Caveolin-1 and migration of bone-marrow derived cells in the mouse eye

Characterizing temporal and spatial recruitment of systemically administered RPE65-programmed bone marrow-derived cells to the retina in a mouse model of age-related macular degeneration

PURPOSE

Previously, we reported that the intravenous injection of bone marrow-derived cells (BMDC) infected with lentivirus expressing the human RPE65 gene resulted in the programming of BMDC to promote visual recovery in a mouse model of age-related macular degeneration (AMD). The aim of this study was to characterize the spatial and temporal recruitment of these programmed BMDC to the retinal pigment epithelial (RPE) layer.

METHODS

C57BL/6J female mice received a subretinal injection of AAV1-SOD2 ribozyme to knock down (KD) superoxide dismutase 2 (SOD2) and induce AMD-like pathology. BMDC were isolated from GFP⁺ mice and infected with a lentivirus expressing RPE65. One month after SOD2 KD, fifty thousand GFP⁺ RPE65-BMDC were injected in the mouse tail vein. Animals were terminated at different time points up to 60 min following cell administration, and localization of GFP⁺ cells was determined by fluorescence microscopy of neural retina and RPE flat mounts and tissue sections.

RESULTS

GFP⁺ RPE65- BMDC were observed in SOD2 KD neural retina and RPE as early as 1 min following administration. With increasing time, the number of cells in the neural retina decreased, while those in the RPE increased. While the number of cells in peripheral and central retina remained similar at each time point, the number of BMDC recruited to the central RPE increased in a time-dependent manner up to a maximum by 60 min post administration. Immunohistochemistry of cross-sections of the RPE layer confirmed the incorporation of donor GFP⁺ BMDC into the RPE layer and that these GFP⁺ human RPE65 expressing cells co-localized with murine RPE65. No GFP⁺ cells were observed in the neural retina or RPE layer of normal uninjured control eyes.

CONCLUSIONS

Our study shows that systemically administered GFP⁺ RPE65-BMDC can reach the retina within minutes and that the majority of these BMDC are recruited to the injured RPE layer by 60 min post injection.

In vitro effect of caveolin-1 as a slow-release material on bone-tendon junction healing: A comparative study

Bone tendon junction injury is hard to cure because of its special anatomical structure, and the treatment applied for bone-tendon junction injury cannot result in the perfect vascular regeneration and restoration of the fibrocartilage zone. In this article, we aim to explore the effect of caveolin-1 as a slow-release material on bone-tendon junction healing. Seventy-two New Zealand rabbits were randomly selected and assigned into the experimental, sham-operated and control groups (n = 24). Caveolin-1 microspheres and microcapsule were developed as drug delivery system. At the 4th, 8th, and 12th weeks after surgery, quadriceps muscle patella-patellar tendon (QMPPT) was obtained from each rabbit to observe the tendon-to-bone tunnel healing, and X-ray examination, histological examination and biomechanical testing were applied for evaluating new bone formation. As the X-ray showed, caveolin-1 increased the new bone area at each time point. At the 4th and 8th weeks after surgery, the rabbit treated with caveolin-1 slow release material showed repair of fibrocartilage. According to the biomechanical results, the cross-sectional area, breaking load and ultimate tensile strength were increased along with time. At the same time point, caveolin-1 increased the ultimate tensile strength. Our study demonstrates that caveolin-1 as a slow-release material could accelerate bone-tendon junction healing by promoting the formation of the transition zone.