This study was supported by the National Key R&#38;D Program of China (2016YFC1101103, 2017YFA0104101), the Guangzhou Science and Technology Project Fund (201803010078), the Science &#38; Technology Project of Guangdong Province (2017B020230003), the Natural Science Foundation (NSF) of China (81570874, 81970842), Hundred talent program of Sun Yat-sen University (PT1001010), and the Fundamental Research Funds of the State Key Laboratory of Ophthalmology.

1. Culture and expansion of hPSCs
<ol>
	<li>HPSC culture
	<ol>
		<li>Coat two wells of a 6-well plate with extracellular matrix (ECM, hESC-qualified matrix). Prepare 50 mL of an ECM solution containing 8-12 &#181;g/mL of ECM in Dulbecco&#39;s Modified Eagle&#39;s Medium (DMEM). In 49&#160;mL of DMEM, add 1 mL of the thawed ECM stock solution (50x). Add 1 mL of the ECM solution to each well of a 6-well plate. Incubate it for 1 h in an incubator at 37 &#176;C and 5% CO2.</li>
		<li>Prepare hPS...

<ol>
	<li>Flaxman, S. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+causes+of+blindness+and+distance+vision+impairment+1990-2020:+a+systematic+review+and+meta-analysis.">Global causes of blindness and distance vision impairment 1990-2020: a systematic review and meta-analysis.</a> The Lancet Global Health. 5 (12), 1221-1234 (2017).</li><li>Sayed, N., Liu, C., Wu, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Translation+of+human-induced+pluripotent+stem+cells:+From+clinical+trial+in+a+dish+to+precision+medicine.">Translation of human-induced pluripotent stem cells: From clinical trial in a dish to precision medicine.</a> Journal of American College of Cardiology. 67 (18), 2161-2176 (2016).</li><li>Capowski, E. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reproducibility+and+staging+of+3D+human+retinal+organoids+across+multiple+pluripotent+stem+cell+lines.">Reproducibility and staging of 3D human retinal organoids across multiple pluripotent stem cell lines.</a> Development. 146 (1), (2019).</li><li>Brooks, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+retinal+organoid+differentiation+by+modulating+signaling+pathways+revealed+by+comparative+transcriptome+analyses+with+development+in+vivo.">Improved retinal organoid differentiation by modulating signaling pathways revealed by comparative transcriptome analyses with development in vivo.</a> Stem Cell Reports. 13 (5), 891-905 (2019).</li><li>Zerti, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developing+a+simple+method+to+enhance+the+generation+of+cone+and+rod+photoreceptors+in+pluripotent+stem+cell-derived+retinal+organoids.">Developing a simple method to enhance the generation of cone and rod photoreceptors in pluripotent stem cell-derived retinal organoids.</a> Stem Cells. 38 (1), 45-51 (2020).</li><li>Osakada, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+the+generation+of+rod+and+cone+photoreceptors+from+mouse,+monkey+and+human+embryonic+stem+cells.">Toward the generation of rod and cone photoreceptors from mouse, monkey and human embryonic stem cells.</a> Nature Biotechnology. 26 (2), 215-224 (2008).</li><li>Nakano, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-formation+of+optic+cups+and+storable+stratified+neural+retina+from+human+ESCs.">Self-formation of optic cups and storable stratified neural retina from human ESCs.</a> Cell Stem Cell. 10 (6), 771-785 (2012).</li><li>Zhong, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+three-dimensional+retinal+tissue+with+functional+photoreceptors+from+human+iPSCs.">Generation of three-dimensional retinal tissue with functional photoreceptors from human iPSCs.</a> Nature Communication. 5, 4047 (2014).</li><li>Liu, C., Oikonomopoulos, A., Sayed, N., Wu, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+human+diseases+with+induced+pluripotent+stem+cells:+from+2D+to+3D+and+beyond.">Modeling human diseases with induced pluripotent stem cells: from 2D to 3D and beyond.</a> Development. 145 (5), (2018).</li><li>Lamba, D. A., Gust, J., Reh, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transplantation+of+human+embryonic+stem+cell-derived+photoreceptors+restores+some+visual+function+in+Crx-deficient+mice.">Transplantation of human embryonic stem cell-derived photoreceptors restores some visual function in Crx-deficient mice.</a> Cell Stem Cell. 4 (1), 73-79 (2009).</li><li>Reichman, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+confluent+human+iPS+cells+to+self-forming+neural+retina+and+retinal+pigmented+epithelium.">From confluent human iPS cells to self-forming neural retina and retinal pigmented epithelium.</a> Proceedings of the National Academy of Sciences. 111 (23), 8518-8523 (2014).</li><li>Maeda, A., Mandai, M., Takahashi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+and+Induced+Pluripotent+Stem+Cell+Therapy+for+Retinal+Diseases.">Gene and Induced Pluripotent Stem Cell Therapy for Retinal Diseases.</a> Annual Review Genomics and Human Genetics. 20, 201-216 (2019).</li><li>Kruczek, K., Swaroop, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pluripotent+stem+cell-derived+retinal+organoids+for+disease+modeling+and+development+of+therapies.">Pluripotent stem cell-derived retinal organoids for disease modeling and development of therapies.</a> Stem Cells. 38 (10), 1206-1215 (2020).</li><li>O'Hara-Wright, M., Gonzalez-Cordero, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinal+organoids:+a+window+into+human+retinal+development.">Retinal organoids: a window into human retinal development.</a> Development. 147 (24), (2020).</li><li>Eckert, P., Knickmeyer, M. D., Schutz, L., Wittbrodt, J., Heermann, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphogenesis+and+axis+specification+occur+in+parallel+during+optic+cup+and+optic+fissure+formation,+differentially+modulated+by+BMP+and+Wnt.">Morphogenesis and axis specification occur in parallel during optic cup and optic fissure formation, differentially modulated by BMP and Wnt.</a> Open Biology. 9 (2), 180179 (2019).</li><li>Patel, A., Sowden, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genes+and+pathways+in+optic+fissure+closure.">Genes and pathways in optic fissure closure.</a> Seminals in Cell and Development Biology. 91, 55-65 (2019).</li><li>Chan, B. H. C., Moosajee, M., Rainger, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Closing+the+Ggap:+Mechanisms+of+epithelial+fusion+during+optic+fissure+closure.">Closing the Ggap: Mechanisms of epithelial fusion during optic fissure closure.</a> Frontiers in Cell and Developmental Biology. 8, (2021).</li><li>Li, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+retinal+organoids+with+mature+rods+and+cones+from+urine-derived+human+induced+pluripotent+stem+cells.">Generation of retinal organoids with mature rods and cones from urine-derived human induced pluripotent stem cells.