Analysis of differentially expressed microRNA of TNF-α-stimulated mesenchymal stem cells and exosomes from their culture supernatant

Therapeutic trends of priming mesenchymal stem cells: A bibliometric analysis

Mesenchymal stem cells (MSCs) have gained substantial attention in regenerative medicine due to their multilineage differentiation potential and immunomodulatory capabilities. MSCs have demonstrated therapeutic promise in numerous preclinical and clinical studies across a variety of diseases, including neurodegenerative disorders, cardiovascular diseases, and autoimmune conditions. Recently, priming MSCs has emerged as a novel strategy to enhance their therapeutic efficacy by preconditioning them for optimal survival and function in challenging in vivo environments. This study presented a comprehensive bibliometric analysis of research activity in the field of priming mesenchymal stem cells (MSCs) from 2003 to 2023. Utilizing a dataset of 585 documents, we explored research trends, leading authors and countries, productive journals, and frequently used keywords. We also explored priming strategies to augment the therapeutic efficacy of MSCs. Our findings show increasing research productivity with a peak in 2019, identified the United States as the leading contributor, and highlighted WANG JA as the most prolific author. The most published journal was Stem Cell Research & Therapy. Keyword analysis revealed core research areas emerging hotspots, while coword and cited sources visualizations elucidated the conceptual framework and key information sources. Further studies are crucial to advance the translation of primed MSCs from bench to bedside, potentially revolutionizing the landscape of regenerative medicine.

Optimization of exosome-based cell-free strategies to enhance endogenous cell functions in tissue regeneration

Exosomes, nanoscale extracellular vesicles, play a crucial role in intercellular communication, owing to their biologically active cargoes such as RNAs and proteins. In recent years, they have emerged as a promising tool in the field of tissue regeneration, with the potential to initiate a new trend in cell-free therapy. However, it's worth noting that not all types of exosomes derived from cells are appropriate for tissue repair. Thus, selecting suitable cell sources is critical to ensure their efficacy in specific tissue regeneration processes. Current therapeutic applications of exosomes also encounter several limitations, including low-specific content for targeted diseases, non-tissue-specific targeting, and short retention time due to rapid clearance in vivo. Consequently, this review paper focuses on exosomes from diverse cell sources with functions specific to tissue regeneration. It also highlights the latest engineering strategies developed to overcome the functional limitations of natural exosomes. These strategies encompass the loading of specific therapeutic contents into exosomes, the endowment of tissue-specific targeting capability on the exosome surface, and the incorporation of biomaterials to extend the in vivo retention time of exosomes in a controlled-release manner. Collectively, these innovative approaches aim to synergistically enhance the therapeutic effects of natural exosomes, optimizing exosome-based cell-free strategies to boost endogenous cell functions in tissue regeneration. STATEMENT OF SIGNIFICANCE: Exosome-based cell-free therapy has recently emerged as a promising tool for tissue regeneration. This review highlights the characteristics and functions of exosomes from different sources that can facilitate tissue repair and their contributions to the regeneration process. To address the functional limitations of natural exosomes in therapeutic applications, this review provides an in-depth understanding of the latest engineering strategies. These strategies include optimizing exosomal contents, endowing tissue-specific targeting capability on the exosome surface, and incorporating biomaterials to extend the in vivo retention time of exosomes in a controlled-release manner. This review aims to explore and discuss innovative approaches that can synergistically improve endogenous cell functions in advanced exosome-based cell-free therapies for a broad range of tissue regeneration.

Exosomes from TNF-α preconditioned human umbilical cord mesenchymal stromal cells inhibit the autophagy of acinar cells of severe acute pancreatitis via shuttling bioactive metabolites

Severe acute pancreatitis (SAP) is a common critical disease of the digestive system, with high mortality and a lack of effective prevention and treatment measures. Despite mesenchymal stromal cell transplantation having the potential to treat SAP, its clinical application prospect is limited, and the mechanism is unclear. Here, we reveal the therapeutic role of exosomes from TNF-α-preconditioned human umbilical cord mesenchymal stromal cells (HUCMSCs) in attenuating SAP and show that it is partly dependent on exosomal metabolites. Bioactive metabolomics analysis showed that 48 metabolites be significantly differentially expressed between the two groups (Exo-Ctrl group versus Exo-TNF-α group). Then, the further functional experiments indicated that 3,4-dihydroxyphenylglycol could be a key molecule mediating the therapeutic effect of TNF-α-preconditioned HUCMSCs. The animal experiments showed that 3,4-dihydroxyphenylglycol reduced inflammation and oxidative stress in the pancreatic tissue and inhibited acinar cell autophagy in a rat model of SAP. Mechanistically, we revealed that 3,4-dihydroxyphenylglycol activated the mTOR pathway to inhibit acinar cell autophagy and alleviate SAP. In summary, our study demonstrated that exosomes from TNF-α-preconditioned HUMSCs inhibit the autophagy of acinar cells of SAP by shuttling 3,4-dihydroxyphenylglycol and inhibiting the mTOR pathway. This study revealed the vital role and therapeutic potential of metabolite-derived exosomes in SAP, providing a new promising method to prevent and therapy SAP.

