Extracellular miRNAs: From Biomarkers to Mediators of Physiology and Disease

Extracellular vesicles carrying miR-6836 derived from resistant tumor cells transfer cisplatin resistance of epithelial ovarian cancer via DLG2-YAP1 signaling pathway

Background: Chemotherapy resistance is a significant cause for poor prognosis of epithelial ovarian cancer (EOC). However, the molecular mechanism of chemo-resistance remains unclear, and developing available therapies and effective biomarkers for resistant EOC is in urgent demand. Stemness of cancer cells directly results in chemo-resistance. Exosomal miRNAs rebuild tumor microenvironment (TME) and act as widely used clinical liquid biopsy markers. Methods: In our study, high throughput screenings and comprehensive analysis were performed to screen for miRNAs, which were both up-regulated in resistant EOC tissues and related to stemness, and miR-6836 was identified accordingly. Results: Clinically, high miR-6836 expression was closely correlated with poor chemotherapy response and survival for EOC patients. Functionally, miR-6836 promoted EOC cell cisplatin resistance by increasing stemness and suppressing apoptosis. Mechanistically, miR-6836 directly targeted DLG2 to enhance Yap1 nuclear translocation, and was regulated by TEAD1 forming the positive feedback loop: miR-6836-DLG2-Yap1-TEAD1. Furthermore, miR-6836 could be packaged into secreted exosomes in cisplatin-resistant EOC cells and exosomal miR-6836 was able to be delivered into cisplatin-sensitive EOC cells and reverse their cisplatin response. Conclusion: Our study revealed the molecular mechanisms of chemotherapy resistance, and identified miR-6836 as the possible therapeutic target and effective biopsy marker for resistant EOC.

Characteristics of plasma exosomes in drug-resistant tuberculosis patients

BACKGROUND

Increasing prevalence of drug-resistant tuberculosis (DR-TB) poses a major challenge to the early detection and effective control of tuberculosis (TB). Exosomes carrying proteins and nucleic acid mediate intercellular communication between host and pathogen including Mycobacterium tuberculosis. However, molecular events of exosomes indicating the status and development of DR-TB remain unknown. This study determined the proteomics of exosome in DR-TB and explored the potential pathogenesis of DR-TB.

METHODS

Plasma samples were collected from 17 DR-TB patients and 33 non-drug-resistant tuberculosis (NDR-TB) patients using grouped case-control study design. After exosomes of plasma were isolated and confirmed by compositional and morphological measurement for exosomal characteristics, a label-free quantitative proteomics of exosomes was performed and differential protein components were determined via bioinformatics analysis.

RESULTS

Compared with the NDR-TB group, we identified 16 up-regulated proteins and 10 down-regulated proteins in the DR-TB group. The down-regulated proteins were mainly apolipoproteins and mainly enriched in cholesterol metabolism-related pathways. Apolipoproteins family including APOA1, APOB, APOC1 were key proteins in protein-protein interaction network.

CONCLUSION

Differentially expressed proteins in the exosomes may indicate the status of DR-TB from NDR-TB. Apolipoproteins family including APOA1, APOB, APOC1 may be involved in the pathogenesis of DR-TB by regulating cholesterol metabolism via exosomes.

A Glance at Biogenesis and Functionality of MicroRNAs and Their Role in the Neuropathogenesis of Parkinson's Disease

MicroRNAs (miRNAs) are short, noncoding RNA transcripts. Mammalian miRNA coding sequences are located in introns and exons of genes encoding various proteins. As the central nervous system is the largest source of miRNA transcripts in living organisms, miRNA molecules are an integral part of the regulation of epigenetic activity in physiological and pathological processes. Their activity depends on many proteins that act as processors, transporters, and chaperones. Many variants of Parkinson's disease have been directly linked to specific gene mutations which in pathological conditions are cumulated resulting in the progression of neurogenerative changes. These mutations can often coexist with specific miRNA dysregulation. Dysregulation of different extracellular miRNAs has been confirmed in many studies on the PD patients. It seems reasonable to conduct further research on the role of miRNAs in the pathogenesis of Parkinson's disease and their potential use in future therapies and diagnosis of the disease. This review presents the current state of knowledge about the biogenesis and functionality of miRNAs in the human genome and their role in the neuropathogenesis of Parkinson's disease (PD)-one of the most common neurodegenerative disorders. The article also describes the process of miRNA formation which can occur in two ways-the canonical and noncanonical one. However, the main focus was on miRNA's use in in vitro and in vivo studies in the context of pathophysiology, diagnosis, and treatment of PD. Some issues, especially those regarding the usefulness of miRNAs in PD's diagnostics and especially its treatment, require further research. More standardization efforts and clinical trials on miRNAs are needed.

Role of microRNA carried by small extracellular vesicles in urological tumors

Small extracellular vesicles (sEVs) are minute vesicles secreted by various cells that are capable of transporting cargo, including microRNAs, between donor and recipient cells. MicroRNAs (miRNAs), small non-coding RNAs approximately 22 nucleotides in length, have been implicated in a wide array of biological processes, including those involved in tumorigenesis. Emerging evidence highlights the pivotal role of miRNAs encapsulated in sEVs in both the diagnosis and treatment of urological tumors, with potential implications in epithelial-mesenchymal transition, proliferation, metastasis, angiogenesis, tumor microenvironment and drug resistance. This review provides a brief overview of the biogenesis and functional mechanisms of sEVs and miRNAs, followed by a summarization of recent empirical findings on miRNAs encapsulated in sEVs from three archetypal urologic malignancies: prostate cancer, clear cell renal cell carcinoma, and bladder cancer. We conclude by underscoring the potential of sEV-enclosed miRNAs as both biomarkers and therapeutic targets, with a particular focus on their detection and analysis in biological fluids such as urine, plasma, and serum.

Microarray analysis of hub genes, non-coding RNAs and pathways in lung after whole body irradiation in a mouse model

PURPOSE

Previous research has highlighted the impact of radiation damage, with cancer patients developing acute disorders including radiation induced pneumonitis or chronic disorders including pulmonary fibrosis months after radiation therapy ends. We sought to discover biomarkers that predict these injuries and develop treatments that mitigate this damage and improve quality of life.

MATERIALS AND METHODS

Six- to eight-week-old female C57BL/6 mice received 1, 2, 4, 8, 12 Gy or sham whole body irradiation. Animals were euthanized 48 h post exposure and lungs removed, snap frozen and underwent RNA isolation. Microarray analysis was performed to determine dysregulation of messenger RNA (mRNA), microRNA (miRNA), and long non-coding RNA (lncRNA) after radiation injury.

RESULTS

We observed sustained dysregulation of specific RNA markers including: mRNAs, lncRNAs, and miRNAs across all doses. We also identified significantly upregulated genes that can indicate high dose exposure, including Cpt1c, Pdk4, Gdf15, and Eda2r, which are markers of senescence and fibrosis. Only three miRNAs were significantly dysregulated across all radiation doses: miRNA-142-3p and miRNA-142-5p were downregulated and miRNA-34a-5p was upregulated. IPA analysis predicted inhibition of several molecular pathways with increasing doses of radiation, including: T cell development, Quantity of leukocytes, Quantity of lymphocytes, and Cell viability.

CONCLUSIONS

These RNA biomarkers might be highly relevant in the development of treatments and in predicting normal tissue injury in patients undergoing radiation treatment. We are conducting further experiments in our laboratory, which includes a human lung-on-a-chip model, to develop a decision tree model using RNA biomarkers.

Sequencing and bioinformatics analysis of miRNA from rat endplate chondrogenic exosomes

Exosomes have a key role in various diseases, such as arthritis, heart disease and respiratory disease. Exosomes from various sources have also been indicated to improve intervertebral disc degeneration. However, the role of endplate chondrogenic exosomes in intervertebral disc degeneration has remained largely elusive. The aim of the present study was to compare exosomal microRNA (miRNA) expression patterns in endplate chondrocytes before and after degeneration, and their potential roles in the pathogenesis of intervertebral disc degeneration (IVDD). Endplate chondrocytes were extracted from rats and cultured to obtain pre- and post-degeneration chondrocytes. Exosomes were obtained from the chondrocytes by centrifugation. The two groups of exosomes were subjected to small RNA sequencing, miRNA identification, novel miRNA prediction, quantitative analysis of miRNA expression and differentially expressed (DE) miRNA screening, in addition to miRNA target gene (TG) prediction and TG functional annotation and enrichment analysis. The percentage of miRNAs isolated from the exosomes before and after degeneration was found to differ. A total of 58 DE miRNAs were analyzed, the expression levels of which were significantly different post-degeneration compared with pre-degeneration. Cell experiments were also performed, in which the exosomes were co-cultured with nucleus pulposus (NP) cells. The results indicated that the chondrocyte-derived exosomes were taken up by the NP cells and influenced the expression of aggrecan and collagen 1A and 2A, suggesting that they may inhibit IVDD via their action on NP cells. The specific miRNAs present in exosomes during IVDD may be used to develop new targets for the treatment and diagnosis of this condition. DE exosomal miRNAs derived from endplate cartilage pre- and post-degeneration may be associated with the risk of IVDD and could help to distinguish patients with IVDD. Furthermore, the expression of certain miRNAs may be associated with disease progression, which may contribute to understanding the pathophysiology of IVDD from an epigenetic perspective.

