Retina criada de células-tronco embrionárias humanas

sexta-feira, maio 28, 2010

Retina Created from Human Embryonic Stem Cells

ScienceDaily (May 27, 2010) — UC Irvine scientists have created an eight-layer, early stage retina from human embryonic stem cells, the first three-dimensional tissue structure to be made from stem cells.

UCI researchers used human embryonic stem cells to create these retinal progenitor cells, which later developed into a three-dimensional tissue sheet. (Credit: Photo by UCI)

It also marks the first step toward the development of transplant-ready retinas to treat eye disorders such as retinitis pigmentosa and macular degeneration that affect millions.

"We made a complex structure consisting of many cell types," said study leader Hans Keirstead of the Reeve-Irvine Research Center and the Sue and Bill Gross Stem Cell Research Center at UCI. "This is a major advance in our quest to treat retinal disease."

In previous studies on spinal cord injury, the Keirstead group originated a method by which human embryonic stem cells could be directed to become specific cell types, a process called differentiation. Results of those studies are leading to the world's first clinical trial using a stem cell-based therapy for acute spinal cord injury.

In this study, the Keirstead team utilized the differentiation technique to create the multiple cell types necessary for the retina. The greatest challenge, Keirstead said, was in the engineering. To mimic early stage retinal development, the researchers needed to build microscopic gradients for solutions in which to bathe the stem cells to initiate specific differentiation paths.

"Creating this complex tissue is a first for the stem cell field," Keirstead said. "Dr. Gabriel Nistor in our group addressed a really interesting scientific problem with an engineering solution, showing that gradients of solutions can create complex stem cell-based tissues."

...

Read more here/Leia mais aqui: Science Daily

+++++

Journal of Neuroscience Methods

Three-dimensional early retinal progenitor 3D tissue constructs derived from human embryonic stem cells

Gabriel Nistor1, a, Magdalene J. Seiler1, a, Fengrong Yana, David Fergusona and Hans S. Keirstead, a,

a Department of Anatomy & Neurobiology, Reeve-Irvine Research Center, Sue and Bill Gross Stem Cell Research Center, University of California at Irvine, Irvine, CA, United States
Received 18 May 2009;
revised 22 April 2010;
accepted 26 April 2010.
Available online 4 May 2010.

Abstract

Purpose

To develop three-dimensional (3D) constructs of retinal pigment epithelium (RPE) and early retina progenitor cells from human embryonic stem cells (hESCs).
Methods

3D tissue constructs were developed by culturing hESC-derived neural retinal progenitors in a matrix on top of hESC-derived RPE cells in a cell culture insert. An osmolarity gradient maintained the nutrition of the 3D cell constructs. Cross-sections through hESC-derived tissue constructs were characterized by immunohistochemistry for various transcription factors and cell markers.
Results

hESC-derived tissue constructs expressed transcription factors characteristic of retinal development, such as pax6, Otx2, Chx10, retinal RAX; Brn3b (necessary for differentiation of retinal ganglion cells); and crx and nrl (role in photoreceptor development). Many cells expressed neuronal markers including nestin, beta-tubulin and microtubule-associated proteins.
Conclusions

This study shows for the first time that 3D early retinal progenitor tissue constructs can be derived from hESCs.
Keywords: Human embryonic stem cells; Retinal pigmented epithelium; Photoreceptor; Retinal progenitor differentiation; Three-dimensional culture

Abbreviations: hESC, human embryonic stem cells; RPE, retinal pigment epithelium; MAP, microtubule-associated protein; NF, neurofilament; Dkk, Dickkopf 1

+++++

Professores, pesquisadores e alunos de universidades públicas e privadas com acesso ao site CAPES/Periódicos podem ler gratuitamente este artigo do Journal of Neuroscience Methods e de mais 22.440 publicações científicas.