Circulating MicroRNAs as Potential Noninvasive Biomarkers of Spontaneous Intracerebral Hemorrhage

MiRNAs as potential therapeutic targets and biomarkers for non-traumatic intracerebral hemorrhage

Non-traumatic intracerebral hemorrhage (ICH) is the most common type of hemorrhagic stroke, most often occurring between the ages of 45 and 60. Hypertension is most often the cause of ICH. Less often, atherosclerosis, blood diseases, inflammatory changes in cerebral vessels, intoxication, vitamin deficiencies, and other reasons cause hemorrhages. Cerebral hemorrhage can occur by diapedesis or as a result of a ruptured vessel. This very dangerous disease is difficult to treat, requires surgery and can lead to disability or death. MicroRNAs (miRNAs) are a class of non-coding RNAs (about 18-22 nucleotides) that are involved in a variety of biological processes including cell differentiation, proliferation, apoptosis, etc., through gene repression. A growing number of studies have demonstrated miRNAs deregulation in various cardiovascular diseases, including ICH. In addition, given that computed tomography (CT) and/or magnetic resonance imaging (MRI) are either not available or do not show clear signs of possible vessel rupture, accurate and reliable analysis of circulating miRNAs in biological fluids can help in early diagnosis for prevention of ICH and prognosis patient outcome after hemorrhage. In this review, we highlight the up-to-date findings on the deregulated miRNAs in ICH, and the potential use of miRNAs in clinical settings, such as therapeutic targets and non-invasive diagnostic/prognostic biomarker tools.

Establishment of a rat model of severe spontaneous intracerebral hemorrhage

Background

Severe intracerebral hemorrhage (ICH) is the most devastating subtype of stroke resulting in high mortality and disability. At present, the development of targeted treatments to minimize the high morbidity and mortality is limited partly due to the lack of a severe ICH animal model. In this study, we aimed to establish an accurate severe ICH model in rats and examine the pathological and physiological changes associated with ICH.

Methods

A rat model of severe ICH model was established by intrastriatal injection of autologous blood using different blood volumes (ICH 100 µL group, ICH 130 µL group, ICH 160 µL group, ICH 170 µL group, and ICH 180 µL group). The mortality was assessed during the 28-day post-ICH period. Short- and long-term neurological deficits were evaluated using the Longa method, foot fault, falling latency, and Morris water maze tests. Brain water content, hematoma volume, hemoglobin content, and magnetic resonance imaging were assessed to determine the extent of brain injury. Immunofluorescence staining was conducted to examine microglial activation and neuronal apoptosis. Hematoxylin and eosin (H&E) staining, lung water content, and western blotting were used to assess lung injury following ICH.

Results

The mortality of ICH rats increased significantly with an increase in autologous blood injection. The 28-day mortality in the 100 µL, 130 µL, 160 µL, 170 µL, and 180 µL ICH groups were 5%, 20%, 40%, 75%, and 100%, respectively. A significantly higher 28-day mortality was observed in the ICH 160 µL group compared to the ICH 100 µL group. The ICH 160 µL group exhibited significantly increased neurological deficits, brain edema, hematoma volume, and hemoglobin content compared to the sham group. Compared with the sham operation group, the activation of microglia and neuronal death in ICH 160 µL rats increased. The use of H&E staining and western blotting demonstrated that disruption of the intra-alveolar structure, alveolar edema, and infiltration of inflammatory cells and cytokines into the lung tissue were more severe in the ICH 160 µL group than the sham group.

Conclusions

A severe ICH model in rats was successfully established using an injection of autologous blood at a volume of 160 µL. This model may provide a valuable tool to examine the pathological mechanisms and potential therapeutic interventions of severe ICH.

MiRNAs and Their Role in Venous Thromboembolic Complications

Venous thromboembolic complications (VTCs), which include deep vein thrombosis (DVT) and pulmonary embolism (PE), have remained a pressing problem in modern clinical medicine for a long time. Despite the already wide arsenal of modern methods for diagnosing and treating this disease, VTCs rank third in the structure of causes of death among all cardiovascular diseases, behind myocardial infarction (MI) and ischemic stroke (IS). Numerous studies have confirmed the importance of understanding the molecular processes of VTCs for effective therapy and diagnosis. Significant progress has been made in VTC research in recent years, where the relative contribution of microRNAs (miRNAs) in the mechanism of thrombus formation and their consideration as therapeutic targets have been well studied. In this case, accurate, timely, and as early as possible diagnosis of VTCs is of particular importance, which will help improve both short-term and long-term prognoses of patients. This case accounts for the already well-studied circulating miRNAs as non-invasive biomarkers. This study presents currently available literature data on the role of miRNAs in VTCs, revealing their potential as therapeutic targets and diagnostic and prognostic tools for this terrible disease.