Enhancers of mesenchymal stem cell stemness and therapeutic potency

Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into a range of cell types, including osteoblasts, chondrocytes, myocytes, and adipocytes. Multiple preclinical investigations and clinical trials employed enhanced MSCs-dependent therapies in treatment of inflammatory and degenerative diseases. They have demonstrated considerable and prospective therapeutic potentials even though the large-scale use remains a problem. Several strategies have been used to improve the therapeutic potency of MSCs in cellular therapy. Treatment of MSCs utilizing pharmaceutical compounds, cytokines, growth factors, hormones, and vitamins have shown potential outcomes in boosting MSCs' stemness. In this study, we reviewed the current advances in enhancing techniques that attempt to promote MSCs' therapeutic effectiveness in cellular therapy and stemness in vivo with potential mechanisms and applications.

The direct effect of lipopolysaccharide on an isolated heart is different from the effect on cardiac myocytes in vitro

INTRODUCTION

Lipopolysaccharide (LPS) is widely used to induce experimental animals. However, its effects on cardiac contraction is controversial. Although LPS probably induces its influence in vivo both directly and indirectly, we focused on the direct effects of LPS in this report.

MATERIAL AND METHODS

Isolated ventricular myocytes mounted on a Langendorff apparatus were perfused with LPS. The changes in cultured H9c2 cells incubated with LPS over a 3-h exposure were compared with the changes after a 24-h incubation. Apoptosis was identified using flow cytometry and Western blotting. The mRNA levels were also determined.

RESULTS

LPS directly stimulated cardiac contractility at low doses, although it produced inhibition at higher doses. The TLR4-coupled JAK2/STAT3 pathway was identified in H9c2 cells after LPS treatment, with an increase in intracellular calcium levels. LPS dose-dependently activated hypertrophic signals in H9c2 cells and induced apoptosis at the high dose. However, apoptosis was observed in H9c2 cells after a 24-h exposure to LPS, even at low doses. This observation appears to be associated with the level of paracrine cytokines. Changes in H9c2 cells by LPS were diminished by NPS2390, an inhibitor of the calcium-sensing receptor (CaSR). LPS also promoted CaSR mRNA expression in H9c2 cells, which may be unrelated to the changes in cytokine expression influenced by an inflammasome inhibitor.

CONCLUSIONS

In contrast to the isolated hearts, LPS activated hypertrophic signals prior to apoptotic signals in cardiac cells. Thus, LPS injury appears to be associated with CaSR, which was not markedly influenced by an inflammasome inhibitor.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: The Novel Therapeutic Option for Regenerative Dentistry

Dental mesenchymal stem cells (MSCs) are characterized by unlimited self-renewal ability and high multidirectional differentiation potential. Since dental MSCs can be easily isolated and exhibit a high capability to differentiate into odontogenic cells, they are considered as attractive therapeutic agents in regenerative dentistry. Recently, MSC-derived extracellular vesicles (MSC-EVs) have attracted widespread attention as carriers for cell-free therapy due to their potential functions. Many studies have shown that MSC-EVs can mediate microenvironment at tissue damage site, and coordinate the regeneration process. Additionally, MSC-EVs can mediate intercellular communication, thus affecting the phenotypes and functions of recipient cells. In this review, we mainly summarized the types of MSCs that could be potentially applied in regenerative dentistry, the possible molecular cargos of MSC-EVs, and the major effects of MSC-EVs on the therapeutic induction of osteogenic differentiation.

Circulating Extracellular Vesicles in Stroke Patients Treated With Mesenchymal Stem Cells: A Biomarker Analysis of a Randomized Trial

Background:

Mesenchymal stem cells (MSCs) secrete trophic factors and extracellular vesicles (EVs). However, the level and role of EVs after MSC therapy in patients with stroke are unknown. We investigated whether circulating EVs and trophic factors are increased after MSCs and are related to the therapeutic benefits in the STARTING-2 trial (Stem Cell Application Researches and Trials in Neurology-2) participants.

