miR-543 and miR-590-3p regulate human mesenchymal stem cell aging via direct targeting of AIMP3/p18

Consequences of Aging on Bone

With the aging of the global population, the incidence of musculoskeletal diseases has been increasing, seriously affecting people's health. As people age, the microenvironment within skeleton favors bone resorption and inhibits bone formation, accompanied by bone marrow fat accumulation and multiple cellular senescence. Specifically, skeletal stem/stromal cells (SSCs) during aging tend to undergo adipogenesis rather than osteogenesis. Meanwhile, osteoblasts, as well as osteocytes, showed increased apoptosis, decreased quantity, and multiple functional limitations including impaired mechanical sensing, intercellular modulation, and exosome secretion. Also, the bone resorption function of macrophage-lineage cells (including osteoclasts and preosteoclasts) was significantly enhanced, as well as impaired vascularization and innervation. In this study, we systematically reviewed the effect of aging on bone and the within microenvironment (including skeletal cells as well as their intracellular structure variations, vascular structures, innervation, marrow fat distribution, and lymphatic system) caused by aging, and mechanisms of osteoimmune regulation of the bone environment in the aging state, and the causal relationship with multiple musculoskeletal diseases in addition with their potential therapeutic strategy.

miRNA and lncRNA Expression Networks Modulate Cell Cycle and DNA Repair Inhibition in Senescent Prostate Cells

Cellular senescence is a state of permanent growth arrest that arises once cells reach the limit of their proliferative capacity. It creates an inflammatory microenvironment favouring the initiation and progression of various age-related diseases, including prostate cancer. Non-coding RNAs (ncRNAs) have emerged as important regulators of cellular gene expression. Nonetheless, very little is known about the interplay of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) and how deregulation of ncRNA networks promotes cellular senescence. To investigate this, human prostate epithelial cells were cultured through different passages until senescent, and their RNA was extracted and sequenced using RNA sequencing (RNAseq) and microRNA sequencing (miRNA-seq) miRNAseq. Differential expression (DE) gene analysis was performed to compare senescent and proliferating cells with Limma, miRNA-target interactions with multiMiR, lncRNA-target interactions using TCGA data and network evaluation with miRmapper. We found that miR-335-3p, miR-543 and the lncRNAs H19 and SMIM10L2A all play central roles in the regulation of cell cycle and DNA repair processes. Expression of most genes belonging to these pathways were down-regulated by senescence. Using the concept of network centrality, we determined the top 10 miRNAs and lncRNAs, with miR-335-3p and H19 identified as the biggest hubs for miRNAs and lncRNA respectively. These ncRNAs regulate key genes belonging to pathways involved in cell senescence and prostate cancer demonstrating their central role in these processes and opening the possibility for their use as biomarkers or therapeutic targets to mitigate against prostate ageing and carcinogenesis.

Immunomodulating Profile of Dental Mesenchymal Stromal Cells: A Comprehensive Overview

Dental mesenchymal stromal cells (MSCs) are multipotent cells present in dental tissues, characterized by plastic adherence in culture and specific surface markers (CD105, CD73, CD90, STRO-1, CD106, and CD146), common to all other MSC subtypes. Dental pulp, periodontal ligament, apical papilla, human exfoliated deciduous teeth, alveolar bone, dental follicle, tooth germ, and gingiva are all different sources for isolation and expansion of MSCs. Dental MSCs have regenerative and immunomodulatory properties; they are scarcely immunogenic but actively modulate T cell reactivity. in vitro studies and animal models of autoimmune diseases have provided evidence for the suppressive effects of dental MSCs on peripheral blood mononuclear cell proliferation, clearance of apoptotic cells, and promotion of a shift in the Treg/Th17 cell ratio. Appropriately stimulated MSCs produce anti-inflammatory mediators, such as transforming growth factor-β (TGF-β), prostaglandin E2, and interleukin (IL)-10. A particular mechanism through which MSCs exert their immunomodulatory action is via the production of extracellular vesicles containing such anti-inflammatory mediators. Recent studies demonstrated MSC-mediated inhibitory effects both on monocytes and activated macrophages, promoting their polarization to an anti-inflammatory M2-phenotype. A growing number of trials focusing on MSCs to treat autoimmune and inflammatory conditions are ongoing, but very few use dental tissue as a cellular source. Recent results suggest that dental MSCs are a promising therapeutic tool for immune-mediated disorders. However, the exact mechanisms responsible for dental MSC-mediated immunosuppression remain to be clarified, and impairment of dental MSCs immunosuppressive function in inflammatory conditions and aging must be assessed before considering autologous MSCs or their secreted vesicles for therapeutic purposes.

The Mechanism of Stem Cell Aging

Stem cells have self-renewal ability and multi-directional differentiation potential. They have tissue repair capabilities and are essential for maintaining the tissue homeostasis. The depletion of stem cells is closely related to the occurrence of body aging and aging-related diseases. Therefore, revealing the molecular mechanisms of stem cell aging will set new directions for the therapeutic application of stem cells, the study of aging mechanisms, and the prevention and treatment of aging-related diseases. This review comprehensively describes the molecular mechanisms related to stem cell aging and provides the basis for further investigations aimed at developing new anti-stem cell aging strategies and promoting the clinical application of stem cells.

Role of miRNA and lncRNAs in organ fibrosis and aging

Fibrosis is the endpoint of pathological remodeling. This process contributes to the pathogenesis of several chronic disorders and aging-associated organ damage. Different molecular cascades contribute to this process. TGF-β, WNT, and YAP/TAZ signaling pathways have prominent roles in this process. A number of long non-coding RNAs and microRNAs have been found to regulate organ fibrosis through modulation of the activity of related signaling pathways. miR-144-3p, miR-451, miR-200b, and miR-328 are among microRNAs that participate in the pathology of cardiac fibrosis. Meanwhile, miR-34a, miR-17-5p, miR-122, miR-146a, and miR-350 contribute to liver fibrosis in different situations. PVT1, MALAT1, GAS5, NRON, PFL, MIAT, HULC, ANRIL, and H19 are among long non-coding RNAs that participate in organ fibrosis. We review the impact of long non-coding RNAs and microRNAs in organ fibrosis and aging-related pathologies.

