Erythropoietin Pretreatment of Transplanted Endothelial Colony-Forming Cells Enhances Recovery in a Cerebral Ischemia Model by Increasing Their Homing Ability: A SPECT/CT Study.
Endothelial colony-forming cells (ECFCs) are promising candidates for cell therapy of ischemic diseases, as less than 10% of patients with an ischemic stroke are eligible for thrombolysis. We previously reported that erythropoietin priming of ECFCs increased their in vitro and in vivo angiogenic properties in mice with hindlimb ischemia. The present study used SPECT/CT to evaluate whether priming of ECFCs with erythropoietin could enhance their homing to the ischemic site after transient middle cerebral artery occlusion (MCAO) followed by reperfusion in rats and potentiate their protective or regenerative effect on blood-brain barrier (BBB) disruption, cerebral apoptosis, and cerebral blood flow (CBF).


METHODS
Rats underwent a 1-h MCAO followed by reperfusion and then 1 d after MCAO received an intravenous injection of either PBS (control, n = 10), PBS-primed ECFCs (ECFCPBS, n = 13), or erythropoietin-primed ECFCs (ECFCEPO, n = 10). ECFC homing and the effect on BBB disruption, cerebral apoptosis, and CBF were evaluated by SPECT/CT up to 14 d after MCAO. The results were expressed as median ± interquartile range for ipsilateral-to-contralateral ratio of the activity in middle cerebral artery-vascularized territories in each hemisphere. Histologic evaluation of neuronal survival and astrocytic proliferation was performed on day 14.


RESULTS
Erythropoietin priming increased homing of ECFCs to the ischemic hemisphere (ECFCPBS, 111.0% ± 16.0%; ECFCEPO, 146.5% ± 13.3%). BBB disruption was significantly reduced (control, 387% ± 153%; ECFCPBS, 151% ± 46% [P < 0.05]; ECFCEPO, 112% ± 9% [P < 0.001]) and correlated negatively with ECFC homing (Pearson r = -0.6930, P = 0.0002). Cerebral apoptosis was significantly reduced (control, 161% ± 10%; ECFCPBS, 141% ± 9% [P < 0.05]; ECFCEPO,118% ± 5% [P < 0.001]) and correlated negatively with ECFC homing (r = -0.7251, P < 0.0001). CBF was significantly restored with ECFCs and almost totally so with erythropoietin priming (control, 72% ± 2%; ECFCPBS, 90% ± 4% [P < 0.01]; ECFCEPO, 99% ± 4% [P < 0.001]) and correlated positively with ECFC homing (r = 0.7348, P < 0.0001). Immunoblocking against the CD146 receptor on ECFCs highlighted its notable role in ECFC homing with erythropoietin priming (ECFCEPO, 147% ± 14%, n = 4; ECFCEPOwith antibody against CD146, 101% ± 12%, n = 4 [P < 0.05]).


CONCLUSIONS
Priming with erythropoietin before cell transplantation is an efficient strategy to amplify the migratory and engraftment capacities of ECFCs and their beneficial impact on BBB disruption, apoptosis, and CBF.
UMR_S 1076, INSERM, Aix Marseille Univ., Marseille, France.|CERIMED, Aix Marseille Univ., Marseille, France.|Service Radiopharmacie, Hôpital Nord, APHM, Marseille, France.
Philippe
P
Garrigue
UMR_S 1076, INSERM, Aix Marseille Univ., Marseille, France.
Guillaume
G
Hache
UMR_S 1076, INSERM, Aix Marseille Univ., Marseille, France.
Youssef
Y
Bennis
LIIE, Aix Marseille Univ., Marseille, France.
Pauline
P
Brige
UMR_S 1076, INSERM, Aix Marseille Univ., Marseille, France.
Jimmy
J
Stalin
UMR_S 1076, INSERM, Aix Marseille Univ., Marseille, France.
Lionel
L
Pellegrini
Département Anesthésie-Réanimation Adulte, APHM, Marseille, France.
Lionel
L
Velly
Advanced Accelerator Applications, Colleretto-Giacosa, Italy.
Francesca
F
Orlandi
Advanced Accelerator Applications, Colleretto-Giacosa, Italy.
Elena
E
Castaldi
UMR_S 1076, INSERM, Aix Marseille Univ., Marseille, France.|Service d'Hématologie, Hôpital Conception, APHM, Marseille, France; and.
Françoise
F
Dignat-George
UMR_S 1076, INSERM, Aix Marseille Univ., Marseille, France.|Laboratoire de Culture et Thérapie Cellulaire, Hôpital Conception, APHM, Marseille, France.
Florence
F
Sabatier
UMR_S 1076, INSERM, Aix Marseille Univ., Marseille, France benjamin.guillet@univ-amu.fr.|CERIMED, Aix Marseille Univ., Marseille, France.|Service Radiopharmacie, Hôpital Nord, APHM, Marseille, France.
Benjamin
B
Guillet
D000818:Animals; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000628:therapy*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects* / Q000637:transplantation*; D004921:Erythropoietin / Q000008:administration & dosage*; D008297:Male; D011292:Premedication / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D000072098:Single Photon Emission Computed Tomography Computed Tomography / Q000379:methods*; D033581:Stem Cell Transplantation / Q000379:methods; D016896:Treatment Outcome
D004921:Erythropoietin
ECFC; apoptosis; blood–brain barrier; cerebral blood flow; homing; ischemic stroke