Document text
Principal Investigator: Juan M Melero-Martin
Organization: BOSTON CHILDREN'S HOSPITAL
Fiscal Year: 2024
Award: $563,978
Funding agency: National Heart Lung and Blood Institute
PROJECT SUMMARY/ABSTRACT
Ischemic diseases, including critical limb ischemia and myocardial infarction, afflict millions of people in the
United States. Currently, these diseases are predominately treated by surgical interventions. However, the
inability to regenerate microvascular beds in ischemic tissues remains a challenge. Alternatively, the
development of therapies based on transplanting endothelial cells (ECs) continues to be a priority in vascular
medicine. Unfortunately, engrafting ECs is not trivial. Studies have repeatedly shown that in order to achieve
significant engraftment resulting in functional new blood vessels, ECs require co-transplantation with supporting
cells such as mesenchymal stromal cells (MSCs). However, this paradigm is problematic because it increases
the complexity of clinical trials exponentially. Previously, we have published extensively on all aspects of human
EC+MSC engraftment. However, the underlying mechanisms by which MSCs facilitate EC engraftment remain
incompletely understood. Recently, we found that upon implantation, MSCs transfer mitochondria to ECs via
tunneling nanotubes and that when this transfer was genetically abrogated, EC engraftment was drastically
impaired. Based on this insight, we propose a new concept: artificially transplanting mitochondria into human
ECs as a means to preemptively enhance their ability to engraft without a secondary cell type. Indeed, our
preliminary data show that transplanting exogenous mitochondria into ECs renders the cells (termed mitoT-ECs)
capable of forming functional vessels in vivo in ischemic tissues, without the support of MSCs. We also found
that transplanted mitochondria co-localized with LC3B-marked autophagosomes and that genetic ablation of
PINK1 and Parkin (both central players in mitophagy) eliminated the enhanced engraftment ability of mitoT-ECs.
Together, our overarching hypothesis is that transplanting exogenous mitochondria into ECs renders transient
cytoprotection via mitophagy; this, in turn, enhances the engraftment ability of the cells. To test this hypothesis
and to determine the efficacy of mitoT-ECs to treat ischemic diseases, we propose two specific aims. In Aim-1,
we will determine conditions (e.g., concentration and timing) for optimal EC engraftment in immunodeficient mice.
We will dissect the role of mitophagy and will examine the fate and persistence of the transplanted mitochondria.
We will also determine if selective drugs with mitophagy-enhancing properties could also enhance EC
engraftment. In Aim-2, we will determine the efficacy of mitochondrial transplantation-enabled EC therapy in two
well-established models of ischemic diseases: critical hind limb ischemia (in mice) and myocardial
ischemia/reperfusion injury (in rats). In summary, we propose studies to develop a novel approach to engraft
ECs more successfully. We envision this research could become the basis for a new strategy in vascular cell
therapies.
Terms: <Ablation><Adenovirus E1b19k-Binding Protein B5><Affect><After Care><After-Treatment><Aftercare><Apoptosis><Apoptosis Pathway><Athymic Rats><Autophagosome><BCL2/Adenovirus E1B 19-Kd Protein-Interacting Protein 3a><BCL2/Adenovirus E1B 19kd Interacting Protein 3-Like><BNIP3a><Biogenesis><Blood Vessels><Blood flow><Body Tissues><Cardiac infarction><Cell Body><Cell Line><Cell Protection><Cell Therapy><CellLine><Cells><Centrifugation><Centrifugation Fractionation><Clinical Trials><Common Rat Strains><Complement><Complement Proteins><Cytolysis><Cytoprotection><Data><Disease><Disorder><Drugs><Echocardiogram><Echocardiography><Endocytosis><Endothelial Cells><Endothelium><Engraftment><Evaluation><FLJ11330><Fibrosis><Genetic><Goals><Human><Immunodeficient Mouse><Impairment><Infarction><Ischemia><Laser Electromagnetic><Laser Radiation><Lasers><Lysis><Measures><Mediating><Mediator><Medication><Medicine><Methods><Mice><Mice Mammals><Microcirculatory Bed><Microvascular Bed><Mitochondria><Mitochondrial DNA><Modeling><Modern Man><Murine><Mus><Myocardial Infarct><Myocardial Infarction><Myocardial Ischemic Reperfusion Injury><Myocardial Reperfusion Injury><NF-Kb-Activating Kinase Gene><NIX><Nanotubes><Natural regeneration><Nude Rats><Operative Procedures><Operative Surgical Procedures><Organ><Origin of Life><PARK6><PARK6 gene><PARK6 protein><PINK1><PINK1 gene><PINK1 gene product><PINK1 protein><PTEN induced kinase 1><PTEN induced putative kinase 1><PTEN-induced putative kinase><Parkin><Parkin gene><Parkinson disease 6 gene><Pathway interactions><Perfusion><Persons><Pharmaceutical Preparations><Phosphatase and tensin homolog induced kinase 1><Pinocytosis><Process><Programmed Cell Death><Property><Publishing><Rat><Rats Mammals><Rattus><Recovery><Regeneration><Research><Role><Strains Cell Lines><Supporting Cell><Surgical><Surgical Interventions><Surgical Procedure><T2K><TBK1><TBK1 gene><Technology><Testing><Tissues><Transplantation><Transthoracic Echocardiography><United States><cardiac infarct><cell mediated therapies><cell type><cell-based therapeutic><cell-based therapy><cellular therapeutic><cellular therapy><complementation><coronary attack><coronary infarct><coronary infarction><critical limb Ischemia><cultured cell line><cytoprotective><determine efficacy><develop therapy><drug/agent><effective therapy><effective treatment><efficacy analysis><efficacy assessment><efficacy determination><efficacy evaluation><efficacy examination><evaluate efficacy><examine efficacy><experience><heart attack><heart infarct><heart infarction><heart sonography><heteroplasmy><imager><implantation><improved><in vivo><infarct><insight><intervention development><ischemic limb><limb ischemia><mesenchymal stromal cell><mitochondrial><mtDNA><new approaches><novel approaches><novel strategies><novel strategy><oxidation><parkin protein><pathway><post treatment><pressure><protein kinase BRPK><protein kinase BRPK gene><regenerate><revascularization><serine/threonine-protein kinase PINK1><social role><surgery><therapy development><transplant><treatment development><vascular>