BCL-3 Promotes Intracerebral Hemorrhage Progression by Increasing Blood-Brain Barrier Permeability, Inflammation, and Cell Apoptosis via Endoplasmic Reticulum Stress

Background

Intracerebral hemorrhage (ICH) is among the common types of stroke with high mortality and morbidity. Molecular biomarker selection is crucial for ICH diagnosis and treatment. However, the identification of ICH-related biomarkers remains inadequate.

Materials and Methods

In vivo and in vitro ICH models were generated and transfected with silenced B-cell lymphoma-3 (BCL-3 and siRNA BCL-3), overexpressed BCL-3, and endoplasmic reticulum stress (ERS) agonist (2-CLHA). Hematoxylin-eosin staining and transmission electron microscopy were used to observe the transfected cells. RNA sequencing was performed in vivo on the sham and ICH groups. The blood-brain barrier (BBB) permeability was evaluated by determining Evans blue dye extravasation, transendothelial electrical resistance, and paracellular permeability. Moreover, tight junction-, cell apoptosis-, and endoplasmic reticulum stress- (ERS-) related proteins were evaluated through real-time quantitative PCR, western blotting, immunohistochemistry, and TUNEL staining. The levels of inflammatory cytokines were measured through the enzyme-linked immunosorbent assay.

Results

RNA-seq revealed that BCL-3 acts as a key player. BCL-3 promotes ICH progression by increasing BBB permeability, ERS, inflammation, and cell apoptosis. Silencing of BCL-3 slows ICH progression by reducing BBB permeability and inflammation and terminating cell apoptosis and ERS in vitro and in vivo.

Conclusion

Our study identified ICH biomarkers and elucidated the role of BCL-3 in ICH for the first time.

Intracranial hemorrhage management in the multi-omics era

Intracranial hemorrhage (ICH) is a devastating disorder. Neuroprotective strategies that prevent tissue injury and improve functional outcomes have been identified in multiple animal models of ICH. However, these potential interventions in clinical trials produced generally disappointing results. With progress in omics, studies of omics data, including genomics, transcriptomics, epigenetics, proteomics, metabolomics, and the gut microbiome, may help promote precision medicine. In this review, we focused on introducing the applications of all omics in ICH and shed light on all of the considerable advantages to systematically analyze the necessity and importance of multiple omics technology in ICH.

The Role of Mitochondria-Targeting miRNAs in Intracerebral Hemorrhage

Non-traumatic intracerebral hemorrhage (ICH) is the most common type of hemorrhagic stroke, most often occurring between the ages of 45 and 60. Arterial hypertension (AH) is most often the cause of ICH, followed by atherosclerosis, blood diseases, inflammatory changes in cerebral vessels, intoxication and vitamin deficiencies. Cerebral hemorrhage can occur by diapedesis or as a result of a ruptured vessel. AH is difficult to treat, requires surgery and can lead to disability or death. One of the important directions in the study of the pathogenesis of ICH is mitochondrial dysfunction and its regulation. The key role of mitochondrial dysfunction in AH and atherosclerosis, as well as in the development of brain damage after hemorrhage, has been acknowledged. MicroRNAs (miRNAs) are a class of non-coding RNAs (about 18-22 nucleotides) that regulate a variety of biological processes including cell differentiation, proliferation, apoptosis, etc., primarily through gene repression. There is growing evidence to support dysregulated miRNAs in various cardiovascular diseases, including ICH. Further, the realization of miRNAs within mitochondrial compartment has challenged the traditional knowledge of signaling pathways involved in the regulatory network of cardiovascular diseases. However, the role of miRNAs in mitochondrial dysfunction for ICH is still under-appreciated, with comparatively much lesser studies and investigations reported, than those in other cardiovascular diseases. In this review, we summarize the up-to-date findings on the published role miRNAs in mitochondrial function for ICH, and the potential use of miRNAs in clinical settings, such as potential therapeutic targets and non-invasive diagnostic/prognostic biomarker tools.

