Severity of hepatitis C virus (genotype-3) infection positively correlates with circulating microRNA-122 in patients sera

Biomarkers in Detection of Hepatitis C Virus Infection

The hepatitis C virus (HCV) infection affects 58 million people worldwide. In the United States, the incidence rate of acute hepatitis C has doubled since 2014; during 2021, this increased to 5% from 2020. Acute hepatitis C is defined by any symptom of acute viral hepatitis plus either jaundice or elevated serum alanine aminotransferase (ALT) activity with the detection of HCV RNA, the anti-HCV antibody, or hepatitis C virus antigen(s). However, most patients with acute infection are asymptomatic. In addition, ALT activity and HCV RNA levels can fluctuate, and a delayed detection of the anti-HCV antibody can occur among some immunocompromised persons with HCV infection. The detection of specific biomarkers can be of great value in the early detection of HCV infection at an asymptomatic stage. The high rate of HCV replication (which is approximately 1010 to 1012 virions per day) and the lack of proofreading by the viral RNA polymerase leads to enormous genetic diversity, creating a major challenge for the host immune response. This broad genetic diversity contributes to the likelihood of developing chronic infection, thus leading to the development of cirrhosis and liver cancer. Direct-acting antiviral (DAA) therapies for HCV infection are highly effective with a cure rate of up to 99%. At the same time, many patients with HCV infection are unaware of their infection status because of the mostly asymptomatic nature of hepatitis C, so they remain undiagnosed until the liver damage has advanced. Molecular mechanisms induced by HCV have been intensely investigated to find biomarkers for diagnosing the acute and chronic phases of the infection. However, there are no clinically verified biomarkers for patients with hepatitis C. In this review, we discuss the biomarkers that can differentiate acute from chronic hepatitis C, and we summarize the current state of the literature on the useful biomarkers that are detectable during acute and chronic HCV infection, liver fibrosis/cirrhosis, and hepatocellular carcinoma (HCC).

Identification of microRNA-mRNA Regulatory Networks with Therapeutic Values in Alzheimer's Disease by Bioinformatics Analysis

Background

Alzheimer's disease (AD) is the most prevalent neurological disorder worldwide, affecting approximately 24 million individuals. Despite more than a century of research on AD, its pathophysiology is still not fully understood.

Objective

Recently, genetic studies of AD have focused on analyzing the general expression profile by employing high-throughput genomic techniques such as microarrays. Current research has leveraged bioinformatics advancements in genetic science to build upon previous efforts.

Methods

Data from the GSE118553 dataset used in this investigation, and the analyses carried out using programs such as Limma and BioBase. Differentially expressed genes (DEGs) and differentially expressed microRNAs (DEmiRs) associated with AD identified in the studied areas of the brain. Target genes of the DEmiRs identified using the MultiMiR package. Gene ontology (GO) completed using the Enrichr website, and the protein-protein interaction (PPI) network for these genes drawn using STRING and Cytoscape software.

Results

The findings introduced DEGs including CTNNB1, PAK2, MAP2K1, PNPLA6, IGF1R, FOXL2, DKK3, LAMA4, PABPN1, and GDPD5, and DEmiRs linked to AD (miR-106A, miR-1826, miR-1253, miR-10B, miR-18B, miR-101-2, miR-761, miR-199A1, miR-379 and miR-668), (miR-720, miR-218-2, miR-25, miR-602, miR-1226, miR-548K, miR-H1, miR-410, miR-548F2, miR-181A2), (miR-1470, miR-651, miR-544, miR-1826, miR-195, miR-610, miR-599, miR-323, miR-587 and miR-340), and (miR-1282, miR-1914, miR-642, miR-1323, miR-373, miR-323, miR-1322, miR-612, miR-606 and miR-758) in cerebellum, frontal cortex, temporal cortex, and entorhinal cortex, respectively.

