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How the Slime Mold Gets Organized

By Guest PostMarch 13, 2011Sciencealpha catenin, animals cells, asymmetric epithelial cells, beta catenin, cells, cellular slime mold, daniel dickinson, embryo forms, epithelial cells, epithelium, fruiting body, high powered microscope, hollow structure, james nelson, man behind the curtain, multicellular organism, proteins, slime mold, stress, unicellular organism, william weis

*Cells at the tip of the slime mold’s fruiting body organize into an epithelial layer and secrete proteins as do some animals cells*

The so-called cellular slime mold, a unicellular organism that may transition into a multicellular organism under stress, has just been found to have a tissue structure that was previously thought to exist only in more sophisticated animals. What’s more, two proteins that are needed by the slime mold to form this structure are similar to those that perform the same function in more sophistical animals.

Shortly after an animal embryo forms, it develops a single layer of cells that, shaped like a hollow ball, is empty at its center. Acting as a kind of “man behind the curtain” that directs these cells to organize into this hollow formation are several proteins that help each cell touch its neighbors but keep its top surface exposed to the formation’s empty interior. (more…)

Replacing Body Parts Now More Than ‘Science Fiction’

By Guest PostFebruary 19, 2011Sciencecells, clinical trials, clotting, engineered lungs, genetically different cells, human body, human veins, infection, laura niklason, lunatic fringe, natural lungs, obstruction, regenerative medicine, science fiction, time of my life, tissue engineered lungs, tissue engineered replacement, vascular surgeons, vascular system

If Dr. Laura Niklason has her way, vascular surgeons will someday be able to pull human veins off a shelf, whenever they want, to save lives.

Niklason is a pioneer in the science — and art — of tissue-engineered replacement of human body components. Last year, she led a research team that successfully implanted tissue-engineered lungs, cultured in vitro, in adult rats. For short intervals of time, the engineered lungs exchanged oxygen and carbon dioxide similarly to natural lungs. (more…)

How Pathogens Hijack Host Plants

By Guest PostNovember 27, 20101 commentSciencearabidopsis, bacteria, cell membrane, cells, diabetes, fluorescence resonance energy transfer, frank white, fret, fungi, global crop, infestation, li-qing chen, mustard, mutation, novel transporters, organism, pathogen infection, pathogenic bacteria, pathogens, plant nutrients, pore proteins, protein genes, sensor-based technology, sugar efflux, sugar-pumping mechanism, sweets

Palo Alto, CA — Infestation by bacteria and other pathogens result in global crop losses of over $500 billion annually. A research team led by the Carnegie Institution’s Department of Plant Biology developed a novel trick for identifying how pathogens hijack plant nutrients to take over the organism. They discovered a novel family of pores that transport sugar out of the plant. Bacteria and fungi hijack the pores to access the plant sugar for food. The first goal of any pathogen is to access the host’s food supply to allow them to reproduce in large numbers. This is the first time scientists have a direct handle on controlling the food supply to pathogens and thus a new means to prevent a wide range of crop diseases and losses. (more…)

UCLA Researchers Identify Molecular Program for Brain Repair Following Stroke

By Guest PostNovember 13, 20101 commentHealth, Scienceadult brain, atrx, axons, brain, brain stroke, carmichael, cells, DNA, drug, gene, giovanni coppola, healing process, molecular cascade, mouse, neurons, peri infarct tissue, s thomas carmichael, stroke

Mouse Stroke. An MRI of a mouse brain after stroke. The mouse section has been stained to show cell bodies. Image credit: University of California

A stroke wreaks havoc in the brain, destroying its cells and the connections between them. Depending on its severity and location, a stroke can impact someone’s life forever, affecting motor activity, speech, memories, and more.

The brain makes an attempt to rally by itself, sprouting a few new connections, called axons, that reconnect some areas of the brain. But the process is weak, and the older the brain, the poorer the repair. Still, understanding the cascade of molecular events that drive even this weak attempt could lead to developing drugs to boost and accelerate this healing process.

Now researchers at UCLA have achieved a promising first step. Reporting in the current online edition of the journal Nature Neuroscience, senior author Dr. S. Thomas Carmichael, a UCLA associate professor of neurology, and colleagues have, for the first time, identified in the mouse the molecular cascade that drives the process of reconnection or sprouting in the adult brain after stroke. (more…)

New 3-D Model of RNA ‘Core Domain’ of Enzyme Telomerase May Offer Clues to Cancer, Aging

By Guest PostNovember 6, 2010Health, Scienceaging, cancer, cells, chromosomes, DNA, dna damage, enzyme, helical extension, juli feigon, medicine, nmr, nobel prize, nuclear magnetic resonance, physiology, proteins, pseudoknot, qi zhang, rna, spectroscopy, telomerase, telomeres, virus

A model representation of telomerase's RNA "core domain," determined by Juli Feigon, Qi Zhang and colleagues in Feigon's UCLA laboratory. Image credit: Juli Feigon, UCLA Chemistry and Biochemistry/PNAS

Telomerase is an enzyme that maintains the DNA at the ends of our chromosomes, known as telomeres. In the absence of telomerase activity, every time our cells divide, our telomeres get shorter. This is part of the natural aging process, as most cells in the human body do not have much active telomerase. Eventually, these DNA-containing telomeres, which act as protective caps at the ends of chromosomes, become so short that the cells die.

But in some cells, such as cancer cells, telomerase, which is composed of RNA and proteins, is highly active and adds telomere DNA, preventing telomere shortening and extending the life of the cell.

UCLA biochemists have now produced a three-dimensional structural model of the RNA “core domain” of the telomerase enzyme. Because telomerase plays a surprisingly important role in cancer and aging, understanding its structure could lead to new approaches for treating disease, the researchers say. (more…)

U of T researcher discovers key protein involved in DNA repair

By Guest PostAugust 22, 2010Health, Scienceanne‐claude gingras, cancer, cancer development, cells, daniel durocher, dann, dna repair, frank sicheri, genetic material, mount sinai hospital, mutations, otub1, protein, riddle syndrome, rna interference, rnai, samuel lunenfeld research institute, thomas kierans research chair

*Discovery gives insight into the way cells protect their own genetic material*

In a groundbreaking study, U of T researchers including Professors Daniel Durocher, Anne‐Claude Gingras and Frank Sicheri have uncovered a protein called OTUB1 that blocks DNA damage in the cell—a discovery that may lead to the development of strategies to improve some cancer therapies.

(more…)

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