Xenogeneic human umbilical cord-derived mesenchymal stem cells reduce mortality in rats with acute respiratory distress syndrome complicated by sepsis. Oncotarget. 2017;8:45626-45642. [PMID: 28484089 PMCID: PMC5542214 DOI: 10.18632/oncotarget.17320]

Long term outcomes of intracarotid arterial transfusion of circulatory-derived autologous CD34 + cells for acute ischemic stroke patients-A randomized, open-label, controlled phase II clinical trial

BACKGROUND

This phase II randomized controlled trial tested whether the intracarotid arterial administration (ICAA) of autologous CD34 + cells to patients within 14 ± 7 days after acute ischemic stroke (IS) could be safe and further improve short- and long-term outcomes.

METHODS

Between January 2018 and March 2022, 28 consecutive patients were equally randomly allocated to the cell-treated group (CD34 + cells/3.0 × 107/patient) or the control group (receiving optimal medical therapy). CD34 + cells were transfused into the ipsilateral brain infarct zone of cell-treated patients via the ICAA in the catheterization room.

RESULTS

The results demonstrated 100% safety and success rates for the procedure, and no long-term tumorigenesis was observed in cell-treated patients. In cell-treated patients, the angiogenesis capacity of circulating endothelial progenitor cells (EPCs)/Matrigel was significantly greater after treatment than before treatment with granulocyte colony-stimulating factor (all p < 0.001). Blood samples from the right internal jugular vein of the cell-treated patients presented significantly greater levels of the stromal cell-derived factor 1α/EPC at 5, 10 and 30 min compared with 0 min (all p < 0.005). The National Institute of Health Stroke Scale scores were similar upon presentation, but a greater response was observed by Days 30 and 90 in the cell-treated group than in the control group. Tc-99 m brain perfusion was significantly greater at 180 days in the cell-treated group than in the control group (p = 0.046). The combined long-term end points (defined as death/recurrent stroke/or severe disability) were notably lower in the control group compared with the cell-treated group (14.3% vs. 50.0%, p = 0.103).

CONCLUSION

Intracarotid transfusion of autologous CD34 + cells is safe and might improve long-term outcomes in patients with acute IS. Trial registration ISRCTN, ISRCTN15677760. Registered 23 April 2018- Retrospectively registered, https://doi.org/10.1186/ISRCTN15677760.

Role of mesenchymal stem cells in sepsis and their therapeutic potential in sepsis‑associated myopathy (Review)

Sepsis‑induced myopathy (SIM) is one of the leading causes of death in critically ill patients. SIM mainly involves the respiratory and skeletal muscles of patients, resulting in an increased risk of lung infection, aggravated respiratory failure, and prolonged mechanical ventilation and hospital stay. SIM is also an independent risk factor associated with increased mortality in critically ill patients. At present, no effective treatment for SIM has yet been established. However, mesenchymal stem cells (MSCs) have emerged as a promising therapeutic approach and have been utilized in the treatment of various clinical conditions. A significant body of basic and clinical research supports the efficacy of MSCs in managing sepsis and muscle‑related diseases. This literature review aims to explore the relationship between MSCs and sepsis, as well as their impact on skeletal muscle‑associated diseases. Additionally, the present review discusses the potential mechanisms and therapeutic benefits of MSCs in the context of SIM.

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.

Efficacy and Safety of Umbilical Cord-Derived Mesenchymal Stromal Cell Therapy in Preclinical Models of Sepsis: A Systematic Review and Meta-analysis

BACKGROUND

In preclinical studies, mesenchymal stromal cells (MSCs), including umbilical cord-derived MSCs (UC-MSCs), demonstrate the ability to modulate numerous pathophysiological processes related to sepsis; however, a systematic synthesis of the literature is needed to assess the efficacy of UC-MSCs for treating sepsis.

OBJECTIVE

To examine the effects of UC-MSCs on overall mortality (primary outcome) as well as on organ dysfunction, coagulopathy, endothelial permeability, pathogen clearance, and systemic inflammation (secondary outcomes) at prespecified time intervals in preclinical models of sepsis.

METHODS

A systematic search was conducted on Embase, Ovid MEDLINE, and Web of Science up to June 20, 2023. Preclinical controlled studies using in vivo sepsis models with systemic UC-MSC administration were included. Meta-analyses were conducted and expressed as odds ratios (OR) and ratios of the weighted means with 95% CI for categorical and continuous data, respectively. Risk of bias was assessed with the SYRCLE tool.

RESULTS

Twenty-six studies (34 experiments, n = 1258 animals) were included in this review. Overall mortality was significantly reduced with UC-MSC treatment as compared to controls (OR: 0.26, 95% CI: 0.18-0.36). At various prespecified time intervals, UC-MSCs reduced surrogate measures of organ dysfunction related to the kidney, liver, and lung; reduced coagulopathy and endothelial permeability; and enhanced pathogen clearance from multiple sites. UC-MSCs also modulated systemic inflammatory mediators. No studies were rated as low risk across all SYCLE domains.

CONCLUSIONS

These results demonstrate the efficacy of UC-MSC treatment in preclinical sepsis models and highlight their potential as a therapeutic intervention for septic shock.

Engineered extracellular vesicles carrying let-7a-5p for alleviating inflammation in acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening respiratory condition characterized by severe inflammation and lung tissue damage, frequently causing rapid respiratory failure and long-term complications. The microRNA let-7a-5p is involved in the progression of lung injury, inflammation, and fibrosis by regulating immune cell activation and cytokine production. This study aims to use an innovative cellular electroporation platform to generate extracellular vesicles (EVs) carring let-7a-5p (EV-let-7a-5p) derived from transfected Wharton's jelly-mesenchymal stem cells (WJ-MSCs) as a potential gene therapy for ALI.

METHODS

A cellular nanoporation (CNP) method was used to induce the production and release of EV-let-7a-5p from WJ-MSCs transfected with the relevant plasmid DNA. EV-let-7a-5p in the conditioned medium were isolated using a tangential flow filtration (TFF) system. EV characterization followed the minimal consensus guidelines outlined by the International Society for Extracellular Vesicles. We conducted a thorough set of therapeutic assessments, including the antifibrotic effects using a transforming growth factor beta (TGF-β)-induced cell model, the modulation effects on macrophage polarization, and the influence of EV-let-7a-5p in a rat model of hyperoxia-induced ALI.

RESULTS

The CNP platform significantly increased EV secretion from transfected WJ-MSCs, and the encapsulated let-7a-5p in engineered EVs was markedly higher than that in untreated WJ-MSCs. These EV-let-7a-5p did not influence cell proliferation and effectively mitigated the TGF-β-induced fibrotic phenotype by downregulating SMAD2/3 phosphorylation in LL29 cells. Furthermore, EV-let-7a-5p regulated M2-like macrophage activation in an inflammatory microenvironment and significantly induced interleukin (IL)-10 secretion, demonstrating their modulatory effect on inflammation. Administering EVs from untreated WJ-MSCs slightly improved lung function and increased let-7a-5p expression in plasma in the hyperoxia-induced ALI rat model. In comparison, EV-let-7a-5p significantly reduced macrophage infiltration and collagen deposition while increasing IL-10 expression, causing a substantial improvement in lung function.

CONCLUSION

This study reveals that the use of the CNP platform to stimulate and transfect WJ-MSCs could generate an abundance of let-7a-5p-enriched EVs, which underscores the therapeutic potential in countering inflammatory responses, fibrotic activation, and hyperoxia-induced lung injury. These results provide potential avenues for developing innovative therapeutic approaches for more effective interventions in ALI.

Regenerative Effect of Mesenchymal Stem Cell on Cartilage Damage in a Porcine Model

Osteoarthritis (OA) is a major public and animal health challenge with significant economic consequences. Cartilage degradation plays a critical role in the initiation and progression of degenerative joint diseases, such as OA. Mesenchymal stem cells (MSCs) have become increasingly popular in the field of cartilage regeneration due to their promising results. The objective of this preclinical study was to evaluate the regenerative effects of mesenchymal stem cells (MSCs) in the repair of knee cartilage defects using a porcine model. Seven healthy LYD breed white pigs, aged 9-10 weeks and weighing approximately 20 ± 3 kg, were used in the experimental protocol. Full-thickness defects measuring 8 mm in diameter and 5 mm in depth were induced in the lateral femoral condyle of the posterior limbs in both knee joints using a sterile puncture technique while the knee was maximally flexed. Following a 1-week induction phase, the pig treatment groups received a 0.3 million/kg MSC transplant into the damaged knee region, while the placebo group received a control solution as a treatment. Magnetic resonance imaging (MRI), computerized tomography (CT), visual macroscopic examination, histological analysis, and cytokine concentration analysis were used to assess cartilage regeneration. The findings revealed that human adipose-derived mesenchymal stem cells (hADSCs) were more effective in repairing cartilage than pig umbilical cord-derived mesenchymal stem cells (pUCMSCs). These results suggest that MSC-based treatments hold promise as a treatment option for cartilage repair, which aid in the treatment of OA. However, further studies with larger sample sizes and longer follow-up periods are required to fully demonstrate the safety and efficacy of these therapies in both animals and humans.

