MicroRNA-27b contributes to lipopolysaccharide-mediated peroxisome proliferator-activated receptor gamma (PPARgamma) mRNA destabilization

Preclinical Alzheimer's disease shows alterations in circulating neuronal-derived extracellular vesicle microRNAs in a multiethnic cohort

INTRODUCTION

Alzheimer's disease (AD) is the leading cause of dementia, affecting around 50 million individuals worldwide. Brain-derived extracellular vesicles (EVs) can cross the blood-brain barrier carrying neuron-specific molecules, such as microRNAs (miRNAs), which have potential as biomarkers of neurodegeneration.

METHODS

We explored the association between neuronal-derived EV miRNAs from serum and AD clinical status by performing a transcriptome-wide association study involving 46 participants with clinical AD, 14 participants with preclinical AD, and 60 neurologically healthy controls.

RESULTS

We identified 14 miRNAs associated with AD risk, with more pronounced transcriptional alterations in preclinical individuals compared to clinical AD individuals. Functional analysis revealed enrichment of miRNA-target genes in neurodegenerative pathways, highlighting synuclein alpha (SNCA), cytochrome c, somatic (CYCS), and microtubule associated protein tau (MAPT) as key targets.

DISCUSSION

Our results highlight the potential role of neuronal-derived EVs in neurodegeneration and suggest avenues for further research into brain-derived biomarkers.

HIGHLIGHTS

Neuronal-derived extracellular vesicles (NDEVs) carry potential brain biomarkers. We tested the association between NDEV microRNAs (miRNAs) and Alzheimer's disease (AD). Fourteen NDEV miRNAs were associated with AD. Preclinical AD displayed more pronounced transcriptional changes than clinical AD. miRNA-target genes were enriched in pathways associated with neurodegeneration.

FAPs orchestrate homeostasis of muscle physiology and pathophysiology

As a common clinical manifestation, muscle weakness is prevalent in people with mobility disorders. Further studies of muscle weakness have found that patients with muscle weakness present with persistent muscle inflammation, loss of muscle fibers, fat infiltration, and interstitial fibrosis. Therefore, we propose the concept of muscle microenvironment homeostasis, which explains the abnormal pathological changes in muscles through the imbalance of muscle microenvironment homeostasis. And we identified an interstitial progenitor cell FAP during the transition from normal muscle microenvironment homeostasis to muscle microenvironment imbalance caused by muscle damage diseases. As a kind of pluripotent stem cell, FAPs do not participate in myogenic differentiation, but can differentiate into fibroblasts, adipocytes, osteoblasts, and chondrocytes. As a kind of mesenchymal progenitor cell, it is involved in the generation of extracellular matrix, regulate muscle regeneration, and maintain neuromuscular junction. However, the muscle microenvironment is disrupted by the causative factors, and the abnormal activities of FAPs eventually contribute to the complex pathological changes in muscles. Targeting the mechanisms of these muscle pathological changes, we have identified appropriate signaling targets for FAPs to improve and even treat muscle damage diseases. In this review, we propose the construction of muscle microenvironmental homeostasis and find the key cells that cause pathological changes in muscle after homeostasis is broken. By studying the mechanism of abnormal differentiation and apoptosis of FAPs, we found a strategy to inhibit the abnormal pathological changes in muscle damage diseases and improve muscle regeneration.

Strategies to reprogram anti-inflammatory macrophages towards pro-inflammatory macrophages to support cancer immunotherapies

Tumor-associated myeloid cells, including macrophages and myeloid-derived suppressor cells, can be highly prevalent in solid tumors and play a significant role in the development of the tumor. Therefore, myeloid cells are being considered potential targets for cancer immunotherapies. In this review, we focused on strategies aimed at targeting tumor-associated macrophages (TAMs). Most strategies were studied preclinically but we also included a limited number of clinical studies based on these strategies. We describe possible underlying mechanisms and discuss future challenges and prospects.

miRNA-Mediated Fine Regulation of TLR-Induced M1 Polarization

Macrophage polarization to the M1 spectrum is induced by bacterial cell wall components through stimulation of Toll-like family (TLR) receptors. By orchestrating the expression of relevant mediators of the TLR cascade, as well as associated pathways and feedback loops, macrophage polarization is coordinated to ensure an appropriate immune response. This is central to the successful control of pathogens and the maintenance of health. Macrophage polarization is known to be modulated at both the transcriptional and post-transcriptional levels. In recent years, the miRNA-based post-transcriptional regulation of M1 polarization has received increasing attention from the scientific community. Comparative studies have shown that TLR stimulation alters the miRNA profile of macrophages and that macrophages from the M1 or the M2 spectrum differ in terms of miRNAs expressed. Simultaneously, miRNAs are considered critical post-transcriptional regulators of macrophage polarization. In particular, miRNAs are thought to play a regulatory role in the switch between the early proinflammatory response and the resolution phase. In this review, we will discuss the current state of knowledge on the complex interaction of transcriptional and post-transcriptional regulatory mechanisms that ultimately determine the functionality of macrophages.

Circulating microRNA Profiles Identify a Patient Subgroup with High Inflammation and Severe Symptoms in Schizophrenia Experiencing Acute Psychosis

Schizophrenia is a complex and heterogenous psychiatric disorder. This study aimed to demonstrate the potential of circulating microRNAs (miRNAs) as a clinical biomarker to stratify schizophrenia patients and to enhance understandings of their heterogenous pathophysiology. We measured levels of 179 miRNA and 378 proteins in plasma samples of schizophrenia patients experiencing acute psychosis and obtained their Positive and Negative Syndrome Scale (PANSS) scores. The plasma miRNA profile revealed three subgroups of schizophrenia patients, where one subgroup tended to have higher scores of all the PANSS subscales compared to the other subgroups. The subgroup with high PANSS scores had four distinctively downregulated miRNAs, which enriched 'Immune Response' according to miRNA set enrichment analysis and were reported to negatively regulate IL-1β, IL-6, and TNFα. The same subgroup had 22 distinctively upregulated proteins, which enriched 'Cytokine-cytokine receptor interaction' according to protein set enrichment analysis, and all the mapped proteins were pro-inflammatory cytokines. Hence, the subgroup is inferred to have comparatively high inflammation within schizophrenia. In conclusion, miRNAs are a potential biomarker that reflects both disease symptoms and molecular pathophysiology, and identify a patient subgroup with high inflammation. These findings provide insights for the precision medicinal strategies for anti-inflammatory treatments in the high-inflammation subgroup of schizophrenia.

Pharmacokinetics, Pharmacodynamics, and Side Effects of Midazolam: A Review and Case Example

Midazolam, a short-acting benzodiazepine, is widely used to alleviate patient anxiety, enhance compliance, and aid in anesthesia. While its side effects are typically dose-dependent and manageable with vigilant perioperative monitoring, serious cardiorespiratory complications, including fatalities and permanent neurological impairment, have been documented. Prolonged exposure to benzodiazepines, such as midazolam, has been associated with neurological changes in infants. Despite attempts to employ therapeutic drug monitoring for optimal sedation dosing, its efficacy has been limited. Consequently, efforts are underway to identify alternative predictive markers to guide individualized dosing and mitigate adverse effects. Understanding these factors is crucial for determining midazolam's suitability for future administration, particularly after a severe adverse reaction. This article aims to elucidate the factors influencing midazolam's pharmacokinetics and pharmacodynamics, potentially leading to adverse events. Finally, a case study is presented to exemplify the complex investigation into the causative factors of midazolam-related adverse events.

Polarization of M2 Tumor-Associated Macrophages (TAMs) in Cancer Immunotherapy

We have witnessed in the last decade new milestones in the treatment of various resistant cancers with new immunotherapeutic modalities. These advances have resulted in significant objective durable clinical responses in a subset of cancer patients. These findings strongly suggested that immunotherapy should be considered for the treatment of all subsets of cancer patients. Accordingly, the mechanisms underlying resistance to immunotherapy must be explored and develop new means to target these resistant factors. One of the pivotal resistance mechanisms in the tumor microenvironment (TME) is the high infiltration of tumor-associated macrophages (TAMs) that are highly immunosuppressive and responsible, in large part, of cancer immune evasion. Thus, various approaches have been investigated to target the TAMs to restore the anti-tumor immune response. One approach is to polarize the M2 TAMS to the M1 phenotype that participates in the activation of the anti-tumor response. In this review, we discuss the various and differential properties of the M1 and M2 phenotypes, the molecular signaling pathways that participate in the polarization, and various approaches used to target the polarization of the M2 TAMs into the M1 anti-tumor phenotype. These approaches include inhibitors of histone deacetylases, PI3K inhibitors, STAT3 inhibitors, TLR agonists, and metabolic reprogramming. Clearly, due to the distinct features of various cancers and their heterogeneities, a single approach outlined above might only be effective against some cancers and not others. In addition, targeting by itself may not be efficacious unless used in combination with other therapeutic modalities.

