, which has the characteristics of distinct differential expression, sensitive detection and convenient sample collection. As a possible new biomarker of MND, CmiRNA can not only reveal the pathophysiological process of MND, but also monitor disease progression and response to drug therapy. With the development of miRNA detection technology, more and more CmiRNAs as biomarkers with potential diagnostic value have been investigated. In this review, we explored the possibility of circulating samples as different sources of biomarkers for the diagnosis of MND, analyzing the progress of CmiRNA detection techniques, and presenting potential diagnostic MND biomarkers that have been reported.