Multiplex Analysis of Cytokines, Chemokines, Growth Factors, MMP-9 and TIMP-1 Produced by Human Bone Marrow, Adipose Tissue, and Placental Mesenchymal Stromal Cells

Revolutionizing bone defect healing: the power of mesenchymal stem cells as seeds

Bone defects can arise from trauma or pathological factors, resulting in compromised bone integrity and the loss or absence of bone tissue. As we are all aware, repairing bone defects is a core problem in bone tissue engineering. While minor bone defects can self-repair if the periosteum remains intact and normal osteogenesis occurs, significant defects or conditions such as congenital osteogenesis imperfecta present substantial challenges to self-healing. As research on mesenchymal stem cell (MSC) advances, new fields of application have emerged; however, their application in orthopedics remains one of the most established and clinically valuable directions. This review aims to provide a comprehensive overview of the research progress regarding MSCs in the treatment of diverse bone defects. MSCs, as multipotent stem cells, offer significant advantages due to their immunomodulatory properties and ability to undergo osteogenic differentiation. The review will encompass the characteristics of MSCs within the osteogenic microenvironment and summarize the research progress of MSCs in different types of bone defects, ranging from their fundamental characteristics and animal studies to clinical applications.

Escherichia coli induced matrix metalloproteinase-9 activity and type IV collagen degradation is regulated by progesterone in human maternal decidual

BACKGROUND

Escherichia coli (E. coli) is one of the main bacteria associated with preterm premature rupture of membranes by increasing pro-matrix metalloproteinase 9 (proMMP-9) and degradation of type IV collagen in human feto-maternal interface (HFMi). proMMP-9 is regulated by progesterone (P4) but it is unclear whether P4 inhibits proMMP in human maternal decidual (MDec). This study aimed to determine a role of P4 on proMMP-2 and - 9 and type IV collagen induced by E. coli infection in MDec.

METHODS

Nine HFMi were mounted in a Transwell system. MDec was stimulated with P4 or E. coli for 3-, 6-, or 24-hours. proMMP-2, -9 and type IV collagen were assessed.

RESULTS

Gelatin zymography revealed an increase in proMMP-9 after 3, 6, and 24 h of stimulating MDec with E. coli. Using immunofluorescence, it was confirmed the increase in the HFMi tissue and a reduction on the amount of type IV collagen leading to the separation of fetal amniochorion and MDEc. The degradative activity of proMMP-9 was reduced by 20% by coincubation with P4.

CONCLUSIONS

P4 modulates the activity of proMMP-9 induced by E. coli stimulation but it was unable to completely reverse the degradation of type IV collagen in human MDec tissue.

Unique Serum Immune Phenotypes and Stratification of Oklahoma Native American Rheumatic Disease Patients

OBJECTIVE

Native American (NA) populations have higher rates of rheumatic disease and present with overlapping disease symptoms and nontraditional serologic features, thus presenting an urgent need for better biomarkers in NA diagnostics. This study used a machine learning approach to identify immune signatures that more effectively stratify NA patients with rheumatic disease.

METHODS

Adult NA patients with autoantibody-positive (AAB+) rheumatoid arthritis (RA; n = 28), autoantibody negative (AAB-) RA (n = 18), systemic autoimmune rheumatic disease (n = 28), arthralgia/osteoarthritis (n = 28), or polyarthritis/undifferentiated connective tissue disease (n = 28), and control patients (n = 28) provided serum samples for cytokine, chemokine, and AAB assessment. Random forest clustering and soluble mediator groups were used to identify patients and control patients with similar biologic signatures. The American College of Rheumatology criteria specific for systemic disease and RA identified differences in disease manifestations across clusters.

RESULTS

Serum soluble mediators were not homogenous between different NA rheumatic disease diagnostic groups, reflecting the heterogeneity of autoimmune diseases. Clustering by serum biomarkers created 5 analogous immune phenotypes. Soluble mediators and pathways associated with chronic inflammation and involvement of the innate, B cell, T follicular helper cell, and interferon-associated pathways, along with regulatory signatures, distinguished the 5 immune signatures among patients. Select clinical features were associated with individual immune profiles. Patients with low inflammatory and higher regulatory signatures were more likely to have few clinical manifestations, whereas those with T cell pathway involvement had more arthritis.

CONCLUSION

Serum protein signatures distinguished NA patients with rheumatic disease into distinct immune subsets. Following these immune profiles over time may assist with earlier diagnoses and help guide more personalized treatment approaches.

