Reduced Let-7f in Bone Marrow-Derived Mesenchymal Stem Cells Triggers Treg/Th17 Imbalance in Patients With Systemic Lupus Erythematosus

Low-intensity pulsed ultrasound protects from inflammatory dilated cardiomyopathy through inciting extracellular vesicles

AIMS

CD4+ T cells are activated during inflammatory dilated cardiomyopathy (iDCM) development to induce immunogenic responses that damage the myocardium. Low-intensity pulsed ultrasound (LIPUS), a novel physiotherapy for cardiovascular diseases, has recently been shown to modulate inflammatory responses. However, its efficacy in iDCM remains unknown. Here, we investigated whether LIPUS could improve the severity of iDCM by orchestrating immune responses and explored its therapeutic mechanisms.

METHODS AND RESULTS

In iDCM mice, LIPUS treatment reduced cardiac remodelling and dysfunction. Additionally, CD4+ T-cell inflammatory responses were suppressed. LIPUS increased Treg cells while decreasing Th17 cells. LIPUS mechanically stimulates endothelial cells, resulting in increased secretion of extracellular vesicles (EVs), which are taken up by CD4+ T cells and alter their differentiation and metabolic patterns. Moreover, EVs selectively loaded with microRNA (miR)-99a are responsible for the therapeutic effects of LIPUS. The hnRNPA2B1 translocation from the nucleus to the cytoplasm and binding to caveolin-1 and miR-99a confirmed the upstream mechanism of miR-99a transport. This complex is loaded into EVs and taken up by CD4+ T cells, which further suppress mTOR and TRIB2 expression to modulate cellular differentiation.

CONCLUSION

Our findings revealed that LIPUS uses an EVs-dependent molecular mechanism to protect against iDCM progression. Therefore, LIPUS is a promising new treatment option for iDCM.

Engineered stem cells by emerging biomedical stratagems

Stem cell therapy holds immense potential as a viable treatment for a widespread range of intractable disorders. As the safety of stem cell transplantation having been demonstrated in numerous clinical trials, various kinds of stem cells are currently utilized in medical applications. Despite the achievements, the therapeutic benefits of stem cells for diseases are limited, and the data of clinical researches are unstable. To optimize tthe effectiveness of stem cells, engineering approaches have been developed to enhance their inherent abilities and impart them with new functionalities, paving the way for the next generation of stem cell therapies. This review offers a detailed analysis of engineered stem cells, including their clinical applications and potential for future development. We begin by briefly introducing the recent advances in the production of stem cells (induced pluripotent stem cells (iPSCs), embryonic stem cells (ESCs), mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs)). Furthermore, we present the latest developments of engineered strategies in stem cells, including engineered methods in molecular biology and biomaterial fields, and their application in biomedical research. Finally, we summarize the current obstacles and suggest future prospects for engineered stem cells in clinical translations and biomedical applications.

Cellular microenvironment: a key for tuning mesenchymal stem cell senescence

Mesenchymal stem cells (MSCs) possess the ability to self-renew and differentiate into multiple cell types, making them highly suitable for use as seed cells in tissue engineering. These can be derived from various sources and have been found to play crucial roles in several physiological processes, such as tissue repair, immune regulation, and intercellular communication. However, the limited capacity for cell proliferation and the secretion of senescence-associated secreted phenotypes (SASPs) pose challenges for the clinical application of MSCs. In this review, we provide a comprehensive summary of the senescence characteristics of MSCs and examine the different features of cellular microenvironments studied thus far. Additionally, we discuss the mechanisms by which cellular microenvironments regulate the senescence process of MSCs, offering insights into preserving their functionality and enhancing their effectiveness.

Roquin-1 resolves sepsis-associated acute liver injury by regulating inflammatory profiles via miRNA cargo in extracellular vesicles

Sepsis-associated acute liver injury (SALI) is an independent risk for sepsis-induced death orchestrated by innate and adaptive immune responses. Here, we found that Roquin-1 was decreased during SALI and expressed mainly in monocyte-derived macrophages. Meanwhile, Roquin-1 was correlated with the inflammatory profiles in humans and mice. Mechanically, Roquin-1 in macrophages promoted Ago2-K258-ubiquitination and inhibited Ago2-S387/S828-phosphorylation. Ago2-S387-phosphorylation inhibited Ago2-miRNA's complex location in multivesicular bodies and sorting in macrophages-derived extracellular vesicles (MDEVs), while Ago2-S828-phosphorylation modulated the binding between Ago2 and miRNAs by special miRNAs-motifs. Then, the anti-inflammatory miRNAs in MDEVs decreased TSC22D2 expression directly, upregulated Tregs-differentiation via TSC22D2-STAT3 signaling, and inhibited M1-macrophage-polarization by TSC22D2-AMPKα-mTOR pathway. Furthermore, WT MDEVs in mice alleviated SALI by increasing Tregs ratio and decreasing M1-macrophage frequency synchronously. Our study showed that Roquin-1 in macrophages increased Tregs-differentiation and decreased M1-macrophage-polarization simultaneously via miRNA in MDEVs, suggesting Roquin-1 can be used as a potential tool for SALI treatment and MDEVs engineering.

Modulation of Mesenchymal Stem Cells-Mediated Adaptive Immune Effectors' Repertoire in the Recovery of Systemic Lupus Erythematosus

The breakdown of self-tolerance of the immune response can lead to autoimmune conditions in which chronic inflammation induces tissue damage. Systemic lupus erythematosus (SLE) is a debilitating multisystemic autoimmune disorder with a high prevalence in women of childbearing age; however, SLE incidence, prevalence, and severity are strongly influenced by ethnicity. Although the mystery of autoimmune diseases remains unsolved, disturbance in the proportion and function of B cell subsets has a major role in SLE's pathogenesis. Additionally, colocalizing hyperactive T helper cell subgroups within inflammatory niches are indispensable. Despite significant advances in standard treatments, nonspecific immunosuppression, the risk of serious infections, and resistance to conventional therapies in some cases have raised the urgent need for new treatment strategies. Without the need to suppress the immune system, mesenchymal stem cells (MSCs), as ''smart" immune modulators, are able to control cellular and humoral auto-aggression responses by participating in precursor cell development. In lupus, due to autologous MSCs disorder, the ability of allogenic engrafted MSCs in tissue regeneration and resetting immune homeostasis with the provision of a new immunocyte repertoire has been considered simultaneously. In Brief The bone marrow mesenchymal stem cells (BM-MSCs) lineage plays a critical role in maintaining the hematopoietic stem-cell microstructure and modulating immunocytes. The impairment of BM-MSCs and their niche partially contribute to the pathogenesis of SLE-like diseases. Allogenic MSC transplantation can reconstruct BM microstructure, possibly contributing to the recovery of immunocyte phenotype restoration of immune homeostasis. In terms of future prospects of MSCs, artificially gained by ex vivo isolation and culture adaptation, the wide variety of potential mediators and mechanisms might be linked to the promotion of the immunomodulatory function of MSCs.