Conclusions

The majority of the genes and miRNAs identified by our findings may be employed as biomarkers for prediction, diagnosis, or therapy response monitoring.

Circulating MicroRNA-122 as a Potential Biomarker for Hepatitis C Virus Induced Hepatocellular Carcinoma

Background: The microRNA (miRNA) mediated translational repression can cause various diseases in humans. The liver-specific miRNA (microRNA-122 (miR-122)) is primarily involved in tissue tropism during hepatitis C virus (HCV) infection which ultimately leads to hepatocellular carcinoma (HCC). Objectives: This study focuses on evaluating host serum miR-122 as a prognostic marker in HCV-induced hepatocellular carcinoma. Methods: Evaluation of miR-122 expression was carried out by quantitative real time PCR. Results: Positive expression of miR-122 was observed in patients with chronic hepatitis C (CHC) followed by HCC patients compared to healthy controls. A difference in median levels of the miR-122 expression in CHC and HCC patients (P < 0.000) was found in contrast to cirrhosis patients (P = 0.511). The serum miR-122 expression was found threefold higher in liver cirrhosis patients than chronic hepatitis. Further, the area under the receiver operating characteristic curve (AUROC) analysis of miR-122 expression profile can efficiently distinguish CHC patients (AUROC = 0.978, P = 0.000, 95% confidence interval (CI) = 0.958 to 0.998) and HCC from healthy controls (AUROC = 0.971, P = 0.000, 95% CI = 0.944 to 0.997). Moreover, receiver operating characteristic (ROC) curve analysis significantly distinguished between CHC patients from cirrhosis patients (AUROC = 0.955, P = 0.000, 95% CI = 0.925 to 0.986) but not CHC from HCC patients (AUROC = 0.584, P = 0.104, 95% CI = 0.485 to 0.684). This study revealed a substantial correlation of miR-122 with HCV viral load (r = 0.56, P = 0.000), ALT (r = 0.67, P = 0.000) and AST (r = 0.65, P = 0.000) levels. Conclusions: Serum miR-122 can potentially serve as a promising prognostic tool for HCV induced HCC.

Synaptosome microRNAs regulate synapse functions in Alzheimer's disease

MicroRNAs (miRNAs) are found in nerve terminals, synaptic vesicles, and synaptosomes, but it is unclear whether synaptic and cytosolic miRNA populations differ in Alzheimer's disease (AD) or if synaptosomal miRNAs affect AD synapse activity. To address these questions, we generated synaptosomes and cytosolic fractions from postmortem brains of AD and unaffected control (UC) samples and analyzed them using a global Affymetrix miRNAs microarray platform. A group of miRNAs significantly differed (P < 0.0001) with high fold changes variance (+/- >200-fold) in their expressions in different comparisons: (1) UC synaptosome vs UC cytosol, (2) AD synaptosomes vs AD cytosol, (3) AD cytosol vs UC cytosol, and (4) AD synaptosomes vs UC synaptosomes. MiRNAs data analysis revealed that some potential miRNAs were consistently different across sample groups. These differentially expressed miRNAs were further validated using AD postmortem brains, brains of APP transgenic (Tg2576), Tau transgenic (P301L), and wild-type mice. The miR-501-3p, miR-502-3p, and miR-877-5p were identified as potential synaptosomal miRNAs upregulated with disease progression based on AD Braak stages. Gene Ontology Enrichment and Ingenuity Pathway Analysis of synaptosomal miRNAs showed the involvement of miRNAs in nervous system development, cell junction organization, synapse assembly formation, and function of GABAergic synapse. This is the first description of synaptic versus cytosolic miRNAs in AD and their significance in synapse function.