Functional enhancement strategies to potentiate the therapeutic properties of mesenchymal stromal cells for respiratory diseases

Respiratory diseases remain a major health concern worldwide because they subject patients to considerable financial and psychosocial burdens and result in a high rate of morbidity and mortality. Although significant progress has been made in understanding the underlying pathologic mechanisms of severe respiratory diseases, most therapies are supportive, aiming to mitigate symptoms and slow down their progressive course but cannot improve lung function or reverse tissue remodeling. Mesenchymal stromal cells (MSCs) are at the forefront of the regenerative medicine field due to their unique biomedical potential in promoting immunomodulation, anti-inflammatory, anti-apoptotic and antimicrobial activities, and tissue repair in various experimental models. However, despite several years of preclinical research on MSCs, therapeutic outcomes have fallen far short in early-stage clinical trials for respiratory diseases. This limited efficacy has been associated with several factors, such as reduced MSC homing, survival, and infusion in the late course of lung disease. Accordingly, genetic engineering and preconditioning methods have emerged as functional enhancement strategies to potentiate the therapeutic actions of MSCs and thus achieve better clinical outcomes. This narrative review describes various strategies that have been investigated in the experimental setting to functionally potentiate the therapeutic properties of MSCs for respiratory diseases. These include changes in culture conditions, exposure of MSCs to inflammatory environments, pharmacological agents or other substances, and genetic manipulation for enhanced and sustained expression of genes of interest. Future directions and challenges in efficiently translating MSC research into clinical practice are discussed.

Micro-fragmented adipose tissue cellular composition varies by processing device and analytical method

Autologous adipose-derived biologics are of clinical interest based on accessibility of adipose tissue, a rich source of progenitor and immunomodulatory cells. Micro-fragmented adipose tissue (MFAT) preserves the cellular niche within intact extracellular matrix, potentially offering benefit over enzymatically-liberated stromal vascular fraction (SVF), however lack of standardized analyses complicate direct comparison of these products. In this study, MFAT from LipoGems® and AutoPose™ Restore systems, which utilize different washing and resizing methods, was analyzed for cellular content using different techniques. Flow cytometry was performed on SVF, with or without culture, and on the adherent cell population that naturally migrated from undigested MFAT. Cytokine release during culture was also assessed. SVF contained more diverse progenitor populations, while MFAT outgrowth contained lower cell concentrations of predominantly mesenchymal stromal cells (MSC). MSCs were significantly higher in MFAT from the AutoPose System for all analyses, with increased cytokine secretion characterized by high levels of anti-inflammatory and low to non-detectable inflammatory cytokines. These results demonstrate that cellularity depends on MFAT processing methods, and different techniques can be employed to evaluate graft cellularity. Comparisons of cell concentrations determined via these methods could be used to better interpret inter-study variability.

Stem Cell-Based Regenerative Therapy and Derived Products in COPD: A Systematic Review and Meta-Analysis

COPD is an incurable disorder, characterized by a progressive alveolar tissue destruction and defective mechanisms of repair and defense leading to emphysema. Currently, treatment for COPD is exclusively symptomatic; therefore, stem cell-based therapies represent a promising therapeutic approach to regenerate damaged structures of the respiratory system and restore lung function. The aim of this study was to provide a quantitative synthesis of the efficacy profile of stem cell-based regenerative therapies and derived products in COPD patients. A systematic review and meta-analysis was performed according to PRISMA-P. Data from 371 COPD patients were extracted from 11 studies. Active treatments elicited a strong tendency towards significance in FEV1 improvement (+71 mL 95% CI -2−145; p = 0.056) and significantly increased 6MWT (52 m 95% CI 18−87; p < 0.05) vs. baseline or control. Active treatments did not reduce the risk of hospitalization due to acute exacerbations (RR 0.77 95% CI 0.40−1.49; p > 0.05). This study suggests that stem cell-based regenerative therapies and derived products may be effective to treat COPD patients, but the current evidence comes from small clinical trials. Large and well-designed randomized controlled trials are needed to really quantify the beneficial impact of stem cell-based regenerative therapy and derived products in COPD.

A Role for the Bone Marrow Microenvironment in Drug Resistance of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease with a poor prognosis and remarkable resistance to chemotherapeutic agents. Understanding resistance mechanisms against currently available drugs helps to recognize the therapeutic obstacles. Various mechanisms of resistance to chemotherapy or targeted inhibitors have been described for AML cells, including a role for the bone marrow niche in both the initiation and persistence of the disease, and in drug resistance of the leukemic stem cell (LSC) population. The BM niche supports LSC survival through direct and indirect interactions among the stromal cells, hematopoietic stem/progenitor cells, and leukemic cells. Additionally, the BM niche mediates changes in metabolic and signal pathway activation due to the acquisition of new mutations or selection and expansion of a minor clone. This review briefly discusses the role of the BM microenvironment and metabolic pathways in resistance to therapy, as discovered through AML clinical studies or cell line and animal models.

