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Archive - Jul 2, 2015

Microglia Cells Accelerate Damage from Retinitis Pigmentosa, Other Blinding Eye Diseases; Finding May Suggest Entirely New Therapeutic Strategies; Targeting Microglia May Complement Gene Therapy for RP

Spider-like cells inside the brain, spinal cord, and eye hunt for invaders, capturing and then devouring them. These cells, called microglia (image), often play a beneficial role by helping to clear trash and protect the central nervous system against infection. But a new study by researchers at the National Eye Institute (NEI) shows that they also accelerate damage wrought by blinding eye disorders, such as retinitis pigmentosa. The NEI is part of the National Institutes of Health (NIH). "These findings are important because they suggest that microglia may provide a target for entirely new therapeutic strategies aimed at halting blinding eye diseases of the retina," said NEI Director, Paul A. Sieving, M.D. "New targets create untapped opportunities for preventing disease-related damage to the eye, and preserving vision for as long as possible." The findings were published online on July 2, 2015 in an open-access article in EMBO Molecular Medicine. The article is titled “Microglial Phagocytosis of Living Photoreceptors Contributes to Inherited Retinal Degeneration." Retinitis pigmentosa, an inherited disorder that affects approximately 1 in 4,000 people, damages the retina, the light-sensitive tissue at the back of the eye. Research has shown links between retinitis pigmentosa and several mutations in genes for photoreceptors, the cells in the retina that convert light into electrical signals that are sent to the brain via the optic nerve. In the early stages of the disease, rod photoreceptors, which enable us to see in low light, are lost, causing night blindness. As the disease progresses, cone photoreceptors, which are needed for sharp vision and seeing colors, can also die off, eventually leading to complete blindness.

ASHG Honors Leonid Krugylak with 2015 Curt Stern Early-Career Geneticist Award

The American Society of Human Genetics (ASHG) has named Leonid Kruglyak (photo), Ph.D., Professor of Human Genetics and Professor of Biological Chemistry at the David Geffen School of Medicine at UCLA, and Investigator of the Howard Hughes Medical Institute (HHMI), as the 2015 recipient of the Curt Stern Award (http://www.ashg.org/pages/awards_overview.shtml#stern). This annual award, named for the late pioneering geneticist Curt Stern, Ph.D., recognizes genetics and genomics researchers who have made significant scientific contributions during the past decade. ASHG will present the award, which will include a crystal plaque and cash prize, on Friday, October 9, during the organization’s 65th Annual Meeting (http://www.ashg.org/2015meeting/) in Baltimore, Maryland. Throughout his career, Dr. Kruglyak has focused on understanding how a person’s genes interact with each other and the environment to influence his or her traits, such as appearance, behavior, and disease susceptibility. As a postdoctoral researcher in the mid-1990s, he developed algorithms for the computer program GENEHUNTER, which allowed complex calculations of genetic linkage to be carried out on personal computers and quickly became a standard tool for mapping complex disease genes. Over the next decade, he authored key papers predicting the number of genetic markers required for genome-wide association studies in humans, and pioneered the field of genetics of global gene expression (now known as eQTL analysis). In recent years, Dr. Kruglyak’s laboratory has focused on using genomic technology to establish the yeast species Saccharomyces cerevisiae and the roundworm Caenorhabditis elegans as powerful model organisms for the study of complex genetic variation. A member of ASHG since 1999 and Fellow of the American Association for the Advancement of Science since 2007, Dr.

Latent Cytomegalovirus Infection Shortens Telomeres and Decreases Longevity by Microcompetition; Microcompetition Theory Suggests New Therapeutic Avenues for Diseases and Also Life Style Changes to Increase Healthy Longevity

Molecular, cellular, and clinical changes that arise from an infection with a latent virus can result in shortened telomeres and a decrease in longevity. The telomeres (image) are repetitive DNA sequences at each end of each of our chromosomes. Studies show that in every cell division, the telomere is shortened. As a result, the telomere limits the cell to a fixed number of divisions and a limited life span. An essential part of human cells, telomeres affect how our cells age - as people with longer telomeres tend to live longer lives. Surprisingly, people who are infected with a latent virus, that is, an asymptomatic virus, have shorter telomeres. This is an important observation and a great mystery. Is the virus causing the telomere shortening, and how? And if this is the case, what does it mean in terms of the relationship between the latent viruses and longevity? Now, an article titled “The Latent Cytomegalovirus Decreases Telomere Length by Microcompetition” by Dr. Hanan Polansky and Dr. Adrian Javaherian, published online on June 27, 2015 in the open-access journal Open Medicine by De Gruyter Open, provides some answers to these questions. As it turns out, a certain gene, called telomere repeat binding factor 2 (Terf2), belongs to a complex of six telomere-associated proteins, termed shelterin. The protein produced by the Terf2 gene protects the chromosome ends of the DNA from damage, and controls telomere maintenance by the telomerase enzyme. When does a cell produce the Terf2 protein? It does so after receiving a signal that tells a transcription factor called GABP to bind the Terf2 gene. One can think of GABP as a finger that pushes the “ON” button on the Terf2 gene. Now, consider a case where a latent virus called cytomegalovirus (CMV) infects the cell.