Deregulated mitochondrial microRNAs in Alzheimer's disease: Focus on synapse and mitochondria

Alzheimer's disease (AD) is the most common cause of dementia and is currently one of the biggest public health concerns in the world. Mitochondrial dysfunction in neurons is one of the major hallmarks of AD. Emerging evidence suggests that mitochondrial miRNAs potentially play important roles in the mitochondrial dysfunctions, focusing on synapse in AD progression. In this meta-analysis paper, a comprehensive literature review was conducted to identify and discuss the (1) role of mitochondrial miRNAs that regulate mitochondrial and synaptic functions; (2) the role of various factors such as mitochondrial dynamics, biogenesis, calcium signaling, biological sex, and aging on synapse and mitochondrial function; (3) how synapse damage and mitochondrial dysfunctions contribute to AD; (4) the structure and function of synapse and mitochondria in the disease process; (5) latest research developments in synapse and mitochondria in healthy and disease states; and (6) therapeutic strategies that improve synaptic and mitochondrial functions in AD. Specifically, we discussed how differences in the expression of mitochondrial miRNAs affect ATP production, oxidative stress, mitophagy, bioenergetics, mitochondrial dynamics, synaptic activity, synaptic plasticity, neurotransmission, and synaptotoxicity in neurons observed during AD. However, more research is needed to confirm the locations and roles of individual mitochondrial miRNAs in the development of AD.

Hepatitis C Virus-Induced Exosomal MicroRNAs and Toll-Like Receptor 7 Polymorphism Regulate B-Cell Activating Factor

There are large gaps in understanding the molecular machinery accounting for the association of hepatitis C virus (HCV) infection with autoimmunity. Mixed cryoglobulinemia (MC) is the most common HCV-associated extrahepatic manifestation, which is characterized by B-cell lymphoproliferation and autoantibody production. B-cell activating factor (BAFF) is a member of the tumor necrosis factor family and plays an important role in B-cell proliferation. We explored the roles of hepatocyte-derived exosomal microRNAs (exo-miRNAs) and BAFF in the extrahepatic diseases of HCV infection. The exo-miRNA profiles were explored using a next-generation sequencing approach, followed by quantitative reverse transcription-PCR validation. The Toll-like receptor 7 (TLR7) polymorphism were analyzed using quantitative PCR. The biological function of exo-miRNAs and TLR7 polymorphism in BAFF expression was evaluated by using immunoblotting and enzyme-linked immunosorbent assay. Significantly increased levels of BAFF, exosomes, and TLR7 were found in HCV patients, particularly in those with MC (P < 0.005). HCV-infected hepatocyte-derived miR-122/let-7b/miR-206 upregulated BAFF expression in human macrophages through exosome transmission and TLR7 activation. Analysis of a TLR7 single-nucleotide polymorphism (rs3853839) revealed that G-allele carriers had increased TLR7 transcripts, resulting in more BAFF expression induced by hepatocyte-derived exo-miR-122, compared to those in C-allele carriers (P < 0.005). We identified HCV-infected hepatocyte-derived GU-enriched miRNAs (e.g., miR-122/let-7b/miR-206) as a TLR7 ligand that could induce BAFF production in macrophages through exosome transmission. The polymorphism in TLR7 is associated with the BAFF levels induced by exo-miR-122. It may be a potential predisposing factor of MC syndrome development.

The role of synaptic microRNAs in Alzheimer's disease

Structurally and functionally active synapses are essential for neurotransmission and for maintaining normal synaptic and cognitive functions. Researchers have found that synaptic dysfunction is associated with the onset and progression of neurodegenerative diseases, such as Alzheimer's disease (AD), and synaptic dysfunction is even one of the main physiological hallmarks of AD. MiRNAs are present in small, subcellular compartments of the neuron such as neural dendrites, synaptic vesicles, and synaptosomes are known as synaptic miRNAs. Synaptic miRNAs involved in governing multiple synaptic functions that lead to healthy brain functioning and synaptic activity. However, the precise role of synaptic miRNAs has not been determined in AD progression. This review emphasizes the presence of miRNAs at the synapse, synaptic compartments and roles of miRNAs in multiple synaptic functions. We focused on synaptic miRNAs alteration in AD, and how the modulation of miRNAs effect the synaptic functions in AD. We also discussed the impact of synaptic miRNAs in AD progression concerning the synaptic ATP production, mitochondrial function, and synaptic activity.

