4 August 2014

  Researchers from the National Institutes of Health (NIH) have recently developed a technology that can accelerate stem cell formation, which simultaneously measures the expression of multiple genes and helps researchers sort cells according to cell function and developmental stages. For example, the use of this technique will help researchers to use the patient's skin cells to regenerate retinal pigment epithelial cells (RPE, the rear of the eye tissue, the site is damaged in many blinds), which will also help researchers look for personalized drug treatment. The study was published in the magazine Stem Cell Translational Medicine recently.

  RPE is a single cell layer located near the retina, which is covered with photoreceptor receptors and rod cells, RPE is essential for the photoreceptor function, a variety of diseases leading to RPE damage can lead to loss of vision and photographic function.

  Artificial induction of pluripotent stem cell technology (iPS) can promote stem cell formation. In order to verify the RPE produced by iPS cells, the researchers used microscopic and physiological function tests to ensure that the shape and function of the regenerated tissue were normal. The researchers also used quantitative RT-PCR to detect gene expression levels that reflect the progress and function of cell development. For example, in iPS cells, SOX2 gene expression is higher than mature RPE, but quantitative RT-PCR only allows researchers to measure several genes in samples synchronously. The research team developed a new multi-measurement kit based on biotechnology company Affymetrix's commercial platform. The chip can also be highly automated to measure the expression of multiple genes on RPE samples. In the chip, a small DNA fragment is bound to the beads to capture the RNA molecules produced by the genes of the cells in the RPE sample. Once obtained, RNA molecules from different genes are labeled with fluorescent labels.

  The researchers used iPS technology to induce skin tissue to generate RPE, and then detected 8 species representative of the development of marker gene expression in RPE. The team used quantitative RT-PCR to simultaneously detect the RNA levels of each gene, and then use the multi-channel chip to detect all genes simultaneously and compare the differences in gene expression between RPE and iPS cells and RPE cells produced by iPS. Compared with iPS cells, SOX2 levels of RPE produced by iPS was lower, while the RPE specific genes PAX6, RPE65, RDH5, TRPM1 and BEST1 gene were higher. Compared with the cultured RPE, the SOX2 and PAX6 genes of RPE produced by iPS were higher (the two genes were development-related markers), but the RPE-specific gene level was lower, suggesting immature state.

  The researchers said that this work suggests that automatic high-throughput techniques can be used to simultaneously measure multiple gene expression profiles of iPS-generated RPEs, which means that you can save money, increase efficiency and yield. Multi-channel chips will be applied to cell quality checks and used to screen for potentially potent compounds that will also help improve RPE-related cell therapy.

TAG: Chemical Reagents, Biomedicine