Integrin α10β1-selected mesenchymal stem cells reduced hypercoagulopathy in a porcine model of acute respiratory distress syndrome

Mesenchymal stem cells (MSCs) have been studied for their potential benefits in treating acute respiratory distress syndrome (ARDS) and have reported mild effects when trialed within human clinical trials. MSCs have been investigated in preclinical models with efficacy when administered at the time of lung injury. Human integrin α10β1-selected adipose tissue-derived MSCs (integrin α10β1-MSCs) have shown immunomodulatory and regenerative effects in various disease models. We hypothesized that integrin α10β1 selected-MSCs can be used to treat a sepsis-induced ARDS in a porcine model when administering cells after established injury rather than simultaneously. This was hypothesized to reflect a clinical picture of treatment with MSCs in human ARDS. 12 pigs were randomized to the treated or placebo-controlled group prior to the induction of mild to moderate ARDS via lipopolysaccharide administration. The treated group received 5 × 106 cells/kg integrin α10β1-selected MSCs and both groups were followed for 12 h. ARDS was confirmed with blood gases and retrospectively with histological changes. After intervention, the treated group showed decreased need for inotropic support, fewer signs of histopathological lung injury including less alveolar wall thickening and reduction of the hypercoagulative disease state. The MSC treatment was not associated with adverse events over the monitoring period. This provides new opportunities to investigate integrin α10β1-selected MSCs as a treatment for a disease which does not yet have any definitive therapeutic options.

Early and Dose-Dependent Xenogeneic Mesenchymal Stem Cell Therapy Improved Outcomes in Acute Respiratory Distress Syndrome Rodent Through Ameliorating Inflammation, Oxidative Stress, and Immune Reaction

This study tested whether human umbilical cord-derived mesenchymal stem cells (HUCDMSCs) treatment effectively protected the rat lung against acute respiratory distress syndrome (ARDS) injury, and benefits of early and dose-dependent treatment. Rat pulmonary epithelial cell line L2 (PECL2) were categorized into G1 (PECL2), G2 (PECL2 + healthy rat lung-derived extraction/50 mg/ml co-cultured for 24 h), G3 (PECL2 + ARDS rat lung-derived extraction/50 mg/ml co-cultured for 24 h), and G4 (condition as G3 + HUCDMSCs/1 × 105/co-cultured for 24 h). The result showed that the protein expressions of inflammatory (HMGB-1/TLR-2/TLR-4/MAL/TRAM/MyD88/TRIF/TRAF6/IkB/NF-κB/IL-1β/TNF-α), oxidative-stress/mitochondrial-damaged (NOX-1/NOX-2/ASK1/p-MKK4/p-MKK7/JNKs/JUN/cytosolic-cytochrome-C/cyclophilin-D/DRP1), and cell-apoptotic/fibrotic (cleaved-caspase 3/cleaved-PARP/TGF-β/p-Smad3) biomarkers were significantly increased in G3 than in G1/G2 and were significantly reversed in G4 (all P < 0.001), but they were similar between G1/G2. Adult male rats (n = 42) were equally categorized into group 1 (normal control), group 2 (ARDS only), group 3 [ARDS + HUCDMSCs/1.2 × 106 cells intravenous administration at 3 h after 48 h ARDS induction (i.e., early treatment)], group 4 [ARDS + HUCDMSCs/1.2 × 106 cells intravenous administration at 24 h after 48 h ARDS induction (late treatment)], and group 5 [ARDS + HUCDMSCs/1.2 × 106 cells intravenous administration at 3 h/24 h after-48 h ARDS induction (dose-dependent treatment)]. By day 5 after ARDS induction, the SaO2%/immune regulatory T cells were highest in group 1, lowest in group 2, significantly lower in group 4 than in groups 3/5, and significantly lower in group 3 than in group 5, whereas the circulatory/bronchioalveolar lavage fluid inflammatory cells (CD11b-c+/LyG6+/MPO+)/circulatory immune cells (CD3-C4+/CD3-CD8+)/lung-leakage-albumin level/lung injury score/lung protein expressions of inflammatory (HMGB-1/TLR-2/TLR-4/MAL/TRAM/MyD88/TRIF/TRAF6/IκB-β/p-NF-κB/IL-1β/TNF-α)/fibrotic (p-SMad3/TGF-β), apoptosis (mitochondrial-Bax/cleaved-caspase-3)/oxidative-cell-stress (NOX-1/NOX-2/ASK1/p-MKK4/p-MKK7/p-JNKs/p-cJUN)/mitochondrial damaged (cyclophilin-D/DRP1/cytosolic-cytochrome-C) biomarkers displayed an opposite pattern of SaO2% among the groups (all P < 0.0001). Early administration was superior to and two-dose counterpart was even more superior to late HUCDMSCs treatment for protecting the lung against ARDS injury.

Mesenchymal stromal cells as treatment for acute respiratory distress syndrome. Case Reports following hematopoietic cell transplantation and a review

Acute respiratory distress syndrome (ARDS) is a life-threatening lung disease. It may occur during the pancytopenia phase following allogeneic hematopoietic cell transplantation (HCT). ARDS is rare following HCT. Mesenchymal stromal cells (MSCs) have strong anti-inflammatory effect and first home to the lung following intravenous infusion. MSCs are safe to infuse and have almost no side effects. During the Covid-19 pandemic many patients died from ARDS. Subsequently MSCs were evaluated as a therapy for Covid-19 induced ARDS. We report three patients, who were treated with MSCs for ARDS following HCT. Two were treated with MSCs derived from the bone marrow (BM). The third patient was treated with MSCs obtained from the placenta, so-called decidua stromal cells (DSCs). In the first patient, the pulmonary infiltrates cleared after infusion of BM-MSCs, but he died from multiorgan failure. The second patient treated with BM-MSCs died of aspergillus infection. The patient treated with DSCs had a dramatic response and survived. He is alive after 7 years with a Karnofsky score of 100%. We also reviewed experimental and clinical studies using MSCs or DSCs for ARDS. Several positive reports are using MSCs for sepsis and ARDS in experimental animals. In man, two prospective randomized placebo-controlled studies used adipose and BM-MSCs, respectively. No difference in outcome was seen compared to placebo. Some pilot studies used MSCs for Covid-19 ARDS. Positive results were achieved using umbilical cord and DSCs however, optimal source of MSCs remains to be elucidated using randomized trials.

Human umbilical cord mesenchymal stem cells ameliorate erectile dysfunction in rats with diabetes mellitus through the attenuation of ferroptosis

Background

Erectile dysfunction (ED), as one of the most prevalent consequences in male diabetic patients, has a serious impact on men's physical and mental health, and the treatment effect of diabetic mellitus erectile dysfunction (DMED) is often worse. Therefore, the development of a novel therapeutic approach is urgent. As stem cells with high differentiation potential, human umbilical cord mesenchymal stem cells (HUCMSCs) have been widely used in the treatment of diseases in other systems, and are expected to be a promising strategy for the treatment of DMED. In this study, we investigated the role of HUCMSCs in managing erectile function in rat models of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) and compared the effects of two different injection methods.

Methods

T1DM and T2DM ED rats were given labelled HUCMSCs by corpus cavernosum injection and tail vein injection, respectively. ICP and MAP were monitored simultaneously by electrical stimulation four weeks after injection to indicate the erectile function of rats. To track the development and colonisation capabilities of stem cells, we performed EdU assay with penile tissue. The histological changes of the penis were observed by hematoxylin–eosin staining, and Masson’s trichrome staining was conducted to evaluate the smooth muscle content and the degree of fibrosis in the rat penis. Then, we employed specific kits to measure the level of NO, cGMP, MDA, SOD and Fe in penis. Electron transmission microscopy was implemented to observe morphology of mitochondria. Besides, western blot and immunofluorescence staining were performed to demonstrate the expression of ferroptosis-related genes.

