Name: characterization of a novel human organotypic retinal culture technique
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Description: Watch this Scientific Journal Video about Characterization of a Novel Human Organotypic Retinal Culture Technique at JoVE.com

The authors would like to thank the generous donors of eye tissues and the team from the New Zealand National Eye Bank for their support. This work was financially supported by project grants from the Maurice and Phyllis Paykel Trust and the Auckland Medical Research Foundation (1117015). IDR&#39;s directorship is supported by the Buchanan Charitable Foundation. CK&#39;s scholarship is provided by the New Zealand Association of Optometrists Education and Research Fund (CC36812) and HHL&#39;s scholarship is provided by the Buchanan Charitable Foundation.

Human donor eye cups were obtained from the New Zealand National Eye Bank following corneal excision for transplantation and as approved by the Northern B Health and Disability Ethics Committee (NTX/06/19/CPD/AM07).
NOTE: The culture should be done in a Class II biosafety cabinet to ensure sterile tissue culture conditions. The tissues must be cultured within 24 h post-mortem to avoid significant retinal integrity loss.
<img alt="Figure 2" class="xfigimg" src="/file...

<ol>
	<li>Kolb, H., Fernandez, E., Nelson, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Facts+and+Figures+Concerning+the+Human+Retina.">Facts and Figures Concerning the Human Retina.</a> Webvision-The Organization of the Retina and Visual System. , (2005).</li><li>Gemenetzi, M., De Salvo, G., Lotery, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Central+serous+chorioretinopathy:+an+update+on+pathogenesis+and+treatment.">Central serous chorioretinopathy: an update on pathogenesis and treatment.</a> Eye. 24 (12), 1743-1756 (2010).</li><li>Buschini, E., Piras, A., Nuzzi, R., Vercelli, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age+related+macular+degeneration+and+drusen:+neuroinflammation+in+the+retina.">Age related macular degeneration and drusen: neuroinflammation in the retina.</a> Progress in Neurobiology. 95 (1), 14-25 (2011).</li><li>Chen, S. -. Y., 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=Current+concepts+regarding+developmental+mechanisms+in+diabetic+retinopathy+in+Taiwan.">Current concepts regarding developmental mechanisms in diabetic retinopathy in Taiwan.</a> Biomedicine. 6 (2), (2016).</li><li>Kaaja, R., Loukovaara, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progression+of+retinopathy+in+type+1+diabetic+women+during+pregnancy.">Progression of retinopathy in type 1 diabetic women during pregnancy.</a> Current Diabetes Reviews. 3 (2), 85-93 (2007).</li><li>Azizzadeh Pormehr, L., 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=Human+organotypic+retinal+flat-mount+culture+(HORFC)+as+a+model+for+retinitis+pigmentosa11.">Human organotypic retinal flat-mount culture (HORFC) as a model for retinitis pigmentosa11.</a> Journal of Cellular Biochemistry. 119 (8), 6775-6783 (2018).</li><li>Fernandez-Bueno, 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=Time+course+modifications+in+organotypic+culture+of+human+neuroretina.">Time course modifications in organotypic culture of human neuroretina.</a> Experimental Eye Research. 104, 26-38 (2012).</li><li>Niyadurupola, N., Sidaway, P., Osborne, A., Broadway, D. C., Sanderson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+of+human+organotypic+retinal+cultures+(HORCs)+to+study+retinal+neurodegeneration.">The development of human organotypic retinal cultures (HORCs) to study retinal neurodegeneration.</a> British Journal of Ophthalmology. 95 (5), 720-726 (2011).</li><li>Osborne, A., Hopes, M., Wright, P., Broadway, D. C., Sanderson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+organotypic+retinal+cultures+(HORCs)+as+a+chronic+experimental+model+for+investigation+of+retinal+ganglion+cell+degeneration.">Human organotypic retinal cultures (HORCs) as a chronic experimental model for investigation of retinal ganglion cell degeneration.</a> Experimental Eye Research. 143, 28-38 (2016).</li><li>Caffe, A., Visser, H., Jansen, H., Sanyal, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histotypic+differentiation+of+neonatal+mouse+retina+in+organ+culture.">Histotypic differentiation of neonatal mouse retina in organ culture.</a> Current Eye Research. 8 (10), 1083-1092 (1989).</li><li>Kaempf, S., Walter, P., Salz, A. K., Thumann, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+organotypic+culture+model+of+adult+mammalian+neurosensory+retina+in+co-culture+with+retinal+pigment+epithelium.">Novel organotypic culture model of adult mammalian neurosensory retina in co-culture with retinal pigment epithelium.</a> Journal of Neuroscience Methods. 173 (1), 47-58 (2008).</li><li>Liu, L., Cheng, S. -. H., Jiang, L. -. Z., Hansmann, G., Layer, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+pigmented+epithelium+sustains+cell+growth+and+tissue+differentiation+of+chicken+retinal+explants+in+vitro.">The pigmented epithelium sustains cell growth and tissue differentiation of chicken retinal explants in vitro.</a> Experimental Eye Research. 46 (5), 801-812 (1988).</li><li>Kuo, C., Green, C. R., Rupenthal, I. D., Mugisho, O. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Connexin43+hemichannel+block+protects+against+retinal+pigment+epithelial+cell+barrier+breakdown.">Connexin43 hemichannel block protects against retinal pigment epithelial cell barrier breakdown.</a> Acta Diabetologica. 57 (1), 13-22 (2020).</li><li>Mugisho, O. O., 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=The+inflammasome+pathway+is+amplified+and+perpetuated+in+an+autocrine+manner+through+connexin43+hemichannel+mediated+ATP+release.">The inflammasome pathway is amplified and perpetuated in an autocrine manner through connexin43 hemichannel mediated ATP release.</a> Biochimica et Biophysica Acta (BBA)-General Subjects. 1862 (3), 385-393 (2018).</li><li>Mugisho, O. O., 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=Intravitreal+pro-inflammatory+cytokines+in+non-obese+diabetic+mice:+Modelling+signs+of+diabetic+retinopathy.">Intravitreal pro-inflammatory cytokines in non-obese diabetic mice: Modelling signs of diabetic retinopathy.</a> PLoS ONE. 13 (8), 0202156 (2018).</li><li>. R&amp;D Systems, I Available from: <a target="_blank" href="https://www.rndsystems.com/protocol-types/luminex">https://www.rndsystems.com/protocol-types/luminex</a> (2020)</li><li>Nakazawa, 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=Attenuated+glial+reactions+and+photoreceptor+degeneration+after+retinal+detachment+in+mice+deficient+in+glial+fibrillary+acidic+protein+and+vimentin.">Attenuated glial reactions and photoreceptor degeneration after retinal detachment in mice deficient in glial fibrillary acidic protein and vimentin.</a> Investigative Ophthalmology, Visual Science. 48 (6), 2760-2768 (2007).</li><li>Okada, M., Matsumura, M., Ogino, N., Honda, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=M&#252;ller+cells+in+detached+human+retina+express+glial+fibrillary+acidic+protein+and+vimentin.">M&#252;ller cells in detached human retina express glial fibrillary acidic protein and vimentin.</a> Graefe's Archive for Clinical and Experimental Ophthalmology. 228 (5), 467-474 (1990).</li><li>Murali, A., Ramlogan-Steel, C. A., Andrzejewski, S., Steel, J. C., Layton, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinal+explant+culture:+A+platform+to+investigate+human+neuro-retina.">Retinal explant culture: A platform to investigate human neuro-retina.</a> Clinical &amp; Experimental Ophthalmology. 47 (2), 274-285 (2019).</li><li>Koleva-Georgieva, D. N., Sivkova, N. P., Terzieva, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serum+inflammatory+cytokines+IL-1beta,+IL-6,+TNF-alpha+and+VEGF+have+influence+on+the+development+of+diabetic+retinopathy.">Serum inflammatory cytokines IL-1beta, IL-6, TNF-alpha and VEGF have influence on the development of diabetic retinopathy.</a> Folia Medica (Plovdiv). 53 (2), 44-50 (2011).</li><li>Lee, J. -. H., 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=Cytokine+profile+of+peripheral+blood+in+type+2+diabetes+mellitus+patients+with+diabetic+retinopathy.">Cytokine profile of peripheral blood in type 2 diabetes mellitus patients with diabetic retinopathy.</a> Annals of Clinical &amp; Laboratory Science. 38 (4), 361-367 (2008).</li><li>Chorostowska-Wynimko, 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=In+vitro+angiomodulatory+activity+of+sera+from+type+2+diabetic+patients+with+background+retinopathy.">In vitro angiomodulatory activity of sera from type 2 diabetic patients with background retinopathy.</a> Journal of Physiology and Pharmacology: An Official Journal of the Polish Physiological Society. 56, 65-70 (2005).</li><li>Khalifa, R. A., Khalef, N., Moemen, L. A., Labib, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+interleukin+12+(IL-12),+interferon-inducible+protein+10+(IP-10)+and+Interleukin+18+(IL-18)+in+the+angiogenic+activity+of+diabetic+retinopathy.">The role interleukin 12 (IL-12), interferon-inducible protein 10 (IP-10) and Interleukin 18 (IL-18) in the angiogenic activity of diabetic retinopathy.</a> Research Journal of Medicine and Medical Sciences. 4, 510-514 (2009).</li><li>Zhou, J., Wang, S., Xia, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+intravitreal+inflammatory+cytokines+and+angiogenic+factors+in+proliferative+diabetic+retinopathy.">Role of intravitreal inflammatory cytokines and angiogenic factors in proliferative diabetic retinopathy.</a> Current Eye Research. 37 (5), 416-420 (2012).</li><li>Song, 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=Increased+intravitreous+interleukin-18+correlated+to+vascular+endothelial+growth+factor+in+patients+with+active+proliferative+diabetic+retinopathy.">Increased intravitreous interleukin-18 correlated to vascular endothelial growth factor in patients with active proliferative diabetic retinopathy.</a> Graefe's Archive for Clinical and Experimental Ophthalmology. 252 (8), 1229-1234 (2014).</li><li>Louie, H. H., Shome, A., Kuo, C. Y. J., Rupenthal, I. D., Green, C. R., Mugisho, O. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Connexin43+hemichannel+block+inhibits+NLRP3+inflammasome+activation+in+a+human+retinal+explant+model+of+diabetic+retinopathy.">Connexin43 hemichannel block inhibits NLRP3 inflammasome activation in a human retinal explant model of diabetic retinopathy.</a> Experimental Eye Research. , (2020).</li></ol>

