Transplantation of iPSC-TM stimulates division of trabecular meshwork cells in human eyes

Abstract

the trabecular meshwork's (tM) physiological role is to maintain normal intraocular pressure by regulating aqueous humor outflow. With age, and particularly in eyes with primary open angle glaucoma, the number of cells residing within the tM is markedly decreased and the function of the tissue is compromised. Here we evaluate if transplantation of induced pluripotent stem cell derived tM like cells (ipSc-tM) restores tM cellularity and function in human eyes obtained from older human donors. Human iPSC were differentiated into iPSC-TM and compared to primary TM cells by RNAseq. ipSc-tM were then injected into the anterior segments of human eyes maintained in perfusion culture. Seven and 14 days eyes after injection eyes that received iPSC-TM contained significantly more cells in the TM. Fewer than 1% of all cells appeared to be iPSC-TM, but significantly more cells in these eyes were immunopositive for Ki 67 and incorporated BrdU. Our study demonstrates that transplantation ipSc-tM stimulates proliferation of endogenous tM cells in perfusion cultured human eyes from aged donors. These data, in concert with our previous findings in animal models, suggest that functional regeneration of the tM may be possible in human eyes with primary open angle glaucoma.

Looking into the future: Gene and cell therapies for glaucoma

“…Interestingly, the main therapeutic effect of the transplantation occurred via induction of proliferation of the remaining endogenous trabecular meshwork cells. These results were verified in human eye perfusion culture 116 . Potential future clinical application may involve the collection of skin cells from glaucoma patients, followed by creation of iPSCs and induction of trabecular meshwork cells.…”

Xeno- and Feeder-Free Differentiation of Human iPSCs to Trabecular Meshwork-Like Cells by Recombinant Cytokines

“…The observation that iPSC differentiation occurs in two stages is also supported by our previous study, which suggested that differentiated iPSCs display a very stable transcriptional signature after induction for 1 month. 9 Given the roles of the conditioned medium in iPSC differentiation, receptors were assumed to function importantly to transduce the differentiation signals. In this study, we reanalyzed the data to identify highly expressed receptors in each stage of iPSC differentiation through AutoSOME analysis ( Fig.…”

“… 13 We subsequently improved differentiation by using HTM cells, a differentiation approach that appears to be more successful than the use of human immortalized TM cells according to the morphology of differentiated iPSCs. 9 …”

“…Here, we first defined two stages of iPSC differentiation through morphological analysis and bioinformatic analysis of RNA-sequencing data of TM-like cells. 9 From each stage, highly expressed receptors associated with TM development were selected through AutoSOME ( http://jimcooperlab.mcdb.ucsb.edu/autosome ) and Gene Ontology analysis, further confirmed by reverse transcription polymerase chain reaction (RT-PCR) analysis. Recombinant cytokines binding to these receptors were used to generate the new xeno- and feeder-free differentiation approach, which can effectively induce human iPSCs to differentiate into TM-like cells, by studying their morphological features and conducting immunohistochemistry analyses and transcriptomic assays.…”

The trabecular meshwork: Structure, function and clinical implications. A review of the literature

“…Ding et al have succeeded in obtaining iPSC cells with a phenotype close to that of human TMC after placing them in co-culture with human TMC [120]. Transplantation of these cells into perfused human anterior segments or into animal models stimulated proliferation of the endogenous TMC [121] and restored aqueous outflow, thus lowering IOP [122]. This type of iPSC based therapy is a promising strategy for IOP regulation in glaucoma patients [123].…”