AIMP3 induces laminopathy and senescence of vascular smooth muscle cells by reducing lamin A expression and leads to vascular aging in vivo

Aminoacyl-tRNA synthetase-interacting multifunctional protein 3 (AIMP3), a tumor suppressor, mediates a progeroid phenotype in mice by downregulating lamin A. We investigated whether AIMP3 induces laminopathy and senescence of human aortic smooth muscle cells (HASMCs) and is associated with vascular aging in mice and humans in line with decreased lamin A expression. Cellular senescence was evaluated after transfecting HASMCs with AIMP3. Molecular analyses of genes encoding AIMP3, lamin A, chemokine (C-C motif) ligand 2 (CCL2), and C-C chemokine receptor type 2 (CCR2) and histological comparisons of aortas were performed with mice at various ages (7 weeks, 5 months, 12 months, 24 months, and 32 months), AIMP3-transgenic mice, and human femoral arteries of cadavers. AIMP3-transfected HASMCs exhibited increased AIMP3 and senescence marker p16 protein expression and decreased lamin A protein expression in accordance with their disrupted nuclear morphology in histological analyses. AIMP3-transgenic mice displayed increased AIMP3 protein expression and decreased lamin A protein expression in aortas together with typical aging pathologies. Similar changes were observed in wild-type aging (24-month-old) mice but not in wild-type young (7-week-old) mice. In humans, AIMP3 and lamin A protein expression was higher and lower, respectively, in femoral arteries of elderly individuals than in those of their younger counterparts. This study found that AIMP3 overexpression in vitro decreased lamin A expression and induced nuclear laminopathy and cellular senescence. Similar findings were made in the vasculature of aging mice and elderly humans.

miR-543 in human mesenchymal stem cell-derived exosomes promotes cardiac microvascular endothelial cell angiogenesis after myocardial infarction through COL4A1

To explore the impact and mechanism of human mesenchymal stem cells (hMSCs) on the angiogenesis of cardiac microvascular endothelial cells (CMECs) after ischemia insult. Exosomes derived from hMSCs (hMSCs-Exo) were identified by Western blotting and labeled by PHK-67. CMECs were isolated from rat myocardial tissues. After hypoxic treatment, CMECs were cultured with hMSCs and exosome inhibitor (GW4869) or transfected with si-COL4A1 + miR-543 inhibitor. CMEC proliferation, migration, invasion, and angiogenesis were examined. Target genes of miR-543 were predicted and then were identified by dual luciferase assay. Myocardial infarction (MI) rat model established by suture occlusion was intravenously injected with hMSCs-Exo. Fluorescence microscope was applied to visualize exosomes in myocardial tissues. Infarction volume and pathologies of myocardial tissues were observed. Ki-67 and miR-543 expressions were detected. The isolated hMSC-Exo expressed TSG101, HSP70, and CD63. Hypoxia-treated CMECs cultured with hMSCs exhibited high proliferation, migration, invasion, and angiogenesis ability, while incubation with exosome inhibitor GW4969 offset the promoting effects of hMSCs on the proliferation, migration, invasion, and angiogenesis of CMECs. hMSCs transfected with miR-543 inhibitor brought CMECs weak viability and angiogenesis ability. CMECs transfected with si-COL4A1 and miR-543 inhibitor showed low proliferation, migration, invasion, and angiogenesis compared to those transfected with si-COL4A1 alone. hMSCs-Exo entered the myocardial tissues of MI rats. Injection of hMSCs-Exo in MI rats diminished infarction size, attenuated MI-induced injuries, and increased Ki-67 expression. hMSCs-Exo facilitates the proliferation, migration, invasion, and angiogenesis of CMECs through transferring miR-543 and downregulating COL4A1 expression.

Roles of tRNA metabolism in aging and lifespan

Transfer RNAs (tRNAs) mainly function as adapter molecules that decode messenger RNAs (mRNAs) during protein translation by delivering amino acids to the ribosome. Traditionally, tRNAs are considered as housekeepers without additional functions. Nevertheless, it has become apparent from biological research that tRNAs are involved in various physiological and pathological processes. Aging is a form of gradual decline in physiological function that ultimately leads to increased vulnerability to multiple chronic diseases and death. Interestingly, tRNA metabolism is closely associated with aging and lifespan. In this review, we summarize the emerging roles of tRNA-associated metabolism, such as tRNA transcription, tRNA molecules, tRNA modifications, tRNA aminoacylation, and tRNA derivatives, in aging and lifespan, aiming to provide new ideas for developing therapeutics and ultimately extending lifespan in humans.

Non-Coding RNAs Steering the Senescence-Related Progress, Properties, and Application of Mesenchymal Stem Cells

The thirst to postpone and even reverse aging progress has never been quenched after all these decades. Unequivocally, mesenchymal stem cells (MSCs), with extraordinary abilities such as self-renewal and multi-directional differentiation, deserve the limelight in this topic. Though having several affable clinical traits, MSCs going through senescence would, on one hand, contribute to age-related diseases and, on the other hand, lead to compromised or even counterproductive therapeutical outcomes. Notably, increasing evidence suggests that non-coding RNAs (ncRNAs) could invigorate various regulatory processes. With even a slight dip or an uptick of expression, ncRNAs would make a dent in or even overturn cellular fate. Thereby, a systematic illustration of ncRNAs identified so far to steer MSCs during senescence is axiomatically an urgent need. In this review, we introduce the general properties and mechanisms of senescence and its relationship with MSCs and illustrate the ncRNAs playing a role in the cellular senescence of MSCs. It is then followed by the elucidation of ncRNAs embodied in extracellular vesicles connecting senescent MSCs with other cells and diversified processes in and beyond the skeletal system. Last, we provide a glimpse into the clinical methodologies of ncRNA-based therapies in MSC-related fields. Hopefully, the intricate relationship between senescence and MSCs will be revealed one day and our work could be a crucial stepping-stone toward that future.

LncRNA NEAT1 promotes cell proliferation, migration, and invasion via the miR-186-5p/PTP4A1 axis in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a highly aggressive and malignant tumor. In this study, the effect and molecular mechanism of nuclear enriched abundant transcript 1 (NEAT1) in CCA were elucidated. The expressions of NEAT1, microRNA-186-5p (miR-186-5p), and PTP4A1 were measured by quantitative real-time PCR. The protein levels were measured by Western blotting. Kaplan-Meier analysis was performed to create survival curves. The interactions between NEAT1, miR-186-5p, and PTP4A1 were assessed through the dual luciferase reporter assay. Additionally, the cell proliferation, apoptosis, migration, and invasion were measured by colony formation, flow cytometry, the Transwell assay, and the wound healing assay, respectively. NEAT1 and PTP4A1 were significantly upregulated in CCA tissues and cells, but miR-186-5p was downregulated. NEAT1 expression was negatively correlated with the survival of CCA patients and has remarkable correlation with serum CA199 levels and lymph node metastasis. Besides, NEAT1 could act as a molecular sponge for miR-186-5p to upregulate PTP4A1 expression. More importantly, the knockdown of NEAT1 or overexpression of miR-186-5p inhibited the proliferation, migration and invasion of CCA cells, and the inhibition of miR-186-5p reversed the effects of the knockdown of NEAT1. In addition, NEAT1 could also activate the PI3K/AKT signaling pathway and regulate the epithelial-mesenchymal transition (EMT) through the miR-186-5p/PTP4A1 axis. In conclusion, NEAT1 was involved in cell proliferation, migration and invasion in CCA, and the NEAT1/miR-186-5p/PTP4A1/PI3K/AKT axis indicated novel regulatory mechanisms and therapeutics for the treatment of CCA.