Chrysophanol Ameliorates Hemin-Induced Oxidative Stress and Endoplasmic Reticulum Stress by Regulating MicroRNA-320-5p/Wnt3a Pathway in HT22 Cells

Oxidative stress, endoplasmic reticulum (ER) stress, and neuronal cell apoptosis have been considered as the main pathogenesis factors of brain injury after intracerebral hemorrhage (ICH). Chrysophanol (CHR) has been proved to have neuroprotective effects, but the role and underlying mechanisms of CHR in ICH remain unclear. HT22 cells were dealt with hemin to mimic an in vitro ICH model and then subjected to treatment with or without CHR. The cell viability, apoptosis, ER stress, and oxidative stress were evaluated by conducting the cell counting kit-8 (CCK-8), TdT-mediated dUTP nick end labeling (TUNEL) staining assays, western blot, and corresponding kit, respectively. Further, microRNA-sequencing, bioinformatic analysis, dual-luciferase reporter method, and rescue experiments were conducted to explore the molecular mechanisms of CHR alleviating hemin-induced ER in HT22 cell. Our data revealed that CHR increased cells viability, antiapoptosis, anti-ER stress, and antioxidative stress under conditions of hemin-induced HT22 cell injury. Mechanically, it was observed that Wnt3a was competitively sponged by miR-320-5p, and CHR activated β-catenin pathway by regulating miR-320-5p/Wnt3a molecular axis. Finally, results from the rescue experiment suggested that CHR inhibited hemin-induced cells apoptosis, ER stress, and oxidative stress through regulating the miR-320-5p/Wnt3a axis in HT22 cells. In conclusion, CHR prevented hemin-induced apoptosis, ER stress, and oxidative stress via inhibiting the miR-320-5p/Wnt3a/β-catenin pathway in HT22 cells. Our results certified that CHR could be served as a promising treatment for brain damage following ICH.

Genetics and Epigenetics of Spontaneous Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a complex and heterogeneous disease, and there is no effective treatment. Spontaneous ICH represents the final manifestation of different types of cerebral small vessel disease, usually categorized as: lobar (mostly related to cerebral amyloid angiopathy) and nonlobar (hypertension-related vasculopathy) ICH. Accurate phenotyping aims to reflect these biological differences in the underlying mechanisms and has been demonstrated to be crucial to the success of genetic studies in this field. This review summarizes how current knowledge on genetics and epigenetics of this devastating stroke subtype are contributing to improve the understanding of ICH pathophysiology and their potential role in developing therapeutic strategies.

Role of MicroRNAs and their corresponding ACE2/Apelin signaling pathways in hypertension

Hypertension is controlled via the alteration of microRNAs (miRNAs), their therapeutic targets angiotensin II type I receptor (AT1R) and cross talk of signaling pathways. The stimulation of the Ang II/AT1R pathway by deregulation of miRNAs, has also been linked to cardiac remodeling as well as the pathophysiology of high blood pressure. As miRNAs have been associated to ACE2/Apelin and Mitogen-activated protein kinases (MAPK) signaling, it has revealed an utmost protective impact over hypertension and cardiovascular system. The ACE2-coupled intermodulation between RAAS, Apelin system, MAPK signaling pathways, and miRNAs reveal the practicalities of high blood pressure. The research of miRNAs may ultimately lead to the expansion of an innovative treatment strategy for hypertension, which indicates the need to explore them further at the molecular level. Therefore, here we have focused on the mechanistic importance of miRNAs in hypertension, ACE2/Apelin signaling as well as their biological functions, with a focus on interplay and crosstalk between ACE2/Apelin signaling, miRNAs, and hypertension, and the progress in miRNA-based diagnostic techniques with the goal of facilitating the development of new hypertension-controlling therapeutics.

Differential non-coding RNAs expression profiles of invasive and non-invasive pituitary adenomas

BACKGROUND

Pituitary adenoma (PA) accounts for 10-15% of all intracranial neoplasms. Despite their benign nature, PA often shows invasive growth. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are a class of non-coding RNAs that play important roles in PA initiation and progression.

AIM

The aim of this study was to find specific profiles of miR-200a and long non-coding RNA (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) in PA based on a comparative study using Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analyses of tumor tissue and plasma.

METHODS

Plasma and PA tissue samples were obtained from two groups of included patients (15 invasive and 15 non-invasive PA). In addition, plasma samples from patients with invasive PA have collected pre- and post-operation. Plasma and tissue samples subjected to qRT-PCR analyses for the expression levels of miR-200a and lncRNA ANRIL.