Results

We found that HUCMSCs improved erectile function in T1DM and T2DM ED rats, with no difference in efficacy between corpus cavernosum injection and tail vein injection. The EdU assay revealed that only a tiny percentage of HUCMSCs colonised the corpus cavernosum, while smooth muscle in the penis expanded and collagen decreased following HUCMSC injection. Moreover, the levels of oxidative stress in the penis of the rats given HUCMSCs were dramatically reduced, as was the tissue iron content. HUCMSCs normalised mitochondrial morphology within corpus cavernosum smooth muscle cells (CCSMCs), which were characteristically altered by high glucose. Furthermore, the expression of ferroptosis inhibitory genes SLC7A11 and GPX4 was obviously elevated in CCSMCs after stem cell management, but the abundances of ACSL4, LPCAT3 and ALOX15 showed the polar opposite tendency.

Conclusions

HUCMSCs can effectively and safely alleviate erectile dysfunction in T1DM and T2DM ED rats, while restoring erectile function by attenuating diabetes-induced ferroptosis in CCSMCs. Additionally, this study provides significant evidence for the development of HUCMSCs as a viable therapeutic strategy for DMED.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03147-w.

Intrarenal arterial administration of human umbilical cord-derived mesenchymal stem cells effectively preserved the residual renal function of diabetic kidney disease in rat

Background

This experimental study was designed as a preclinical study for testing the hypothesis that intrarenal arterial (IRA) transfusion of human umbilical cord-derived mesenchymal stem cells (HUCDMSCs) therapy preserved the residual renal function of diabetic kidney disease (DKD) in rat [induction by 5/6 nephrectomy of left kidney and right nephrectomy, followed by intraperitoneal administration of aminoguanidine (180 mg/kg) and streptozotocin (30 mg/kg)].

Methods

Animals (n = 24) were categorized into group 1 (sham-operated control), group 2 (DKD), group 3 [DKD + HUCDMSCs (2.1 × 10⁵/IRA injection at day 28 after CKD induction)] and group 4 [(DKD + HUCDMSCs (6.3 × 10⁵/IRA injection)].

Results

By day 60 after DKD induction, the kidneys were harvested and the result showed that the creatinine level, ratio of urine protein/urine creatinine and kidney injury score were lowest in group 1, highest in group 2 and significantly lower in group 4 than in group 3 (all p < 0.0001). The protein expressions of apoptotic (cleaved caspase-3/cleaved PARP/mitochondrial Bax), fibrotic (TGF-ß/p-Smad3), autophagic (ratio of LC3B-II/LC3B-I, Atg5/Beclin-1), oxidative stress (NOX-1/NOX-2/oxidized protein/p22phox), mitochondrial/DNA-damaged (cytosolic-cytochrome-C/DRP1/γ-H2AX) and inflammatory (MMP-9/TNF-α/p-NF-κB) biomarkers exhibited an identical pattern, whereas the protein expressions of angiogenesis factors (CD31/vWF/vascularity) exhibited an opposite pattern of creatinine level among the groups (all p < 0.0001). Histopathological findings demonstrated the renal tubular-damaged (KIM-1)/kidney fibrosis area/oxidative stress (8-OHdG + cells) expressed an identical pattern, whereas the podocyte components (ZO-1/synaptopodin/podocin) exhibited an opposite pattern of creatinine level among the groups (all p < 0.0001). No tumorigenesis or immune rejection event was identified.

Conclusion

IRA injection of xenogeneic MSCs was safe and effectively protected the residual renal function and architectural integrity in DKD rat.

Additional benefit of induced pluripotent stem cell-derived mesenchymal stem cell therapy on sepsis syndrome-associated acute kidney injury in rat treated with antibiotic

BACKGROUND

This study tested whether human induced-pluripotent stem-cell-derived mesenchymal-stem-cells (iPS-MSCs) would offer an additional benefit to the rodent with acute kidney injury (AKI) (ischemia for 1 h followed by reperfusion for 120 h) associated sepsis syndrome (SS) (by cecal-ligation-puncture immediately after AKI-induction) undergoing ciprofloxacin therapy.

RESULTS

Male-adult SD rats (n = 80) were categorized into group 1 (sham-operated-control, n = 10), group 2 (AKI + SS, n = 24), group 3 (AKI + SS + ciprofloxacin/3 mg/kg, orally for 120 h, n = 12), group 4 (AKI + SS + iPS-MSCs/1.2 × 10⁶/intravenously administered by 3 h after AKI, n = 12), group 5 (AKI + SS + iPS-MSCs/1.2 × 10⁶/intravenously administered by 18 h after AKI, n = 12), group 6 (AKI + SS + iPS-MSCs/1.2 × 10⁶/intravenously administered by 3 h after AKI induction + ciprofloxacin, n = 10] and euthanized by 120 h. The result showed that the mortality was significantly higher in group 2 than in other groups (all p < 0.01). The creatinine level was highest in group 2, lowest in group 1, significantly lower in group 6 than in groups 3, 4 and 5, (all p < 0.0001), but it showed no difference among the latter 3 groups. Flow cytometric analysis showed that the circulatory inflammatory cells (Ly6G/CD11^b/c), early (AN-V+/PI-)/late (AN-V+/PI+) apoptosis, and circulatory/splenic immune cells (CD3+/CD4+, CD3+/CD8a+) were highest in group 2, lowest in group 1, significantly lower in group 6 than in groups 3/4/5 and significantly lower in group 4 than in groups 3/5 (all p < 0.0001), but they showed no difference between groups 3/5. Protein expressions of oxidative-stress (NOX-1/NOX2/oxidized protein), apoptotic (cleaved-caspase3/cleaved-PARP/mitochondrial-Bax), fibrotic (TGF-ß/Smad3), inflammatory (MMP-9/IL-6/TNF-α) and autophagic (Atg5/Beclin) biomarkers in kidney exhibited an identical pattern of circulatory inflammatory cells (all p < 0.0001).

CONCLUSION

Combined iPS-MSCs-ciprofloxacin therapy was superior to either one alone for protecting AKI complicated by SS.

The Protective Benefit of Heme Oxygenase-1 Gene-Modified Human Placenta-Derived Mesenchymal Stem Cells in a N-Nitro-L-Arginine Methyl Ester-Induced Preeclampsia-Like Rat Model: Possible Implications for Placental Angiogenesis

We previously reported that cytoprotective Heme oxygenase-1, HO-1 (HMOX1) gene-modified human placenta-derived mesenchymal stem cell (HO-1-PMSC) improved placental vascularization in vitro. In the current study, we explored the protective benefit of HO-1-PMSC transplantation in a preeclampsia (PE)-like rat model. A model of PE was successfully constructed by intraperitoneal injection of N-nitro-L-arginine methyl ester (L-NAME). Blood pressure and urinary protein levels were measured. Doppler ultrasound was examined to understand uteroplacental perfusion. ELISA was used to examine the serum levels of VEGF, PlGF, sFlt-1, and sEng. The placentas and fetuses were weighed to verify the improvement in pregnancy outcome. Immunohistochemical and H&E staining was used to detect microvessel density (MVD) in placental tissues and kidney pathology, respectively. The distribution of GFP-labeled PMSC in the placenta were observed under fluorescence microscopy. Blood pressure and proteinuria were reduced and kidney damage was improved. PE rat models treated with PMSC and HO-1-PMSC exhibited an increase in the quality of fetuses and placentas, MVD, VEGF, and PlGF expression, but substantially decreased expression of sFlt-1 and sEng. Doppler ultrasound showed that the placental perfusion was improved. Green fluorescent tracing experiments verified that the cells were successfully transplanted into the placenta and distributed in the blood vessels, indicating that the cells might participate in the process of angiogenesis. These results indicate that therapy with HO-1-PMSC could improve placental vascular dysplasia, increase placental perfusion, control PE symptoms, and promote pregnancy outcome by regulating the balance of angiogenic and antiangiogenic factors or directly participating in the repair of placental vessels in a PE-like rat model.

Current therapeutic strategies for respiratory diseases using mesenchymal stem cells

Mesenchymal stromal/stem cells (MSCs) have a great potential to proliferate, undergo multi-directional differentiation, and exert immunoregulatory effects. There is already much enthusiasm for their therapeutic potentials for respiratory inflammatory diseases. Although the mechanism of MSCs-based therapy has been well explored, only a few articles have summarized the key advances in this field. We hereby provide a review over the latest progresses made on the MSCs-based therapies for four types of inflammatory respiratory diseases, including idiopathic pulmonary fibrosis, acute respiratory distress syndrome, chronic obstructive pulmonary disease, and asthma, and the uncovery of their underlying mechanisms from the perspective of biological characteristics and functions. Furthermore, we have also discussed the advantages and disadvantages of the MSCs-based therapies and prospects for their optimization.

