Project description:MiRNA microarray analysis was performed on exosomes secreted by mouse MSC cells under two different conditions of normal oxygen and hypoxia, in order to find out the different miRNAs in exosomes secreted by MSC under two different conditions.
Project description:Suture mesenchymal stem cell (MSC) drives calvarial suture development, homeostasis, and regeneration. Its loss leads to craniosynostosis, a prevailing craniofacial disorder characterized by premature suture closure. Ribosome biogenesis, historically thought to be a static house-keeping process, is now known to have tissue-specific roles. However, the functional specificity of ribosome biogenesis in suture MSCs remains largely unexplored, hampering development of therapeutic strategies for craniofacial tissue regeneration. We genetically perturb ribosome biogenesis using Snord118, a small nucleolar RNA (snoRNA) required for ribosomal RNA (rRNA) maturation. MSC specific conditional knockout (cKO) of Snord118 in mice leads to p53 activation, cell death, mesenchymal and MSC loss, impaired osteogenic and osteoclastic activity, resulting in suture growth and craniosynostosis defects. Using our newly established human induced pluripotent stem cell (iPSC)-derived MSCs combined with ribosome profiling, we found that SNORD118deficiency in MSCs causes global translation dysregulations and downregulation of complement pathway, a part of innate immune system with selective but poorly characterized physiological functions in craniofacial tissue homeostasis. Overall, ribosome biogenesis controls suture MSC fate via selective regulation of complement pathway.
Project description:Suture mesenchymal stem cell (MSC) drives calvarial suture development, homeostasis, and regeneration. Its loss leads to craniosynostosis, a prevailing craniofacial disorder characterized by premature suture closure. Ribosome biogenesis, historically thought to be a static house-keeping process, is now known to have tissue-specific roles. However, the functional specificity of ribosome biogenesis in suture MSCs remains largely unexplored, hampering development of therapeutic strategies for craniofacial tissue regeneration. We genetically perturb ribosome biogenesis using Snord118, a small nucleolar RNA (snoRNA) required for ribosomal RNA (rRNA) maturation. MSC specific conditional knockout (cKO) of Snord118 in mice leads to p53 activation, cell death, mesenchymal and MSC loss, impaired osteogenic and osteoclastic activity, resulting in suture growth and craniosynostosis defects. Using our newly established human induced pluripotent stem cell (iPSC)-derived MSCs combined with ribosome profiling, we found that SNORD118deficiency in MSCs causes global translation dysregulations and downregulation of complement pathway, a part of innate immune system with selective but poorly characterized physiological functions in craniofacial tissue homeostasis. Overall, ribosome biogenesis controls suture MSC fate via selective regulation of complement pathway.
Project description:Adipose tissue (AT) contains mesenchymal stromal cells (MSC) in stages of commitment to becoming specialized tissue cells, including adipocytes and fibroblasts, and immune cells which support tissue homeostasis. How MSC and immune cells interact during infection is poorly understood. We show that during intestinal helminth infection MSC in mesenteric AT (mAT) become enriched in non-differentiated progenitor cells. This is accompanied by MSC-intrinsic metabolic reprogramming supporting increased secretion of extracellular matrix (ECM), IL-33, and TSLP. In parallel, Th2 resident memory (Th2RM) cells populate the mAT and persist after infection is resolved. These cells express Areg, TGFβ and IL-5, and are necessary to promote infection induced changes within mAT, including MSC reprogramming and tissue eosinophilia. In turn, IL-33 and TSLP from MSC facilitate Th2RM activation and maintenance. Our findings link Th2RM cells to mAT remodeling during intestinal infection, underscoring the reciprocal dependence of stroma and resident immune cells for lasting tissue immunity.
