A Promising Tool in Retina Regeneration: Current Perspectives and Challenges When Using Mesenchymal Progenitor Stem Cells in Veterinary and Human Ophthalmological Applications
Stem Cell Rev and Rep (2017) 13:598–602 DOI 10.1007/s12015-017-9750-4
Anna Cislo-Pakuluk1 & Krzysztof Marycz2
Visual impairment is a common ailment of the cur- rent world population, with more exposure to CCD screens and fluorescent lighting, approximately 285 billion people suffer from this deficiency and 13% of those are considered clinically blind. More common causes for visual impairment include age-related macular degeneration (AMD), glaucoma and diabetic retinopathy (Zhu et al. Molecular Medicine Reports, 2015; Kolb et al. 2007; Machalińska et al. Current Eye Research, 34(9),748–760, 2009) among a few. As cases of retinal and optic nerve diseases rise, it is vital to find a treatment, which has led to investigation of the therapeutic potential of various stem cells types (Bull et al. Investigative Opthalmology & Visual Science, 50(9), 4244, 2009; Bull et al.Investigative Opthalmology & Visual Science, 49(8), 3449,2008; Yu et al. Biochemical and Biophysical Research Communications, 344(4), 1071-1079, 2006; Na et al.Graefe’s Archive for Clinical and Experimental Ophthalmology, 247(4), 503-514, 2008). In previous studies, some of the stem cell variants used include human Muller SCs and bone marrow derived SCs. Some of the regenerative po- tential characteristics of mesenchymal progenitor stem cells (MSCs) include their multilineage differentiation potential, their immunomodulatory effects, their high proliferative activ- ity, they can be easily cultured in vitro, and finally their po- tential to synthesize and secrete membrane derived vesicles rich in growth factors, mRNA and miRNA which possibly aid
Recent evidence demonstrates that WJ-MSCs are potential transplantable cells for treatment of devastating diseases, such as cancer and diabetes. Their use in cell therapy will be an integral addition to the field of regeneration. WJ-MSCs have a multitude of benefits such as their high proliferation rate , lower doubling time, and ability to function with non- immune-suppressed animals . However, there remains paucity in the translation of WJ- MSCs for clinical use, largely due to the cells’ heterogeneity, which results from the current isolation methods and inefficient staining methods . There are two primary explanations for heterogeneity. First, the hUC has multiple distinct anatomical zones, and previous attempts at isolating WJ-MSCs have inadvertently harvested cells from different anatomical structures of the hUC in addition to the Wharton’s Jelly. Second, there is currently wide variation in procedures to harvest WJ-MSCs, and this variation can produce inconsistent results between studies . Future research and refinement of isolation procedures can potentially overcome these obstacles . Regardless of these drawbacks WJ-MCSs are still the ideal future for cell therapy; their properties of high proliferation capability and versatility to differentiate between three lineages allow them to lower immunogenicity and have the potential to treat an array of diseases and disorders .
In addition, WJ-MSCs stimulate immune responses from B and T cells  and suppress cytotoxic and natural killer cells . WJ-MSCs possess cytokines and growth factor receptors, which allow them to be vital tools for cancer therapy. In such therapy, WJ-MCSs drastically weaken the cancerous tumors by secreting therapeutic proteins which promote the cancerous cells to undergo cell death and to stop the cell cycle ; moreover, WJ- MSCs enhance the immune response to cancer cells. With the minimum risk of spreading the cancer cells throughout the body or to the MSC donor, WJ-MSCs have the potential to serve as vehicles for delivery of tumor suppressive genes and anticancer drugs occur.
Apart from cancer treatment WJ-MCSs also can facilitate cell-based therapies for liver diseases and diabetes mellitus due to their high proliferation and differentiation ability , e.g., WJ-MSCs can express hepatoblastic phenotypes and can become liver cells or pancreatic cells .
As we recognized the many versatile capabilities of WJ-MSCs, their documented efficacy in animal models and limited clinical trials as therapeutic cells advances the field of regenerative medicine. With more research, WJ-MSCs may someday become recognized as routine donor cells for cell-based therapies [49, 50, 51].