MicroRNAs are critical regulators of senescence and aging in mesenchymal stem cells

MicroRNAs (miRNAs) have recently come under scrutiny for their role in various age-related diseases. Similarly, cellular senescence has been linked to disease and aging. MicroRNAs and senescence likely play an intertwined role in driving these pathologic states. In this review, we present the connection between these two drivers of age-related disease concerning mesenchymal stem cells (MSCs). First, we summarize key miRNAs that are differentially expressed in MSCs and other musculoskeletal lineage cells during senescence and aging. Additionally, we also reviewed miRNAs that are regulated via traditional senescence-associated secretory phenotype (SASP) cytokines in MSC. Lastly, we summarize miRNAs that have been found to target components of the cell cycle arrest pathways inherently activated in senescence. This review attempts to highlight potential miRNA targets for regenerative medicine applications in age-related musculoskeletal disease.

Hsa-MiR-590-3p Promotes the Malignancy Progression of Pancreatic Ductal Carcinoma by Inhibiting the Expression of p27 and PPP2R2A via G1/S Cell Cycle Pathway

Objective

To investigate the effect of miR-590-3p on the malignant biological behavior of pancreatic cancer, and to explore the target genes and pathways directly affected by miR-590-3p, to provide new therapeutic ideas and targets for the study of the diagnosis and treatment of pancreatic cancer.

Methods

We used qRT-PCR to measure miR-590-3p expression quantities. We used cell cycle, CCK-8, clonal formation to verify the change of proliferation capacity of PC cells. We used transwell assay to detect the migration and invasion of PC cells. We used the bioinformatics tool TargetScan (http://www.targetscan.org) to identify the possible target genes of miR-590-3p. Immunohistochemistry revealed the clinicopathological significance of PPP2R2A, p27 and miR-590-3p in the expression of pancreatic cancer. Western blot was used to detect the expression changes of PPP2R2A, p27 and G1/S cell cycle pathway-related proteins CDK2, cyclinE2 and p21 after transfection of mimics and inhibitors of miR-590-3p.

Results

According to our study, hsa-miR-590-3p expression was significantly higher in PC tissues than that in paired normal pancreas, which was associated with PC tumor size (P=0.042) and preoperative CA19-9 level (P=0.046) of PC patients. Its overexpression promoted PC cell proliferation, invasion and migration following with the p27 and PPP2R2A protein downregulation in Capan-2, PANC-1 and BxPC-3 cells, and vice versa. Bioinformatics analysis and dual-luciferase reporter assay further confirmed that p27 and PPP2R2A were direct target genes of miR-590-3p. The negative relationship of miR-590-3p with p27 and PPP2R2A was also observed in PC tissues.

Conclusion

MiR-590-3p promotes the proliferation, migration and invasion of pancreatic cancer cells. MiR-590-3p directly downregulated p27 and PPP2R2A and via the G1/S cell cycle pathway to promote the development of pancreatic cancer.

Long non-coding RNA maternally expressed gene 3 inhibits osteogenic differentiation of human dental pulp stem cells via microRNA-543/smad ubiquitin regulatory factor 1/runt-related transcription factor 2 axis

OBJECTIVE

The aim of the present study was to investigate the biological roles and underlying mechanism of the long non-coding RNA maternally expressed gene 3 (MEG3) on osteogenic differentiation of human dental pulp stem cells (hDPSCs).

METHODS

The expression levels of MEG3, microRNA-543 (miR-543), osterix, osteopontin, osteocalcin and runt-related transcription factor 2 (RUNX2) were measured by quantitative real-time PCR (qRT-PCR). Alkaline phosphatase (ALP) activity assay and alizarin red S staining (ARS) were used to measure the impacts exerted by MEG3, miR-543 on osteogenic differentiation. Cell proliferation was measured by MTT assay. In addition, the targeted relationships between miR-543, MEG3, and Smad ubiquitin regulatory factor 1 (SMURF1) were assessed through dual luciferase reporter assay.

RESULTS

During osteogenic induction, the expression of MEG3 was gradually reduced, whereas the expression of miR-543, osterix, osteopontin, osteocalcin and RUNX2 were gradually increased. Functional analysis implied that MEG3 overexpression or miR-543 inhibition reduced the cell proliferation, ALP activity, ARS levels, and decreased the expression of osteoblast-related proteins. Moreover, MEG3 promoted SMURF1 expression by directly targeting miR-543 as a competing endogenous RNA. Furthermore, overexpression of miR-543 or silencing SMURF1 could reverse the inhibitory effects of MEG3 on the osteogenic differentiation of hDPSCs.

CONCLUSIONS

In conclusion, our study revealed that overexpression of MEG3 inhibited hDPSCs osteogenic differentiation via miR-543/SMURF1/RUNX2 regulatory network, which may contribute to the functional regulation and clinical applications of hDPSCs.

Senescent mesenchymal stem/stromal cells and restoring their cellular functions

Mesenchymal stem/stromal cells (MSCs) have various properties that make them promising candidates for stem cell-based therapies in clinical settings. These include self-renewal, multilineage differentiation, and immunoregulation. However, recent studies have confirmed that aging is a vital factor that limits their function and therapeutic properties as standardized clinical products. Understanding the features of senescence and exploration of cell rejuvenation methods are necessary to develop effective strategies that can overcome the shortage and instability of MSCs. This review will summarize the current knowledge on characteristics and functional changes of aged MSCs. Additionally, it will highlight cell rejuvenation strategies such as molecular regulation, non-coding RNA modifications, and microenvironment controls that may enhance the therapeutic potential of MSCs in clinical settings.