Childhood obesity, metabolic syndrome, and oxidative stress: microRNAs go on stage

The incidence of childhood obesity and metabolic syndrome has grown notably in the last years, becoming major public health burdens in developed countries. Nowadays, oxidative stress is well-recognized to be closely associated with the onset and progression of several obesity-related complications within the framework of a complex crosstalk involving other intertwined pathogenic events, such as inflammation, insulin disturbances, and dyslipidemia. Thus, understanding the molecular basis behind these oxidative dysregulations could provide new approaches for the diagnosis, prevention, and treatment of childhood obesity and associated disorders. In this respect, the transcriptomic characterization of miRNAs bares great potential because of their involvement in post-transcriptional modulation of genetic expression. Herein, we provide a comprehensive literature revision gathering state-of-the-art research into the association between childhood obesity, metabolic syndrome, and miRNAs. We put special emphasis on the potential role of miRNAs in modulating obesity-related pathogenic events, with particular focus on oxidative stress.

Epigenetic modulations of immune cells: from normal development to tumor progression

The dysfunction of immune cell development often impairs immunological homeostasis, thus causing various human diseases. Accumulating evidence shows that the development of different immune cells from hematopoietic stem cells are highly fine-tuned by different epigenetic mechanisms including DNA methylation, histone modifications, chromatin remodeling and RNA-related regulations. Understanding how epigenetic regulators modulate normal development of immune cells contributes to the identification of new strategies for various diseases. Here, we review recent advances suggesting that epigenetic modulations can orchestrate immune cell development and functions through their impact on critical gene expression. We also discuss the aberrations of epigenetic modulations in immune cells that influence tumor progression, and the fact that underlying mechanisms affect how epigenetic drugs interfere with tumor progression in the clinic.

The role of microRNA in neuronal inflammation and survival in the post ischemic brain: a review

Each year, more than 790 000 people in the United States suffer from a stroke. Although progress has been made in diagnosis and treatment of ischemic stroke (IS), new therapeutic interventions to protect the brain during an ischemic insult is highly needed. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression post-transcriptionally. Growing evidence suggests that miRNAs have a profound impact on ischemic stroke progression and are potential targets of novel treatments. Notably, inflammatory pathways play an important role in the pathogenesis of ischemic stroke and its pathophysiologic progression. Experimental and clinical studies have illustrated that inflammatory molecular events collaboratively contribute to neuronal and glial cell survival, edema formation and regression, and vascular integrity. In the present review, we examine recent discoveries regarding miRNAs and their roles in post-ischemic stroke neuropathogenesis.

Long-Term LDL-Apheresis Treatment and Dynamics of Circulating miRNAs in Patients with Severe Familial Hypercholesterolemia

Lipoprotein apheresis (LA) is a therapeutic option for patients with severe hypercholesterolemia who have persistently elevated LDL-C levels despite attempts at drug therapy. MicroRNAs (miRNAs), important posttranscriptional gene regulators, are involved in the pathogenesis of atherosclerosis. Our study aimed to monitor the dynamics of twenty preselected circulating miRNAs in patients under long-term apheresis treatment. Plasma samples from 12 FH patients (men = 50%, age = 55.3 ± 12.2 years; mean LA overall treatment time = 13.1 ± 7.8 years) were collected before each apheresis therapy every sixth month over the course of four years of treatment. Eight complete follow-up (FU) samples were measured in each patient. Dynamic changes in the relative quantity of 6 miRNAs (miR-92a, miR-21, miR-126, miR-122, miR-26a, and miR-185; all p < 0.04) during FU were identified. Overall apheresis treatment time influenced circulating miR-146a levels (p < 0.04). In LDLR mutation homozygotes (N = 5), compared to heterozygotes (N = 7), we found higher plasma levels of miR-181, miR-126, miR-155, and miR-92a (all p < 0.03). Treatment with PCSK9 inhibitors (N = 6) affected the plasma levels of 7 miRNAs (miR-126, miR-122, miR-26a, miR-155, miR-125a, miR-92a, and miR-27a; all p < 0.04). Long-term monitoring has shown that LA in patients with severe familial hypercholesterolemia influences plasma circulating miRNAs involved in endothelial dysfunction, cholesterol homeostasis, inflammation, and plaque development. The longer the treatment using LA, the better the miRNA milieu depicting the potential cardiovascular risk.

The miRNA neuroinflammatory biomarkers in COVID-19 patients with different severity of illness

INTRODUCTION

The expression of specific miRNAs and their mRNA targets are changed in infectious disease. The aim of this study was to analyze the expression of pro-neuroinflammatory miRNAs, anti-neuroinflammatory miRNAs, and their mRNA targets in the serum of COVID-19 patients with different grades.

METHODS

COVID-19 patients with different grades were enrolled in this study and the expression of pro-neuroinflammatory miRNAs, anti-neuroinflammatory miRNAs, and their target mRNAs was analyzed by q-PCR.

RESULTS

The relative expression of anti- neuroinflammatory miRNAs (mir-21, mir-124, and mir-146a) was decreased and the relative expression of their target mRNAs (IL-12p53, Stat3, and TRAF6) was increased. Also, the relative expression of pro-neuroinflammatory miRNAs (mir-326, mir-155, and mir-27b) was increased and the relative expression of their target mRNA (PPARS, SOCS1, and CEBPA) was decreased in COVID-19 patients with increase of disease grade. A negative significant correlation was seen between mir-21 and IL-12p53 mRNA, mir-124 and Stat3 mRNA, mir-146a and TRAF6 mRNA, mir-27b and PPARS mRNA, mir-155 and SOCS1 mRNA, and between mir-326 and CEBPA mRNA in COVID-19 patients (P<0.05).

CONCLUSIONS

This study showed that the relative expression of anti- neuroinflammatory miRNAs was decreased and the relative expression of their targeted mRNAs was increased in COVID-19 patients from asymptomatic to critical illness. Also, this study showed that the relative expression of pro-neuroinflammatory miRNAs was increased and the relative expression of their targeted mRNA was decreased in COVID-19 patients from asymptomatic to critical illness.

miR-27b targets MAIP1 to mediate lipid accumulation in cultured human and mouse hepatic cells

Non-alcoholic liver disease (NAFLD) is a condition caused by excessive fat accumulation in the liver and developed via multiple pathways. miR-27b has been suggested to play crucial roles in the development of NAFLD, assuming via targeting genes involved in lipid catabolism and anabolism. However, other pathways regulated by miR-27b are largely unknown. Here we show that lipid accumulation was induced in miR-27b-transfected human and mouse hepatic cells and that knockdowns of three miR-27b-target genes, β-1,4-galactosyltransferase 3 (B4GALT3), matrix AAA peptidase interacting protein 1 (MAIP1) and PH domain and leucine rich repeat protein phosphatase 2 (PHLPP2), induced lipid accumulation. We also show that B4GALT3 and MAIP1 were direct targets of miR-27b and overexpression of MAIP1 ameliorated miR-27b-induced lipid accumulation. In addition, we show that hepatic Maip1 expression declined in mice fed a high-fat diet, suggesting the involvement of decreased Maip1 expression in the condition of fatty liver. Overall, we identified MAIP1/miR-27b axis as a mediator of hepatic lipid accumulation, a potential therapeutic target for NAFLD.

Peroxisome Proliferator-Activated Receptor-γ as a Target and Regulator of Epigenetic Mechanisms in Nonalcoholic Fatty Liver Disease

Peroxisome proliferator-activated receptor-γ (PPARγ) belongs to the superfamily of nuclear receptors that control the transcription of multiple genes. Although it is found in many cells and tissues, PPARγ is mostly expressed in the liver and adipose tissue. Preclinical and clinical studies show that PPARγ targets several genes implicated in various forms of chronic liver disease, including nonalcoholic fatty liver disease (NAFLD). Clinical trials are currently underway to investigate the beneficial effects of PPARγ agonists on NAFLD/nonalcoholic steatohepatitis. Understanding PPARγ regulators may therefore aid in unraveling the mechanisms governing the development and progression of NAFLD. Recent advances in high-throughput biology and genome sequencing have greatly facilitated the identification of epigenetic modifiers, including DNA methylation, histone modifiers, and non-coding RNAs as key factors that regulate PPARγ in NAFLD. In contrast, little is still known about the particular molecular mechanisms underlying the intricate relationships between these events. The paper that follows outlines our current understanding of the crosstalk between PPARγ and epigenetic regulators in NAFLD. Advances in this field are likely to aid in the development of early noninvasive diagnostics and future NAFLD treatment strategies based on PPARγ epigenetic circuit modification.