A New Discovery of MicroRNA-455-3p in Alzheimer's Disease

MicroRNA-455-3p (miR-455-3p) is identify as a member of broadly conserved miRNA family expressed in most of the phylum and species. In humans, miR-455 is present on the human chromosome 9 at locus 9q32 and encoded by the human COL27A1 gene (collagen type XXVII alpha 1 chain). The role of miR-455 has been implicated in various human diseases such as cartilage development, adipogenesis, preeclampsia, and cancers, e.g., colon cancer, prostate cancer, hepatocellular carcinoma, renal cancer, oral squamous cancer, skin cancer, and non-small cell lung cancer. Recently, our laboratory discovered the biomarker and therapeutic relevance of miR-455-3p in Alzheimer's disease (AD). Our global microarray analysis of serum samples from AD patients, mild cognitive individuals (MCI), and healthy subjects unveiled the high level of miR-455-3p in AD patients relative to MCI and healthy controls. Further, validation analysis using different kinds of AD samples such as serum, postmortem brains, AD fibroblasts, AD B-lymphocytes, AD cell lines, AD mouse models, and AD cerebrospinal fluid confirmed the biomarker potential of miR-455-3p. The mechanistic link of miR-455-3p in AD was determined via modulation of amyloid-β protein precursor (AβPP) and amyloid-β (Aβ) levels. Luciferase reporter assay confirmed AβPP as validated target of miR-455-3p. Our study on mouse neuroblastoma cells revealed the protective role of miR-455-3p against Aβ-induced toxicities. We also noticed that miR-455-3p enhances cell survival and lifespan extension. High level of miR-455-3p reduces Aβ toxicity, enhances mitochondrial biogenesis and synaptic activity, and maintains healthy mitochondrial dynamics. Based on these evidences, we cautiously conclude that miR-455-3p is a promising peripheral biomarker and therapeutic candidate for AD.

MicroRNA-138 promotes neuroblastoma SH-SY5Y cell apoptosis by directly targeting DEK in Alzheimer's disease cell model

BACKGROUND

Alzheimer's disease (AD) is a progressive neuro-degenerative disease with a major manifestation of dementia. MicroRNAs were reported to regulate the transcript expression in patients with Alzheimer's disease (AD). In this study, we investigated the roles of miR-138, a brain-enriched miRNA, in the AD cell model.

METHODS

The targets of miRNA-138 was predicted by bioinformatic analysis. The expression levels of DEK at both mRNA and protein levels were determined by qRT-PCR and Western blot, respectively. Luciferase assays were carried out to examine cell viabilities. Hoechst 33258 staining was used to detect cell apoptosis.

RESULTS

Our results demonstrated that the expression levels of miR-138 were increased in AD model, and DEK was a target of miR-138. Overexpression of miR-138 in SH-SY5Y cells obviously down-regulated the expression of DEK in SH-SY5Y cells, resulting in the inactivation of AKT and increased expression levels of proapoptotic caspase-3. MiR-138 mediated-suppression of DEK increased the susceptibility of cell apoptosis.

CONCLUSIONS

MicroRNA-138 promotes cell apoptosis of SH-SY5Y by targeting DEK in SH-SY5Y AD cell model. The regulation of miR-138 may contribute to AD via down-regulation of the DEK/AKT pathway.