Human Umbilical Cord-Derived Mesenchymal Stem Cell Therapy Effectively Protected the Brain Architecture and Neurological Function in Rat After Acute Traumatic Brain Injury

Intracranial hemorrhage from stroke and head trauma elicits a cascade of inflammatory and immune reactions detrimental to neurological integrity and function at cellular and molecular levels. This study tested the hypothesis that human umbilical cord–derived mesenchymal stem cell (HUCDMSC) therapy effectively protected the brain integrity and neurological function in rat after acute traumatic brain injury (TBI). Adult male Sprague-Dawley rats (n = 30) were equally divided into group 1 (sham-operated control), group 2 (TBI), and group 3 [TBI + HUCDMSC (1.2 × 10⁶ cells/intravenous injection at 3 h after TBI)] and euthanized by day 28 after TBI procedure. The results of corner test and inclined plane test showed the neurological function was significantly progressively improved from days 3, 7, 14, and 28 in groups 1 and 3 than in group 2, and group 1 than in group 3 (all P < 0.001). By day 28, brain magnetic resonance imaging brain ischemic volume was significantly increased in group 2 than in group 3 (P < 0.001). The protein expressions of apoptosis [mitochondrial-bax positive cells (Bax)/cleaved-caspase3/cleaved-poly(adenosine diphosphate (ADP)-ribose) polymerase], fibrosis (Smad3 positive cells (Smad3)/transforming growth factor-β), oxidative stress (NADPH Oxidase 1 (NOX-1)/NADPH Oxidase 2 (NOX-2)/oxidized-protein/cytochrome b-245 alpha chain (p22phox)), and brain-edema/deoxyribonucleic acid (DNA)–damaged biomarkers (Aquaporin-4/gamma H2A histone family member X ( (γ-H2AX)) displayed an identical pattern to neurological function among the three groups (all P < 0.0001), whereas the protein expressions of angiogenesis biomarkers (vascular endothelial growth factor/stromal cell–derived factor-1α/C-X-C chemokine receptor type 4 (CXCR4)) significantly increased from groups 1 to 3 (all P < 0.0001). The cellular expressions of inflammatory biomarkers (cluster of differentiation 14 (+) cells (CD14+)/glial fibrillary acidic protein positive cells (GFAP+)/ a member of a new family of EGF-TM7 molecules positive cells (F4/80+)) and DNA-damaged parameter (γ-H2AX) exhibited an identical pattern, whereas cellular expressions of neural integrity (hexaribonucleotide Binding Protein-3 positive cells (NeuN+)/nestin+/doublecortin+) exhibited an opposite pattern of neurological function among the three groups (all P < 0.0001). Xenogeneic HUCDMSC therapy was safe and it significantly preserved neurological function and brain architecture in rat after TBI.

Double overexpression of miR-19a and miR-20a in induced pluripotent stem cell-derived mesenchymal stem cells effectively preserves the left ventricular function in dilated cardiomyopathic rat

BACKGROUND

This study tested the hypothesis that double overexpression of miR-19a and miR-20a (dOex-mIRs) in human induced pluripotent stem cell (iPS)-derived mesenchymal stem cells (MSCs) effectively preserved left ventricular ejection fraction (LVEF) in dilated cardiomyopathy (DCM) (i.e., induced by doxorubicin) rat.

METHODS AND RESULTS

In vitro study was categorized into groups G1 (iPS-MSC), G2 (iPS-MSC^dOex-mIRs), G3 (iPS-MSC + H₂O₂/100uM), and G4 (iPS-MSC^dOex-mIRs + H₂O₂/100uM). The in vitro results showed the cell viability was significantly lower in G3 than in G1 and G2, and that was reversed in G4 but it showed no difference between G1/G2 at time points of 6 h/24 h/48 h, whereas the flow cytometry of intra-cellular/mitochondrial oxidative stress (DCFA/mitoSOX) and protein expressions of mitochondrial-damaged (cytosolic-cytochrome-C/DRP1/Cyclophilin-D), oxidative-stress (NOX-1/NOX2), apoptotic (cleaved-caspase-3/PARP), fibrotic (p-Smad3/TGF-ß), and autophagic (ratio of LC3B-II/LC3BI) biomarkers exhibited an opposite pattern of cell-proliferation rate (all p< 0.001). Adult-male SD rats (n=32) were equally divided into groups 1 (sham-operated control), 2 (DCM), 3 (DCM + iPS-MSCs/1.2 × 10⁶ cells/administered by post-28 day's DCM induction), and 4 (DCM + iPS-MSC^dOex-mIRs/1.2 × 10⁶ cells/administered by post-28 day's DCM induction) and euthanized by day 60 after DCM induction. LV myocardium protein expressions of oxidative-stress signaling (p22-phox/NOX-1/NOX-2/ASK1/p-MMK4,7/p-JNK1,2/p-cJUN), upstream (TLR-4/MAL/MyD88/TRIF/TRAM/ TFRA6/IKK_α/ß/NF-κB) and downstream (TNF-α/IL-1ß/MMP-9) inflammatory signalings, apoptotic (cleaved-PARP/mitochondrial-Bax), fibrotic (Smad3/TGF-ß), mitochondrial-damaged (cytosolic-cytochrome-C/DRP1/cyclophilin-D), and autophagic (beclin1/Atg5) biomarkers were highest in group 2, lowest in group 1 and significantly lower in group 4 than in group 3, whereas the LVEF exhibited an opposite pattern of oxidative stress (all p< 0.0001).

CONCLUSION

iPS-MSC^dOex-mIRs therapy was superior to iPS-MSC therapy for preserving LV function in DCM rat.

Human Umbilical Cord-Derived Mesenchymal Stem Cells for Acute Respiratory Distress Syndrome

OBJECTIVES

To investigate the safety, feasibility, and possible adverse events of single-dose human umbilical cord-derived mesenchymal stem cells in patients with moderate-to-severe acute respiratory distress syndrome.

DESIGN

Prospective phase I clinical trial.

SETTING

Medical center in Kaohsiung, Taiwan.

PATIENTS

Moderate-to-severe acute respiratory distress syndrome with a PaO2/FIO2 ratio less than 200.

INTERVENTIONS

Scaling for doses was required by Taiwan Food and Drug Administration as follows: the first three patients received low-dose human umbilical cord-derived mesenchymal stem cells (1.0 × 10 cells/kg), the next three patients with intermediate dose (5.0 × 10 cells/kg), and the final three patients with high dose (1.0 × 10 cells/kg) between December 2017 and August 2019.

MEASUREMENTS AND MAIN RESULTS

Nine consecutive patients were enrolled into the study. In-hospital mortality was 33.3% (3/9), including two with recurrent septic shock and one with ventilator-induced severe pneumomediastinum and subcutaneous emphysema. No serious prespecified cell infusion-associated or treatment-related adverse events was identified in any patient. Serial flow-cytometric analyses of circulating inflammatory biomarkers (CD14CD33/CD11b+CD16+/CD16+MPO+/CD11b+MPO+/CD14CD33+) and mesenchymal stem cell markers (CD26+CD45-/CD29+CD45-/CD34+CD45-/CD44+CD45-/CD73+CD45-/CD90+CD45-/CD105+CD45-/CD26+CD45-) were notably progressively reduced (p for trend < 0.001), whereas the immune cell markers (Helper-T-cell/Cytotoxity-T-cell/Regulatory-T-cell) were notably increased (p for trend < 0.001) after cell infusion.

CONCLUSIONS

The result of this phase I clinical trial showed that a single-dose IV infusion of human umbilical cord-derived mesenchymal stem cells was safe with favorable outcome in nine acute respiratory distress syndrome patients.

Umbilical cord-derived MSC and hyperbaric oxygen therapy effectively protected the brain in rat after acute intracerebral haemorrhage

This study tested the hypothesis that combined therapy with human umbilical cord‐derived mesenchymal stem cells (HUCDMSCs) and hyperbaric oxygen (HBO) was superior to either one on preserving neurological function and reducing brain haemorrhagic volume (BHV) in rat after acute intracerebral haemorrhage (ICH) induced by intracranial injection of collagenase. Adult male SD rats (n = 30) were equally divided into group 1 (sham‐operated control), group 2 (ICH), group 3 (ICH +HUCDMSCs/1.2 × 10⁶ cells/intravenous injection at 3h and days 1 and 2 after ICH), group 4 (ICH +HBO/at 3 hours and days 1 and 2 after ICH) and group 5 (ICH +HUCDMSCs‐HBO), and killed by day 28 after ICH. By day 1, the neurological function was significantly impaired in groups 2‐5 than in group 1 (P < .001), but it did not differ among groups 2 to 5. By days 7, 14 and 28, the integrity of neurological function was highest in group 1, lowest in group 2 and significantly progressively improved from groups 3 to 5 (all P < .001). By day 28, the BHV was lowest in group 1, highest in group 2 and significantly lower in group 5 than in groups 3/4 (all P < .0001). The protein expressions of inflammation (HMGB1/TLR‐2/TLR‐4/MyD88/TRAF6/p‐NF‐κB/IFN‐γ/IL‐1ß/TNF‐α), oxidative stress/autophagy (NOX‐1/NOX‐2/oxidized protein/ratio of LC3B‐II/LC3B‐I) and apoptosis (cleaved‐capspase3/PARP), and cellular expressions of inflammation (CD14+, F4/80+) in brain tissues exhibited an identical pattern, whereas cellular levels of angiogenesis (CD31+/vWF+/small‐vessel number) and number of neurons (NeuN+) exhibited an opposite pattern of BHV among the groups (all P < .0001). These results indicate that combined HUCDMSC‐HBO therapy offered better outcomes after rat ICH.

