Mesenchymal stem cells decrease lung inflammation during sepsis, acting through inhibition of the MAPK pathway

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.

Curcumin-primed olfactory mucosa-derived mesenchymal stem cells mitigate cerebral ischemia/reperfusion injury-induced neuronal PANoptosis by modulating microglial polarization

BACKGROUND

Cerebral ischemia-reperfusion (I/R) injury often leads to neuronal death through persistent neuroinflammatory responses. Recent research has unveiled a unique inflammatory programmed cell death mode known as PANoptosis. However, direct evidence for PANoptosis in ischemic stroke-induced neuronal death has not been established. Although it is widely thought that modulating the balance of microglial phenotypic polarization in cerebral I/R could mitigate neuroinflammation-mediated neuronal death, it remains unknown whether microglial polarization influences PANoptotic neuronal death triggered by cerebral I/R. Our prior study demonstrated that curcumin (CUR) preconditioning could boost the neuroprotective properties of olfactory mucosa-derived mesenchymal stem cells (OM-MSCs) in intracerebral hemorrhage. Yet, the potential neuroprotective capacity of curcumin-pretreated OM-MSCs (CUR-OM-MSCs) on reducing PANoptotic neuronal death during cerebral I/R injury through modulating microglial polarization is uncertain.

METHODS

To mimic cerebral I/R injury, We established in vivo models of reversible middle cerebral artery occlusion (MCAO) in C57BL/6 mice and in vitro models of oxygen-glucose deprivation/reoxygenation (OGD/R) in HT22 neurons and BV2 microglia.

RESULTS

Our findings indicated that cerebral I/R injury caused PANoptotic neuronal death and triggered microglia to adopt an M1 (pro-inflammatory) phenotype both in vivo and in vitro. Curcumin pretreatment enhanced the proliferation and anti-inflammatory capacity of OM-MSCs. The CUR-OM-MSCs group experienced a more pronounced reduction in PANoptotic neuronal death and a better recovery of neurological function than the OM-MSCs group. Bioinformatic analysis revealed that microRNA-423-5p (miRNA-423-5p) expression was obviously upregulated in CUR-OM-MSCs compared to OM-MSCs. CUR-OM-MSCs treatment induced the switch to an M2 (anti-inflammatory) phenotype in microglia by releasing miRNA-423-5p, which targeted nucleotide-binding oligomerization domain 2 (NOD2), an upstream regulator of NF-kappaB (NF-κB) and Mitogen-Activated Protein Kinase (MAPK) signaling pathways, to attenuate PANoptotic neuronal death resulting from cerebral I/R.

CONCLUSION

This results provide the first demonstration of the existence of PANoptotic neuronal death in cerebral I/R conditions. Curcumin preconditioning enhanced the ameliorating effect of OM-MSCs on neuroinflammation mediated by microglia polarization via upregulating the abundance of miRNA-423-5p. This intervention effectively alleviates PANoptotic neuronal death resulting from cerebral I/R. The combination of curcumin with OM-MSCs holds promise as a potentially efficacious treatment for cerebral ischemic stroke in the future.

Stem cell-based therapy for fibrotic diseases: mechanisms and pathways

Fibrosis is a pathological process, that could result in permanent scarring and impairment of the physiological function of the affected organ; this condition which is categorized under the term organ failure could affect various organs in different situations. The involvement of the major organs, such as the lungs, liver, kidney, heart, and skin, is associated with a high rate of morbidity and mortality across the world. Fibrotic disorders encompass a broad range of complications and could be traced to various illnesses and impairments; these could range from simple skin scars with beauty issues to severe rheumatologic or inflammatory disorders such as systemic sclerosis as well as idiopathic pulmonary fibrosis. Besides, the overactivation of immune responses during any inflammatory condition causing tissue damage could contribute to the pathogenic fibrotic events accompanying the healing response; for instance, the inflammation resulting from tissue engraftment could cause the formation of fibrotic scars in the grafted tissue, even in cases where the immune system deals with hard to clear infections, fibrotic scars could follow and cause severe adverse effects. A good example of such a complication is post-Covid19 lung fibrosis which could impair the life of the affected individuals with extensive lung involvement. However, effective therapies that halt or slow down the progression of fibrosis are missing in the current clinical settings. Considering the immunomodulatory and regenerative potential of distinct stem cell types, their application as an anti-fibrotic agent, capable of attenuating tissue fibrosis has been investigated by many researchers. Although the majority of the studies addressing the anti-fibrotic effects of stem cells indicated their potent capabilities, the underlying mechanisms, and pathways by which these cells could impact fibrotic processes remain poorly understood. Here, we first, review the properties of various stem cell types utilized so far as anti-fibrotic treatments and discuss the challenges and limitations associated with their applications in clinical settings; then, we will summarize the general and organ-specific mechanisms and pathways contributing to tissue fibrosis; finally, we will describe the mechanisms and pathways considered to be employed by distinct stem cell types for exerting anti-fibrotic events.

Fangji Fuling Decoction Alleviates Sepsis by Blocking MAPK14/FOXO3A Signaling Pathway

OBJECTIVE

To examine the therapeutic effect of Fangji Fuling Decoction (FFD) on sepsis through network pharmacological analysis combined with in vitro and in vivo experiments.

METHODS

A sepsis mouse model was constructed through intraperitoneal injection of 20 mg/kg lipopolysaccharide (LPS). RAW264.7 cells were stimulated by 250 ng/mL LPS to establish an in vitro cell model. Network pharmacology analysis identified the key molecular pathway associated with FFD in sepsis. Through ectopic expression and depletion experiments, the effect of FFD on multiple organ damage in septic mice, as well as on cell proliferation and apoptosis in relation to the mitogen-activated protein kinase 14/Forkhead Box O 3A (MAPK14/FOXO3A) signaling pathway, was analyzed.

RESULTS

FFD reduced organ damage and inflammation in LPS-induced septic mice and suppressed LPS-induced macrophage apoptosis and inflammation in vitro (P<0.05). Network pharmacology analysis showed that FFD could regulate the MAPK14/FOXO signaling pathway during sepsis. As confirmed by in vitro cell experiments, FFD inhibited the MAPK14 signaling pathway or FOXO3A expression to relieve LPS-induced macrophage apoptosis and inflammation (P<0.05). Furthermore, FFD inhibited the MAPK14/FOXO3A signaling pathway to inhibit LPS-induced macrophage apoptosis in the lung tissue of septic mice (P<0.05).

CONCLUSION

FFD could ameliorate the LPS-induced inflammatory response in septic mice by inhibiting the MAPK14/FOXO3A signaling pathway.

Clinical practice of sepsis-induced immunosuppression: Current immunotherapy and future options

Sepsis is a potentially fatal condition characterized by the failure of one or more organs due to a disordered host response to infection. The development of sepsis is closely linked to immune dysfunction. As a result, immunotherapy has gained traction as a promising approach to sepsis treatment, as it holds the potential to reverse immunosuppression and restore immune balance, thereby improving the prognosis of septic patients. However, due to the highly heterogeneous nature of sepsis, it is crucial to carefully select the appropriate patient population for immunotherapy. This review summarizes the current and evolved treatments for sepsis-induced immunosuppression to enhance clinicians' understanding and practical application of immunotherapy in the management of sepsis.

