TRANSPLANTATION OF SUBRETINAL STEM CELL-DERIVED RETINAL PIGMENT EPITHELIUM FOR STARGARDT DISEASE: A Phase I Clinical Trial.

PURPOSE: To assess the safety of injecting human embryonic stem cell retinal pigment epithelial cell dose to treat Stargardt disease. METHODS: In this prospective, Phase I clinical trial, human embryonic stem cell retinal pigment epithelial cells in suspension were injected into the subretinal space in eyes with the worse best-corrected visual acuity (BCVA). After vitrectomy/posterior hyaloid removal, a partial retinal detachment was created and the human embryonic stem cell retinal pigment epithelial cells were administered. Phacoemulsification with intraocular lens implantation was performed in eyes with lens opacity. All procedures were optical coherence tomography-guided. The 12-month follow-up included retinal imaging, optical coherence tomography, visual field/electrophysiologic testing, and systemic evaluation. The main outcome was the absence of ocular/systemic inflammation or rejection, tumor formation, or toxicity during follow-up. RESULTS: The mean baseline BCVAs in the phacoemulsification and no phacoemulsification groups were similar (1.950 ± 0.446 and 1.575 ± 0.303, respectively). One year postoperatively, treated eyes showed a nonsignificant increase in BCVA. No adverse effects occurred during follow-up. Intraoperative optical coherence tomography was important for guiding all procedures. CONCLUSION: This surgical procedure was feasible and safe without cellular migration, rejection, inflammation, or development of ocular or systemic tumors during follow-up.

Generation of four induced pluripotent stem cells lines from PBMC of the DFNA58 family members: Two hearing-impaired duplication carriers (USPi006-A e USPi007-A) and two normal-hearing noncarriers (USPi004-A and USPi005-A).

The DFNA58 locus contains a genomic duplication involving three protein-coding genes (CNRIP1, PLEK, and PPP3R1's exon 1) and other uncharacterized lncRNA genes (LOC101927723, LOC107985892 and LOC102724389). To clarify the role of these genes in hearing and precisely determine their role in hearing loss, four iPSC lines were generated from two carriers and two noncarriers of the duplication.

In vitro differentiation of cGMP-grade retinal pigmented epithelium from human embryonic stem cells.

BACKGROUND: The World Health Organization (WHO) estimates that the number of individuals who lose their vision due to retinal degeneration is expected to reach 6 million annually in 2020. The retinal degenerative diseases affect the macula, which is responsible for central and detailed vision. Most macular degeneration, i.e., age-related macular degeneration (AMD) develops in the elderly; however, certain hereditary diseases, such as the Stargardt disease, also affect young people. This degeneration begins with loss of retinal pigmented epithelium (RPE) due to formation of drusen (atrophic) or abnormal vessels (exudative). In wet AMD, numerous drugs are available to successful treat the disease; however, no proven therapy currently is available to treat dry AMD or Stargardt. Since its discovery, human embryonic stem cells (hESCs) have been considered a valuable therapeutic tool. Some evidence has shown that transplantation of RPEs differentiated from hESCs cells can result in recovery of both RPE and photoreceptors and prevent visual loss. METHODS: The human embryonic WA-09 stem cell lineage was cultured under current Good Manufacturing Practices (cGMP) conditions using serum-free media and supplements. The colonies were isolated manually and allowed to spontaneously differentiate into RPE cells. RESULTS: This simple and effective protocol required minimal manipulation and yielded more than 10e8 RPE cells by the end of the differentiation and enrichment processes, with cells exhibiting a cobblestone morphology and displaying cellular markers and a gene expression profile typical of mature RPE cells. Moreover, the differentiated cells displayed phagocytic activity and only a small percentage of the total cells remained positive for the Octamer-binding transcriptions factor 4 (OCT-4) pluripotency cell marker. CONCLUSIONS: These results showed that functional RPE cells can be produced efficiently and suggested the possibility of scaling-up to aim at therapeutic protocols for retinal diseases associated with RPE degeneration.

Beneficial effects of prolactin and laminin on human pancreatic islet-cell cultures.

The problem of pancreas donor shortage could be addressed through in vitro islet-cell proliferation prior to transplantation into diabetic patients. Therefore, we set out to evaluate the effects of prolactin (rhPRL) and laminin on primary cultures of human pancreatic islets. Our results showed that rhPRL induced an increase in islet-cell number and in cumulative insulin secretion (p<0.01). However, glucose-induced insulin secretion was enhanced only in the presence of both laminin and rhPRL. In addition, we describe, for the first time in human islets, the PRL-induced activation of JAK2, and signal transducer and activator of transcription (STAT) 1, 3 and 5. Our results demonstrate a significant beneficial effect of rhPRL and laminin on human islets and support widely held notion that the closer physiological stimuli and environment of beta cells are mimicked, the better are the results in cell proliferation and secretory function, both essential for successful islet transplantation.

Enhanced Proteolytic Processing of Recombinant Human Coagulation Factor VIII B-Domain Variants by Recombinant Furins.

Recombinant human factor VIII (rFVIII) is used in replacement therapy for hemophilia A. Current research efforts are focused on bioengineering rFVIII molecules to improve its secretion efficiency and stability, limiting factors for its efficient production. However, high expression yield in mammalian cells of these rFVIII variants is generally associated with limited proteolytic processing. Non-processed single-chain polypeptides constitute non-natural FVIII molecule configurations with unpredictable toxicity and/or antigenicity. Our main objective was to demonstrate the feasibility of promoting full-proteolytic processing of an rFVIII variant retaining a portion of the B-domain, converting it into the smallest natural activatable form of rFVIII, while keeping its main advantage, i.e., improved secretion efficiency. We generated and employed a CHO-DG44 cell clone producing an rFVIII variant retaining a portion of the B-domain and the FVIII native cleavage site between Arg(1648) and Glu(1649). By bioengineering CHO-DG44 cells to express stably the recombinant human endoproteases PACE, PACE-SOL, PCSK5, PCSK6, or PCKS7, we were able to achieve complete intra- or extracellular proteolytic processing of this rFVIII variant. Additionally, our quantitative data indicated that removal of the B-domain segment by intracellular proteolytic processing does not interfere with this rFVIII variant secretion efficiency. This work also provides the first direct evidence of (1) intracellular cleavage at the Arg(1648) FVIII processing site promoted by wild-type PACE and PCSK7 and (2) proteolytic processing at the Arg(1648) FVIII processing site by PCSK6.