Mesenchymal stem/stromal cells as a valuable source for the treatment of immune-mediated disorders

Over recent years, mesenchymal stem/stromal cells (MSCs) and their potential biomedical applications have received much attention from the global scientific community in an increasing manner. Firstly, MSCs were successfully isolated from human bone marrow (BM), but in the next steps, they were also extracted from other sources, mostly from the umbilical cord (UC) and adipose tissue (AT). The International Society for Cellular Therapy (ISCT) has suggested minimum criteria to identify and characterize MSCs as follows: plastic adherence, surface expression of CD73, D90, CD105 in the lack of expression of CD14, CD34, CD45, and human leucocyte antigen-DR (HLA-DR), and also the capability to differentiate to multiple cell types including adipocyte, chondrocyte, or osteoblast in vitro depends on culture conditions. However, these distinct properties, including self-renewability, multipotency, and easy accessibility are just one side of the coin; another side is their huge secretome which is comprised of hundreds of mediators, cytokines, and signaling molecules and can effectively modulate the inflammatory responses and control the infiltration process that finally leads to a regulated tissue repair/healing or regeneration process. MSC-mediated immunomodulation is a direct result of a harmonic synergy of MSC-released signaling molecules (i.e., mediators, cytokines, and chemokines), the reaction of immune cells and other target cells to those molecules, and also feedback in the MSC-molecule-target cell axis. These features make MSCs a respectable and eligible therapeutic candidate to be evaluated in immune-mediated disorders, such as graft versus host diseases (GVHD), multiple sclerosis (MS), Crohn's disease (CD), and osteoarthritis (OA), and even in immune-dysregulating infectious diseases such as the novel coronavirus disease 2019 (COVID-19). This paper discussed the therapeutic applications of MSC secretome and its biomedical aspects related to immune-mediated conditions. Sources for MSC extraction, their migration and homing properties, therapeutic molecules released by MSCs, and the pathways and molecular mechanisms possibly involved in the exceptional immunoregulatory competence of MSCs were discussed. Besides, the novel discoveries and recent findings on immunomodulatory plasticity of MSCs, clinical applications, and the methods required for their use as an effective therapeutic option in patients with immune-mediated/immune-dysregulating diseases were highlighted.

Mesenchymal Stem Cell-Based Therapy for COVID-19: Possibility and Potential

A novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) has emerged in Wuhan, China since the end of December 2019 and has quickly spread all over the world in a matter of two months. To date, no specific treatment has been proven to be effective for coronavirus (COVID-19). With the rapid increase of infected patients and deaths, it is vital to explore an effective treatment for COVID-19. Current studies suggest that there exists cytokine storm in SARS-CoV-2-infected patients; some of the them will develop acute respiratory distress syndrome (ARDS) and multiple organ dysfunction, and even death. Mesenchymal stem cells (MSCs) possess the property of immunomodulation. Given the previous preclinical and clinical studies, MSCs therapy has shown safety and efficacy in the treatment of respiratory failure or ARDS. Based on similar principles, MSCs therapy may also be an effective therapy in the treatment of COVID-19. In this study, we summarized the clinical outcomes of MSCs for ARDS patients in some preclinical and clinical studies and discussed the application of MSCs for patients with COVID-19 in China and the related important issues with MSCs used during the outbreak.

Perinatal Cells: A Promising COVID-19 Therapy?

The COVID-19 pandemic has become a priority in the health systems of all nations worldwide. In fact, there are currently no specific drugs or preventive treatments such as vaccines. The numerous therapies available today aim to counteract the symptoms caused by the viral infection that in some subjects can evolve causing acute respiratory distress syndromes (ARDS) with consequent admission to intensive care unit. The exacerbated response of the immune system, through cytokine storm, causes extensive damage to the lung tissue, with the formation of edema, fibrotic tissues and susceptibility to opportunistic infections. The inflammatory picture is also aggravated by disseminated intravascular coagulation which worsens the damage not only to the respiratory system, but also to other organs. In this context, perinatal cells represent a valid strategy thanks to their strong immunomodulatory potential, their safety profile, the ability to reduce fibrosis and stimulate reparative processes. Furthermore, perinatal cells exert antibacterial and antiviral actions. This review therefore provides an overview of the characteristics of perinatal cells with a particular focus on the beneficial effects that they could have in patients with COVID-19, and more specifically for their potential use in the treatment of ARDS and sepsis.

Novel insights into the treatment of SARS-CoV-2 infection: An overview of current clinical trials

The emergence of the global pandemic caused by the novel SARS-CoV-2 virus has motivated scientists to find a definitive treatment or a vaccine against it in the shortest possible time. Current efforts towards this goal remain fruitless without a full understanding of the behavior of the virus and its adaptor proteins. This review provides an overview of the biological properties, functional mechanisms, and molecular components of SARS-CoV-2, along with investigational therapeutic and preventive approaches for this virus. Since the proteolytic cleavage of the S protein is critical for virus penetration into cells, a set of drugs, such as chloroquine, hydroxychloroquine, camostat mesylate have been tested in clinical trials to suppress this event. In addition to angiotensin-converting enzyme 2, the role of CD147 in the viral entrance has also been proposed. Mepolizumab has shown to be effective in blocking the virus's cellular entrance. Antiviral drugs, such as remdesivir, ritonavir, oseltamivir, darunavir, lopinavir, zanamivir, peramivir, and oseltamivir, have also been tested as treatments for COVID-19. Regarding preventive vaccines, the whole virus, vectors, nucleic acids, and structural subunits have been suggested for vaccine development. Mesenchymal stem cells and natural killer cells could also be used against SARS-CoV-2. All the above-mentioned strategies, as well as the role of nanomedicine for the diagnosis and treatment of SARS-CoV-2 infection, have been discussed in this review.

Mesenchymal stem cells as living anti-inflammatory therapy for COVID-19 related acute respiratory distress syndrome

Coronavirus disease 2019 (COVID-19), a pandemic disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), is growing at an exponential rate worldwide. Manifestations of this disease are heterogeneous; however, advanced cases often exhibit various acute respiratory distress syndrome-like symptoms, systemic inflammatory reactions, coagulopathy, and organ involvements. A common theme in advanced COVID-19 is unrestrained immune activation, classically referred to as a “cytokine storm”, as well as deficiencies in immune regulatory mechanisms such as T regulatory cells. While mesenchymal stem cells (MSCs) themselves are objects of cytokine regulation, they can secrete cytokines to modulate immune cells by inducing anti-inflammatory regulatory Treg cells, macrophages and neutrophils; and by reducing the activation of T and B cells, dendritic and nature killer cells. Consequently, they have therapeutic potential for treating severe cases of COVID-19. Here we discuss the unique ability of MSCs, to act as a “living anti-inflammatory”, which can “rebalance” the cytokine/immune responses to restore equilibrium. We also discuss current MSC trials and present different concepts for optimization of MSC therapy in patients with COVID-19 acute respiratory distress syndrome. 

Mesenchymal stem cells reverse EMT process through blocking the activation of NF-κB and Hedgehog pathways in LPS-induced acute lung injury

Acute lung injury (ALI) is a pulmonary disorder, which can result in fibrosis of the lung tissues. Recently, mesenchymal stem cell (MSC) has become a novel therapeutic method for ALI. However, the potential mechanism by which MSC regulates the progression of ALI remains blurry. The present study focused on investigating the mechanism underneath MSC-reversed lung injury and fibrosis. At first, we determined that coculture with MSC led to the inactivation of NF-κB signaling and therefore suppressed hedgehog pathway in LPS-treated MLE-12 cells. Besides, we confirmed that MSC-exosomes were responsible for the inhibition of EMT process in LPS-treated MLE-12 cells through transmitting miRNAs. Mechanism investigation revealed that MSC-exosome transmitted miR-182-5p and miR-23a-3p into LPS-treated MLE-12 cells to, respectively, target Ikbkb and Usp5. Of note, Usp5 interacted with IKKβ to hamper IKKβ ubiquitination. Moreover, co-inhibition of miR-182-5p and miR-23a-3p offset the suppression of MSC on EMT process in LPS-treated MLE-12 cells as well as in LPS-injured lungs of mice. Besides, the retarding effect of MSC on p65 nuclear translocation was also counteracted after co-inhibiting miR-182-5p and miR-23a-3p, both in vitro and in vivo. In summary, MSC-exosome transmitted miR-23a-3p and miR-182-5p reversed the progression of LPS-induced lung injury and fibrosis through inhibiting NF-κB and hedgehog pathways via silencing Ikbkb and destabilizing IKKβ.