Exosomal miR-27b-3p secreted by visceral adipocytes contributes to endothelial inflammation and atherogenesis

Obesity, particularly increased visceral fat, positively correlates with various metabolic challenges, including atherosclerosis, but the mechanism is not fully understood. The aim of this study is to determine the role of visceral-fat-derived exosomes (Exo) in endothelial cells and atherosclerosis. We show that obesity changes the miRNA profile of visceral adipose exosomes in mice. Importantly, exosomal miR-27b-3p efficiently enters into the vascular endothelial cells and activates the NF-κB pathway by downregulating PPARα. Mechanistically, miR-27b-3p binds directly to the CDS region of PPARα mRNA, thereby promoting mRNA degradation and suppressing translation. In ApoE-deficient mice, administration of miR-27b-3p mimic increases inflammation and atherogenesis, while overexpression of PPARα protects against atherosclerosis. Thus, obesity-induced exosomal miR-27b-3p promotes endothelial inflammation and facilitates atherogenesis by PPARα suppression. We reveal an exosomal pathway by which obesity aggravates atherosclerosis and proposed therapeutic strategies for atherosclerosis in people with obesity.

Non-coding RNAs in immunoregulation and autoimmunity: Technological advances and critical limitations

Immune cell function is critically dependent on precise control over transcriptional output from the genome. In this respect, integration of environmental signals that regulate gene expression, specifically by transcription factors, enhancer DNA elements, genome topography and non-coding RNAs (ncRNAs), are key components. The first three have been extensively investigated. Even though non-coding RNAs represent the vast majority of cellular RNA species, this class of RNA remains historically understudied. This is partly because of a lag in technological and bioinformatic innovations specifically capable of identifying and accurately measuring their expression. Nevertheless, recent progress in this domain has enabled a profusion of publications identifying novel sub-types of ncRNAs and studies directly addressing the function of ncRNAs in human health and disease. Many ncRNAs, including circular and enhancer RNAs, have now been demonstrated to play key functions in the regulation of immune cells and to show associations with immune-mediated diseases. Some ncRNAs may function as biomarkers of disease, aiding in diagnostics and in estimating response to treatment, while others may play a direct role in the pathogenesis of disease. Importantly, some are relatively stable and are amenable to therapeutic targeting, for example through gene therapy. Here, we provide an overview of ncRNAs and review technological advances that enable their study and hold substantial promise for the future. We provide context-specific examples by examining the associations of ncRNAs with four prototypical human autoimmune diseases, specifically rheumatoid arthritis, psoriasis, inflammatory bowel disease and multiple sclerosis. We anticipate that the utility and mechanistic roles of these ncRNAs in autoimmunity will be further elucidated in the near future.

Advances in the research of the role of macrophage/microglia polarization-mediated inflammatory response in spinal cord injury

It is often difficult to regain neurological function following spinal cord injury (SCI). Neuroinflammation is thought to be responsible for this failure. Regulating the inflammatory response post-SCI may contribute to the recovery of neurological function. Over the past few decades, studies have found that macrophages/microglia are one of the primary effector cells in the inflammatory response following SCI. Growing evidence has documented that macrophages/microglia are plastic cells that can polarize in response to microenvironmental signals into M1 and M2 macrophages/microglia. M1 produces pro-inflammatory cytokines to induce inflammation and worsen tissue damage, while M2 has anti-inflammatory activities in wound healing and tissue regeneration. Recent studies have indicated that the transition from the M1 to the M2 phenotype of macrophage/microglia supports the regression of inflammation and tissue repair. Here, we will review the role of the inflammatory response and macrophages/microglia in SCI and repair. In addition, we will discuss potential molecular mechanisms that induce macrophage/microglia polarization, with emphasis on neuroprotective therapies that modulate macrophage/microglia polarization, which will provide new insights into therapeutic strategies for SCI.

Contribution of MicroRNA-27b-3p to Synovial Fibrotic Responses in Knee Osteoarthritis

OBJECTIVE

Synovial fibrosis contributes to osteoarthritis (OA) pathology, but the underlying mechanisms remain unknown. We have observed increased microRNA-27b-3p (miR-27b-3p) levels in synovial fluid of patients with late-stage radiographic knee OA. Here, we investigated the contribution of miR-27b-3p to synovial fibrosis in patients with severe knee OA and in a mouse model of knee OA.

METHODS

We stained synovium sections obtained from patients with radiographic knee OA scored according to the Kellgren/Lawrence scale and mice that underwent destabilization of the medial meniscus (DMM) for miR-27b-3p using in situ hybridization. We examined the effects of intraarticular injection of miR-27b-3p mimic into naive mouse knee joints and intraarticular injection of a miR-27b-3p inhibitor into mouse knee joints after DMM. We performed transfection with miR-27b-3p mimic and miR-27b-3p inhibitor in human OA fibroblast-like synoviocytes (FLS) using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) array, RNA sequencing, RT-qPCR, Western blotting, immunofluorescence, and migration assays.

RESULTS

We observed increased miR-27b-3p expression in the synovium from patients with knee OA and in mice with DMM-induced arthritis. Injection of the miR-27b-3p mimic in mouse knee joints induced a synovial fibrosis-like phenotype, increased synovitis scores, and increased COL1A1 and α-smooth muscle actin (α-SMA) expression. In the mouse model of DMM-induced arthritis, injection of the miR-27b-3p inhibitor decreased α-SMA but did not change COL1A1 expression levels or synovitis scores. Transfection with the miR-27b-3p mimic in human OA FLS induced profibrotic responses, including increased migration and expression of key extracellular matrix (ECM) genes, but transfection with the miR-27b-3p inhibitor had the opposite effects. RNA sequencing identified a PPARG/ADAMTS8 signaling axis regulated by miR-27b-3p in OA FLS. Human OA FLS transfected with miR-27b-3p mimic and then treated with the PPARG agonist rosiglitazone or with ADAMTS8 small interfering RNA exhibited altered expression of select ECM genes.

CONCLUSION

Our findings demonstrate that miR-27b-3p has a key role in ECM regulation associated with synovial fibrosis during OA.

Antiliver Fibrosis Formula of Fuzheng Huayu Alleviates Inflammatory Response

Fuzheng Huayu’s (FZHY) formula ameliorated liver fibrosis in clinical and experimental practice. Based on the close link between fibrosis and inflammation, its anti-inflammatory effect and related mechanisms were explored in this present study. With the aid of the inflammatory macrophage model, FZHY significantly blocked nitrite accumulation without observable cytotoxicity due to its suppression of inducible nitric oxide synthase (iNOS) gene and protein expressions in a concentration-depended manner. Proinflammatory mediators including IL-6, CD86, and CD40 were also restrained by FZHY. Interestingly, FZHY induced anti-inflammatory mediators heme oxygenase 1 (HO-1) and peroxisome proliferator-activated receptor γ (PPAR-γ) expressions simultaneously. Downregulation of iNOS and miR-155 and upregulation of PPAR-γ were also observed in CCl4-induced liver fibrosis mice upon FZHY administration. Mechanically, FZHY strikingly eliminated the phosphorylation of STAT1 and MAPK. Taken together, FZYH regulated the balance of proinflammatory and anti-inflammatory mediators partially via modulating STAT1/MAPK pathways and the miR-155/PPAR-γ axis.

Isoflavone daidzein ameliorates renal dysfunction and fibrosis in a postmenopausal rat model: Intermediation of angiotensin AT1 and Mas receptors and microRNAs 33a and 27a

OBJECTIVES

Chronic kidney disease (CKD), accompanied by renal dysfunction, fibrosis, and apoptosis, is highly prevalent in postmenopausal women. We tested the hypothesis that isoflavone daidzein may ameliorate renal dysfunction and fibrosis through angiotensin II type 1 (AT1R) and angiotensin 1-7 (MasR) receptors in association with microRNAs 33a and 27a.

MATERIALS AND METHODS

Two weeks before the initiation of the experiments, rats (n=84) underwent ovariectomy (OVX). Then, unilateral ureteral obstruction (UUO) was performed in OVX rats, and animals were allocated to the following groups (n=21): sham vehicle (dimethyl sulfoxide; DMSO 1%), UUO vehicle, UUO+17β-estradiol (E2), and UUO+daidzein. Each group encompassed three subgroups (n=7) treated with saline, A779 (MasR antagonist), or losartan (AT1R antagonist) for 15 days. The fractional urine excretion of sodium (FE_Na+) and potassium (FE_K+), renal failure index (RFI), renal interstitial fibrosis (RIF index), glomerulosclerosis, miR-33a, and miR-27a expressions and their target genes were analyzed. Apoptosis was measured via cleaved caspase-3 immunohistochemistry.

RESULTS

UUO increased kidney weight, FE_Na+, FE_K+, urine calcium, RFI, RIF index, glomerulosclerosis, and cleaved caspase-3. Moreover, expression of renal miR-33a and miR-27a, collagen3A1 mRNA, and protein were up-regulated post-UUO. Daidzein treatment alleviated the harmful effects of UUO especially in co-treatment with losartan. They also masked the anticipated worsening effects of A779 on UUO.