Current Progress in Treating Systemic Lupus Erythematosus Using Exosomes/MicroRNAs

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease associated with impaired organ functions that can seriously affect the daily life of patients. Recent SLE therapies frequently elicit adverse reactions and side effects in patients, and clinical heterogeneity is considerable. Mesenchymal stromal cells (MSCs) have anti-inflammatory, tissue repair, and immunomodulatory properties. Their ability to treat autoimmune diseases largely depends on secreted extracellular vesicles, especially exosomes. The effects of exosomes and microRNAs (miRNAs) on SLE have recently attracted interest. This review summarizes the applications of MSCs derived from bone marrow, adipocyte tissue, umbilical cord, synovial membrane, and gingival tissue, as well as exosomes to treating SLE and the key roles of miRNAs. The efficacy of MSCs infusion in SLE patients with impaired autologous MSCs are reviewed, and the potential of exosomes and their contents as drug delivery vectors for treating SLE and other autoimmune diseases in the future are briefly described.

An update on epigenetic regulation in autoimmune diseases

Autoimmune diseases (AIDs) generally manifest as chronic immune disorders characterized by significant heterogeneity and complex symptoms. The discordant incidence of AIDs between monozygotic twins guided people to attach importance to environmental factors. Epigenetics is one of the major ways to be influenced, some of them can even occur years before clinical diagnosis. With the advent of high-throughput omics times, the mysterious veil of epigenetic modification in AIDs has been gradually unraveled, and some progress has been made in utilizing it as indicators of diagnosis and disease activity. For example, the hypomethylated IFI44L promoter in diagnosing systematic lupus erythematosus (SLE). More recently, newly identified noncoding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are also believed to be involved in the etiology of AIDs while the initial factor behind those epigenetic alterations can be diverse from metabolism to microbiota. Update and comprehensive insights into epigenetics in AIDs can help us understand the pathogenesis and further orchestrate it to benefit patients in the future. Therefore, we reviewed the latest epigenetic findings in SLE, rheumatoid arthritis (RA), Type 1 diabetes (T1D), systemic sclerosis (SSc) primarily from cellular levels.

LIPOPOLYSACCHARIDE-PRECONDITIONED MESENCHYMAL STEM CELL TRANSPLANTATION ATTENUATES CRITICAL PERSISTENT INFLAMMATION IMMUNE SUPPRESSION AND CATABOLISM SYNDROME IN MICE

ABSTRACT

Background: Persistent inflammation, immunosuppression, and catabolism syndrome (PIICS) is associated with high mortality and high health care costs, and there is currently no effective target treatment. Mesenchymal stem cells (MSCs) possess multipotent immunomodulatory properties. LPS-preconditioned type 1 MSCs (MSC1s) are potentially beneficial for PIICS treatment because of their proinflammatory, anti-infective, and healing properties. Here, we investigated the therapeutic efficacy and mechanisms of action of MSC1s in PIICS. Methods: We previously optimized a reaggravated PIICS mouse model, which was used in this study. PIICS mice were subjected to cecal ligation and puncture on day 1 and LPS injection on day 11. Subsequently, the mice were treated with or without MSC1s. Animal survival and phenotypes, along with the levels of catabolism, inflammation, and immunosuppression, were evaluated. MSC1s were cocultured with CD8 + T cells in vitro , and inflammatory cytokine levels and CD8 + T-cell function were assessed. Results: MSC1 transplantation alleviated weight loss and muscle wasting, inhibited catabolism and inflammation, and considerably improved the proportion and function of CD8 + T cells in the PIICS mice. After coculture with MSC1s, the expression levels of CD107a and interferon γ increased, whereas the expression level of programmed death 1 decreased significantly in CD8 + T cells. MSC1s also promoted proinflammatory cytokine secretion and reduced the concentration of soluble PD-L1 in vitro . Conclusions: MSC1s can protect mice against critical PIICS, partly by enhancing CD8 + T-cell function. Therefore, MSC1 transplantation is a novel therapeutic candidate for PIICS.

Mesenchymal stem cells exosomal let-7a-5p improve autophagic flux and alleviate liver injury in acute-on-chronic liver failure by promoting nuclear expression of TFEB

Acute-on-chronic liver failure is a distinct clinical syndrome characterized by a dysregulated immune response and extensive hepatocyte death without satisfactory therapies. As a cytoplasmic degradative and quality-control process, autophagy was implicated in maintaining intracellular homeostasis, and decreased hepatic autophagy was found in many liver diseases and contributes to disease pathogenesis. Previously, we identified the therapeutic potential of mesenchymal stem cells (MSCs) in ACLF patients; however, the intrinsic mechanisms are incompletely understood. Herein, we showed that MSCs restored the impaired autophagic flux and alleviated liver injuries in ACLF mice, but these effects were abolished when autophago-lysosomal maturation was inhibited by leupeptin (leu), suggesting that MSCs exerted their hepatoprotective function in a pro-autophagic dependent manner. Moreover, we described a connection between transcription factor EB (TFEB) and autophagic activity in this context, as evidenced by increased nuclei translocation of TFEB elicited by MSCs were capable of promoting liver autophagy. Mechanistically, we confirmed that let-7a-5p enriched in MSCs derived exosomes (MSC-Exo) could activate autophagy by targeting MAP4K3 to reduce TFEB phosphorylation, and MAP4K3 knockdown partially attenuates the effect of anti-let-7a-5p oligonucleotide via decreasing the inflammatory response, in addition, inducing autophagy. Altogether, these findings revealed that the hepatoprotective effect of MSCs may partially profit from its exosomal let-7a-5p mediating autophagy repairment, which may provide new insights for the therapeutic target of ACLF treatment.

MicroRNAs in the regulation of Th17/Treg homeostasis and their potential role in uveitis

Th17 and regulatory T cells (Tregs) play crucial roles in the pathogenesis of autoimmune diseases. Th17/Treg homeostasis is critically involved in maintaining the immune balance. Disturbed Th17/Treg homeostasis contributes to the progression of autoimmune diseases. MicroRNAs (miRNAs) have emerged as a new vital factor in the regulation of disturbed Th17/Treg homeostasis. To better understand the epigenetic mechanisms of miRNAs in regulating Treg/Th17 homeostasis, we included and evaluated 97 articles about autoimmune diseases and found that miRNAs were involved in the regulation of Treg/Th17 homeostasis from several aspects positively or negatively, including Treg differentiation and development, Treg induction, Treg stability, Th17 differentiation, and Treg function. Uveitis is one of the ocular autoimmune diseases, which is also characterized with Th17/Treg imbalance. However, our understanding of the miRNAs in the pathogenesis of uveitis is elusive and not well-studied. In this review, we further summarized miRNAs found to be involved in autoimmune uveitis and their potential role in the regulation of Th17/Treg homeostasis.