RESULTS

The expression levels of miR-200a and lncRNA ANRIL were increased in tissue samples patients with invasive PA than in the patients with non-invasive PA. In addition, the expression levels of circulating miR-200a and lncRNA ANRIL were increased in patients with invasive PA than in patients with non-invasive PA in the pre-operation period. However, the expression level of plasma circulating miR-200a and lncRNA ANRIL was decreased in patients with invasive PA in the post-operation period. Our results depicted a miR-200a and lncRNA ANRIL expression in tissue and plasma samples in the patients with invasive PA. In addition, Receiver Operating Characteristic (ROC) curve was used to evaluate the diagnostic value of these circulating miR-200a and lncRNA ANRIL.

CONCLUSION

The expression of these tumor-associated ncRNAs has been elevated in the PAs. Therefore, miR-200a and lncRNA ANRIL represents as biomarkers for diagnosis and potential targets for novel invasive PA treatment strategies.

Dysregulation of microRNA and Intracerebral Hemorrhage: Roles in Neuroinflammation

Intracerebral hemorrhage (ICH) is a major public health problem and devastating subtype of stroke with high morbidity and mortality. Notably, there is no effective treatment for ICH. Neuroinflammation, a pathological hallmark of ICH, contributes to both brain injury and repair and hence, it is regarded as a potential target for therapeutic intervention. Recent studies document that microRNAs, small non-coding RNA molecules, can regulate inflammatory brain response after ICH and are viable molecular targets to alter brain function. Therefore, there is an escalating interest in studying the role of microRNAs in the pathophysiology of ICH. Herein, we provide, for the first time, an overview of the microRNAs that play roles in ICH-induced neuroinflammation and identify the critical knowledge gap in the field, as it would help design future studies.

lncRNA MEG3 Downregulation Relieves Intracerebral Hemorrhage by Inhibiting Oxidative Stress and Inflammation in an miR-181b-Dependent Manner

BACKGROUND This study was designed to illustrate the effects and latent mechanism of lncRNA maternally expressed gene 3 (MEG3) on intracerebral hemorrhage (ICH)-induced brain injury. MATERIAL AND METHODS An ICH rat model was generated to determine the role of lncRNA MEG3 in ICH. The interaction between lncRNA MEG3 and microRNA (miR)-181b were confirmed by Starbase and dual-luciferase reporter assay. One hour (h) or 3 days after ICH stimulation, rat neurological injury was evaluated by modified Neurological Severity Score (mNSS). Brain water content and cell apoptosis were assessed using brain edema assessment and flow cytometry (FCM), respectively. Caspase3 activity was also determined. Enzyme-linked immunosorbent assay (ELISA) was applied to evaluate the levels of pro-inflammatory cytokines. Moreover, the representative biomarkers of oxidative stress were evidenced using detection kits. RESULTS The lncRNA MEG3 level in ICH rat brain tissues was higher than that in the sham group. miR-181b was a direct target of lncRNA MEG3 and it was downregulated in brain tissues of ICH rats. Notably, we found that neurobehavioral scores, brain water content, and neuronal apoptosis were decreased and caspase3 activity was reduced in MEG3-shRNA-treated ICH rats, while we observed the opposite result in ICH+MEG3-shRNA+miR-181b inhibitor rats. Further analyses revealed that MEG3-shRNA inhibited inflammatory cytokines release and reduced oxidative stress. All these results were reversed by miR-181b inhibitor. In addition, MEG3-shRNA activated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway, which was reversed by miR-181b inhibitor. CONCLUSIONS MEG3-shRNA restrained oxidative stress and inflammation following ICH in an miR-181b-dependent manner.

Exosomal miR-2276-5p in Plasma Is a Potential Diagnostic and Prognostic Biomarker in Glioma

Introduction

Exosomal microRNAs (miRNAs) play an essential role in near and distant intercellular communication and are potential diagnostic and prognostic biomarkers for various cancers. This study focused on evaluation of exosomal miR-2276-5p in plasma as a diagnostic and prognostic biomarker for glioma.

Methods

Plasma exosomes from 124 patients with glioma and 36 non-tumor controls were collected and subjected to quantitative real-time polymerase chain reaction (qRT-PCR) analysis for the exosomal miR-2276-5p expression. Bioinformatic analyses were performed to identify a gene target, and CGGA and TCGA databases were checked for evaluation of prognostic relevance.