Epigenetic Regulation in Mesenchymal Stem Cell Aging and Differentiation and Osteoporosis

Mesenchymal stem cells (MSCs) are a reliable source for cell-based regenerative medicine owing to their multipotency and biological functions. However, aging-induced systemic homeostasis disorders in vivo and cell culture passaging in vitro induce a functional decline of MSCs, switching MSCs to a senescent status with impaired self-renewal capacity and biased differentiation tendency. MSC functional decline accounts for the pathogenesis of many diseases and, more importantly, limits the large-scale applications of MSCs in regenerative medicine. Growing evidence implies that epigenetic mechanisms are a critical regulator of the differentiation programs for cell fate and are subject to changes during aging. Thus, we here review epigenetic dysregulations that contribute to MSC aging and osteoporosis. Comprehending detailed epigenetic mechanisms could provide us with a novel horizon for dissecting MSC-related pathogenesis and further optimizing MSC-mediated regenerative therapies.

Knockdown of long non-coding RNA PVT1 induces apoptosis of fibroblast-like synoviocytes through modulating miR-543-dependent SCUBE2 in rheumatoid arthritis

Background

Rheumatoid arthritis (RA), a kind of autoimmune disorder, is featured by many physical symptoms and proliferation of fibroblast-like synoviocytes (FLSs). The relevance of long non-coding RNAs (lncRNAs) in the progression of RA has been probed. Hence, the goal of this report was to investigate the action of plasmacytoma variant translocation 1 (PVT1), a lncRNA, in FLSs and the basic mechanism.

Methods

Initially, RA rats were developed to evaluate the expression of PVT1, microRNA-543 (miR-543), and signal peptide-CUB-EGF-like containing protein 2 (SCUBE2) in synovial tissues. Enhancement or loss of PVT1 or miR-543 was achieved to explore their effects on proliferation, cell cycle, and apoptosis of FLSs. The interaction between PVT1 and miR-543 and between miR-543 and its putative target SCUBE2 was examined to elucidate the correlations. Finally, the protein expression of proliferation- and apoptosis-associated genes were assessed by western blot assays.

Results

PVT1 was overexpressed in synovial tissues from RA patients through microarray expression profiles. The PVT1 and SCUBE2 expression was boosted, and miR-543 was reduced in synovial tissues of rats with RA. PVT1 specifically bound to miR-543, and miR-543 negatively regulated SCUBE2 expression. Overexpression of PVT1 or silencing of miR-543 enhanced SCUBE2 expression, thereby promoting proliferation and interleukin-1β (IL-1β) secretion, while inhibiting apoptosis rate of FLSs. Conversely, si-SCUBE2 reversed the role of miR-543 inhibitor.

Conclusion

The key findings support that PVT1 knockdown has the potency to hinder RA progression by inhibiting SCUBE2 expression to sponge miR-543.

miR-155-5p inhibition rejuvenates aged mesenchymal stem cells and enhances cardioprotection following infarction

Aging impairs the functions of human mesenchymal stem cells (MSCs), thereby severely reducing their beneficial effects on myocardial infarction (MI). MicroRNAs (miRNAs) play crucial roles in regulating the senescence of MSCs; however, the underlying mechanisms remain unclear. Here, we investigated the significance of miR‐155‐5p in regulating MSC senescence and whether inhibition of miR‐155‐5p could rejuvenate aged MSCs (AMSCs) to enhance their therapeutic efficacy for MI. Young MSCs (YMSCs) and AMSCs were isolated from young and aged donors, respectively. The cellular senescence of MSCs was evaluated by senescence‐associated β‐galactosidase (SA‐β‐gal) staining. Compared with YMSCs, AMSCs exhibited increased cellular senescence as evidenced by increased SA‐β‐gal activity and decreased proliferative capacity and paracrine effects. The expression of miR‐155‐5p was much higher in both serum and MSCs from aged donors than young donors. Upregulation of miR‐155‐5p in YMSCs led to increased cellular senescence, whereas downregulation of miR‐155‐5p decreased AMSC senescence. Mechanistically, miR‐155‐5p inhibited mitochondrial fission and increased mitochondrial fusion in MSCs via the AMPK signaling pathway, thereby resulting in cellular senescence by repressing the expression of Cab39. These effects were partially reversed by treatment with AMPK activator or mitofusin2‐specific siRNA (Mfn2‐siRNA). By enhancing angiogenesis and promoting cell survival, transplantation of anti‐miR‐155‐5p‐AMSCs led to improved cardiac function in an aged mouse model of MI compared with transplantation of AMSCs. In summary, our study shows that miR‐155‐5p mediates MSC senescence by regulating the Cab39/AMPK signaling pathway and miR‐155‐5p is a novel target to rejuvenate AMSCs and enhance their cardioprotective effects.

Human Tonsil-Derived Mesenchymal Stromal Cells Maintain Proliferating and ROS-Regulatory Properties via Stanniocalcin-1

Mesenchymal stromal cells (MSCs) from various sources exhibit different potential for stemness and therapeutic abilities. Recently, we reported a unique MSCs from human palatine tonsil (TMSCs) and their superior proliferation capacity compared to MSCs from other sources. However, unique characteristics of each MSC are not yet precisely elucidated. We investigated the role of stanniocalcin-1 (STC1), an anti-oxidative hormone, in the functions of TMSCs. We found that STC1 was highly expressed in TMSC compared with MSCs from bone marrow or adipose tissue. The proliferation, senescence and differentiation of TMSCs were assessed after the inhibition of STC1 expression. STC1 inhibition resulted in a significant decrease in the proliferation of TMSCs and did not affect the differentiation potential. To reveal the anti-oxidative ability of STC1 in TMSCs themselves or against other cell types, the generation of mitochondrial reactive oxygen species (ROS) in TMSC or ROS-mediated production of interleukin (IL)-1β from macrophage-like cells were detected. Interestingly, the basal level of ROS generation in TMSCs was significantly elevated after STC1 inhibition. Moreover, down-regulation of STC1 impaired the inhibitory effect of TMSCs on IL-1β production in macrophages. Taken together, these findings indicate that STC1 is highly expressed in TMSCs and plays a critical role in proliferating and ROS-regulatory abilities.