Inflammatory MicroRNAs and the Pathophysiology of Endometriosis and Atherosclerosis: Common Pathways and Future Directions Towards Elucidating the Relationship

Emerging data indicates an association between endometriosis and subclinical atherosclerosis, with women with endometriosis at a higher risk for cardiovascular disease later in life. Inflammation is proposed to play a central role in the pathophysiology of both diseases and elevated levels of systemic pro-inflammatory cytokines including macrophage migration inhibitory factor (MIF), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) are well documented. However, a thorough understanding on the mediators and mechanisms which contribute to altered cytokine expression in both diseases remain poorly understood. MicroRNAs (miRNAs) are important post-transcriptional regulators of inflammatory pathways and numerous studies have reported altered circulating levels of miRNAs in both endometriosis and atherosclerosis. Potential contribution of miRNA-mediated inflammatory cascades common to the pathophysiology of both diseases has not been evaluated but could offer insight into common pathways and early manifestation relevant to both diseases which may help understand cause and effect. In this review, we discuss and summarize differentially expressed inflammatory circulating miRNAs in endometriosis subjects, compare this profile to that of circulating levels associated with atherosclerosis when possible, and then discuss mechanistic studies focusing on these miRNAs in relevant cell, tissue, and animal models. We conclude by discussing the potential utility of targeting the relevant miRNAs in the MIF-IL-6-TNF-α pathway as therapeutic options and offer insight into future studies which will help us better understand not only the role of these miRNAs in the pathophysiology of both endometriosis and atherosclerosis but also commonality between both diseases.

Identification of Novel Immune Cell-Relevant Therapeutic Targets and Validation of Roles of TK1 in BMSCs of Systemic Lupus Erythematosus

Objective: Systemic lupus erythematosus (SLE) displays the characteristics of abnormal activity of the immune system, contributing to diverse clinical symptoms. Herein, this study was conducted for discovering novel immune cell-relevant therapeutic targets.

Methods: The abundance of diverse immune cells was estimated in PBMCs of SLE and healthy controls from the GSE50772 dataset with CIBERSORT approach. Immune cell-relevant co-expression modules were screened with WGCNA and relevant characteristic genes were determined with LASSO algorithm. Inflammatory chemokines were measured in serum of twenty SLE patients and twenty controls through ELISA. Bone marrow mesenchymal stem cells (BMSCs) were isolated and TK1 expression was measured in BMSCs through RT-qPCR and western blotting. TK1-overexpressed and TK-1-silenced BMSCs of SLE were conducted and apoptosis and cell cycle were measured with flow cytometry. Apoptosis-, cell cycle- and senescence-relevant proteins were tested with western blotting.

Results: We determined three co-expression modules strongly linked to immune cells. Five characteristic genes (CXCL1, CXCL2, CXCL8, CXCR1 and TK1) were screened and ROC curves proved the excellent diagnostic performance of this LASSO model. Inflammatory chemokines presented widespread up-regulations in serum of Systemic lupus erythematosus patients, demonstrating the activation of inflammatory response. TK1 expression was remarkably elevated in SLE BMSCs than controls. TK1 overexpression enhanced IL-1β expression, apoptosis, cell cycle arrest, and senescent phenotypes of SLE BMSCs and the opposite results were proved in TK1-silenced SLE BMSCs.

Conclusion: Collectively, our findings demonstrate that silencing TK1 alleviates inflammation, growth arrest and senescence in BMSCs of SLE, which highlights TK1 as a promising therapeutic target against SLE.

Mesenchymal Stem Cells-derived Exosomes Ameliorate Lupus by Inducing M2 Macrophage Polarization and Regulatory T Cell Expansion in MRL/lpr Mice

Previous studies have implicated that the transplantation of human umbilical cord mesenchymal stem cells (hUC-MSCs) effectively alleviates systemic lupus erythematosus (SLE) primarily due to immunomodulatory effects. However, little is known about the role of hUC-MSC-derived exosomes in SLE. This study is carried out to investigate the modifying effects of hUC-MSC-exosomes on the differentiation and function of immune cells in SLE. hUC-MSC-derived exosomes were extracted from the cultural supernatant of hUC-MSCs by ultrahigh speed centrifugation. Quantitative real-time polymerase chain reaction, western blot, enzyme-linked immunosorbent assay, and flow cytometry were performed to estimate the effect of hUC-MSC-derived exosomes on macrophage and regulatory T cell (Treg) polarization. In vivo, hUC-MSC-exosomes were injected intravenously into 28-week-old MRL/lpr mice. We had found that exosomes derived from hUC-MSC restrained the proliferation and inflammation of macrophages in vitro. Besides, MSC-exosomes inhibited CD68⁺M1 and HLA-DR⁺M1 but promoted CD206⁺M2 and CD163⁺M2 in vitro. Moreover, MRL/lpr mice administrated by intravenous injection of MSC-exosomes had less infiltration of CD14⁺CD11c⁺M1 cells but more CD14⁺CD163⁺M2 cells as well as Tregs in spleens compared with those in MRL/lpr mice treated by PBS. Additionally, MSC-exosomes could alleviate nephritis, liver and lung injuries of MRL/lpr mice. The survival of lupus mice could be improved after MSC-exosome treatment. This study has suggested that MSC-derived exosomes exert anti-inflammatory and immunomodulatory effects in SLE. MSC-exosomes ameliorate nephritis and other key organ injuries by inducing M2 macrophages and Tregs polarization. As natural nanocarriers, MSC-exosomes may serve as a promising cell-free therapeutic strategy for SLE.Abbreviations: SLE: Systemic lupus erythematosus; hUC-MSCs: Human umbilical cord mesenchymal stem cells; MSCs: Mesenchymal stem cells; qRT-PCR: Quantitative real-time polymerase chain reaction; ELISA: Enzyme-linked immunosorbent assay; Tregs: Regulatory cells; TNF-α: Tumor necrosis factor alfa; IL: Interleukin; COVID-19: Coronavirus disease 2019; pTHP-1: PMA-induced THP-1 macrophages; TEM: Transmission electron microscopy; LPS: Lipopolysaccharide; EVs: Extracellular vesicles; TRAF1: Tumor necrosis factor receptor-associated factor 1; IRAK1: Interferon-α-interleukin-1 receptor-associated kinase 1; NF-κB: Nuclear factor-κB; BLyS: B lymphocyte stimulator; APRIL: A proliferation-inducing ligand.