Results

The exosomal miR-2276-5p in glioma patients had a significantly decreased expression, compared with non-glioma patients (p < 0.01). Receiver operating characteristics (ROC) curve analyses were observed to regulate the diagnostic sensitivity and specificity of miR-2276-5p in glioma; the area under the curve (AUC) for miR-2276-5p was 0.8107. The lower expression of exosomal miR-2276-5p in patients with glioma correlated with poorer survival rates. RAB13 was identified as the target of miR-2276-5p which was high in glioma patients, especially those with higher tumor grades and correlated with poor survival.

Conclusion

The circulating exosomal miR-2276-5p is significantly reduced in the plasma of glioma patients, and thus, it could be a potential biomarker for patients with glioma for diagnostic and/or prognostic purposes.

New epigenetic players in stroke pathogenesis: From non-coding RNAs to exosomal non-coding RNAs

Non-coding RNAs (ncRNAs) have critical role in the pathophysiology as well as recovery after ischemic stroke. ncRNAs, particularly microRNAs, and the long non-coding RNAs (lncRNAs) are critical for angiogenesis and neuroprotection, and they have been suggested to be therapeutic, diagnostic and prognostic tools in cerebrovascular diseases, including stroke. Moreover, exosomes have been considered as nanocarriers capable of transferring various cargos, such as lncRNAs and miRNAs to recipient cells, with prominent inter-cellular roles in the mediation of neuro-restorative events following strokes and neural injuries. In this review, we summarize the pathogenic role of ncRNAs and exosomal ncRNAs in the stroke.

miR-181a Mediates Inflammatory Gene Expression After Intracerebral Hemorrhage: An Integrated Analysis of miRNA-seq and mRNA-seq in a Swine ICH Model

Intracerebral hemorrhage (ICH) is a severe neurological disorder with no proven treatment. Inflammation after ICH contributes to clinical outcomes, but the relevant molecular mechanisms remain poorly understood. In studies of peripheral leukocyte counts and mRNA-sequencing (mRNA-seq), our group previously reported that monocytes and Interleukin-8 (IL-8) were important contributors to post-ICH inflammation. microRNA (miRNA) are powerful regulators of gene expression and promising therapeutic targets. We now report findings from an integrated analysis of miRNA-seq and mRNA-seq in peripheral blood mononuclear cells (PBMCs) from a swine ICH model. In 10 pigs, one PBMC sample was collected immediately prior to ICH induction and a second 6 h later; miRNA-seq and mRNA-seq were completed for each sample. An aggregate score calculation determined which miRNA regulated the differentially expressed mRNA. Networks of molecular interactions were generated for the combined miRNA/target mRNA. A total of 227 miRNA were identified, and 46 were differentially expressed after ICH (FDR < 0.05). The anti-inflammatory miR-181a was decreased post-ICH, and it was the most highly connected miRNA in the miRNA/mRNA bioinformatic network analysis. miR-181a has interconnected pathophysiology with IL-8 and monocytes; in prior studies, we found that IL-8 and monocytes contributed to post-ICH inflammation and ICH clinical outcome, respectively. miR-181a was a significant mediator of post-ICH inflammation and is promising for further study, including as a potential therapeutic target. This investigation also demonstrated feasible methodology for miRNA-seq/mRNA-seq analysis in swine that is innovative, and with unique challenges, compared with transcriptomics research in more established species.

Identification of circular RNA expression profiles and potential biomarkers for intracerebral hemorrhage

Aim: To investigate the expression profiles of circRNAs after intracerebral hemorrhage (ICH). Materials & methods: RNA sequencing and qRT-PCR were used to investigate and validate circRNA expression levels. Bioinformatics analysis was performed to explore potential functions of the circRNAs. Results: Expression levels of 15 circRNAs were consistently altered in patients with ICH compared with their expression levels in hypertension. Three circRNAs, hsa_circ_0001240, hsa_circ_0001947 and hsa_circ_0001386, individually or combined, were confirmed as promising biomarkers for predicting and diagnosing ICH. The circRNAs were involved mainly in lysine degradation and the immune system. Conclusion: This is the first study to report expression profiles of circRNAs after ICH and to propose that three circRNAs are potential biomarkers for ICH.

iASPP protects the heart from ischemia injury by inhibiting p53 expression and cardiomyocyte apoptosis