Emerging role of stem cell-derived extracellular microRNAs in age-associated human diseases and in different therapies of longevity

Organismal aging involves the progressive decline in organ function and increased susceptibility to age-associated diseases. This has been associated with the aging of stem cell populations within the body that decreases the capacity of stem cells to self-renew, differentiate, and regenerate damaged tissues and organs. This review aims to explore how aging is associated with the dysregulation of stem cell-derived extracellular vesicles (SCEVs) and their corresponding miRNA cargo (SCEV-miRNAs), which are short non-coding RNAs involved in post-transcriptional regulation of target genes. Recent evidence has suggested that in aging stem cells, SCEV-miRNAs may play a vital role regulating various processes that contribute to aging: cellular senescence, stem cell exhaustion, telomere length, and circadian rhythm. Hence, further clarifying the age-dependent molecular mechanisms through which SCEV-miRNAs exert their downstream effects may inform a greater understanding of the biology of aging, elucidate their role in stem cell function, and identify important targets for future regenerative therapies. Additionally, current studies evaluating therapeutic role of SCEVs and SCEV-miRNAs in treating several age-associated diseases are also discussed.

Tensin-3 Regulates Integrin-Mediated Proliferation and Differentiation of Tonsil-Derived Mesenchymal Stem Cells

Human palatine tonsils are potential tissue source of multipotent mesenchymal stem cells (MSCs). The proliferation rate of palatine tonsil-derived MSCs (TMSCs) is far higher than that of bone marrow-derived MSCs (BMSCs) or adipose tissue-derived MSCs (ADSCs). In our previous study, we had found through DNA microarray analysis that tensin-3 (TNS3), a type of focal adhesion protein, was more highly expressed in TMSCs than in both BMSCs and ADSCs. Here, the role of TNS3 in TMSCs and its relationship with integrin were investigated. TNS3 expression was significantly elevated in TMSCs than in other cell types. Cell growth curves revealed a significant decrease in the proliferation and migration of TMSCs treated with siRNA for TNS3 (siTNS3). siTNS3 treatment upregulated p16 and p21 levels and downregulated SOX2 expression and focal adhesion kinase, protein kinase B, and c-Jun N-terminal kinase phosphorylation. siTNS3 transfection significantly reduced adipogenic differentiation of TMSCs and slightly decreased osteogenic and chondrogenic differentiation. Furthermore, TNS3 inhibition reduced active integrin beta-1 (ITGβ1) expression, while total ITGβ1 expression was not affected. Inhibition of ITGβ1 expression in TMSCs by siRNA showed similar results observed in TNS3 inhibition. Thus, TNS3 may play an important role in TMSC proliferation and differentiation by regulating active ITGβ1 expression.

Roles of differential expression of miR-543-5p in GH regulation in rat anterior pituitary cells and GH3 cells

Growth hormone (GH) is an important hormone released by the pituitary gland that plays a key role in the growth and development of organisms. In our study, TargetScan analysis and the dual luciferase reporter assays were used to predict and screen for miRNAs that might act on the rat Gh1 gene, and we identified miR-543-5p. Then, the GH3 cell line and the primary rat pituitary cells were transfected with miRNA mimic, inhibitor, and siRNA. We detected the Gh1 gene expression and the GH secretion by real-time PCR and ELISAs, respectively, to verify the regulatory effect of miR-543-5p on GH secretion. The results showed that miR-543-5p can inhibit Gh1 mRNA expression and reduce GH secretion. MiR-543-5p inhibitor upregulated Gh1 mRNA expression and increased GH secretion compared with the negative control. In summary, miR-543-5p downregulates Gh1 expression, resulting in a decrease in GH synthesis and secretion, which demonstrates the important role of miRNAs in regulating GH and animal growth and development.

Screening of underlying genetic biomarkers for ankylosing spondylitis

Genetic biomarkers for the diagnosis of ankylosing spondylitis (AS) remain unreported except for human leukocyte antigen B27 (HLA-B27). Therefore, the aim of the present study was to screen the differentially expressed genes (DEGs), and those that also possess differential single nucleotide polymorphism (SNP) loci in the whole blood of AS patients compared with healthy controls by integrating two mRNA expression profiles (GSE73754 and GSE25101) and SNP microarray data (GSE39428) collected from the Gene Expression Omnibus (GEO). Using the t-test, 1,056 and 1,073 DEGs were identified in the GSE73754 and GSE25101 datasets, respectively. Among them, 234 DEGs were found to be shared in both datasets, which were subsequently overlapped with 122 differential SNPs of genes in the GSE39428 dataset, resulting in identification of two common genes [eukaryotic translation elongation factor 1 epsilon 1 (EEF1E1) and serpin family A member 1 (SERPINA1)]. Their expression levels were significantly upregulated and the average expression log R ratios of SNP sites in these genes were significantly higher in AS patients than those in controls. Function enrichment analysis revealed that EEF1E1 was involved in AS by influencing the aminoacyl-tRNA biosynthesis, while SERPINA1 may be associated with AS by participating in platelet degranulation. However, only the genotype and allele frequencies of SNPs (rs7763907 and rs7751386) in EEF1E1 between AS and controls were significantly different between AS and the controls, but not SERPINA1. These findings suggest that EEF1E1 may be an underlying genetic biomarker for the diagnosis of AS.

HIF1α-mediated AIMP3 suppression delays stem cell aging via the induction of autophagy

Senescence in stem cells, which occurs as a consequence of chronic responses to the environment, defines the capacity of stem cells for proliferation and differentiation as well as their potential for tissue regeneration and homeostasis maintenance. Although stem cells reside under low oxygen pressure and the availability of oxygen is known to be a crucial determinant in their fate, the key modulators in stem cell aging and the underlying mechanism have yet to be unraveled. Human placenta‐derived mesenchymal stem cells (hpMSCs) were cultured under hypoxia (3% O₂) or normoxia (21% O₂) to investigate the key factors that regulate stem cell senescence under hypoxic conditions. RNA sequencing results suggested that the expression of aminoacyl‐tRNA synthetase‐interacting multifunctional protein 3 (AIMP3, EEF1E1), an aging inducer, in the hpMSCs was dramatically repressed under hypoxia with concurrent suppression of the aging marker p16^INK4a. The hpMSCs that overexpressed AIMP3 under hypoxic conditions displayed significantly decreased proliferation and fewer stem cell characteristics, whereas the downregulation of AIMP3 ameliorated the age‐related senescence of MSCs. Consistent with the results of the hpMSCs, MSCs isolated from the adipose tissue of AIMP3‐overexpressing mice exhibited decreased stem cell functions. Interestingly, AIMP3‐induced senescence is negatively regulated by hypoxia‐inducible factor 1α (HIF1α) and positively regulated by Notch3. Furthermore, we showed that AIMP3 enhanced mitochondrial respiration and suppressed autophagic activity, indicating that the AIMP3‐associated modulation of metabolism and autophagy is a key mechanism in the senescence of stem cells and further suggesting a novel target for interventions against aging.