</a> Stem Cells International. 2018, 4968658 (2018).</li><li>Liu, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-formation+of+RPE+spheroids+facilitates+enrichment+and+expansion+of+hiPSC-derived+RPE+generated+on+retinal+organoid+induction+platform.">Self-formation of RPE spheroids facilitates enrichment and expansion of hiPSC-derived RPE generated on retinal organoid induction platform.</a> Investigative Ophthalmology and Visual Science. 59 (13), 5659-5669 (2018).</li><li>Luo, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+optimized+system+for+effective+derivation+of+three-dimensional+retinal+tissue+via+Wnt+signaling+regulation.">An optimized system for effective derivation of three-dimensional retinal tissue via Wnt signaling regulation.</a> Stem Cells. 36 (11), 1709-1722 (2018).</li><li>Li, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+and+characterization+of+induced+pluripotent+stem+cells+and+retinal+organoids+from+a+leber's+congenital+amaurosis+patient+with+novel+RPE65+mutations.">Generation and characterization of induced pluripotent stem cells and retinal organoids from a leber's congenital amaurosis patient with novel RPE65 mutations.</a> Frontiers in Molecular Neuroscience. 12, 212 (2019).</li><li>Matsa, E., Ahrens, J. H., Wu, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+induced+pluripotent+stem+cells+as+a+platform+for+personalized+and+precision+cardiovascular+medicine.">Human induced pluripotent stem cells as a platform for personalized and precision cardiovascular medicine.</a> Physiology Reviews. 96 (3), 1093-1126 (2016).</li><li>Wahlin, K. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoreceptor+outer+segment-like+structures+in+long-term+3d+retinas+from+human+pluripotent+stem+cells.">Photoreceptor outer segment-like structures in long-term 3d retinas from human pluripotent stem cells.</a> Science Reports. 7 (1), 766 (2017).</li><li>Eiraku, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-organizing+optic-cup+morphogenesis+in+three-dimensional+culture.">Self-organizing optic-cup morphogenesis in three-dimensional culture.</a> Nature. 472 (7341), 51-56 (2011).</li><li>Reichman, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+storable+retinal+organoids+and+retinal+pigmented+epithelium+from+adherent+human+iPS+cells+in+xeno-free+and+feeder-free+conditions.">Generation of storable retinal organoids and retinal pigmented epithelium from adherent human iPS cells in xeno-free and feeder-free conditions.</a> Stem Cells. 35 (5), 1176-1188 (2017).</li><li>Lamba, D. A., Karl, M. O., Ware, C. B., Reh, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+generation+of+retinal+progenitor+cells+from+human+embryonic+stem+cells.">Efficient generation of retinal progenitor cells from human embryonic stem cells.</a> Proceedings of the National Academy of Science U. S. A. 103 (34), 12769-12774 (2006).</li><li>Kuwahara, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+a+ciliary+margin-like+stem+cell+niche+from+self-organizing+human+retinal+tissue.">Generation of a ciliary margin-like stem cell niche from self-organizing human retinal tissue.</a> Nature Communication. 6, 6286 (2015).</li><li>da Silva, S., Cepko, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fgf8+expression+and+degradation+of+retinoic+acid+are+required+for+patterning+a+high-acuity+area+in+the+retina.">Fgf8 expression and degradation of retinoic acid are required for patterning a high-acuity area in the retina.</a> Developmental Cell. 42 (1), 68-81 (2017).</li><li>Mitchell, D. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinoic+acid+signaling+regulates+differential+expression+of+the+tandemly-duplicated+long+wavelength-sensitive+cone+opsin+genes+in+zebrafish.">Retinoic acid signaling regulates differential expression of the tandemly-duplicated long wavelength-sensitive cone opsin genes in zebrafish.</a> PLoS Genetics. 11 (8), 1005483 (2015).</li><li>Stevens, C. B., Cameron, D. A., Stenkamp, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasticity+of+photoreceptor-generating+retinal+progenitors+revealed+by+prolonged+retinoic+acid+exposure.">Plasticity of photoreceptor-generating retinal progenitors revealed by prolonged retinoic acid exposure.</a> BMC Developmental Biology. 11 (1), (2011).</li><li>Eldred, K. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thyroid+hormone+signaling+specifies+cone+subtypes+in+human+retinal+organoids.">Thyroid hormone signaling specifies cone subtypes in human retinal organoids.</a> Science. 362 (6411), (2018).</li><li>Yang, F., Ma, H., Ding, X. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thyroid+hormone+signaling+in+retinal+development,+survival,+and+disease.">Thyroid hormone signaling in retinal development, survival, and disease.</a> Vitamins and Hormones. 106, 333-349 (2018).</li><li>Brzezinski, J. A., Reh, T. 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A. 116 (22), 10824-10833 (2019).</li><li>Lowe, A., Harris, R., Bhansali, P., Cvekl, A., Liu, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intercellular+adhesion-dependent+cell+survival+and+ROCK-regulated+actomyosin-driven+forces+mediate+self-formation+of+a+retinal+organoid.">Intercellular adhesion-dependent cell survival and ROCK-regulated actomyosin-driven forces mediate self-formation of a retinal organoid.</a> Stem Cell Reports. 6 (5), 743-756 (2016).</li><li>Carcamo-Orive, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+transcriptional+variability+in+a+large+human+ipsc+library+reveals+genetic+and+non-genetic+determinants+of+heterogeneity.">Analysis of transcriptional variability in a large human ipsc library reveals genetic and non-genetic determinants of heterogeneity.</a> Cell Stem Cell. 20 (4), 518-532 (2017).</li><li>DeBoever, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+profiling+reveals+the+influence+of+genetic+variation+on+gene+expression+in+human+induced+pluripotent+stem+cells.">Large-scale profiling reveals the influence of genetic variation on gene expression in human induced pluripotent stem cells.</a> Cell Stem Cell. 20 (4), 533-546 (2017).</li></ol>

In this multi-step retinal induction protocol, hPSCs were guided step by step to gain the retinal fate, and self-organized into retinal organoids containing laminated NR and RPE. During the differentiation, hPSCs recapitulated all major steps of human retinal development in vivo, from EF, OV, and RPE, to retinal lamination, generating all subtypes of retinal cells, including retinal ganglion cells, amacrine cells, bipolar cells, rod, and cone photoreceptors, and muller glial cells in a spatial and temporal order...

