Comparison of Single and Repeated Dosing of Anti-Inflammatory Human Umbilical Cord Mesenchymal Stromal Cells in a Mouse Model of Polymicrobial Sepsis

PROTECTION OF MICE AGAINST CECAL LIGATION AND PUNCTURE-INDUCED POLYMICROBIAL SEPSIS BY A FASCIOLA HEPATICA HELMINTH DEFENSE MOLECULE

ABSTRACT

Sepsis results from a dysregulated host immune response to infection and is responsible for ~11 million deaths each year. In the laboratory, many aspects of sepsis can be replicated using a cecal ligation and puncture model, which is considered the most clinically relevant rodent model of sepsis. In the present study, histological and biomarker multiplex analyses revealed that the cecal ligation and puncture model initiated a large-scale inflammatory response in mice by 24 h, with evidence of acute organ damage by 48-72 h. While many typical proinflammatory cytokine/chemokines were systemically elevated, a specific array including IL-10, eotaxin, MIP-1α, MIP-1β, MCP-1, and RANTES noticeably increased just prior to animals reaching the humane endpoint. Treatment of mice with 10 μg of a synthetic 68-amino acid peptide derived from an immunomodulatory molecule secreted by a parasitic worm of humans and livestock, F. hepatica , termed F. hepatica helminth defense molecule, potently suppressed the systemic inflammatory profile, protected mice against acute kidney injury, and improved survival between 48 and 72 h after procedure. These results suggest that the anti-inflammatory parasite-derived F. hepatica helminth defense molecule peptide has potential as a biotherapeutic treatment for sepsis.

Tailoring cell therapies for diabetic metabolic phenotypes: a comparative study on the efficacy of various umbilical cord-derived cell regimens

Given the high heterogeneity of type 2 diabetes mellitus (T2DM), it is imperative to develop personalized stem cell infusion regimen for targeted metabolic phenotype in order to ensure optimal therapeutic efficacy. In this study, we conducted a comparative analysis of 4 infusion regimens involving single and repeated infusions of human umbilical cord Wharton's jelly-derived MSCs (hucMSCs), single infusions of umbilical cord blood mononuclear cells (UCB), and sequential infusions of hucMSCs and UCB in T2DM rats. Results showed all 4 infusion regimens exhibited comparable efficacy in lowering fasting blood glucose levels and suppressing glucagon secretion. Single and double infusions of hucMSCs exhibited a tendency to migrate to the liver, thereby better at ameliorating hepatic glucose metabolism by enhancing glycogen synthesis and storage, promoting glycolysis, inhibiting gluconeogenesis, and improving insulin signal transduction. The sequential infusion of hucMSCs and UCB demonstrated specific cell tropism toward the pancreas, leading to prolonged glucose-lowering effects following a glucose tolerance test, restoration of early-phase insulin secretion, stimulation of islet beta cell proliferation and improvement in the beta/alpha ratio. Multiple injections, regardless of cell type, reduced the expression of systemic chronic inflammatory markers such as IL-1β, IL-6, IL-17, IL-22, and IFN-γ. Finally, a single dose of UCB exhibited a greater tendency to target visceral fat and enhanced effectiveness in regulating levels of total cholesterol and triglycerides. In conclusion, our study provided personalized stem cell regimens for diverse T2DM metabolic phenotypes, thereby offering improved treatment alternatives for future clinical trials and applications.

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.

Effect of in vivo culture conditions on the proliferation and differentiation of rat adipose-derived stromal cells

Adipose-derived stromal cells (ADSCs) are promising stem cell sources for tissue engineering and cell-based therapy. However, long-term in vitro expansion of ADSCs impedes stemness maintenance, which is partly attributed to deprivation of their original microenvironment. Incompetent cells limit the therapeutic effects of ADSC-based clinical strategies. Therefore, reconstructing a more physiologically and physically relevant niche is an ideal strategy to address this issue and therefore facilitates the extensive application of ADSCs. Here, we transplanted separated ADSCs into local subcutaneous adipose tissues of nude mice as an in vivo cell culture model. We found that transplanted ADSCs maintained their primitive morphology and showed improved proliferation and delayed senescence compared to those of cells cultured in an incubator. Significantly increased expression of stemness-related markers and multilineage differentiation abilities were further observed in in vivo cultured ADSCs. Finally, sequencing revealed that genes whose expression differed between ADSCs obtained under in vivo and in vitro conditions were mainly located in the extracellular matrix and extracellular space and that these genes participate in regulating transcription and protein synthesis. Moreover, we found that an Egr1 signaling pathway might exert a crucial impact on controlling stemness properties. Our findings might collectively pave the way for ADSC-based applications.