MiR-146a-5p delivered by hucMSC extracellular vesicles modulates the inflammatory response to sulfur mustard-induced acute lung injury

BACKGROUND

Sulfur mustard (SM) is a highly toxic chemical warfare agent that has caused numerous casualties during wars and conflicts in the past century. Specific antidotes or therapeutic strategies are rare due to the complicated mechanism of toxicity, which still awaits elucidation. Clinical data show that acute lung injury (ALI) is responsible for most mortality and morbidity after SM exposure. Extracellular vesicles are natural materials that participate in intercellular communication by delivering various substances and can be modified. In this study, we aim to show that extracellular vesicles derived from human umbilical cord mesenchymal stromal cells (hucMSC-EVs) could exert therapeutic effects on SM-induced ALI, and to explain the underlying mechanism of effects.

METHODS

MiR-146a-5p contained in hucMSC-EVs may be involved in the process of hucMSC-EVs modulating the inflammatory response to SM-induced ALI. We utilized miR-146a-5p delivered by extracellular vesicles and further modified hucMSCs with a miR-146a-5p mimic or inhibitor to collect miR-146a-5p-overexpressing extracellular vesicles (miR-146a-5p⁺-EVs) or miR-146a-5p-underexpressing extracellular vesicles (miR-146a-5p^--EVs), respectively. Through in vivo and in vitro experiments, we investigated the mechanism.

RESULTS

The effect of miR-146a-5p⁺-EVs on improving the inflammatory reaction tied to SM injury was better than that of hucMSC-EVs. We demonstrated that miR-146a-5p delivered by hucMSC-EVs targeted TRAF6 to negatively regulate inflammation in SM-induced ALI models in vitro and in vivo.

CONCLUSION

In summary, miR-146a-5p delivered by hucMSC-EVs targeted TRAF6, causing hucMSC-EVs to exert anti-inflammatory effects in SM-induced ALI; thus, hucMSC-EVs treatment may be a promising clinical therapeutic after SM exposure.

Exosomal miR-141-3p from PDLSCs Alleviates High Glucose-Induced Senescence of PDLSCs by Activating the KEAP1-NRF2 Signaling Pathway

Human periodontal ligament stem cells (PDLSCs) are the most promising stem cells for periodontal tissue engineering. Senescent PDLSCs have diminished abilities to proliferate and differentiate, affecting the efficiency of periodontal tissue repair and regeneration. Stem cell-derived exosomes are important participants in intercellular information exchange and can help ameliorate senescence. In this study, we investigated PDLSC senescence in a high glucose microenvironment as well as the ability of human periodontal ligament stem cell-derived exosomes (PDLSC-Exos) to alleviate cellular senescence and the underlying mechanisms. Herein, PDLSCs and PDLSC-Exos were isolated and extracted. Then, cellular senescence indicators were evaluated after high glucose (25 mM) treatment of cultured PDLSCs. PDLSC-Exos were cocultured with senescent PDLSCs to further explore the role of PDLSC-Exos in cellular senescence and determine the differences in cellular oxidative stress levels after PDLSC-Exo treatment. Next, we investigated whether PDLSC-Exos alleviated cellular senescence by restoring the balance of oxidative stress signals and explored the underlying molecular pathways. We discovered that PDLSCs underwent premature senescence due to high glucose culture, but they were rejuvenated by PDLSC-Exos. The rejuvenating effects of PDLSC-Exos were notably reversed by cotreatment with ML385, an inhibitor of nuclear factor erythroid 2-related factor 2 (NRF2), indicating that this recovery depended on NRF2 activation. Further analyses revealed that microRNA-141-3p (miR-141-3p) was expressed at relatively high levels in PDLSC-Exos and was instrumental in PDLSC-Exo-mediated restoration by downregulating Kelch-like ECH-associated protein 1 (KEAP1), which is a negative regulator of NRF2 expression. Our findings suggest that PDLSC-Exos alleviate high glucose-induced senescence of PDLSCs by transferring miR-141-3p to activate the KEAP1-NRF2 signaling pathway. Based on this research, PDLSC-Exos may behave similarly to their parental PDLSCs and have significant effects on cellular senescence by delivering their encapsulated bioactive chemicals to target cells.

Circulating and extracellular vesicle-derived microRNAs as biomarkers in bone-related diseases

MicroRNAs (miRNA) are small non-coding RNA molecules that regulate posttranscriptional gene expression by repressing messengerRNA-targets. MiRNAs are abundant in many cell types and are secreted into extracellular fluids, protected from degradation by packaging in extracellular vesicles. These circulating miRNAs are easily accessible, disease-specific and sensitive to small changes, which makes them ideal biomarkers for diagnostic, prognostic, predictive or monitoring purposes. Specific miRNA signatures can be reflective of disease status and development or indicators of poor treatment response. This is especially important in malignant diseases, as the ease of accessibility of circulating miRNAs circumvents the need for invasive tissue biopsy. In osteogenesis, miRNAs can act either osteo-enhancing or osteo-repressing by targeting key transcription factors and signaling pathways. This review highlights the role of circulating and extracellular vesicle-derived miRNAs as biomarkers in bone-related diseases, with a specific focus on osteoporosis and osteosarcoma. To this end, a comprehensive literature search has been performed. The first part of the review discusses the history and biology of miRNAs, followed by a description of different types of biomarkers and an update of the current knowledge of miRNAs as biomarkers in bone related diseases. Finally, limitations of miRNAs biomarker research and future perspectives will be presented.

Protocatechuic acid boosts continual efferocytosis in macrophages by derepressing KLF4 to transcriptionally activate MerTK

Macrophages clear apoptotic cells through a process called continual efferocytosis. We found that protocatechuic acid (PCA), a polyphenolic compound abundant in fruits and vegetables, increased the continual efferocytic capacity of macrophages and inhibited the progression of advanced atherosclerosis. PCA reduced the intracellular amounts of microRNA-10b (miR-10b) by promoting its secretion in extracellular vesicles, which led to an increase in the abundance of the miR-10b target Krüppel-like factor 4 (KLF4). In turn, KLF4 transcriptionally induced the gene encoding Mer proto-oncogene tyrosine kinase (MerTK), an efferocytic receptor for the recognition of apoptotic cells, resulting in increased continual efferocytic capacity. However, in naive macrophages, the PCA-induced secretion of miR-10b did not affect KLF4 and MerTK protein abundance or efferocytic capacity. In mice, oral administration of PCA increased continual efferocytosis in macrophages residing in the peritoneal cavities, thymi, and advanced atherosclerotic plaques through the miR-10b-KLF4-MerTK pathway. In addition, pharmacological inhibition of miR-10b with antagomiR-10b also increased the efferocytic capacity of efferocytic but not naive macrophages in vitro and in vivo. Together, these data describe a pathway that promotes continual efferocytosis in macrophages through miR-10b secretion and a KLF4-dependent increase in MerTK abundance, which can be activated by dietary PCA and which has implications for understanding the regulation of continual efferocytosis in macrophages.

Therapeutic potential of urine exosomes derived from rats with diabetic kidney disease

Kidney disease is prevalent in diabetes. Urinary exosomes (uE) from animal models and patients with Diabetic nephropathy (DN) showed increased levels of miRs with reno-protective potential. We examined whether urinary loss of such miRs is associated with their reduced renal levels in DN patients. We also tested whether injecting uE can leverage kidney disease in rats. In this study (study-1) we performed microarray profiling of miRNA in uE and renal tissues in DN patients and subjects with diabetes without DN (controls). In study-2, diabetes was induced in Wistar rats by Streptozotocin (i.p. 50 mg/kg of body weight). Urinary exosomes were collected at 6th, 7th and 8th weeks, and injected back into the rats (100ug/biweekly, uE-treated n=7) via tail vein on weeks 9 and 10. Equal volume of vehicle was injected in controls (vehicle, n=7). uE from the human and rat showed the presence of exosome-specific proteins by immunoblotting. Microarray profiling revealed a set of 15 miRs having high levels in the uE, while lower in renal biopsies, from DN, compared to controls (n=5-9/group). Bioinformatic analysis also confirmed the Renoprotective potential of these miRs. Taqman qPCR confirmed the opposite regulation of miR-200c-3p and miR-24-3p in paired uE and renal biopsy samples from DN patients (n=15), relative to non-DN controls. A rise in 28 miRs levels, including miR-200c-3p, miR-24-3p, miR-30a-3p and miR-23a-3p were observed in the uE of DN rats, collected between 6th-8th weeks, relative to baseline (before diabetes induction). uE- treated DN rats had significantly reduced urine albumin-to-creatinine ratio, attenuated renal pathology, and lower miR-24-3p target fibrotic/inflammatory genes (TGF-beta, and Collagen IV), relative to vehicle treated DN rats. In uE treated rats, the renal expression of miR-24-3p, miR-30a-3p, let-7a-5p and miR-23a-3p was increased, relative to vehicle control. Patients with diabetic nephropathy had reduced renal levels, while higher uE abundance of miRs with reno-protective potential. Reverting the urinary loss of miRs by injecting uE attenuated renal pathology in diabetic rats.