Adipose Stem Cell-Based Clinical Strategy for Neural Regeneration: A Review of Current Opinion

Nerve injury is a critical problem in the clinic. Nerve injury causes serious clinic issues including pain and dysfunctions for patients. The disconnection between damaged neural fibers and muscles will result in muscle atrophy in a few weeks if no treatment is applied. Moreover, scientists have discovered that nerve injury can affect the osteogenic differentiation of skeletal stem cells (SSCs) and the fracture repairing. In plastic surgery, muscle atrophy and bone fracture after nerve injury have plagued clinicians for many years. How to promote neural regeneration is the core issue of research in the recent years. Without obvious effects of traditional neurosurgical treatments, research on stem cells in the past 10 years has provided a new therapeutic strategy for us to address this problem. Adipose stem cells (ASCs) are a kind of mesenchymal stem cells that have differentiation potential in adipose tissue. In the recent years, ASCs have become the focus of regenerative medicine. They play a pivotal role in tissue regeneration engineering. As a type of stem cell, ASCs are becoming popular for neuroregenerative medicine due to their advantages and characteristics. In the various diseases of the nervous system, ASCs are gradually applied to treat the related diseases. This review article focuses on the mechanism and clinical application of ASCs in nerve regeneration as well as the related research on ASCs over the past decades.

Preconditioning of Rat Bone Marrow-Derived Mesenchymal Stromal Cells with Toll-Like Receptor Agonists

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) are dynamic cells that can sense the environment, adapting their regulatory functions to different conditions. Accordingly, the therapeutic potential of BM-MSCs can be modulated by preconditioning strategies aimed at modifying their paracrine action. Although rat BM-MSCs (rBM-MSCs) have been widely tested in preclinical research, most preconditioning studies have employed human and mouse BM-MSCs. Herein, we investigated whether rBM-MSCs modify their phenotype and paracrine functions in response to Toll-like receptor (TLR) agonists. The data showed that rBM-MSCs expressed TLR3, TLR4, and MDA5 mRNA and were able to internalize polyinosinic-polycytidylic acid (Poly(I:C)), a TLR3/MDA5 agonist. rBM-MSCs were then stimulated with Poly(I:C) or with lipopolysaccharide (LPS, a TLR4 agonist) for 1 h and were grown under normal culture conditions. LPS or Poly(I:C) stimulation did not affect the viability or the morphology of rBM-MSCs and did not modify the expression pattern of key cell surface markers. Poly(I:C) did not induce statistically significant changes in the release of several inflammatory mediators and VEGF by rBM-MSCs, although it tended to increase IL-6 and MCP-1 secretion, whereas LPS increased the release of IL-6, MCP-1, and VEGF, three factors that were constitutively secreted by unstimulated cells. The neurotrophic activity of the conditioned medium from unstimulated and LPS-preconditioned rBM-MSCs was investigated using dorsal root ganglion explants, showing that soluble factors produced by unstimulated and LPS-preconditioned rBM-MSCs can stimulate neurite outgrowth similarly, in a VEGF-dependent manner. LPS-preconditioned cells, however, were slightly more efficient in increasing the number of regrowing axons in a model of sciatic nerve transection in rats. In conclusion, LPS preconditioning boosted the production of constitutively secreted factors by rBM-MSCs, without changing their mesenchymal identity, an effect that requires further investigation in exploratory preclinical studies.

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.

Mesenchymal Stem Cells From Bone Marrow, Adipose Tissue, and Lung Tissue Differentially Mitigate Lung and Distal Organ Damage in Experimental Acute Respiratory Distress Syndrome

OBJECTIVES

Mesenchymal stem cells-based therapies have shown promising effects in experimental acute respiratory distress syndrome. Different mesenchymal stem cells sources may result in diverse effects in respiratory diseases; however, there is no information regarding the best source of mesenchymal stem cells to treat pulmonary acute respiratory distress syndrome. We tested the hypothesis that mesenchymal stem cells derived from bone marrow, adipose tissue, and lung tissue would lead to different beneficial effects on lung and distal organ damage in experimental pulmonary acute respiratory distress syndrome.

DESIGN

Animal study and primary cell culture.

SETTING

Laboratory investigation.

SUBJECTS

Seventy-five Wistar rats.

INTERVENTIONS

Wistar rats received saline (control) or Escherichia coli lipopolysaccharide (acute respiratory distress syndrome) intratracheally. On day 2, acute respiratory distress syndrome animals were further randomized to receive saline or bone marrow, adipose tissue, or lung tissue mesenchymal stem cells (1 × 10 cells) IV. Lung mechanics, histology, and protein levels of inflammatory mediators and growth factors were analyzed 5 days after mesenchymal stem cells administration. RAW 264.7 cells (a macrophage cell line) were incubated with lipopolysaccharide followed by coculture or not with bone marrow, adipose tissue, and lung tissue mesenchymal stem cells (10 cells/mL medium).