Alkylating anticancer agents and their relations to microRNAs

Alkylating agents represent an important class of anticancer drugs. The occurrence and emergence of tumor resistance to the treatment with alkylating agents denotes a severe problem in the clinics. A detailed understanding of the mechanisms of activity of alkylating drugs is essential in order to overcome drug resistance. In particular, the role of non-coding microRNAs concerning alkylating drug activity and resistance in various cancers is highlighted in this review. Both synthetic and natural alkylating agents, which are approved for cancer therapy, are discussed concerning their interplay with microRNAs.

The Winding Road of Cardiac Regeneration-Stem Cell Omics in the Spotlight

Despite significant progress in treating ischemic cardiac disease and succeeding heart failure, there is still an unmet need to develop effective therapeutic strategies given the persistent high-mortality rate. Advances in stem cell biology hold great promise for regenerative medicine, particularly for cardiac regeneration. Various cell types have been used both in preclinical and clinical studies to repair the injured heart, either directly or indirectly. Transplanted cells may act in an autocrine and/or paracrine manner to improve the myocyte survival and migration of remote and/or resident stem cells to the site of injury. Still, the molecular mechanisms regulating cardiac protection and repair are poorly understood. Stem cell fate is directed by multifaceted interactions between genetic, epigenetic, transcriptional, and post-transcriptional mechanisms. Decoding stem cells’ “panomic” data would provide a comprehensive picture of the underlying mechanisms, resulting in patient-tailored therapy. This review offers a critical analysis of omics data in relation to stem cell survival and differentiation. Additionally, the emerging role of stem cell-derived exosomes as “cell-free” therapy is debated. Last but not least, we discuss the challenges to retrieve and analyze the huge amount of publicly available omics data.

MiR-1292 Targets FZD4 to Regulate Senescence and Osteogenic Differentiation of Stem Cells in TE/SJ/Mesenchymal Tissue System via the Wnt/β-catenin Pathway

With the expansion of the elderly population, age-related osteoporosis and the resulting bone loss have become a significant health and socioeconomic issue. In Triple Energizer (TE)/San Jiao (SJ)/mesenchymal tissue system, mesenchymal stem cell (MSC) senescence, and impaired osteogenesis are thought to contribute to age-related diseases such as osteoporosis. Therefore, comprehending the molecular mechanisms underlying MSC senescence and osteogenesis is essential to improve the treatment of bone metabolic diseases. With the increasing role of miRNAs in MSC aging and osteogenic differentiation, we need to understand further how miRNAs participate in relevant mechanisms. In this study, we observed that the expression of miR-1292 was augmented during cellular senescence and lessened with osteogenesis in human adipose-derived mesenchymal stem cells (hADSCs). miR-1292 expression was positively correlated with senescence markers and negatively associated with bone formation markers in clinical bone samples. Overexpression of miR-1292 notably accelerated hADSC senescence and restrained osteogenesis, whereas its knockdown decreased senescence and enhanced osteogenic differentiation. Furthermore, miR-1292 upregulation inhibited ectopic bone formation in vivo. Mechanistically, FZD4 was identified as a potential target of miR-1292. Downregulation of FZD4 phenocopied the effect of miR-1292 overexpression on hADSC senescence and osteogenic differentiation. Moreover, the impact of miR-1292 suppression on senescence and osteogenesis were reversed by the FZD4 knockdown. Pathway analysis revealed that miR-1292 regulates hADSC senescence and osteogenesis through the Wnt/β-catenin signaling pathway. Thus, TE/SJ/mesenchymal tissue system is the largest organ composed of various functional cells derived from mesoderm, responsible for maintaining homeostasis and regulating cell senescence. miR-1292 might serve as a novel therapeutic target for the prevention and treatment of osteoporosis or other diseases related to bone metabolism and aging.

The Emerging Roles of microRNAs in Stem Cell Aging

Aging is the continuous loss of tissue and organ function over time. MicroRNAs (miRNAs) are thought to play a vital role in this process. miRNAs are endogenous small noncoding RNAs that control the expression of target mRNA. They are involved in many biological processes such as developmental timing, differentiation, cell death, stem cell proliferation and differentiation, immune response, aging and cancer. Accumulating studies in recent years suggest that miRNAs play crucial roles in stem cell division and differentiation. In the present chapter, we present a brief overview of these studies and discuss their contributions toward our understanding of the importance of miRNAs in normal and aged stem cell function in various model systems.

AIMP3 depletion causes genome instability and loss of stemness in mouse embryonic stem cells

Aminoacyl-tRNA synthetase-interacting multifunctional protein-3 (AIMP3) is a component of the multi-aminoacyl-tRNA synthetase complex and is involved in diverse cellular processes. Given that AIMP3 deficiency causes early embryonic lethality in mice, AIMP3 is expected to play a critical role in early mouse development. To elucidate a functional role of AIMP3 in early mouse development, we induced AIMP3 depletion in mouse embryonic stem cells (mESCs) derived from blastocysts of AIMP3^f/f; Cre^ERT2 mice. In the present study, AIMP3 depletion resulted in loss of self-renewal and ability to differentiate to three germ layers in mESCs. AIMP3 depletion led to accumulation of DNA damage by blocking double-strand break repair, in particular homologous recombination. Through microarray analysis, the p53 signaling pathway was identified as being activated in AIMP3-depleted mESCs. Knockdown of p53 rescued loss of stem cell characteristics by AIMP3 depletion in mESCs. These results imply that AIMP3 depletion in mESCs leads to accumulation of DNA damage and p53 transactivation, resulting in loss of stemness. We propose that AIMP3 is involved in maintenance of genome stability and stemness in mESCs.

Mesenchymal Stromal/Stem Cells in Regenerative Medicine and Tissue Engineering

As a result of over five decades of investigation, mesenchymal stromal/stem cells (MSCs) have emerged as a versatile and frequently utilized cell source in the fields of regenerative medicine and tissue engineering. In this review, we summarize the history of MSC research from the initial discovery of their multipotency to the more recent recognition of their perivascular identity in vivo and their extraordinary capacity for immunomodulation and angiogenic signaling. As well, we discuss long-standing questions regarding their developmental origins and their capacity for differentiation toward a range of cell lineages. We also highlight important considerations and potential risks involved with their isolation, ex vivo expansion, and clinical use. Overall, this review aims to serve as an overview of the breadth of research that has demonstrated the utility of MSCs in a wide range of clinical contexts and continues to unravel the mechanisms by which these cells exert their therapeutic effects.