Stem cell therapy for COVID-19 pneumonia

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus is a highly contagious microorganism, and despite substantial investigation, no progress has been achieved in treating post-COVID complications. However, the virus has made various mutations and has spread around the world. Researchers have tried different treatments to reduce the side effects of the COVID-19 symptoms. One of the most common and effective treatments now used is steroid therapy to reduce the complications of this disease. Long-term steroid therapy for chronic inflammation following COVID-19 is harmful and increases the risk of secondary infection, and effective treatment remains challenging owing to fibrosis and severe inflammation and infection. Sometimes our immune system can severely damage ourselves in disease. In the past, many researchers have conducted various studies on the immunomodulatory properties of stem cells. This property of stem cells led them to modulate the immune system of autoimmune diseases like diabetes, multiple sclerosis, and Parkinson's. Because of their immunomodulatory properties, stem cell-based therapy employing mesenchymal or hematopoietic stem cells may be a viable alternative treatment option in some patients. By priming the immune system and providing cytokines, chemokines, and growth factors, stem cells can be employed to build a long-term regenerative and protective response. This review addresses the latest trends and rapid progress in stem cell treatment for Acute Respiratory Distress Syndrome (ARDS) following COVID-19.

Osteogenic differentiation of mesenchymal stem cells promotes c-Jun-dependent secretion of interleukin 8 and mediates the migration and differentiation of CD4+ T cells

Background

The immune system and the skeletal system have complex interactions in the bone marrow and even in the joints, which has promoted the development of the concept of osteoimmunology. Some evidence has indicated that T cells and B cells contribute to the balance between the resorption and formation of bone. However, there has been little discussion on the regulation of CD4⁺ T lymphocytes by cells involved in bone metabolism. Mesenchymal stem cells (MSCs), which exert core functions related to immunoregulation and osteogenic differentiation, are crucial cells linked to both bone metabolism and the immune system. Previous studies have shown that the immunoregulatory capacity of MSCs changes following differentiation. However, it is still unclear whether the osteogenic differentiation of MSCs affects the migration and differentiation of CD4⁺ T cells.

Methods

MSCs were cultured in growth medium or osteogenic medium for 10 days and then cocultured with CD4+ T cells. CD4+ T cell migration and differentiation were detected by flow cytometry. Further, gene expression levels of specific cytokines were analyzed by quantitative real-time PCR and enzyme-linked immunosorbent assays. A Proteome Profiler Human XL Cytokine Array Kit was used to analyze supernatants collected from MSCs. Alizarin red S staining and Alkaline phosphatase assay were used to detect the osteogenic differentiation of MSCs.

Results

Here, we found that the migration of CD4⁺ T cells was elevated, and the capacity to induce the differentiation of regulatory T (Treg) cells was weakened during MSC osteogenic differentiation, while the differentiation of T helper 1 (Th1), T helper 2 (Th2) and T helper 17 (Th17) cells was not affected. Further studies revealed that interleukin (IL)-8 was significantly upregulated during MSC osteogenic differentiation. Both a neutralizing antibody and IL-8-specific siRNA significantly inhibited the migration of CD4⁺ T cells and promoted the differentiation of Treg cells. Finally, we found that the transcription factor c-Jun was involved in regulating the expression of IL-8 and affected the osteogenic differentiation of MSCs, thereby mediating the migration and differentiation of CD4⁺ T cells.

Conclusion

This study demonstrated that MSC osteogenic differentiation promoted c-Jun-dependent secretion of IL-8 and mediated the migration and differentiation of CD4⁺ T cells. These results provide a further understanding of the crosstalk between bone and the immune system and reveal information about the relationship between osteogenesis and inflammation in the field of osteoimmunology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02735-0.

Hsa_circ_0000437 upregulates and promotes disease progression in rheumatic valvular heart disease

Background

Currently, the diagnosis and outcome of rheumatic valvular heart disease (RVHD) are less than ideal, and there are no accurate biomarkers. Circular RNA (circRNA) might participate in the occurrence and development of RVHD.

Materials and methods

We use circRNA microarray to filter out the target has_circ_0000437. qRT‐PCR was used to measure the expression levels of hsa_circ_0000437 in RVHD plasma samples. We assessed the diagnostic value of hsa_circ_0000437 in RVHD. Cell function in vitro experiment was to explore the effect of has_circ_0000437 on RVHD.

Results

Has_circ_0000437 is highly expressed in RVHD (p < 0.001). has_circ_0000437 has the diagnostic value in RVHD. In RVHD, hsa_circ_0000437 can promote cell proliferation and migration but inhibits its apoptosis. This may be due to the combination of has_circ_0000437 and target miRNA in the cytoplasm that affects the progress of RVHD.

Conclusions

Has_circ_0000437 can promote the process of RVHD and may be a potential for the diagnosis and treatment of RVHD.

Mesenchymal stem cell therapy for COVID-19

The coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) started in December 2019 and affected the whole world in a short time. The course of the disease depends on the person's immune system, physical properties, health status, etc. as it varies according to its characteristics while it is asymptomatic in some people, it causes fatal processes that start with flu-like symptoms such as cough, fever, respiratory distress in some people and progress to acute respiratory distress syndrome (ARDS), severe pneumonia and multi-organ dysfunction, and the basic mechanism underlying these effects known as a cytokine storm. There is no specific effective antiviral drug or vaccine in treatment yet. Supportive/alternative treatment methods are needed as both the desired effect cannot be achieved and undesirable side effects are seen with the current treatments used in the clinic. Mesenchymal stem cells (MSCs) are frequently preferred recently from basic studies to clinical studies and are effective and safe in immune-mediated inflammatory diseases such as Systemic Lupus Erythematosus, Graft-versus-Host disease. MSCs can secrete many types of cytokines through paracrine secretion or directly interact with immune cells leading to immunomodulation. According to the results of the completed studies; it has been stated that the cytokine storm caused by the overstimulation of the immune system decreases and even damage of the cytokine storm on organs decreases, respiratory distress is relieved and contributes to the healing process by repairing damaged tissues. In this review, clinical trials completed/ongoing on MSCs recommended for treating COVID-19, a global problem, are reviewed and the review is prepared to specify the existence of such a route to clinicians.

Immunomodulatory Effect of MSCs and MSCs-Derived Extracellular Vesicles in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a common autoimmune connective tissue disease with unclear etiology and pathogenesis. Mesenchymal stem cell (MSC) and MSC derived extracellular vesicles (EVs) play important roles in regulating innate and adaptive immunity, which are involved in many physiological and pathological processes and contribute to the immune homeostasis in SLE. The effects of MSCs and EVs on SLE have been drawing more and more attention during the past few years. This article reviews the immunomodulatory effects and underlying mechanisms of MSC/MSC-EVs in SLE, which provides novel insight into understanding SLE pathogenesis and guiding the biological therapy.

