Inhibition of NF-κB improves the stress resistance and myogenic differentiation of MDSPCs isolated from naturally aged mice

A decline in the regenerative capacity of adult stem cells with aging is well documented. As a result of this decline, the efficacy of autologous stem cell therapies is likely to decline with increasing donor age. In these cases, strategies to restore the function of aged stem cells would have clinical utility. Globally, the transcription factor NF-κB is up-regulated in aged tissues. Given the negative role that NF-κB plays in myogenesis, we investigated whether the age-related decline in the function of muscle-derived stem/progenitor cells (MDSPCs) could be improved by inhibition of NF-κB. Herein, we demonstrate that pharmacologic or genetic inhibition of NF-κB activation increases myogenic differentiation and improves resistance to oxidative stress. Our results suggest that MDSPC “aging” may be reversible, and that pharmacologic targeting of pathways such as NF-κB may enhance the efficacy of cell-based therapies

Extracellular Vesicles Secreted by Hypoxic AC10 Cardiomyocytes Modulate Fibroblast Cell Motility

Extracellular vesicles (EVs) are small membrane vesicles secreted by most cell types with important roles in cell-to-cell communication. To assess their relevance in the context of heart ischemia, EVs isolated from the AC10 ventricular cardiomyocyte cell line (CM-EVs), exposed to normoxia (Nx) or hypoxia (Hx), were incubated with fibroblasts (Fb) and endothelial cells (EC). CM-EVs were studied using electron microscopy, nanoparticle tracking analysis (NTA), western blotting and proteomic analysis. Results showed that EVs had a strong preference to be internalized by EC over fibroblasts, suggesting an active exosome-based communication mechanism between CM and EC in the heart. In Matrigel tube-formation assays, Hx CM-EVs were inferior to Nx CM-EVs in angiogenesis. By contrast, in a wound-healing assay, wound closure was faster in fibroblasts treated with Hx CM-EVs than with Nx CM-EVs, supporting a pro-fibrotic effect of Hx CM-EVs. Overall, these observations were consistent with the different protein cargoes detected by proteomic analysis under Nx and Hx conditions and the biological pathways identified. The paracrine crosstalk between CM-EVs, Fb, and EC in different physiological conditions could account for the contribution of CM-EVs to cardiac remodeling after an ischemic insult

HIF-Overexpression and Pro-Inflammatory Priming in Human Mesenchymal Stromal Cells Improves the Healing Properties of Extracellular Vesicles in Experimental Crohn’s Disease

Extracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) have therapeutic potential in the treatment of several immune disorders, including ulcerative colitis, owing to their regenerative and immunosuppressive properties. We recently showed that MSCs engineered to overexpress hypoxia-inducible factor 1-alpha and telomerase (MSC-T-HIF) and conditioned with pro-inflammatory stimuli release EVs (EVMSC-T-HIFC) with potent immunomodulatory activity. We tested the efficacy of EVMSC-T-HIFC to repolarize M1 macrophages (Mφ1) to M2-like macrophages (Mφ2-like) by analyzing surface markers and cytokines and performing functional assays in co-culture, including efferocytosis and T-cell proliferation. We also studied the capacity of EVMSC-T-HIFC to dampen the inflammatory response of activated endothelium and modulate fibrosis. Finally, we tested the therapeutic capacity of EVMSC-T-HIFC in an acute colitis model. EVMSC-T-HIFc induced the repolarization of monocytes from Mφ1 to an Mφ2-like phenotype, which was accompanied by reduced inflammatory cytokine release. EVMSC-T-HIFc-treated Mφ1 had similar effects of immunosuppression on activated peripheral blood mononuclear cells (PBMC) as Mφ2, and reduced the adhesion of PBMCs to activated endothelium. EVMSC-T-HIFc also prevented myofibroblast differentiation of TGF-β-treated fibroblasts. Finally, administration of EVMSC-T-HIFc promoted healing in a TNBS-induced mouse colitis model in terms of preserving colon length and intestinal mucosa architecture and altering the ratio of Mφ1/ Mφ2 infiltration. In conclusion, EVMSC-T-HIFC have effective anti-inflammatory properties, making them potential therapeutic agents in cell free-based therapies for the treatment of Crohn’s disease and likely other immune-mediated inflammatory diseases

