Researchers have identified an underlying biochemical mechanism that helps make cholera toxin so deadly, often resulting in life-threating diarrhea.
Two groups of scientists at the University of California, San Diego, worked on fruit flies, mice and cultured human intestinal cells to study cholera toxin, produced by the highly infectious bacterium Vibrio cholerae.
They discovered the toxin exerts some of its devastating effects by reducing the delivery of proteins to molecular junctions that normally act like Velcro to hold intestinal cells together in the outer lining of the gut. The UC San Diego researchers found that cholera toxin acts by two entirely distinct, but cooperating mechanisms to produce diarrhea. In addition to increasing the efflux of chloride ions through a protein channel called CFTR, it weakens cell junctions to allow a rapid outflow of counterbalancing sodium ions and water between the cells.
The scientists showed that many of the effects of the cholera toxin on the gut could be reversed by genetic manipulations that bolster the delivery of proteins to these junctions.
Understanding this novel mechanism of cholera action could also have important implications for other disorders of intestinal barrier function such as Crohn’s disease, colitis and celiac disease. (ANI)
The study is published in the journal Cell Host and Microbe. (ANI)
‘Forgo sugary drinks to abate gout effects‘
Sufferers of gout might soon be advised to forgo sugary drinks to avoid pain and flaring up of the crippling affliction, according to a New Zealand study released Thursday.
Scientists at the University of Otago and the University of Auckland have discovered a human gene variant that can “turn bad” when affected by sugary drinks, Xinhua reported citing the study.
It showed that when the variant of the gene SLC2A9 behaved correctly, it helped transport uric acid out of the bloodstream and facilitated its excretion through the kidney.
“But when people with this gene variant consume sugary drinks, the apparent function of the gene variant reverses, such that we think uric acid is instead transported back into the blood stream and the risk of gout is increased,” Tony Merriman, associate professor in University of Otago’s biochemistry department, said in a statement. SLC2A9 is a newly identified urate transporter influencing serum urate concentration, urate excretion and gout.
“So not only does sugar raise uric acid in the blood due to processing in the liver, but it also appears to directly interfere with excretion of uric acid from the kidney. This was a quite unpredictable interaction,” he said. “Daily 300-millilitre serving of sugar-sweetened drink increases the chance of gout by 13 percent,” said the professor.
He recommended people with gout to avoid sugary drinks. Gout is caused when uric acid in the blood crystallises in the joints, causing them to become inflamed. It is the most common form of arthritis in New Zealand, particularly among men. The disease has strong links with other metabolic diseases such as diabetes, heart and kidney disease. (ANI)