Methods:

In this prospective randomized controlled trial, patients with chronic major stroke were assigned, in a 2:1 ratio, to receive autologous MSC intravenous injection (MSC group, n=39) or standard treatment (control group, n=15) and followed for 3 months. Detailed clinical assessment and neuroplasticity on diffusion tensor image and resting-state functional magnetic resonance imaging were evaluated. Serial samples were collected, before/after MSCs therapy. The primary outcome measure was circulating factors that are associated with the clinical improvement in the Fugl-Meyer Assessment (secondary end point of the trial) and neuroplasticity on diffusion tensor image and resting-state functional magnetic resonance imaging. Additional outcome measures were microRNAs and trophic factors enriched in the plasma EVs, obtained using quantitative polymerase chain reaction and ELISA, respectively.

Results:

Circulating EV levels were increased ≈5-fold (mean±SD, from 2.7×10 9 ±2.2×10 9 to 1.3×10 10 ±1.7×10 10 EVs/mL) within 24 hours after injection of MSCs ( P =0.001). After adjustment of age, sex, baseline stroke severity, and the time interval from stroke onset to treatment, only the EV number was independently associated with improvement in motor function (odds ratio, 5.718 for EV number Log [95% CI, 1.144–28.589]; P =0.034). Diffusion tensor image and resting-state functional magnetic resonance imaging showed that integrity of the ipsilesional corticospinal tract and intrahemispheric motor network were significantly correlated with circulating EV levels, respectively ( P <0.05). MicroRNAs related to neurogenesis/neuroplasticity (eg, microRNA-18a-5p) were significantly increased in circulating EVs after MSC therapy ( P =0.0479). In contrast, trophic factor levels were not changed after MSC therapy.

Conclusions:

This trial is the first to show that treatment of ischemic stroke patients with MSCs significantly increases circulating EVs, which were significantly correlated with improvement in motor function and magnetic resonance imaging indices of plasticity.

Registration:

URL: https://www.clinical trials.gov ; Unique identifier: NCT01716481.

The let-7f-5p-Nme4 pathway mediates tumor necrosis factor α-induced impairment in osteogenesis of bone marrow-derived mesenchymal stem cells

Although tumor necrosis factor α (TNF-α)-mediated inflammation significantly impacts osteoporosis, the mechanisms underlying the osteogenic differentiation defects of bone marrow-derived mesenchymal stem cells (BM-MSCs) caused by TNF-α remain poorly understood. We found that TNF-α stimulation of murine BM-MSCs significantly upregulated the expression levels of several microRNAs (miRNAs), including let-7f-5p, but this increase was significantly reversed by treatment with the kinase inhibitor BAY 11-7082. To study gain- or loss of function, we transfected cells with an miRNA inhibitor or miRNA mimic. We then demonstrated that let-7f-5p impaired osteogenic differentiation of BM-MSCs in the absence and presence of TNF-α, as evidenced by alkaline phosphatase and alizarin red staining as well as quantitative assays of the mRNA levels of bone formation marker genes in differentiated BM-MSCs. Moreover, let-7f-5p targets the 3' untranslated region of Nucleoside diphosphate kinase 4 (Nme4) mRNA and negatively regulates Nme4 expression in mouse BM-MSCs. Ectopic expression of Nme4 completely reversed the inhibitory effects of the let-7f-5p mimic on osteogenic differentiation of mouse BM-MSCs. Furthermore, inhibition of let-7f-5p or overexpression of Nme4 in BM-MSCs restored in-vivo bone formation in an ovariectomized animal model. Collectively, our work indicates that let-7f-5p is involved in TNF-α-mediated reduction of BM-MSC osteogenesis via targeting Nme4.

miR-155 Contributes to the Immunoregulatory Function of Human Mesenchymal Stem Cells

Objectives

Mesenchymal stem/stromal cells (MSCs) are widely investigated in regenerative medicine thanks to their immunomodulatory properties. They exert their anti-inflammatory function thanks to the secretion of a number of mediators, including proteins and miRNAs, which can be released in the extracellular environment or in the cargo of extracellular vesicles (EVs). However, the role of miRNAs in the suppressive function of MSCs is controversial. The aim of the study was to identify miRNAs that contribute to the immunomodulatory function of human bone marrow-derived MSCs (BM-MSCs).

Methods

Human BM-MSCs were primed by coculture with activated peripheral blood mononuclear cells (aPBMCs). High throughput miRNA transcriptomic analysis was performed using Human MicroRNA TaqMan® Array Cards. The immunosuppressive function of miRNAs was investigated in mixed lymphocyte reactions and the delayed type hypersensitivity (DTH) murine model.

Results

Upon priming, 21 out of 377 tested miRNAs were significantly modulated in primed MSCs. We validated the up-regulation of miR-29a, miR-146a, miR-155 and the down-regulation of miR-149, miR-221 and miR-361 in additional samples of primed MSCs. We showed that miR-155 significantly reduced the proliferation of aPBMCs in vitro and inflammation in vivo, using the DTH model. Analysis of miRNA-mRNA interactions revealed miR-221 as a potential target gene that is down-regulated by miR-155 both in primed MSCs and in aPBMCs.