Preclinical assessments of safety and tumorigenicity of very high doses of allogeneic human umbilical cord mesenchymal stem cells

Human umbilical cord-mesenchymal stem cells (hUC-MSCs) have been widely investigated as a new therapeutic agent to treat injuries and inflammatory-mediated and autoimmune diseases. Previous studies have reported on the safety of low-dose infusion of hUC-MSCs, but information on the cell behaviour at higher doses and frequency of injection of the cells remains uncertain. The aim of the present study was to demonstrate the safety and efficacy of hUC-MSCs by Cytopeutics® (Selangor, Malaysia) from low to an extremely high dose in different monitoring periods in healthy BALB/c mice as well as assessing the tumorigenicity of the cells in B-NDG SCID immunocompromised mice. Umbilical cord from two healthy human newborns was obtained and the isolation of the hUC-MSCs was performed based on previous established method. Assessment of the cells at different doses of single or multiple administrations was performed on healthy BALB/c mice in dose range finding, sub-acute (7 d and 28 d) and sub-chronic periods (90 d). Tumorigenicity potential of Cytopeutics® hUC-MSCs was also evaluated on B-NDG immunocompromised mice for 26 wk. Single or multiple administrations of Cytopeutics® hUC-MSCs up to 40 × 106 cells per kilogramme of body weight (kg BW) were found to have no adverse effect in terms of clinical symptoms, haematology and other laboratory parameters, and histology examination in healthy BALB/c mice. hUC-MSCs were also found to reduce pro-inflammatory cytokines (IL-6 and TNF-α) in a dose-dependent manner. No sign of tumor formation was observed in B-NDG mice in the 26-wk tumorigenicity assessment. Single or multiple administration of allogenic Cytopeutics® hUC-MSCs was safe even at very high doses, is non-tumorigenic and did not cause adverse effects in mice throughout the evaluation periods. In addition, Cytopeutics® hUC-MSCs exhibited immunomodulatory effect in a dose-dependent manner.

Improvement of renal functions in mice with septic acute kidney injury using secretome of mesenchymal stem cells

Background

A potentially fatal complication of sepsis is septic acute kidney injury. Stem cell therapy is a potential new method of treating sepsis and has been applied to treat some human diseases.

Objectives

This study investigated the effects of secretome-MSCs on NGAL, CRP, NF-κB, and MMP-9 proteins, and histopathology in mice with septic AKI.

Methods

A post-test-only group design was conducted in 30 Balb/C male mice, which were randomly assigned to five groups: the control group was intraperitoneally injected with 0.5 ml of 0.9 % NaCl, the septic AKI, and the treatment groups (T1, T2, and T3) were intraperitoneally injected with 0.5 ml of 0.9 % NaCl and 0.3 mg/kg BW LPS single dose for three days. Three-day treatments of 150, 300, and 600 µl secretome-MSCs were administered intraperitoneally into the treatment groups. Furthermore, kidney and blood samples were collected for biochemical and histopathological analyses.

Results

The T1, T2, and T3 groups had lower expression of NF-κB and MMP-9 and significantly lower CRP and NGAL levels than that of septic AKI group. T1 (1.21 ± 0.19), T2 (0.75 ± 0.22), and T3 (0.38 ± 0.14) groups demonstrated lower average scores for inflammation, necrosis, hemorrhage, and degeneration compared to septic AKI group (2.17 ± 0.13).

Conclusions

Administration of 600 µl/20 g BW secretome-MSCs suppresses NF-κB and MMP-9 expression and reduces CRP and NGAL levels. Meanwhile, the 150 and 300 µl/20 g BW doses also indicated a greater improvement in renal tissue damage of mice with septic AKI.

Insulin-like growth factor-1 expression levels in pro-inflammatory response in calves with neonatal systemic inflammatory response syndrome

The objective of this study was to investigate the mRNA expression of insulin-like growth factor-1 (IGF-1), pro-inflammatory cytokines (IL-1β, IL-6, IL-18, and TNF-α), serum immunoglobulin profiles (IgG and IgM), and lipid peroxidation status (MDA) in relation to pro-inflammatory cytokines. A case-controlled, prospective, and observational investigation was completed on 85 calves. Total RNA was isolated from whole blood samples of both the SIRS and healthy calves, followed by reverse transcription into cDNA. The resulting cDNAs were mixed with iTaq Universal SYBR Green Supermix and primers specific to the relevant genes using the Rotor-Gene Q instrument. After the reaction was completed, gene expressions were normalised against β-actin using the 2-ΔΔCT method. The mRNA levels of pro-inflammatory cytokines namely (IL-1β [SIRS: 2.15 ± 0.55, Control: 1.13 ± 0.62; P = 0.001], IL-6 [SIRS: 2.82 ± 0.52, Control: 0.91 ± 0.11; P < 0.001], IL-18 [SIRS: 1.92 ± 0.41, Control: 0.99 ± 0.13; P < 0.001], and TNF-α [SIRS: 2.59 ± 0.28, Control: 0.93 ± 0.09; P < 0.001]) and IGF-1 (SIRS: 3.55 ± 0.55, Control: 0.91 ± 0.15; P < 0.001) were up-regulated in calves with SIRS, while serum IgG (SIRS: 4.16 ± 0.26, Control: 1.73 ± 0.17; P < 0.001), IgM (SIRS: 1.55 ± 0.11, Control: 1.09 ± 0.13; P < 0.001), and MDA levels (SIRS: 41.12 ± 3.48, Control: 3.76 ± 0.81; P < 0.001) increased significantly in these calves. Furthermore, significant (P < 0.01) positive correlations were found in calves with SIRS in relation to the expression levels of IL-1β, IL-6, IL-18, TNF-α, IGF-1, serum immunoglobulins, and MDA levels. These results suggest that IGF-1 could be a valuable pro-inflammatory marker, considering its high positive correlation with the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-18, and TNF-α) and markers (MDA, IgG, and IgM) in calves with SIRS.

Rosavin inhibits neutrophil extracellular traps formation to ameliorate sepsis-induced lung injury by regulating the MAPK pathway

BACKGROUND

Sepsis is a systemic organ dysfunction caused by infection, and the most affected organ is the lungs. Rosavin, a traditional Tibetan medicine, exerts an impressive anti--inflammatory effect. However, its effects on sepsis-related lung damage have not been investigated.

PURPOSE

This study aimed to investigate the effects of Rosavin on cecal ligation and puncture (CLP)-induced lung injury.

METHODS

The sepsis mouse model was established by CLP, and the mice were pretreated with Rosavin to explore whether it contributed to the alleviation of lung injury. Hematoxylin-eosin (H&E) stain and lung injury score were used to assess the severity of lung injury. The bronchoalveolar lavage fluid (BALF) inflammatory mediators (tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6], IL-1β, and IL-17A) were detected by ELISA. The number of neutrophils in BALF was detected using flow cytometry. The immunofluorescence assay was used to detect histone and myeloperoxidase (MPO) in lung tissues. Then, the western blot was performed to detect the expression of mitogen-activated protein kinase (MAPK) pathways (extracellular regulated kinase [ERK], p-ERK, p38, p-p38, Jun N-terminal kinase 1/2 [JNK1/2], and p-JNK1/2) in lung tissues.

RESULTS

We found that Rosavin significantly attenuated sepsis-induced lung injury. Specifically, Rosavin significantly inhibited inflammation response by decreasing the secretion of inflammatory mediators. The level of neutrophil extracellular traps (NETs) and MPO activity in CLP were decreased after administration with Rosavin. Moreover, the western blot showed that Rosavin could suppress NETs formation by inhibiting the MAPK/ERK/p38/JNK signaling pathway.

CONCLUSION

These findings demonstrated that Rosavin inhibited NETs formation to attenuate sepsis-induced lung injury, and the inhibitory effect may be exerted via deregulation of the MAPK pathways.

Down-Regulation of CXCR4 in Mesenchymal Stem Cells by Septic Serum

Background

Sepsis is one of the main concerns of health and one of the leading causes of death in hospitals. It is essential to manage sepsis in hospitalized patients. In recent years, cell therapy has been considered as a new approach to treat sepsis. This study evaluated the effect of CXCR4 as one of the main proteins involved in the homing of mesenchymal stem cells in the sepsis serum in mice model.

Methods

Mouse sepsis model was induced by injection of E.coli and biochemical analyses was done to confirm the organ failure. Mesenchymal stem cells (MSCs) derived from bone marrow were separated into sepsis and control groups. In the sepsis serum group, MSCs were treated with sepsis serum at two time points: 24 and 48 h. Quantitative RT-PCR and flow cytometry were performed to determine the mRNA expression of CXCR4 in sepsis serum group compared to control group. Also, a migration assay was done to assess the migration capacity of bone marrow MSCs during inflammation and treatment in sepsis.

