MicroRNA mediates gene-diet interaction related to obesity

Eating more n-3 polyunsaturated fatty acids, commonly known as omega-3 fatty acids, may help carriers of a genetic variant on the perilipin 4 (PLIN4) gene locus lose weight more efficiently.

Led by Jose M. Ordovas, PhD, director of the Nutrition and Genomics Laboratory at the USDA HNRCA, researchers genotyped seven single nucleotide polymorphisms (SNPs), also known as gene variants, from men and women of mostly white European ancestry enrolled in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study and the Framingham Offspring Study. Carriers of the gene variant tended to weigh more and exhibit higher body mass index (BMI), which would increase their risk of becoming obese. Yet carriers with higher omega-3 fatty acid intakes tended to weigh less than carriers who consumed little or no omega-3 fatty acids.

Researchers make first direct observation of 3-D molecule folding in real time

All the crucial proteins in our bodies must fold into complex shapes to do their jobs. These snarled molecules grip other molecules to move them around, to speed up important chemical reactions or to grab onto our genes, turning them “on” and “off” to affect which proteins our cells make.

Programming Biomolecular Self-Assembly Pathways

Nature knows how to make proteins and nucleic acids (DNA and RNA) dance to assemble and sustain life. Inspired by this proof of principle, researchers at the California Institute of Technology have demonstrated that it is possible to program the pathways by which DNA strands self-assemble and disassemble, and hence to control the dynamic function of the molecules as they traverse these pathways.

Bioengineers Devise ‘Dimmer Swith’ To Regulate Gene Expression In Mammal Cells

Three Boston University biomedical engineers have created a genetic dimmer switch that can be used to turn on, shut off, or partially activate a gene’s function. Professor James Collins, Professor Charles Cantor and doctoral candidate Tara Deans invented the switch, which can be tuned to produce large or small quantities of protein, or none at all

This switch helps advance the field of synthetic biology, which rests on the premise that complex biological systems can be built by arranging components or standard parts, as an electrician would to build an electric light switch. Much work in the field to date uses bacteria or yeast, but the Boston University team used more complex mammalian cells, from hamsters and mice. The switch has several new design features that extend possible applications into areas from basic research to gene therapy.

Mechanism of microRNAs deciphered

Over 30% of our genes are under the control of small molecules called microRNAs. They prevent specific genes from being turned into protein and regulate many crucial processes like cell division and development, but how they do so has remained unclear. Now researchers from the European Molecular Biology Laboratory (EMBL) have developed a new method that uncovered the mode of action of microRNAs in a test tube. The study, which is published in the current online issue of Nature, reveals that microRNAs block the initiation of translation, the earliest step in the process that turns genetic information stored on messenger RNAs into proteins.

Scientists identify critical gene factor in heart development

Researchers at the Gladstone Institute of Cardiovascular Disease (GICD) announced they have identified a critical genetic factor in the control of many aspects of heart form and function. As reported in the journal Cell, scientists in the lab of Deepak Srivastava, MD, have successfully deleted a genetic factor, called a microRNA, in animal models to understand the role it plays in cardiovascular differentiation and development.

Scientists discover new class of RNA

The last few years have been very good to ribonucleic acid (RNA). Decades after DNA took biology by storm, RNA was considered little more than a link in a chain–no doubt a necessary link, but one that, by itself, had little to offer. But with the discoveries of RNA interference and microRNAs, this meager molecule has been catapulted to stardom as a major player in genomic activity.

Now, a team of scientists led by David Bartel, a professor in MIT’s Department of Biology, has discovered an entirely new class of RNA molecules.

Regulating the nuclear architecture of the cell

An organelle called the nucleolus resides deep within the cell nucleus and performs one of the cell’s most critical functions: it manufactures ribosomes, the molecular machines that convert the genetic information carried by messenger RNA into proteins that do the work of life.

Gary Karpen and Jamy Peng, researchers in the Life Sciences Division of the Department of Energy’s Lawrence Berkeley National Laboratory, have now discovered two pathways that regulate the organization of the nucleolus and other features of nuclear architecture, maintaining genome stability in the fruit fly Drosophila melanogaster.

Technique reveals inner lives of red blood cells

For the first time, researchers at MIT can see every vibration of a cell membrane, using a technique that could one day allow scientists to create three-dimensional images of the inner workings of living cells.

Studying cell membrane dynamics can help scientists gain insight into diseases such as sickle cell anemia, malaria and cancer. Using a technique known as quantitative phase imaging, researchers at MIT’s George R. Harrison Spectroscopy Laboratory can see cell membrane vibrations as tiny as a few tens of nanometers (billionths of a meter).

Tiny RNA molecules fine-tune the brain’s synapses

Non-coding regions of the genome – those that don’t code for proteins – are now known to include important elements that regulate gene activity. Among those elements are microRNAs, tiny, recently discovered RNA molecules that suppress gene expression. Increasing evidence indicates a role for microRNAs in the developing nervous system, and researchers from Children’s Hospital Boston now demonstrate that one microRNA affects the development of synapses – the points of communication between brain cells that underlie learning and memory.

A method is developed to silence genes in specific tissues using RNAi

Researchers at The University of Texas M. D. Anderson Cancer Center say they have jumped a significant hurdle in the use of RNA interference (RNAi), believed by many to be the ultimate tool to both decode the function of individual genes in the human genome and to treat disease.

Reporting in the journal Genes and Development, investigators have developed a simple way to use the RNAi approach to silence a selected gene in a specific tissue in a mouse to determine the function of that targeted gene.

This is another major breakthrough related to RNA interferene that was the topic of my prior post.

Long-term memory controlled by molecular pathway at synapses

Harvard University biologists have identified a molecular pathway active in neurons that interacts with RNA to regulate the formation of long-term memory in fruit flies. The same pathway is also found at mammalian synapses, and could eventually present a target for new therapeutics to treat human memory loss.

Scientists Discover a Gene That Regulates Lifespan

Genes that control the timing of organ formation during development also control timing of aging and death, and provide evidence of a biological timing mechanism for aging, Yale researchers report in the journal Science.

“Although there is a large variation in lifespan from species to species, there are genetic aspects to the processes of development and aging,” said Frank Slack, associate professor of Molecular, Cellular and Developmental Biology and senior author of the paper. “We used the simple, but genetically well-studied, C. elegans worm and found genes that are directly involved in determination of lifespan. Humans have genes that are nearly identical.”

Researchers hone in on differentiation of heart stem cells

A team of scientists from the Gladstone Institute of Cardiovascular Disease (GICD) has identified a key factor in heart development that could help advance gene therapy for treating cardiac disorders.

The findings could help cardiac stem cell researchers one day develop strategies for gene and cell- mediated cardiac therapies.

New Study Expands Understanding Of The Role Of RNA Editing In Gene Control

For many years, scientists thought gene activity was relatively straightforward: Genes were transcribed into messenger RNA, which was processed and translated into the proteins of the body. Certainly, there were many factors governing the transcription process, but gene control happened at the level of the DNA

In the past few years, however, evidence for a more nuanced understanding of the total genetic system has steadily accumulated. Researchers at The Wistar Institute and elsewhere have been teasing out the details of a process called RNA editing, in which messenger RNA sequence is altered after transcription by editing enzymes, so that a single gene can produce a number of related but distinct variant proteins. Most recently, scientists have discovered an extensive family of small molecules called microRNAs, or miRNAs, that appear to target and inactivate particular messenger RNAs. This targeted gene silencing is now seen as one of the body’s primary strategies for regulating its genome.