The relationship of polluted air and drinking water sources with the prevalence of systemic lupus erythematosus: a provincial population-based study

Environmental exposures interact with genetic factors has been thought to influence susceptibility of systemic lupus erythematosus (SLE) development. To evaluate the effects of environmental exposures on SLE, we conducted a population-based cohort study across Jiangsu Province, China, to examine the associations between the living environment including air and water pollution, population density, economic income level, etc. and the prevalence and mortality of hospitalized SLE (h-SLE) patients. A total of 2231 h-SLE patients were retrieved from a longitudinal SLE database collected by the Jiangsu Lupus Collaborative Group from 1999 to 2009. The results showed that: It existed regional differences on the prevalence of h-SLE patients in 96 administrative districts; The distribution of NO₂ air concentration monitored by atmospheric remote sensors showed that three of the ultra-high-prevalence districts were located in the concentrated chemical industry emission area; h-SLE patient prevalence was positively correlated with the excessive levels of nitrogen in drinking water; The positive ratio of pericarditis and proteinuria was positively correlated with the prevalence of h-SLE patients and pollution not only induced a high h-SLE patient prevalence but also a higher mortality rate, which might be attributed to NOx pollution in the air and drinking water. In summary, our data suggested that NOx in air and drinking water may be one of the important predispositions of SLE, especially for patients with renal involvement.

The Th17/IL-17 Axis and Kidney Diseases, With Focus on Lupus Nephritis

Systemic lupus erythematosus (SLE) is a disease characterized by dysregulation and hyperreactivity of the immune response at various levels, including hyperactivation of effector cell subtypes, autoantibodies production, immune complex formation, and deposition in tissues. The consequences of hyperreactivity to the self are systemic and local inflammation and tissue damage in multiple organs. Lupus nephritis (LN) is one of the most worrying manifestations of SLE, and most patients have this involvement at some point in the course of the disease. Among the effector cells involved, the Th17, a subtype of T helper cells (CD4+), has shown significant hyperactivation and participates in kidney damage and many other organs. Th17 cells have IL-17A and IL-17F as main cytokines with receptors expressed in most renal cells, being involved in the activation of many proinflammatory and profibrotic pathways. The Th17/IL-17 axis promotes and maintains repetitive tissue damage and maladaptive repair; leading to fibrosis, loss of organ architecture and function. In the podocytes, the Th17/IL-17 axis effects include changes of the cytoskeleton with increased motility, decreased expression of health proteins, increased oxidative stress, and activation of the inflammasome and caspases resulting in podocytes apoptosis. In renal tubular epithelial cells, the Th17/IL-17 axis promotes the activation of profibrotic pathways such as increased TGF-β expression and epithelial-mesenchymal transition (EMT) with consequent increase of extracellular matrix proteins. In addition, the IL-17 promotes a proinflammatory environment by stimulating the synthesis of inflammatory cytokines by intrinsic renal cells and immune cells, and the synthesis of growth factors and chemokines, which together result in granulopoiesis/myelopoiesis, and further recruitment of immune cells to the kidney. The purpose of this work is to present the prognostic and immunopathologic role of the Th17/IL-17 axis in Kidney diseases, with a special focus on LN, including its exploration as a potential immunotherapeutic target in this complication.

Importance of lymphocyte-stromal cell interactions in autoimmune and inflammatory rheumatic diseases

Interactions between lymphocytes and stromal cells have an important role in immune cell development and responses. During inflammation, stromal cells contribute to inflammation, from induction to chronicity or resolution, through direct cell interactions and through the secretion of pro-inflammatory and anti-inflammatory mediators. Stromal cells are imprinted with tissue-specific phenotypes and contribute to site-specific lymphocyte recruitment. During chronic inflammation, the modified pro-inflammatory microenvironment leads to changes in the stromal cells, which acquire a pathogenic phenotype. At the site of inflammation, infiltrating B cells and T cells interact with stromal cells. These interactions induce a plasma cell-like phenotype in B cells and T cells, associated with secretion of immunoglobulins and inflammatory cytokines, respectively. B cells and T cells also influence the stromal cells, inducing cell proliferation, molecular changes and cytokine production. This positive feedback loop contributes to disease chronicity. This Review describes the importance of these cell interactions in chronic inflammation, with a focus on human disease, using three selected autoimmune and inflammatory diseases: rheumatoid arthritis, psoriatic arthritis (and psoriasis) and systemic lupus erythematosus. Understanding the importance and disease specificity of these interactions could provide new therapeutic options.

RNA Methylation in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with complicated clinical manifestations. Although our understanding of the pathogenesis of SLE has greatly improved, the understanding of the pathogenic mechanisms of SLE is still limited by disease heterogeneity, and targeted therapy is still unavailable. Substantial evidence shows that RNA methylation plays a vital role in the mechanisms of the immune response, prompting speculation that it might also be related to the occurrence and development of SLE. RNA methylation has been a hot topic in the field of epigenetics in recent years. In addition to revealing the modification process, relevant studies have tried to explore the relationship between RNA methylation and the occurrence and development of various diseases. At present, some studies have provided evidence of a relationship between RNA methylation and SLE pathogenesis, but in-depth research and analysis are lacking. This review will start by describing the specific mechanism of RNA methylation and its relationship with the immune response to propose an association between RNA methylation and SLE pathogenesis based on existing studies and then discuss the future direction of this field.

miRNA Landscape in Pathogenesis and Treatment of Vogt-Koyanagi-Harada Disease

miRNAs, one of the members of the noncoding RNA family, are regulators of gene expression in inflammatory and autoimmune diseases. Changes in miRNA pool expression have been associated with differentiation of CD4⁺ T cells toward an inflammatory phenotype and with loss of self-tolerance in autoimmune diseases. Vogt–Koyanagi–Harada (VKH) disease is a chronic multisystemic pathology, affecting the uvea, inner ear, central nervous system, and skin. Several lines of evidence support an autoimmune etiology for VKH, with loss of tolerance against retinal pigmented epithelium-related self-antigens. This deleterious reaction is characterized by exacerbated inflammation, due to an aberrant T_H1 and T_H17 polarization and secretion of their proinflammatory hallmark cytokines interleukin 6 (IL-6), IL-17, interferon γ, and tumor necrosis factor α, and an impaired CD4⁺ CD25^high FoxP3⁺ regulatory T cell function. To restrain inflammation, VKH is pharmacologically treated with corticosteroids and immunosuppressive drugs as first and second line of therapy, respectively. Changes in the expression of miRNAs related to immunoregulatory pathways have been associated with VKH development, whereas some genetic variants of miRNAs have been found to be risk modifiers of VKH. Furthermore, the drugs commonly used in VKH treatment have great influence on miRNA expression, including those miRNAs associated to VKH disease. This relationship between response to therapy and miRNA regulation suggests that these small noncoding molecules might be therapeutic targets for the development of more effective and specific pharmacological therapy for VKH. In this review, we discuss the latest evidence regarding regulation and alteration of miRNA associated with VKH disease and its treatment.