HORC is currently the most clinically translatable model in preclinical retinal research. Compared to in vitro cell culture models, HORC can better represent the anatomy of the human retina in situ, through retaining the dynamic retinal cell types and their connections with neurons, vasculatures and the extracellular environment19. Compared to animal models, HORC are more advantageous in studying the pathophysiology of and designing pharmaceutical treatments for human retinal diseases due to inter...

The retina is a highly specialized ocular structure responsible for transforming incoming light energy to electric signals, which are then processed by the brain for visual perception. The human retina contains a dynamic range of cell types, highly organized in a unique lamellar structure consisting of two synaptic and three nuclei layers1 (Figure 1). Retinal homeostasis is sustained by the intricate connections between neuroretinal cells, blood vessels, nerves, connective tissues and the RPE1. Due to the sophisticated retinal anatomy and physiology, mechanisms of many retinal diseases still remain poorly understood2,3,4,5. To better study retinal diseases, HORC models have been developed6,7,8,9. Compared to animal studies and in vitro cultures, HORC models are advantageous because they retain the dynamic cellular environment and complex neurovascular interactions in situ, providing a good model for clinical translation.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/62046/62046fig01.jpg" /> 
Figure 1: Posterior ocular structures of the human eye.&#160;Anterior to posterior, the retinal layers are: nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor inner segment (IS), and photoreceptor outer layer (OS). Cells within the retina include ganglion cells (blue), amacrine cells (yellow), bipolar cells (red), horizontal cells (purple), rod photoreceptors (pink) and cone photoreceptors (green). The vitreous is located anterior to the retina. The RPE, Bruch&#39;s membrane, choroid and sclera are located posterior to the retina. Note that the&#160;image shown is only a schematic representation of the retina and the ratio of cells/retinal connectivity within each layer may not be indicative of the in vivo setting.&#160;<a href="https://www.jove.com/files/ftp_upload/62046/62046fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Previously characterized HORC protocols6,7,8,9 have involved separating the retina from the underlying RPE-choroid and sclera using a surgical trephine. However, without the support provided by these underlying structures, the translucent retina becomes flimsy, difficult to handle and tools such as forceps can easily disrupt its integrity. Furthermore, isolating retina in culture without the RPE has been shown to cause ganglion cell apoptosis and photoreceptor degeneration10,11,12. Thus, an alternative HORC protocol that minimizes the loss of retinal integrity and better mimics the in vivo environment would be useful. This is particularly important when studying retinal disease mechanisms, as physical injury during explant handling could introduce artifacts. Therefore, the aim of this study was to develop a novel HORC model that includes the RPE-choroid and sclera in order to protect retinal integrity during explant handling and culture.
In order to achieve this aim, retinal explants &#34;sandwiched&#34; between the residual vitreous and the underlying RPE-choroid and sclera were extracted. In the sandwich explants, the vitreous weighs down the retina to prevent retinal detachment and folding, whereas the tough, fibrous sclera acts as both a scaffold for structural support and a contact point for forceps. Moreover, animal models have shown that retaining the RPE in culture can prevent retinal degeneration and glial proliferation, a response of M&#252;ller cells to danger signals such as hypoxia and inflammation10,11,12.
To characterize the model, sandwich retinal explants were stained with Hematoxylin and Eosin (H&#38;E) to assess anatomical structures and immunohistochemistry (IHC) was performed, labeling explants with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL, an apoptotic cell marker), glial fibrillary acidic protein (GFAP, a retinal inflammation and M&#252;ller cell activation marker), and vimentin, a marker of M&#252;ller cell integrity. To determine whether this model can be induced to develop molecular disease signs, the explants were exposed to high glucose (HG) with pro-inflammatory cytokines (Cyt), interleukin-1&#946; (IL-1&#946;) and tumor necrosis factor-&#945; (TNF-&#945;), a culturing environment that has been shown to mimic diabetic retinopathy (DR) in both cell and animal disease models13,14,15. Luminex&#160;assays were used in the DR model to measure cytokines&#160;released into the culture medium.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Disposable Biopsy Punches (5 mm)</td>
			<td>Integra York PA Inc., USA</td>
			<td>21909-142</td>
			<td>Referred as surgical trephines 
			in this article</td>
		</tr>
		<tr>
			<td>Human Recombinant IL-1&#946;</td>
			<td>Peprotech, USA</td>
			<td>200-01B</td>
			<td>Working concentration: 10 ng/mL</td>
		</tr>
		<tr>
			<td>Human Recombinant&#160; TNF-a</td>
			<td>Peprotech, USA</td>
			<td>300-01A</td>
			<td>Working concentration: 10 ng/mL</td>
		</tr>
		<tr>
			<td>DAPI (1 &#181;g/mL)</td>
			<td>Sigma Aldrich, Germany</td>
			<td>#D9542</td>
			<td>Nuclear stain. Working dilution 1:1000</td>
		</tr>
		<tr>
			<td>DMEM/F-12, GlutaMAX supplement</td>
			<td>Gibco, Thermofisher, Scientific Inc., USA</td>
			<td>10565018</td>
			<td>Dulbecco&#8217;s Modified Eagle Medium nutrient mixture F-12 containing a 1&#215; antibiotics and antimycotics mixture (AA, 100&#215; stock)</td>
		</tr>
		<tr>
			<td>Fine Scissors - Sharp-Blunt</td>
			<td>Fine Science Tools (F.S.T)</td>
			<td>14028-10</td>
			<td>Tips: Sharp-Blunt, Cutting Edge: 27mm, Length: 10cm, Alloy/Material: Stainless Steel, Serrated: No, Tip Shape: Straight</td>
		</tr>
		<tr>
			<td>Graefe Forceps</td>
			<td>Fine Science Tools (F.S.T)</td>
			<td>11050-10</td>
			<td>Length:10cm, Tip shape: Straight, Tips: Serrated, Tip Width: 0.8mm, Tip Dimensions:0.8 x 0.7mm, Alloy/Materials: Stainless Steel</td>
		</tr>
		<tr>
			<td>Mouse monoclonal GFAP-Cy3</td>
			<td>Sigma Aldrich, Germany</td>
			<td>#C9205</td>
			<td>Primary antibody conjugated to Cy3. Working dilution 1:1000.</td>
		</tr>
		<tr>
			<td>Mouse monoclonal Vimentin-Cy3</td>
			<td>Sigma Aldrich, Germany</td>
			<td>#C9080</td>
			<td>Primary antibody conjugated to Cy3. Working dilution 1:50.</td>
		</tr>
		<tr>
			<td>Rabbit polyclonal TUNEL (In Situ Cell Death Detection Kit, Fluorescein)</td>
			<td>Sigma Aldrich, Germany</td>
			<td>#11684795910</td>
			<td>Primary antibody conjugated to Fluorescein-dUTP. Working dilution 1:10 with enzyme-buffer solution.</td>
		</tr>
	</tbody>
</table>