NR5A2/LRH-1 regulates the PTGS2-PGE2-PTGER1 pathway contributing to pancreatic islet survival and function

LRH-1/NR5A2 is implicated in islet morphogenesis postnatally, and its activation using the agonist BL001 protects islets against apoptosis, reverting hyperglycemia in mouse models of Type 1 Diabetes Mellitus. Islet transcriptome profiling revealed that the expression of PTGS2/COX2 is increased by BL001. Herein, we sought to define the role of LRH-1 in postnatal islet morphogenesis and chart the BL001 mode of action conferring beta cell protection. LRH-1 ablation within developing beta cells impeded beta cell proliferation, correlating with mouse growth retardation, weight loss, and hypoglycemia leading to lethality. LRH-1 deletion in adult beta cells abolished the BL001 antidiabetic action, correlating with beta cell destruction and blunted Ptgs2 induction. Islet PTGS2 inactivation led to reduced PGE levels and loss of BL001 protection against cytokines as evidenced by increased cytochrome c release and cleaved-PARP. The PTGER1 antagonist—ONO-8130—negated BL001-mediated islet survival. Our results define the LRH-1/PTGS2/PGE/PTGER1 signaling axis as a key pathway mediating BL001 survival properties.The authors are supported by grants from the Consejería de Salud, Fundación Pública Andaluza Progreso y Salud, Junta de Andalucía (PI-0727-2010 to B.R.G., PI-0085-2013 to P.I.L., PI-0247-2016 to F.J.B.S.), the Consejería de Economía, Innovación y Ciencia (P10.CTS.6359 to B.R.G.), the Ministerio de Ciencia e Innovación co-funded by Fondos FEDER (PI10/00871, PI13/00593 and BFU2017-83588-P to B.R.G and PI17/01004 to F.J.B.S.), Vencer el Cancer (B.R.G), DiabetesCero (B.R.G.) and the Juvenile Diabetes Research Foundation Ltd (17-2013-372 and 2-SRA-2019-837-S-B to B.R.G.). E.M.V. is recipient of a Fellowship from the Ministerio de Ciencia e Innovación co-funded by Fondos FEDER (PRE2018-084907). F.J.B.S. is a recipient of a "Nicolás Monardes" research contracts from Consejería de Salud Junta de Andalucía, (C-0070-2012). A.M.M. is supported by CPII19/00023 and PI18/01590 from the Instituto de Salud Carlos III co-funded by Fondos FEDER. V.C. is supported by a AECC investigator award. CIBERDEM is an initiative of the Instituto de Salud Carlos III

Hypoxia-inducible factor 1 alpha contributes to cardiac healing in mesenchymal stem cells-mediated cardiac repair

12 p.-6 fig.-1 tab.Mesenchymal stem cells (MSC) are effective in treating myocardial infarction (MI) and previous reports demonstrated that hypoxia improves MSC self-renewal and therapeutics. Considering that hypoxia-inducible factor- 1 alpha (HIF-1a) is a master regulator of the adaptative response to hypoxia, we hypothesized that HIF-1a overexpression in MSC could mimic some of the mechanisms triggered by hypoxia and increase their therapeutic potential without hypoxia stimulation. Transduction of MSC with HIF-1a lentivirus vectors (MSC-HIF) resulted in increased cell adhesion and migration, and activation of target genes coding for paracrine factors. When MSC-HIF were intramyocardially injected in infarcted nude rats, significant improvement was found (after treatment of infarcted rats with MSC-HIF) in terms of cardiac function, angiogenesis, cardiomyocyte proliferation, and reduction of fibrotic tissue with no induction of cardiac hypertrophy. This finding provides evidences for a crucial role of HIF-1a on MSC biology and suggests the stabilization of HIF-1a as a novel strategy for cellular therapies.This work was supported in part by grants from the Instituto de Salud Carlos III for the Regenerative Medicine Program of Valencian Community to Centro de Investigación Principe Felipe, KUTXA founding and from the FIS (PI07/784, CP08/80 and PI10/00743).Peer reviewe

Plasmatic Membrane Expression of Adhesion Molecules in Human Cardiac Progenitor/Stem Cells Might Explain Their Superior Cell Engraftment after Cell Transplantation