Retinal degenerative diseases (RDs), such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP), are characterized by the dysfunction and death of photoreceptor cells and typically lead to irreversible vision loss without effective ways to cure1. The mechanism underlying these diseases is largely unknown partially due to lack of human disease models2. Over the past decades, significant advances have been accomplished in regenerative medicine through stem cell technology. Many researchers, including ourselves, have shown that human pluripotent stem cells (hPSCs), including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), can differentiate into all types of retinal cells, even mini-retinal tissues through various differentiation approaches3,4,5,6,7,8,9,10,11, providing huge potential in disease modeling and cell therapy12,13,14.
However, the induction process from hPSCs to retinal cells is highly complicated and&#160;time-consuming with low repeatability, which requires researchers with rich experience and high skills. During the complex and dynamic induction process, a number of factors will impact the yield of retinal tissues15,16,17. Also, different induction methods often vary considerably in timing and robust expression of retinal markers, which might confound the sample collection and data interpretation3. Therefore, a straightforward protocol of retinal differentiation from hPSCs with step-by-step guidance would be in demand.
Here, based on our published studies18,19,20,21, an optimized retinal induction protocol to generate retinal organoids (ROs) with rich cone photoreceptors from hPSCs is described, which does not require the supplement of retinoic acid (RA). This protocol focuses on the description of the multi-step method to generate neural retina and RPE. EB formation is the essential part of the early induction stage. Both size and plating density of EBs are quantitatively optimized, which scientifically enhances the yield of retinal tissues and promotes repeatability. In the second part of the induction, optic vesicles (OVs) self-organize in the adherence culture and ROs form in the suspension culture; the time courses and efficiencies of this part vary considerably in different hPSC lines. The maturation and specification of retinal cells in ROs mainly occur in the middle and late stage of induction. Without the addition of RA, mature photoreceptors with both rich cones and rods can be produced.
The purpose of this protocol is to quantitatively describe and detail each step for inexperienced researchers to repeat. Various hPSC lines have been successfully induced into ROs by this protocol with a robust yield of cone-rich retinal tissues and high repeatability. HPSCs-derived ROs with this protocol can recapitulate the main steps of retinal development in vivo, and survive long-term, which facilitates downstream applications, such as disease modeling, drug screening, and cell therapy.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>(&#8722;)-Blebbistatin</td>
			<td>Sigma</td>
			<td>B0560-5mg</td>
			<td>ROCK-inhibitor</td>
		</tr>
		<tr>
			<td>1 ml tips</td>
			<td>Kirgen</td>
			<td>KG1313</td>
			<td>1 ml</td>
		</tr>
		<tr>
			<td>10 ml pipette</td>
			<td>Sorfa</td>
			<td>3141001</td>
			<td>Pipette</td>
		</tr>
		<tr>
			<td>100 mm Tissue culture</td>
			<td>BIOFIL</td>
			<td>TCD000100</td>
			<td>100 mm Petri dish</td>
		</tr>
		<tr>
			<td>100 mm Tissue culture</td>
			<td>Falcon</td>
			<td>353003</td>
			<td>100 mm Petri dish</td>
		</tr>
		<tr>
			<td>15 ml Centrifuge tubes</td>
			<td>BIOFIL</td>
			<td>CFT011150</td>
			<td>Centrifuge tubes</td>
		</tr>
		<tr>
			<td>35 mm Tissue culture dishes</td>
			<td>Falcon</td>
			<td>353001</td>
			<td>35 mm Petri dish</td>
		</tr>
		<tr>
			<td>5 ml pipette</td>
			<td>Sorfa</td>
			<td>313000</td>
			<td>Pipette</td>
		</tr>
		<tr>
			<td>50 ml Centrifuge tubes</td>
			<td>BIOFIL</td>
			<td>CFT011500</td>
			<td>Centrifuge tubes</td>
		</tr>
		<tr>
			<td>6 wells tissue culture plates</td>
			<td>Costar</td>
			<td>3516</td>
			<td>Culture plates</td>
		</tr>
		<tr>
			<td>Anti-AP2&#945; Antibody</td>
			<td>DSHB</td>
			<td>3b5</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>ANTIBIOTIC ANTIMYCOTIC 100X</td>
			<td>Gibco</td>
			<td>15240062</td>
			<td>Antibiotic-Antimycotic</td>
		</tr>
		<tr>
			<td>Anti-ISL1 Antibody</td>
			<td>Boster</td>
			<td>BM4446</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>Anti-Ki67 Antibody</td>
			<td>Abcam</td>
			<td>ab15580</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>Anti-L/M opsin Antibody</td>
			<td>gift from Dr. jeremy</td>
			<td>/</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>Anti-PAX6 Antibody</td>
			<td>DSHB</td>
			<td>pax6</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>Anti-rabbit 555</td>
			<td>Invitrogen</td>
			<td>A31572</td>
			<td>Donkey anti-Rabbit IgG (H+L) 
			Secondary Antibody, Alexa Fluor 555</td>
		</tr>
		<tr>
			<td>Anti-Recoverin Antibody</td>
			<td>Millipore</td>
			<td>ab5585</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>Anti-Rhodopsin Antibody</td>
			<td>Abcam</td>
			<td>ab5417</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>Anti-sheep 555</td>
			<td>Invitrogen</td>
			<td>A21436</td>
			<td>Donkey anti-Sheep IgG (H+L) 
			Secondary Antibody, Alexa Fluor 555</td>
		</tr>
		<tr>
			<td>Anti-SOX9 Antibody</td>
			<td>Abclonal</td>
			<td>A19710</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>Anti-VSX2 Antibody</td>
			<td>Millipore</td>
			<td>ab9016</td>
			<td>Primary&#160;antibody</td>
		</tr>
		<tr>
			<td>B-27 supplement W/O VIT A (50X)</td>
			<td>Gibco</td>
			<td>12587010</td>
			<td>Supplement</td>
		</tr>
		<tr>
			<td>Cryotube vial</td>
			<td>Thermo scientific-NUNC</td>
			<td>375418</td>
			<td>1.8 ml</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>DOJINDO</td>
			<td>D532</td>
			<td>4&#39;,6-Diamidino-2-phenylindole 
			dihydrochloride; multiple suppliers</td>
		</tr>
		<tr>
			<td>Dimethyl sulphoxide(DMSO) Hybri-max</td>
			<td>Sigma</td>
			<td>D2650-100ML</td>
			<td>Multiple suppliers</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Gibco</td>
			<td>C11995500BT</td>
			<td>Medium</td>
		</tr>
		<tr>
			<td>DMEM /F12</td>
			<td>Gibco</td>
			<td>C11330500BT</td>
			<td>Medium</td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Invitrogen</td>
			<td>15575-020</td>
			<td>0.5 M PH 8.0</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>NATOCOR</td>
			<td>SFBE</td>
			<td>Serum</td>
		</tr>
		<tr>
			<td>Filter</td>
			<td>Millipore</td>
			<td>SLGP033RB</td>
			<td>0.22&#956;m, sterile Millex filter</td>
		</tr>
		<tr>
			<td>GlutaMax, 100X</td>
			<td>Gibco</td>
			<td>35050061</td>
			<td>L-alanyl-L-glutamine</td>
		</tr>
		<tr>
			<td>Heparin</td>
			<td>Sigma</td>
			<td>H3149</td>
			<td>2 mg/ml in PBS to use</td>
		</tr>
		<tr>
			<td>Matrigel, 100x</td>
			<td>Corning</td>
			<td>354277</td>
			<td>Extracellular matrix (ECM)</td>
		</tr>
		<tr>
			<td>MEM Non-Essential Amino Acids Solution (100X)</td>
			<td>Gibco</td>
			<td>11140050</td>
			<td>MEM NEAA</td>
		</tr>
		<tr>
			<td>mTeSR1</td>
			<td>STEM CELL</td>
			<td>85850</td>
			<td>hPSCs maintenance medium (MM)</td>
		</tr>
		<tr>
			<td>N2 supplement</td>
			<td>Gibco</td>
			<td>17502048</td>
			<td>Supplement</td>
		</tr>
		<tr>
			<td>Phosphate-buffered saline (PBS) buffer</td>
			<td>GNM</td>
			<td>GNM10010</td>
			<td>Without Ca+,Mg+,PH7.2&#177;0.1 0.1M</td>
		</tr>
		<tr>
			<td>Taurine</td>
			<td>Sigma</td>
			<td>T0625</td>
			<td>Supplement</td>
		</tr>
		<tr>
			<td>Ultra-low attachment culture dishes 100mm petri dish, low-attachment</td>
			<td>Corning</td>
			<td>CLS3262-20EA</td>
			<td>Petri dish</td>
		</tr>
	</tbody>
</table>