MEASUREMENTS AND MAIN RESULTS

Regardless of mesenchymal stem cells source, cells administration improved lung function and reduced alveolar collapse, tissue cellularity, collagen, and elastic fiber content in lung tissue, as well as decreased apoptotic cell counts in liver. Bone marrow and adipose tissue mesenchymal stem cells administration also reduced levels of tumor necrosis factor-α, interleukin-1β, keratinocyte-derived chemokine, transforming growth factor-β, and vascular endothelial growth factor, as well as apoptotic cell counts in lung and kidney, while increasing expression of keratinocyte growth factor in lung tissue. Additionally, mesenchymal stem cells differently modulated the secretion of biomarkers by macrophages depending on their source.

CONCLUSIONS

Mesenchymal stem cells from different sources led to variable responses in lungs and distal organs. Bone marrow and adipose tissue mesenchymal stem cells yielded greater beneficial effects than lung tissue mesenchymal stem cells. These findings may be regarded as promising in clinical trials.

Concentrated Conditioned Media from Adipose Tissue Derived Mesenchymal Stem Cells Mitigates Visual Deficits and Retinal Inflammation Following Mild Traumatic Brain Injury

Blast concussions are a common injury sustained in military combat today. Inflammation due to microglial polarization can drive the development of visual defects following blast injuries. In this study, we assessed whether anti-inflammatory factors released by the mesenchymal stem cells derived from adipose tissue (adipose stem cells, ASC) can limit retinal tissue damage and improve visual function in a mouse model of visual deficits following mild traumatic brain injury. We show that intravitreal injection of 1 μL of ASC concentrated conditioned medium from cells pre-stimulated with inflammatory cytokines (ASC-CCM) mitigates loss of visual acuity and contrast sensitivity four weeks post blast injury. Moreover, blast mice showed increased retinal expression of genes associated with microglial activation and inflammation by molecular analyses, retinal glial fibrillary acidic protein (GFAP) immunoreactivity, and increased loss of ganglion cells. Interestingly, blast mice that received ASC-CCM improved in all parameters above. In vitro, ASC-CCM not only suppressed microglial activation but also protected against Tumor necrosis alpha (TNFα) induced endothelial permeability as measured by transendothelial electrical resistance. Biochemical and molecular analyses demonstrate TSG-6 is highly expressed in ASC-CCM from cells pre-stimulated with TNFα and IFNγ but not from unstimulated cells. Our findings suggest that ASC-CCM mitigates visual deficits of the blast injury through their anti-inflammatory properties on activated pro-inflammatory microglia and endothelial cells. A regenerative therapy for immediate delivery at the time of injury may provide a practical and cost-effective solution against the traumatic effects of blast injuries to the retina.

Can Youthful Mesenchymal Stem Cells from Wharton's Jelly Bring a Breath of Fresh Air for COPD?

Chronic obstructive pulmonary disease (COPD) is a major global cause of morbidity and mortality, projected to become the 3rd cause of disease mortality worldwide by 2020. COPD is characterized by persistent and not fully reversible airflow limitation that is usually progressive and is associated with an abnormal chronic inflammatory response of the lung to noxious agents including cigarette smoke. Currently available therapeutic strategies aim to ease COPD symptoms but cannot prevent its progress or regenerate physiological lung structure or function. The urgently needed new approaches for the treatment of COPD include stem cell therapies among which transplantation of mesenchymal stem cells derived from Wharton’s jelly (WJ-MSCs) emerges as a promising therapeutic strategy because of the unique properties of these cells. The present review discusses the main biological properties of WJ-MSCs pertinent to their potential application for the treatment of COPD in the context of COPD pathomechanisms with emphasis on chronic immune inflammatory processes that play key roles in the development and progression of COPD.

Corneal Mesenchymal Stromal Cells Are Directly Antiangiogenic via PEDF and sFLT-1

Purpose

To evaluate the angiogenic properties of corneal derived mesenchymal stromal cells (Co-MSC).

Methods

Co-MSCs were extracted from human cadaver, and wild-type (C57BL/6J) and SERPINF1^−/− mice corneas. The MSC secretome was collected in a serum-free medium. Human umbilical vein endothelial cell (HUVEC) tube formation and fibrin gel bead assay (FIBA) sprout formation were used to assess the angiogenic properties of Co-MSC secretome. Complete corneal epithelial debridement was used to induce corneal neovascularization in wild-type mice. Co-MSCs embedded in fibrin gel was applied over the debrided cornea to evaluate the angiogenic effects of Co-MSCs in vivo. Immunoprecipitation was used to remove soluble fms-like tyrosine kinase-1 (sFLT-1) and pigment epithelium-derived factor (PEDF, SERPINF1 gene) from the Co-MSC secretome.

Results

Co-MSC secretome significantly inhibited HUVECs tube and sprout formation. Co-MSCs from different donors consistently contained high levels of antiangiogenic factors including sFLT-1 and PEDF; and low levels of the angiogenic factor VEGF-A. In vivo, application of Co-MSCs to mouse corneas after injury prevented the development of corneal neovascularization. Removing PEDF or sFLT-1 from the secretome significantly diminished the antiangiogenic effects of Co-MSCs. Co-MSCs isolated from SERPINF1^−/− mice had significantly reduced antiangiogenic effects compared to SERPINF1^+/+ (wild-type) Co-MSCs.

Conclusions

These results illustrate the direct antiangiogenic properties of Co-MSCs, the importance of sFLT-1 and PEDF, and their potential clinical application for preventing pathologic corneal neovascularization.

Mesenchymal stromal cell therapy in COPD: from bench to bedside

COPD is the most frequent chronic respiratory disease and a leading cause of morbidity and mortality. The major risk factor for COPD development is cigarette smoke, and the most efficient treatment for COPD is smoking cessation. However, even after smoking cessation, inflammation, apoptosis, and oxidative stress may persist and continue contributing to disease progression. Although current therapies for COPD (primarily based on anti-inflammatory agents) contribute to the reduction of airway obstruction and minimize COPD exacerbations, none can avoid disease progression or reduce mortality. Within this context, recent advances in mesenchymal stromal cell (MSC) therapy have made this approach a strong candidate for clinical use in the treatment of several pulmonary diseases. MSCs can be readily harvested from diverse tissues and expanded with high efficiency, and have strong immunosuppressive properties. Preclinical studies have demonstrated encouraging outcomes of MSCs therapy for lung disorders, including emphysema. These findings instigated research groups to assess the impact of MSCs in human COPD/emphysema, but clinical results have fallen short of expectations. However, MSCs have demonstrated a good adjuvant role in the clinical scenario. Trials that used MSCs combined with another, primary treatment (eg, endobronchial valves) found that patients derived greater benefit in pulmonary function tests and/or quality of life reports, as well as reductions in systemic markers of inflammation. The present review summarizes and describes the more recent preclinical studies that have been published about MSC therapy for COPD/emphysema and discusses what has already been applied about MSCs treatment in COPD patients in the clinical setting.

Bone Marrow, Adipose, and Lung Tissue-Derived Murine Mesenchymal Stromal Cells Release Different Mediators and Differentially Affect Airway and Lung Parenchyma in Experimental Asthma

Mesenchymal stromal cells (MSCs) from different sources have differential effects on lung injury. To compare the effects of murine MSCs from bone marrow (BM), adipose tissue (AD), and lung tissue (LUNG) on inflammatory and remodeling processes in experimental allergic asthma, female C57BL/6 mice were sensitized and challenged with ovalbumin (OVA) or saline (C). Twenty‐four hours after the last challenge, mice received either saline (50 µl, SAL), BM‐MSCs, AD‐MSCs, or LUNG‐MSCs (10⁵ cells per mouse in 50 µl total volume) intratracheally. At 1 week, BM‐MSCs produced significantly greater reductions in resistive and viscoelastic pressures, bronchoconstriction index, collagen fiber content in lung parenchyma (but not airways), eosinophil infiltration, and levels of interleukin (IL)‐4, IL‐13, transforming growth factor (TGF)‐β, and vascular endothelial growth factor (VEGF) in lung homogenates compared to AD‐MSCs and LUNG‐MSCs. Only BM‐MSCs increased IL‐10 and interferon (IFN)‐γ in lung tissue. In parallel in vitro experiments, BM‐MSCs increased M2 macrophage polarization, whereas AD‐MSCs and LUNG‐MSCs had higher baseline levels of IL‐4, insulin‐like growth factor (IGF), and VEGF secretion. Exposure of MSCs to serum specimens obtained from asthmatic mice promoted reductions in secretion of these mediators, particularly in BM‐MSCs. Intratracheally administered BM‐MSCs, AD‐MSCs, and LUNG‐MSCs were differentially effective at reducing airway inflammation and remodeling and improving lung function in the current model of allergic asthma. In conclusion, intratracheal administration of MSCs from BM, AD, and LUNG were differentially effective at reducing airway inflammation and remodeling and improving lung function comparably reduced inflammation and fibrogenesis in this asthma model. However, altered lung mechanics and lung remodeling responded better to BM‐MSCs than to AD‐MSCs or LUNG‐MSCs. Moreover, each type of MSC was differentially affected in a surrogate in vitro model of the in vivo lung environment. Stem Cells Translational Medicine2017;6:1557–1567

