Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness in older Americans and worldwide. AMD gradually destroys sharp, central vision needed for seeing objects clearly and for common daily tasks such as reading and driving. AMD progresses with death of retinal pigment epithelium (RPE), a dark color layer of cells which nourishes the visual cells in the retina.
While some treatments can help slow its progression, there is no cure. The discovery of human induced pluripotent stem (hiPS) cells has opened a new avenue for the treatment of degenerative diseases, like AMD, by using a patient's own stem cells to generate tissues and cells for transplantation.
For transplantation to be viable in age-related macular degeneration, researchers have to first figure out how to program the naïve hiPS cells to function and possess the characteristics of the native retinal pigment epithelium, RPE, the cells that die off and lead to AMD.
The research conducted by the Georgetown scientists shows that this critical step in regenerative medicine for AMD has greatly progressed.
"This is the first time that hiPS-RPE cells have been produced with the characteristics and functioning of the RPE cells in the eye. That makes these cells promising candidates for retinal regeneration therapies in age-related macular degeneration," says the study's lead author Nady Golestaneh, Ph.D., assistant professor in GUMC's Department of Biochemistry and Molecular & Cellular Biology.
Using an established laboratory stem cell line, Golestaneh and her colleagues show that RPE generated from hiPS cells under defined conditions exhibit ion transport, membrane potential, polarized VEGF secretion and gene expression profile similar to those of a normal eye's RPE.
"This isn't ready for prime time though. We also identified some issues that need to be worked out before these cells are ready for transplantation but overall, this is a tremendous step forward in regenerative medicine," Golestaneh adds.
She explains that the hiPS-derived RPE cells show rapid telomere shortening, DNA chromosomal damage and increased p21 expression that cause cell growth arrest. This might be due to the random integration of viruses in the genome of skin fibroblasts during the reprogramming of iPS cells. Therefore, generation of viral-free iPS cells and their differentiation into RPE will be a necessary step towards implementation of these cells in clinical application, Golestaneh says.
"The next step in this research is to focus on a generation of 'safe' as well as viable hiPS-derived somatic cells," Golestaneh concludes.
Other authors on the paper include first author Maria Kokkinaki, Ph.D., Department of Biochemistry and Molecular &Cellular Biology, and Niaz Sahibzada, Ph.D., Department of Pharmacology at GUMC.
This work was funded by the National Institutes of Health. The authors report no personal financial interests related to this study.
About Georgetown University Medical Center
Georgetown University Medical Center is an internationally recognized academic medical center with a three-part mission of research, teaching and patient care (through MedStar Health). GUMC's mission is carried out with a strong emphasis on public service and a dedication to the Catholic, Jesuit principle of cura personalis -- or "care of the whole person." The Medical Center includes the School of Medicine and the School of Nursing and Health Studies, both nationally ranked, the world-renowned Georgetown Lombardi Comprehensive Cancer Center and the Biomedical Graduate Research Organization (BGRO). In fiscal year 2009-2010, GUMC accounted for 79 percent of Georgetown University's extramural research funding.
Karen Mallet | EurekAlert!
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy