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The protein TAZ sends 'mixed signals' to stem cells

Just as beauty exists in the eye of the beholder, a signal depends upon the interpretation of the receiver. According to new USC research published in Stem Cell Reports, a protein called TAZ can convey very different signals -- depending upon not only which variety of stem cell, but also which part of the stem cell receives it. When it comes to varieties, some stem cells are "naïve" blank slates; others are "primed" to differentiate into certain types of more specialized cells. Among the truly naïve are mouse embryonic stem cells (ESCs), while the primed variety includes the slightly more differentiated mouse epiblast stem cells (EpiSCs) as well as so-called human "ESCs" -- which may not be true ESCs at all. In the new study, PhD student Xingliang Zhou and colleagues in the laboratory of Qi-Long Ying demonstrated that naïve mouse ESCs don't require TAZ in order to self-renew and produce more stem cells. However, they do need TAZ in order to diff...

Colon of patients with IBS reacts differently to bacteria

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Salmonella bacterium interacting with microvilli in human colon. Credit: Maria Vicario, Universitat Autonoma de Barcelona The intestinal barrier of patients with the gastrointestinal disease IBS allows bacteria to pass more freely than in healthy people, according to a study led by researchers at Linköping University in Sweden. The study, published in the scientific journal  Gastroenterology , is the first to investigate IBS using living bacteria. IBS, or irritable bowel syndrome, disturbs bowel function. The condition leads to repeated episodes of abdominal pain, and usually gives rise to constipation or diarrhea. Around 10% of people in Sweden suffer from IBS, and it is twice as common among women as among men. "People affected by IBS have been regarded as a rather diffuse group. Our study has shown that people with IBS are clearly different from healthy people in the way in which the part of the intestine known as the colon (or large intestine) reacts to bac...