MiRNA, a New Treatment Strategy for Pulmonary Fibrosis

Pulmonary fibrosis (PF) is the most common chronic, progressive interstitial lung disease, mainly occurring in the elderly, with a median survival of 2-4 years after diagnosis. Its high mortality rate attributes to the delay in diagnosis due to its generic symptoms, and more importantly, to the lack of effective treatments. MicroRNAs (miRNAs) are a class of small non-coding RNAs that are involved in many essential cellular processes, including extracellular matrix remodeling, alveolar epithelial cell apoptosis, epithelial-mesenchymal transition, etc. We summarized the dysregulated miRNAs in TGF-β signaling pathway-mediated PF in recent years with dual effects, such as anti-fibrotic let-7 family and pro-fibrotic miR-21 members. Therefore, this review will set out the latest application of miRNAs to provide a new direction for PF treatment.

The Normal Ratio of Th17 and Th1 Post-mesenchymal Stem Cells Coculture with PBMCs of Systemic Lupus Erythematosus Patients

BACKGROUND: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by altered T-cell population homeostasis, including Th1 and Th17 populations. Mesenchymal stem cell (MSC)-induced i-Treg in SLE milieu can suppress Th17 cell populations; however, Th1 cell population status as a response to the Th17 decrease remains unclear. Therefore, improving SLE flare by suppressing Th17 and constantly controlling Th1 under normal level through MSCs administration is crucial. AIM: This study aimed to investigate the role of MSCs in suppressing Th17 cell populations and controlling Th1 to a normal level by in vitro coculturing MSCs with PBMC from SLE patients.. METHODS: This study used a post-test control group design. MSCs were obtained from human umbilical cord blood and characterized according to their surface antigen expression and multilineage differentiation capacities. PBMCs isolated from SLE patients were divided into five groups: Sham, control, and three treatment groups. The treatment groups were treated by coculturing MSCs to PBMCs with a ratio of 1:10, 1:25, and 1:40 for 72 h incubation. Th1 and Th17 cells were analyzed by flow cytometry. RESULTS: This study showed that there was no significance difference of the percentages of Th1 cells on all treatment groups. On the other hand, the percentages of Th17 were significantly decreased on T1 group. Interestingly, there was also significant decrease of Th1-like Th17 cells population on T1 group. CONCLUSIONS: MSCs may suppress Th17 and control Th1 to a normal level by in vitro coculturing MSCs with PBMC from SLE.

Treatment of severe COVID-19 with human umbilical cord mesenchymal stem cells

Background

COVID-19 is a highly infectious respiratory disease. No therapeutics have yet been proven effective for treating severe COVID-19.

Objectives

To determine whether human umbilical cord mesenchymal stem cell infusion may be effective and safe for the treatment of severe COVID-19.

Methods

Patients with severe COVID-19 were randomly divided into 2 groups: the standard treatment group and the standard treatment plus hUC-MSC infusion group. The incidence of progression from severe to critical illness, 28-day mortality, clinical symptom improvement, time to clinical symptom improvement, hematologic indicators including C-reactive protein, lymphocyte number, and interleukin 6, and imaging changes were observed and compared between the two groups.

Measurements and main results

The incidence of progression from severe to critical illness and the 28-day mortality rate were 0 in the hUC-MSC treatment group, while 4 patients in the control group deteriorated to critical condition and received invasive ventilation; 3 of them died, and the 28-day mortality rate was 10.34%. In the hUC-MSC treatment group, the time to clinical improvement was shorter than that in the control group. Clinical symptoms of weakness and fatigue, shortness of breath, and low oxygen saturation obviously improved beginning on the third day of stem cell infusion and reached a significant difference on day 7. CRP and IL-6 levels were significantly lower from day 3 of infusion, the time for the lymphocyte count to return to the normal range was significantly faster, and lung inflammation absorption was significantly shorter on CT imaging in the hUC-MSC group than in the control group.

Conclusions

Intravenous transplantation of hUC-MSCs is a safe and effective method that can be considered a salvage and priority treatment option for severe COVID-19.

Trial registration

Chinese Clinical Trial Registration; ChiCTR2000031494; Registered on 2 April 2020; http://www.medresman.org

Treatment of severe COVID-19 with human umbilical cord mesenchymal stem cells

Background

COVID-19 is a highly infectious respiratory disease. No therapeutics have yet been proven effective for treating severe COVID-19.

Objectives

To determine whether human umbilical cord mesenchymal stem cell infusion may be effective and safe for the treatment of severe COVID-19.

Methods

Patients with severe COVID-19 were randomly divided into 2 groups: the standard treatment group and the standard treatment plus hUC-MSC infusion group. The incidence of progression from severe to critical illness, 28-day mortality, clinical symptom improvement, time to clinical symptom improvement, hematologic indicators including C-reactive protein, lymphocyte number, and interleukin 6, and imaging changes were observed and compared between the two groups.

Measurements and main results

The incidence of progression from severe to critical illness and the 28-day mortality rate were 0 in the hUC-MSC treatment group, while 4 patients in the control group deteriorated to critical condition and received invasive ventilation; 3 of them died, and the 28-day mortality rate was 10.34%. In the hUC-MSC treatment group, the time to clinical improvement was shorter than that in the control group. Clinical symptoms of weakness and fatigue, shortness of breath, and low oxygen saturation obviously improved beginning on the third day of stem cell infusion and reached a significant difference on day 7. CRP and IL-6 levels were significantly lower from day 3 of infusion, the time for the lymphocyte count to return to the normal range was significantly faster, and lung inflammation absorption was significantly shorter on CT imaging in the hUC-MSC group than in the control group.

Conclusions

Intravenous transplantation of hUC-MSCs is a safe and effective method that can be considered a salvage and priority treatment option for severe COVID-19.

Trial registration

Chinese Clinical Trial Registration; ChiCTR2000031494; Registered on 2 April 2020; http://www.medresman.org

Treatment of severe COVID-19 with human umbilical cord mesenchymal stem cells

Background

COVID-19 is a highly infectious respiratory disease. No therapeutics have yet been proven effective for treating severe COVID-19.

Objectives

To determine whether human umbilical cord mesenchymal stem cell infusion may be effective and safe for the treatment of severe COVID-19.

Methods

Patients with severe COVID-19 were randomly divided into 2 groups: the standard treatment group and the standard treatment plus hUC-MSC infusion group. The incidence of progression from severe to critical illness, 28-day mortality, clinical symptom improvement, time to clinical symptom improvement, hematologic indicators including C-reactive protein, lymphocyte number, and interleukin 6, and imaging changes were observed and compared between the two groups.

Measurements and main results

The incidence of progression from severe to critical illness and the 28-day mortality rate were 0 in the hUC-MSC treatment group, while 4 patients in the control group deteriorated to critical condition and received invasive ventilation; 3 of them died, and the 28-day mortality rate was 10.34%. In the hUC-MSC treatment group, the time to clinical improvement was shorter than that in the control group. Clinical symptoms of weakness and fatigue, shortness of breath, and low oxygen saturation obviously improved beginning on the third day of stem cell infusion and reached a significant difference on day 7. CRP and IL-6 levels were significantly lower from day 3 of infusion, the time for the lymphocyte count to return to the normal range was significantly faster, and lung inflammation absorption was significantly shorter on CT imaging in the hUC-MSC group than in the control group.