retinal organoid induction system for derivation of 3d retinal tissues from human pluripotent stem cells

Retinal degenerative diseases are the main causes of irreversible blindness without effective treatment. Pluripotent stem cells that have the potential to differentiate into all types of retinal cells, even mini-retinal tissues, hold huge promises for patients with these diseases and many opportunities in disease modeling and drug screening. However, the induction process from hPSCs to retinal cells is complicated and time-consuming. Here, we describe an optimized retinal induction protocol to generate retinal tissues with high reproducibility and efficiency, suitable for various human pluripotent stem cells. This protocol is performed without the addition of retinoic acid, which benefits the enrichment of cone photoreceptors. The advantage of this protocol is the quantification of EB size and plating density to significantly enhance the efficiency and repeatability of retinal induction. With this method, all major retinal cells sequentially appear and recapitulate the main steps of retinal development. It will facilitate downstream applications, such as disease modeling and cell therapy.

The retinal induction process in this protocol mimics the development of human fetal retina. To initiate the retinal differentiation, hPSCs were dissociated into small clumps and cultured in suspension to induce the formation of EBs. On D1, the uniformed cell aggregates or EBs formed (Figure 1C). The culture medium was gradually transitioned into NIM. On D5, EBs were plated onto the ECM-coated culture dishes. Cells gradually migrated out of the EBs (Figure 1D). ...

Watch this Scientific Journal Video about Retinal Organoid Induction System for Derivation of 3D Retinal Tissues from Human Pluripotent Stem Cells at JoVE.com

Retinal Organoid Induction System for Derivation of 3D Retinal Tissues from Human Pluripotent Stem Cells

Here we describe an optimized retinal organoid induction system, which is suitable for various human pluripotent stem cell lines to generate retinal tissues with high reproducibility and efficiency.

Retinal degenerative diseases are the main causes of irreversible blindness without effective treatment. Pluripotent stem cells that have the potential to ...

