An existing drug for glaucoma also prompted regrowth of body hair in mouse experiments, as well as human scalp hair in vitro. Also this week: bacteria against bacteria.
Is It Glaucoma, Or Just A Hair in Your Eye?
An FDA-approved glaucoma drug stimulated human hair-follicle development in cell culture and native hair regrowth in mice, suggesting potential as a treatment for baldness.
Already approved for lengthening eyelashes as well as for reducing intraocular pressure, bimatoprost (Latisse, Lumigan) had not been investigated for stimulating scalp hair. Eyelash hairs and follicles have a distinct structure and biology that remain unaffected by androgens, according to a study reported in the FASEB Journal.
In a series of experiments, investigators successfully grew human hair follicles and hair in cell culture treated with bimatoprost. They also applied bimatoprost to bald spots on mice, which subsequently had hair regrowth.
"We hope this study will lead to the development of a new therapy for balding, which should improve the quality of life for many people with hair loss," Valerie Randall, of the University of Bradford in England, said in a statement. "Further research should increase our understanding of how hair follicles work and thereby allow new therapeutic approaches for many hair growth disorders."
Gerald Weissman, MD, editor-in-chief of the FASEB Journal, suggested the vanity appeal should not be underestimated: "This discovery could be the long-awaited follow-up to Viagra that middle-aged men have been waiting for."
-- Charles Bankhead
C. difficile-Fighting Bacteria Combo Isolated
Researchers have found a combination of six gut-based bacteria that may help suppress Clostridium difficile infections.
The team isolated different combinations of gut flora after fecal transplant that "rapidly restored a diverse, healthy microbiota" and successfully suppressed the O27 strain of C. difficile, wrote Trevor Lawley, PhD, of Wellcome Trust Sanger Institute in Hinxton, England, and colleagues in PLoS Pathogens.
The strain targeted by this therapy is particularly virulent because the bacteria releases treatment-resistant spores that persist in the environment. C. difficile is a difficult-to-treat bacteria that resists vancomycin and other standard therapies, and can lead to readmission and even death.
The mouse study by Lawley and co-authors builds on recently re-established data showing fecal transplant is an effective treatment for C. difficile at IDweek 2012 in San Diego.
"Targeting a dysbiotic microbiota with a defined mixture of phylogenetically diverse bacteria can trigger major shifts in the microbial community structure" that inhibits C. difficile, and, "as a result, resolves disease and contagiousness," the authors added.
-- Cole Petrochko
Powerful Antibiotics Allow Bacteria to Make Some Protein
Not all macrolide antibiotics kill bacteria by completely shutting down protein synthesis in the pathogens, as was previously believed.
Inhibiting production of proteins by the ribosomes is the mechanism explaining the drugs' effects, but Alexander Mankin, PhD, of the University of Illinois at Chicago, and colleagues found that complete production shutdown is not necessary.
As they reported in Cell, two older macrolides -- erythromycin and azithromycin – impaired protein production to a greater extent than the more powerful, newer-generation ketolides, which are derived from erythromycin. All of the drugs act by plugging the so-called polypeptide exit tunnel of the ribosome.
"We now believe that allowing cells to make some proteins could be much more damaging for a microbe than not letting it make any proteins at all," Mankin said in a statement. The finding could be used to create improved antibiotics and treatments for other diseases.
"If a chemical can be designed that binds to the human ribosome and allows it to make good proteins but not bad ones, such as mutant enzymes or proteins that promote cancer, then such new drugs can treat many human maladies," he said.
-- Todd Neale
Serendipity and a Lupus Autoantibody
While trying to turn autoantibodies characteristic of systemic lupus erythematosus (SLE) into vehicles for therapeutic molecules, researchers found that one specific autoantibody itself was lethal to cancer cells.
Led by Peter M. Glazer, MD, PhD, of Yale University, the researchers showed that the autoantibodies inhibited DNA repair – a finding that is of particular importance for cancers associated with BRCA mutations, which are characterized by faulty repair of single- and double-stranded DNA. They found that, when ovarian cancer cells were exposed to the autoantibody 3E10, doxorubicin alone, or 3E10 and low-dose doxorubicin, the antibody-exposed cells were more highly sensitized to the chemotherapeutic agent and were selectively killed.
These findings suggest that 3E10 could provide a novel approach to enhancing targeted therapy for breast, ovarian, and prostate cancers – malignancies that happen to be less common in patients with lupus than in the wider population.
"It is now tempting to speculate that circulating lupus autoantibodies in [SLE] patients provides protection against the development of BRCA2-mutated tumors," Glazer and colleagues wrote in Science Translational Medicine.
-- Nancy Walsh
Longer Obesity Lessens Weight Loss
The longer obesity lingers, the harder it is to shed pounds, researchers found in a mouse model.
Malcolm Low, MD, PhD, of the University of Michigan, and colleagues turned off hypothalamic expression of a gene -- proopiomelanocortin (POMC) -- that puts the brakes on hunger in mice.
They then reactivated its expression at various stages of overweight, which reduced food intake and alleviated hyperglycemia and fatty liver.
But the effectiveness of this treatment tapered off as the level of obesity and the time of POMC re-expression increased, they reported in the Journal of Clinical Investigation.
The findings "reveal the critical importance of early intervention for the prevention of subsequent allostatic overload that auto-perpetuates obesity," they wrote.
-- Kristina Fiore