Repeat intramuscular transplantation of human dental pulp stromal cells is more effective in sustaining Schwann cell survival and myelination for functional recovery after onset of diabetic neuropathy

BACKGROUND AIMS

Mesenchymal stromal cell (MSC) therapy for diabetic neuropathy (DN) has been extensively researched in vitro and in pre-clinical studies; however, the clinical scenario thus far has been disappointing. Temporary recovery, a common feature of these studies, indicates that either the retention of transplanted cells deteriorates with time or recovery of supportive endogenous cells, such as bone marrow-derived MSCs (BM-MSCs), does not occur, requiring further replenishment. In DN, BM-MSCs are recognized mediators of Schwann cell regeneration, and we have earlier shown that they suffer impairment in the pre-neuropathy stage. In this study, we attempted to further elucidate the mechanisms of functional recovery by focusing on changes occurring at the cellular level in the sciatic nerve, in conjunction with the biodistribution and movement patterns of the transplanted cells, to define the interval between doses.

METHOD & RESULTS

We found that two doses of 1 × 106 dental pulp stromal cells (DPSCs) transplanted intramuscularly at an interval of 4 weeks effectively improved nerve conduction velocity (NCV) and restored motor coordination through improving sciatic nerve architecture, Schwann cell survival and myelination. Despite very minimal recovery of endogenous BM-MSCs, a temporary restoration of NCV and motor function was achieved with the first dose of DPSC transplantation. However, this did not persist, and a repeat dose was needed to consolidate functional improvement and rehabilitate the sciatic nerve architecture.

CONCLUSION

Thus, repeat intramuscular transplantation of DPSCs is more effective for maintenance of Schwann cell survival and myelination for functional recovery after onset of DN.

The efficacy of mesenchymal stem cell treatment and colistin-fosfomycin combination on colistin-resistant Acinetobacter baumannii sepsis model

INTRODUCTION

This study examines the role of mesenchymal stem cells (MSCs) in an experimental sepsis model developed with colistin-resistant Acinetobacter baumannii (CRAB).

MATERIALS AND METHODS

BALB-c mice were divided into treatment groups (MSC, MSC + colistin (C)-fosfomycin (F), and C-F and control groups (positive and negative)). CRAB was administered to mice through intraperitoneal injection. Three hours later, C, F, and MSC were given intraperitoneally to the treatment groups. Colistin administration was repeated every 12 h, F administration was done every 4 h, and the second dose of MSC was administered after 48 h. Mice were sacrificed at 24 and 72 h. The bacterial load was determined as colony-forming units per gram (cfu/g). Histopathological examination was conducted on the left lung, liver, and both kidneys. IL-6 and C-reactive protein (CRP) levels in mouse sera were determined by enzyme-linked immunosorbent assay.

RESULTS

Among the treatment groups, the C-F group had the lowest colony count in the lung (1.24 ± 1.66 cfu/g) and liver (1.03 ± 1.08 cfu/g). The highest bacterial clearance was observed at 72 h compared to 24 h in the MSC-treated groups (p = 0.008). The MSC + C-F group showed the lowest histopathological score in the liver and kidney (p = 0.009). In the negative control group, the IL-6 level at the 24th hour was the lowest (p < 0.001). Among the treatment groups, the CRP level was the lowest in the MSC + C-F group at 24 and 72 h.

CONCLUSION

In a CRAB sepsis model, adding MSCs to a colistin-fosfomycin treatment may be beneficial in terms of reducing bacterial loads and preventing histopathological damage.

TREATMENT WITH HUMAN UMBILICAL CORD-DERIVED MESENCHYMAL STEM CELLS IN A PIG MODEL OF SEPSIS-INDUCED ACUTE KIDNEY INJURY: EFFECTS ON MICROVASCULAR ENDOTHELIAL CELLS AND TUBULAR CELLS IN THE KIDNEY

ABSTRACT

Background: Approximately 50% of patients with sepsis develop acute kidney injury (AKI), which is predictive of poor outcomes, with mortality rates of up to 70%. The endothelium is a major target for treatments aimed at preventing the complications of sepsis. We hypothesized that human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) could attenuate tubular and endothelial injury in a porcine model of sepsis-induced AKI. Methods: Anesthetized pigs were induced to fecal peritonitis, resulting in septic shock, and were randomized to treatment with fluids, vasopressors, and antibiotics (sepsis group; n = 11) or to that same treatment plus infusion of 1 × 10 6 cells/kg of hUC-MSCs (sepsis+MSC group; n = 11). Results: At 24 h after sepsis induction, changes in serum creatinine and mean arterial pressure were comparable between the two groups, as was mortality. However, the sepsis+MSC group showed some significant differences in comparison with the sepsis group: lower fractional excretions of sodium and potassium; greater epithelial sodium channel protein expression; and lower protein expression of the Na-K-2Cl cotransporter and aquaporin 2 in the renal medulla. Expression of P-selectin, thrombomodulin, and vascular endothelial growth factor was significantly lower in the sepsis+MSC group than in the sepsis group, whereas that of Toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) was lower in the former. Conclusion: Treatment with hUC-MSCs seems to protect endothelial and tubular cells in sepsis-induced AKI, possibly via the TLR4/NF-κB signaling pathway. Therefore, it might be an effective treatment for sepsis-induced AKI.