Conclusion

Here, we present evidence that miR-155 participates to the immunosuppressive function of human BM-MSCs and down-regulates the expression of miR-221 as a possible inflammatory mediator.

The effect of the WKYMVm peptide on promoting mBMSC secretion of exosomes to induce M2 macrophage polarization through the FPR2 pathway

Background

When multicystic vesicles (precursors of exosomes) are formed in cells, there are two results. One is decomposition by lysosomes, and the other is the generation of exosomes that are transported out through the transmembrane. On the other hand, M2 macrophages promote the formation of local vascularization and provide necessary support for the repair of bone defects. To provide a new idea for the treatment of bone defects, the purpose of our study was to investigate the effect of WKYMVm (Trp-Lys-Tyr-Met-Val-D-Met-NH2) peptide on the secretion of exosomes from murine bone marrow-derived MSCs (mBMSCs) and the effect of exosomes on the polarization of M2 macrophages.

Methods

The WKYMVm peptide was used to activate the formyl peptide receptor 2 (FPR2) pathway in mBMSCs. First, we used Cell Counting Kit-8 (CCK-8) to detect the cytotoxic effect of WKYMVm peptide on mBMSCs. Second, we used western blotting (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) to detect the expression of interferon stimulated gene 15 (ISG15) and transcription factor EB (TFEB) in mBMSCs. Then, we detected lysosomal activity using a lysozyme activity assay kit. Third, we used an exosome extraction kit and western blotting to detect the content of exosomes secreted by mBMSCs. Fourth, we used immunofluorescence and western blotting to count the number of polarized M2 macrophages. Finally, we used an inhibitor to block miRNA-146 in exosomes secreted by mBMSCs and counted the number of polarized M2 macrophages.

Results

We first found that the WKYMVm peptide had no toxic effect on mBMSCs at a concentration of 1 μmol/L. Second, we found that when the FPR2 pathway was activated by the WKYMVm peptide in mBMSCs, ISG15 and TFEB expression was decreased, leading to increased secretion of exosomes. We also found that lysosomal activity was decreased when the FPR2 pathway was activated by the WKYMVm peptide in mBMSCs. Third, we demonstrated that exosomes secreted by mBMSCs promote the polarization of M2 macrophages. Moreover, all these effects can be blocked by the WRWWWW (WRW4, H-Trp-Arg-Trp-Trp-Trp-Trp-OH) peptide, an inhibitor of the FPR2 pathway. Finally, we confirmed the effect of miRNA-146 in exosomes secreted by mBMSCs on promoting the polarization of M2 macrophages.

Conclusion

Our findings demonstrated the potential value of the WKYMVm peptide in promoting the secretion of exosomes by mBMSCs and eventually leading to M2 macrophage polarization. We believe that our study could provide a research basis for the clinical treatment of bone defects.

TL1A/TNFR2 Axis Enhances Immunoregulatory Effects of Bone Marrow Derived Mesenchymal Stem Cell by Indian Hedgehog Signaling Pathway

Background and Objectives

The immunomodulatory potential of mesenchymal stem cells (MSCs) can be regulated by a variety of molecules, especially cytokines. The inflammatory cytokine, TNF-like ligand 1A (TL1A), has been reported as an inflammation stimulator in-multiple autoimmune diseases. Here, we studied the effects of TL1A/TNF-receptor 2 (TNFR2) pathway on the therapeutic potency of bone marrow-derived MSCs (BMSCs).

Methods and Results

BMSCs, fibroblast-like synoviocytes (FLSs), and H9 and jurkat human T lymphocytes were used in this study. BMSCs paracrine activities, differentiation, proliferation, and migration were investigated after stimulation with TL1A, and intervened with anti-TNFR2. Additionally, the effects of TL1A on BMSCs therapeutic potency were evaluated by treating RA-FLSs, and H9 and jurkat T cells with TL1A-stimulated BMSCs conditioned medium (CM). Indian hedgehog (IHH) involvement was determined by gene silencing and treatment by recombinant IHH (rIHH). TL1A induced BMSCs stemness-related genes, COX-2, IL-6, IDO, TGF-β and HGF through TNFR2. Also, TL1A corrected biased differentiation and increased proliferation, and migration through TNFR2. Meanwhile, CM of TL1A-stimulated BMSCs decreased the inflammatory markers of RA-FLSs and T cells. Moreover, TL1A-stimulated BMSCs experienced IHH up-regulation coupled with NF-κB and STAT3 signaling up-regulation, while p53 and oxidative stress were down-regulated. Furthermore, treatment of BMSCs by rIHH increased their anti-inflammatory effects. More importantly, knockdown of IHH decreased the ability of TL1A-stimulated BMSCs to alleviating the inflammation in RA-FLSs and T cells.