CONCLUSION

Compared with E2, daidzein efficiently ameliorated renal dysfunction, fibrosis, and apoptosis through modulation of miR-33a and miR-27a expression and their crosstalk with AT1R and MasR. Therefore, daidzein might be a promising candidate for treating CKD in postmenopausal and older women.

Bidirectional cytokine-microRNA control: A novel immunoregulatory framework in leishmaniasis

As effector innate immune cells and as a host to the protozoan parasite Leishmania, macrophages play a dual role in antileishmanial immunoregulation. The 2 key players in this immunoregulation are the macrophage-expressed microRNAs (miRNAs) and the macrophage-secreted cytokines. miRNAs, as small noncoding RNAs, play vital roles in macrophage functions including cytokines and chemokines production. In the reverse direction, Leishmania-regulated cytokines alter miRNAs expression to regulate the antileishmanial functions of macrophages. The miRNA patterns vary with the time and stage of infection. The cytokine-regulated macrophage miRNAs not only help parasite elimination or persistence but also regulate cytokine production from macrophages. Based on these observations, we propose a novel immunoregulatory framework as a scientific rationale for antileishmanial therapy.

A novel approach to type 3 diabetes mechanism: The interplay between noncoding RNAs and insulin signaling pathway in Alzheimer's disease

Today, growing evidence indicates that patients with type 2 diabetes (T2D) are at a higher risk of developing Alzheimer's disease (AD). Indeed, AD as one of the main causes of dementia in people aged more than 65 years can be aggravated by insulin resistance (IR) and other metabolic risk factors related to T2D which are also linked to the function of the brain. Remarkably, a new term called "type 3 diabetes" has been suggested for those people who are diagnosed with AD while also showing the symptoms of IR and T2D. In this regard, the role of genetic and epigenetic changes associated with AD has been confirmed by many studies. On the other hand, it should be noted that the insulin signaling pathway is highly regulated by various mechanisms, including epigenetic factors. Among these, the role of noncoding RNAs (ncRNAs), including microRNAs and long noncoding RNAs has been comprehensively studied with respect to the pathology of AD and the most well-known underlying mechanisms. Nevertheless, the number of studies exploring the association between ncRNAs and the downstream targets of the insulin signaling pathway in the development of AD has notably increased in recent years. With this in view, the present study aimed to review the interplay between different ncRNAs and the insulin signaling pathway targets in the pathogenesis of AD to find a new approach in the field of combining biomarkers or therapeutic targets for this disease.

The miR-23-27-24 cluster: an emerging target in NAFLD pathogenesis

The incidence of non-alcoholic fatty liver disease (NAFLD) is increasing globally, being the most widespread form of chronic liver disease in the west. NAFLD includes a variety of disease states, the mildest being non-alcoholic fatty liver that gradually progresses to non-alcoholic steatohepatitis, fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Small non-coding single-stranded microRNAs (miRNAs) regulate gene expression at the miRNA or translational level. Numerous miRNAs have been shown to promote NAFLD pathogenesis and progression through increasing lipid accumulation, oxidative stress, mitochondrial damage, and inflammation. The miR-23-27-24 clusters, composed of miR-23a-27a-24-2 and miR-23b-27b-24-1, have been implicated in various biological processes as well as many diseases. Herein, we review the current knowledge on miR-27, miR-24, and miR-23 in NAFLD pathogenesis and discuss their potential significance in NAFLD diagnosis and therapy.

Plasma microRNA vary in association with the progression of Alzheimer's disease

Introduction

Early intervention in Alzheimer's disease (AD) requires the development of an easily administered test that is able to identify those at risk. Focusing on microRNA robustly detected in plasma and standardizing the analysis strategy, we sought to identify disease‐stage specific biomarkers.

Methods

Using TaqMan microfluidics arrays and a statistical consensus approach, we assessed plasma levels of 185 neurodegeneration‐related microRNA, in cohorts of cognitively normal amyloid β‐positive (CN‐Aβ+), mild cognitive impairment (MCI), and Alzheimer's disease (AD) participants, relative to their respective controls.

Results

Distinct disease stage microRNA biomarkers were identified, shown to predict membership of the groups (area under the curve [AUC] >0.8) and were altered dynamically with AD progression in a longitudinal study. Bioinformatics demonstrated that these microRNA target known AD‐related pathways, such as the Phosphoinositide 3‐kinase (PI3K‐Akt) signalling pathway. Furthermore, a significant correlation was found between miR‐27a‐3p, miR‐27b‐3p, and miR‐324‐5p and amyloid beta load.

Discussion

Our results show that microRNA signatures alter throughout the progression of AD, reflect the underlying disease pathology, and may prove to be useful diagnostic markers.

MicroRNA-511-3p Mediated Modulation of the Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) Controls LPS-Induced Inflammatory Responses in Human Monocyte Derived DCs

The peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcription factor expressed in dendritic cells (DCs), where it exerts anti-inflammatory responses against TLR4-induced inflammation. Recently, microRNA-511 (miR-511) has also emerged as a key player in controlling TLR4-mediated signalling and in regulating the function of DCs. Interestingly, PPARγ has been previously highlighted as a putative target of miR-511 activity; however, the link between miR-511 and PPARγ and its influence on human DC function within the context of LPS-induced inflammatory responses is unknown. Using a selection of miR-511-3p-specific inhibitors and mimics, we demonstrate for the first time that knockdown or overexpression of miR-511-3p inversely correlates with PPARγ mRNA levels and affects its transcriptional activity following treatment with rosiglitazone (RSG; PPARγ agonist), in the presence or absence of LPS. Additionally, we show that PPARγ-mediated suppression of DC activation and pro-inflammatory cytokine production in miR-511-3p knockdown DCs is abrogated following overexpression of miR-511-3p. Lastly, PPARγ activation suppressed LPS-mediated induction of indoleamine 2,3-dioxygenase (IDO) activity in DCs, most likely due to changes in miR-511-3p expression. Our data thus suggests that PPARγ-induced modulation of DC phenotype and function is influenced by miR-511-3p expression, which may serve as a potential therapeutic target against inflammatory diseases.

Epigenetic modifications in thymic epithelial cells: an evolutionary perspective for thymus atrophy

Background

The thymic microenvironment is mainly comprised of thymic epithelial cells, the cytokines, exosomes, surface molecules, and hormones from the cells, and plays a vital role in the development, differentiation, maturation and homeostasis of T lymphocytes. However, the thymus begins to degenerate as early as the second year of life and continues through aging in human beings, leading to a decreased output of naïve T cells, the limited TCR diversity and an expansion of monoclonal memory T cells in the periphery organs. These alternations will reduce the adaptive immune response to tumors and emerging infectious diseases, such as COVID-19, also it is easier to suffer from autoimmune diseases in older people. In the context of global aging, it is important to investigate and clarify the causes and mechanisms of thymus involution.

Main body

Epigenetics include histone modification, DNA methylation, non-coding RNA effects, and chromatin remodeling. In this review, we discuss how senescent thymic epithelial cells determine and control age-related thymic atrophy, how this process is altered by epigenetic modification. How the thymus adipose influences the dysfunctions of the thymic epithelial cells, and the prospects of targeting thymic epithelial cells for the treatment of thymus atrophy.

Conclusion

Epigenetic modifications are emerging as key regulators in governing the development and senescence of thymic epithelial cells. It is beneficial to re-establish effective thymopoiesis, identify the potential therapeutic strategy and rejuvenate the immune function in the elderly.

Neuroinflammation and Its Impact on the Pathogenesis of COVID-19

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical manifestations of COVID-19 include dry cough, difficult breathing, fever, fatigue, and may lead to pneumonia and respiratory failure. There are significant gaps in the current understanding of whether SARS-CoV-2 attacks the CNS directly or through activation of the peripheral immune system and immune cell infiltration. Although the modality of neurological impairments associated with COVID-19 has not been thoroughly investigated, the latest studies have observed that SARS-CoV-2 induces neuroinflammation and may have severe long-term consequences. Here we review the literature on possible cellular and molecular mechanisms of SARS-CoV-2 induced-neuroinflammation. Activation of the innate immune system is associated with increased cytokine levels, chemokines, and free radicals in the SARS-CoV-2-induced pathogenic response at the blood-brain barrier (BBB). BBB disruption allows immune/inflammatory cell infiltration into the CNS activating immune resident cells (such as microglia and astrocytes). This review highlights the molecular and cellular mechanisms involved in COVID-19-induced neuroinflammation, which may lead to neuronal death. A better understanding of these mechanisms will help gain substantial knowledge about the potential role of SARS-CoV-2 in neurological changes and plan possible therapeutic intervention strategies.

[The miRNA neuroinflammatory biomarkers in COVID-19 patients with different severity of illness]

INTRODUCTION

The expression of specific miRNAs and their mRNA targets are changed in infectious disease. The aim of this study was to analyze the expression of pro-neuroinflammatory miRNAs, anti- neuroinflammatory miRNAs, and their mRNA targets in the serum of COVID-19 patients with different grades.