The induction process from hPSCs to retinal cells is complicated and time-consuming. This optimized protocol can generate retinal tissues with high reproducibility and no cost. The advantage of this protocol is the quantification of EB size and plating density to significantly enhance the efficiency and repeatability of retinal induction from hPSCs.With this method, all major retinal cells sequentially appear and recapitulate the main steps of retinal development. It will facilitate disease modeling and cell therapy for retinal degenerative diseases. Demonstrating the procedure, we are with Yuanyuan Guan, a PhD student, and Bingbing Xie, a technician from the laboratory.Begin by preparing 50 mL of ECM solution by adding 1 mL of the third 50 times stock solution to 50 mL of DMEM. Then, add 1 mL of this prepared ECM solution to each well of a six-well plate and incubate it for one hour at 37 degrees Celsius and 5%carbon dioxide. Prepare hPSC maintenance medium according to the manufacturer's instruction and prewarm it to room temperature for 30 minutes.Pour a cryogenic vial of hPSCs from a liquid nitrogen tank by incubating it in a water bath at 37 degrees Celsius for 30 seconds. Carefully disinfect it using a 75%alcohol spray and put it in a bio-safety cabinet. Transfer the cell suspension from the vial to a 15 millimeter tube.Then, add 5 mL of pre-warmed maintenance medium drop-by-drop to the tube using a 5 mL pipette, while gently shaking the tube to blend the hPSCs. Centrifuge the tube at 170 times G for five minutes. Carefully remove most of the supernatant using a 1 mL pipette, leaving behind approximately 50 microliters of supernatant to avoid losing the cells.Re-suspend the pellet with 1 mL of maintenance medium by pipetting up and down. Remove ECM from the pre-coated wells and add 1.5 milliliters of maintenance medium to each well. Then distribute 0.5 milliliters of cell suspension into each well.Gently shake the plate to distribute the hPSCs uniformly. Put the plate in an incubator at 37 degrees Celsius and 5%carbon dioxide for at least 24 hours to promote cell adherence. Change medium every day and passage hPSCs at 80%confluence.On Day-0, initiate the differentiation by removing the 80%confluence cells from one well of the six-well plate. Collect the cells with EDTA dissociation solution as described in the text manuscript. Remove the EDTA solution and add 1 mL of maintenance medium containing 10 micromolar fluvastatin to stop cell dissociation.Collect the cells with a 1 mL pipette. Transfer the cell suspension to a 100 millimeter ultra-low attached Petri dish and add 9 mL of maintenance medium containing 10 micromolar fluvastatin to the dish. Gently shake the dish twice to distribute the cells uniformly.Then, put it in the incubator at 37 degrees Celsius and 5%carbon dioxide. After the cells are cultured for at least 24 hours, observe them under the microscope. Add 9 mL of maintenance medium and 3 mL of NIM to a 15 mL tube.Transfer the cell cultures to a 15 mL centrifuge tube and add 10 mL of the pre-warmed NIM mixture to the dish. Centrifuge the tube at 60 times G for 3 minutes to collect the aggregates. Then remove the supernatant using a 5 mL pipette, leaving behind approximately 500 microliters to avoid losing cells.Add 2 mL of the mixture to the tube and transfer the suspension back to the same Petri dish. Gently shake the dish to uniformly distribute the cell aggregates. Then, put the dish back in the incubator.On Day-5, remove ECM from the pre-coated dishes and add 10 mL pre-warmed NIM to each dish. Take out the dish containing Ebs and check the quality of EBs under the microscope, making sure that they are bright and round. Collect all EBs in a 15 mL tube and allow them to settle for 5 minutes.Then, remove most of the supernatant, leaving behind about 2 mL of medium. After counting the EBs, seed them drop-by-drop at a density of approximately 2-3 EBs per square centimeter into coated dishes containing 10 mL of NIM. Gently shake the dishes to distribute the EBs uniformly and put them in the incubator for at least 24 hours.Use a tungsten needle or a needle with a 1 mL syringe to mechanically detach the morphologically identifiable optic vesicles, along with the adjacent retinal pigment epithelium on days 28 to 35. Culture them in suspension. Put 50-60 optic vesicles into each 100 millimeter low attachment culture dish, containing 15 mL of RDM for retinal organoid formation.Change the medium every 2 to 3 days until Day-42. To initiate the retinal differentiation, hPSCs were dissociated into small clumps and cultured in suspension, which formed EBs since Day-1. On Day-5 EBs were plated onto the ECM-coated culture dishes and the cells gradually migrated out of the EBs.On Day-16, the induction medium was replaced by RDM, causing the neural retina domains to form and gradually protrude from the dish, as well as, cell forming optic vesicle-like structures surrounded by RPE cells. During Days-28 to 35, retinal organoids consisting of the neural retina, attached to an RPE sphere. At one side, cells formed.As retinal differentiation and specification progressed, hPSCs produced subtypes of neural retina that gradually lined up in layers, mimicking the architectural features of a native human retina. Retinal ganglion cells were first generated from retinal progenitors and accumulated in the basal side of the neuro retina. With this protocol, retinal organoids developed into highly mature photoreceptors with both, rich rods and cones.Photoreceptor cells were located in the apical side, while amacrine cells, horizontal cells, bipolar cells and muller glial cells were all located in the intermediate layer of the neural retina. The key points of this protocol are creating high quality of Ebs and seeding them at the right density.

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5.5K Views.  Sun Yat-sen University, Guangzhou, China, 510060. The induction process from hPSCs to retinal cells is complicated and time-consuming. This optimized protocol can generate retinal tissues with high reproducibility and no cost. The advantage of this protocol is the quantification of EB size and plating density to significantly enhance the efficiency and repeatability of retinal induction from hPSCs.With this method, all major retinal cells sequentially appear and recapitulate the main steps of retinal development. It will facilitate di...

Video: Retinal Organoid Induction System for Derivation of 3D Retinal Tissues from Human Pluripotent Stem Cells

A Simplified Technique for In situ Excision of Cornea and Evisceration of Retinal Tissue from Human Ocular Globe