characterization of a novel human organotypic retinal culture technique

Previous human organotypic retinal culture (HORC) models have utilized detached retinas; however, without the structural support conferred by retinal pigment epithelium-choroid (RPE-choroid) and sclera, the integrity of the fragile retina can easily be compromised. The aim of this study was to develop a novel HORC model that contains the retina, RPE-choroid and sclera to maintain retinal integrity when culturing retinal explants.
After cutting circumferentially along the limbus to remove iris and lens, four deep incisions were made to flatten the eyecup. In contrast to previous HORC protocols, a trephine was used to cut through not only the retina but also the RPE-choroid and sclera. The resultant triple-layered explants were cultured for 72 h. Hematoxylin and Eosin staining (H&#38;E) was used to assess anatomical structures and retinal explants were further characterized by immunohistochemistry (IHC) for apoptosis, M&#252;ller cell integrity and retinal inflammation. To confirm the possibility of disease induction, explants were exposed to high glucose (HG) and pro-inflammatory cytokines (Cyt), to mimic diabetic retinopathy (DR). The Luminex magnetic bead assay was used to measure DR-related cytokines released into the culture medium.
H&#38;E staining revealed distinct retinal lamellae and compact nuclei in retinal explants with the underlying RPE-choroid and sclera, while retinas without the underlying structures exhibited reduced thickness and severe nuclei loss. IHC results indicated absence of apoptosis and retinal inflammation as well as preserved M&#252;ller cell integrity. The Luminex&#160;assays showed significantly increased secretion of DR-associated pro-inflammatory cytokines in retinal explants exposed to HG + Cyt relative to baseline levels at 24 h.
We successfully developed and characterized a novel HORC protocol in which retinal integrity was preserved without apoptosis or retinal inflammation. Moreover, the induced secretion of DR-associated pro-inflammatory biomarkers when exposing retinal explants to HG + Cyt suggests that this model could be used for clinically translatable retinal disease studies.

Retinal integrity was preserved in this HORC model. Retinal integrity was preserved in the cultured sandwich retinal explants but was lost in the retina cultured without adjacent structures. H&#38;E was conducted to examine the structural integrity of sectioned sandwich retinal explants after 72 h in culture. The sandwich retinal explants showed preserved integrity and a distinct lamellae structure from GCL to ONL with compact nuclei in INL and ONL (F...

Watch this Scientific Journal Video about Characterization of a Novel Human Organotypic Retinal Culture Technique at JoVE.com

Characterization of a Novel Human Organotypic Retinal Culture Technique

This study aims to develop a novel human organotypic retinal culture (HORC) model that prevents compromising retinal integrity during explant handling. This is achieved by culturing the retina with the overlying vitreous and the underlying retinal pigment&#160;epithelium-choroid (RPE-choroid) and sclera.