Bioprocess integration for human mesenchymal stem cells: From up to downstream processing scale-up to cell proteome characterization

To deliver the required cell numbers and doses to therapy, scaling-up production and purification processes (at least to the liter-scale) while maintaining cells' characteristics is compulsory. Therefore, the aim of this work was to prove scalability of an integrated streamlined bioprocess compatible with current good manufacturing practices (cGMP) comprised by cell expansion, harvesting and volume reduction unit operations using human mesenchymal stem cells (hMSC) isolated from bone marrow (BM-MSC) and adipose tissue (AT-MSC). BM-MSC and AT-MSC expansion and harvesting steps were scaled-up from spinner flasks to 2L scale stirred tank single-use bioreactor using synthetic microcarriers and xeno-free medium, ensuring high cellular volumetric productivities (50×10⁶cellL^-1day^-1), expansion factors (14-16 fold) and cell recovery yields (80%). For the concentration step, flat sheet cassettes (FSC) and hollow fiber cartridges (HF) were compared showing a fairly linear scale-up, with a need to slightly decrease the permeate flux (30-50 LMH, respectively) to maximize cell recovery yield. Nonetheless, FSC allowed to recover 18% more cells after a volume reduction factor of 50. Overall, at the end of the entire bioprocess more than 65% of viable (>95%) hMSC could be recovered without compromising cell's critical quality attributes (CQA) of viability, identity and differentiation potential. Alongside the standard quality assays, a proteomics workflow based on mass spectrometry tools was established to characterize the impact of processing on hMSC's CQA; These analytical tools constitute a powerful tool to be used in process design and development.

Adipose mesenchymal stromal cells minimize and repair radiation-induced oral mucositis

BACKGROUND AIMS

Mesenchymal stromal cells (MSCs) have been used to minimize and repair radiation-induced normal tissue injury in the intestine, salivary gland, liver, skin, lungs and cardiac muscle. This study investigated the ability of adipose tissue-derived MSCs (aMSCs) to minimize and/or repair single dose radiation-induced oral mucositis (RIOM).

METHODS

Syngenic phenotypically and functionally characterized BALB/c mouse aMSCs were implanted intraperitoneally in a RIOM mouse model with different dosing protocols. Response was quantified macroscopically, microscopically and by using different histological and clinically relevant parameters.

RESULTS

Irradiation at 18 Gy generated a self-resolved single-dose RIOM BALB/c mouse model with 5.6 ± 0.3 days mean duration (95% confidence interval (CI) 4.233-7.1 days) and 100% survival rate. Intraperitoneal implantation of 5 doses of 2.5 million freshly cultured syngenic aMSCs significantly and reproducibly reduced RIOM ulcer duration to 1.6 ± 0.3 days (95% CI 0.0233-3.1 days, a 72% reduction in RIOM ulcer duration), ulcer size and ulcer floor epithelial height. The therapeutic benefits were significantly dependent on dose size and frequency, number of doses, and therapy onset time. aMSCs therapy significantly minimized the RIOM-related weight loss, accelerated the weight gain and improved irradiated animals' hydration and nutritional status. aMSCs therapy did not potentiate head and neck cancer in vitro.

CONCLUSIONS

Syngenic freshly cultured aMSCs significantly minimized and repaired radiation-induced oral mucositis with a 72% reduction in ulcer duration. aMSCs dose size and frequency, number of doses and therapy onset time are the main keys for optimized therapeutic outcome. aMSCs therapy did not stimulate Head and Neck cancer cell growth in-vitro.

Efficiency of Cell Therapy in Liver Cirrhosis

We studied safety and clinical efficacy of transplantation of autologous bone marrow cell in complex therapy of 158 patients with chronic hepatitis and cirrhosis of the liver. The efficiency of cell therapy was assessed in 12 months after single injection of the cells. The positive response (alleviation of liver cirrhosis or stabilization of the pathological process) was observed in 70% cases. The efficacy of therapy correlated with the severity and etiology of the disease and was maximum in patients with Child-Pugh class A (in 82.5% cases) and class B liver cirrhosis (in 79% cases); in patients with class C liver cirrhosis, the positive response was achieved in 42.5% cases. In 39 patients, ultrasonic examination performed in 3 years after transplantation revealed no focal lesions or ectopic ossification foci.