Enucleation is the process of retrieving the ocular globe from a cadaveric donor leaving the rest of the globe undisturbed. Excision refers to the retrieval of ocular tissues, especially cornea, by cutting it separate from the ocular globe. Evisceration is the process of removing the internal organs referred here as retina. The ocular globe consists of the cornea, the sclera, the vitreous body, the lens, the iris, the retina, the choroid, muscles etc (Suppl. Figure 1). When a patient is suffering from corneal damage, the cornea needs to be removed and a healthy one must be transplanted by keratoplastic surgeries. Genetic disorders or defects in retinal function can compromise vision. Human ocular globes can be used for various surgical procedures such as eye banking, transplantation of human cornea or sclera and research on ocular tissues. However, there is little information available on human corneal and retinal excision, probably due to the limited accessibility to human tissues. Most of the studies describing similar procedures are performed on animal models. Research scientists rely on the availability of properly dissected and well-conserved ocular tissues in order to extend the knowledge on human eye development, homeostasis and function. As we receive high amount of ocular globes out of which approximately 40% (Table 1) of them are used for research purposes, we are able to perform huge amount of experiments on these tissues, defining techniques to excise and preserve them regularly.
The cornea is an avascular tissue which enables the transmission of light onto the retina and for this purpose should always maintain a good degree of transparency. Within the cornea, the limbus region, which is a reservoir of the stem cells, helps the reconstruction of epithelial cells and restricts the overgrowth of the conjunctiva maintaining corneal transparency and clarity. The size and thickness of the cornea are critical for clear vision, as changes in either of them could lead to distracted, unclear vision. The cornea comprises of 5 layers; a) epithelium, b) Bowman's layer, c) stroma, d) Descemet's membrane and e) endothelium. All layers should function properly to ensure clear vision4,5,6. The choroid is the intermediate tunic between the sclera and retina, bounded on the interior by the Bruch's membrane and is responsible for blood flow in the eye. The choroid also helps to regulate the temperature and supplies nourishment to the outer layers of the retina5,6. The retina is a layer of nervous tissue that covers the back of the ocular globe (Suppl. Figure 1) and consists of two parts: a photoreceptive part and a non-receptive part. The retina helps to receive the light from the cornea and lens and converts it into the chemical energy eventually transmitted to the brain with help of the optic nerve5,6.
The aim of this paper is to provide a protocol for the dissection of corneal and retinal tissues from human ocular globes. Avoiding cross-contamination with adjacent tissues and preserving RNA integrity is of fundamental importance as such tissues are indispensable for research purposes aimed at (i) characterizing the transcriptome of the ocular tissues, (ii) isolating stem cells for regenerative medicine projects, and (iii) evaluating histological differences between tissues from normal/affected subjects. In this paper we describe the technique we currently use to remove the cornea, the choroid and retinal tissues from an ocular globe. Here we provide a detailed protocol for the dissection of the human ocular globe and the excision of corneal and retinal tissues. The accompanying video will help researchers to learn an appropriate technique for the retrieval of precious human tissues which are difficult to find regularly.

A Simplified Technique for In situ Excision of Cornea and Evisceration of Retinal Tissue from Human Ocular Globe

The paper describes a simplified technique to excise corneal and to eviscerate retinal tissues from the ocular globe of human cadaveric donors. The technique described here will help to excise good quality tissues to be used for transplantation, surgical or research purposes without damaging other tissues of the ocular globe.

Enucleation is the process of retrieving the ocular globe from a cadaveric donor leaving the rest of the globe undisturbed. Excision refers to the ...

Isolation, Characterization and Comparative Differentiation of Human Dental Pulp Stem Cells Derived from Permanent Teeth by Using Two Different Methods

Developing wisdom teeth are easy-accessible source of stem cells during the adulthood which could be obtained by routine orthodontic treatments. Human pulp-derived stem cells (hDPSCs) possess high proliferation potential with multi-lineage differentiation capacity compare to the ordinary source of adult stem cells1-8; therefore, hDPSCs could be the good candidates for autologous transplantation in tissue engineering and regenerative medicine. Along with these benefits, possessing the mesenchymal stem cells (MSC) features, such as immunolodulatory effect, make hDPSCs more valuable, even in the case of allograft transplantation6,9,10. Therefore, the primary step for using this source of stem cells is to select the best protocol for isolating hDPSCs from pulp tissue. In order to achieve this goal, it is crucial to investigate the effect of various isolation conditions on different cellular behaviors, such as their common surface markers &amp; also their differentiation capacity.
Thus, here we separate human pulp tissue from impacted third molar teeth, and then used both existing protocols based on literature, for isolating hDPSCs,11-13 i.e. enzymatic dissociation of pulp tissue (DPSC-ED) or outgrowth from tissue explants (DPSC-OG). In this regards, we tried to facilitate the isolation methods by using dental diamond disk. Then, these cells characterized in terms of stromal-associated Markers (CD73, CD90, CD105 &amp; CD44), hematopoietic/endothelial Markers (CD34, CD45 &amp; CD11b), perivascular marker, like CD146 and also STRO-1. Afterwards, these two protocols were compared based on the differentiation potency into odontoblasts by both quantitative polymerase chain reaction (QPCR) &amp; Alizarin Red Staining. QPCR were used for the assessment of the expression of the mineralization-related genes (alkaline phosphatase; ALP, matrix extracellular phosphoglycoprotein; MEPE &amp; dentin sialophosphoprotein; DSPP).14

The method described isolation and characterization of human Dental Pulp Stem Cells (hDPSCs) by using either enzymatic dissociation of pulp (DPSC-ED) or direct outgrowth of stem cells from pulp tissue explants (DPSC-OG). Then followed by in vitro comparative differentiation of both types of hDPSCs into odontoblasts.

Developing wisdom teeth are easy-accessible source of stem cells during the adulthood which could be obtained by routine orthodontic treatments. Human ...

Studying Pancreatic Cancer Stem Cell Characteristics for Developing New Treatment Strategies

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor initiation, metastasis and resistance to radio- and chemotherapy. Here we describe a specific methodology for culturing primary human pancreatic CSCs as tumor spheres in anchorage-independent conditions. Cells are grown in serum-free, non-adherent conditions in order to enrich for CSCs while their more differentiated progenies do not survive and proliferate during the initial phase following seeding of single cells. This assay can be used to estimate the percentage of CSCs present in a population of tumor cells. Both size (which can range from 35 to 250 micrometers) and number of tumor spheres formed represents CSC activity harbored in either bulk populations of cultured cancer cells or freshly harvested and digested tumors 1,2. Using this assay, we recently found that metformin selectively ablates pancreatic CSCs; a finding that was subsequently further corroborated by demonstrating diminished expression of pluripotency-associated genes/surface markers and reduced in vivo tumorigenicity of metformin-treated cells. As the final step for preclinical development we treated mice bearing established tumors with metformin and found significantly prolonged survival. Clinical studies testing the use of metformin in patients with PDAC are currently underway (e.g., NCT01210911, NCT01167738, and NCT01488552). Mechanistically, we found that metformin induces a fatal energy crisis in CSCs by enhancing reactive oxygen species (ROS) production and reducing mitochondrial transmembrane potential. In contrast, non-CSCs were not eliminated by metformin treatment, but rather underwent reversible cell cycle arrest. Therefore, our study serves as a successful example for the potential of in vitro sphere formation as a screening tool to identify compounds that potentially target CSCs, but this technique will require further in vitro and in vivo validation to eliminate false discoveries.