Advances of exosomal miRNAs in the diagnosis and treatment of ovarian cancer

Ovarian cancer is a tumor with the highest fatalities among female malignant tumors. This disease has no typical symptoms in its early stage, and most of the patients are in an advanced stage when being treated. The treatment effect is poor and it is easy to develop chemotherapy resistance. Therefore, it is particularly urgent to clarify the pathogenesis of ovarian cancer, explore its early diagnosis of biomarkers, and discover new treatment methods. As a carrier of intercellular information and genetic material transfer, exosomes are widely distributed in body fluids (e.g. blood and urine), which are regarded as latent tumor markers and take effects on tumor occurrence and invasion. Several articles have recently signified that exosomal miRNAs are widely implicated in the formation of the ovarian cancer tumor microenvironment, disease initiation and progression, and the generation of chemotherapy resistance. This article reviews the research on exosomal miRNAs in ovarian cancer.

Plasma-derived exosomal let-7c-5p, miR-335-3p, and miR-652-3p as potential diagnostic biomarkers for stable coronary artery disease

Objectives: Circulating exosomal microRNAs (miRNAs) have been identified as promising biomarkers for diagnosis of cardiovascular diseases. Nevertheless, the diagnostic potential of miRNAs in circulating exosomes for stable coronary artery disease (SCAD) remains unclear. We aim here to analyze the exosomal differentially expressed miRNAs (DEmiRNAs) in plasma of SCAD patients and investigate their diagnostic potential as SCAD biomarkers. Methods: Plasma was collected from SCAD patients and healthy controls, and exosomes were isolated by ultracentrifugation. Exosomal DEmiRNAs were analyzed by small RNA sequencing and were further validated by quantitative real-time PCR (qRT-PCR) in a larger set of plasma samples. Relationships between plasma exosomal let-7c-5p, miR-335-3p, miR-652-3p, genders and Gensini Scores in patients with SCAD were analyzed using correlation analyses. Moreover, we conducted receiver operating characteristic (ROC) curves for these DEmiRNAs and analyzed their possible functions and signaling pathways. Results: Vesicles isolated from plasma displayed all characteristics of exosomes. In the small RNA sequencing study, a total of 12 DEmiRNAs were identified, among which seven were verified to be statistically significant by qRT-PCR. The areas under the ROC curves of exosomal let-7c-5p, miR-335-3p, and miR-652-3p were 0.8472, 0.8029, and 0.8009, respectively. Exosomal miR-335-3p levels were positively correlated with Gensini scores of patients with SCAD. Bioinformatics analysis revealed that these DEmiRNAs may be involved in the pathogenesis of SCAD. Conclusion: Our findings indicated that plasma exosomal let-7c-5p, miR-335-3p, and miR-652-3p can be used as promising biomarkers for diagnosis of SCAD. In addition, plasma exosomal miR-335-3p levels coordinated with severity of SCAD.

Circulating MicroRNAs as Potential Biomarkers for Ischemic Stroke in Patients with Asymptomatic Intracranial Artery Stenosis

Circulating microRNAs have been shown to be biomarkers of various diseases. We aimed to investigate whether circulating microRNA can serve as a biomarker to predict ischemic stroke risk in asymptomatic intracranial artery stenosis. A total of 716 participants from the Asymptomatic Polyvascular Abnormalities Community study who had asymptomatic intracranial artery stenosis at baseline were enrolled (2010-11). Patients who suffered incident ischemic stroke were classified into the case group, and age- and sex-matched individuals without stroke were used as controls. MicroRNA microarrays were used to distinguish baseline circulating serum microRNA levels between the case and the control groups (GEO accession number GSE201860). The differentially expressed microRNAs were validated by real-time PCR. MicroRNA microarrays were performed in baseline serum samples from12 subjects who developed ischemic stroke and 12 age- and sex-matched subjects without stroke during the 2014-15 follow-up period. Twenty microRNAs were differentially expressed between the two groups (fold change > 1.3 and p < 0.05 for all). Hsa-miR-486-5p, hsa-miR-92a-3p, hsa-miR-6089 from them were selected and validated in the baseline serum samples of ten subjects with incident ischemic stroke and another ten age- and sex-matched subjects without stroke during the 2016-17 follow-up period. Hsa-miR-1225-5p, with a large fold change value and a reported relationship with cardiovascular or cerebrovascular diseases, was also validated. Ultimately, only hsa-miR-6089 was differentially downregulated among patients with intracranial artery stenosis who developed ischemic stroke (p < 0.05). In patients with asymptomatic intracranial artery stenosis, downregulated serum hsa-miR-6089 may be associated with the risk of ischemic stroke.

M2 Macrophage-Derived sEV Regulate Pro-Inflammatory CCR2+ Macrophage Subpopulations to Favor Post-AMI Cardiac Repair

Tissue-resident cardiac macrophage subsets mediate cardiac tissue inflammation and repair after acute myocardial infarction (AMI). CC chemokine receptor 2 (CCR2)-expressing macrophages have phenotypical similarities to M1-polarized macrophages, are pro-inflammatory, and recruit CCR2+ circulating monocytes to infarcted myocardium. Small extracellular vesicles (sEV) from CCR2̶ macrophages, which phenotypically resemble M2-polarized macrophages, promote anti-inflammatory activity and cardiac repair. Here, the authors harvested M2 macrophage-derived sEV (M2EV ) from M2-polarized bone-marrow-derived macrophages for intramyocardial injection and recapitulation of sEV-mediated anti-inflammatory activity in ischemic-reperfusion (I/R) injured hearts. Rats and pigs received sham surgery; I/R without treatment; or I/R with autologous M2EV treatment. M2EV rescued cardiac function and attenuated injury markers, infarct size, and scar size. M2EV inhibited CCR2+ macrophage numbers, reduced monocyte-derived CCR2+ macrophage recruitment to infarct sites, induced M1-to-M2 macrophage switching and promoted neovascularization. Analysis of M2EV microRNA content revealed abundant miR-181b-5p, which regulated macrophage glucose uptake, glycolysis, and mitigated mitochondrial reactive oxygen species generation. Functional blockade of miR-181b-5p is detrimental to beneficial M2EV actions and resulted in failure to inhibit CCR2+ macrophage numbers and infarct size. Taken together, this investigation showed that M2EV rescued myocardial function, improved myocardial repair, and regulated CCR2+ macrophages via miR-181b-5p-dependent mechanisms, indicating an option for cell-free therapy for AMI.

Omental cancer-associated fibroblast-derived exosomes with low microRNA-29c-3p promote ovarian cancer peritoneal metastasis

Ovarian cancer (OC) is characterized by frequent widespread peritoneal metastasis. Cancer-associated fibroblasts (CAFs) represent a critical stromal component of metastatic niche and promote omentum metastasis in OC patients. However, the role of exosomes derived from omental CAFs in metastasis remains unclear. We isolated exosomes from primary omental normal fibroblasts (NFs) and CAFs from OC patients (NF-Exo and CAF-Exo, respectively) and assessed their effect on metastasis. In mice bearing orthotopic OC xenografts, CAF-Exo treatment led to more rapid intraperitoneal tumor dissemination and shorter animal survival. Similar results were observed in mice undergoing intraperitoneal injection of tumor cells. Among the miRNAs downregulated in CAF-Exo, miR-29c-3p in OC tissues was associated with metastasis and survival in patients. Moreover, increasing miR-29c-3p in CAF-Exo significantly weakened the metastasis-promoting effect of CAF-Exo. Based on RNA sequencing, expression assays, and luciferase assays, matrix metalloproteinase 2 (MMP2) was identified as a direct target of miR-29c-3p. These results verify the significant contribution of exosomes from omental CAFs to OC peritoneal metastasis, which could be partially due to the relief of MMP2 expression inhibition mediated by low exosomal miR-29c-3p.

A Potential Immune-Related miRNAs Regulatory Network and Corresponding Diagnostic Efficacy in Schizophrenia

PURPOSE

Immune-related pathways actively participate in the progression of schizophrenia (SCZ), however, roles of immune-related miRNAs in SCZ are still unclear.

METHODS

A microarray expression study was conducted to explored roles of immune-related genes in SCZ. Functional enrichment analysis by using "clusterProfiler" was used to identify molecular alterations of SCZ. Protein-protein interaction (PPI) network was constructed and helped core molecular factors identification. Based on The Cancer Genome Atlas (TCGA) database, clinical significances of hub immune-related genes in cancers were also been explored. Then, correlation analyses were used to determine immune-related miRNAs. We further validated that hsa-miR-1299 could be an effective diagnostic biomarker for SCZ via analyzing multi-cohorts' data and quantitative real-time PCR (qRT-PCR).