Results

Our result showed that treatment with sepsis serum can control migration by decrease in CXCR4 level (P ≤ 0.05) compared to control group. Moreover it was also reported that sepsis serum decreased mRNA expression of CXCR4 in MScs.

Conclusions

In our study, MSCs treated with septic serum were no longer able to migrate . Probably many variables such as source, dose, injection time, and injection route of MSCs after sepsis induction in the animal models are key factors for successful cell therapy.

Impact of Microenvironmental Changes during Degeneration on Intervertebral Disc Progenitor Cells: A Comparison with Mesenchymal Stem Cells

Intervertebral disc (IVD) degeneration occurs with natural ageing and is linked to low back pain, a common disease. As an avascular tissue, the microenvironment inside the IVD is harsh. During degeneration, the condition becomes even more compromised, presenting a significant challenge to the survival and function of the resident cells, as well as to any regeneration attempts using cell implantation. Mesenchymal stem cells (MSCs) have been proposed as a candidate stem cell tool for IVD regeneration. Recently, endogenous IVD progenitor cells have been identified inside the IVD, highlighting their potential for self-repair. IVD progenitor cells have properties similar to MSCs, with minor differences in potency and surface marker expression. Currently, it is unclear how IVD progenitor cells react to microenvironmental factors and in what ways they possibly behave differently to MSCs. Here, we first summarized the microenvironmental factors presented in the IVD and their changes during degeneration. Then, we analyzed the available studies on the responses of IVD progenitor cells and MSCs to these factors, and made comparisons between these two types of cells, when possible, in an attempt to achieve a clear understanding of the characteristics of IVD progenitor cells when compared to MSCs; as well as, to provide possible clues to cell fate after implantation, which may facilitate future manipulation and design of IVD regeneration studies.

Investigating the Immunomodulatory Potential of Dental Pulp Stem Cell Cultured on Decellularized Bladder Hydrogel towards Macrophage Response In Vitro

Mesenchymal stem cells (MSCs) possess immunomodulatory properties and capacity for endogenous regeneration. Therefore, MSC therapy is a promising treatment strategy for COVID-19. However, the cells cannot stay in the lung long enough to exert their function. The extracellular matrix from porcine bladders (B-ECM) has been shown not only to regulate cellular activities but also to possess immunoregulatory characteristics. Therefore, it can be hypothesized that B-ECM hydrogel could be an excellent scaffold for MSCs to grow and could anchor MSCs long enough in the lung so that they can exhibit their immunomodulatory functions. In this study, ECM degradation products and a co-culture system of MSCs and macrophages were developed to study the immunomodulatory properties of ECM and MSCs under septic conditions. The results showed that B-ECM degradation products could decrease pro-inflammatory and increase anti-inflammatory cytokines from macrophages. In an in vivo mimicking co-culture system, MSCs cultured on B-ECM hydrogel exhibited immunomodulatory properties at both gene and protein levels. Both B-ECM degradation products and MSC conditioned medium supported the wound healing of alveolar epithelial cells. The results from the study could offer a basis for investigation of immunomodulation by ECM and MSCs before conducting in vivo experiments, which could later be applied in regenerative medicine.

Bone marrow mesenchymal stem cells enhance angiogenesis and promote fat retention in fat grafting via polarized macrophages

Background

Fat grafting is one of the most common soft tissue filling methods in plastic surgery. Bone marrow mesenchymal stem cell (BM-MSC) transplantation is an effective method for improving graft retention. However, the role of BM-MSCs in fat transplantation is not completely clear.

Methods

Human fat particles, together with BM-MSCs or PBS as a control, were subcutaneously transplanted into the backs of nude mice. Samples were taken on days 14, 30 and 90 post-grafting to calculate the fat graft retention rate, and tissue staining was evaluated. Furthermore, macrophages were treated with BM-MSC conditioned medium (BM-MSC-CM) to identify the beneficial component secreted by these stem cells.

Results

In this study, we found that BM-MSCs improved retention by enhancing angiogenesis in fat grafting. Further analysis revealed that BM-MSCs could significantly inhibit the expression of the proinflammatory M1 macrophage markers interleukin (IL)-1β, tumor necrosis factor-α (TNF-α) and IL-6 in the early stages of fat grafting and promote the expression of the anti-inflammatory M2 macrophage markers Arg1, IL-10 and VEGF. Furthermore, our results showed that IL-10 secreted by BM-MSCs induced M2 macrophage polarization in vitro.

Conclusions

BM-MSC transplantation can improve the fat retention rate and promote angiogenesis, which may be related to M2 macrophages. These results help elucidate the role of BM-MSCs in fat grafting.

Elevated lncRNA-UCA1 upregulates EZH2 to promote inflammatory response in sepsis-induced pneumonia via inhibiting HOXA1

Sepsis is characterized by a dysregulated inflammatory response. We aimed to explore the role of the long non-coding RNA urothelial carcinoma associated 1 (lncRNA UCA1)/enhancer of zeste homolog 2 (EZH2)/homeobox A1 (HOXA1) axis in sepsis-induced pneumonia. The sepsis rat models and RLE-6TN cellular sepsis-induced pneumonia models were established using ligation and puncture (CLP) and lipopolysaccharide (LPS). The expression of UCA1, EZH2 and HOXA1 in rat lung tissues and RLE-6TN cells was detected. Then, the CLP rats were respectively treated with UCA1 up-regulation or UCA1 silencing, EZH2 overexpression to measure their roles in the pathology, apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in CLP rat lung tissues. The cells were subjected to same treatment to examine the effects of UCA1, EZH2 and HOXA1 on viability, apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in LPS-induced RLE-6TN cells. The interactions among UCA1, EZH2 and HOXA1 were identified. UCA1 and EZH2 were upregulated while HOXA1 was downregulated in CLP rat lung tissues and LPS-induced RLE-6TN cells. Elevated UCA1 or increased EZH2 aggravated pathology and promoted apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in CLP rat lung tissues, and inhibited viability while facilitated apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in LPS-induced RLE-6TN cells. UCA1 inhibition exerted contrary effects. Silenced EZH2 reversed the effects of UCA1 elevation on sepsis-induced pneumonia. UCA1 targeted EZH2 that interacted with HOXA1. UCA1 overexpression upregulates EZH2 to repress HOXA1 expression, thus aggravating the progression of sepsis-induced pneumonia, which could be alleviated by EZH2 inhibition.

Proteomic and phosphorylated proteomic landscape of injured lung in juvenile septic rats with therapeutic application of umbilical cord mesenchymal stem cells

Acute lung injury (ALI) is the most common complication of sepsis. Intravenous injection of HUMSCs can regulate the level of circulating endothelial cytokines and alleviate lung injury in juvenile septic rats. In this study, we performed proteomic and phosphorylated proteomic analysis of lung tissue of juvenile septic rats after Human Umbilical Cord Mesenchymal Stem Cells (HUMSCs) intervention for the first time, and screened the potential proteins and pathways of HUMSCs for therapeutic effect. The 4D proteome quantitative technique was used to quantitatively analyze the lung tissues of septic rats 24 hours (3 biological samples) and 24 hours after HUMSCs intervention (3 biological samples). A total of 213 proteins were identified as differentially expressed proteins, and 971 phosphorylation sites changed significantly. Based on the public database, we analyzed the functional enrichment of these proteins and phosphorylated proteins. In addition, Tenascin-C may be the key differential protein and ECM receptor interaction pathway may be the main signal pathway by using various algorithms to analyze the protein-protein interaction network. Phosphorylation analysis showed that tight junction pathway was closely related to immune inflammatory reaction, and EGFR interacted most, which may be the key differential phosphorylated protein. Finally, 123 conserved motifs of serine phosphorylation site (pS) and 17 conserved motifs of threonine (pT) phosphorylation sites were identified by motif analysis of phosphorylation sites. Results from proteomics and phosphorylated proteomics, the potential new therapeutic targets of HUMSCs in alleviating lung injury in juvenile septic rats were revealed.