Conclusions

This study reports the effects of TL1A/TNFR2 pathway on the biological behaviors and therapeutic potency of BMSCs through IHH. These findings could introduce novel procedures to increase the stemness of MSCs in cellular therapy.

Serum microRNA profiles in patients with autosomal dominant polycystic kidney disease show systematic dysregulation partially reversible by hemodialysis

INTRODUCTION

The impact of autosomal dominant polycystic kidney disease (ADPKD) on serum microRNAs (miRNA) is unknown.

MATERIAL AND METHODS

For profiling experiment we recruited 30 patients from three equinumerous groups: controls, ADPKD and ADPKD on hemodialysis. From the last group extra samples were collected for in pre-/postdialysis analysis. Additionally, 23 healthy volunteers were used for selected biomarker verification. Real-time PCR arrays were used for quantification of 752 miRNAs. Validation of selected miRNAs was performed in total RNA extracted from the serum and the exosomal fraction in pre-/postdialysis samples.

RESULTS

In total, 37 significant circulating miRNAs were found to differ between ADPKD patients and controls. In validation, 3 miRNAs with the highest fold change in comparison of dialyzed vs non-dialyzed patients (miR-532-3p, miR-320b, miR-144-5p) were not significantly altered by hemodialysis and from the top down-regulated ones, miR-27a-3p was significantly lower after dialysis in both total and exosomal fractions, miR-20a-5p was down-regulated in the exosomal fraction and miR-16-5p was unaltered by hemodialysis. MiR-16-5p was selected as the best circulating biomarker of ADPKD. Circulating representatives of the miR-17 family sharing the same seed region (miR-20a-5p, miR-93-5p and miR-106a-5p) showed significantly lower expression among dialyzed vs. non-dialyzed patients and their exosomal fraction dropped after hemodialysis.

CONCLUSIONS

The serum miRNAs among ADPKD patients differ substantially depending on the stage of CKD. The exosomal fraction of miRNA was more affected by dialysis than the total one. There was a common pattern of down-regulation for circulating miR-17 family members sharing the same seed region.

Upregulated ox40l Can Be Inhibited by miR-146a-5p in Condylar Chondrocytes Induced by IL-1β and TNF-α: A Possible Regulatory Mechanism in Osteoarthritis

INTRODUCTION

Osteoarthritis (OA) is a common musculoskeletal disease characterized by pain, stiffness, limited activity, occasional effusion, and local inflammation. MiR-146 is one of the noncoding RNA closely related to OA, but the role of miR-146 in OA remains controversial. The tumour necrosis factor receptor OX40 is activated by its cognate ligand OX40L (TNFSF4) and functions as a T-cell costimulatory molecule. The T-cell functions, including cytokine production, expansion, and survival, are enhanced by the OX40 costimulatory signals.

METHODS

We established an inflammatory model of condylar chondrocytes induced by IL-1β and TNF-α and detected the expression of miRNA by miRNA sequencing. Then, cell transfection was used to study the role of miR146a-5p in OA. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and database analysis were used to screen out potential target genes of miR-146a-5p. A dual luciferase activity assay tested whether ox40l is the target gene of miR-146a-5p.

RESULTS

MiR-146a-5p and OX40L was upregulated after induced by IL-1β and TNF-α, miR-146a-5p reduced the production of inflammatory factors but had no effect on chondrophenotypic factors, and ox40l was targeted by miR-146a-5p.

CONCLUSION

OX40L and miR-146a-5p of condylar chondrocytes in the inflammatory environment (induced by IL-1β and TNF-α) were significantly increased, miR-146a-5p is a protective factor in the inflammatory response, which can reduce the production of inflammatory factors, and miR-146a-5p may regulate T-cell-mediated immunity through targeting of ox40l in OA.