METHODS

COVID-19 patients with different grades were enrolled in this study and the expression of pro-neuroinflammatory miRNAs, anti-neuroinflammatory miRNAs, and their target mRNAs was analyzed by q-PCR.

RESULTS

The relative expression of anti- neuroinflammatory miRNAs (mir-21, mir-124, and mir-146a) was decreased and the relative expression of their target mRNAs (IL-12p53, Stat3, and TRAF6) was increased. Also, the relative expression of pro-neuroinflammatory miRNAs (mir-326, mir-155, and mir-27b) was increased and the relative expression of their target mRNA (PPARS, SOCS1, and CEBPA) was decreased in COVID-19 patients with increase of disease grade. A negative significant correlation was seen between mir-21 and IL-12p53 mRNA, mir-124 and Stat3 mRNA, mir-146a and TRAF6 mRNA, mir-27b and PPARS mRNA, mir-155 and SOCS1 mRNA, and between mir-326 and CEBPA mRNA in COVID-19 patients (P<0.05).

CONCLUSIONS

This study showed that the relative expression of anti- neuroinflammatory miRNAs was decreased and the relative expression of their targeted mRNAs was increased in COVID-19 patients from asymptomatic to critical illness. Also, this study showed that the relative expression of pro-neuroinflammatory miRNAs was increased and the relative expression of their targeted mRNA was decreased in COVID-19 patients from asymptomatic to critical illness.

α-Mangostin Alleviated Inflammation in Rats With Adjuvant-Induced Arthritis by Disrupting Adipocytes-Mediated Metabolism-Immune Feedback

A previously identified anti-rheumatic compound α-mangostin (MAN) possesses notable metabolism regulatory properties. In this study, we investigated the immune implication of MAN-altered fat metabolism on adjuvant-induced arthritis (AIA) in rats. Seven days after AIA induction, the rats received oral treatment of MAN at 50 mg/kg/day for 30 days. Metabolic indicators and basic clinical parameters were evaluated using samples collected on day 20 and 38 since immunization. Expression of nicotinamide phosphoribosyltransferase (NAMPT), sirtuin 1 (SIRT1), peroxisome proliferator activated receptor gamma (PPAR-γ), stearoyl-coa desaturase 1 (SCD-1), toll like receptor 4 (TLR4), prostaglandin-endoperoxide synthase 2 (COX-2), (p)-JNK, (p)-p65 and IL-1β were investigated by either RT-qPCR or immunobloting methods. In in vitro experiments, we treated (pre)-adipocytes with monocytes/macrophages and MAN, and investigated the changes of macrophages brought by pre-adipocytes co-culture. Generally, MAN restored the impaired fat anabolism in AIA rats, indicated by increased fat reservoir, leptin and adiponectin secretion, and PPAR-γ and SCD-1 expression. Meanwhile, it decreased circulating IL-1β and IL-6 levels, restored serological lipid profile changes, and relieved oxidative stresses, demonstrating potent therapeutic effects on AIA. AIA rats-derived monocytes inhibited mRNA PPAR-γ and SCD-1 expression in pre-adipocytes. Contrarily, MAN facilitated adipocyte differentiation in vitro, and increased free fatty acids production. It also significantly increased PPAR-γ and SCD-1 expression, which can be abrogated by PPAR-γ inhibitor T0070907. Similarly, lipopolysaccharide-primed macrophages inhibited PPAR-γ expression in the co-cultured pre-adipocytes, which was reversed by MAN. In the same co-culture system, lipopolysaccharide-induced inflammation was amplified by the co-existence of pre-adipocytes. More secretion of IL-1β and IL-6 and higher levels expression of COX-2, p-JNK, p-p65 and TLR4 were observed in lipopolysaccharide-treated macrophages when co-cultured by pre-adipocytes. The intensified inflammatory situation was eased by MAN. The treatment with pre-adipocytes culture medium achieved similar effects. Medium from lipopolysaccharide-treated adipocytes promoted IL-1β, IL-6 and MCP-1 production in separately cultured macrophages, and COX-2, p-JNK, p-p65 and TLR4 expression were increased at the meantime. MAN treatment on pre-adipocytes impaired these changes. It suggests that fat anabolism in AIA rats was deficient due to increased energy expenditure caused by inflammatory conditions. MAN restored fat metabolism homeostasis by up-regulating PPAR-γ, and reshaped secretion profile of adipocytes.

The Glitazars Paradox: Cardiotoxicity of the Metabolically Beneficial Dual PPARα and PPARγ Activation

The most common complications in patients with type-2 diabetes are hyperglycemia and hyperlipidemia that can lead to cardiovascular disease. Alleviation of these complications constitutes the major therapeutic approach for the treatment of diabetes mellitus. Agonists of peroxisome proliferator-activated receptor (PPAR) alpha and PPARγ are used for the treatment of hyperlipidemia and hyperglycemia, respectively. PPARs belong to the nuclear receptors superfamily and regulate fatty acid metabolism. PPARα ligands, such as fibrates, reduce circulating triglyceride levels, and PPARγ agonists, such as thiazolidinediones, improve insulin sensitivity. Dual-PPARα/γ agonists (glitazars) were developed to combine the beneficial effects of PPARα and PPARγ agonism. Although they improved metabolic parameters, they paradoxically aggravated congestive heart failure in patients with type-2 diabetes via mechanisms that remain elusive. Many of the glitazars, such as muraglitazar, tesaglitazar, and aleglitazar, were abandoned in phase-III clinical trials. The objective of this review article pertains to the understanding of how combined PPARα and PPARγ activation, which successfully targets the major complications of diabetes, causes cardiac dysfunction. Furthermore, it aims to suggest interventions that will maintain the beneficial effects of dual PPARα/γ agonism and alleviate adverse cardiac outcomes in diabetes.

A meta-analysis of microRNA expression profiling studies in heart failure

Heart failure (HF) is a major consequence of many cardiovascular diseases with high rate of morbidity and mortality. Early diagnosis and prevention are hampered by the lack of informative biomarkers. The aim of this study was to perform a meta-analysis of the miRNA expression profiling studies in HF to identify novel candidate biomarkers or/and therapeutic targets. A comprehensive literature search of the PubMed for miRNA expression studies related to HF was carried out. The vote counting and robust rank aggregation meta-analysis methods were used to identify significant meta-signatures of HF-miRs. The targets of HF-miRs were identified, and network construction and gene set enrichment analysis (GSEA) were performed to identify the genes and cognitive pathways most affected by the dysregulation of the miRNAs. The literature search identified forty-five miRNA expression studies related to CHF. Shared meta-signature was identified for 3 up-regulated (miR-21, miR-214, and miR-27b) and 13 down-regulated (miR-133a, miR-29a, miR-29b, miR-451, miR-185, miR-133b, miR-30e, miR-30b, miR-1, miR-150, miR-486, miR-149, and miR-16-5p) miRNAs. Network properties showed miR-29a, miR-21, miR-29b, miR-1, miR-16, miR-133a, and miR-133b have the most degree centrality. GESA identified functionally related sets of genes in signaling and community pathways in HF that are the targets of HF-miRs. The miRNA expression meta-analysis identified sixteen highly significant HF-miRs that are differentially expressed in HF. Further validation in large patient cohorts is required to confirm the significance of these miRs as HF biomarkers and therapeutic targets.

Whole transcriptome RNA-seq reveals key regulatory factors involved in type 2 diabetes pathology in peripheral fat of Asian Indians

The prevalence of Type 2 Diabetes has reached an epidemic proportion particularly in south Asian countries. We have earlier shown that the anatomical fat distribution, termed 'thin fat phenotype' in this population indeed plays a major role for their T2D-predisposition it is indeed the sick fat or adiposopathy, which is the root cause of metabolic syndrome and diabetes and affects both-peripheral, as well as visceral adipose tissue compartments. In present study, we have attempted to unravel the altered regulatory mechanisms at the level of transcription factors, and miRNAs those may likely accounts to T2D pathophysiology in femoral subcutaneous adipose tissue. We prioritized transcription factors and protein kinases as likely upstream regulators of obtained differentially expressed genes in this RNA-seq study. An inferred network of these upstream regulators was then derived and the role of TFs and miRNAs in T2D pathophysiology was explored. In conclusions, this RNS-Seq study finds that peripheral subcutaneous adipose tissue among Asian Indians show pathology characterized by altered lipid, glucose and protein metabolism, adipogenesis defect and inflammation. A network of regulatory transcription factors, protein kinases and microRNAs have been imputed which converge on the process of adipogenesis. As the majority of these genes also showed altered expression in diabetics and some of them are also circulatory, therefore they deserve further investigation for potential clinical diagnostic and therapeutic applications.