Currently, there remains a great need to elucidate the molecular mechanism of acute myocardial infarction in order to facilitate the development of novel therapy. Inhibitor of apoptosis-stimulating protein of p53 (iASPP) is a member of the ASPP family proteins and an evolutionarily preserved inhibitor of p53 that is involved in many cellular processes, including apoptosis of cancer cells. The purpose of this study was to investigate the possible role of iASPP in acute myocardial infarction. The protein level of iASPP was markedly reduced in the ischemic hearts in vivo and hydrogen peroxide-exposed cardiomyocytes in vitro. Overexpression of iASPP reduced the infarct size and cardiomyocyte apoptosis of mice subjected to 24 h of coronary artery ligation. Echocardiography showed that cardiac function was improved as indicated by the increase in ejection fraction and fractional shortening. In contrast, knockdown of iASPP exacerbated cardiac injury as manifested by impaired cardiac function, increased infarct size, and apoptosis rate. Mechanistically, overexpression of iASPP inhibited, while knockdown of iASPP increased the expressions of p53 and Bax, the key regulators of apoptosis. Taken together, our results suggested that iASPP is an important regulator of cardiomyocyte apoptosis, which represents a potential target in the therapy of myocardial infarction.

Exosomes Derived from MicroRNA-146a-5p-Enriched Bone Marrow Mesenchymal Stem Cells Alleviate Intracerebral Hemorrhage by Inhibiting Neuronal Apoptosis and Microglial M1 Polarization

Introduction

Intracerebral hemorrhage (ICH) is a devastating type of stroke with high mortality, and the effective therapies for ICH remain to be explored. Exosomes (Exos) have been found to play important roles in cell communication by transferring molecules, including microRNAs (miRNAs/miRs). MiRNAs are critical regulators of genes involved in many various biological processes and have been demonstrated to aggravate or alleviate brain damages induced by ICH. The aim of the present study was to investigate the effect of Exos derived from miR-146a-5p-enriched bone marrow mesenchymal stem cells (BMSCs-miR-146a-5p-Exos) on experimental ICH.

Methods

ICH was induced in adult male Sprague-Dawley rats by an intrastriatal injection of collagenase type IV. At 24 h after surgery, Exos were administrated. For detecting apoptotic cells, TUNEL staining was performed using an in situ Cell Death Detection Kit. Fluoro-Jade B staining was performed to detect degenerating neurons. Immunofluorescence assay was performed to detect the expression of myeloperoxidase (MPO) and OX-42. The binding of miR-146a-5p and its target genes was confirmed by luciferase reporter assay.

Results

At 24 h after surgery, BMSCs-miR-146a-5p-Exos administration significantly improved neurological function, reduced apoptotic and degenerative neurons, and inhibited inflammatory response. Furthermore, miR-146a-5p-enriched Exos obviously inhibited the M1 polarization of microglia after ICH in rats, accompanied by the reduced expression of pro-inflammatory mediators releasing by M1 microglia including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and monocyte chemoattractant protein-1 (MCP-1). Finally, we observed that miR-146a-5p directly targeted interleukin-1 receptor-associated kinase1 (IRAK1) and nuclear factor of activated T cells 5 (NFAT5), which contributed to the inflammation response and the polarization of M1 microglia/macrophages.

Conclusion

We demonstrated that miR-146a-5p-riched BMSCs-Exos could offer neuroprotection and functional improvements after ICH through reducing neuronal apoptosis, and inflammation associated with the inhibition of microglial M1 polarization by downregulating the expression of IRAK1 and NFAT5.

The current state of MiRNAs as biomarkers and therapeutic tools

MicroRNAs (miRNAs) are non-coding RNAs with a length of 18-22 nucleotides that regulate about a third of the human genome at the post-transcriptional level. MiRNAs are involved in almost all biological processes, including cell proliferation, apoptosis, and cell differentiation, but also play a key role in the pathogenesis of many diseases. Most miRNAs are expressed within the cells themselves. Due to various forms of transport from cells like exosomes, circulating miRNAs are stable and can be found in human body fluids, such as blood, saliva, cerebrospinal fluid, and urine. Circulating miRNAs are of great interest as potential noninvasive biomarkers for tumors, lipid disorders, diabetes mellitus, and cardiovascular diseases. However, the possibility of their use in the clinic is limited, and this is associated with a number of problems since currently there are significant differences between the procedures for processing samples, methods of analysis, and especially strategies for standardizing results. Moreover, miRNAs can represent not only potential biomarkers but also become new therapeutic agents and be used in modern clinical practice, which again confirms the need for their study.