ATG7 promotes autophagy in sepsis‑induced acute kidney injury and is inhibited by miR‑526b

Sepsis is considered to be the most common contributing factor in the development of acute kidney injury (AKI). However, the mechanisms by which sepsis leads to AKI remain unclear. Autophagy is important for a number of fundamental biological activities and plays a key role in numerous different diseases. The present study demonstrated that autophagy is involved in sepsis-induced kidney injury and upregulates ATG7, LC3 and Beclin I. In addition, it was revealed that miR-526b is decreased in sepsis-induced kidney injury, and miR-526b was identified as a direct regulator of ATG7. Furthermore, the present study investigated the biological effects of ATG7 inhibited by miR-526b and demonstrated that miR-526b could promote cell viability by inhibiting autophagy, potentially through targeting ATG7. In conclusion, the present study highlights the role of autophagy in sepsis-induced AKI, and miR-526b in regulating autophagy through targeting ATG7, which suggested that miR-526b may be a molecular therapeutic target for sepsis-induced AKI.

MicroRNAs mediate the anti-tumor and protective effects of ginsenosides

MicroRNAs (miRs(, as short non-coding RNAs, regulate important biological processes and mainly are associated with regulation of gene expression. The miRs are beneficial targets for diagnosis of various disorders, particularly cancer, since their expression profile undergoes alterations in pathological conditions. The numerous drugs have been designed with the capability of targeting miRs for treating pathological conditions. On the other hand, the application of naturally occurring compounds has been increased due to their minimal side effects and valuable biological and therapeutic activities. Ginsenosides are able to act as anti-tumor agents via either increasing or decreasing the expression level of miRs. Ginsenosides affect the expression profile of miRNAs to induce their protective impacts. Angiogenesis as a key factor in the progression of cancer can be suppressed by ginsenosides which is mediated by miR regulation. The aim of this review is to shed some light on the protective and anti-tumor activities of ginsenosides mediated by miRNAs.

Diagnostic value of circulating miRNA-122 for hepatitis B virus and/or hepatitis C virus-associated chronic viral hepatitis

Background: The liver-specific microRNA-122 (miR-122) has been demonstrated as a powerful and promising biomarker of hepatic diseases. However, the researches on the accuracy of miR122 detection in chronic viral hepatitis have been inconsistent, leading us to conduct this meta-analysis to systematically summarize the diagnostic value of circulating miR-122 in patients with hepatitis B virus (HBV) and/or hepatitis C virus (HCV)-associated chronic viral hepatitis.Methods: A comprehensive literature search (updated to January 30, 2019) in PubMed, Cochrane library, EMBASE, CNKI, Wanfang, and CQVIP databases was performed to identify eligible studies. The sensitivity (SEN), specificity (SPE), positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were pooled to explore the diagnostic performance of circulating miR-122. Subgroup and threshold effect analysis were further carried out to explore the heterogeneity.Results: Overall, 15 studies were finally included in this meta-analysis according to the exclusion and inclusion criteria. The pooled estimates indicated a moderately high diagnostic accuracy for circulating miR-122, with a sensitivity of 0.92 [95% confidence interval (CI), 0.86-0.95], a specificity of 0.84 (95% CI, 0.78-0.89), a PLR of 5.7 (95% CI, 4.7-8.1), a NLR of 0.1 (95% CI, 0.06-0.18), a DOR of 57 (95% CI 25-129), and an AUC of 0.93 (95% CI, 0.91-0.95). The subgroup analysis demonstrated that diagnostic accuracy was better for HCV-associated chronic viral hepatitis patients and non-Chinese compared with other subgroups. In addition, we found that serum might be a more promising matrix for detecting the expression of miR-122 than plasma.Conclusions: Our results demonstrated that circulating miR-122 have a relatively high diagnostic value for chronic viral hepatitis detection, especially in the patients with HCV-associated chronic viral hepatitis. However, further large cohort studies are still required to confirm our findings.