Novel miRNA biomarkers for genotoxicity screening in mouse

The genotoxic potential of drugs is a serious problem, and its evaluation is one of the most critical processes of drug development. Although the comet assay of compound-exposed tissue is a frequently used genotoxicity test, its high false-positive rate is a major complication, and we consistently obtained false-positive results using the comet assay of mouse liver for nine hepatotoxic non-genotoxins (NGTXs). To identify novel genotoxin (GTX)-specific biomarkers, we screened the expression of 750 microRNAs (miRNAs) in the livers of mice treated with GTXs or NGTXs. Three miRNAs, miR-22-3p, miR-409-3p, and miR-543-3p, were significantly down-regulated in GTX-treated mouse liver. In contrast, these three miRNAs were significantly up-regulated in plasma. A discrimination model based on the expression levels of these biomarkers successfully identified GTXs and NGTXs. This novel biomarker expression-based discrimination model analysis using both liver and plasma is effective for detecting genotoxicity with high sensitivity and reliability to support drug development.

Inflammatory Stimuli Significantly Change the miRNA Profile of Human Adipose-Derived Stem Cells

Background

Human adipose-derived stem cells (hASCs) have been shown to have immunoregulatory properties in many studies. However, the mechanisms remain unknown. miRNAs are associated with many cellular processes, including immune responses. Thus, we hypothesized that miRNAs act as immunoregulators when hASCs are stimulated by inflammatory environments.

Methods

A set of cytokines was used to stimulate the hASCs in the cytokine group, while no cytokines were used to stimulate the cells in the normal group. A microarray was used to obtain the miRNA expression profile of hASCs, and RT-PCR was used to validate the miRNAs that were differentially expressed between the two groups. Target genes were predicted using online databases, and KEGG analysis was performed to identify the pathways enriched by the target genes of all the differentially expressed miRNAs.

Results

Five miRNAs were significantly upregulated, and 2 miRNAs were downregulated in the cytokine group compared with the normal group. We identified several immune-related pathways that are targeted individually or collectively by those miRNAs.

Conclusion

Inflammatory stimuli changed the miRNA expression profile of hASCs. miRNAs may play a pivotal role in the immune response in hASCs and may be targets through which the immunoregulatory functions of hASCs can be enhanced.

BMI1 inhibits senescence and enhances the immunomodulatory properties of human mesenchymal stem cells via the direct suppression of MKP-1/DUSP1

For the application of mesenchymal stem cells (MSCs) as clinical therapeutics, the regulation of cellular aging is important to protect hMSCs from an age-associated decline in their function. In this study, we evaluated the effects of hypoxia on cellular senescence and the immunomodulatory abilities of hUCB-MSCs. Hypoxic-cultured hUCB-MSCs showed enhanced proliferation and had increased immunosuppressive effects on mitogen-induced mononuclear cell proliferation. We found that BMI1, a member of the polycomb repressive complex protein group, showed increased expression in hypoxic-cultured hUCB-MSCs, and the further knock-down of BMI1 in hypoxic cells induced decreased proliferative and immunomodulatory abilities in hUCB-MSCs, along with COX-2/PGE₂ down-regulation. Furthermore, the expression of phosphorylated p38 MAP kinase increased in response to the over-expression of BMI1 in normoxic conditions, suggesting that BMI1 regulates the immunomodulatory properties of hUCB-MSCs via p38 MAP kinase-mediated COX-2 expression. More importantly, we identified BMI1 as a direct repressor of MAP kinase phosphatase-1 (MKP-1)/DUSP1, which suppresses p38 MAP kinase activity. In conclusion, our results demonstrate that BMI1 plays a key role in the regulation of the immunomodulatory properties of hUCB-MSCs, and we suggest that these findings might provide a strategy to enhance the functionality of hUCB-MSCs for use in therapeutic applications.

miR-590 promotes the proliferation of HUMSCs and induces ECM synthesis by targeting Smad7

MicroRNA (miR)-590 has been established to be a promoter of cell proliferation, migration and invasion, and an inhibitor of apoptosis in numerous cancer cell lines. However, its effects on non-cancer cells remain to be elucidated. miR-590 was transfected into human umbilical cord mesenchymal stem cells (HUMSCs), and the cell proliferation rate was determined using a Cell-Light 5-ethynyl-20-deoxyuridine Apollo 567 kit and the presence of extracellular matrix (ECM) proteins were detected using western blot analysis and immunofluorescence microscopy. Using bioinformatic analysis and dual-luciferase assays, the novel target miR-590 was identified. In addition, the effects of miR-590 on cell proliferation and ECM enhancement were also evaluated. The results of the present study demonstrated that miR-590 interacts directly with the 3'-untranslated region of Mothers Against Decapentaplegic Homolog 7 (Smad7), which is an important factor in transforming growth factor-β signaling pathway. Overexpression of miR-590 downregulated Smad7 expression at the mRNA and protein level, and subsequently resulted in cell proliferation and ECM accumulation. Additionally, the transfection of small interfering RNA targeting Smad7 in HUMSCs produced similar effects on cell proliferation and ECM to the overexpression of miR-590. The results of the present study indicated that miR-590 affects HUMSC proliferation by directly targeting Smad7.

DNA damage response (DDR) and senescence: shuttled inflamma-miRNAs on the stage of inflamm-aging

A major issue in aging research is how cellular phenomena affect aging at the systemic level. Emerging evidence suggests that DNA damage response (DDR) signaling is a key mechanism linking DNA damage accumulation, cell senescence, and organism aging. DDR activation in senescent cells promotes acquisition of a proinflammatory secretory phenotype (SASP), which in turn elicits DDR and SASP activation in neighboring cells, thereby creating a proinflammatory environment extending at the local and eventually the systemic level. DDR activation is triggered by genomic lesions as well as emerging bacterial and viral metagenomes. Therefore, the buildup of cells with an activated DDR probably fuels inflamm-aging and predisposes to the development of the major age-related diseases (ARDs). Micro (mi)-RNAs - non-coding RNAs involved in gene expression modulation - are released locally and systemically by a variety of shuttles (exosomes, lipoproteins, proteins) that likely affect the efficiency of their biological effects. Here we suggest that some miRNAs, previously found to be associated with inflammation and senescence - miR-146, miR-155, and miR-21 - play a central role in the interplay among DDR, cell senescence and inflamm-aging. The identification of the functions of shuttled senescence-associated miRNAs is expected to shed light on the aging process and on how to delay ARD development.