Non-coding RNA crosstalk with nuclear receptors in liver disease

The dysregulation of nuclear receptors (NRs) underlies the pathogenesis of a variety of liver disorders. Non-coding RNAs (ncRNAs) are defined as RNA molecules transcribed from DNA but not translated into proteins. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are two types of ncRNAs that have been extensively studied for regulating gene expression during diverse cellular processes. NRs as therapeutic targets in liver disease have been exemplified by the successful application of their pharmacological ligands in clinics. MiRNA-based reagents or drugs are emerging as flagship products in clinical trials. Advancing our understanding of the crosstalk between NRs and ncRNAs is critical to the development of diagnostic and therapeutic strategies. This review summarizes recent findings on the reciprocal regulation between NRs and ncRNAs (mainly on miRNAs and lncRNAs) and their implication in liver pathophysiology, which might be informative to the translational medicine of targeting NRs and ncRNAs in liver disease.

A narrative review of tumor-associated macrophages in lung cancer: regulation of macrophage polarization and therapeutic implications

Lung cancer is the deadliest malignancy worldwide. An inflammatory microenvironment is a key factor contributing to lung tumor progression. Tumor-Associated Macrophages (TAMs) are prominent components of the cancer immune microenvironment with diverse supportive and inhibitory effects on growth, progression, and metastasis of lung tumors. Two main macrophage phenotypes with different functions have been identified. They include inflammatory or classically activated (M1) and anti-inflammatory or alternatively activated (M2) macrophages. The contrasting functions of TAMs in relation to lung neoplasm progression stem from the presence of TAMs with varying tumor-promoting or anti-tumor activities. This wide spectrum of functions is governed by a network of cytokines and chemokines, cell-cell interactions, and signaling pathways. TAMs are promising therapeutic targets for non-small cell lung cancer (NSCLC) treatment. There are several strategies for TAM targeting and utilizing them for therapeutic purposes including limiting monocyte recruitment and localization through various pathways such as CCL2-CCR2, CSF1-CSF1R, and CXCL12-CXCR4, targeting the activation of TAMs, genetic and epigenetic reprogramming of TAMs to antitumor phenotype, and utilizing TAMs as the carrier for anti-cancer drugs. In this review, we will outline the role of macrophages in the lung cancer initiation and progression, pathways regulating their function in lung cancer microenvironment as well as the role of these immune cells in the development of future therapeutic strategies.

Peroxisome Proliferator-Activated Receptors (PPAR), fatty acids and microRNAs: Implications in women delivering low birth weight babies

Low birth weight (LBW) babies are associated with neonatal morbidity and mortality and are at increased risk for noncommunicable diseases (NCDs) in later life. However, the molecular determinants of LBW are not well understood. Placental insufficiency/dysfunction is the most frequent etiology for fetal growth restriction resulting in LBW and placental epigenetic processes are suggested to be important regulators of pregnancy outcome. Early life exposures like altered maternal nutrition may have long-lasting effects on the health of the offspring via epigenetic mechanisms like DNA methylation and microRNA (miRNA) regulation. miRNAs have been recognized as major regulators of gene expression and are known to play an important role in placental development. Angiogenesis in the placenta is known to be regulated by transcription factor peroxisome proliferator-activated receptor (PPAR) which is activated by ligands such as long-chain-polyunsaturated fatty acids (LCPUFA). In vitro studies in different cell types indicate that fatty acids can influence epigenetic mechanisms like miRNA regulation. We hypothesize that maternal fatty acid status may influence the miRNA regulation of PPAR genes in the placenta in women delivering LBW babies. This review provides an overview of miRNAs and their regulation of PPAR gene in the placenta of women delivering LBW babies.Abbreviations: AA - Arachidonic Acid; Ago2 - Argonaute2; ALA - Alpha-Linolenic Acid; ANGPTL4 - Angiopoietin-Like Protein 4; C14MC - Chromosome 14 miRNA Cluster; C19MC - Chromosome 19 miRNA Cluster; CLA - Conjugated Linoleic Acid; CSE - Cystathionine γ-Lyase; DHA - Docosahexaenoic Acid; EFA - Essential Fatty Acids; E2F3 - E2F transcription factor 3; EPA - Eicosapentaenoic Acid; FGFR1 - Fibroblast Growth Factor Receptor 1; GDM - Gestational Diabetes Mellitus; hADMSCs - Human Adipose Tissue-Derived Mesenchymal Stem Cells; hBMSCs - Human Bone Marrow Mesenchymal Stem Cells; HBV - Hepatitis B Virus; HCC - Hepatocellular Carcinoma; HCPT - Hydroxycamptothecin; HFD - High-Fat Diet; Hmads - Human Multipotent Adipose-Derived Stem; HSCS - Human Hepatic Stellate Cells; IUGR - Intrauterine Growth Restriction; LA - Linoleic Acid; LBW - Low Birth Weight; LCPUFA - Long-Chain Polyunsaturated Fatty Acids; MEK1 - Mitogen-Activated Protein Kinase 1; MiRNA - MicroRNA; mTOR - Mammalian Target of Rapamycin; NCDs - NonCommunicable Diseases; OA - Oleic Acid; PASMC - Pulmonary Artery Smooth Muscle Cell; PLAG1 - Pleiomorphic Adenoma Gene 1; PPAR - Peroxisome Proliferator-Activated Receptor; PPARα - PPAR alpha; PPARγ - PPAR gamma; PPARδ - PPAR delta; pre-miRNA - precursor miRNA; RISC - RNA-Induced Silencing Complex; ROS - Reactive Oxygen Species; SAT - Subcutaneous Adipose Tissue; WHO - World Health Organization.

Impaired mitochondrial function of alveolar macrophages in carbon nanotube-induced chronic pulmonary granulomatous disease

Human exposure to carbon nanotubes (CNT) has been associated with the development of pulmonary sarcoid-like granulomatous disease. Our previous studies demonstrated that multi-walled carbon nanotubes (MWCNT) induced chronic pulmonary granulomatous inflammation in mice. Granuloma formation was accompanied by decreased peroxisome proliferator-activated receptor gamma (PPARγ) and disrupted intracellular lipid homeostasis in alveolar macrophages. Others have shown that PPARγ activation increases mitochondrial fatty acid oxidation (FAO) to reduce free fatty acid accumulation. Hence, we hypothesized that the disrupted lipid metabolism suppresses mitochondrial FAO. To test our hypothesis, C57BL/6 J mice were instilled by an oropharyngeal route with 100 μg MWCNT freshly suspended in 35 % Infasurf. Control sham mice received vehicle alone. Sixty days following instillation, mitochondrial FAO was measured in permeabilized bronchoalveolar lavage (BAL) cells. MWCNT instillation reduced the mitochondrial oxygen consumption rate of BAL cells in the presence of palmitoyl-carnitine as mitochondrial fuel. MWCNT also reduced mRNA expression of mitochondrial genes regulating FAO, carnitine palmitoyl transferase-1 (CPT1), carnitine palmitoyl transferase-2 (CPT2), hydroxyacyl-CoA dehydrogenase subunit beta (HADHB), and PPARγ coactivator 1 alpha (PPARGC1A). Importantly, both oxidative stress and apoptosis in alveolar macrophages and lung tissues of MWCNT-instilled mice were increased. Because macrophage PPARγ expression has been reported to be controlled by miR-27b which is known to induce oxidative stress and apoptosis, we measured the expression of miR-27b. Results indicated elevated levels in alveolar macrophages from MWCNT-instilled mice compared to controls. Given that inhibition of FAO and apoptosis are linked to M1 and M2 macrophage activation, respectively, the expression of both M1 and M2 key indicator genes were measured. Interestingly, results showed that both M1 and M2 phenotypes of alveolar macrophages were activated in MWCNT-instilled mice. In conclusion, alveolar macrophages of MWCNT-instilled mice had increased miR-27b expression, which may reduce the expression of PPARγ resulting in attenuation of FAO. This reduction in FAO may lead to activation of M1 macrophages. The upregulation of miR-27b may also induce apoptosis, which in turn can cause M2 activation of alveolar macrophages. These observations indicate a possible role of miR-27b in impaired mitochondrial function in the chronic activation of alveolar macrophages by MWCNT and the development of chronic pulmonary granulomatous inflammation.

miR-130b-3p regulates M1 macrophage polarization via targeting IRF1

Polarized macrophages can be broadly classified into classically activated macrophages (M1) and alternatively activated macrophages (M2) in response to the microenvironment signals. Interferon regulatory factor 1 (IRF1) has been demonstrated to play a critical role in macrophage polarization. However, the mechanisms underlying the regulation of IRF1 expression in macrophage polarization still remain unclear. In this study, IRF1 expression was significantly increased in interferon-γ (IFN-γ) and lipopolysaccharide (LPS)-treated RAW264.7 cells. Moreover, miR-130b-3p was decreased and negatively associated with Irf1 in M1 macrophages. miR-130b-3p repressed M1 polarization by inhibiting IRF1 and subsequently reducing the levels of the targets of IRF1, C-C motif chemokine ligand 5 (CCL5), C-X-C motif chemokine ligand 10 (CXCL10), inducible NO synthase (iNOS), and tumor necrosis factor (TNF). Consistent with these data, overexpressed miR-130b-3p in LPS-treated mice suppressed M1 macrophage polarization in lung macrophages and peritoneal macrophages by inhibiting Irf1 expression and alleviated the inflammation in mouse lung tissues. Furthermore, the predicted binding site between the Irf1 messenger RNA 3'-untranslated region (3'-UTR) and miR-130b-3p was confirmed by the dual-luciferase reporter assay. In conclusion, our research gave the first evidence that miR-130b-3p affected the polarization of M1 macrophages by directly inhibiting Irf1. The miR-130b-3p/IRF1 pathway may be a potential target for regulating macrophage polarization.