RESULTS

A total of 455 mRNAs and 70 miRNAs that were differentially expressed between SCZ and control samples. Functional enrichment analysis based on differentially expressed genes (DEGs) hinted that immune-related pathways were significantly correlated with SCZ. Furthermore, a total of 35 immune-related genes that involved in disease onset and showed significant co-expressed relationships. Hub immune-related gene CCL4 and CCL22 are valuable in tumor diagnosis and survival prediction. Furthermore, we also identified 22 immune-related miRNAs that play important roles in this disease. An immune-related miRNAs-mRNAs regulatory network was constructed to provide miRNAs regulatory roles in SCZ. Core miRNAs expression status of hsa-miR-1299 were also validated in another cohort, which suggested its diagnostic performance for SCZ.

CONCLUSIONS

Our study reports the downregulation of some miRNAs in the process of SCZ are important. Shared genomics characteristics between SCZ and cancers also provide novel insights for cancers. A significant alteration of hsa-miR-1299 expression is effective as biomarker for the diagnosis of SCZ, suggesting that this miRNA could be a specific biomarker.

Extracellular Vesicles as Potential Therapeutic Messengers in Cancer Management

A deeper understanding of the communication mechanisms of tumor cells in a tumor microenvironment can improve the development of new therapeutic solutions, leading to a more personalized approach. Recently, the field of extracellular vesicles (EVs) has drawn attention due to their key role in intercellular communication. EVs are nano-sized lipid bilayer vesicles that are secreted by all types of cells and can function as intermediators of intercellular communication with the ability to transfer different cargo (proteins, nucleic acids, sugar…) types among cells. This role of EVs is essential in a cancer context as it can affect tumor promotion and progression and contribute to the pre-metastatic niche establishment. Therefore, scientists from basic, translational, and clinical research areas are currently researching EVs with great expectations due to their potential to be used as clinical biomarkers, which are useful for disease diagnosis, prognosis, patient follow-up, or even as vehicles for drug delivery due to their natural carrier nature. The application of EVs presents numerous advantages as drug delivery vehicles, namely their capacity to overcome natural barriers, their inherent cell-targeting properties, and their stability in the circulation. In this review, we highlight the distinctive features of EVs, their application as efficient drug delivery systems, and their clinical applications.

Basic Pathogenic Mechanisms and Epigenetic Players Promoted by Extracellular Vesicles in Vascular Damage

Both progression from the early pathogenic events to clinically manifest cardiovascular diseases (CVD) and cancer impact the integrity of the vascular system. Pathological vascular modifications are affected by interplay between endothelial cells and their microenvironment. Soluble factors, extracellular matrix molecules and extracellular vesicles (EVs) are emerging determinants of this network that trigger specific signals in target cells. EVs have gained attention as package of molecules with epigenetic reversible activity causing functional vascular changes, but their mechanisms are not well understood. Valuable insights have been provided by recent clinical studies, including the investigation of EVs as potential biomarkers of these diseases. In this paper, we review the role and the mechanism of exosomal epigenetic molecules during the vascular remodeling in coronary heart disease as well as in cancer-associated neoangiogenesis.

Vascular endothelial cell-derived exosomal miR-1246 facilitates posterior capsule opacification development by targeting GSK-3β in diabetes mellitus

Posterior capsule opacification (PCO) is a serious complication after cataract surgery. Diabetes could increase the occurrence of PCO, but the mechanism is still unclear. The purpose of this study is to investigate the role of small extracellular vesicles (sEVs) derived from diabetic aqueous humor in PCO process. Intraoperatively-derived aqueous humor sEVs from patients with diabetic related cataract (DRC) promoted the epithelial-mesenchymal transition (EMT) and metastasis of human lens epithelial cells (LECs). Via mouse PCO surgical model and DiI labeled fluorescence detection of sEVs, the sEVs derived from vascular endothelium were discovered directly contacting with LECs. Furthermore, we demonstrated that high-glucose-cultured human umbilical vein endothelial cells (HUVEC) -derived sEVs facilitated EMT process of HLE-B3 using co-culture model in vitro. MiRNA-seq data and GEO datasets analysis revealed that miR-1246 was essential in EMT process with diabetes. The miR-1246 was highly expressed in diabetic aqueous humor sEVs and high-glucose-treated vascular-endothelial-cell-derived sEVs. Moreover, miR-1246 promoted the metastasis and EMT process of HLE-B3 cells by directly targeting GSK-3β. Inhibiting miR-1246 could negatively regulated EMT. This finding might serve as a potential therapy for diabetic PCO.

Effects of Plasma-Derived Exosomal miRNA-19b-3p on Treg/T Helper 17 Cell Imbalance in Behçet's Uveitis

Purpose

To explore the potential role of plasma-derived exosomal microRNAs (miRNAs) in the development of regulatory T cell (Treg)/T helper 17 (Th17) cell imbalances in Behçet's uveitis (BU).

Methods

The exosome treatment was conducted to evaluate the effects of plasma exosomes from patients with active BU and healthy controls on the Treg/Th17 cell balance. miRNA sequencing analysis of plasma exosomes was conducted to identify differentially expressed miRNAs between patients with active BU and healthy controls. miRTarBase analysis and dual-luciferase reporter assays were conducted to identify the target genes of miR-19b-3p. CD4+T cells were transfected with miR-19b-3p mimic or inhibitor to evaluate its regulation of the Treg/Th17 cell balance. The Treg/Th17 cell balance in CD4+T cells was evaluated by flow cytometry and enzyme-linked immunosorbent assay.

Results

Exosomes from patients with active BU promoted Th17 cell differentiation and inhibited Treg cell differentiation. MiRNA sequencing analysis revealed 177 upregulated and 274 downregulated miRNAs in plasma exosomes of patients with active BU. Among them, miR-19b-3p was significantly elevated, and its target genes were identified as being involved in T-cell differentiation. miR-19b-3p overexpression downregulated CD46 expression and the Treg/Th17 cell ratio in CD4+T cells from healthy controls, whereas miR-19b-3p inhibition reversed these regulatory effects and restored the Treg/Th17 cell balance of CD4+T cells from patients with active BU.

Conclusions

Plasma-derived exosomes from patients with active BU showed a markedly differential miRNA expression in comparison to healthy controls. Highly expressed miRNA-19b-3p could induce a Treg/Th17 cell imbalance, probably by downregulating CD46 expression.

Apoptotic Vesicles Regulate Bone Metabolism via the miR1324/SNX14/SMAD1/5 Signaling Axis

Mesenchymal stem cells (MSCs) are widely used in the treatment of diseases. After their in vivo application, MSCs undergo apoptosis and release apoptotic vesicles (apoVs). This study investigates the role of apoVs derived from human bone marrow mesenchymal stem cells (hBMMSCs) in bone metabolism and the molecular mechanism of the observed effects. The results show that apoVs can promote osteogenesis and inhibit osteoclast formation in vitro and in vivo. ApoVs may therefore attenuate the bone loss caused by primary and secondary osteoporosis and stimulate bone regeneration in areas of bone defect. The mechanisms responsible for apoV-induced bone regeneration include the release of miR1324, which inhibit expression of the target gene Sorting Nexin 14 (SNX14) and thus activate the SMAD1/5 pathway in target cells. Given that MSC-derived apoVs are easily obtained and stored, with low risks of immunological rejection and neoplastic transformation, The findings suggest a novel therapeutic strategy to treat bone loss, including via cell-free approaches to bone tissue engineering.

The preliminary study of exosomes derived from thymosin beta 4-treated adipose-derived stem cells in fat grafting

BACKGROUND

The retention rate in autologous fat grafting is an increasing concern for surgeons and patients. Our previous research verified that thymosin beta 4 (Tβ4) positively affected fat survival, while the mechanism was unknown. The endothelial cells (ECs) and exosomes derived from adipose-derived stem cells (ADSCs) were regarded to play a critical role in fat transplantation.

OBJECTIVE

This study aimed to evaluate the effect of exosomes derived from Tβ4-treated ADSCs on EC proliferation and to identify the exosomal microRNA (miRNA) profile compared with the Tβ4-untreated group. Additionally, this research intended to recognize the related molecules and signaling pathways in the Tβ4-treated group with potential roles in fat transplants.

METHODS

ADSCs were collected from patients who underwent liposuction surgery. Depending on whether the medium was supplemented with exogenous Tβ4 or not, exosomes derived from cultured ADSCs were divided into the Tβ4-Exos group and Con-Exos group. Exosome uptake and cell counting kit-8 (CCK-8) assays assessed the influence of Tβ4-Exos on EC proliferation. The exosomal miRNAs of the two groups were analyzed by next-generation sequencing. With the criteria at the |log₂ (fold change)| ≥ 1 and p-value < 0.05, up-regulated and down-regulated differentially expressed miRNAs (DEMs) were obtained. Prediction databases were used to predict the downstream mRNAs for DEMs. And then, overlapping genes for the up-regulated DEMs and the down-regulated were screened out, followed by enrichment analysis, protein-protein interaction network construction, and the gene cluster and hub gene identification.