Melatonin Alleviates Silica Nanoparticle-Induced Lung Inflammation via Thioredoxin-Interacting Protein Downregulation

Silica dioxide nanoparticles (SiONPs) have been increasingly used in various industries; however, this has raised concerns regarding their potential toxicity. SiONPs are also a major component in the Asian sand dust that causes pulmonary diseases among the general public. Melatonin exerts some inhibitory effects against lung inflammation. In this study, we explored the therapeutic properties of melatonin against lung inflammation using an SiONPs-induced lung inflammation murine model and SiONPs-stimulated H292 cells, human airway epithelial cell line, by focusing on the involvement of thioredoxin-interacting protein (TXNIP) in the modulation of the MAPKs/AP-1 axis. We induced an inflammatory response by exposing mouse lungs and the H292 cells to SiONPs and confirmed the anti-inflammatory effect of melatonin. Melatonin inhibited the expression of various inflammatory mediators, including TNF-α, IL-6, and IL-1β, in SiONPs-exposed mice and SiONPs-stimulated H292 cells; this inhibition contributed to a decline in inflammatory cell accumulation in the lung tissues. Furthermore, melatonin treatment decreased the expression of MAPKs and AP-1 by downregulating TXNIP, eventually decreasing the production of SiONPs-induced inflammatory mediators. Overall, these data suggest that melatonin reduces SiONPs-induced lung inflammation by downregulating the TXNIP/MAPKs/AP-1 signalling pathway, thereby supporting the use of melatonin as an effective approach to control SiONPs-induced lung inflammation.

Current Status of Cell-Based Therapies for COVID-19: Evidence From Mesenchymal Stromal Cells in Sepsis and ARDS

The severe respiratory consequences of the coronavirus disease 2019 (COVID-19) pandemic have prompted the urgent need for novel therapies. Cell-based therapies, primarily using mesenchymal stromal cells (MSCs), have demonstrated safety and potential efficacy in the treatment of critical illness, particularly sepsis and acute respiratory distress syndrome (ARDS). However, there are limited preclinical data for MSCs in COVID-19. Recent studies have shown that MSCs could decrease inflammation, improve lung permeability, enhance microbe and alveolar fluid clearance, and promote lung epithelial and endothelial repair. In addition, MSC-based therapy has shown promising effects in preclinical studies and phase 1 clinical trials in sepsis and ARDS. Here, we review recent advances related to MSC-based therapy in the context of sepsis and ARDS and evaluate the potential value of MSCs as a therapeutic strategy for COVID-19.

Curcumin preconditioning enhances the efficacy of adipose-derived mesenchymal stem cells to accelerate healing of burn wounds

Background

Following recent findings from our group that curcumin preconditioning augments the therapeutic efficacy of adipose-derived stem cells in the healing of diabetic wounds in rats, we aimed to investigate the regenerative effects of curcumin preconditioned adipose-derived mesenchymal stem cells (ASCs) for better recovery of acid inflicted burns in this study.

Methods

ASCs were preconditioned with 5 μM curcumin for 24 hours and assessed for proliferation, migration, paracrine release potential and gene expression comparative to naïve ASCs. Subsequently, the healing capacity of curcumin preconditioned ASCs (Cur-ASCs) versus naïve ASCs was examined using acidic wounds in rats. For this, acid inflicted burns of 20 mm in diameter were made on the back of male Wistar rats. Then, 2 × 10⁶ cells of Cur-ASCs and naïve ASCs were intradermally injected in the wound periphery (n = 6) for comparison with an untreated saline control. Post-transplantation, wounds were macroscopically analysed and photographed to evaluate the percentage of wound closure and period of re-epithelization. Healed wound biopsies were excised and used for histological evaluation and expression analysis of wound healing markers at molecular level by quantitative PCR and western blotting.

Results

We found that Cur-ASCs exhibited greater proliferation, migration and paracrine potential in vitro. Further, Cur-ASCs showed more effective recovery than naïve ASCs as exhibited by gross morphology, faster wound closure and earlier re-epithelialization. Masson’s trichrome and hematoxylin and eosin staining demonstrated the improved architecture of the healing burns, as evidenced by reduced infiltration of inflammatory cells, compact collagen and marked granulation in Cur-ASC treated rats. Corroborating these findings, molecular assessment showed significantly reduced expressions of pro-inflammatory factors (interleukin-1 beta, interleukin-6, tumor necrosis factor alpha) a with striking upsurge of an oxidative marker (superoxide dismutase 1), pro-angiogenic factors (vascular endothelial growth factor, hepatocyte growth factor, hypoxia-inducible factor-1 alpha) and collagen markers (transforming growth factor beta 1, fibroblast growth factor-2, collagen type 1 alpha 1), verifying that Cur-ASCs modulate the regulation of pro-inflammatory and healing markers at burn sites.

Conclusions

Treatment with Cur-ASCs resulted in faster re-epithelization of acid inflicted burns compared to the treatment with naïve ASCs. Based on observed findings, we suggest the transplantation of Cur-ASCs is a valuable therapy for the potent clinical management of acidic burns.

Bone marrow-mesenchymal stem cell-derived exosomal microRNA-141 targets PTEN and activates β-catenin to alleviate myocardial injury in septic mice

BACKGROUND

Mesenchymal stem cells (MSCs) and their derived exosomes have shown potentials in the control of myocardial dysfunction. This study aimed to reveal the function of bone marrow (BM)-MSC-derived exosomes in sepsis-induced myocardial injury and the molecular mechanism.

METHODS

BM-MSC-derived exosomes were obtained and identified. A mouse model with sepsis was induced by cecalligation puncture (CLP) and treated with exosomes. The myocardial function of mice, the production of creatine kinase MB (CK-MB) and lactate dehydrogenase (LDH) in serum, the phosphorylation of a key myocardial contractility-related protein phospholamban (PLB), and the pathological changes in the myocardial tissues were examined. A microRNA (miRNA) microarray analysis was performed to examine the candidate miRNAs carried by the exosomes. Rescue experiments were conducted to validate the involvement of miR-141.

RESULTS

CLP treatment led to sepsis and notably reduced the myocardial function in mice. Further treatment of BM-MSC-derived exosomes alleviated the CLP-induced myocardial impairment, production of CK-MB and LDH, and inflammatory infiltration and cell apoptosis in mouse myocardial tissues, and restored the PLB phosphorylation. miR-141 was the most upregulated miRNA in the myocardial tissues after exosome treatment. Downregulation of miR-141 blocked the myocardium-protective functions of the exosomes. miR-141 was found to bind to and suppress PTEN expression, which further enhanced the activity of β-catenin.

CONCLUSION

This study suggested that BM-MSC derived exosomes ameliorates myocardial injury in septic mice through conveying miRNA-141 and regulating the PTEN/β-catenin axis, and exosomes may serve as promising tools for the management of myocardial injury induced by sepsis or other factors.

Mesenchymal stem cells-derived extracellular vesicles carrying microRNA-17 inhibits macrophage apoptosis in lipopolysaccharide-induced sepsis

OBJECTIVE

Sepsis, as a disease affecting the microcirculation and tissue perfusion, results in tissue hypoxia and multiple organ dysfunctions. Bone mesenchymal stem cell (BMSC)-derived extracellular vesicles (EVs) have been demonstrated to transfer trivial molecules (proteins/peptides, mRNA, microRNA and lipids) to alleviate sepsis. We sought to define the function of microRNA (miR)-17 carried in BMSC-EVs in sepsis.

METHODS

The purity of the extracted BMSCs was identified and confirmed by detection of the surface markers by flow cytometry, followed by osteoblastic, adipogenic, and chondrocyte differentiation experiments. Subsequently, EVs were collected from the medium of BMSCs. The uptake of PKH-67-labeled BMSC-EVs or EVs carrying cy3-miR-17 by RAW264.7 cells was observed under laser confocal microscopy. Furthermore, a series of gain- and loss-of-function approaches were conducted to test the effects of LPS, miR-17 and BRD4 on the inflammatory factors (IL-1β, IL-6 and TNF-α), number of M1 macrophages and M2 macrophages, inflammatory-related signal pathway factors (EZH2, c-MYC and TRAIL), macrophage proliferation, and apoptosis in sepsis. The survival rates were measured in vivo.