MiR-200b in heme oxygenase-1-modified bone marrow mesenchymal stem cell-derived exosomes alleviates inflammatory injury of intestinal epithelial cells by targeting high mobility group box 3

Heme Oxygen-1 (HO-1)-modified bone marrow mesenchymal stem cells (BMMSCs) are effective to protect and repair transplanted small bowel and intestinal epithelial cells (IECs); however, the mechanism and the role of HO-1/BMMSCs-derived exosomes is unclear. In the present study, we aimed to verify that exosomes from a HO-1/BMMSCs and IEC-6 cells (IEC-6s) co-culture system could reduce the apoptosis of IEC-6s and decrease the expression of the tight junction protein, zona occludens 1, in the inflammatory environment. Using mass spectrometry, we revealed that high mobility group box 3 (HMGB3) and phosphorylated c-Jun NH2-terminal kinase (JNK), under the influence of differentially abundant proteins identified through proteomic analysis, play critical roles in the mechanism. Further studies indicated that microRNA miR-200b, which was upregulated in exosomes derived from the co-culture of HO-1/BMMSCs and IEC-6s, exerted its role by targeting the 3′ untranslated region of Hmgb3 in this biological process. Functional experiments confirmed that miR-200b overexpression could reduce the inflammatory injury of IEC-6s, while intracellular miR-200b knockdown could significantly block the protective effect of HO-1/BMMSCs exosomes on the inflammatory injury of IEC-6s. In addition, the level of miR-200b in cells and exosomes derived from HO-1/BMMSCs stimulated by tumor necrosis factor alpha was significantly upregulated. In a rat small bowel transplantation model of allograft rejection treated with HO-1/BMMSCs, we confirmed that the level of miR-200b in the transplanted small bowel tissue was increased significantly, while the level of HMGB3/JNK was downregulated significantly. In conclusion, we identified that exosomes derived from HO-1/BMMSCs play an important role in alleviating the inflammatory injury of IECs. The mechanism is related to miR-200b targeting the abnormally increased expression of the Hmgb3 gene in IECs induced by inflammatory injury. The reduced level of HMGB3 then decreases the inflammatory injury.

Pretreatment of exosomes derived from hUCMSCs with TNF-α ameliorates acute liver failure by inhibiting the activation of NLRP3 in macrophage

AIMS

The management of acute liver failure (ALF) is a major challenge worldwide. The current study aimed to determine the therapeutic potential of TNF-α pretreatment of umbilical cord mesenchymal stem cell-derived exosomes (T-Exo) in ALF.

MAIN METHODS

Here, we enriched T-Exo and untreated exosomes (Exo), them were measured by nanoparticle tracking analysis (NTA) for particle size detection and identified surface marker by Western blot and flow cytometry. Then the cell proliferation was detected by CCK-8 and the effect of T-Exo on the expression levels of pro-inflammatory cytokines was tested by ELISA. ALF mouse models were induced by LPS and D-GalN. H&E staining, immunohistochemistry, and Western blot were used to detect the effect of T-Exo on the levels of NLRP3 and other inflammation-related pathway proteins. qPCR was used to detect the expression level of microRNA-299-3p in T-Exo and its transfer to macrophages. Laser confocal microscopy was used to detect colocalization of exosomes,Golgi and NLRP3 in macrophages.

KEY FINDINGS

Our study shows that T-Exo can reduce serum ALT, AST and proinflammatory cytokines level and inhibit activation of NLRP3 inflammation-associated pathway proteins. T-Exo treatment reduces pathological liver damage caused by ALF. Anti-inflammatory-related miRNA-299-3p is up-regulated in TNF-α-stimulated MSCs and selectively packaged into exosomes for role in exosomal treatment. And conducted preliminary exploration and hypothesis on the specific mechanism of this effect.

SIGNIFICANCE

These in vitro and in vivo studies indicate that T-Exo attenuates inflammatory damage caused by ALF and promotes liver tissue repair by inhibiting the activation of the NLRP3 pathway.

Mechanisms supporting potential use of bone marrow-derived mesenchymal stem cells in psychocardiology

Despite great efforts made in recent years, globally cardiovascular disease (CVD) remains the most common and devastating disease. Pharmacological, interventional and surgical treatments have proved to be only partly satisfactory for the majority of patients. A major underlying cause of poor prognosis is a high comorbidity rate between CVD and mental illness, which calls for the approaches of psychocardiology. As psychiatric disorders and CVD can influence each other bidirectionally, it is necessary to develop novel therapies targeting both systems simultaneously. Therefore, innovative stem cell (SC) therapy has become the most promising treatment strategy in psychocardiology. Bone marrow-derived mesenchymal stem/stromal cells (BM-MSCs), among all different types of SCs, have drawn the most attention due to unique advantages in terms of ethical considerations, low immunogenicity and simplicity of preparation. In this review, we survey recent publications and clinical trials to summarize the knowledge and progress gained so far. Moreover, we discuss the feasibility of the clinical application of BM-MSCs in the area of psychocardiology.