IGF-1 deficiency in a critical period early in life influences the vascular aging phenotype in mice by altering miRNA-mediated post-transcriptional gene regulation: implications for the developmental origins of health and disease hypothesis

Epidemiological findings support the concept of Developmental Origins of Health and Disease, suggesting that early-life hormonal influences during a sensitive period of development have a fundamental impact on vascular health later in life. The endocrine changes that occur during development are highly conserved across mammalian species and include dramatic increases in circulating IGF-1 levels during adolescence. The present study was designed to characterize the effect of developmental IGF-1 deficiency on the vascular aging phenotype. To achieve that goal, early-onset endocrine IGF-1 deficiency was induced in mice by knockdown of IGF-1 in the liver using Cre-lox technology (Igf1 ^f/f mice crossed with mice expressing albumin-driven Cre recombinase). This model exhibits low-circulating IGF-1 levels during the peripubertal phase of development, which is critical for the biology of aging. Due to the emergence of miRNAs as important regulators of the vascular aging phenotype, the effect of early-life IGF-1 deficiency on miRNA expression profile in the aorta was examined in animals at 27 months of age. We found that developmental IGF-1 deficiency elicits persisting late-life changes in miRNA expression in the vasculature, which significantly differed from those in mice with adult-onset IGF-1 deficiency (TBG-Cre-AAV8-mediated knockdown of IGF-1 at 5 month of age in Igf1 ^f/f mice). Using a novel computational approach, we identified miRNA target genes that are co-expressed with IGF-1 and associate with aging and vascular pathophysiology. We found that among the predicted targets, the expression of multiple extracellular matrix-related genes, including collagen-encoding genes, were downregulated in mice with developmental IGF-1 deficiency. Collectively, IGF-1 deficiency during a critical period during early in life results in persistent changes in post-transcriptional miRNA-mediated control of genes critical targets for vascular health, which likely contribute to the deleterious late-life cardiovascular effects known to occur with developmental IGF-1 deficiency.

Peroxisome proliferator-activated receptor-γ agonist inhibits collagen synthesis in human keloid fibroblasts by suppression of early growth response-1 expression through upregulation of miR-543 expression

A keloid is a benign skin tumor formed by an overgrowth of granulation tissue in affected patients. Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists were reported to be able to regulate extracellular matrix production in human dermal fibroblasts. This study explored the underlying molecular mechanism of PPAR-γ agonist troglitazone treatment for fibroblasts obtained from keloid patients. The data revealed that troglitazone treatment of keloid fibroblasts (KFs) downregulated the expression of early growth response-1 (Egr1) and collagen-1 (Col1). Level of Egr1 were closely associated with KF-induced fibrosis. The miRNA profiling data revealed that miR-543 was transcriptionally activated after troglitazone treatment. Bioinformatic analysis and experimental data showed that miR-543 was able to target Egr1. ELISA data confirmed that Col1 protein in the supernatant were modulated by the feedback regulatory axis of PPAR-γ agonist-induced miR-543 to inhibit Egr1 expression, whereas PPAR-γ antagonist treatment abolished such effect on Col1 suppression in KFs. This study demonstrated that the PPAR-γ agonist-mediated miR-543 and Egr1 signaling plays an important role in the suppression of collagen synthesis in KFs. Future in vivo studies are needed to confirm these in vitro data.

The enigma of ceramide synthase regulation in mammalian cells

Ceramide synthases (CerS) are key enzymes in the lipid metabolism of eukaryotic cells. Their products, ceramides (Cer), are components of cellular membranes but also mediate signaling functions in physiological processes such as proliferation, skin barrier function and cerebellar development. In pathophysiological processes such as multiple sclerosis and tumor progression, ceramide levels are altered, which can be ascribed, partly, to dysregulation of CerS gene transcription. Most publications deal with the effects of altered ceramide levels on physiological and pathophysiological processes, but the regulation of the appropriate CerS is frequently not investigated. This is insufficient for the clarification of the role of ceramides, because most ceramide species are generated by at least two CerS. The mechanisms of CerS regulation are manifold and it seems that each CerS isoform is regulated individually. For this reason, we discuss the different CerS separately in this review. From transcriptional regulation to alteration of protein activity, the possibilities to influence CerS are diverse. Furthermore, CerS are influenced by a variety of molecules including hormones and lipids. Without claiming completeness, we provide a résumé of the regulatory mechanisms for each CerS in mammalian cells and how dysregulation of these mechanisms during physiological processes may lead to pathophysiological processes.

microRNA expression changes after atrial fibrillation catheter ablation

Atrial fibrillation (AF) is most common arrhythmia in general population, with increasing trend in mortality and morbidity. Electrophysiological and structural abnormalities, promoting abnormal impulse formation and propagation, lead to this disease. AF catheter ablation is related to a not small percentage of nonresponder patients. microRNAs (miRs) have been used as AF fibrotic and electrical alterations biomarkers. miRs may differentiate responders patients to ablative approach. Selective miR target therapy, as upregulation by adenovirus transfection and/or miR downregulation by antagomiR, may be used to treat AF patients. Catheter ablation of triggering electrical pulmonary veins activity or fibrotic areas defragmentation may be upgraded by miR therapy to prevent cardiac electrical and fibrotic remodeling after AF ablation.

miR-590-3p Is a Novel MicroRNA in Myocarditis by Targeting Nuclear Factor Kappa-B in vivo

OBJECTIVE

Nuclear factor kappa-B (NF-954;B)-induced inflammation leads to myocarditis and heart dysfunction. How microRNAs (miRNAs) contribute to this process is poorly defined. The aim of this study was to investigate whether miRNAs regulate NF-954;B-induced inflammation in experimental autoimmune myocarditis (EAM) in vivo.

METHODS AND RESULTS

NF-954;B and its related proinflammatory genes, including interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a), were activated in EAM. Profiling of NF-954;B-related miRNAs revealed that miR-590-3p was strikingly reduced in EAM. We found IL-6-induced proinflammatory signaling via miR-590-3p reduction, p50 induction, NF-954;B activation and IL-6/TNF-a expression. Moreover, a luciferase reporter assay demonstrated that miR-590-3p directly interacted with the 3' UTR (untranslated region) of the p50 subunit, and that miR-590-3p overexpression inhibited p50 expression. Finally, miR-590-3p transfection through adeno-associated virus significantly inhibited p50 expression, suppressed NF-954;B activity and blocked IL-6/TNF-a expression in vivo, reducing the lesion area and improving cardiac function in EAM.

CONCLUSION

miR-590-3p is a novel NF-954;B-related miRNA that directly targets the p50 subunit. This may provide a novel strategy for the treatment of myocarditis.