RESULTS

BMSC-EVs was internalized by the RAW264.7 cells. BDR4 was verified as a target of miR-17, while the expression pattern of miR-17 was upregulated in BMSC-EVs. MiR-17 carried by BMSC-EVs inhibited LPS-induced inflammation and apoptosis of RAW264.7 cells, but improved the viability of RAW264.7 cells. Next, in vitro experiments supported that miR-17 inhibited LPS-induced inflammation in RAW264.7 cells through BRD4/EZH2/TRAIL axis. BRD4 overexpression reversed the effects of miR-17. Moreover, the therapeutic function of BMSC-EVs carried miR-17 was verified by in vivo experiments.

CONCLUSIONS

MiR-17 derived from BMSCs-EVs regulates BRD4-mediated EZH2/TRAIL axis to essentially inhibit LPS-induced macrophages inflammation.

Effect of mesenchymal stem cells on cytochrome-c release and inflammation in colon cancer induced by 1,2-dimethylhydrazine in Wistar albino rats

Colon cancer is one of the most common causes of deaths by cancer worldwide. Stem cells have immunosuppressive properties that promote tumor targeting and circumvent obstacles currently in gene therapy. Bone marrow stem cells are believed to have anticancer potential. The transplantation of mesenchymal stem cells (MSCs), a type of bone marrow stem cells, has been considered a potential therapy for patients with solid tumors due to their capability to enhance the immune response; MSC transplantation has received renewed interest in recent years. The present study aimed to evaluate the antiapoptotic effects of the MSCs on 1,2-dimethylhydrazine (DMH)-induced inflammation in the rat model of colorectal cancer. The rats were randomly allocated into four groups: control, treated with MSCs, induced by DMH, and induced by DMH and treated with MSCs. The MSCs were intra-rectally injected, and DMH was subcutaneously injected at 20 mg/kg body weight once a week for 15 weeks. The administration of MSCs into rats starting from day 0 of the DMH injection was found to enhance the histopathological picture. The MSC treatment resulted in fewer inflammatory cells than in the DMH group. Therefore, our findings suggest that BMCs have antitumor effects by modulating the cellular redox status and down-regulating the pro-inflammatory genes. Thus, BMCs may provide therapeutic value for colon cancer treatment.

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.

IL-21 treatment recovers follicular helper T cells and neutralizing antibody production in respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infections in children under 1 year. RSV vaccines are currently unavailable, and children suffering from multiple reinfections by the same viral strain fail to develop protective responses. Although RSV-specific antibodies can be detected upon infection, these have limited neutralizing capacity. Follicular helper T (Tfh) cells are specialized in providing signals to B cells and help the production and affinity maturation of antibodies, mainly via interleukin (IL) 21 secretion. In this study, we evaluated whether RSV could inhibit Tfh responses. We observed that Tfh cells fail to upregulate IL-21 production upon RSV infection. In the lungs, RSV infection downregulated the expression of IL-21/interleukin-21 receptor (IL-21R) in Tfh cells and upregulated programmed death-ligand 1 (PD-L1) expression in dendritic cells (DCs) and B cells. PD-L1 blockade during infection recovered IL-21R expression in Tfh cells and increased the secretion of IL-21 in a DC-dependent manner. IL-21 treatment decreased RSV viral load and lung inflammation, inducing the formation of tertiary lymphoid organs in the lung. It also decreased regulatory follicular T cells, and increased Tfh cells, B cells, antibody avidity and neutralization capacity, leading to an overall improved anti-RSV humoral response in infected mice. Passive immunization with purified immunoglobulin G from IL-21-treated RSV-infected mice protected against RSV infection. Our results unveil a pathway by which RSV affects Tfh cells by increasing PD-L1 expression on antigen-presenting cells, highlighting the importance of an IL-21-PD-L1 axis for the generation of protective responses to RSV infection.

A phase Ib/IIa, randomised, double-blind, multicentre trial to assess the safety and efficacy of expanded Cx611 allogeneic adipose-derived stem cells (eASCs) for the treatment of patients with community-acquired bacterial pneumonia admitted to the intensive care unit

Background

Community-acquired bacterial pneumonia (CABP) can lead to sepsis and is associated with high mortality rates in patients presenting with shock and/or respiratory failure and who require mechanical ventilation and admission to intensive care units, thus reflecting the limited effectiveness of current therapy. Preclinical studies support the efficacy of expanded allogeneic adipose-derived mesenchymal stem cells (eASCs) in the treatment of sepsis. In this study, we aim to test the safety, tolerability and efficacy of eASCs as adjunctive therapy in patients with severe CABP (sCABP).

Methods

In addition to standard of care according to local guidelines, we will administer eASCs (Cx611) or placebo intravenously as adjunctive therapy to patients with sCABP. Enrolment is planned for approximately 180 patients who will be randomised to treatment groups in a 1:1 ratio according to a pre-defined randomization list. An equal number of patients is planned for allocation to each group. Cx611 will be administered on Day 1 and on Day 3 at a dose of 160 million cells (2 million cells / mL, total volume 80 mL) through a 20–30 min (240 mL/hr) intravenous (IV) central line infusion after dilution with Ringer Lactate solution. Placebo (Ringer Lactate) will also be administered through a 20–30 min (240 mL/hr) IV central line infusion at the same quantity (total volume of 80 mL) and following the same schedule as the active treatment. The study was initiated in January 2017 and approved by competent authorities and ethics committees in Belgium, Spain, Lithuania, Italy, Norway and France; monitoring will be performed at regular intervals. Funding is from the European Union’s Horizon 2020 Research and Innovation Program.

Discussion

SEPCELL is the first trial to assess the effects of eASCs in sCABP. The data generated will advance understanding of the mode of action of Cx611 and will provide evidence on the safety, tolerability and efficacy of Cx611 in patients with sCABP. These data will be critical for the design of future confirmatory clinical investigations and will assist in defining endpoints, key biomarkers of interest and sample size determination.

Trial registration

NCT03158727, retrospectively registered on 9 May 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-020-01324-2.

Umbilical Cord-Derived CD362+ Mesenchymal Stromal Cells Attenuate Polymicrobial Sepsis Induced by Caecal Ligation and Puncture

Mesenchymal stromal cells (MSCs) have a multimodal, immunomodulatory mechanism of action and are now in clinical trials for single organ and systemic sepsis. However, a number of practicalities around source, homogeneity and therapeutic window remain to be determined. Here, we utilised conditioned medium from CD362⁺-sorted umbilical cord-human MSCs (UC-hMSCs) for a series of in vitro anti-inflammatory assays and the cryopreserved MSCs themselves in a severe (Series 1) or moderate (Series 2+3) caecal ligation and puncture (CLP) rodent model. Surviving animals were assessed at 48 h post injury induction. MSCs improved human lung, colonic and kidney epithelial cell survival following cytokine activation. In severe systemic sepsis, MSCs administered at 30 min enhanced survival (Series 1), and reduced organ bacterial load. In moderate systemic sepsis (Series 2), MSCs were ineffective when delivered immediately or 24 h later. Of importance, MSCs delivered 4 h post induction of moderate sepsis (Series 3) were effective, improving serum lactate, enhancing bacterial clearance from tissues, reducing pro-inflammatory cytokine concentrations and increasing antimicrobial peptides in serum. While demonstrating benefit and immunomodulation in systemic sepsis, therapeutic efficacy may be limited to a specific point of disease onset, and repeat dosing, MSC enhancement or other contingencies may be necessary.

Aryl hydrocarbon receptor in mesenchymal stromal cells: new frontiers in AhR biology

Mesenchymal stromal cells (MSCs) are nonhematopoietic cells that have been clinically explored as investigational cellular therapeutics for tissue injury regeneration and immune-mediated diseases. Their pharmaceutical properties arise from activation of endogenous receptors and transcription factors leading to a paracrine effect which mirror the biology of progenitors from which they arise. The aryl hydrocarbon receptor (AhR) is a transcription factor that has been extensively studied as an environmental sensor for xenobiotics, but recent findings suggest it can modulate immunological functions. Both genetic and pharmacological investigations revealed that MSCs express AhR and that it plays roles in inflammation, immunomodulation, and mesodermal plasticity of endogenous MSCs. Further, AhR has been shown to interact with key signaling cascades associated with these conditions. Therefore, AhR has potential to be an attractive target in both endogenous and culture-adapted MSCs for novel therapeutics to treat inflammation and other age-related disorders.