Previous human organotypic retinal culture (HORC) models have utilized detached retinas; however, without the structural support conferred by retinal ...

This technique preserves all retinal layers and cell types in situ, making it more clinically relevant compared to animal and in vitro models. The main advantage of this protocol is that it minimizes retinal integrity disruption during tissue handling, which is essential when comparing healthy and diseased retina. Retinal diseases can be mimicked by culturing the tissue under specific conditions.This allows for testing of new drug therapies. The dissection and sample collection procedures are complex. Therefore, visual demonstration is critical to help the readers understand the written protocol and conduct the procedure successfully.Demonstrating the procedure will be Charisse Kuo, a second year PhD student from my laboratory. Prepare the culture medium containing Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12 and a one times antibiotics and antimycotics mixture. First, place 500 microliters of medium in a 24-well plate and equilibrate it in a humidified incubator at 37 degrees Celsius and 5%carbon dioxide.Having the media ready prior to explant extraction avoids dislodging of the retina upon subsequent addition. For extracting retinal explants, begin by placing the eyecup on a Petri dish with the iris and lens facing upwards and the ONH contacting the Petri dish. Hold the eyecup steady at the limbus using forceps and detach the iris and lens by making small cuts circumferentially along the outer edge of the limbus.Remove the iris and lens carefully, making sure to avoid disturbing the retina. Identify the ONH using a bright white light source and incise at the four quadrants towards the ONH rotating the Petri dish for easier handling. Spread and flatten the eyecup carefully.Apply the forceps to the sclera instead of the retina to avoid disrupting the retinal integrity. Remove the plate containing the prepared media from the incubator. Place a surgical trephine on the retina in a region without retinal folds and press hard to penetrate the sclera, which should generate a cracking sound as you break through the Petri dish.Rotate the trephine to ensure the sclera has been penetrated fully such that the retinal explant is now separated from the rest of the sample. Apply the forceps at the sclera and transfer the sandwich retinal explant to the culture medium. Culture the collected sandwich retinal explants at 37 degrees Celsius for up to 72 hours in a humidified 5%carbon dioxide incubator.Hematoxylin and eosin staining showed that the sandwich retinal explants preserved integrity and a distinct lamellae structure from the GCL to the ONL with compact nuclei in the inner and outer nuclear layers. Disrupted retinal integrity was found at the edges of the same sample where the retina had detached from the underlying RPE choroid and sclera showing reduced retinal thickness and loss of nuclei in the INL and ONL. No TUNEL-positive cell nuclei, which marks cellular apoptosis, were found in retinal explants cultured in basal conditions, demonstrating sustained cellular vitality even after 72 hours.GFAP labeling was restricted to the GCL and the IPL without glial fibrosis, a sign of pathology which would be identified as extended expression of GFAP into the ONL. Vimentin was highly expressed from the ganglion cell layer to the outer nuclear layer, showing preserved Mueller cell integrity as seen in normal retinal tissues. Luminex magnetic assay showed that the IL-18, VEGF, IL-6, and IL-8 levels increased significantly above baseline in the sandwich retinal explant cultures in high glucose and pro-inflammatory cytokines after 24 hours.After 72 hours, IL-18 and VEGF levels remained significantly increased, but no significant difference was found in IL-6 and IL-8 levels. When performing this procedure, leave sufficient residual vitreous, which will weigh the retina down so that it does not detach from the RP choroid and float in the culture media. The cultured retina can be further characterized using immunohistochemistry and histology, while the inflammatory cytokines released into the cultured medium can be measured using a Luminex magnetic assay.This model is more clinically translatable compared to animal and in vitro models, which renders more suitable for testing the efficacy of novel therapeutic drugs for retinal diseases.

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We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which works especially well with poor mask fit.
Can not intubate, can not ventilate" (CICV) is a potentially life threatening situation. In this video we present a simulation of the technique we used in a case of CICV where oxygenation and ventilation were maintained by inserting an endotracheal tube (ETT) nasally down to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.
A 13 year old patient was taken to the operating room for incision and drainage of a neck abcess and direct laryngobronchoscopy. After preoxygenation, anesthesia was induced intravenously. Mask ventilation was found to be extremely difficult because of the swelling of the soft tissue. The face mask could not fit properly on the face due to significant facial swelling as well. A direct laryngoscopy was attempted with no visualization of the larynx. Oxygen saturation was difficult to maintain, with saturations falling to 80%. In order to oxygenate and ventilate the patient, an endotracheal tube was then inserted nasally after nasal spray with nasal decongestant and lubricant. The tube was pushed gently and blindly into the hypopharynx. The mouth and nose of the patient were sealed by hand and positive pressure ventilation was possible with 100% O2 with good oxygen saturation during that period of time. Once the patient was stable and well sedated, a rigid bronchoscope was introduced by the otolaryngologist showing extensive subglottic and epiglottic edema, and a mass effect from the abscess, contributing to the airway compromise. The airway was secured with an ETT tube by the otolaryngologist.This video will show a simulation of the technique on a patient undergoing general anesthesia for dental restorations.

We describe a technique to maintain oxygenation and ventilation using an endotracheal tube inserted nasally to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which ...

