Delayed administration of bone marrow mesenchymal stem cell conditioned medium significantly improves outcome after retinal ischemia in rats.
OBJECTIVE
Delayed treatment after ischemia is often unsatisfactory. We hypothesized that injection of bone marrow stem cell (BMSC) conditioned medium after ischemia could rescue ischemic retina, and in this study we characterized the functional and histological outcomes and mechanisms of this neuroprotection.


METHODS
Retinal ischemia was produced in adult Wistar rats by increasing intraocular pressure for 55 minutes. Conditioned medium (CM) from rat BMSCs or unconditioned medium (uCM) was injected into the vitreous 24 hours after the end of ischemia. Recovery was assessed 7 days after ischemia using electroretinography, at which time we euthanized the animals and then prepared 4-μm-thick paraffin-embedded retinal sections. TUNEL and Western blot were used to identify apoptotic cells and apoptosis-related gene expression 24 hours after injections; that is, 48 hours after ischemia. Protein content in CM versus uCM was studied using tandem mass spectrometry, and bioinformatics methods were used to model protein interactions.


RESULTS
Intravitreal injection of CM 24 hours after ischemia significantly improved retinal function and attenuated cell loss in the retinal ganglion cell layer. CM attenuated postischemic apoptosis and apoptosis-related gene expression. By spectral counting, 19 proteins that met stringent identification criteria were increased in the CM compared to uCM; the majority were extracellular matrix proteins that mapped into an interactional network together with other proteins involved in cell growth and adhesion.


CONCLUSIONS
By restoring retinal function, attenuating apoptosis, and preventing retinal cell loss after ischemia, CM is a robust means of delayed postischemic intervention. We identified some potential candidate proteins for this effect.
Department of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois, United States.
John C
JC
Dreixler
Pritzker School of Medicine, The University of Chicago, Chicago, Illinois, United States.
Jacqueline N
JN
Poston
Department of Surgery (Neurosurgery), The University of Chicago, Chicago, Illinois, United States.
Irina
I
Balyasnikova
Department of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois, United States.
Afzhal R
AR
Shaikh
Department of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois, United States.
Kelsey Y
KY
Tupper
Department of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois, United States.
Sineadh
S
Conway
Department of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois, United States.
Venkat
V
Boddapati
Department of Surgery (Ophthalmology and Visual Science), The University of Chicago, Chicago, Illinois, United States.
Marcus M
MM
Marcet
Department of Surgery (Neurosurgery), The University of Chicago, Chicago, Illinois, United States.
Maciej S
MS
Lesniak
Department of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois, United States.
Steven
S
Roth
D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000166:cytology*; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004195:Disease Models, Animal; D004596:Electroretinography; D005434:Flow Cytometry; D020287:In Situ Nick-End Labeling; D058449:Intravitreal Injections; D007511:Ischemia / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000473:pathology* / Q000503:physiopathology; D012164:Retinal Diseases / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D053719:Tandem Mass Spectrometry; D013997:Time Factors
D017077:Culture Media, Conditioned
conditioned medium; ischemia; retina; stem cells