RESULTS

ADSCs were obtained from four female patients. The exosome uptake and CCK-8 assays showed that the Tβ4-Exos could increase cell growth rate compared with the control group (DMEM-H + PBS). In Tβ4-Exos and Con-Exos groups, 2651 exosomal miRNAs were recognized, with 80 up-regulated and 99 down-regulated DEMs according to the criteria. After the prediction, 621 overlapping genes for the up-regulated and 572 for the down-regulated DEMs were screened. The subsequent bioinformatics analysis found specific molecules and pathways related to the positive effect on fat survival.

CONCLUSIONS

The exosomes derived from Tβ4-treated ADSCs probably positively affect EC proliferation. Compared with the Con-Exos group, several exosomal DEMs, genes, and pathways were distinguished. These findings of this exploratory study provide the potential direction for future in-depth research on fat grafting.

miR-26a deficiency is associated with bone loss and reduced muscle strength but does not affect severity of cartilage damage in osteoarthritis

Osteoarthritis (OA) is the most common age-related joint disease. However, the role of many microRNAs (miRNA) in skeletal development and OA pathogenesis has not been sufficiently elucidated using genetically modified mice with gain- and loss-of-function models. We generated Cartilage-specific miR-26a overexpressing (Col2a1-Cre;miR-26a Tg^fl/fl: Cart-miR-26a Tg) mice and global miR-26a knockout (miR-26a KO) mice. The purpose of the present study was to determine the role of miR-26a in OA pathogenesis using aging and surgically induced models. Skeletal development of Cart-miR-26a Tg and miR-26a KO mice was grossly normal. Knee joints were evaluated by histological grading systems. In surgically-induced OA and aging models (12 and 18 months of age), Cart-miR-26a Tg mice and miR-26a KO mice exhibited OA-like changes such as proteoglycan loss and cartilage fibrillation with no significant differences in OARSI score (damage of articular cartilage) compared with control mice. However, miR-26a KO mice reduced muscle strength and bone mineral density at 12 months of age. These findings indicated that miR-26a modulates bone loss and muscle strength but has no essential role in aging-related or post-traumatic OA.

Exosomes secreted from cardiomyocytes suppress the sensitivity of tumor ferroptosis in ischemic heart failure

Heart failure (HF) patients in general have a higher risk of developing cancer. Several animal studies have indicated that cardiac remodeling and HF remarkably accelerate tumor progression, highlighting a cause-and-effect relationship between these two disease entities. Targeting ferroptosis, a prevailing form of non-apoptotic cell death, has been considered a promising therapeutic strategy for human cancers. Exosomes critically contribute to proximal and distant organ-organ communications and play crucial roles in regulating diseases in a paracrine manner. However, whether exosomes control the sensitivity of cancer to ferroptosis via regulating the cardiomyocyte-tumor cell crosstalk in ischemic HF has not yet been explored. Here, we demonstrate that myocardial infarction (MI) decreased the sensitivity of cancer cells to the canonical ferroptosis activator erastin or imidazole ketone erastin in a mouse model of xenograft tumor. Post-MI plasma exosomes potently blunted the sensitivity of tumor cells to ferroptosis inducers both in vitro in mouse Lewis lung carcinoma cell line LLC and osteosarcoma cell line K7M2 and in vivo with xenograft tumorigenesis model. The expression of miR-22-3p in cardiomyocytes and plasma-exosomes was significantly upregulated in the failing hearts of mice with chronic MI and of HF patients as well. Incubation of tumor cells with the exosomes isolated from post-MI mouse plasma or overexpression of miR-22-3p alone abrogated erastin-induced ferroptotic cell death in vitro. Cardiomyocyte-enriched miR-22-3p was packaged in exosomes and transferred into tumor cells. Inhibition of cardiomyocyte-specific miR-22-3p by AAV9 sponge increased the sensitivity of cancer cells to ferroptosis. ACSL4, a pro-ferroptotic gene, was experimentally established as a target of miR-22-3p in tumor cells. Taken together, our findings uncovered for the first time that MI suppresses erastin-induced ferroptosis through releasing miR-22-3p-enriched exosomes derived from cardiomyocytes. Therefore, targeting exosome-mediated cardiomyocyte/tumor pathological communication may offer a novel approach for the ferroptosis-based antitumor therapy.

The Role of MicroRNA in the Pathogenesis of Diabetic Nephropathy

Diabetic nephropathy is one of the most common and severe complications of diabetes mellitus, affecting one in every five patients suffering from diabetes. Despite extensive research, the exact pathogenesis of diabetic nephropathy is still unclear. Several factors and pathways are known to be involved in the development of the disease, such as reactive oxygen species or the activation of the renin–angiotensin–aldosterone system. The expression of those proteins might be extensively regulated by microRNA. Recent research suggests that in diabetic nephropathy patients, the profile of miRNA is significantly changed. In this review, we focus on the actions of miRNA in various pathways involved in the pathogenesis of diabetic nephropathy and the clinical usage of miRNAs as biomarkers and therapeutic targets.

Peripheral Biomarkers in Manifest and Premanifest Huntington's Disease

Huntington's disease (HD) is characterized by clinical motor impairment (e.g., involuntary movements, poor coordination, parkinsonism), cognitive deficits, and psychiatric symptoms. An inhered expansion of the CAG triplet in the huntingtin gene causing a pathogenic gain-of-function of the mutant huntingtin (mHTT) protein has been identified. In this review, we focus on known biomarkers (e.g., mHTT, neurofilament light chains) and on new biofluid biomarkers that can be quantified in plasma or peripheral blood mononuclear cells from mHTT carriers. Circulating biomarkers may fill current unmet needs in HD management: better stratification of patients amenable to etiologic treatment; the initiation of preventive treatment in premanifest HD; and the identification of peripheral pathogenic central nervous system cascades.

Target-catalyzed self-assembled spherical G-quadruplex/hemin DNAzymes for highly sensitive colorimetric detection of microRNA in serum

The accurate and visual detection of circulating microRNA (miRNA) has attracted increasing interest due to its pivotal role in clinical disease diagnosis. Taking advantages of nucleic acid isothermal amplification and enzyme-catalyzed chromogenic reaction, here, a colorimetric sensing strategy was proposed for sensitive miRNA analysis. When the target miRNA was present, local catalytic hairpin assembly (CHA) would be triggered and proceed continuously to form dozens of double-stranded oligonucleotides with G-rich sticky ends on the gold nanoparticle, which could self-assemble into a spherical G-quadruplex (GQ)/hemin DNAzyme by binding with hemin and potassium ions. As a horseradish peroxidase-mimic, GQ/hemin DNAzyme could catalyze the redox reaction and color change of the substrates. Taking miRNA-21 as an example, the developed method exhibited satisfactory specificity as well as high sensitivity with a detection limit of 90.3 fM. Furthermore, the sensing platform has been successfully employed to detect miRNA-21 in spiked serum, providing a promising tool for early diagnosis of cancers.

Extracellular vesicles from PBDE-47 treated M(LPS) THP-1 macrophages modulate the expression of markers of epithelial integrity, EMT, inflammation and muco-secretion in ALI culture of airway epithelium

AIMS

The lung epithelial cells form a physical barrier to the external environment acting as the first line of defence against potentially harmful environmental stimuli. These cells interact with several other cellular components, of which macrophages are some of the most relevant. We analysed the effects of the PBDE-47 on the microRNA cargo of THP-1 macrophage like derived small Extracellular Vesicles (sEVs) and the effects on A549 lung epithelial cells.

MAIN METHODS

sEVs from M(LPS) THP-1 macrophage-like cells after PBDE-47 treatment (sEVs^PBDE+LPS) were characterized by nanoparticle tracking analysis and their microRNA cargo studied by qPCR. Confocal microscopy was applied to study sEVs cellular uptake by A549 cells. The expression of tight junctions (TJs), adhesion molecules, inflammation markers and mucus production in A549 cultured in air liquid interface (ALI) conditions were studied by Real Time PCR and confocal microscopy.

KEY FINDINGS

sEVs^PBDE+LPS microRNA cargo analysis showed that the PBDE-47 modulated the expression of the miR-15a-5p, miR29a-3p, miR-143-3p and miR-122-5p. Furthermore, ALI cultured A549 cells incubated with sEVs^PBDE+LPS showed that zonula occludens-1 (p ≤ 0.04), claudin (p ≤ 0.02), E-cadherin (p ≤ 0.006) and Vimentin (p ≤ 0.0008) mRNAs were increased in A549 cells after sEVs^PBDE+LPS treatment. Indeed, Interleukin (IL)-8 (p ≤ 0.008) and mucin (MUC5AC and MUC5B) (p ≤ 0.03 and p ≤ 0.0001) mRNA expression were up- and down-regulated, respectively.

SIGNIFICANCE

PBDE-47 treated macrophages secrete sEVs with altered microRNA cargo that affect the mRNA expression of TJs, adhesion molecules, cytokines and EMT markers damaging the normal function of the lung epithelium, potentially contributing to the development of lung diseases.