Pancreatic cancer stem cells (CSCs) can be expanded in vitro using the anchorage-independent sphere culture technique, which represents a powerful tool to study CSC biology and can serve as the first step to develop novel CSC-targeting therapies. Here the methodology for expanding, analyzing and targeting of pancreatic CSCs is provided.

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor ...

An Acute Retinal Model for Evaluating Blood Retinal Barrier Breach and Potential Drugs for Treatment

A low-cost, easy-to-use and powerful model system is established to evaluate potential treatments that could ameliorate blood retinal barrier breach. An inflammatory factor, histamine, is demonstrated to compromise vessel integrity in the cultured retina through positive staining of IgG outside of the blood vessels. The effects of histamine itself and those of candidate drugs for potential treatments, such as lipoxin A4, are assessed using three parameters: blood vessel leakage via IgG immunostaining, activation of M&#252;ller cells via GFAP staining and change in neuronal dendrites through staining for MAP2. Furthermore, the layered organization of the retina allows a detailed analysis of the processes of M&#252;ller and ganglion cells, such as changes in width and continuity. While the data presented is with swine retinal culture, the system is applicable to multiple species. Thus, the model provides a reliable tool to investigate the early effects of compromised retinal vessel integrity on different cell types and also to evaluate potential drug candidates for treatment.

A low-cost, easy-to-use and powerful system is established to evaluate potential treatments that could ameliorate blood retinal barrier breach induced by histamine. Blood vessel leakage, M&#252;ller cell activation and the continuity of neuronal processes are utilized to assess the damage response and its reversal with a potential drug, lipoxin A4.

A low-cost, easy-to-use and powerful model system is established to evaluate potential treatments that could ameliorate blood retinal barrier breach. An ...

Forskolin-induced Swelling in Intestinal Organoids: An In Vitro Assay for Assessing Drug Response in Cystic Fibrosis Patients

Recently-developed cystic fibrosis transmembrane conductance regulator (CFTR)-modulating drugs correct surface expression and/or function of the mutant CFTR channel in subjects with cystic fibrosis (CF). Identification of subjects that may benefit from these drugs is challenging because of the extensive heterogeneity of CFTR mutations, as well as other unknown factors that contribute to individual drug efficacy. Here, we describe a simple and relatively rapid assay for measuring individual CFTR function and response to CFTR modulators in vitro. Three dimensional (3D) epithelial organoids are grown from rectal biopsies in standard organoid medium. Once established, the organoids can be bio-banked for future analysis. For the assay, 30-80 organoids are seeded in 96-well plates in basement membrane matrix and are then exposed to drugs. One day later, the organoids are stained with calcein green, and forskolin-induced swelling is monitored by confocal live cell microscopy at 37 &#176;C. Forskolin-induced swelling is fully CFTR-dependent and is sufficiently sensitive and precise to allow for discrimination between the drug responses of individuals with different and even identical CFTR mutations. In vitro swell responses correlate with the clinical response to therapy. This assay provides a cost-effective approach for the identification of drug-responsive individuals, independent of their CFTR mutations. It may also be instrumental in the development of future CFTR modulators.

Forskolin-induced Swelling in Intestinal Organoids: An In Vitro Assay for Assessing Drug Response in Cystic Fibrosis Patients

This protocol describes an assay for measuring CFTR function and CFTR modulator responses in cultured tissue from subjects with cystic fibrosis (CF). Biopsy-derived intestinal organoids swell in a cAMP-driven fashion, a response that is defective (or strongly reduced) in CF organoids and can be restored by exposure to CFTR modulators.

Recently-developed cystic fibrosis transmembrane conductance regulator (CFTR)-modulating drugs correct surface expression and/or function of the mutant ...

Using Retinal Imaging to Study Dementia

The retina offers a unique &#8220;window&#8221; to study pathophysiological processes of dementia in the brain, as it is an extension of the central nervous system (CNS) and shares prominent similarities with the brain in terms of embryological origin, anatomical features and physiological properties.&#160; The vascular and neuronal structure in the retina can now be visualized easily and non-invasively using retinal imaging techniques, including fundus photography and optical coherence tomography (OCT), and quantified semi-automatically using computer-assisted analysis programs. Studying the associations between vascular and neuronal changes in the retina and dementia could improve our understanding of dementia and, potentially, aid in diagnosis and risk assessment.&#160; This protocol aims to describe a method of quantifying and analyzing retinal vasculature and neuronal structure, which are potentially associated with dementia. This protocol also provides examples of retinal changes in subjects with dementia, and discusses technical issues and current limitations of retinal imaging.

The retina shares prominent similarities with the brain and thus represents a unique window to study vasculature and neuronal structure in the brain non-invasively. This protocol describes a method to study dementia using retinal imaging techniques. This method can potentially aid in diagnosis and risk assessment of dementia.

The retina offers a unique &#8220;window&#8221; to study pathophysiological processes of dementia in the brain, as it is an extension of the central ...

Induction and Analysis of Oxidative Stress in Sleeping Beauty Transposon-Transfected Human Retinal Pigment Epithelial Cells

Oxidative stress plays a critical role in several degenerative diseases, including age-related macular degeneration (AMD), a pathology that affects ~30 million patients worldwide. It leads to a decrease in retinal pigment epithelium (RPE)-synthesized neuroprotective factors, e.g., pigment epithelium-derived factor (PEDF) and granulocyte-macrophage colony-stimulating factor (GM-CSF), followed by the loss of RPE cells, and eventually photoreceptor and retinal ganglion cell (RGC) death. We hypothesize that the reconstitution of the neuroprotective and neurogenic retinal environment by the subretinal transplantation of transfected RPE cells overexpressing PEDF and GM-CSF has the potential to prevent retinal degeneration by mitigating the effects of oxidative stress, inhibiting inflammation, and supporting cell survival. Using the Sleeping Beauty transposon system (SB100X) human RPE cells have been transfected with the PEDF and GM-CSF genes and shown stable gene integration, long-term gene expression, and protein secretion using qPCR, western blot, ELISA, and immunofluorescence. To confirm the functionality and the potency of the PEDF and GM-CSF secreted by the transfected RPE cells, we have developed an in vitro assay to quantify the reduction of H2O2-induced oxidative stress on RPE cells in culture. Cell protection was evaluated by analyzing cell morphology, density, intracellular level of glutathione, UCP2 gene expression, and cell viability. Both, transfected RPE cells overexpressing PEDF and/or GM-CSF and cells non-transfected but pretreated with PEDF and/or GM-CSF (commercially available or purified from transfected cells) showed significant antioxidant cell protection compared to non-treated controls. The present H2O2-model is a simple and effective approach to evaluate the antioxidant effect of factors that may be effective to treat AMD or similar neurodegenerative diseases.