Novel MicroRNA-455-3p and its protective effects against abnormal APP processing and amyloid beta toxicity in Alzheimer's disease

The purpose of our study is to understand the protective role of miR-455-3p against abnormal amyloid precursor protein (APP) processing, amyloid beta (Aβ) formation, defective mitochondrial biogenesis/dynamics and synaptic damage in AD progression. In-silico analysis of miR-455-3p has identified the APP gene as a putative target. Using mutant APP cells, miR-455-3p construct, biochemical and molecular assays, immunofluorescence and transmission electron microscopy (TEM) analyses, we studied the protective effects of miR-455-3p on - 1) APP regulation, amyloid beta (Aβ)(1-40) & (1-42) levels, mitochondrial biogenesis & dynamics; 3) synaptic activities and 4) cell viability & apoptosis. Our luciferase reporter assay confirmed the binding of miR-455-3p at the 3'UTR of APP gene. Immunoblot, sandwich ELISA and immunostaining analyses revealed that the reduced levels of the mutant APP, Aβ(1-40) & Aβ(1-42), and C99 by miR-455-3p. We also found the reduced levels of mRNA and proteins of mitochondrial biogenesis (PGC1α, NRF1, NRF2, and TFAM) and synaptic genes (synaptophysin and PSD95) in mutant APP cells; on the other hand, mutant APP cells that express miR-455-3p showed increased mRNA and protein levels of biogenesis and synaptic genes. Additionally, expression of mitochondrial fission proteins (DRP1 and FIS1) were decreased while the fusion proteins (OPA1, Mfn1 and Mfn2) were increased by miR-455-3p. Our TEM analysis showed a decrease in mitochondria number and an increase in the size of mitochondrial length in mutant APP cells transfected with miR-455-3p. Based on these observations, we cautiously conclude that miR-455-3p regulate APP processing and protective against mutant APP-induced mitochondrial and synaptic abnormalities in AD.

MicroRNA-455-3p as a Potential Biomarker for Alzheimer's Disease: An Update

A non-invasive and early-detectable peripheral biomarker is urgently needed for Alzheimer's disease (AD). The present study is a step forward to verify the biomarker properties of human microRNA-455-3p (Hsa-miR-455-3p) in AD patients. Our previous findings on mild cognitive impaired subjects, AD patients and AD cells and mouse models unveiled the miR-455-3p as a potential peripheral biomarker for AD. In the current study, we verified the differential expression of miR-455-3p in postmortem AD brains obtained from NIH NeuroBioBank, and fibroblasts and B-lymphocytes from both familial and sporadic AD patients from Coriell Cell Repository of National Institutes on Aging. Total RNA was extracted from the fibroblasts, B-lymphocytes and AD postmortem brains, and expression of miR-455-3p was measured by real-time reverse-transcriptase RT-PCR. Our real-time RT-PCR analysis showed a significant (P = 0.0002) upregulation of miR-455-3p expression in AD postmortem brains compared to healthy control samples. Expression of miR-455-3p was also upregulated in the fibroblasts from AD patients, however a significant difference in miR-455-3p level was observed in the cells from sporadic AD patients (P = 0.014) compared to healthy controls. Similarly, in B-lymphocytes, miR-455-3p level was also higher (P = 0.044) especially in sporadic AD cases compared to controls. Receiver operating characteristic (ROC) curve analysis indicated the significant area under ROC curve (AUROC) value of miR-455-3p in AD postmortem brain (AUROC = 0.792; P = 0.001) and AD fibroblasts cells (AUROC = 0.861; P = 0.03), whereas in B-lymphocytes AUROC value of miR-455-3p was not significant. Further, in-silico analysis for miRNA targets predictions showed the binding capacity of miR-455-3p with several AD associated key genes such as APP, NGF, USP25, PDRG1, SMAD4, UBQLN1, SMAD2, TP73, VAMP2, HSPBAP1, and NRXN1. Hence, these observations further revealed that miR-455-3p is a potential biomarker for AD and its possible therapeutic target for AD.