Project description:Aims: Mesenchymal stem cells (MSCs) gradually become attractive candidates for cardiac inflammation modulation, yet understanding of the mechanism remains elusive. Strikingly, recent studies indicated that exosomes secreted by MSCs might be a novel mechanism for the beneficial effect of MSCs transplantation after myocardial infarction. We therefore explored the role of MSC-derived exosomes (MSC-Exo) in the immunomodulation of macrophages after myocardial ischemia-reperfusion and its implications in cardiac injury repair. Methods and Results: Exosomes were isolated from the supernatant of MSCs using a gradient centrifugation method. Administration of MSC-Exo through intramyocardial injection after myocardial ischemia reperfusion reduced infarct size and alleviated inflammation level in heart and serum. Systemic depletion of macrophages with clodronate liposomes abolished the curative effects of MSC-Exo. MSC-Exo modified the polarization of M1 macrophages to M2 macrophages both in vivo and in vitro. miRNA-sequencing of MSC-Exo and bioinformatics analysis implicated miR-182 as a potent candidate mediator of macrophage polarization and TLR4 as a downstream target. Diminishing miR-182 in MSC-Exo partially attenuated its modulation of macrophage polarization. Likewise, knock down of TLR4 also conferred cardioprotective efficacy and reduced inflammation level in a mouse model of myocardial ischemia/reperfusion. Conclusion: Our data indicates that MSC-Exo attenuates myocardial ischemia/reperfusion injury via shuttling miR-182 that modifies the polarization state of macrophages. This study sheds new light on the application of MSC-Exo a potential therapeutic tool for myocardial ischemia/reperfusion injury.
Project description:Primary cortical neurons were isolated from E15 mice and after 6 days in vitro were untreated or treated for 24 h with mesenchymal stem cell conditioned medium. Neuron gene expression was profiled and compared between the two different conditions (neurons and neurons+MSC cm) to investigate the molecular mechanisms of MSC neuroprotection. Mesenchymal stem cells (MSC) promote functional recovery in experimental models of central nervous system (CNS) pathology and are currently being tested in clinical trials for stroke, multiple sclerosis and CNS injury. Their beneficial effects are attributed to the activation of endogenous CNS protection and repair processes as well as immune regulation but their mechanisms of action are poorly understood. Here we investigated the neuroprotective effects of mouse MSC in rodent MSC-neuron co-cultures and mice using models of glutamate excitotoxicity. A 24 hr pre-culture of mouse primary cortical neurons with MSC protected them against glutamate (NMDA) receptor-induced death and conditioned medium from MSC (MSC CM) was sufficient for this effect. Protection by MSC CM was associated with reduced mRNA levels of genes encoding NMDA receptor subunits, and increased levels for genes associated with non-neuronal and stem cell types, as shown by RT-PCR and cDNA microarray analyses. Changes in gene expression were not associated with alterations in cell lineage representation within the cultures. Further, MSC CM-mediated neuroprotection in rat retinal ganglion cells was associated with reduced glutamate-induced calcium influx. The adoptive transfer of EGFP+MSC in a mouse kainic acid epilepsy model also provided neuroprotection against glutamate excitotoxicity in vivo, as shown by reduced neuron damage and glial cell activation in the hippocampus. These results show that MSC mediate direct neuroprotection by reducing neuronal sensitivity to glutamate receptor ligands and altering gene expression, and suggest a link between the therapeutic effects of MSC and the activation of cell plasticity in the damaged CNS.
Project description:The graft-versus-host disease (GVHD) associated dry eye disease usually leads to refractory pain and visual impairment with limited treatments currently. Here we found exosome derived from mesenchymal stromal cell (MSC-exo) administered as eye drops significantly alleviates GVHD-associated dry eye disease in human and mouse models. To find out the essential elements during exosome treatment, we performed miRNA sequencing of exosomes derived from MSCs and L929 cells, and identified miR-204 in MSC-exo benefited the recovery of dry eye, which targeted IL-6/IL-6R/Stat3 signaling. Blockade of miR-204 abolished the therapeutic effect of MSC-exo while miR-204 overexpression from L929-exo markedly attenuates dry eye. Thus MSC-exo eye drops are efficacious in treating GVHD-associated dry eye and highlight miR-204 as a potential therapeutic agent.
Project description:miRNA profiles of the MSC-MVs and EPO-MVs were analyzed with a quantitative PCR (qPCR)-based array of the whole mice genome. Further analysis revealed differences in the miRNAs of 212 EPO-MVs (fold change ≥ 1.5 compared to the MSC-MVs), which constituted approximately 22.64% of all of the evaluated mouse miRNAs. Of all of the differences, 70.28% of the changes in the EPO-MV group involved upregulation