Induction and Analysis of Oxidative Stress in Sleeping Beauty Transposon-Transfected Human Retinal Pigment Epithelial Cells

We present a protocol for the development and use ofan oxidative stress-model by treating retinal pigment epithelial cells with H2O2, analyzing cell morphology, viability, density, glutathione, and UCP-2 level. It is a useful model to investigate the antioxidant effect of proteins secreted by transposon-transfected cells to treat neuroretinal degeneration.

Oxidative stress plays a critical role in several degenerative diseases, including age-related macular degeneration (AMD), a pathology that affects ~30 ...

Directed Induction of Retinal Organoids from Human Pluripotent Stem Cells

Retinal cell transplantation is a promising therapeutic approach, which could restore the retinal architecture and stabilize or even improve the visual capabilities to the degenerated retina. Nevertheless, progress in cell replacement therapy presently faces the challenges of requiring an off-the-shelf source of high quality and standardized human retinas. Therefore, an easy and stable protocol is needed for the experiments. Here, we develop an optimized protocol, based on a self-organizing method with the use of exogenous molecules and reagent A as well as manual excision to generate the three-dimensional human retina organoids (RO). The human Pluripotent Stem Cells (PSCs)-derived RO expresses specific markers for photoreceptors. With the addition of COCO, a multifunctional antagonist, the differentiation efficiency of photoreceptor precursors and cones is significantly increased. The efficient use of this system, which has the benefits of cell lines and primary cells, and without the sourcing issues associated with the latter, could produce confluent retinal cells, especially photoreceptors. Thus, the differentiation of PSCs to RO provides an optimal and biorelevant platform for disease modelling, drug screening and cell transplantation.

Using a self-organizing method, we develop a protocol with the addition of COCO that could significantly increase the generation of photoreceptors.

Retinal cell transplantation is a promising therapeutic approach, which could restore the retinal architecture and stabilize or even improve the visual ...

Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases

Retinal pigment epithelial (RPE) transplantation holds great promise for the treatment of inherited and acquired retinal degenerative diseases. These conditions include retinitis pigmentosa (RP) and advanced forms of age-related macular degeneration (AMD), such as geographic atrophy (GA). Together, these disorders represent a significant proportion of currently untreatable blindness globally. These unmet medical needs have generated heightened academic interest in developing methods of RPE replacement. Among the animal models commonly utilized for preclinical testing of therapeutics, the non-human primate (NHP) is the only animal model that has a macula. As it shares this anatomical similarity with the human eye, the NHP eye is an important and appropriate preclinical animal model for the development of advanced therapy medicinal products (ATMPs) such as RPE cell therapy.
This manuscript describes a method for the submacular transplantation of an RPE monolayer, cultured on a polyethylene terephthalate (PET) cell carrier, underneath the macula onto a surgically created RPE wound in immunosuppressed NHPs. The fovea-the central avascular portion of the macula-is the site of the greatest mechanical weakness during the transplantation. Foveal trauma will occur if the initial subretinal fluid injection generates an excessive force on the retina. Hence, slow injection under perfluorocarbon liquid (PFCL) vitreous tamponade is recommended with a dual-bore subretinal injection cannula at low intraocular pressure (IOP) settings to create a retinal bleb. 
Pretreatment with an intravitreal plasminogen injection to release parafoveal RPE-photoreceptor adhesions is also advised. These combined strategies can reduce the likelihood of foveal tears when compared to conventional techniques. The NHP is a key animal model in the preclinical phase of RPE cell therapy development. This protocol addresses the technical challenges associated with the delivery of RPE cellular therapy in the NHP eye.

The non-human primate (NHP) is an ideal model for studying human retinal cellular therapeutics due to the anatomical and genetic similarities. This manuscript describes a method for submacular transplantation of retinal pigment epithelial cells in the NHP eye and strategies to prevent intraoperative complications associated with macular manipulation.

Retinal pigment epithelial (RPE) transplantation holds great promise for the treatment of inherited and acquired retinal degenerative diseases. These ...

Retinal Explant of the Adult Mouse Retina as an Ex Vivo Model for Studying Retinal Neurovascular Diseases

One of the challenges in retina research is studying the cross-talk between different retinal cells such as retinal neurons, glial cells, and vascular cells. Isolating, culturing, and sustaining retinal neurons in vitro have technical and biological limitations. Culturing retinal explants may overcome these limitations and offer a unique ex vivo model to study the cross-talk between various retinal cells with well-controlled biochemical parameters and independent of the vascular system. Moreover, retinal explants are an effective screening tool for studying novel pharmacological interventions in various retinal vascular and neurodegenerative diseases such as diabetic retinopathy. Here, we describe a detailed protocol for retinal explants' isolation and culture for an extended period. The manuscript also presents some of the technical problems during this procedure that may affect the desired outcomes and reproducibility of the retinal explant culture. The immunostaining of the retinal vessels, glial cells, and neurons demonstrated intact retinal capillaries and neuroglial cells after 2 weeks from the beginning of the retinal explant culture. This establishes retinal explants as a reliable tool for studying changes in the retinal vasculature and neuroglial cells under conditions that mimic retinal diseases such as diabetic retinopathy.

Retinal Explant of the Adult Mouse Retina as an Ex Vivo Model for Studying Retinal Neurovascular Diseases

This protocol presents and describes steps for the isolation, dissection, culturing, and staining of retinal explants obtained from an adult mouse. This method is beneficial as an ex vivo model for studying different retinal neurovascular diseases such as diabetic retinopathy.

One of the challenges in retina research is studying the cross-talk between different retinal cells such as retinal neurons, glial cells, and vascular ...