Conclusions

Intravenous transplantation of hUC-MSCs is a safe and effective method that can be considered a salvage and priority treatment option for severe COVID-19.

Trial registration

Chinese Clinical Trial Registration; ChiCTR2000031494; Registered on 2 April 2020; http://www.medresman.org

Treatment of severe COVID-19 with human umbilical cord mesenchymal stem cells

Background

COVID-19 is a highly infectious respiratory disease. No therapeutics have yet been proven effective for treating severe COVID-19.

Objectives

To determine whether human umbilical cord mesenchymal stem cell infusion may be effective and safe for the treatment of severe COVID-19.

Methods

Patients with severe COVID-19 were randomly divided into 2 groups: the standard treatment group and the standard treatment plus hUC-MSC infusion group. The incidence of progression from severe to critical illness, 28-day mortality, clinical symptom improvement, time to clinical symptom improvement, hematologic indicators including C-reactive protein, lymphocyte number, and interleukin 6, and imaging changes were observed and compared between the two groups.

Measurements and main results

The incidence of progression from severe to critical illness and the 28-day mortality rate were 0 in the hUC-MSC treatment group, while 4 patients in the control group deteriorated to critical condition and received invasive ventilation; 3 of them died, and the 28-day mortality rate was 10.34%. In the hUC-MSC treatment group, the time to clinical improvement was shorter than that in the control group. Clinical symptoms of weakness and fatigue, shortness of breath, and low oxygen saturation obviously improved beginning on the third day of stem cell infusion and reached a significant difference on day 7. CRP and IL-6 levels were significantly lower from day 3 of infusion, the time for the lymphocyte count to return to the normal range was significantly faster, and lung inflammation absorption was significantly shorter on CT imaging in the hUC-MSC group than in the control group.

Conclusions

Intravenous transplantation of hUC-MSCs is a safe and effective method that can be considered a salvage and priority treatment option for severe COVID-19.

Trial registration

Chinese Clinical Trial Registration; ChiCTR2000031494; Registered on 2 April 2020; http://www.medresman.org

Treatment of severe COVID-19 with human umbilical cord mesenchymal stem cells

Background

COVID-19 is a highly infectious respiratory disease. No therapeutics have yet been proven effective for treating severe COVID-19.

Objectives

To determine whether human umbilical cord mesenchymal stem cell infusion may be effective and safe for the treatment of severe COVID-19.

Methods

Patients with severe COVID-19 were randomly divided into 2 groups: the standard treatment group and the standard treatment plus hUC-MSC infusion group. The incidence of progression from severe to critical illness, 28-day mortality, clinical symptom improvement, time to clinical symptom improvement, hematologic indicators including C-reactive protein, lymphocyte number, and interleukin 6, and imaging changes were observed and compared between the two groups.

Measurements and main results

The incidence of progression from severe to critical illness and the 28-day mortality rate were 0 in the hUC-MSC treatment group, while 4 patients in the control group deteriorated to critical condition and received invasive ventilation; 3 of them died, and the 28-day mortality rate was 10.34%. In the hUC-MSC treatment group, the time to clinical improvement was shorter than that in the control group. Clinical symptoms of weakness and fatigue, shortness of breath, and low oxygen saturation obviously improved beginning on the third day of stem cell infusion and reached a significant difference on day 7. CRP and IL-6 levels were significantly lower from day 3 of infusion, the time for the lymphocyte count to return to the normal range was significantly faster, and lung inflammation absorption was significantly shorter on CT imaging in the hUC-MSC group than in the control group.

Conclusions

Intravenous transplantation of hUC-MSCs is a safe and effective method that can be considered a salvage and priority treatment option for severe COVID-19.

Trial registration

Chinese Clinical Trial Registration; ChiCTR2000031494; Registered on 2 April 2020; http://www.medresman.org

Treatment of severe COVID-19 with human umbilical cord mesenchymal stem cells

Background

COVID-19 is a highly infectious respiratory disease. No therapeutics have yet been proven effective for treating severe COVID-19.

Objectives

To determine whether human umbilical cord mesenchymal stem cell infusion may be effective and safe for the treatment of severe COVID-19.

Methods

Patients with severe COVID-19 were randomly divided into 2 groups: the standard treatment group and the standard treatment plus hUC-MSC infusion group. The incidence of progression from severe to critical illness, 28-day mortality, clinical symptom improvement, time to clinical symptom improvement, hematologic indicators including C-reactive protein, lymphocyte number, and interleukin 6, and imaging changes were observed and compared between the two groups.

Measurements and main results

The incidence of progression from severe to critical illness and the 28-day mortality rate were 0 in the hUC-MSC treatment group, while 4 patients in the control group deteriorated to critical condition and received invasive ventilation; 3 of them died, and the 28-day mortality rate was 10.34%. In the hUC-MSC treatment group, the time to clinical improvement was shorter than that in the control group. Clinical symptoms of weakness and fatigue, shortness of breath, and low oxygen saturation obviously improved beginning on the third day of stem cell infusion and reached a significant difference on day 7. CRP and IL-6 levels were significantly lower from day 3 of infusion, the time for the lymphocyte count to return to the normal range was significantly faster, and lung inflammation absorption was significantly shorter on CT imaging in the hUC-MSC group than in the control group.

Conclusions

Intravenous transplantation of hUC-MSCs is a safe and effective method that can be considered a salvage and priority treatment option for severe COVID-19.

Trial registration

Chinese Clinical Trial Registration; ChiCTR2000031494; Registered on 2 April 2020; http://www.medresman.org

Treatment of severe COVID-19 with human umbilical cord mesenchymal stem cells

Background

COVID-19 is a highly infectious respiratory disease. No therapeutics have yet been proven effective for treating severe COVID-19.

Objectives

To determine whether human umbilical cord mesenchymal stem cell infusion may be effective and safe for the treatment of severe COVID-19.

Methods

Patients with severe COVID-19 were randomly divided into 2 groups: the standard treatment group and the standard treatment plus hUC-MSC infusion group. The incidence of progression from severe to critical illness, 28-day mortality, clinical symptom improvement, time to clinical symptom improvement, hematologic indicators including C-reactive protein, lymphocyte number, and interleukin 6, and imaging changes were observed and compared between the two groups.

Measurements and main results

The incidence of progression from severe to critical illness and the 28-day mortality rate were 0 in the hUC-MSC treatment group, while 4 patients in the control group deteriorated to critical condition and received invasive ventilation; 3 of them died, and the 28-day mortality rate was 10.34%. In the hUC-MSC treatment group, the time to clinical improvement was shorter than that in the control group. Clinical symptoms of weakness and fatigue, shortness of breath, and low oxygen saturation obviously improved beginning on the third day of stem cell infusion and reached a significant difference on day 7. CRP and IL-6 levels were significantly lower from day 3 of infusion, the time for the lymphocyte count to return to the normal range was significantly faster, and lung inflammation absorption was significantly shorter on CT imaging in the hUC-MSC group than in the control group.