Exosome-mediated inhibition of microRNA-449a promotes the amplification of mouse retinal progenitor cells and enhances their transplantation in retinal degeneration mouse models

Inherited and age-related retinal degenerations are the commonest causes of blindness without effective treatments. Retinal progenitor cells (RPCs), which have the multipotency to differentiate into various retinal cell types, are regarded as a promising source of cell transplantation therapy for retinal degenerative diseases. However, the self-limited expansion of RPCs causes difficulty in cell source supply and restrict its clinical treatment. In this work, we found that inhibition of microRNA-449a (miR-449a) in RPCs can promote proliferation and inhibit apoptosis of RPCs, partially through upregulating Notch signaling. Further optimization of transduction miR-449a inhibitor into RPCs by endothelial cell-derived exosomes can promote the survival of RPCs transplanted in vivo and reduce cell apoptosis in retinal degeneration mouse models. In summary, these studies have shown that exosome-miR-449a inhibitor can effectively promote the expansion of RPCs in vitro and enhance transplanted RPCs survival in vivo, which might provide a novel intervention strategy for retinal degenerations in the future.

Droplet Digital PCR Quantification of Selected Intracellular and Extracellular microRNAs Reveals Changes in Their Expression Pattern during Porcine In Vitro Adipogenesis

Extracellular miRNAs have attracted considerable interest because of their role in intercellular communication, as well as because of their potential use as diagnostic and prognostic biomarkers for many diseases. It has been shown that miRNAs secreted by adipose tissue can contribute to the pathophysiology of obesity. Detailed knowledge of the expression of intracellular and extracellular microRNAs in adipocytes is thus urgently required. The system of in vitro differentiation of mesenchymal stem cells (MSCs) into adipocytes offers a good model for such an analysis. The aim of this study was to quantify eight intracellular and extracellular miRNAs (miR-21a, miR-26b, miR-30a, miR-92a, miR-146a, miR-148a, miR-199, and miR-383a) during porcine in vitro adipogenesis using droplet digital PCR (ddPCR), a highly sensitive method. It was found that only some miRNAs associated with the inflammatory process (miR-21a, miR-92a) were highly expressed in differentiated adipocytes and were also secreted by cells. All miRNAs associated with adipocyte differentiation were highly abundant in both the studied cells and in the cell culture medium. Those miRNAs showed a characteristic expression profile with upregulation during differentiation.

Emerging role of exosomes in vascular diseases

Exosomes are biological small spherical lipid bilayer vesicles secreted by most cells in the body. Their contents include nucleic acids, proteins, and lipids. Exosomes can transfer material molecules between cells and consequently have a variety of biological functions, participating in disease development while exhibiting potential value as biomarkers and therapeutics. Growing evidence suggests that exosomes are vital mediators of vascular remodeling. Endothelial cells (ECs), vascular smooth muscle cells (VSMCs), inflammatory cells, and adventitial fibroblasts (AFs) can communicate through exosomes; such communication is associated with inflammatory responses, cell migration and proliferation, and cell metabolism, leading to changes in vascular function and structure. Essential hypertension (EH), atherosclerosis (AS), and pulmonary arterial hypertension (PAH) are the most common vascular diseases and are associated with significant vascular remodeling. This paper reviews the latest research progress on the involvement of exosomes in vascular remodeling through intercellular information exchange and provides new ideas for understanding related diseases.

Precise profiling of exosomal biomarkers via programmable curved plasmonic nanoarchitecture-based biosensor for clinical diagnosis of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease of complex pathogenesis, with overt symptoms following disease progression. Early AD diagnosis is challenging due to the lack of robust biomarkers and limited patient access to diagnostics via neuroimaging and cerebrospinal fluid (CSF) tests. Exosomes present in body fluids are attracting attention as diagnostic biomarkers that directly reflect neuropathological features within the brain. In particular, exosomal miRNAs (exomiRs) signatures are involved in AD pathogenesis, showing a different expression between patients and the healthy controls (HCs). However, low yield and high homologous nature impede the accuracy and reproducibility of exosome blood-based AD diagnostics. Here, we developed a programmable curved plasmonic nanoarchitecture-based biosensor to analyze exomiRs in clinical serum samples for accurate AD diagnosis. To allow the detection of exomiRs in serum at attomolar levels, nanospaces (e.g., nanocrevice and nanocavity) were introduced into the nanostructures to dramatically increase the spectral sensitivity by adjusting the bending angle of the plasmonic nanostructure through sodium chloride concentration control. The developed biosensor classifies individuals into AD, mild cognitive impairment (MCI) patients, and HCs through profiling and quantifying exomiRs. Furthermore, integrating analysis expression patterns of multiple exosomal biomarkers improved serum-based diagnostic performance (average accuracy of 98.22%). Therefore, precise, highly sensitive serum-derived exosomal biomarker detection-based plasmonic biosensor has a robust capacity to predict the molecular pathologic of neurodegenerative disease, progression of cognitive decline, MCI/AD conversion, as well as early diagnosis and treatment.

Analysis of miR-203a-3p/SOCS3-mediated induction of M2 macrophage polarization to promote diabetic wound healing based on epidermal stem cell-derived exosomes

BACKGROUND

The development of therapeutic strategies to improve wound healing in individual diabetic patients remains challenging. Stem cell-derived exosomes represent a promising nanomaterial, and microRNAs (miRNAs) can be isolated from them. It is important to identify the potential therapeutic role of specific miRNAs, given that miRNAs can play a therapeutic role.

METHODS

qPCR, flow cytometry, and western blotting were used to verify the effect of epidermal stem cell-derived exosomes (EpiSC-EXOs) on M2 macrophage polarization and SOCS3 expression. By screening key miRNAs targeting SOCS3 in EpiSC-EXOs by high-throughput sequencing, we verified the mechanism in vitro. Finally, an animal model was used to verify the effect of promoting healing.

RESULTS

The use of EpiSC-EXOs reduced SOCS3 expression and promoted M2 macrophage polarization. The abundant miR-203a-3p present in the EpiSC-EXOs specifically bound to SOCS3 and activated the JAK2/STAT3 signaling pathway to induce M2 macrophage polarization. Treatment of the db/db mouse wound model with miR-203a-3p agomir exerted a pro-healing effect.

CONCLUSIONS

Our results demonstrated that the abundant miR-203a-3p present in EpiSC-EXOs can promote M2 macrophage polarization by downregulating SOCS3 and suggested that diabetic wounds can obtain better healing effects through this mechanism.

Real-Time Dissection of the Transportation and miRNA-Release Dynamics of Small Extracellular Vesicles

Extracellular vesicles (EVs) are cell-derived membrane-enclosed structures that deliver biomolecules for intercellular communication. Developing visualization methods to elucidate the spatiotemporal dynamics of EVs' behaviors will facilitate their understanding and translation. With a quantum dot (QD) labeling strategy, a single particle tracking (SPT) platform is proposed here for dissecting the dynamic behaviors of EVs. The interplays between tumor cell-derived small EVs (T-sEVs) and endothelial cells (ECs) are specifically investigated based on this platform. It is revealed that, following a clathrin-mediated endocytosis by ECs, T-sEVs are transported to the perinuclear region in a typical three-stage pattern. Importantly, T-sEVs frequently interact with and finally enter lysosomes, followed by quick release of their carried miRNAs. This study, for the first time, reports the entire process and detailed dynamics of T-sEV transportation and cargo-release in ECs, leading to better understanding of their proangiogenic functions. Additionally, the QD-based SPT technique will help uncover more secrets of sEV-mediated cell-cell communication.

Systemic circulating microRNA landscape in Lynch syndrome

Circulating microRNAs (c-miRs) are small noncoding RNA molecules that migrate throughout the body and regulate gene expression. Global c-miR expression patterns (c-miRnomes) change with sporadic carcinogenesis and have predictive potential in early detection of cancers. However, there are no studies that have assessed whether c-miRnomes display similar potential in carriers of inherited pathogenic mismatch-repair gene variants (path_MMR), known as Lynch syndrome (LS), who are predisposed to highly increased cancer risk. Using high-throughput sequencing and bioinformatic approaches, we conducted an exploratory analysis to characterize systemic c-miRnomes of path_MMR carriers, sporadic rectal cancer patients and non-LS controls. We showed for the first time that cancer-free path_MMR carriers have a systemic c-miRnome of 40 differentially expressed c-miRs that can distinguish them from non-LS controls. The systemic c-miRnome of cancer-free path_MMR carriers also resembles the systemic c-miRnomes of cancer patients with or without path_MMR. Our pathway analysis linked the found differentially expressed c-miRs to carcinogenesis. A total of 508 putative target genes were identified for 32 out of 40 differentially expressed c-miRs, and 238 of them were enriched in cancer-related pathways. The most enriched c-miR-target genes include well-known oncogenes and tumor suppressor genes such as BCL2, AKT3, PIK3CA, KRAS, NRAS, CDKN1A and PIK3R1. Taken together, our findings suggest that LS and sporadic carcinogenesis share common biological pathways and alterations in these pathways can produce a c-miR signature which can track potential oncogenic stress in cancer-free path_MMR carriers. Therefore, c-miRs hold potential in monitoring the LS risk stratification patterns during clinical surveillance or cancer management.

