Intravenous transplantation of mesenchymal stromal cells has therapeutic effects in a sepsis mouse model through inhibition of septic natural killer cells

Machine learning reveals the rules governing the efficacy of mesenchymal stromal cells in septic preclinical models

BACKGROUND

Mesenchymal Stromal Cells (MSCs) are the preferred candidates for therapeutics as they possess multi-directional differentiation potential, exhibit potent immunomodulatory activity, are anti-inflammatory, and can function like antimicrobials. These capabilities have therefore encouraged scientists to undertake numerous preclinical as well as a few clinical trials to access the translational potential of MSCs in disease therapeutics. In spite of these efforts, the efficacy of MSCs has not been consistent-as is reflected in the large variation in the values of outcome measures like survival rates. Survival rate is a resultant of complex cascading interactions that not only depends upon upstream experimental factors like dosage, time of infusion, type of transplant, etc.; but is also dictated, post-infusion, by intrinsic host specific attributes like inflammatory microniche including proinflammatory cytokines and alarmins released by the damaged host cells. These complex interdependencies make a researcher's task of designing MSC transfusion experiments challenging.

METHODS

In order to identify the rules and associated attributes that influence the final outcome (survival rates) of MSC transfusion experiments, we decided to apply machine learning techniques on manually curated data collected from available literature. As sepsis is a multi-faceted condition that involves highly dysregulated immune response, inflammatory environment and microbial invasion, sepsis can be an efficient model to verify the therapeutic effects of MSCs. We therefore decided to implement rule-based classification models on data obtained from studies involving interventions of MSCs in sepsis preclinical models.

RESULTS

The rules from the generated graph models indicated that survival rates, post-MSC-infusion, are influenced by factors like source, dosage, time of infusion, pre-Interleukin-6 (IL-6)/ Tumour Necrosis Factor- alpha (TNF-α levels, etc. CONCLUSION: This approach provides important information for optimization of MSCs based treatment strategies that may help the researchers design their experiments.

Immunoregulatory paracrine effect of mesenchymal stem cells and mechanism in the treatment of osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease caused by chronic inflammation that damages articular cartilage. At present, the treatment of OA includes drug therapy to relieve symptoms and joint replacement therapy for advanced OA. However, these palliatives cannot truly block the progression of the disease from the immunological pathogenesis of OA. In recent years, bone marrow mesenchymal stem cell (BMSC) transplantation has shown great potential in tissue engineering repair. In addition, many studies have shown that BMSC paracrine signals play an important role in the treatment of OA through immune regulation and suppressing inflammation. At present, the mechanism of inflammation-induced OA and the use of BMSC transplantation in joint repair have been reviewed, but the mechanism and significance of BMSC paracrine signals in the treatment of OA have not been fully reviewed. Therefore, this article focused on the latest research progress on the paracrine effects of BMSCs in the treatment of OA and the related mechanisms by which BMSCs secrete cytokines to inhibit the inflammatory response, regulate immune balance, and promote cell proliferation and differentiation. In addition, the application potential of BMSC-Exos as a new type of cell-free therapy for OA is described. This review aimed to provide systematic theoretical support for the clinical application of BMSC transplantation in the treatment of OA.

Temporal dynamics of immune-stromal cell interactions in fracture healing

Bone fracture repair is a complex, multi-step process that involves communication between immune and stromal cells to coordinate the repair and regeneration of damaged tissue. In the US, 10% of all bone fractures do not heal properly without intervention, resulting in non-union. Complications from non-union fractures are physically and financially debilitating. We now appreciate the important role that immune cells play in tissue repair, and the necessity of the inflammatory response in initiating healing after skeletal trauma. The temporal dynamics of immune and stromal cell populations have been well characterized across the stages of fracture healing. Recent studies have begun to untangle the intricate mechanisms driving the immune response during normal or atypical, delayed healing. Various in vivo models of fracture healing, including genetic knockouts, as well as in vitro models of the fracture callus, have been implemented to enable experimental manipulation of the heterogeneous cellular environment. The goals of this review are to (1): summarize our current understanding of immune cell involvement in fracture healing (2); describe state-of-the art approaches to study inflammatory cells in fracture healing, including computational and in vitro models; and (3) identify gaps in our knowledge concerning immune-stromal crosstalk during bone healing.