The Effects of Programmed Cell Death of Mesenchymal Stem Cells on the Development of Liver Fibrosis

Mesenchymal stem cells have shown noticeable potential for unlimited self-renewal. They can differentiate into specific somatic cells, integrate into target tissues via cell-cell contact, paracrine effects, exosomes, and other processes and then regulate the target cells and tissues. Studies have demonstrated that transplantation of MSCs could decrease the expression and concentration of collagen in the liver, thereby reducing liver fibrosis. A growing body of evidence indicates that apoptotic MSCs could inhibit harmful immune responses and reduce inflammatory responses more effectively than viable MSCs. Accumulating evidence suggests that mitochondrial transfer from MSCs is a novel strategy for the regeneration of various damaged cells via the rescue of their respiratory activities. This study is aimed at reviewing the functions of MSCs and the related roles of the programmed cell death of MSCs, including autophagy, apoptosis, pyroptosis, and ferroptosis, as well as the regulatory pathogenic mechanisms of MSCs in liver fibrosis. Research has demonstrated that the miR-200B-3p gene is differentially expressed gene between LF and normal liver samples, and that the miR-200B-3p gene expression is positively correlated with the degree of liver fibrosis, suggesting that MSCs could inhibit liver fibrosis through pyroptosis. It was confirmed that circulating monocytes could deliver MSC-derived immunomodulatory molecules to different sites by phagocytosis of apoptotic MSCs, thereby achieving systemic immunosuppression. Accordingly, it was suggested that characterization of the programmed cell death-mediated immunomodulatory signaling pathways in MSCs should be a focus of research.

Long-Term Effects of Severe Burns on the Kidneys: Research Advances and Potential Therapeutic Approaches

Burns are a seriously underestimated form of trauma that not only damage the skin system but also cause various complications, such as acute kidney injury (AKI). Recent clinical studies have shown that the proportion of chronic kidney diseases (CKD) in burn patients after discharge is significantly higher than that in the general population, but the mechanism behind this is controversial. The traditional view is that CKD is associated with hypoperfusion, AKI, sepsis, and drugs administered in the early stages of burns. However, recent studies have shown that burns can cause long-term immune dysfunction, which is a high-risk factor for CKD. This suggests that burns affect the kidneys more than previously recognized. In other words, severe burns are not only an acute injury but also a chronic disease. Neglecting to study long-term kidney function in burn patients also results in a lack of preventive and therapeutic methods being developed. Furthermore, stem cells and their exosomes have shown excellent comprehensive therapeutic properties in the prevention and treatment of CKD, making them increasingly the focus of research attention. Their engineering strategy further improved the therapeutic performance. This review will focus on the research advances in burns on the development of CKD, illustrating the possible mechanism of burn-induced CKD and introducing potential biological treatment options and their engineering strategies.

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

ABSTRACT

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

Improving the immunomodulatory function of mesenchymal stem cells by defined chemical approach

Mesenchymal stem cell (MSC) is a potential therapeutic material that has self-renewal, multilineage differentiation, and immunomodulation properties. However, the biological function of MSCs may decline due to the influence of donor differences and the in vitro expansion environment, which hinders the advancement of MSC-based clinical therapy. Here, we investigated a method for improving the immunomodulatory function of MSCs with the help of small-molecule compounds, A-83-01, CHIR99021, and Y27632 (ACY). The results showed that small-molecule induced MSCs (SM-MSCs) could enhance their immunosuppressive effects on T cells and macrophages. In vivo studies showed that, in contrast to control MSCs (Ctrl-MSCs), SM-MSCs could inhibit the inflammatory response in mouse models of delayed hypersensitivity and acute peritonitis more effectively. In addition, SM-MSCs showed the stronger ability to inhibit the infiltration of pro-inflammatory T cells and macrophages. Thus, small-molecule compounds ACY could better promote the immunomodulatory effect of MSCs, indicating it could be a potential improving method in MSC culture.