Integrative Analysis of MicroRNAs and mRNAs in LPS-Induced Macrophage Inflammation Based on Adipose Tissue Stem Cell Therapy

Severe inflammation can lead to multiple organ dysfunction syndrome, which has high mortality. Adipose-derived stem cells have been shown to affect the inflammatory response of macrophages. However, the molecular mechanism of the anti-inflammatory capacity of adipose-derived stem cells (ADSCs) remains to be understood. In the present study, a macrophage inflammation model was established by LPS, and treated with different volumes of ADSC supernatant. Then, we investigated the key genes in the LPS group and treatment group by RT-PCR, RNA sequencing technology, and bioinformatics analysis. A total of 26 miRNAs and 11,882 mRNAs were differentially expressed between them. The expression of 15 of the miRNAs (9 upregulated and 6 downregulated) was confirmed by RT-PCR. GO and KEGG pathway analyses of the targets of the 9 significantly upregulated miRNAs showed that they were related to immune system process, inflammatory response, lipopolysaccharide, and TNF-α, NF-κB, Toll-like receptor, and MAPK signaling pathways. Moreover, a miRNA-mRNA network also revealed 8 important genes (Mapkapk2, Sepp1, Cers6, Snn, ZfP568, Ccdc93, Pofut1, Pik3cd). We finally confirmed the expression of these 8 targeted genes by performing the RT-PCR analysis. This study may provide a new understanding of the molecular mechanism of ADSCs in the inflammatory response related to multiple miRNAs and mRNAs.

Adipose-derived mesenchymal stem cells attenuate acute lung injury and improve the gut microbiota in septic rats

Background

We hypothesized that adipose-derived mesenchymal stem cells (ADMSCs) may ameliorate sepsis-induced acute lung injury (ALI) and change microorganism populations in the gut microbiota, such as that of Firmicutes and Bacteroidetes.

Methods

A total of 60 male adult Sprague-Dawley (SD) rats were separated into three groups: the sham control (SC) group, the sepsis induced by cecal ligation and puncture (CLP) group, and the ADMSC treatment (CLP-ADMSCs) group, in which rats underwent the CLP procedure and then received 1 × 10⁶ ADMSCs. Rats were sacrificed 24 h after the SC or CLP procedures. To study the role of ADMSCs during ALI caused by sepsis and examine the impact of ADMSCs on the gut microbiome composition, rat lungs were histologically evaluated using hematoxylin and eosin (H&E) staining, serum levels of pro-inflammatory factors were detected using enzyme-linked immunosorbent assay (ELISA), and fecal samples were collected and analyzed using 16S rDNA sequencing.

Results

The serum levels of inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-6, were significantly increased in rats after the CLP procedure, but were significantly decreased in rats treated with ADMSCs. Histological evaluation of the rat lungs yielded results consistent with the changes in IL-6 levels among all groups. Treatment with ADMSCs significantly increased the diversity of the gut microbiota in rats with sepsis. The principal coordinates analysis (PCoA) results showed that there was a significant difference between the gut microbiota of the CLP-ADMSCs group and that of the CLP group. In rats with sepsis, the proportion of Escherichia–Shigella (P = 0.01) related to lipopolysaccharide production increased, and the proportion of Akkermansia (P = 0.02) related to the regulation of intestinal mucosal thickness and the maintenance of intestinal barrier function decreased. These changes in the gut microbiota break the energy balance, aggravate inflammatory reactions, reduce intestinal barrier functions, and promote the translocation of intestinal bacteria. Intervention with ADMSCs increased the proportion of beneficial bacteria, reduced the proportion of harmful bacteria, and normalized the gut microbiota.

Conclusions

Therapeutically administered ADMSCs ameliorate CLP-induced ALI and improves gut microbiota, which provides a potential therapeutic mechanism for ADMSCs in the treatment of sepsis.

Circular RNA expression in the lungs of a mouse model of sepsis induced by cecal ligation and puncture

Circular RNAs (circRNAs) are novel endogenous RNAs with vital roles in the pathology of various diseases. However, their role in sepsis-induced lung injury is unknown. In this study, high-throughput gene sequencing was used to analyze the expression profiles of circRNAs in lung specimens of mice grouped by acute lung injury induced by cecal ligation and puncture (CLP) and sham. To identify differentially expressed circRNAs, the left lungs of sham (n = 3) and CLP (n = 3) mice were used for high-throughput sequencing. A total of 919 circRNAs were identified. Of these, 38 circRNAs showed significantly different expression levels between the groups (P < 0.05, fold change ≥2). The levels of 20 circRNAs were up-regulated and those of 18 others were down-regulated. In bioinformatics analysis of the source genes of these circRNAs, the genes were closely associated with the inflammatory response (e.g., the TGF-β, MAPK, Fc gamma R-mediated phagocytic, and VEGF pathways). Eight circRNAs with large intergroup differences, small intragroup differences, and high expression were selected for further validation by qRT-PCR. Two of the eight were significantly different. These two circRNAs were annotated with circRNA/miRNA interaction information downloaded from the TargetScan and miRanda databases and visualized. Our results provide novel insights into the roles of circRNAs in sepsis-induced acute lung injury.

Extracellular Vesicles From Adipose Tissue-Derived Stem Cells Affect Notch-miR148a-3p Axis to Regulate Polarization of Macrophages and Alleviate Sepsis in Mice

Extracellular vesicles (EVs) from adipose tissue-derived stem cells have been reported to attenuate lipopolysaccharide (LPS) induced inflammation and sepsis while the specific mechanism is unclear. This study explored the underlying molecular mechanisms of EVs from adipose tissue-derived stem cells in reducing inflammation. LPS- induced macrophage models and mice model were established to mimic inflammation in vitro and in vivo. EVs were extracted from adipose tissue-derived stem cells and identified. It was found that proinflammatory cytokines, including IL-1β, IL-6, and TNF-α, substantially decreased after EVs were applied to LPS-stimulated macrophages and mice, and thus, LPS induced M1 polarization was inhibited and sepsis was strongly alleviated. In the LPS induced macrophages, the expression of Notch signaling molecules and the activation of the NF-κB pathway were substantially decreased after the administration of EVs. Then, RBP-J ^-/- mice and macrophages were used. It was found that the miR-148a-3p level was significantly lower in the RBP-J ^-/- macrophages than in the wildtype macrophages. In the LPS induced macrophages, the increasing of miR-148a-3p was milder in the RBP-J ^-/- macrophages than in the wild type macrophages. Then, miR-148a-3p was overexpressed in macrophages and mice, and we found that the expression of proinflammatory cytokines was increased both in vivo and in vitro. The protective effect of EVs in LPS induced sepsis was diminished by the overexpression of miR-148a-3p. In conclusion, we proved that EVs could attenuate inflammation and further protect organ function by regulating the Notch-miR148a-3p signaling axis and then decreasing macrophage polarization to M1.

Mesenchymal Stem Cells Attenuate Lipopolysaccharide-Induced Inflammatory Response in Human Uterine Smooth Muscle Cells

Objective  The aim of this study was to determine if mesenchymal stem cells (MSCs) would suppress the inflammatory response in human uterine cells in an in vitro lipopolysaccharide (LPS)-based preterm birth (PTB) model. Study Design  Cocultures of human uterine smooth muscle cells (HUtSMCs) and MSCs were exposed to 5 μg/mL LPS for 4 hours and further challenged with 1 μg/mL LPS for a subsequent 24 hours. Key elements of the parturition cascade regulated by toll-like receptors (TLRs) through activation of mitogen-activated protein kinases (MAPKs) were quantified in culture supernatant as biomarkers of MSC modulation. Results  Coculture with MSCs significantly attenuated TLR-4, p-JNK, and p- extracellular signal-regulated kinase 1/2 (ERK1/2) protein levels compared with HUtSMCs monoculture ( p  = 0.05). In addition, coculture was associated with significant inhibition of proinflammatory cytokines interleukin (IL)-6 and IL-8 ( p  = 0.0001) and increased production of anti-inflammatory cytokines IL-10 and transforming growth factor (TGF)-β1 ( p  = 0.0001). Conclusion  MSCs appear to play a role in significantly attenuating LPS-mediated inflammation via alteration of down-stream MAPKs. MSCs may represent a novel, cell-based therapy in women with increased risk of inflammatory-mediated preterm birth.