Human Mesenchymal Stromal Cells Are Resistant to SARS-CoV-2 Infection under Steady-State, Inflammatory Conditions and in the Presence of SARS-CoV-2-Infected Cells

Previous studies reported on the safety and applicability of mesenchymal stem/stromal cells (MSCs) to ameliorate pulmonary inflammation in acute respiratory distress syndrome (ARDS). Thus, multiple clinical trials assessing the potential of MSCs for COVID-19 treatment are underway. Yet, as SARS-inducing coronaviruses infect stem/progenitor cells, it is unclear whether MSCs could be infected by SARS-CoV-2 upon transplantation to COVID-19 patients. We found that MSCs from bone marrow, amniotic fluid, and adipose tissue carry angiotensin-converting enzyme 2 and transmembrane protease serine subtype 2 at low levels on the cell surface under steady-state and inflammatory conditions. We did not observe SARS-CoV-2 infection or replication in MSCs at steady state under inflammatory conditions, or in direct contact with SARS-CoV-2-infected Caco-2 cells. Further, indoleamine 2,3-dioxygenase 1 production in MSCs was not impaired in the presence of SARS-CoV-2. We show that MSCs are resistant to SARS-CoV-2 infection and retain their immunomodulation potential, supporting their potential applicability for COVID-19 treatment.

Studies on the effects of bone marrow stem cells on mitochondrial function and the alleviation of ARDS

Mesenchymal stem cells (MSCs) can alleviate acute respiratory distress syndrome (ARDS), but the mechanisms involved are unclear, especially about their specific effects on cellular mitochondrial respiratory function. Thirty mice were allocated into the Control, LPS, and LPS + Bone marrow mesenchymal stem cell (BMSC) group (n = 10/group). Mouse alveolar epithelial cells (MLE-12) and macrophage cells (RAW264.7) were divided into the same groups. Pathological variation, inflammation-related factors, reactive oxygen species (ROS), ATP levels, and oxygen consumption rate (OCR) were analyzed. Pathologic features of ARDS were observed in the LPS group and were significantly alleviated by BMSCs. The trend in inflammation-related factors among the three groups was the LPS group > LPS + BMSC group > Control group. In the MLE-12 co-culture system, IL-6 was increased in the LPS group but not significantly reduced in the LPS + BMSC group. In the RAW264.7 co-culture system, IL-1β, TNF-α, and IL-10 levels were all increased in the LPS group, IL-1β and TNF-α levels were reduced by BMSCs, while IL-10 level kept increasing. ROS and ATP levels were increased and decreased respectively in both MLE-12 and RAW264.7 cells in the LPS groups but reversed by BMSCs. Basal OCR, ATP-linked OCR, and maximal OCR were lower in the LPS groups. Impaired basal OCR and ATP-linked OCR in MLE-12 cells were partially restored by BMSCs, while impaired basal OCR and maximal OCR in RAW264.7 cells were restored by BMSCs. BMSCs improved the mitochondrial respiration dysfunction of macrophages and alveolar epithelial cells induced by LPS, alleviated lung tissue injury, and inflammatory response in a mouse model of ARDS.

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.

Mesenchymal Stem/Stromal Cells Therapy for Sepsis and Acute Respiratory Distress Syndrome

Sepsis and acute respiratory distress syndrome (ARDS) constitute devastating conditions with high morbidity and mortality. Sepsis results from abnormal host immune response, with evidence for both pro- and anti-inflammatory activation present from the earliest phases. The "proinflammatory" response predominates initially causing host injury, with later-phase sepsis characterized by immune cell hypofunction and opportunistic superinfection. ARDS is characterized by inflammation and disruption of the alveolar-capillary membrane leading to injury and lung dysfunction. Sepsis is the most common cause of ARDS. Approximately 20% of deaths worldwide in 2017 were due to sepsis, while ARDS occurs in over 10% of all intensive care unit patients and results in a mortality of 30 to 45%. Given the fact that sepsis and ARDS share some-but not all-underlying pathophysiologic injury mechanisms, the lack of specific therapies, and their frequent coexistence in the critically ill, it makes sense to consider therapies for both conditions together. In this article, we will focus on the therapeutic potential of mesenchymal stem/stromal cells (MSCs). MSCs are available from several tissues, including bone marrow, umbilical cord, and adipose tissue. Allogeneic administration is feasible, an important advantage for acute conditions like sepsis or ARDS. They possess diverse mechanisms of action of relevance to sepsis and ARDS, including direct and indirect antibacterial actions, potent effects on the innate and adaptive response, and pro-reparative effects. MSCs can be preactivated thereby potentiating their effects, while the use of their extracellular vesicles can avoid whole cell administration. While early-phase clinical trials suggest safety, considerable challenges exist in moving forward to phase III efficacy studies, and to implementation as a therapy should they prove effective.

Umbilical Cord-derived Mesenchymal Stem Cells for COVID-19 Patients with Acute Respiratory Distress Syndrome (ARDS)

The coronavirus SARS-CoV-2 is cause of a global pandemic of a pneumonia-like disease termed Coronavirus Disease 2019 (COVID-19). COVID-19 presents a high mortality rate, estimated at 3.4%. More than 1 out of 4 hospitalized COVID-19 patients require admission to an Intensive Care Unit (ICU) for respiratory support, and a large proportion of these ICU-COVID-19 patients, between 17% and 46%, have died. In these patients COVID-19 infection causes an inflammatory response in the lungs that can progress to inflammation with cytokine storm, Acute Lung Injury (ALI), Acute Respiratory Distress Syndrome (ARDS), thromboembolic events, disseminated intravascular coagulation, organ failure, and death. Mesenchymal Stem Cells (MSCs) are potent immunomodulatory cells that recognize sites of injury, limit effector T cell reactions, and positively modulate regulatory cell populations. MSCs also stimulate local tissue regeneration via paracrine effects inducing angiogenic, anti-fibrotic and remodeling responses. MSCs can be derived in large number from the Umbilical Cord (UC). UC-MSCs, utilized in the allogeneic setting, have demonstrated safety and efficacy in clinical trials for a number of disease conditions including inflammatory and immune-based diseases. UC-MSCs have been shown to inhibit inflammation and fibrosis in the lungs and have been utilized to treat patients with severe COVID-19 in pilot, uncontrolled clinical trials, that reported promising results. UC-MSCs processed at our facility have been authorized by the FDA for clinical trials in patients with an Alzheimer's Disease, and in patients with Type 1 Diabetes (T1D). We hypothesize that UC-MSC will also exert beneficial therapeutic effects in COVID-19 patients with cytokine storm and ARDS. We propose an early phase controlled, randomized clinical trial in COVID-19 patients with ALI/ARDS. Subjects in the treatment group will be treated with two doses of UC-MSC (l00 × 10⁶ cells). The first dose will be infused within 24 hours following study enrollment. A second dose will be administered 72 ± 6 hours after the first infusion. Subject in the control group will receive infusion of vehicle (DPBS supplemented with 1% HSA and 70 U/kg unfractionated Heparin, delivered IV) following the same timeline. Subjects will be evaluated daily during the first 6 days, then at 14, 28, 60, and 90 days following enrollment (see Schedule of Assessment for time window details). Safety will be determined by adverse events (AEs) and serious adverse events (SAEs) during the follow-up period. Efficacy will be defined by clinical outcomes, as well as a variety of pulmonary, biochemical and immunological tests. Success of the current study will provide a framework for larger controlled, randomized clinical trials and a means of accelerating a possible solution for this urgent but unmet medical need. The proposed early phase clinical trial will be performed at the University of Miami (UM), in the facilities of the Diabetes Research Institute (DRI), UHealth Intensive Care Unit (ICU) and the Clinical Translational Research Site (CTRS) at the University of Miami Miller School of Medicine and at the Jackson Memorial Hospital (JMH).

Safety and efficacy of intrarenal arterial autologous CD34+ cell transfusion in patients with chronic kidney disease: A randomized, open-label, controlled phase II clinical trial

Background

This was a randomized, open‐label, controlled phase II clinical trial to investigate the safety, efficacy, and outcomes of intrarenal artery infusion of autologous peripheral‐blood‐derived CD34+ cells for patients with chronic kidney disease (CKD; ie, stage III or IV).