A Novel Capsulorhexis Technique Using Shearing Forces with Cystotome

Purpose:
To demonstrate a capsulorhexis technique using predominantly shearing forces with a cystotome on a virtual reality simulator and on a human eye.
Method:
Our technique involves creating the initial anterior capsular tear with a cystotome to raise a flap. The flap left unfolded on the lens surface. The cystotome tip is tilted horizontally and is engaged on the flap near the leading edge of the tear. The cystotome is moved in a circular fashion to direct the vector forces. The loose flap is constantly swept towards the centre so that it does not obscure the view on the tearing edge.
Results:
Our technique has the advantage of reducing corneal wound distortion and subsequent anterior chamber collapse. The capsulorhexis flap is moved away from the tear leading edge allowing better visualisation of the direction of tear. This technique offers superior control of the capsulorhexis by allowing the surgeon to change the direction of the tear to achieve the desired capsulorhexis size.
Conclusions:
The EYESI Surgical Simulator is a realistic training platform for surgeons to practice complex capsulorhexis techniques. The shearing forces technique is a suitable alternative and in some cases a far better technique in achieving the desired capsulorhexis.

This video demonstrates a novel capsulorhexis technique in modern cataract surgery. Capsulorhexis is the most difficult and important part of phacoemulsification surgery.

Purpose:
To demonstrate a capsulorhexis technique using predominantly shearing forces with a cystotome on a virtual reality simulator and on a human eye....

Corneal Confocal Microscopy: A Novel Non-invasive Technique to Quantify Small Fibre Pathology in Peripheral Neuropathies

The accurate quantification of peripheral neuropathy is important to define at risk patients, anticipate deterioration, and assess new therapies. Conventional methods assess neurological deficits and electrophysiology and quantitative sensory testing quantifies functional alterations to detect neuropathy. However, the earliest damage appears to be to the small fibres and yet these tests primarily assess large fibre dysfunction and have a limited ability to demonstrate regeneration and repair. The only techniques which allow a direct examination of unmyelinated nerve fibre damage and repair are sural nerve biopsy with electron microscopy and skin-punch biopsy. However, both are invasive procedures and require lengthy laboratory procedures and considerable expertise. Corneal Confocal microscopy is a non-invasive clinical technique which provides in-vivo imaging of corneal nerve fibres. We have demonstrated early nerve damage, which precedes loss of intraepidermal nerve fibres in skin biopsies together with stratification of neuropathic severity and repair following pancreas transplantation in diabetic patients. We have also demonstrated nerve damage in idiopathic small fibre neuropathy and Fabry's disease.

Corneal Confocal microscopy is a non-invasive clinical technique which may be used to quantify C fibre damage to diagnose and stratify patients with increasing neuropathic severity.

The accurate quantification of peripheral neuropathy is important to define at risk patients, anticipate deterioration, and assess new therapies. ...

A Novel Technique of Rescuing Capsulorhexis Radial Tear-out using a Cystotome

Part 1 : Purpose: To demonstrate a capsulorhexis radial tear out rescue technique using a cystotome on a virtual reality cataract surgery simulator and in a human eye. Part 2 : Method: Steps: When a capsulorhexis begins to veer radially towards the periphery beyond the pupillary margin the following steps should be applied without delay. 2.1) Stop further capsulorhexis manoeuvre and reassess the situation. 2.2) Fill the anterior chamber with ophthalmic viscosurgical device (OVD). We recommend mounting the cystotome to a syringe containing OVD so that the anterior chamber can be reinflated rapidly. 2.3) The capsulorhexis flap is then left unfolded on the lens surface. 2.4) The cystotome tip is tilted horizontally to avoid cutting or puncturing the flap and is engaged on the flap near the leading edge of the tear but not too close to the point of tear. 2.5) Gently push or pull the leading edge of tear opposite to the direction of tear. 2.6) The leading tearing edge will start to do a 'U-Turn'. Maintain the tension on the flap until the tearing edge returns to the desired trajectory. Part 3 : Results: Using our technique, a surgeon can respond instantly to radial tear out without having to change surgical instruments. Changing surgical instruments at this critical stage runs a risk of further radial tear due to sudden shallowing of anterior chamber as a result of forward pressure from the vitreous. Our technique also has the advantage of reducing corneal wound distortion and subsequent anterior chamber collapse. Part 4 : Discussion The EYESI Surgical Simulator is a realistic training platform for surgeons to practice complex capsulorhexis tear-out techniques. Capsulorhexis is the most important and complex part of phacoemulsification and endocapsular intraocular lens implantation procedure. A successful cataract surgery depends on achieving a good capsulorhexis. During capsulorhexis, surgeons may face a challenging situation like a capsulorhexis radial tear-out. A surgeon must learn to tackle the problem promptly without making the situation worse. Some other methods of rescuing the situation have been described using a capsulorhexis forceps. However, we believe our method is quicker, more effective and easier to manipulate as demonstrated on the EYESi surgical simulator and on a human eye. Acknowledgments: List acknowledgements and funding sources. We would like to thank Dr. Wael El Gendy, for video clip. Disclosures: describe potential conflicting interests or state We have nothing to disclose. References: 1. Brian C. Little, Jennifer H. Smith, Mark Packer. J Cataract Refract Surg 2006; 32:1420 1422, Issue-9. 2. Neuhann T. Theorie und Operationstechnik der Kapsulorhexis. Klin Monatsbl Augenheilkd. 1987; 1990: 542-545. 3. Gimbel HV, Neuhann T. Development, advantages and methods of the continuous circular capsulorhexis technique. J Cataract Refract Surg. 1990; 16: 31-37. 4. Gimbel HV, Neuhann T. Continuous curvilinear capsulorhexis. (letter) J Cataract Refract Sur. 1991; 17: 110-111.