Role of the regulation of mesenchymal stem cells on macrophages in sepsis

Sepsis is a common clinical critical disease with high mortality. The excessive release of cytokines from macrophages is the main cause of out-of-control immune response in sepsis. Mesenchymal stem cells (MSCs) are thought to be useful in adjunctive therapy of sepsis and related diseases, due to their function in immune regulation, anti-inflammatory, antibacterial, and tissue regeneration. Also there have been several successful cases in clinical treatment. Some previous studies have shown that MSCs regulate the function of macrophages through secreting cytokines and extracellular vesicles, or transferring mitochondria directly to target cells, which affects the progress of sepsis. Here, we review the regulation of MSCs on macrophages in sepsis, mainly focus on the regulation ways. We hope that will help to understand the immunological mechanism and also provide some clues for the clinical application of MSCs in the biotherapy of sepsis.

Study of immunomodulatory effects of mesenchymal stem cell-derived exosomes in mouse model of LPS induced systemic inflammation

BACKGROUND

Sepsis is a debilitating systemic inflammation that resulted from infection or injury. Despite many advances in treatment, the resulting mortality rate has remained high due to increasing antibiotic resistance and aging communities. The present study investigated the effects of stem cell-derived exosomes in a mouse model of LPS-induced systemic inflammation.

MATERIALS AND METHODS

To induce sepsis, the LPS model was used. Mice were divided into three groups: normal, patient group (LPS + PBS), and treatment group (LPS + exosome). The treatment group received an intravenous exosome 1 h after induction of the model. Patient and treatment groups were sacrificed at 4, 6, 24, and 48 h after induction of the model, and their tissues were isolated. Blood samples were taken from animal hearts to perform biochemical and immunological tests. The study results were analyzed using Graph Pad Prism software version 9.

RESULTS

Mesenchymal stem cell-derived exosomes decreased serum levels of ALT and AST liver enzymes, decreased neutrophil to lymphocyte ratio (NLR), and improved kidney, liver, and lung tissue damage at 4, 6, and 24 h after model induction. At 24 h, the exosomes were able to reduce serum urea levels. This study revealed decreased levels of inflammatory cytokines such as IL-6, IL-1β, and TNF-α after exosome injection.

CONCLUSION

Our findings suggest that treating mice with stem cell-derived exosomes can ameliorate the destructive effects of inflammation caused by sepsis by reducing inflammatory factors and tissue damage.

Intratracheal administration of umbilical cord-derived mesenchymal stem cells attenuates hyperoxia-induced multi-organ injury via heme oxygenase-1 and JAK/STAT pathways

BACKGROUND

Bronchopulmonary dysplasia (BPD) is not merely a chronic lung disease, but a systemic condition with multiple organs implications predominantly associated with hyperoxia exposure. Despite advances in current management strategies, limited progress has been made in reducing the BPD-related systemic damage. Meanwhile, although the protective effects of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) or their exosomes on hyperoxia-induced lung injury have been explored by many researchers, the underlying mechanism has not been addressed in detail, and few studies have focused on the therapeutic effect on systemic multiple organ injury.

AIM

To investigate whether hUC-MSC intratracheal administration could attenuate hyperoxia-induced lung, heart, and kidney injuries and the underlying regulatory mechanisms.

METHODS

Neonatal rats were exposed to hyperoxia (80% O₂), treated with hUC-MSCs intratracheal (iT) or intraperitoneal (iP) on postnatal day 7, and harvested on postnatal day 21. The tissue sections of the lung, heart, and kidney were analyzed morphometrically. Protein contents of the bronchoalveolar lavage fluid (BALF), myeloperoxidase (MPO) expression, and malondialdehyde (MDA) levels were examined. Pulmonary inflammatory cytokines were measured via enzyme-linked immunosorbent assay. A comparative transcriptomic analysis of differentially expressed genes (DEGs) in lung tissue was conducted via RNA-sequencing. Subsequently, we performed reverse transcription-quantitative polymerase chain reaction and western blot analysis to explore the expression of target mRNA and proteins related to inflammatory and oxidative responses.