Conclusions

Intravenous transplantation of hUC-MSCs is a safe and effective method that can be considered a salvage and priority treatment option for severe COVID-19.

Trial registration

Chinese Clinical Trial Registration; ChiCTR2000031494; Registered on 2 April 2020; http://www.medresman.org

Myeloid-derived suppressor cells shift Th17/Treg ratio and promote systemic lupus erythematosus progression through arginase-1/miR-322-5p/TGF-β pathway

Immune cells play important roles in systemic lupus erythematosus (SLE). We previously found that myeloid-derived suppressor cell (MDSC)-derived arginase-1 (Arg-1) promoted Th17 cell differentiation in SLE. In the present study, we performed RNA-chip to identify the microRNA regulation network between MDSCs and Th17 cells. miR-542-5p in humans, as the homologous gene of miR-322-5p in mice was significantly up-regulated in the Th17+MDSC group compared with Th17 cells cultured alone and down-regulated in the Th17+MDSC+Arg-1 inhibitor group compared with the Th17+MDSC group. We further evaluated the miR-322-5p and Th17/Treg balance in mice and found that the proportions of both Th17 cells and Tregs were elevated and that miR-322-5p overexpression activated the transforming growth factor-β pathway. Moreover, although miR-322-5p expression was higher in SLE mice, it decreased after treatment with an Arg-1 inhibitor. The proportion of Th17 cells and Th17/Treg ratio correlated with miR-322-5p levels. In conclusion, MDSC-derived Arg-1 and mmu-miR-322-5p not only promote Th17 cell and Treg differentiation, but also shift the Th17/Treg ratio in SLE. The Arg-1/miR-322-5p axis may serve as a novel treatment target for SLE.

Treatment of severe COVID-19 with human umbilical cord mesenchymal stem cells

Background

COVID-19 is a highly infectious respiratory disease. No therapeutics have yet been proven effective for treating severe COVID-19.

Objectives

To determine whether human umbilical cord mesenchymal stem cell infusion may be effective and safe for the treatment of severe COVID-19.

Methods

Patients with severe COVID-19 were randomly divided into 2 groups: the standard treatment group and the standard treatment plus hUC-MSC infusion group. The incidence of progression from severe to critical illness, 28-day mortality, clinical symptom improvement, time to clinical symptom improvement, hematologic indicators including C-reactive protein, lymphocyte number, and interleukin 6, and imaging changes were observed and compared between the two groups.

Measurements and main results

The incidence of progression from severe to critical illness and the 28-day mortality rate were 0 in the hUC-MSC treatment group, while 4 patients in the control group deteriorated to critical condition and received invasive ventilation; 3 of them died, and the 28-day mortality rate was 10.34%. In the hUC-MSC treatment group, the time to clinical improvement was shorter than that in the control group. Clinical symptoms of weakness and fatigue, shortness of breath, and low oxygen saturation obviously improved beginning on the third day of stem cell infusion and reached a significant difference on day 7. CRP and IL-6 levels were significantly lower from day 3 of infusion, the time for the lymphocyte count to return to the normal range was significantly faster, and lung inflammation absorption was significantly shorter on CT imaging in the hUC-MSC group than in the control group.

Conclusions

Intravenous transplantation of hUC-MSCs is a safe and effective method that can be considered a salvage and priority treatment option for severe COVID-19.

Trial registration

Chinese Clinical Trial Registration; ChiCTR2000031494; Registered on 2 April 2020; http://www.medresman.org

Hydroxychloroquine in rheumatic autoimmune disorders and beyond

Initially used as antimalarial drugs, hydroxychloroquine (HCQ) and, to a lesser extent, chloroquine (CQ) are currently being used to treat several diseases. Due to its cost‐effectiveness, safety and efficacy, HCQ is especially used in rheumatic autoimmune disorders (RADs), such as systemic lupus erythematosus, primary Sjögren's syndrome and rheumatoid arthritis. Despite this widespread use in the clinic, HCQ molecular modes of action are still not completely understood. By influencing several cellular pathways through different mechanisms, CQ and HCQ inhibit multiple endolysosomal functions, including autophagy, as well as endosomal Toll‐like receptor activation and calcium signalling. These effects alter several aspects of the immune system with the synergistic consequence of reducing pro‐inflammatory cytokine production and release, one of the most marked symptoms of RADs. Here, we review the current knowledge on the molecular modes of action of these drugs and the circumstances under which they trigger side effects. This is of particular importance as the therapeutic use of HCQ is expanding beyond the treatment of malaria and RADs.

Mechanisms behind the Immunoregulatory Dialogue between Mesenchymal Stem Cells and Th17 Cells

Mesenchymal stem cells (MSCs) exhibit potent immunoregulatory abilities by interacting with cells of the adaptive and innate immune system. In vitro, MSCs inhibit the differentiation of T cells into T helper 17 (Th17) cells and repress their proliferation. In vivo, the administration of MSCs to treat various experimental inflammatory and autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes, multiple sclerosis, systemic lupus erythematosus, and bowel disease showed promising therapeutic results. These therapeutic properties mediated by MSCs are associated with an attenuated immune response characterized by a reduced frequency of Th17 cells and the generation of regulatory T cells. In this manuscript, we review how MSC and Th17 cells interact, communicate, and exchange information through different ways such as cell-to-cell contact, secretion of soluble factors, and organelle transfer. Moreover, we discuss the consequences of this dynamic dialogue between MSC and Th17 well described by their phenotypic and functional plasticity.

Exploring the Role of Non-Coding RNAs in the Pathophysiology of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic immune-related disorder designated by a lack of tolerance to self-antigens and the over-secretion of autoantibodies against several cellular compartments. Although the exact pathophysiology of SLE has not been clarified yet, this disorder has a strong genetic component based on the results of familial aggregation and twin studies. Variation in the expression of non-coding RNAs has been shown to influence both susceptibility to SLE and the clinical course of this disorder. Several long non-coding RNAs (lncRNAs) such as GAS5, MALAT1 and NEAT1 are dysregulated in SLE patients. Moreover, genetic variants within lncRNAs such as SLEAR and linc00513 have been associated with risk of this disorder. The dysregulation of a number of lncRNAs in the peripheral blood of SLE patients has potentiated them as biomarkers for diagnosis, disease activity and therapeutic response. MicroRNAs (miRNAs) have also been shown to affect apoptosis and the function of immune cells. Taken together, there is a compelling rationale for the better understanding of the involvement of these two classes of non-coding RNAs in the pathogenesis of SLE. Clarification of the function of these transcripts has the potential to elucidate the molecular pathophysiology of SLE and provide new opportunities for the development of targeted therapies for this disorder.