Hypoxic-conditioned medium from adipose tissue mesenchymal stem cells improved neuroinflammation through alternation of toll like receptor (TLR) 2 and TLR4 expression in model of Alzheimer's disease rats

Microglia have a pivotal role to initiate immune responses in AD brains through toll-like receptors and induce neuroinflammation. Adipose tissue mesenchymal stem cells (ATSCs) secret many neurotrophic and anti-inflammatory factors called conditioned medium (CM). Many studies have demonstrated that CM of mesenchymal stem cells facilitate regeneration and attenuates inflammation in many disorders. To this purpose, the effect of ATSCs-conditioned medium (ATSC-CM) on brain inflammation and the role of toll-like receptors were investigated in this study. Seventy-two rats were randomly divided into 6 groups: control, sham, sham+ATSC-CM: 200μl ATSC-CM once a day intraperitoneally for 8 days, AD group injected the Aβ1-40 intra-hippocampal, AD+ASC-CM, which was injected Aβ1-40 intra-hippocampal and 200μl ATSC-CM once a day intraperitoneally for 8 days and AD+ rivastigmine: was injected Aβ1-40 intra-hippocampal and received rivastigmine (0.6 mg/kg) orally once a day for 2 weeks. Memory and learning were measured by Morris water maze and novel object recognition tests. For detection of beta-amyloid plaque, Congo red staining was used, and neuronal survival was assessed by Nissl staining. Expression of TLR2 and TLR4 was measured by real-time PCR, and finally, to assess inflammation markers (IL-1β and TNF-α) in the hippocampus, ELISA kits were used. In treatment group spatial and recognition memory significantly was improved. ATSC-CM administration decreased beta amyloid plaques and enhanced neuronal survival in AD brain rats. In addition, TLR2 and TLR4 expression decreased in treatment group. Results also showed that ATSC-CM reduced IL-1β and TNF-α as inflammation markers. ATSC-CM improved memory deficit, decreased beta amyloids formation, increased neuron survival, and attenuated inflammation by reducing the expression of TLRs.

miR‑146a‑5p suppresses ATP‑binding cassette subfamily G member 1 dysregulation in patients with refractory Mycoplasma pneumoniae via interleukin 1 receptor‑associated kinase 1 downregulation

In the present study, we examined the function of microRNA (miR)-146a-5p in patients with refractory Mycoplasma pneumoniae pneumonia. In brief, the expression of miR-146a-5p was reduced in patients with refractory Mycoplasma pneumoniae pneumonia. Downregulation of miR-146a-5p reduced inflammation in an in vitro model of refractory Mycoplasma pneumoniae pneumonia, whilst overexpression of miR-146a-5p promoted inflammation. Downregulation of miR-146a-5p induced the protein expression of ATP-binding cassette subfamily G member 1 (ABCG1) and interleukin 1 receptor-associated kinase 1 (IRAK-1), while suppressed expression was observed of the aforementioned proteins following overexpression of miR-146a-5p in an in vitro model of refractory Mycoplasma pneumoniae pneumonia. The administration of small interfering RNA against RXR or IRAK-1 attenuated the effects of miR-146a-5p on inflammation in an in vitro model of refractory Mycoplasma pneumoniae pneumonia. Collectively, these results suggested that miR-146a-5p reduced ABCG1 expression in refractory Mycoplasma pneumoniae pneumonia via downregulation of IRAK-1.

Therapeutic effect of mesenchymal stem cells derived from human umbilical cord in rabbit temporomandibular joint model of osteoarthritis

Osteoarthritis (OA) is a degenerative condition of the temporomandibular joint (TMJ) characterised by chronic inflammation and damage to joint structures. Because of the complexity of TMJ-OA, only symptomatic treatments are currently available. Recent reports have shown that many of stem cells can exert anti-inflammatory and tissue-regenerating effects. In this study, we investigated the potential cartilage-regenerating and anti-inflammatory effects of human umbilical cord matrix-mesenchymal stem cells (hUCM-MSCs) for the treatment of TMJ-OA. hUCM-MSC lines, isolated from different donors, which showed different activities in vitro. Using a selected cell line, we used different concentrations of hUCM-MSCs to assess therapeutic effects in a rabbit model of monosodium iodoacetate-induced TMJ-OA. Compared with the untreated control group, the potential regenerative result and anti-inflammatory effects of hUCM-MSCs were evident at all the tested concentrations in rabbits with induced TMJ-OA. The median dose of hUCM-MSCs showed the prominent cartilage protective effect and further cartilage regeneration potential. This effect occurred via upregulated expression of growth factors, extracellular matrix markers, and anti-inflammatory cytokines, and reduced expression of pro-inflammatory cytokines. The anti-inflammatory effect of hUCM-MSCs was comparable to that of dexamethasone (DEX). However, only hUCM-MSCs showed potential chondrogenesis effects in this study. In conclusion, our results indicate that hUCM-MSCs may be an effective treatment option for the treatment of TMJ-OA.