© 2020 Imelda Ontoria-Oviedo et al.Human bone marrow mesenchymal stem cells (BM-MSCs) and cardiac progenitor/stem cells (CPCs) have been extensively studied as a potential therapeutic treatment for myocardial infarction (MI). Previous reports suggest that lower doses of CPCs are needed to improve cardiac function relative to their bone marrow counterparts. Here, we confirmed this observations and investigated the surface protein expression profile that might explain this effect. Myocardial infarction was performed in nude rats by permanent ligation of the left coronary artery. Cardiac function and infarct size before and after cell transplantation were evaluated by echocardiography and morphometry, respectively. The CPC and BM-MSC receptome were analyzed by proteomic analysis of biotin-labeled surface proteins. Rats transplanted with CPCs showed a greater improvement in cardiac function after MI than those transplanted with BM-MSCs, and this was associated with a smaller infarct size. Analysis of the receptome of CPCs and BM-MSCs showed that gene ontology biological processes and KEGG pathways associated with adhesion mechanisms were upregulated in CPCs compared with BM-MSCs. Moreover, the membrane protein interactome in CPCs showed a strong relationship with biological processes related to cell adhesion whereas the BM-MSCs interactome was more related to immune regulation processes. We conclude that the stronger capacity of CPCs over BM-MSCs to engraft in the infarcted area is likely linked to a more pronounced cell adhesion expression program.The proteomic studies were carried out at the University of Valencia Proteomics Unit, a member of the ISCIII ProteoRed Proteomics Platform. Imelda Ontoria-Oviedo acknowledges a post-doctoral contract from for the PlaGenT, Generalitat Valenciana (CDPT-01/20-A). We thank Dr. Kenneth McCreath for constructive comments on the manuscript. This work was supported by grants PI16/0107, PI19/00245, and RETICS Program (RD16/0011/0004) from Instituto de Salud Carlos III cofunded by FEDER “una manera de hacer Europa.

Interfering with the IFNγ pathway in MSCs by specific silencing of the IFNγR and analysis of apoptosis in MSCs.

<p>(A) Lentiviral-mediated shRNA transduction of MSCs was used to knock down the IFNγR. MSCs were transduced either with the empty vector (MSC-pLV) (upper panel) as control or with an IFNγR specific shRNA (MSC-IFNγRi) (lower panel). GFP expression in transduced cells was analysed four days after transduction by Flow Cytometry. (B) The efficiency of gene silencing was quantified by Real-Time qPCR in MSCs transduced either with the empty vector or with the one specific for IFNγRi. mRNA expression for IFNγR was significantly reduced in MSC-IFNγRi compared to MSC-pLV. Relative expression was normalized to the empty vector (MSC-pLV). (C) Transduction of MSCs does not lead to apoptotic cell death. Flow cytometric analysis of apoptotic cells (APC positive cells) in MSC-pLV (left) and MSC-IFNγRi (right) by AnnexinV staining 6 days after transduction.</p

Multiple compounds improve aged MDSPC proliferation (self-renewal).

<p>(A) Aged MDSPCs were cultured in medium containing aspirin, nordihydroguaiaretic acid (NDGA), or rapamycin, and proliferation was monitored by live cell imaging for up to 60 hours, or (B) cells were treated in fusion medium and assessed for myogenic differentiation after 5 days (*p≤0.05 Aged WT vs Treated; ANOVA followed by Tukey post-hoc analysis).</p

NF-κB inhibition improves the differentiation of MDSPCs isolated from old mice.

<p>(A) Brightfield images demonstrate a dose dependent increase in myotube formation following IKKi administration (10x images). (B) Immunofluorescent staining for MyHC demonstrated significantly improved differentiation following treatment at the 5μM dose (20x magnification), quantified in (C). (D) The total number of nuclei per field of view for experiment in B, C (*p≤0.05; ANOVA followed by Tukey post-hoc analysis). (E) IKKi treatment of young WT MDSPCs did not significantly improve differentiation (*p≤0.05, T-test).</p

NF-κB inhibition decreases senescence in BM-MSCs.

<p>BM-MSCs were treated for 48 hours with IKK inhibitor VII and then stained for senescence-associated beta-galactosidase (SA β-gal) expression, which demonstrated a decrease in cell senescence (*p≤0.05, T-test).</p