RESULTS

iT hUC-MSCs administration improved pulmonary alveolarization and angiogenesis (P < 0.01, P < 0.01, P < 0.001, and P < 0.05 for mean linear intercept, septal counts, vascular medial thickness index, and microvessel density respectively). Meanwhile, treatment with hUC-MSCs iT ameliorated right ventricular hypertrophy (for Fulton’s index, P < 0.01), and relieved reduced nephrogenic zone width (P < 0.01) and glomerular diameter (P < 0.001) in kidneys. Among the beneficial effects, a reduction of BALF protein, MPO, and MDA was observed in hUC-MSCs groups (P < 0.01, P < 0.001, and P < 0.05 respectively). Increased pro-inflammatory cytokines tumor necrosis factor-alpha, interleukin (IL)-1β, and IL-6 expression observed in the hyperoxia group were significantly attenuated by hUC-MSCs administration (P < 0.01, P < 0.001, and P < 0.05 respectively). In addition, we observed an increase in anti-inflammatory cytokine IL-10 expression in rats that received hUC-MSCs iT compared with rats reared in hyperoxia (P < 0.05). Transcriptomic analysis showed that the DEGs in lung tissues induced by hyperoxia were enriched in pathways related to inflammatory responses, epithelial cell proliferation, and vasculature development. hUC-MSCs administration blunted these hyperoxia-induced dysregulated genes and resulted in a shift in the gene expression pattern toward the normoxia group. hUC-MSCs increased heme oxygenase-1 (HO-1), JAK2, and STAT3 expression, and their phosphorylation in the lung, heart, and kidney (P < 0.05). Remarkably, no significant difference was observed between the iT and iP administration.

CONCLUSION

iT hUC-MSCs administration ameliorates hyperoxia-induced lung, heart, and kidney injuries by activating HO-1 expression and JAK/STAT signaling. The therapeutic benefits of local iT and iP administration are equivalent.

Mesenchymal stem cells and natural killer cells interaction mechanisms and potential clinical applications

Natural killer cells (NK cells) are innate immune cells that are activated to fight tumor cells and virus-infected cells. NK cells also play an important role in the graft versus leukemia response. However, they can over-develop inflammatory reactions by secreting inflammatory cytokines and increasing Th1 differentiation, eventually leading to tissue damage. Today, researchers have attributed some autoimmune diseases and GVHD to NK cells. On the other hand, it has been shown that mesenchymal stem cells (MSCs) can modulate the activity of NK cells, while some researchers have shown that NK cells can cause MSCs to lysis. Therefore, we considered it is necessary to investigate the effect of these two cells and their signaling pathway in contact with each other, also their clinical applications.

Effect of Bone Marrow Mesenchymal Stromal Cell Therapies in Rodent Models of Sepsis: A Meta-Analysis

Background

Multiple preclinical studies have demonstrated that bone‐marrow derived mesenchymal stromal (stem) cells [MSC(M)] positively influence the severity of sepsis symptoms and mortality in rodent models. However, this remains an inconclusive finding.

Objective

To review the effect of naïve MSC(M) in rodent models of sepsis.

Methods

The PubMed, EMBASE, and Web of Science databases were searched up to August 31, 2021. Inclusion criteria according to PICOS criteria were as follows: (1) population: rodents; (2) intervention: unmodified MSC(M); (3) comparison: not specified; (4) primary outcome: the effects of MSC(M) cell therapy on the mortality of rodent models of sepsis and endotoxemia; (5) study: experimental studies. Multiple prespecified subgroup and meta-regression analysis were conducted. Following quality assessment, random effects models were used for this meta-analysis.The inverse variance method of the fixed effects model was used to calculate the pooled odds ratios (ORs) and their 95% confidence intervals (CIs).

Results

twenty-four animal studies met the inclusion criteria. Our results revealed an overall OR difference between animals treated with naïve MSC(M) and controls for mortality rate was 0.34(95% confidence interval: 0.27-0.44; P < 0.0001). Significant heterogeneity among studies was observed.

Conclusions

The findings of this meta-analysis suggest that naïve MSC(M) therapy decreased mortality in rodent models of sepsis. Additionally, we identified several key knowledge gaps, including the lack of large animal studies and uncertainty regarding the optimal dose of MSC(M) transplantation in sepsis. Before MSC(M) treatment can advance to clinical trials, these knowledge gaps must be addressed.

Review of the potential of mesenchymal stem cells for the treatment of infectious diseases

The therapeutic value of mesenchymal stem cells (MSCs) for the treatment of infectious diseases and the repair of disease-induced tissue damage has been explored extensively. MSCs inhibit inflammation, reduce pathogen load and tissue damage encountered during infectious diseases through the secretion of antimicrobial factors for pathogen clearance and they phagocytose certain bacteria themselves. MSCs dampen tissue damage during infection by downregulating the levels of pro-inflammatory cytokines, and inhibiting the excessive recruitment of neutrophils and proliferation of T cells at the site of injury. MSCs aid in the regeneration of damaged tissue by differentiating into the damaged cell types or by releasing paracrine factors that direct tissue regeneration, differentiation, and wound healing. In this review, we discuss in detail the various mechanisms by which MSCs help combat pathogens, tissue damage associated with infectious diseases, and challenges in utilizing MSCs for therapy.