Enhanced Effect of IL-1β-Activated Adipose-Derived MSCs (ADMSCs) on Repair of Intestinal Ischemia-Reperfusion Injury via COX-2-PGE2 Signaling

Adipose-derived mesenchymal stem cells (ADMSCs) have been used for treating tissue injury, and preactivation enhances their therapeutic effect. This study is aimed at investigating the therapeutic effect of activated ADMSCs by IL-1β on the intestinal ischaemia-reperfusion (IR) injury and exploring potential mechanisms. ADMSCs were pretreated with IL-1β in vitro, and activation of ADMSCs was assessed by α-SMA and COX-2 expressions and secretary function. Activated ADMSCs was transplanted into IR-injured intestine in a mouse model, and therapeutic effect was evaluated. In addition, to explore underlying mechanisms, COX-2 expression was silenced to investigate its role in activated ADMSCs for treatment of intestinal IR injury. When ADMSCs were pretreated with 50 ng/ml IL-1β for 24 hr, expressions of α-SMA and COX-2 were significantly upregulated, and secretions of PGE₂, SDF-1, and VEGF were increased. When COX-2 was silenced, the effect of IL-1β treatment was abolished. Activated ADMSCs with IL-1β significantly suppressed inflammation and apoptosis and enhanced healing of intestinal IR injury in mice, and these effects were impaired by COX-2 silencing. The results of RNA sequencing suggested that compared with the IR injury group activated ADMSCs induced alterations in mRNA expression and suppressed the activation of the NF-κB-P65, MAPK-ERK1/2, and PI3K-AKT pathways induced by intestinal IR injury, whereas silencing COX-2 impaired the suppressive effect of activated ADMSCs on these pathway activations induced by IR injury. These data suggested that IL-1β pretreatment enhanced the therapeutic effect of ADMSCs on intestinal IR injury repairing via activating ADMSC COX-2-PGE₂ signaling axis and via suppressing the NF-κB-P65, MAPK-ERK1/2, and PI3K-AKT pathways in the intestinal IR-injured tissue.

Lights and Shadows in the Use of Mesenchymal Stem Cells in Lung Inflammation, a Poorly Investigated Topic in Cystic Fibrosis

Mesenchymal stem cells (MSCs) are multipotent non-hematopoietic stem cells residing in many tissues, including the lung. MSCs have long been regarded as a promising tool for cell-based therapy because of their ability to replace damaged tissue by differentiating into the resident cell and repopulating the injured area. Their ability to release soluble factors and extracellular vesicles has emerged as crucial in the resolution of inflammation and injury. There is a growing literature on the use of MSCs and MSC secretome to hamper inflammation in different lung pathologies, including: asthma, pneumonia, acute lung injury (ALI), pulmonary hypertension, and chronic obstructive pulmonary disease (COPD). However, their potential therapeutic role in the context of Cystic Fibrosis (CF) lung inflammation is still not fully characterized. CF morbidity and mortality are mainly due to progressive lung dysfunction. Lung inflammation is a chronic and unresolved condition that triggers progressive tissue damage. Thus, it becomes even more important to develop innovative immunomodulatory therapies aside from classic anti-inflammatory agents. Here, we address the main features of CF and the implications in lung inflammation. We then review how MSCs and MSC secretome participate in attenuating inflammation in pulmonary pathologies, emphasizing the significant potential of MSCs as new therapeutic approach in CF.

Umbilical Cord Blood Mesenchymal Stem Cells Enhance Lipopolysaccharide-Induced IL-10 and IL-37 Production in THP-1 Cells

Umbilical cord blood mesenchymal stem cells (UCB-MSCs) have been shown to be a source of stem cells for use in cellular therapies and have immunomodulatory effects on several immune cells in an inflammatory environment. However, whether UCB-MSCs have immunomodulatory effects against lipopolysaccharide (LPS)-induced inflammatory cytokine secretion in macrophages and whether it is involved in phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway remain unclear. After co-culture of UCB-MSCs and phorbol 12-myristate 13-acetate (PMA)-activated human THP-1 cells using a transwell system, it showed that LPS significantly induced increases in the expression levels of interleukin 10 (IL-10), interleukin 37 (IL-37), phospho-PI3K (p-PI3K), and phospho-Akt (p-Akt) in macrophages. UCB-MSCs upregulated the expression of IL-10, IL-37, p-PI3K, and p-Akt, while it had no obvious effect on PI3K and Akt levels. Inhibitors of PI3K (LY294002) significantly suppressed the expression of IL-10, IL-37, p-PI3K, and p-Akt; however, it had no effect on the expression levels of PI3K and Akt. The present study demonstrated that UCB-MSCs increased the LPS-stimulated expression of IL-10 and IL-37 in macrophages through the PI3K/Akt signaling pathway.

Propylene glycol alginate sodium sulphate attenuates LPS-induced acute lung injury in a mouse model

Propylene glycol alginate sodium sulphate, a sulphated polysaccharide, has been used to treat hyperlipidaemia and ischaemia–reperfusion injury of liver. This study aimed to investigate the effect of propylene glycol alginate sodium sulphate on LPS-induced acute lung injury. Propylene glycol alginate sodium sulphate was injected intraperitoneally into male C57BL/6 mice with or without LPS administration. Survival rates were calculated. Serum, bronchoalveolar lavage fluid and lung tissues were collected to determine lung histology, wet/dry ratio, Evans blue albumin permeability, protein levels, the counts of immune cells and the levels of inflammatory cytokines and chemokines. Serum alanine aminotransferase, aspartate transaminase, creatinine and blood urea nitrogen levels were also measured. Additionally, NF-κB signalling was detected in the lung. Propylene glycol alginate sodium sulphate treatment significantly improved the survival of mice suffering from LPS. Lung histological injury, wet/dry ratio, Evans blue albumin permeability, neutrophils and the inflammatory cytokines and chemokines were significantly reduced by propylene glycol alginate sodium sulphate treatment. NF-κB signalling was significantly inhibited by propylene glycol alginate sodium sulphate in the lung of mice subjected to LPS. Furthermore, serum alanine aminotransferase, aspartate transaminase, creatinine and blood urea nitrogen levels were also significantly decreased after propylene glycol alginate sodium sulphate administration. This study suggests that NF-κB signalling and inhibition of pro-inflammatory cytokines, chemokines and neutrophil accumulation may be involved in the process of acute lung injury attenuation by propylene glycol alginate sodium sulphate.

Influence of tumour necrosis factor alpha on epithelial-mesenchymal transition of oral cancer cells in co-culture with mesenchymal stromal cells

Tumour progression in head and neck squamous cell carcinoma (HNSCC) is influenced by the surrounding stroma and inflammatory cytokines such as tumour necrosis factor alpha (TNF-α). The aim of this study was to test the hypothesis that TNF-α modulates the interactions of HNSCC cell line PCI-13 and bone marrow mesenchymal stromal cells (BMSCs) and influences markers of epithelial-mesenchymal transition (EMT). Following induction with TNF-α, mono- and co-cultures of BMSCs and the established HNSCC cell line PCI-13 were analyzed; protein expression of E-cadherin and vimentin and qRT-PCR expression of Snail, Twist, MMP14, vimentin, E-cadherin, and β-catenin were examined, and changes in cellular AKT signalling were analyzed. TNF-α induced a significant decrease in E-cadherin (64.5±6.0%, P=0.002) and vimentin (10.4±3.5%, P=0.04) protein expression in co-cultured PCI-13, while qRT-PCR showed a significant increase in β-catenin (BMSCs P<0.0001; PCI-13 P=0.0005) and Snail (BMSCs P=0.009; PCI-13 P=0.01). TNF-α also resulted in a down-regulation of AKT downstream targets S6 (38.7±20.9%, P=0.01), p70S6 (16.7±12%, P=0.05), RSK1 (23.6±28.8%, P=0.02), and mTOR (27.4±17.5%, P=0.004) in BMSC co-cultures. In summary, while reducing the expression of vimentin and AKT-signalling in PCI-13 and BMSC, respectively, TNF-α introduced an inflammatory-driven tumour-stroma transition, marked by an increased expression of markers of EMT.