Liposome fusogenic enzyme-free circuit enables high-fidelity determination of single exosomal RNA

Accurate determination of single exosomal inclusions in situ presents a significant challenge due to their extremely low abundance as well sub-100 nm vesicle dimensions. Here, we created a Liposome Fusogenic Enzyme-free circuit (LIFE) approach for the high-fidelity identification of exosome-encapsulated cargoes without destroying the vesicle integrity. The probe-loaded cationic fusogenic liposome could capture and fuse with a single target exosome, enabling probes delivery and target biomolecule-initiated cascaded signal amplification in situ. Then the DNAzyme probe encountered conformal change upon exosomal microRNA activation, and generated a convex DNAzyme structure to cleave the RNA site of substrate probe. After that, the target microRNA could be released to introduce a cleavage cycle to yield amplified fluorescence readout. Therefore, trace cargoes in a single exosome could be accurately determined by elaborately controlling the ratio of introduced LIFE probe, paving the way toward the exploration of a universal sensing platform for the assessment of exosomal cargoes to facilitate early disease diagnosis and personalized treatment.

Potential Role of Circulating miRNAs for Breast Cancer Management in the Neoadjuvant Setting: A Road to Pave

Recently, circulating microRNAs (miRNAs) have emerged as potential non-invasive biomarkers for breast cancer (BC) management. In the context of BC patients undergoing neoadjuvant chemotherapy (NAC), the possibility of obtaining repeated, non-invasive biological samples from patients before, during, and after treatment is incredibly convenient and provides the opportunity to investigate circulating miRNAs as diagnostic, predictive, and prognostic tools. The present review aims to summarize major findings in this setting, thus highlighting their potential applicability in daily clinical practice and their possible limitations. In all the contexts (diagnostic, predictive, and prognostic), circulating miR-21-5p and miR-34a-5p have emerged as the most promising non-invasive biomarkers for BC patients undergoing NAC. Specifically, their high baseline level could discriminate between BC patients and healthy controls. On the other hand, in predictive and prognostic investigations, low circulating miR-21-5p and miR-34a-5p levels may identify patients with better outcomes, in terms of both treatment response and invasive disease-free survival. However, the findings in this field have been very heterogeneous. Indeed, pre-analytical and analytical variables, as well as factors related to patients, may explain the inconsistency among different study results. Thus, further clinical trials, with more precise patient inclusion criteria and more standardized methodological approaches, are definitely needed to better define the potential role of these promising non-invasive biomarkers.

Kinetics-accelerated one-step detection of MicroRNA through spatially localized reactions based on DNA tile self-assembly

The localization of isothermal amplification systems has elicited extensive attention due to the enhanced reaction kinetics when detecting ultra-trace small-molecule nucleic acids. Therefore, the seek for an appropriate localization cargo of spatially confined reactions is urgent. Herein, we have developed a novel approach to localize the catalytic hairpin assembly (CHA) system into the DNA tile self-assembly nanostructure. Thanks to the precise programming and robust probe loading capacity, this strategy achieved a 2.3 × 10⁵-fold higher local reaction concentration than a classical CHA system with enhanced reaction kinetics in theory. From the experimental results, this strategy could reach the reaction plateau faster and get access to a magnified effect of 1.57-6.99 times higher in the linear range of microRNA (miRNA) than the simple CHA system. Meanwhile, this strategy satisfied the demand for the one-step detection of miRNA in cell lysates at room temperature with good sensitivity and specificity. These features indicated its excellent potential for ultra-trace molecule detection in clinical diagnosis and provided new insights into the field of bioassays based on DNA tile self-assembly nanotechnology.

Targeting Non-Coding RNA for CNS Injuries: Regulation of Blood-Brain Barrier Functions

Central nervous system (CNS) injuries are the most common cause of death and disability around the world. The blood-brain barrier (BBB) is located at the interface between the CNS and the surrounding environment, which protects the CNS from exogenous molecules, harmful agents or microorganisms in the blood. The disruption of BBB is a common feature of CNS injuries and participates in the pathological processes of secondary brain damage. Recently, a growing number of studies have indicated that non-coding RNAs (ncRNAs) play an important role in brain development and are involved in CNS injuries. In this review, we summarize the mechanisms of BBB breakdown after CNS injuries. We also discuss the effects of ncRNAs including long noncoding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) on BBB damage in CNS injuries such as ischemic stroke, traumatic brain injury (TBI), intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH). In addition, we clarify the pharmacotherapies that could regulate BBB function via ncRNAs in CNS injuries, as well as the challenges and perspectives of ncRNAs on modulation of BBB function. Hence, on the basis of these effects, ncRNAs may be developed as therapeutic agents to protect the BBB for CNS injury patients.

Altered microRNA Transcriptome in Cultured Human Airway Cells upon Infection with SARS-CoV-2

Numerous proteomic and transcriptomic studies have been carried out to better understand the current multi-variant SARS-CoV-2 virus mechanisms of action and effects. However, they are mostly centered on mRNAs and proteins. The effect of the virus on human post-transcriptional regulatory agents such as microRNAs (miRNAs), which are involved in the regulation of 60% of human gene activity, remains poorly explored. Similar to research we have previously undertaken with other viruses such as Ebola and HIV, in this study we investigated the miRNA profile of lung epithelial cells following infection with SARS-CoV-2. At the 24 and 72 h post-infection time points, SARS-CoV-2 did not drastically alter the miRNome. About 90% of the miRNAs remained non-differentially expressed. The results revealed that miR-1246, miR-1290 and miR-4728-5p were the most upregulated over time. miR-196b-5p and miR-196a-5p were the most downregulated at 24 h, whereas at 72 h, miR-3924, miR-30e-5p and miR-145-3p showed the highest level of downregulation. In the top significantly enriched KEGG pathways of genes targeted by differentially expressed miRNAs we found, among others, MAPK, RAS, P13K-Akt and renin secretion signaling pathways. Using RT-qPCR, we also showed that SARS-CoV-2 may regulate several predicted host mRNA targets involved in the entry of the virus into host cells (ACE2, TMPRSS2, ADAM17, FURIN), renin-angiotensin system (RAS) (Renin, Angiotensinogen, ACE), innate immune response (IL-6, IFN1β, CXCL10, SOCS4) and fundamental cellular processes (AKT, NOTCH, WNT). Finally, we demonstrated by dual-luciferase assay a direct interaction between miR-1246 and ACE-2 mRNA. This study highlights the modulatory role of miRNAs in the pathogenesis of SARS-CoV-2.

The novel importance of miR-143 in obesity regulation

Obesity and substantially increased risk of metabolic diseases have become a global epidemic. microRNAs have attracted a great deal of attention as a potential therapeutic target for obesity. MiR-143 has been known to specifically promote adipocyte differentiation by downregulating extracellular signal-regulated kinase 5. Our latest study found that miR-143 knockout is against diet-induced obesity by promoting brown adipose tissue thermogenesis and inhibiting white adipose tissue adipogenesis. Moreover, LPS- or IL-6-induced inhibition of miR-143 expression in brown adipocytes promotes thermogenesis by targeting adenylate cyclase 9. In this review, we will summarize the expression and functions of miR-143 in different tissues, the influence of obesity on miR-143 in various tissues, the important role of adipose-derived miR-143 in the development of obesity, the role of miR-143 in immune cells and thermoregulation and discuss the potential significance and application prospects of miR-143 in obesity management.

Blood orange juice intake modulates plasma and PBMC microRNA expression in overweight and insulin-resistant women: impact on MAPK and NFκB signaling pathways

Blood orange consumption presents potential health benefits and may modulate epigenetic mechanisms such as microRNAs (miRNAs) expression. MiRNAs are non-coding RNAs responsible for post-transcriptional gene regulation, and these molecules can also be used as biomarkers in body fluids. This study was designed to investigate the effect of chronic blood orange juice (BOJ) intake on the inflammatory response and miRNA expression profile in plasma and blood cells in overweight women. The study cohort was comprised of twenty women aged 18-40 years old, diagnosed as overweight, who consumed 500 mL/d of BOJ for four weeks. Clinical data were collected at baseline and after 4 weeks of juice consumption, e.g., anthropometric and hemodynamic parameters, food intake, blood cell count, and metabolic and inflammatory biomarkers. BOJ samples were analyzed and characterized. Additionally, plasma and blood cells were also collected for miRNA expression profiling and evaluation of the expression of genes and proteins in the MAPK and NFκB signaling pathways. BOJ intake increased the expression of miR-144-3p in plasma and the expression of miR-424-5p, miR-144-3p, and miR-130b-3p in peripheral blood mononuclear cells (PBMC). Conversely, the beverage intake decreased the expression of let-7f-5p and miR-126-3p in PBMC. Computational analyses identified different targets of the dysregulated miRNA on inflammatory pathways. Furthermore, BOJ intake increased vitamin C consumption and the pJNK/JNK ratio and decreased the expression of IL6 mRNA and NFκB protein. These results demonstrate that BOJ regulates the expression of genes involved in the inflammatory process and decreases NFкB-protein expression in PBMC.