Non-coding RNAs in cardiovascular cell biology and atherosclerosis

Atherosclerosis underlies the predominant number of cardiovascular diseases and remains a leading cause of morbidity and mortality worldwide. The development, progression and formation of clinically relevant atherosclerotic plaques involves the interaction of distinct and over-lapping mechanisms which dictate the roles and actions of multiple resident and recruited cell types including endothelial cells, vascular smooth muscle cells, and monocyte/macrophages. The discovery of non-coding RNAs (ncRNAs) including microRNAs, long non-coding RNAs, and circular RNAs, and their identification as key mechanistic regulators of mRNA and protein expression has piqued interest in their potential contribution to atherosclerosis. Accruing evidence has revealed ncRNAs regulate pivotal cellular and molecular processes during all stages of atherosclerosis including cell invasion, growth, and survival; cellular uptake and efflux of lipids, expression and release of pro- and anti-inflammatory intermediaries, and proteolytic balance. The expression profile of ncRNAs within atherosclerotic lesions and the circulation have been determined with the aim of identifying individual or clusters of ncRNAs which may be viable therapeutic targets alongside deployment as biomarkers of atherosclerotic plaque progression. Consequently, numerous in vivo studies have been convened to determine the effects of moderating the function or expression of select ncRNAs in well-characterized animal models of atherosclerosis. Together, clinicopathological findings and studies in animal models have elucidated the multifaceted and frequently divergent effects ncRNAs impose both directly and indirectly on the formation and progression of atherosclerosis. From these findings' potential novel therapeutic targets and strategies have been discovered which may pave the way for further translational studies and possibly taken forward for clinical application.

Differentially Expressed miRNA-Gene Targets Related to Intramuscular Fat in Musculus Longissimus Dorsi of Charolais × Holstein F2-Crossbred Bulls

Intramuscular fat (IMF) is a meat quality indicator associated with taste and juiciness. IMF deposition, influenced by genetic and non-genetic factors, occurs through a transcriptionally coordinated process of adipogenesis. MicroRNAs (miRNAs) are transcriptional regulators of vital biological processes, including lipid metabolism and adipogenesis. However, in bovines, limited data on miRNA profiling and association with divergent intramuscular fat content, regulated exclusively by genetic parameters, have been reported. Here, a microarray experiment was performed to identify and characterize the miRNA expression pattern in the Musculus longissimus dorsi of F₂-cross (Charolais × German Holstein) bulls with high and low IMF. A total of 38 differentially expressed miRNAs (DE miRNAs), including 33 upregulated and 5 downregulated (corrected p-value ≤ 0.05, FC ≥ ±1.2), were reported. Among DE miRNAs, the upregulated miRNAs miR-105a/b, miR-695, miR-1193, miR-1284, miR-1287-5p, miR-3128, miR-3178, miR-3910, miR-4443, miR-4445 and miR-4745, and the downregulated miRNAs miR-877-5p, miR-4487 and miR-4706 were identified as novel fat deposition regulators. DE miRNAs were further analyzed, along with previously identified differentially expressed genes (DEGs) from the same samples and predicted target genes, using multiple bioinformatic approaches, including target prediction tools and co-expression networks, as well as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. We identified DE miRNAs and their gene targets associated with bovine intramuscular adipogenesis, and we provide a basis for further functional investigations.

Xeno-miRNA in Maternal-Infant Immune Crosstalk: An Aid to Disease Alleviation

Human milk is a complex liquid that contains multifaceted compounds which provide nutrition to infants and helps to develop their immune system. The presence of secretory immunoglobulins (IgA), leucocytes, lysozyme, lactoferrin, etc., in breast milk and their role in imparting passive immunity to infants as well as modulating development of an infant's immune system is well-established. Breast milk miRNAs (microRNAs) have been found to be differentially expressed in diverse tissues and biological processes during various molecular functions. Lactation is reported to assist mothers and their offspring to adapt to an ever-changing food supply. It has been observed that certain subtypes of miRNAs exist that are codified by non-human genomes but are still present in circulation. They have been termed as xeno-miRNA (XenomiRs). XenomiRs in humans have been found from various exogenous sources. Route of entry in human systems have been mainly dietary. The possibility of miRNAs taken up into mammalian circulation through diet, and thereby effecting gene expression, is a distinct possibility. This mechanism suggests an interesting possibility that dietary foods may modulate the immune strength of infants via highly specific post-transcriptional regulatory information present in mother's milk. This serves as a major breakthrough in understanding the fundamentals of nutrition and cross-organism communication. In this review, we elaborate and understand the complex crosstalk of XenomiRs present in mother's milk and their plausible role in modulating the infant immune system against infectious and inflammatory diseases.

Mapping Research in the Obesity, Adipose Tissue, and MicroRNA Field: A Bibliometric Analysis

Recent studies have investigated the control of adipose tissue expansion and inflammatory process by microRNAs (miRNAs). These two processes are of great interest because both are associated with obesity and metabolic syndrome. However, despite the great relevance of the role of miRNAs in obesity and adipose tissue, no qualitative and quantitative analysis on the subject has been performed. Thus, we aimed to examine global research activity and current trends with respect to the interaction between obesity, adipose tissue and miRNAs through a bibliometric analysis. This research was performed on the Scopus database for publications containing miRNA, obesity, and adipose tissue keyword combinations. In total, 898 articles were analyzed and the most frequently occurring keywords were selected and clustered into three well-defined groups. As a result, first group of keywords pointed to the research area on miRNAs expressed in obesity-associated diseases. The second group demonstrated the regulation of the adipogenesis process by miRNAs, while the third group highlighted brown adipose tissue and thermogenesis as one of the latest global research trends related to the theme. The studies selected in this paper describe the expression and performance of different miRNAs in obesity and comorbidities. Most studies have focused on identifying miRNAs and signaling pathways associated with obesity, type 2 diabetes mellitus, and cardiovascular disease. Thus, the miRNA profile for these diseases may be used as biomarkers and therapeutic targets in the prevention and treatment of obesity-associated diseases.

Interactions between immune response to fungal infection and microRNAs: The pioneer tuners

Due to their physiological and biological characteristics, numerous fungi are potentially emerging pathogens. Active dynamicity of fungal pathogens causes life-threatening infections annually impose high costs to the health systems. Although immune responses play crucial roles in controlling the fate of fungal infections, immunocompromised patients are at high risk with high mortality. Tuning the immune response against fungal infections might be an effective strategy for controlling and reducing the pathological damages. MicroRNAs (miRNAs) are known as the master regulators of immune response. These single-stranded tuners (18-23 bp non-coding RNAs) are endogenously expressed by all metazoan eukaryotes and have emerged as the master gene expression controllers of at least 30% human genes. In this review article, following the review of biology and physiology (biogenesis and mechanism of actions) of miRNAs and immune response against fungal infections, the interactions between them were scrutinised. In conclusion, miRNAs might be considered as one of the potential goals in immunotherapy for fungal infections. Undoubtedly, advanced studies in this field, further identifying of miRNA roles in governing the immune response, pave the way for inclusion of miRNA-related immunotherapeutic in the treatment of life-threatening fungal infections.

Circulating Plasma microRNAs are Altered with Amyloidosis in a Mouse Model of Alzheimer's Disease

Pathological changes underlying Alzheimer's disease (AD) begin decades before the classical symptoms of memory loss become evident. As microRNAs are released from neurons and enter the bloodstream, circulating microRNAs may be reflective of AD progression and are ideal candidates as biomarkers for early-stage disease detection. Here, we provide a novel, in-depth analysis of how plasma microRNAs alter with aging, the most prominent risk factor for AD, and with development of amyloid-β (Aβ) plaque deposition. We assessed the circulating microRNAs in APPswe/PSEN1dE9 transgenic mice and wild-type controls at 4, 8 and 15 m (n = 8-10) using custom designed Taqman arrays representing 185 neuropathology-related microRNAs. We performed a linear mixed-effects model to investigate the effects of age and genotype on plasma microRNAs expression. Following this analysis, we found 8 microRNAs were significantly affected by age alone in wild-type animals and 12 microRNAs altered in APPswe/PSEN1dE9 mice, either prior to Aβ plaque deposition (4 m) or during the development of AD-like pathogenesis (8 m or 15 m). Importantly, we found that differing sets of microRNAs were identified at each time point. Functional analysis of these data revealed that while common biological pathways, such as Inflammatory Response, were enriched throughout the disease process, Free Radical Scavenging, Immunological Disease, and Apoptosis Signaling were specifically enriched later in the disease process. Overall, this study reinforces that distinct biological processes underpin the early versus late stages of AD-like pathogenesis and highlights potential pre-symptomatic microRNAs biomarkers of neurodegeneration.