Capsulorhexis is an important step in phacoemulsification surgery. A surgeon creates a continous curvilinear tear on the anterior lens capsule by controlling the tearing vector forces. A peripherally extended tear is a serious complication. This video demonstrates a novel technique of rescuing capsular radial tear out using a cystotome.

Part 1 : Purpose:   To demonstrate a capsulorhexis radial tear out rescue technique using a cystotome on a virtual reality cataract surgery simulator and ...

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 ...

A Brain Tumor/Organotypic Slice Co-culture System for Studying Tumor Microenvironment and Targeted Drug Therapies

Brain tumors are a major cause of cancer-related morbidity and mortality. Developing new therapeutics for these cancers is difficult, as many of these tumors are not easily grown in standard culture conditions. Neurosphere cultures under serum-free conditions and orthotopic xenografts have expanded the range of tumors that can be maintained. However, many types of brain tumors remain difficult to propagate or study. This is particularly true for pediatric brain tumors such as pilocytic astrocytomas and medulloblastomas. This protocol describes a system that allows primary human brain tumors to be grown in culture. This quantitative assay can be used to investigate the effect of microenvironment on tumor growth, and to test new drug therapies. This protocol describes a system where fluorescently labeled brain tumor cells are grown on an organotypic brain slice from a juvenile mouse. The response of tumor cells to drug treatments can be studied in this assay, by analyzing changes in the number of cells on the slice over time. In addition, this system can address the nature of the microenvironment that normally fosters growth of brain tumors. This brain tumor organotypic slice co-culture assay provides a propitious system for testing new drugs on human tumor cells within a brain microenvironment.

Many types of human brain tumors are localized to specific regions within the brain and are difficult to grow in culture. This protocol addresses the role of tumor microenvironment and investigates new drug treatments by analyzing fluorescent primary brain tumor cells growing in an organotypic mouse brain slice. &#160;

Brain tumors are a major cause of cancer-related morbidity and mortality. Developing new therapeutics for these cancers is difficult, as many of these ...

Modeling the Early Steps of Ovarian Cancer Dissemination in an Organotypic Culture of the Human Peritoneal Cavity

The pattern of ovarian cancer metastasis is markedly different from that of most other epithelial tumors, because it rarely spreads hematogenously. Instead, ovarian cancer cells exfoliated from the primary tumor are carried by peritoneal fluid to metastatic sites within the peritoneal cavity. These sites, most notably the abdominal peritoneum and omentum, are organs covered by a mesothelium-lined surface. To investigate the processes of ovarian cancer dissemination, we assembled a complex three-dimensional culture system that reconstructs the lining of the peritoneal cavity in vitro. Primary human fibroblasts and mesothelial cells were isolated from human omentum. The fibroblasts were then mixed with extracellular matrix and covered with a layer of the primary human mesothelial cells to mimic the peritoneal and omental surfaces encountered by metastasizing ovarian cancer cells. The resulting organotypic model is, as shown, used to examine the early steps of ovarian cancer dissemination, including cancer cell adhesion, invasion, and proliferation. This model has been used in a number of studies to investigate the role of the microenvironment (cellular and acellular) in early ovarian cancer dissemination. It has also been successfully adapted to high throughput screening and used to identify and test inhibitors of ovarian cancer metastasis.

Here, we present a protocol to construct a three-dimensional in vitro model of the lining of the peritoneal cavity, composed of primary human mesothelial cells and fibroblasts layered with extracellular matrix, as a tool to investigate ovarian cancer cell adhesion, invasion, and proliferation.

The pattern of ovarian cancer metastasis is markedly different from that of most other epithelial tumors, because it rarely spreads hematogenously. ...

A Human Glioblastoma Organotypic Slice Culture Model for Study of Tumor Cell Migration and Patient-specific Effects of Anti-Invasive Drugs

Glioblastoma (GBM) continues to carry an extremely poor clinical prognosis despite surgical, chemotherapeutic, and radiation therapy. Progressive tumor invasion into surrounding brain parenchyma represents an enduring therapeutic challenge. To develop anti-migration therapies for GBM, model systems that provide a physiologically relevant background for controlled experimentation are essential. Here, we present a protocol for generating slice cultures from human GBM tissue obtained during surgical resection. These cultures allow for ex vivo experimentation without passaging through animal xenografts or single cell cultures. Further, we describe the use of time-lapse laser scanning confocal microscopy in conjunction with cell tracking to quantitatively study the migratory behavior of tumor cells and associated response to therapeutics. Slices are reproducibly generated within 90 min of surgical tissue acquisition. Retrovirally-mediated fluorescent cell labeling, confocal imaging, and tumor cell migration analyses are subsequently completed within two weeks of culture. We have successfully used these slice cultures to uncover genetic factors associated with increased migratory behavior in human GBM. Further, we have validated the model&#39;s ability to detect patient-specific variation in response to anti-migration therapies. Moving forward, human GBM slice cultures are an attractive platform for rapid ex vivo assessment of tumor sensitivity to therapeutic agents, in order to advance personalized neuro-oncologic therapy.