Human Bone Marrow-Derived Mesenchymal Stromal Cells Differentially Inhibit Cytokine Production by Peripheral Blood Monocytes Subpopulations and Myeloid Dendritic Cells

The immunosuppressive properties of mesenchymal stromal/stem cells (MSC) rendered them an attractive therapeutic approach for immune disorders and an increasing body of evidence demonstrated their clinical value. However, the influence of MSC on the function of specific immune cell populations, namely, monocyte subpopulations, is not well elucidated. Here, we investigated the influence of human bone marrow MSC on the cytokine and chemokine expression by peripheral blood classical, intermediate and nonclassical monocytes, and myeloid dendritic cells (mDC), stimulated with lipopolysaccharide plus interferon (IFN)γ. We found that MSC effectively inhibit tumor necrosis factor- (TNF-) α and macrophage inflammatory protein- (MIP-) 1β protein expression in monocytes and mDC, without suppressing CCR7 and CD83 protein expression. Interestingly, mDC exhibited the highest degree of inhibition, for both TNF-α and MIP-1β, whereas the reduction of TNF-α expression was less marked for nonclassical monocytes. Similarly, MSC decreased mRNA levels of interleukin- (IL-) 1β and IL-6 in classical monocytes, CCL3, CCL5, CXCL9, and CXCL10 in classical and nonclassical monocytes, and IL-1β and CXCL10 in mDC. MSC do not impair the expression of maturation markers in monocytes and mDC under our experimental conditions; nevertheless, they hamper the proinflammatory function of monocytes and mDC, which may impede the development of inflammatory immune responses.

Mesenchymal stem cell trials for pulmonary diseases

All adult tissues, including the lung, have some capacity to self-repair or regenerate through the replication and differentiation of stem cells resident within these organs. While lung resident stem cells are an obvious candidate cell therapy for lung diseases, limitations exist regarding our knowledge of the biology of these cells. In contrast, there is considerable interest in the therapeutic potential of exogenous cells, particularly mesenchymal stem/stromal cells (MSCs), for lung diseases. Bone marrow derived-MSCs are the most studied cell therapy for these diseases. Preclinical studies demonstrate promising results using MSCs for diverse lung disorders, including emphysema, bronchopulmonary dysplasia, fibrosis, and acute respiratory distress syndrome. This mini-review will summarize ongoing clinical trials using MSCs in lung diseases, critically examine the data supporting their use for this purpose, and discuss the next steps in the translational pathway for MSC therapy of lung diseases.

Effects of different mesenchymal stromal cell sources and delivery routes in experimental emphysema

We sought to assess whether the effects of mesenchymal stromal cells (MSC) on lung inflammation and remodeling in experimental emphysema would differ according to MSC source and administration route. Emphysema was induced in C57BL/6 mice by intratracheal (IT) administration of porcine pancreatic elastase (0.1 UI) weekly for 1 month. After the last elastase instillation, saline or MSCs (1×105), isolated from either mouse bone marrow (BM), adipose tissue (AD) or lung tissue (L), were administered intravenously (IV) or IT. After 1 week, mice were euthanized. Regardless of administration route, MSCs from each source yielded: 1) decreased mean linear intercept, neutrophil infiltration, and cell apoptosis; 2) increased elastic fiber content; 3) reduced alveolar epithelial and endothelial cell damage; and 4) decreased keratinocyte-derived chemokine (KC, a mouse analog of interleukin-8) and transforming growth factor-β levels in lung tissue. In contrast with IV, IT MSC administration further reduced alveolar hyperinflation (BM-MSC) and collagen fiber content (BM-MSC and L-MSC). Intravenous administration of BM- and AD-MSCs reduced the number of M1 macrophages and pulmonary hypertension on echocardiography, while increasing vascular endothelial growth factor. Only BM-MSCs (IV > IT) increased the number of M2 macrophages. In conclusion, different MSC sources and administration routes variably reduced elastase-induced lung damage, but IV administration of BM-MSCs resulted in better cardiovascular function and change of the macrophage phenotype from M1 to M2.

Mesenchymal stem cells from umbilical cord matrix, adipose tissue and bone marrow exhibit different capability to suppress peripheral blood B, natural killer and T cells

Introduction

The ability to self-renew, be easily expanded in vitro and differentiate into different mesenchymal tissues, render mesenchymal stem cells (MSCs) an attractive therapeutic method for degenerative diseases. The subsequent discovery of their immunosuppressive ability encouraged clinical trials in graft-versus-host disease and auto-immune diseases. Despite sharing several immunophenotypic characteristics and functional capabilities, the differences between MSCs arising from different tissues are still unclear and the published data are conflicting.

