Live from the ASCB in Denver, CO, USA

Tuesday, December 6, 2011

New fluorescent imaging system sorts out the microbiome living in the human mouth
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Alex Valm, Marine Biological Laboratory (303KB)

The human mouth is home to a quarrelsome community of at least 600 different species of microbes—some beneficial, some potentially harmful. All pursue their own agenda while incidentally tolerating or promoting their bacterial neighbors, who in turn hurt or protect the mouth’s human owner. Sorting out this complex multispecies community is a key segment of a massive worldwide research effort to chart the human microbiome. Just identifying who’s who among the 600 species inside the mouth has not been easy, but in a proof-of-principle demonstration using human dental plaque, researchers at the Marine Biological Laboratory (MBL) in Woods Hole, MA, have demonstrated a new fluorescent labeling technology that could distinguish in a single image the population size and spatial distribution of 15 different taxa. The analysis uncovered new taxon pairings, revealing unsuspected cooperation and standoffishness between members of the microbe biofilm that covers teeth. (Read more)


Aging human bodies and aging human oocytes run on different clocks along different pathways
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Coleen T. Murphy, Princeton University (316KB)

People may scan the mirror anxiously for the first gray hair or wrinkle, but the cruelest sign of aging for half the human race is visible only on the calendar. When women pass the age of 35, their chances of infertility, miscarriage, and birth defects rise precipitously, driven by the aging and resulting quality decline of their eggs (oocytes). Reproductive cessation in women, which now occurs before the midpoint of modern life spans, stands in sharp contrast to aging in the rest of the body’s cells, called somatic cells. The question is, why? (Read more)


Could obesity be a ciliopathy, a disorder caused by tiny microtubule bundles that protrude from every cell in the hypothalamus?
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Nicolas F. Berbari, University of Alabama at Birmingham (246KB)

Obesity is a modern plague affecting populations in the developed and developing world alike. A “silver bullet” cure is unlikely because researchers still struggle with understanding how appetite is regulated. Consider the peptide leptin, for example, a fat-produced hormone that acts in a region of the brain called the hypothalamus to suppress appetite. So in theory, add leptin, stifle appetite, and then lose weight. (Read more)


A devastating “founder effect” genetic disorder identified in Quebec is traced to defective mitochondria in cerebellar neurons
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Peter S. McPherson, Neurological Institute, McGill University (292KB)

The acronym is a mouthful, but ARSACS, or autosomal recessive spastic ataxia of Charlevoix-Saguenay, is a complicated disease. ARSACS is an inherited progressive neurological disorder that first shows itself in toddlers just as they are beginning to walk. (Read more)


A hormone that dilates blood vessels during pregnancy opens an indirect pathway for treating polycystic kidney
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Heather Ward, University of New Mexico (237KB).

For something so seemingly inconsequential, primary cilia seemed an unlikely cause for something so devastating. Primary cilia are microscopic hairlike structures that stick out like antennae from virtually every cell in the human body, including the epithelial cells lining the kidneys. These nonmoving primary cilia were thought to be little more than evolutionary leftovers until 2000, when research first linked cilia defects to polycystic kidney disease (PKD), a life-threatening genetic disorder that affects 600,000 Americans, according to the National Institute of Diabetes, Digestive, and Kidney Diseases (NIDDK) and the Polycystic Kidney Disease Foundation. Half of those diagnosed with PKD will progress to end-stage renal disease by age 60. (Read more)


How viruses rewire their hosts to generate organelle platforms for replication—and why that might be their undoing
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Nihal Altan-Bonnet, Rutgers University (249KB)

For visitors who turn up with so little, viruses have a nasty way of making themselves at home in their host. A virus arrives with only its own RNA or DNA encased in a protein and/or lipid coat that protects its precious genetic material. Once inside the infected host, the virus quickly uncoats, releasing its genetic load, and starts smashing up the cellular furniture to serve its own reproductive needs. Viruses are particularly fond of assembling their replication machinery on the surface of membrane-bound cellular organelles such as the Golgi apparatus or the mitochondria. It’s like home invasion bandits setting up a crystal meth lab on your great-grandmother’s Chippendale dining table.


A cellular automation model predicts how stem cells in a population of hair follicles regenerate
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Cheng Ming Chuong, University of Southern California (306KB)

Your hair or lack of hair is the result of a lifelong tug of war between activators and inhibitors to calm or wake up stem cells in every single hair follicle on your body, according to Cheng Ming Chuong and his team at the University of Southern California (USC) plus collaborators elsewhere. They have built a predictive model of hair regeneration in rabbits, mice, and humans in which rules govern regeneration in each hair follicle individually and in all hair follicles collectively. (Read more)


Monday, December 5, 2011

Microscopic cells race to victory in first World Cell Race at ASCB meeting
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Manuel Thery 

World Cell Race pulls 70 entries for title of world’s fastest cell DENVER, CO, December 3, 2011–A “team” of fast-moving, bone marrow stem cells from a research laboratory in Singapore has run away with the first World Cell Race, finishing first with a cellular speed record of 5.2 microns per minute (or 0.000204 inches per minute) in results announced today at the 51st Annual Meeting of the American Society for Cell Biology (ASCB). (Read more)


Sunday, December 4, 2011

New host defensive weapon discovered in bacterial arms
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Pascale Cossart, Pasteur Institute and Howard Hughes Medical Institute (374KB)

In the never-ending war between pathogen and host, scientists at the Pasteur Institute in Paris have discovered a new defensive weapon, a cytoskeletal protein called septin that cages invading bacteria. The septin cages prevent the pathogens from spreading to other cells, targeting the bacteria for degradation by the cell’s internal garbage disposal system, according to Pascale Cossart and Serge Mostowy, researchers at the institution founded by Louis Pasteur, who first pioneered the study of how microbes attack humans. (Read more)


Researchers find a “druggable” chink in the molecular armor of Ras, the most commonly mutated oncogene protein in humans
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Guowei Fang, Genentech Inc. (401KB)

Ras is a notorious oncoprotein with a well-deserved reputation for being untouchable. Ras was the first identified human oncogene, a gene that when mutated could cause cancer. Ras is also the most frequently mutated oncogene, found in roughly one-quarter of all human tumors. For cancer patients, the presence of an activated Ras oncogene is a poor prognosis marker. In experiments that switch off mutated Ras in mouse cancer models, tumors typically shrink, a strong indication of potential therapeutic benefits—and yet Ras has resisted nearly all attempts to tame it in people. (Read more)



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