Sepsis and Septic Shock; Current Treatment Dilemma and Role of Stem Cell Therapy in Pediatrics

Context: Sepsis’s primary therapy consists of antibiotics therapy, supportive therapies, and source control of infection. The failure rate of this approach is about 20 - 40%. The widespread use of antibiotics has caused multiple drug resistance in primary etiological agents of sepsis in community-acquired and healthcare-associated infections. In the absence of new antibiotic options, alternative treatment modalities seem necessary. Evidence Acquisition: Herein, we have reviewed and discussed current problems with sepsis management and stem cell therapy in sepsis, preclinical, experimental studies, and early-phase clinical trials using stem cells to treat sepsis. In the preparation of the paper, PubMed, Web of Science Core Collection (Clarivate), Scopus, and the web address (www.clinicaltrials.gov) were searched by the keywords (sepsis and cell therapy, septic shock, and cell therapy). Results: After the inclusion of criteria, we reviewed 301 original articles. Few articles were found for phase II and phase III clinical trials. Eighty-three articles were included in the current review article. Besides problems with infection source control, the host immune response to the infection enumerated for primary underlying pathophysiologic dysregulation of sepsis and complicated the treatment. Mesenchymal stem cells (MSCs) therapy offers a promising treatment option for sepsis. Indeed, immunomodulatory properties, antimicrobial activity, the capacity of protection against organ failure, enhance the resolution of tissue injury, tissue repair, and restoration after sepsis confer MSCs with a significant advantage to treat the immune and inflammatory dysfunctions associated with severe sepsis and septic shock. Conclusions: It seems that MSCs therapy exhibits an appropriate safety index. Future trials should focus on strengthening study quality, reporting MSCs’ therapeutic effects and adverse events. Although early clinical trials seem promising and have beneficial effects, we need more controlled clinical studies, especially in phases II and III.

Immunomodulatory and Therapeutic Effects of Mesenchymal Stem Cells on Organ Dysfunction in Sepsis

ABSTRACT

Sepsis is a life-threatening disorder that is caused by a dysregulated inflammatory response during an infection. The disease mostly affects pregnant women, newborns, and patients in intensive care units. Sepsis treatment is a significant part of a country's health budgets. Delay in the therapy causes irreversible failure of various organs due to the lack of blood supply and reduction of oxygen in the tissues and eventually increased mortality. The involvement of four or five organs by sepsis has been attributed to an increased risk of death to over 90%. Although antibiotics are at the first line of sepsis treatment, they do not possess enough potency to control the disease and prevent subsequent organ failure. The immunomodulatory, anti-inflammatory, anti-apoptotic, and anti-microbial properties of mesenchymal stem cells (MSCs) have been reported in various studies. Therefore, the application of MSCs has been considered a potentially promising therapeutic strategy. In preclinical studies, the administration of MSCs has been associated with reduced bacterial load and decreased levels of pro-inflammatory factors as well as the improved function of the different vital organs, including heart, kidney, liver, and lungs. The current study provides a brief review of sepsis and its pathophysiology, and then highlights recent findings in the therapeutic effects of MSCs and MSC-derived secretome in improving sepsis-induced organ dysfunction. Besides, eligible sepsis candidates for MSC-therapy and the latest clinical findings in these areas have been reviewed.

Immunomodulatory and Tissue-preserving Effects of Human Dental Follicle Stem Cells in a Rat Cecal Ligation and Perforation Sepsis Model

BACKGROUND

Mesenchymal stem cells may be used for the treatment of sepsis. Dental follicle stem cells (DFSCs) are easily accessible but have not been studied in vivo or in clinical trials in sepsis models.

AIM OF THE STUDY

We aim to elucidate DFSC effects on host immunological functions in a rat cecal ligation and perforation (CLP) sepsis model.

METHODS

Adult male rats were categorized into group 1 (sham procedure SP), group 2 (SP + 1 × 10⁶ DFSCs administered 0 h after SP), group 3 (CLP + saline), group 4 (CLP + 1 × 10⁶ DFSCs administered 0 h after CLP), and group 5 (CLP + 1 × 10⁶ DFSCs administered 4 h after CLP). Green fluorescent protein-labeled cells were used for imaging. Histopathological examination of ileal tissues was performed.