Methods

Here, we evaluate the influence of human MSCs derived from umbilical cord matrix (UCM), bone marrow (BM) and adipose tissue (AT), co-cultured with phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (MNC), on T, B and natural killer (NK) cell activation; T and B cells’ ability to acquire lymphoblast characteristics; mRNA expression of interleukin-2 (IL-2), forkhead box P3 (FoxP3), T-bet and GATA binding protein 3 (GATA3), on purified T cells, and tumor necrosis factor-alpha (TNF-α), perforin and granzyme B on purified NK cells.

Results

MSCs derived from all three tissues were able to prevent CD4⁺ and CD8⁺ T cell activation and acquisition of lymphoblast characteristics and CD56^dim NK cell activation, wherein AT-MSCs showed a stronger inhibitory effect. Moreover, AT-MSCs blocked the T cell activation process in an earlier phase than BM- or UCM-MSCs, yielding a greater proportion of T cells in the non-activated state. Concerning B cells and CD56^bright NK cells, UCM-MSCs did not influence either their activation kinetics or PHA-induced lymphoblast characteristics, conversely to BM- and AT-MSCs which displayed an inhibitory effect. Besides, when co-cultured with PHA-stimulated MNC, MSCs seem to promote Treg and Th1 polarization, estimated by the increased expression of FoxP3 and T-bet mRNA within purified activated T cells, and to reduce TNF-α and perforin production by activated NK cells.

Conclusions

Overall, UCM-, BM- and AT-derived MSCs hamper T cell, B cell and NK cell-mediated immune response by preventing their acquisition of lymphoblast characteristics, activation and changing the expression profile of proteins with an important role in immune function, except UCM-MSCs showed no inhibitory effect on B cells under these experimental conditions. Despite the similarities between the three types of MSCs evaluated, we detect important differences that should be taken into account when choosing the MSC source for research or therapeutic purposes.

A combination of cytokines rescues highly purified leukemic CLL B-cells from spontaneous apoptosis in vitro

B-chronic lymphocytic leukemia (B-CLL), the most common human leukemia, is characterized by predominantly non-dividing malignant mature CD5+ B lymphocytes with an apoptosis defect. Various microenvironmental stimuli confer a growth advantage on these leukemic cells and extend their survival in vivo. Nevertheless, when cultured in vitro, CLL B-cells rapidly die from apoptosis. Certain cytokines may extend the survival capacity of CLL B-cells in vitro and individual anti-apoptotic effects of several cytokines have been reported. The potential cumulative effect of such cytokines has not been studied. We therefore investigated the effects on CLL B-cells survival in vitro of humoral factors, polyclonal lymphocyte activators and a combination of cytokines known for their anti-apoptotic effects. Purified CLL B-cells were cultured in the presence or absence of various soluble molecules and the leukemic cell response was assessed in terms of viability. Apoptotic cell death was detected by flow cytometry using annexinV and 7-amino-actinomycin. The survival of CLL B-cells in vitro was highly variable. When tested separately, cytokines (IL-2, -6, -10, -12, -15, -21, BAFF and APRIL) improved CLL B cell survival moderately; in combination, they significantly enhanced survival of these cells, even up to 7 days of culture. We also report that humoral factors from autologous serum are important for survival of these malignant cells. Our findings support the concept that the CLL microenvironment is critical and suggest that soluble factors may contribute directly to the prolonged survival of CLL B-cells. Therefore, the combination of cytokines we describe as providing strong resistance to apoptosis in vitro might be used to improve the treatment of CLL.

MSC and Tumors: Homing, Differentiation, and Secretion Influence Therapeutic Potential

: Mesenchymal stromal/stem cells (MSC) are adult multipotent progenitors with fibroblast-like morphology able to differentiate into adipocytic, osteogenic, chondrogenic, and myogenic lineages. Due to these properties, MSC have been studied and introduced as therapeutics in regenerative medicine. Preliminary studies have also shown a possible involvement of MSC as precursors of cellular elements within tumor microenvironments, in particular tumor-associated fibroblasts (TAF). Among a number of different possible origins, TAF may originate from a pool of circulating progenitors from bone marrow or adipose tissue-derived MSC. There is growing evidence to corroborate that cells immunophenotypically defined as MSC are able to reside as TAF influencing the tumor microenvironment in a potentially bi-phasic and obscure manner: either promoting or inhibiting growth depending on tumor context and MSC sources. Here we focus on relationships between the tumor microenvironment, cancer cells, and MSC, analyzing their diverse ability to influence neoplastic development. Associated activities include MSC homing driven by the secretion of various mediators, differentiation towards TAF phenotypes, and reciprocal interactions with the tumor cells. These are reviewed here with the aim of understanding the biological functions of MSC that can be exploited for innovative cancer therapy.