Current ex vivo models of glioblastoma (GBM) are not optimized for physiologically relevant study of human tumor invasion. Here, we present a protocol for generation and maintenance of organotypic slice cultures from fresh human GBM tissue. A description of time-lapse microscopy and quantitative cell migration analysis techniques is provided.

Glioblastoma (GBM) continues to carry an extremely poor clinical prognosis despite surgical, chemotherapeutic, and radiation therapy. Progressive tumor ...

A Detailed Protocol for Perspiration Monitoring Using a Novel, Small, Wireless Device

Perspiration monitoring can be utilized for the detection of certain diseases, such as thermoregulation and mental disorders, particularly when the patients are unaware of such disorders or are having difficulty expressing their symptoms. Until now, several devices for perspiration monitoring have been developed; however, such devices tend to have a relatively large exterior, considerable power consumption, and/or less sensitivity.
Recently, we developed a small, wireless device for perspiration monitoring. The device consists of a temperature/relative humidity (T/RH) sensor, battery-driven small data logger, and silica gel as a desiccant in a small cylindrical exterior. The T/RH sensor is placed between the detection windows (through which the water vapor from the skin enters) and the silica gel. The underlying principle of the perspiration monitoring device is based on Fick&#39;s law of diffusion, which means that water vapor flux from the skin to the silica gel (i.e.&#160;transepidermal water loss and perspiration) can be captured by change in humidity at the T/RH sensor. In addition, a baseline subtraction method was adopted to distinguish perspiration and transepidermal water loss.
As shown in the previous report, the developed device can monitor the perspiration at any sites of the body in an easy, wireless manner. However, detailed methods of how to use the device have not been disclosed yet. In this article, therefore, we would like to show the point-by-point tutorials of how to use the device for perspiration monitoring, by showing the sympathetic activity test with the sympathetic skin response monitoring as an example.

Recently, we developed a small wireless device for perspiration monitoring. In this article, we present detailed protocols on how to use the device for perspiration monitoring with an example of the sympathetic activity test.

Perspiration monitoring can be utilized for the detection of certain diseases, such as thermoregulation and mental disorders, particularly when the ...

Minimally Invasive Muscle Embedding (MIME) - A Novel Experimental Technique to Facilitate Donor-Cell-Mediated Myogenesis

Skeletal muscle possesses regenerative capacity due to tissue-resident, muscle-fiber-generating (myogenic) satellite cells (SCs), which can form new muscle fibers under the right conditions. Although SCs can be harvested from muscle tissue and cultured in vitro, the resulting myoblast cells are not very effective in promoting myogenesis when transplanted into host muscle. Surgically exposing the host muscle and grafting segments of donor muscle tissue, or the isolated muscle fibers with their SCs onto host muscle, promotes better myogenesis compared to myoblast transplantation. We have developed a novel technique that we call Minimally Invasive Muscle Embedding (MIME). MIME involves passing a surgical needle through the host muscle, drawing a piece of donor muscle tissue through the needle track, and then leaving the donor tissue embedded in the host muscle so that it may act as a source of SCs for the host muscle. Here we describe in detail the steps involved in performing MIME in an immunodeficient mouse model that expresses a green fluorescent protein (GFP) in all of its cells. Immunodeficiency in the host mouse reduces the risk of immune rejection of the donor tissue, and GFP expression enables easy identification of the host muscle fibers (GFP+) and donor-cell-derived muscle fibers (GFP-). Our pilot data suggest that MIME can be used to implant an extensor digitorum longus (EDL) muscle from a donor mouse into the tibialis anterior (TA) muscle of a host mouse. Our data also suggest that when a myotoxin (barium chloride, BaCl2) is injected into the host muscle after MIME, there is evidence of donor-cell-derived myogenesis in the host muscle, with approximately 5%, 26%, 26% and 43% of the fibers in a single host TA muscle showing no host contribution, minimal host contribution, moderate host contribution, and maximal host contribution, respectively.

Minimally Invasive Muscle Embedding MIME - A Novel Experimental Technique to Facilitate Donor-Cell-Mediated Myogenesis

We describe a novel experimental technique that we call Minimally Invasive Muscle Embedding (MIME), which is based on the evidence that skeletal muscle tissue contains viable myogenic cells that can facilitate donor-cell-mediated myogenesis when implanted into a host muscle.

Skeletal muscle possesses regenerative capacity due to tissue-resident, muscle-fiber-generating (myogenic) satellite cells (SCs), which can form new ...