RESULTS

A significant increase in the percentage of CD4+/CD25+/Foxp3+ Treg cells in groups 4 and 5 occurred compared with that in group 3. No significant changes in CD3+/CD4+ helper T-cells and CD3+/CD8+ cytotoxic T-cells were observed. Treatment with DFSCs at 4 h significantly decreased the level of TNF-α compared with that in group 3. No significant changes in IL-10 levels and lymphocyte proliferation suppression were observed. During histopathological examination, no high scoring (Chiu scores: 3 or 4) rats were observed in the curative treatment group (group 5).

CONCLUSIONS

Treatment with DFSC after 4 h of sepsis induction downregulates tissue inflammatory responses by decreasing TNF-α levels and increasing Treg cell ratio. This also has a protective effect on intestinal tissues during sepsis.

Mesenchymal stem cells alter the frequency and cytokine profile of natural killer cells in abortion-prone mice

Natural killer cells, which play a pivotal role in the establishment and maintenance of normal pregnancy, are the most abundant leukocytes at the fetomaternal interface that their subsets frequencies and cytokine profile are influential factors in the preservation of the decidual tolerogenic microenvironment. Any imbalance in NK cells' frequency and functions could be associated with pregnancy failure. Mesenchymal stem cells (MSCs) are shown to have immunomodulatory effects on NK cells and their cytokine profile. The purpose of this study is to evaluate the impact of MSCs therapy on the cytokine profiles and subpopulations of NK cells in a murine model of recurrent pregnancy loss. Adipose-derived MSCs were injected intraperitoneally to the abortion-prone mice on Day 4.5 of gestation. The abortion rate was determined after MSCs administration and the frequency and cytokine profiles of the different subsets of NK cells were determined using the flow cytometry. Our results showed that, in abortion-prone mice, the frequency of CD49b⁺ NK cells was significantly higher than normal pregnant mice that decreased after therapy. We also demonstrated that MSCs downregulated the production of IFN-γ and upregulated IL-4 and IL-10 production by uNK cells. These findings indicate that MSCs can decrease the infiltration of CD49b⁺ NK cells to the fetomaternal interface and modulate the cytokine profile of NK cells from inflammatory to tolerogenic profile and thereby improve the tolerogenic microenvironment at the fetomaternal interface in benefit of pregnancy maintenance.

Mesenchymal stromal cell-based therapies for acute kidney injury: progress in the last decade

A little over 10 years ago, the therapeutic potential of mesenchymal stromal cells (MSCs) for the treatment of acute kidney injury (AKI) was becoming widely recognized. Since then, there has been further intensive study of this topic with a clear translational intent. Over the past decade, many more animal model studies have strengthened the evidence that systemically or locally delivered MSCs ameliorate renal injury in sterile and sepsis-associated AKI. Some of these preclinical studies have also provided a range of compelling new insights into the in vivo fate and mechanisms of action of MSCs in the setting of AKI and other inflammatory conditions. Coupled with increased knowledge of the functional roles of resident and infiltrating immune cell mediators in determining the severity and outcome of AKI, the progress made in the past decade would appear to have significantly strengthened the translational pathway for MSC-based therapies. In contrast, however, the extent of the clinical experience with MSC administration in human subjects with AKI or sepsis-associated AKI has been limited to a small number of early-phase clinical trials, which appear to demonstrate safety but have not thus far delivered a strong signal of efficacy. In this review, we summarize the most significant new developments in the field of MSC-based therapies as they relate to AKI and reflect on the key gaps in knowledge and technology that remain to be addressed for the true clinical potential of MSCs and, perhaps, other emerging cellular therapies to be realized.

Bone marrow vs Wharton's jelly mesenchymal stem cells in experimental sepsis: a comparative study

BACKGROUND

The use of mesenchymal stem cells (MSCs) is being extensively studied in clinical trials in the setting of various diseases including diabetes, stroke, and progressive multiple sclerosis. The unique immunomodulatory properties of MSCs also point them as a possible therapeutic tool during sepsis and septic shock, a devastating syndrome associated with 30-35% mortality. However, MSCs are not equal regarding their activity, depending on their tissue origin. Here, we aimed at comparing the in vivo properties of MSCs according to their tissue source (bone marrow (BM) versus Wharton's jelly (WJ)) in a murine cecal ligation and puncture (CLP) model of sepsis that mimics a human peritonitis. We hypothesized that MSC properties may vary depending on their tissue source in the setting of sepsis.