MicroRNA-455-3p as a potential peripheral biomarker for Alzheimer's disease

The purpose of our study was to identify microRNAs (miRNAs) as early detectable peripheral biomarkers in Alzheimer's disease (AD). To achieve our objective, we assessed miRNAs in serum samples from AD patients and Mild cognitive impairment (MCI) subjects relative to healthy controls. We used Affymetrix microarray analysis and validated differentially expressed miRNAs using qRT-PCR. We further validated miRNA data using AD postmortem brains, amyloid precursor protein transgenic mice and AD cell lines. We identified a gradual upregulation of four miRNAs: miR-455-3p, miR-4668-5p, miR-3613-3p and miR-4674. A fifth miRNA, mir-6722, was down-regulated in persons with AD and mild cognitive impairment compared with controls. Validation analysis by qRT-PCR showed significant upregulation of only miR-455-3p (P = 0.007) and miR-4668-5p (P = 0.016) in AD patients compared with healthy controls. Furthermore, qRT-PCR analysis of the AD postmortem brains with different Braak stages also showed upregulation of miR-455-3p (P = 0.016). However, receiver operating characteristic curves (ROC) curve analysis revealed a significant area under curve (AUC) value only for miR-455-3p in the serum (AUROC = 0.79; P = 0.015) and brains (AUROC = 0.86; P = 0.016) of AD patients. Expression analysis of amyloid precursor protein transgenic mice also revealed high level of mmu-miR-455-3p (P = 0.004) in the cerebral cortex (AD-affected) region of brain and low in the non-affected area, i.e. cerebellum. Furthermore, human and mouse neuroblastoma cells treated with the amyloid-β(1-42) peptide also showed a similarly higher expression of miR-455-3p. Functional analysis of differentially expressed miRNAs via the miR-path indicated that miR-455-3p was associated in the regulation of several biological pathways. Genes associated with these pathways were found to have a crucial role in AD pathogenesis. An increase in miR-455-3p expression found in AD patients and Aβ pathologies unveiled its biomarker characteristics and a precise role in AD pathogenesis.

Serum microRNA-30c levels are correlated with disease progression in Xinjiang Uygur patients with chronic hepatitis B

We aimed to investigate the potential role and mechanism of microRNA-30c (miR-30c) in the pathological development of chronic hepatitis B (CHB). The serum levels of miR-30c in hepatitis B virus (HBV) carrier Xinjiang Uygur patients with inactive, low-replicative, high-replicative and HBe antigen-positive CHB were investigated. HepG2 cells were co-transfected with pHBV1.3 and miR-30c mimic or inhibitor or scramble RNA. The effects of miR-30c dysregulation on HBV replication and gene expression, cell proliferation and cell cycle were then investigated. miR-30c was down-regulated in Xinjiang Uygur patients with CHB compared to healthy controls and its expression level discriminated HBV carrier patients with inactive, low-replicative, high-replicative and HBe antigen-positive risk for disease progression. Overexpression of miR-30c significantly inhibited HBV replication and the expressions of HBV pgRNA, capsid-associated virus DNA and Hbx in hepatoma cells. Moreover, overexpression of miR-30c significantly inhibited cell proliferation and delayed G1/S phase transition in hepatoma cells. Opposite effects were obtained after suppression of miR-30c. Our results indicate that miR-30c was down-regulated in Xinjiang Uygur patients with CHB, and miR-30c levels could serve as a marker for risk stratification of HBV infection. Down-regulation of miR-30c may result in the progression of CHB via promoting HBV replication and cell proliferation.