Integrated analysis of lncRNA, miRNA and mRNA expression profiling in patients with systemic lupus erythematosus

INTRODUCTION

A great deal of research has reported dysregulated expression of genes in systemic lupus erythematosus (SLE). This study aimed to analyze the lncRNA, miRNA and mRNA expression profile in SLE.

MATERIAL AND METHODS

RNA sequencing (RNA-seq) was used to detect the dysregulated RNAs in SLE. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis were used to explore the function of these differentially expressed RNAs.

RESULTS

2,353 lncRNAs, 827 mRNAs and 24 miRNAs were shown to be differentially expressed. GO analyses demonstrated that differentially expressed RNAs were enriched in a variety of molecular functions and biological processes including ribonucleotide, protein serine/threonine kinase activity function, regulation of B cell differentiation and others. KEGG pathway analyses revealed that differentially expressed mRNAs and lncRNAs were both enriched in FcγR-mediated phagocytosis, glycosaminoglycan biosynthesis-chondroitin sulfate/dermatan sulfate and glyoxylate and dicarboxylate metabolism pathways. The up-regulated miRNAs target genes were mainly enriched in the nuclear factor-κB (NF-κB) signaling pathway. The down-regulated miRNAs target genes were significantly enriched in metabolism of xenobiotics by cytochrome P450, bile secretion and terpenoid backbone biosynthesis pathways.

CONCLUSIONS

The current study reveals a comprehensive expression profile of lncRNAs, miRNAs and mRNAs and implies potential regulatory functions of these RNAs which are involved in the pathogenesis of SLE.

TNF-α-induced exosomal miR-146a mediates mesenchymal stem cell-dependent suppression of urethral stricture

The effective treatment of urethral stricture remains a medical problem. The use of proinflammatory cytokines as stimuli to improve the reparative efficacy of mesenchymal stem cells (MSCs) towards damaged tissues represents an evolving field of investigation. However, the therapeutic benefits of this strategy in the treatment of urethral stricture remain unknown. Here, we enriched exosomes derived from human umbilical cord-derived MSCs pretreated with or without tumor necrosis factor alpha (TNF-α) to evaluate their therapeutic effects in an in vivo model of TGFβ1-induced urethral stricture. Male Sprague-Dawley rats received sham (saline) or TGFβ1 injections to urethral tissues followed by incisions in the urethra. Animals in the TGFβ1 injection (urethral fibrosis) cohort were subsequently injected with vehicle control, or with exosomes derived from MSCs cultured with or without TNF-α. After 4 weeks, rats underwent ultrasound evaluation and, following euthanasia, urethral tissues were harvested for histological and molecular analysis. In vitro, the effects of MSC-derived exosomes on fibroblast secretion of collagen and cytokines were studied by enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), and western blot analysis. Exosomes derived from MSCs pretreated with TNF-α were more effective in suppressing urethral fibrosis and stricture than exosomes from untreated MSCs. We found that miR-146a, an anti-inflammatory miRNA, was strongly upregulated in TNF-α-stimulated MSCs and was selectively packaged into exosomes. Moreover, miR-146a-containing exosomes were taken up by fibroblasts and inhibited fibroblast activation and associated inflammatory responses, a finding that may underlie the therapeutic mechanism for suppression of urethral stricture. Inhibition of miR-146a in TNF-α-treated MSCs partially reduced antifibrotic effects and increased the release of proinflammatory factors of exosomes derived from these cells. Together these findings demonstrate that exosomes derived from TNF-α-treated MSCs are of therapeutic benefit in urethral fibrosis, suggesting that this strategy may have utility as an adjuvant therapy in the treatment of urethral stricture diseases.

Pathogenesis of antiphospholipid syndrome: recent insights and emerging concepts

Introduction: Even though our understanding of the antiphospholipid syndrome (APS) has improved tremendously over the last decades, we are still not in a position to replace symptomatic anticoagulation by pathogenesis based causal treatments. Areas covered: Recent years have provided further insights into pathogenetically relevant mechanisms. These include a differentiation of pathogenic subtypes of antiphospholipid antibodies (aPL), novel mechanisms modulating disease activity, for example, extracellular vesicles and microRNA, and novel players in pathogenesis, for example, neutrophils and neutrophil extracellular traps (NETs). Expert commentary: It is evident that aPL induce a proinflammatory and procoagulant state and recent data suggest that different aPL species activate different signaling pathways which sometimes converge into a common cellular response. This implies that presence of more than one aPL species may disproportionally increase the risk for the major manifestations of APS, that is, thrombosis and fetal loss. Further delineation of the pathogenic mechanisms will hopefully provide clues to causal rather than symptomatic treatments of APS.