Human parthenogenetic embryo stem cells: appreciating what you have when you have it

In this issue of Cell Stem Cell, Kim et al. (2007b) show, by genome-wide single-nucleotide polymorphism analysis, that human ES cells claimed to originate from a somatic cell nuclear transfer (SCNT) embryo are actually parthenogenetic. This now permits an appreciation of the future therapeutic utility of this type of cell.     

Epithelial lineages of the small intestine have unique patterns of GATA expression

The ability of the GATA family of factors to interact with numerous other factors, co-factors, and repressors suggests that they may play key roles in tissues and cells where they are expressed. Adult mouse small intestine has been shown to express GATA-4, GATA-5, and GATA-6, where they have been implicated in the activation of a number of intestinal genes. Determination of which GATA factor(s) are involved in a specific function in tissues expressing multiple family members has proven difficult. The immunohistochemical analysis presented here demonstrate that within the mouse small intestine GATA-4/-5/-6 are found to be uniquely distributed among the various differentiated lineages of the intestinal epithelium. Among differentiated cells GATA-4 is found only in the villous enterocytes. GATA-5 is absent from enterocytes, but was found in the remaining lineages: goblet, Paneth and enteroendocrine. Additionally, high levels of GATA-6 are found in only one of these differentiated cell types, the enteroendocrine lineage. The observed distribution suggests that the GATA factors may have distinct roles in lineage allocation, lineage maintenance, and/or terminal differentiation events in small intestine.     

Luminal leptin activates mucin-secreting goblet cells in the large bowel

Leptin has been suggested to be involved in tissue injury and/or mucosal defence mechanisms. Here, we studied the effects of leptin on colonic mucus secretion and rat mucin 2 (rMuc2) expression. Wistar rats and ob/ob mice were used. Secretion of mucus was followed in vivo in the rat perfused colon model. Mucus secretion was quantified by ELISA, and rMuc2 mRNA levels were quantified by real-time RT PCR. The effects of leptin alone or in association with protein kinase C (PKC) and phosphatidylinositol 3-kinase (PI3K) inhibitors on mucin secreted by human mucus-secreting HT29-MTX cells were determined. Leptin was detected in the rat colonic lumen at substantial levels. Luminal perfusion of leptin stimulates mucus-secreting goblet cells in a dose-dependent manner in vivo in the rat. Leptin (10 nmol/l) increased mucus secretion by a factor of 3.5 and doubled rMuc2 mRNA levels in the colonic mucosa. There was no damage to mucosa 24 h after leptin, but the number of stained mucus cells significantly increased. Leptin-deficient ob/ob mice have abnormally dense mucus-filled goblet cells. In human colonic goblet-like HT29-MTX cells expressing leptin receptors, leptin increased mucin secretion by activating PKC- and PI3K-dependent pathways. This is the first demonstration that leptin, acting from the luminal side, controls the function of mucus-secreting goblet cells. Because the gel layer formed by mucus at the surface of the intestinal epithelium has a barrier function, our data may be relevant physiologically in defence mechanisms of the gastrointestinal tract.     

Yin and yang: Cancer-implicated miRNAs that have it both ways

Comment on: Huse JT, et al. Genes Dev 2009; 23:1327-37. AND Kota J, et al. Cell 2009; 137:1005-17.     

The eyes don't have it: lie detection and Neuro-Linguistic Programming

Proponents of Neuro-Linguistic Programming (NLP) claim that certain eye-movements are reliable indicators of lying. According to this notion, a person looking up to their right suggests a lie whereas looking up to their left is indicative of truth telling. Despite widespread belief in this claim, no previous research has examined its validity. In Study 1 the eye movements of participants who were lying or telling the truth were coded, but did not match the NLP patterning. In Study 2 one group of participants were told about the NLP eye-movement hypothesis whilst a second control group were not. Both groups then undertook a lie detection test. No significant differences emerged between the two groups. Study 3 involved coding the eye movements of both liars and truth tellers taking part in high profile press conferences. Once again, no significant differences were discovered. Taken together the results of the three studies fail to support the claims of NLP. The theoretical and practical implications of these findings are discussed.