Sini decoction ameliorates sepsis-induced acute lung injury via regulating ACE2-Ang (1-7)-Mas axis and inhibiting the MAPK signaling pathway

Sepsis, as life-threatening organ dysfunction caused by a dysregulated host response to infection, is characterized by the extensive release of cytokines and other mediators. Sini decoction (SND), a traditional Chinese prescription medicine, has been used clinically for the treatment of sepsis. But its explicit mechanism of action is still unclear. The present study aims to evaluate the potential protective effects of SND on sepsis-induced acute lung injury (ALI). After SND intervention, the lung tissues of each experimental group were collected. H&E sections were used to observe the pathological changes of lung tissue, and alveolar lavage fluid was collected to detect the infiltration of inflammatory cells. Level of inflammatory factors in lung tissue were analyzed by qRT-PCR. The change of Renin angiotensin system (RAS), as well as downstream MAPK/NF-κB signaling pathways were measured by Western blot. For in vitro experiments, human umbilical vein endothelial cells (HUVECs) were pretreated with lipopolysaccharide (LPS) and treated with SND. Subsequently, the expression levels of RAS and MAPK/NF-κB signaling pathways were measured by Western blot. In vivo, we found that SND significantly attenuated sepsis-induced pathological injury in the lung. SND also inhibited LPS-mediated inflammatory cell infiltration, the expression of pro-apoptotic proteins and the production of IL-6, IL-1β, TNF-α and MCP-1. In vitro, experiments using a co-culture of HUVECs with SND showed that there was a decrease in pro-apoptotic protein and pro-inflammatory mediator. In this research, we also found that SND protective action could be attributed to the regulation of renin-angiotensin system (RAS). MAPKs and NF-κB pathways. To conclude, our study demonstrated that SND ameliorates sepsis-induced-ALI via regulating ACE2-Ang (1-7)-Mas axis and inhibiting the MAPK signaling pathway.

Mesenchymal stem cell therapy for the treatment of inflammatory diseases: Challenges, opportunities, and future perspectives

Mesenchymal stem cells (MSCs) are promising alternative agents for the treatment of inflammatory disorders due to their immunomodulatory functions, and several clinical trials on MSC-based products are currently being conducted. In this review, we discuss recent progress made on the use of MSCs as immunomodulatory agents, developmental challenges posed by MSC-based therapy, and the strategies being used to overcome these challenges. In this context, current understanding of the mechanisms responsible for MSC interactions with the immune system and the molecular responses of MSCs to inflammatory signals are discussed. The immunosuppressive activities of MSCs are initiated by cell-to-cell contact and the release of immuno-regulatory molecules. By doing so, MSCs can inhibit the proliferation and function of T cells, natural killer cells, B cells, and dendritic cells, and can also increase the proliferation of regulatory T cells. However, various problems, such as low transplanted cell viability, poor homing and engraftment into injured tissues, MSC heterogeneity, and lack of adequate information on optimum MSC doses impede clinical applications. On the other hand, it has been shown that the immunomodulatory activities and viabilities of MSCs might be enhanced by 3D-cultured systems, genetic modifications, preconditioning, and targeted-delivery.

Effect of Comedications and Endotoxins on Mesenchymal Stem Cell Secretomes, Migratory and Immunomodulatory Capacity

Mesenchymal stem cells (MSCs) are becoming an increasingly popular therapeutic option among patients with a broad range of ailments to modulate immunity and induce regeneration. The majority of patients receiving these MSC therapies are on concurrent medication or have ongoing infection. In the present study, we examined the effect of immunosuppressive drugs and lipopolysaccharides (LPS)/endotoxins on the secretory profile, migration towards site of injury, and suppression of lymphocyte proliferation of bone marrow-derived MSCs (BMSCs). Generally, LPS coculture augmented the secretory capacity of BMSCs while exposure to immunosuppressive drugs resulted primarily in no change or attenuated secretion, with some cases of increased secretion, dependent on the cytokine assayed. Among the immunosuppressants evaluated, Hydrocortisone had the most widespread inhibitory effect, while LPS from E. coli O111:B4 had the most potent stimulatory effect. In addition, we also showed that Hydrocortisone or LPS from E. coli O111:B4 affected the migratory and immunosuppressive capacity of BMSCs. Following simulation with Hydrocortisone, BMSC migration was attenuated, and immunosuppressive capacity against T cell proliferation was enhanced, however, the opposite effects were seen with LPS from E. coli O111:B4. Our data suggests that the clinical outcomes of MSC-based therapy are affected by the use of immunosuppressive medication or the presence of endotoxemia in patients.

Effects of FM0807, a novel curcumin derivative, on lipopolysaccharide-induced inflammatory factor release via the ROS/JNK/p53 pathway in RAW264.7 cells

Purpose: Sepsis is a systemic inflammatory response caused by infection. Curcumin is known to have antioxidant and anti-inflammatory activities. FM0807, a curcumin derivative, was investigated in the present study to determine its effect on cytokines and the possible molecular mechanism. Main methods: The experiments were carried out in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Cell viability was measured by MTT assay. ELISA, Griess assays, fluorescence-based quantitative PCR, flow cytometric analysis, 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) experiments, and Western blotting were carried out to assess the potential effects of FM0807 on LPS-induced RAW 264.7 cells. Significant findings: FM0807 had no cytotoxic effects on RAW 264.7 cells. Furthermore, pretreatment with FM0807 inhibited the inflammatory factor tumor necrosis factor-α (TNF-α), interleukin (IL) 1β (IL-1β), IL-6, and inducible nitric oxide synthase (iNOS) at the protein and gene levels. FM0807 also inhibited the production of reactive oxygen species (ROS) and apoptosis. In addition, the activation of the ROS/JNK (c-jun NH₂-terminal kinase)/p53 signaling pathway was inhibited by FM0807 in RAW 264.7 cells in vitro. Conclusion: FM0807 has anti-inflammatory activity in vitro, which suggests a potential clinical application in sepsis. The anti-inflammatory activity of FM0807 may be mediated by the ROS/JNK/p53 signaling pathway.

Anti TNF-α therapy in patients with relapsed and refractory Langerhans cell histiocytosis: a phase II study

Tumor necrosis factor alpha (TNF-α) is produced in Langerhans cell histiocytosis (LCH) lesions and is elevated in plasma of patients with active LCH. It has been postulated that TNF-α may play a role in the pathophysiology of LCH. Etanercept, an anti-TNF-α antibody, has been used in TNF-modulated diseases such as rheumatoid arthritis (RA). We conducted a phase II study to determine the efficacy of etanercept for patients with refractory or relapsed LCH. Five LCH patients who had failed at least 2 prior treatments (range 2-9) received etanercept at a dose of 0.4 mg/kg twice weekly for up to a total of 24 doses. Disease response was assessed at 4 and 8 weeks. None of the five patients had improvement in their disease with etanercept treatment. Three progressed at week 4 and 1 progressed at week 8. One subject died after 3 weeks of treatment from disease progression. During the study, only one drug-related toxicity was noted which spontaneously resolved. The study was concluded early due to lack of response to etanercept and insufficient accrual rate. This data suggests that etanercept as given in this study may not be effective for relapsed or refractory LCH. However, the number of patients treated was not adequate enough to power this study and it is possible that a different dose and regimen of etanercept may be required to successfully treat this disease.