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Archive - Jul 26, 2019

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CRISPR Activation Screen Identifies Genes That Protect Cells from Zika Virus Infection and Also Prevent Death of Zika-Infected Cells

The Zika virus (image) has affected over 60 million people, mostly in South America. It has potentially devastating consequences for pregnant women and their unborn children, many of whom are born with severe microcephaly and other developmental and neurological abnormalities. There is currently no vaccine or specific treatment for the virus. A new Tel Aviv University (TAU) study uses a genetic screen to identify genes that protect cells from Zika viral infection. The research, led by Dr. Ella H. Sklan of TAU's Sackler School of Medicine, was published online on May 29, 2019 in the Journal of Virology. It may one day lead to the development of a treatment for the Zika virus and other infections. The article is titled “A CRISPR Activation Screen Identifies Genes Protecting from Zika Virus Infection.” The study was based on a modification of the CRISPR-Cas9 gene-editing technique. CRISPR-Cas9 is a naturally occurring bacterial genome editing system that has been adapted to gene editing in mammalian cells. The system is based on the bacterial enzyme Cas9, which can locate and modify specific locations along the human genome. A modification of this system, known as CRISPR activation, is accomplished by genetically changing Cas9 in a way that enables the expression of specific genes in their original DNA locations. "CRISPR activation can be used to identify genes protecting against viral infection," Dr. Sklan says. "We used this adapted system to activate every gene in the genome in cultured cells. We then infected the cells with the Zika virus. While most cells die following the infection, some survived due to the over-expression of some protective genes. We then used next-generation sequencing and bioinformatic analysis to identify a number of genes that enabled survival, focusing on one of these genes called IFI6.

How Pufferfish Developed Its Unusual Spines

Pufferfish are known for their strange and extreme skin ornaments, but how they came to possess the spiky skin structures known as spines has largely remained a mystery. Now, researchers have identified the genes responsible for the evolution and development of pufferfish spines in a study published online on July 25, 2019 in iScience. The open-access article is titled “Evolution and Developmental Diversity of Skin Spines in Pufferfishes.” It turns out that the process is pretty similar to how other vertebrates get their hair or feathers--and might have allowed the pufferfish to fill unique ecological niches. "Pufferfish are some of the strangest fish in the ocean, particularly because they have a reduced skeleton, beak-like dentition and they form spines instead of scales--not everywhere, but just in certain patches around the body," says corresponding author Gareth Fraser (@garethjfraser), PhD, an Assistant Professor at the University of Florida. Dr. Fraser and his team followed the development of pufferfish spines in embryos. While the scientists had initially hypothesized that the spines formed from scales--that the pufferfish lost its scale component but retained the spine--they found that the spines are developmentally unique from scales. They also found that the development of pufferfish spines relies on the same network of genes that are commonly expressed within feathers and hairs of other vertebrate animals. "It just blows me away that regardless of how evolutionarily-different skin structures in animals are, they still use the same collection of genes during development," Dr. Fraser says.

Vitamin D Supplementation May Slow Diabetes Progression, New Study Suggests

Vitamin D supplementation may slow the progression of type 2 diabetes in newly diagnosed patients and those with prediabetes, according to a study published online on July 1, 2019 in the European Journal of Endocrinology. The open-access article is titled “Effects of 6-Month Vitamin D Supplementation on Insulin Sensitivity and Secretion: A Randomized, Placebo-Controlled Trial.” The study findings suggest that high-dose supplementation of vitamin D can improve glucose metabolism to help prevent the development and progression of diabetes. Type 2 diabetes is an increasingly prevalent disease that places a huge burden on patients and society and can lead to serious health problems including nerve damage, blindness, and kidney failure. People at high risk of developing type 2 diabetes (prediabetics) can be identified by several risk factors, including obesity or a family history of the disease. Although low vitamin D levels have previously been associated with an increased risk of developing type 2 diabetes, some studies have reported no improvement in metabolic function. However, these studies often had a low number of participants or included individuals with normal vitamin D levels at the start who were metabolically healthy, or who had long-standing type 2 diabetes. Whether vitamin D supplementation has any beneficial effect in patients with prediabetes or with newly diagnosed diabetes, especially in those who have low vitamin D levels, has remained uncertain. In this study, Dr. Claudia Gagnon, and colleagues from Université Laval in Quebec, examined the effect of vitamin D supplementation on glucose metabolism in patients newly diagnosed with type 2 diabetes or identified as at high risk of developing the condition.