Materials and Methods

Between October 2016 and July 2018, 52 consecutive patients with CKD at stage III or IV were randomly allocated into a treatment group (TG; 2.5 × 10⁷ cells for each intrarenal artery; n = 26) and a control group (CG; standardized pharmacotherapy only; n = 26). The primary endpoints included safety and change of creatinine level/creatinine clearance. The secondary endpoints were 12‐month combined unfavorable clinical outcomes (defined as dialysis or death), improvement in proteinuria, and CD34+ cell‐related adverse events.

Results

All patients were uneventfully discharged after CD34+ cell therapy. The baseline endothelial progenitor cell (EPC) populations did not differ between TG and CG (P > .5). Flow cytometric analysis showed increases in circulating EPC (ie, CD34+KDR+CD45^dim/ CD34+CD133+CD45^dim/CD31+CD133+CD45^dim/CD34+CD133+KDR+/CD133+) and hematopoietic stem cell (CD34+) populations after granulocyte‐colony stimulating factor treatment (all P < .001). Besides, Matrigel assay of angiogenesis was also significantly enhanced (all P < .001). Renal‐venous blood samplings (ie, at 0, 5, 10, and 30 minutes after CD34+ cell infusion) demonstrated significant progressive increases in EPC level (P for trend <.001) among the TG patients. One‐year combined unfavorable clinical outcomes were significantly lower in TG than those in CG (0% [0] vs 13.3% [4], P = .038). By 12 months after CD34+ cell therapy, circulating creatinine level, ratio of urine protein to urine creatinine, and creatinine clearance showed no difference between TG and CG (all P > .1).

Conclusion

CD34+ cell therapy was safe and improved 1‐year outcome.

Mesenchymal stem cells induce dendritic cell immune tolerance via paracrine hepatocyte growth factor to alleviate acute lung injury

BACKGROUND

Mesenchymal stem cells (MSCs) have been shown to alleviate acute lung injury (ALI) via paracrine hepatocyte growth factor (HGF) and to induce the differentiation of dendritic cells (DCs) into tolerogenic dendritic cells (DCregs) and participate in the immune response. However, whether MSCs induce the production of DCregs by secreting HGF to alleviate early ALI remains unclear. We observed that the protective effect of mouse bone marrow-derived MSCs against lipopolysaccharide (LPS)-induced ALI was achieved by inducing mature DCs (mDCs) to differentiate into DCregs, and its mechanism is related to the activation of the HGF/Akt pathway.

METHODS

MSCs or MSCs with overexpression or knockdown of HGF were cocultured with DCs derived from mouse bone marrow using a Transwell system for 3 days. Moreover, we used MSCs or MSCs with overexpression or knockdown of HGF to treat LPS-induced ALI mice for 24 h. Flow cytometry was performed to measure the phagocytosis, accumulation, and maturation of DCs, as well as proliferation of T cells. Lung injury was estimated by lung wet weight to body weight ratio (LWW/BW) and histopathological analysis. Furthermore, we used the Akt inhibitor MK-2206 in a coculture system to elucidate the role of the HGF/Akt pathway in regulating the differentiation of DCs into regulatory DCs and relieving lung injury in early ALI mice.

RESULTS

Immature DCs (imDCs) were induced to mature after 24 h of LPS (50 ng/ml) stimulation. MSCs or HGF induced the differentiation of mDCs into regulatory DCs characterized by low expression of MHCII, CD86, and CD40 molecules, strong phagocytic function, and the ability to inhibit T cell proliferation. The effect of MSCs on DCregs was enhanced with the increase in HGF secretion and was weakened with the decrease in HGF secretion. DCregs induced by recombinant HGF were attenuated by the Akt inhibitor MK-2206. Lung DC aggregation and mDC ratio increased in LPS-induced ALI mice, while treatment with MSCs decreased lung DC aggregation and maturation and alleviated lung pathological injury. High expression of the HGF gene enhanced the above effect of MSCs, while decreased expression of HGF weakened the above effect of MSCs.

CONCLUSIONS

MSCs alleviate early ALI via paracrine HGF by inducing mDCs to differentiate into regulatory DCs. Furthermore, the mechanism of HGF-induced differentiation of mDCs into DCregs is related to the activation of the Akt pathway.

Mesenchymal stem cells significantly improved treatment effects of Linezolid on severe pneumonia in a rabbit model

The present study aimed to investigate whether co-administration of mesenchymal stromal cells (MSC) and linezolid (LZD) into a rabbit model of methicillin-resistant Staphylococcus aureus (MRSA)-infected pneumonia would bring a synergistic therapeutic effect. Human umbilical cord-derived MSCs (hUMSCs) were isolated and characterized. A rabbit model of pneumonia was constructed by delivering 1 × 1010 CFU MRSA via a bronchoscope into the basal segment of lower lobe of right lung. Through analyzing vital sign, pulmonary auscultation, SpO2, chest imaging, bronchoscopic manifestations, pathology, neutrophil percentage, and inflammatory factors, we verified that a rabbit model of MRSA-induced pneumonia was successfully constructed. Individual treatment with LZD (50 mg/kg for two times/day) resulted in improvement of body weight, chest imaging, bronchoscopic manifestations, histological parameters, and IL-10 concentration in plasma (P<0.01), decreasing pulmonary auscultation, and reduction of IL-8, IL-6, CRP, and TNF-α concentrations in plasma (P<0.01) compared with the pneumonia model group at 48 and 168 h. Compared with LZD group, co-administration of hUMSCs (1 × 106/kg for two times at 6 and 72 h after MRSA instillation) and LZD further increased the body weight (P<0.05). The changes we observed from chest imaging, bronchoscopic manifestations and pathology revealed that co-administration of hUMSCs and LZD reduced lung inflammation more significantly than that of LZD group. The plasma levels of IL-8, IL-6, CRP, and TNF-α in combined group decreased dramatically compared with the LZD group (P<0.05). In conclusion, hUMSCs administration significantly improved therapeutic effects of LZD on pneumonia resulted from MRSA infection in a rabbit model.

Human induced pluripotent stem cell-derived mesenchymal stem cell therapy effectively reduced brain infarct volume and preserved neurological function in rat after acute intracranial hemorrhage

We tested the hypothesis that human induced pluripotent stem cell-derived mesenchymal stem cell (iPSC-MSC) therapy could effectively reduce brain-infarct volume (BIV) and improve neurological function in rat after acute intracranial hemorrhage (ICH) induced by a weight-drop device. Adult-male SD rats (n=40) were equally divided into group 1 (sham-operated control), group 2 (ICH), group 3 (ICH + hyaluronic acid (HA)/intracranial injection at 3 h after ICH), group 4 [ICH + HA + iPSC-MSC (1.2 × 10⁶ cells/intracranial injection at 3 h after ICH)] and euthanized by day 28 after ICH procedure. In vitro study showed that hemorrhagic-brain tissue augmented protein expressions of inflammation (HMGB1/MyD88/TLR-4/TLR-2/NF-κB/TNF-α/iNOS/IL-1β) in cultured neurons that were significantly inhibited by iPSC-MSC treatment (all P<0.001). By days 7 and 14 after ICH procedure, circulating inflammatory levels of TNF-α/IL-6/MPO expressed were lowest in group 1, highest in group 2 and significantly lower in group 4 than in group 3 (all P<0.0001). By day 14 after ICH procedure, neurological function and BIV expressed an opposite pattern, whereas protein expressions of inflammation (HMGB1/MyD88/TLR-4/TLR-2/NF-κB/I-kB/TNF-α/iNOS/IL-1β/MMP-9), oxidative stress (NOX-1/NOX-2/oxidized protein) and apoptosis (mitochondrial-Bax/cleaved-caspase-2/PARP) in brain exhibited an identical pattern to circulating inflammation among the four groups (all P<0.001). Microscopy demonstrated that the number of vascular remodeling and GFAP+/53BP1+/γ-H2AX+ cells displayed an identical pattern of inflammation, whereas the NeuN+ cells displayed an opposite pattern of inflammation among the four groups (all P<0.001). In conclusion, iPSC-MSC therapy markedly reduced BIV and preserved neurological function mainly by inhibiting inflammatory/oxidative-stress generation.

Modeling trauma in rats: similarities to humans and potential pitfalls to consider

Trauma is the leading cause of mortality in humans below the age of 40. Patients injured by accidents frequently suffer severe multiple trauma, which is life-threatening and leads to death in many cases. In multiply injured patients, thoracic trauma constitutes the third most common cause of mortality after abdominal injury and head trauma. Furthermore, 40-50% of all trauma-related deaths within the first 48 h after hospital admission result from uncontrolled hemorrhage. Physical trauma and hemorrhage are frequently associated with complex pathophysiological and immunological responses. To develop a greater understanding of the mechanisms of single and/or multiple trauma, reliable and reproducible animal models, fulfilling the ethical 3 R's criteria (Replacement, Reduction and Refinement), established by Russell and Burch in 'The Principles of Human Experimental Technique' (published 1959), are required. These should reflect both the complex pathophysiological and the immunological alterations induced by trauma, with the objective to translate the findings to the human situation, providing new clinical treatment approaches for patients affected by severe trauma. Small animal models are the most frequently used in trauma research. Rattus norvegicus was the first mammalian species domesticated for scientific research, dating back to 1830. To date, there exist numerous well-established procedures to mimic different forms of injury patterns in rats, animals that are uncomplicated in handling and housing. Nevertheless, there are some physiological and genetic differences between humans and rats, which should be carefully considered when rats are chosen as a model organism. The aim of this review is to illustrate the advantages as well as the disadvantages of rat models, which should be considered in trauma research when selecting an appropriate in vivo model. Being the most common and important models in trauma research, this review focuses on hemorrhagic shock, blunt chest trauma, bone fracture, skin and soft-tissue trauma, burns, traumatic brain injury and polytrauma.

Current understanding of the therapeutic benefits of mesenchymal stem cells in acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) is a multifaceted lung disorder in which no specific therapeutic intervention is able to effectively improve clinical outcomes. Despite an improved understanding of molecular mechanisms and advances in supportive care strategies, ARDS remains associated with high mortality, and survivors usually face long-term morbidity. In recent years, preclinical studies have provided mounting evidence of the potential of mesenchymal stem cell (MSC)-based therapies in lung diseases and critical illnesses. In several models of ARDS, MSCs have been demonstrated to induce anti-inflammatory and anti-apoptotic effects, improve epithelial and endothelial cell recovery, and enhance microbial and alveolar fluid clearance, thus resulting in improved lung and distal organ function and survival. Early-stage clinical trials have also demonstrated the safety of MSC administration in patients with ARDS, but further, large-scale investigations are required to assess the safety and efficacy profile of these therapies. In this review, we summarize the main mechanisms whereby MSCs have been shown to exert therapeutic effects in experimental ARDS. We also highlight questions that need to be further elucidated and barriers that must be overcome in order to efficiently translate MSC research into clinical practice.

Eicosapentaenoic acid potentiates the therapeutic effects of adipose tissue-derived mesenchymal stromal cells on lung and distal organ injury in experimental sepsis

Background

Even though mesenchymal stromal cells (MSCs) mitigate lung and distal organ damage in experimental polymicrobial sepsis, mortality remains high. We investigated whether preconditioning with eicosapentaenoic acid (EPA) would potentiate MSC actions in experimental sepsis by further decreasing lung and distal organ injury, thereby improving survival.

Methods

In C57BL/6 mice, sepsis was induced by cecal hligation and puncture (CLP); sham-operated animals were used as control. Twenty-four hours after surgery, CLP mice were further randomized to receive saline, adipose tissue-derived (AD)-MSCs (10⁵, nonpreconditioned), or AD-MSCs preconditioned with EPA for 6 h (10⁵, EPA-preconditioned MSCs) intravenously. After 24 h, survival rate, sepsis severity score, lung mechanics and histology, protein level of selected biomarkers in lung tissue, cellularity in blood, distal organ damage, and MSC distribution (by technetium-99m tagging) were analyzed. Additionally, the effects of EPA on the secretion of resolvin-D₁ (RvD₁), prostaglandin E₂ (PGE₂), interleukin (IL)-10, and transforming growth factor (TGF)-β1 by MSCs were evaluated in vitro.

Results

Nonpreconditioned and EPA-preconditioned AD-MSCs exhibited similar viability and differentiation capacity, accumulated mainly in the lungs and kidneys following systemic administration. Compared to nonpreconditioned AD-MSCs, EPA-preconditioned AD-MSCs further reduced static lung elastance, alveolar collapse, interstitial edema, alveolar septal inflammation, collagen fiber content, neutrophil cell count as well as protein levels of interleukin-1β and keratinocyte chemoattractant in lung tissue, and morphological abnormalities in the heart (cardiac myocyte architecture), liver (hepatocyte disarrangement and Kupffer cell hyperplasia), kidney (acute tubular necrosis), spleen (increased number of megakaryocytes and lymphocytes), and small bowel (villi architecture disorganization). EPA preconditioning of MSCs resulted in increased secretion of pro-resolution and anti-inflammatory mediators (RvD₁, PGE₂, IL-10, and TGF-β).

Conclusions

Compared to nonpreconditioned cells, EPA-preconditioned AD-MSCs yielded further reductions in the lung and distal organ injury, resulting in greater improvement in sepsis severity score and higher survival rate in CLP-induced experimental sepsis. This may be a promising therapeutic approach to improve outcome in septic patients.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1365-z) contains supplementary material, which is available to authorized users.

Mesenchymal Stromal Cells Anno 2019: Dawn of the Therapeutic Era? Concise Review

2018 was the year of the first marketing authorization of an allogeneic stem cell therapy by the European Medicines Agency. The authorization concerns the use of allogeneic adipose tissue-derived mesenchymal stromal cells (MSCs) for treatment of complex perianal fistulas in Crohn's disease. This is a breakthrough in the field of MSC therapy. The last few years have, furthermore, seen some breakthroughs in the investigations into the mechanisms of action of MSC therapy. Although the therapeutic effects of MSCs have largely been attributed to their secretion of immunomodulatory and regenerative factors, it has now become clear that some of the effects are mediated through host phagocytic cells that clear administered MSCs and in the process adapt an immunoregulatory and regeneration supporting function. The increased interest in therapeutic use of MSCs and the ongoing elucidation of the mechanisms of action of MSCs are promising indicators that 2019 may be the dawn of the therapeutic era of MSCs and that there will be revived interest in research to more efficient, practical, and sustainable MSC-based therapies. Stem Cells Translational Medicine 2019;8:1126-1134.

Shock Wave Therapy Enhances Mitochondrial Delivery into Target Cells and Protects against Acute Respiratory Distress Syndrome

This study tested the hypothesis that shock wave therapy (SW) enhances mitochondrial uptake into the lung epithelial and parenchymal cells to attenuate lung injury from acute respiratory distress syndrome (ARDS). ARDS was induced in rats through continuous inhalation of 100% oxygen for 48 h, while SW entailed application 0.15 mJ/mm² for 200 impulses at 6 Hz per left/right lung field. In vitro and ex vivo studies showed that SW enhances mitochondrial uptake into lung epithelial and parenchyma cells (all p < 0.001). Flow cytometry demonstrated that albumin levels and numbers of inflammatory cells (Ly6G+/CD14+/CD68+/CD11^b/c+) in bronchoalveolar lavage fluid were the highest in untreated ARDS, were progressively reduced across SW, Mito, and SW + Mito (all p < 0.0001), and were the lowest in sham controls. The same profile was also seen for fibrosis/collagen deposition, levels of biomarkers of oxidative stress (NOX-1/NOX-2/oxidized protein), inflammation (MMP-9/TNF-α/NF-κB/IL-1β/ICAM-1), apoptosis (cleaved caspase 3/PARP), fibrosis (Smad3/TGF-β), mitochondrial damage (cytosolic cytochrome c) (all p < 0.0001), and DNA damage (γ-H2AX+), and numbers of parenchymal inflammatory cells (CD11+/CD14+/CD40L+/F4/80+) (p < 0.0001). These results suggest that SW-assisted Mito therapy effectively protects the lung parenchyma from ARDS-induced injury.

Cell therapy in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is driven by a severe pro-inflammatory response resulting in lung damage, impaired gas exchange and severe respiratory failure. There is no specific treatment that effectively improves outcome in ARDS. However, in recent years, cell therapy has shown great promise in preclinical ARDS studies. A wide range of cells have been identified as potential candidates for use, among these are mesenchymal stromal cells (MSCs), which are adult multi-lineage cells that can modulate the immune response and enhance repair of damaged tissue. The therapeutic potential of MSC therapy for sepsis and ARDS has been demonstrated in multiple in vivo models. The therapeutic effect of these cells seems to be due to two different mechanisms; direct cellular interaction, and paracrine release of different soluble products such as extracellular vesicles (EVs)/exosomes. Different approaches have also been studied to enhance the therapeutic effect of these cells, such as the over-expression of anti-inflammatory or pro-reparative molecules. Several clinical trials (phase I and II) have already shown safety of MSCs in ARDS and other diseases. However, several translational issues still need to be addressed, such as the large-scale production of cells, and their potentiality and variability, before the therapeutic potential of stem cells therapies can be realized.