METHODS

CLP, adult, male, C57BL/6 mice were randomized in 3 groups receiving respectively 0.25 × 106 BM-MSCs, 0.25 × 106 WJ-MSCs, or 150 μL phosphate-buffered saline (PBS) intravenously 24 h after the CLP procedure.

RESULTS

We observed that both types of MSCs regulated leukocyte trafficking and reduced organ dysfunction, while only WJ-MSCs were able to improve bacterial clearance and survival.

CONCLUSION

This study highlights the importance to determine the most appropriate source of MSCs for a given therapeutic indication and suggests a better profile for WJ-MSCs during sepsis.

Mesenchymal stromal cell-derived extracellular vesicles: regenerative and immunomodulatory effects and potential applications in sepsis

Mesenchymal stromal (stem) cells (MSCs) have multipotent differentiation capacity and exist in nearly all forms of post-natal organs and tissues. The immunosuppressive and anti-inflammatory properties of MSCs have made them an ideal candidate in the treatment of diseases, such as sepsis, in which inflammation plays a critical role. One of the key mechanisms of MSCs appears to derive from their paracrine activity. Recent studies have demonstrated that MSC-derived extracellular vesicles (MSC-EVs) are at least partially responsible for the paracrine effect. MSC-EVs transfer molecules (such as proteins/peptides, mRNA, microRNA and lipids) with immunoregulatory properties to recipient cells. MSC-EVs have been shown to mimic MSCs in alleviating sepsis and may serve as an alternative to whole cell therapy. Compared with MSCs, MSC-EVs may offer specific advantages due to lower immunogenicity and higher safety profile. The first two sections of the review discuss the preclinical and clinical findings of MSCs in sepsis. Next, we review the characteristics of EVs and MSC-EVs. Then, we summarize the mechanisms of MSC-EVs, including tissue regeneration and immunomodulation. Finally, our review presents the evidences that MSC-EVs are effective in treating models of sepsis. In conclusion, MSC-EVs may have the potential to become a novel therapeutic strategy for sepsis.

The Immunomodulatory Effects of Mesenchymal Stem Cell Polarization within the Tumor Microenvironment Niche

Mesenchymal stem cells (MSCs) represent a promising tool for cell therapy, particularly for their antitumor effects. This cell population can be isolated from multiple tissue sources and also display an innate ability to home to areas of inflammation, such as tumors. Upon entry into the tumor microenvironment niche, MSCs promote or inhibit tumor progression by various mechanisms, largely through the release of soluble factors. These factors can be immunomodulatory by activating or inhibiting both the adaptive and innate immune responses. The mechanisms by which MSCs modulate the immune response are not well understood. Because of this, the relationship between MSCs and immune cells within the tumor microenvironment niche continues to be an active area of research in order to help explain the apparent contradictory findings currently available in the literature. The ongoing research aims to enhance the potential of MSCs in future therapeutic applications.

Concise Review: Mesenchymal Stromal/Stem Cells: A New Treatment for Sepsis and Septic Shock?

Sepsis and septic shock are the leading cause of admission and mortality in non-coronary intensive care units. Currently, however, no specific treatments are available for this syndrome. Due to the failure of conventional treatments in recent years, research is focusing on innovative therapeutic agents, including cell therapy. One particular type of cell, mesenchymal stromal/stem cells (MSCs), has raised hopes for the treatment of sepsis. Indeed, their immunomodulatory properties, antimicrobial activity and capacity of protection against organ failure confer MSCs with a major advantage to treat the immune and inflammatory dysfunctions associated with sepsis and septic shock. After a brief description of the pathophysiology of sepsis and septic shock, the latest advances in the use of MSCs to treat sepsis will be presented. Stem Cells 2017;35:2331-2339.

Mesenchymal Stem Cells in Sepsis and Associated Organ Dysfunction: A Promising Future or Blind Alley?

Sepsis, newly defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection, is the most common cause of death in ICUs and one of the principal causes of death worldwide. Although substantial progress has been made in the understanding of fundamental mechanisms of sepsis, translation of these advances into clinically effective therapies has been disappointing. Given the extreme complexity of sepsis pathogenesis, the paradigm “one disease, one drug” is obviously flawed and combinations of multiple targets that involve early immunomodulation and cellular protection are needed. In this context, the immune-reprogramming properties of cell-based therapy using mesenchymal stem cells (MSC) represent an emerging therapeutic strategy in sepsis and associated organ dysfunction. This article provides an update of the current knowledge regarding MSC in preclinical models of sepsis and sepsis-induced acute kidney injury. Recommendations for further translational research in this field are discussed.