The Role of miRNAs in Immune Cell Development, Immune Cell Activation, and Tumor Immunity: With a Focus on Macrophages and Natural Killer Cells

The tumor microenvironment (TME) is the primary arena where tumor cells and the host immune system interact. Bidirectional communication between tumor cells and the associated stromal cell types within the TME influences disease initiation and progression, as well as tumor immunity. Macrophages and natural killer (NK) cells are crucial components of the stromal compartment and display either pro- or anti-tumor properties, depending on the expression of key regulators. MicroRNAs (miRNAs) are emerging as such regulators. They affect several immune cell functions closely related to tumor evasion of the immune system. This review discusses the role of miRNAs in the differentiation, maturation, and activation of immune cells as well as tumor immunity, focusing particularly on macrophages and NK cells.

A detailed image of rutin underlying intracellular signaling pathways in human SW480 colorectal cancer cells based on miRNAs-lncRNAs-mRNAs-TFs interactions

Natural dietary ingredients like flavonoids are important for body improvement against diseases. The flavonol rutin is widely found in fruits and vegetables and shows significant anticancer properties. However, the underlined signaling pathways have not been elucidated yet. In this study, the impacts of various doses of rutin (400-700 mM/ml) have been examined on human colon cancer SW480 cells metabolism, cell cycle, and apoptosis. The transcriptome was analyzed by bioinformatics tools and the interactions between rutin modulated microRNAs (miRNAs), long noncoding RNAs (lncRNAs), messenger RNAs (mRNAs), and transcription factors (TFs) were built, filtered and enriched. A dose of 600 mM of rutin significantly decreased cells metabolic activity, halved the population and arrested the cell cycle at the sub-G1 phase. The enrichment analysis of miRNAs-lncRNAs-mRNAs-TFs network showed that these effects were mediated through alteration of glucose, lipid, and protein metabolism, modulating endoplasmic reticulum stress responses, negative regulation of cell cycle process, and inducing the extrinsic and intrinsic apoptotic signaling pathways. Additionally, the key parent nodes of each annotation were illustrated. These findings create a detailed image of rutin underlying intracellular signaling pathways in CRC and also help us to better understand the role of dietary natural compounds in cancer treatment.

Interaction of transforming growth factor-β-Smads/microRNA-362-3p/CD82 mediated by M2 macrophages promotes the process of epithelial-mesenchymal transition in hepatocellular carcinoma cells

Abnormal tumor microenvironment and the epithelial‐mesenchymal transition (EMT) are important features of tumor metastasis. However, it remains unknown how signals can form complicated networks to regulate the sustainability of the EMT process. The aim of our study is to explore the possible interaction between tumor‐associated macrophages and tumor cells in the EMT process mediated by microRNA (miR)‐362‐3p. In this study, we found that by releasing TGF‐β, M2 macrophages mediate binding of Smad2/3 to miR‐362‐3p promoter, leading to overexpression of miR‐362‐3p. MicroRNA‐362‐3p maintains EMT by regulating CD82, one of the most important members of the family of tetraspanins. Our finding suggests that miR‐362‐3p can serve as a core factor mediating cross‐talk between the TGF‐β pathway in tumor‐associated macrophages and tetraspanins in tumor cells, and thus facilitates the EMT process.

PPAR-γ: Its ligand and its regulation by microRNAs

Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear receptor superfamily. PPARs are categorized into three subtypes, PPARα, β/δ, and γ, encoded by different genes, expressed in diverse tissues and participate in various biological functions and can be activated by their metabolic derivatives in the body or dietary fatty acids. The PPAR-γ also takes parts in the regulation of energy balance, lipoprotein metabolism, insulin sensitivity, oxidative stress, and inflammatory signaling. It has been implicated in the pathology of numerous diseases including obesity, diabetes, atherosclerosis, and cancers. Among various cellular and molecular targets that are able to regulate PPAR-γ and its underlying pathways, microRNAs (miRNAs) appeared as important regulators. Given that the deregulation of these molecules via targeting PPAR-γ could affect initiation and progression of various diseases, identification of miRNAs that affects PPAR-γ could contribute to the better understanding of roles of PPAR-γ in various biological and pathological conditions. Here, we have summarized the function and various ligands of PPAR-γ and have highlighted various miRNAs involved in the regulation of PPAR-γ.

Transgenic Exosomes for Thymus Regeneration

During senescence, Wnt4 expression is down-regulated (unlike their Frizzled receptors), while PPARgamma expression increases in the thymus. Together, these changes allow for thymic degeneration to occur, observed as adipose involution. However, when restored, Wnt4 can efficiently counteract PPARgamma and prevent thymic senescence from developing. The Wnt-pathway activator miR27b has also been reported to inhibit PPARgamma. Our goal was to evaluate the Wnt4 and miR27b levels of Wnt4-transgenic thymic epithelial cell (TEC)-derived exosomes, show their regenerative potential against age-related thymic degeneration, and visualize their binding and distribution both in vitro and in vivo. First, transgenic exosomes were harvested from Wnt4 over-expressing TECs and analyzed by transmission electron microscopy. This unveiled exosomes ranging from 50 to 100 nm in size. Exosomal Wnt4 protein content was assayed by ELISA, while miR27b levels were measured by TaqMan qPCR, both showing elevated levels in transgenic exosomes relative to controls. Of note, kit-purified TEI (total exosome isolate) outperformed UC (ultracentrifugation)-purified exosomes in these parameters. In addition, a significant portion of exosomal Wnt4 proved to be displayed on exosomal surfaces. For functional studies, steroid (Dexamethasone or DX)-induced TECs were used as cellular aging models in which DX-triggered cellular aging was efficiently prevented by transgenic exosomes. Finally, DiI lipid-stained exosomes were applied on the mouse thymus sections and also iv-injected into mice, for in vitro binding and in vivo tracking, respectively. We have observed distinct staining patterns using DiI lipid-stained transgenic exosomes on sections of young and aging murine thymus samples. Moreover, in vivo injected DiI lipid-stained transgenic exosomes showed detectable homing to the thymus. Of note, Wnt4-transgenic exosome homing outperformed control (Wnt5a-transgenic) exosome homing. In summary, our findings indicate that exosomal Wnt4 and miR27b can efficiently counteract thymic adipose involution. Although extrapolation of mouse results to the human setting needs caution, our results appoint transgenic TEC exosomes as promising tools of immune rejuvenation and contribute to the characterization of the immune-modulatory effects of extracellular vesicles in the context of regenerative medicine.

Exploration of exosomal microRNA expression profiles in pigeon 'Milk' during the lactation period

Background

Pigeon crop has the unique ability to produce a nutrient rich substance termed pigeon ‘milk’ (PM), which has functional resemblance with the mammalian milk. Previous researches have demonstrated that a large number of exosomes and exosomal miRNAs exist in mammalian milk, and many of them are associated with immunity, growth and development. However, to date, little is known about the exosomes and exosomal miRNAs in PM.

Results

In this study, we isolated the exosomes from PM and used small RNA sequencing to investigate the distribution and expression profiles of exosomal miRNAs. A total of 301 mature miRNAs including 248 conserved and 53 novel miRNAs were identified in five lactation stages i.e. 1d, 5d, 10d, 15d, and 20d. From these, four top 10 conserved miRNAs (cli-miR-21-5p, cli-miR-148a-3p, cli-miR-10a-5p and cli-miR-26a-5p) were co-expressed in all five stages. We speculate that these miRNAs may have important role in the biosynthesis and metabolism of PM. Moreover, similar to the mammalian milk, a significant proportion of immune and growth-related miRNAs were also present and enriched in PM exosomes. Furthermore, we also identified 41 orthologous miRNAs group (giving rise to 81 mature miRNA) commonly shared with PM, human, bovine and porcine breast milk. Additionally, functional enrichment analysis revealed the role of exosomal miRNAs in organ development and in growth-related pathways including the MAPK, Wnt and insulin pathways.

Conclusions

To sum-up, this comprehensive analysis will contribute to a better understanding of the underlying functions and regulatory mechanisms of PM in squabs.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5201-0) contains supplementary material, which is available to authorized users.