Extracellular Vesicles as Carriers of Adipokines and Their Role in Obesity

Extracellular vesicles (EVs) have lately arisen as new metabolic players in energy homeostasis participating in intercellular communication at the local and distant levels. These nanosized lipid bilayer spheres, carrying bioactive molecular cargo, have somehow changed the paradigm of biomedical research not only as a non-classic cell secretion mechanism, but as a rich source of biomarkers and as useful drug-delivery vehicles. Although the research about the role of EVs on metabolism and its deregulation on obesity and associated pathologies lagged slightly behind other diseases, the knowledge about their function under normal and pathological homeostasis is rapidly increasing. In this review, we are focusing on the current research regarding adipose tissue shed extracellular vesicles including their characterization, size profile, and molecular cargo content comprising miRNAs and membrane and intra-vesicular proteins. Finally, we will focus on the functional aspects attributed to vesicles secreted not only by adipocytes, but also by other cells comprising adipose tissue, describing the evidence to date on the deleterious effects of extracellular vesicles released by obese adipose tissue both locally and at the distant level by interacting with other peripheral organs and even at the central level.

Overexpression of miR-148a-3p inhibits extracellular matrix degradation and alleviates IL-1β-induced intervertebral disc degeneration

Objectives

Recently, studies on microRNAs (miRNAs) and their targets and related genes have provided new therapeutic opportunities for controlling intervertebral disc degeneration (IDD). We aimed to investigate the effects of miR-148a-3p overexpression on IDD progression.

Materials and Methods

This study used microRNA microarrays to analyze key regulators of IDD. Q-PCR was used to verify the IL-1β-induced down-regulation of miR-148a-3p expression both in nucleus pulposus (NP) tissues of IDD patients and in degenerated NP cells (NPCs) of rats. Rat NPC micromass cultures and ex vivo intervertebral disc (IVD) culture models were established, and histological staining was performed to verify the effect of miR-148a-3p on the general morphology and proteoglycan and collagen contents of IVDs. In addition, q-PCR and western blotting analyses were performed to examine the expression of ECM molecules and matrix-degrading enzymes. A luciferase reporter assay was used to confirm the target genes of miR-148a-3p.

Results

Our data revealed that miR-148a-3p was down-regulated in IDD. Overexpression of miR-148a-3p had no effect on ACAN or COL2A1 gene expression but decreased MMP3, MMP13, and ADAMTS5 gene expression. The matrix deposited by miR-148a-3p-overexpressing rat NPCs contained high levels of proteoglycans and collagen. The ex vivo experiments verified that agomiR-148a-3p alleviated the NPC matrix degradation induced by IL-1β. A luciferase reporter assay confirmed that miR-148a-3p directly targeted ADAMTS5 and MMP13.

Conclusion

We proved that miR-148a-3p can attenuate ECM loss and protect NP function by inhibiting matrix-degrading enzymes.

p53 and HuR combinatorially control the biphasic dynamics of microRNA-125b in response to genotoxic stress

Post-transcriptional regulation of p53, by the microRNA miR-125b and the RNA-binding protein HuR, controls p53 expression under genotoxic stress. p53 mRNA translation is repressed by miR-125b, tightly regulating its basal level of expression. The repression is relieved upon DNA damage by a decrease in miR-125b level, contributing to pulsatile expression of p53. The pulse of p53, as also of HuR, in response to UV irradiation coincides with a time-dependent biphasic change in miR-125b level. We show that the cause for the decrease in miR-125b level immediately post DNA-damage is enhanced exosomal export mediated by HuR. The subsequent increase in miR-125b level is due to p53-mediated transcriptional upregulation and enhanced processing, demonstrating miR-125b as a transcriptional and processing target of p53. p53 activates the transcription of primary miR-125b RNA from a cryptic promoter in response to UV irradiation. Together, these regulatory processes constitute reciprocal feedback loops that determine the biphasic change in miR-125b level, ultimately contributing to the fine-tuned temporal regulation of p53 expression in response to genotoxic stress.

The updated development of blood-based biomarkers for Huntington's disease

Huntington's disease is a progressive neurodegenerative disease caused by mutation of the huntingtin (HTT) gene. The identification of mutation carriers before symptom onset provides an opportunity to intervene in the early stage of the disease course. Optimal biomarkers are of great value to reflect neuropathological and clinical progression and are sensitive to potential disease-modifying treatments. Blood-based biomarkers have the merits of minimal invasiveness, low cost, easy accessibility and safety. In this review, we summarized the updated development of blood-based biomarkers for HD from six aspects, including neuronal injuries, oxidative stress, endocrine functions, immune reactions, metabolism and differentially expressed miRNAs. The blood-based biomarkers presented and discussed in this review were close to clinical applicability and might facilitate clinical design as surrogate endpoints. Exploration and validation of robust blood-based biomarkers require further standard and systemic study design in the future.

Exosomes treating osteoarthritis: hope with challenge

Osteoarthritis (OA) has been proven as the second primary cause of pain and disability in the elderly population, impact patients both physically and mentally, as well as imposing a heavy burden on the global healthcare system. Current treatment methods, whether conservative or surgical, that aim at relieving symptoms can not delay or reverse the degenerative process in the structure. Scientists and clinicians are facing a revolution in OA treatment strategies. The emergence of exosomes brings hope for OA treatment based on pathology, which is attributed to its full potential in protecting chondrocytes from excessive death, alleviating inflammation, maintaining cartilage matrix metabolism, and regulating angiogenesis and subchondral bone remodeling. Therefore, we summarized the recent studies of exosomes in OA, aiming to comprehensively understand the functions and mechanisms of exosomes in OA treatment, which may provide direction and theoretical support for formulating therapeutic strategies in the future.

Increased extracellular release of microRNAs from dorsal root ganglion cells in a rat model of neuropathic pain caused by peripheral nerve injury

microRNAs (miRNAs) are extracellularly released by cells for intercellular communication, while intracellularly, they inhibit the expression of specific genes. An increasing number of studies suggest that extracellular miRNAs have great potential as both therapeutic targets and disease-specific biomarkers in a variety of diseases, including pain disorders. However, little is known about miRNA release from dorsal root ganglion (DRG) neurons in neuropathic pain caused by peripheral nerve injury. In this study, we investigated the changes in the extracellular release of miRNAs from DRG neurons in a rat model of neuropathic pain induced by chronic constriction injury of the sciatic nerve. We found increased release of six miRNAs (let-7d, miR-21, miR-142-3p, miR-146b, miR-203-3p and miR-221) from primary cultured DRG neurons prepared from rats 7 days after nerve injury. Among these, miR-221 was also increased in serum from days 7 to 28 after nerve injury. In contrast, serum miR-221 levels and its release from DRG neurons were unchanged in an inflammatory pain model produced by intraplantar injection of complete Freund's adjuvant. These results suggest that the increased release of specific miRNAs by DRG neurons may be involved in the pathophysiology of neuropathic pain through extracellular as well as intracellular mechanisms. Furthermore, serum miR-221 may be useful as a biomarker of neuropathic pain caused by peripheral nerve injury.

Analysis of Differentially Expressed MicroRNAs in Serum and Lung Tissues from Individuals with Severe Asthma Treated with Oral Glucocorticoids

Nowadays, microRNAs (miRNAs) are increasingly used as biomarkers due to their potential contribution to the diagnosis and targeted treatment of a range of diseases. The aim of the study was to analyze the miRNA expression profiles in serum and lung tissue from patients with severe asthma treated with oral corticosteroids (OCS) and those without OCS treatment. For this purpose, serum and lung tissue miRNAs of OCS and non-OCS asthmatic individuals were evaluated by miRNAs-Seq, and subsequently miRNA validation was performed using RT-qPCR. Additionally, pathway enrichment analysis of deregulated miRNAs was conducted. We observed altered expression by the next-generation sequencing (NGS) of 11 miRNAs in serum, of which five (hsa-miR-148b-3p, hsa-miR-221-5p, hsa-miR-618, hsa-miR-941, and hsa-miR-769-5p) were validated by RT-qPCR, and three miRNAs in lung tissue (hsa-miR-144-3p, hsa-miR-144-5p, and hsa-miR-451a). The best multivariate logistic regression model to differentiate individuals with severe asthma, treated and untreated with OCS, was to combine the serum miRNAs hsa-miR-221-5p and hsa-miR-769-5p. Expression of hsa-miR-148b-3p and hsa-miR-221-5p correlated with FEV1/FVC (%) and these altered miRNAs act in key signaling pathways for asthma disease and the regulated expression of some genes (FOXO3, PTEN, and MAPK3) involved in these pathways. In conclusion, there are miRNA profiles differentially expressed in OCS-treated individuals with asthma and could be used as biomarkers of OCS treatment.