MicroRNAs as Peripheral Biomarkers in Aging and Age-Related Diseases

MicroRNAs (miRNAs) are found in the circulatory biofluids considering the important molecules for biomarker study in aging and age-related diseases. Blood or blood components (serum/plasma) are primary sources of circulatory miRNAs and can release these in cell-free form either bound with some protein components or encapsulated with microvesicle particles, called exosomes. miRNAs are quite stable in the peripheral circulation and can be detected by high-throughput techniques like qRT-PCR, microarray, and sequencing. Intracellular miRNAs could modulate mRNA activity through target-specific binding and play a crucial role in intercellular communications. At a pathological level, changes in cellular homeostasis lead to the modulation of molecular function of cells; as a result, miRNA expression is deregulated. Deregulated miRNAs came out from cells and frequently circulate in extracellular body fluids as part of various human diseases. Most common aging-associated diseases are cardiovascular disease, cancer, arthritis, dementia, cataract, osteoporosis, diabetes, hypertension, and neurodegenerative diseases such as Alzheimer's disease, Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Variation in the miRNA signature in a diseased peripheral circulatory system opens up a new avenue in the field of biomarker discovery. Here, we measure the biomarker potential of circulatory miRNAs in aging and various aging-related pathologies. However, further more confirmatory researches are needed to elaborate these findings at the translation level.

Are circulating microRNAs peripheral biomarkers for Alzheimer's disease?

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss, multiple cognitive abnormalities and intellectual impairments. Currently, there are no drugs or agents that can delay and/or prevent the progression of disease in elderly individuals, and there are no peripheral biomarkers that can detect AD early in its pathogenesis. Research has focused on identifying biomarkers for AD so that treatment can be begun as soon as possible in order to restrict or prevent intellectual impairments, memory loss, and other cognitive abnormalities that are associated with the disease. One such potential biomarker is microRNAs that are found in circulatory biofluids, such as blood and blood components, serum and plasma. Blood and blood components are primary sources where miRNAs are released in either cell-free form and then bind to protein components, or are in an encapsulated form with microvesicle particles. Exosomal miRNAs are known to be stable in biofluids and can be detected by high throughput techniques, like microarray and RNA sequencing. In AD brain, enriched miRNAs encapsulated with exosomes crosses the blood brain barrier and secreted in the CSF and blood circulations. This review summarizes recent studies that have identified miRNAs in the blood, serum, plasma, exosomes, cerebral spinal fluids, and extracellular fluids as potential biomarkers of AD. Recent research has revealed only six miRNAs - miR-9, miR-125b, miR-146a, miR-181c, let-7g-5p, and miR-191-5p - that were reported by multiple investigators. Some studies analyzed the diagnostic potential of these six miRNAs through receiver operating curve analysis which indicates the significant area-under-curve values in different biofluid samples. miR-191-5p was found to have the maximum area-under-curve value (0.95) only in plasma and serum samples while smaller area-under-curve values were found for miR-125, miR-181c, miR-191-5p, miR-146a, and miR-9. This article shortlisted the promising miRNA candidates and discussed their diagnostic properties and cellular functions in order to search for potential biomarker for AD.

Parallel expression profiling of hepatic and serum microRNA-122 associated with clinical features and treatment responses in chronic hepatitis C patients

MicroRNAs (miRNAs) are small, non-coding RNAs that regulate a variety of biological processes. Recently, human liver-specific miRNA miR-122 has been reported to facilitate hepatitis C virus (HCV) replication in liver cells. HCV is one of the leading causes of liver diseases worldwide. In Pakistan, the estimated prevalence is up to 10%. Here, we report hepatic and serum miR-122 expression profiling from paired liver and serum samples from treatment-naive chronic hepatitis C (CHC) patients and controls. We aimed to elucidate the biomarker potential of serum miR-122 for monitoring disease progression and predicting end treatment response (ETR). Hepatic miR-122 levels were significantly down-regulated in CHC patients. A significant inverse correlation was observed between hepatic and serum miR-122 levels, indicating that serum miR-122 levels reflect HCV-associated disease progression. Both hepatic and serum miR-122 were significantly correlated (P < 0.05) with several clinicopathological features of CHC. Receiver operator curve analysis showed that serum miR-122 had superior discriminatory ability even in patients with normal alanine transaminase levels. Multivariate logistic regression analysis highlighted pre-treatment serum miR-122 levels as independent predictors of ETR. In conclusion, serum miR-122 holds the potential to serve as a promising biomarker of disease progression and ETR in CHC patients.