Deficiency of haematopoietic-cell-derived IL-10 does not exacerbate high-fat-diet-induced inflammation or insulin resistance in mice.

AIMS/HYPOTHESIS: Recent work has identified the important roles of M1 pro-inflammatory and M2 anti-inflammatory macrophages in the regulation of insulin sensitivity. Specifically, increased numbers of M2 macrophages and a decrease in M1 macrophages within the adipose tissue are associated with a state of enhanced insulin sensitivity. IL-10 is an anti-inflammatory cytokine and is a critical effector molecule of M2 macrophages. METHODS: In the present study, we examined the contribution of haematopoietic-cell-derived IL-10 to the development of obesity-induced inflammation and insulin resistance. We hypothesised that haematopoietic-cell-restricted deletion of IL-10 would exacerbate obesity-induced inflammation and insulin resistance. Lethally irradiated wild-type recipient mice receiving bone marrow from either wild-type or Il10-knockout mice were placed on either a chow or a high-fat diet for a period of 12 weeks and assessed for alterations in body composition, tissue inflammation and glucose and insulin tolerance. RESULTS: Contrary to our hypothesis, neither inflammation, as measured by the activation of pro-inflammatory stress kinases and gene expression of several pro-inflammatory cytokines in the adipose tissue and liver, nor diet-induced obesity and insulin resistance were exacerbated by the deletion of haematopoietic-cell-derived IL-10. Interestingly, however, Il10 mRNA expression and IL-10 protein production in liver and/or adipose tissue were markedly elevated in Il10-knockout bone-marrow-transplanted mice relative to wild-type bone marrow-transplanted mice. CONCLUSIONS/INTERPRETATION: These data show that deletion of IL-10 from the haematopoietic system does not potentiate high-fat diet-induced inflammation or insulin resistance.

Focal neurological deficits and West Nile virus infection.

Our experience with West Nile virus infection revealed that 54% of 28 patients had a focal neurological deficit at presentation. A meningitis or encephalitis syndrome was absent in 47% of patients with focal deficits. Details of the variety of deficits, the time to development of deficits, and the associated radiological and laboratory findings are also discussed in the present report.

Clonogenic growth of epithelial cells from normal colonic mucosa from both mice and humans.

BACKGROUND & AIMS: The factors controlling the proliferation and differentiation of the colonic mucosa are unknown and have proved difficult to identify mainly because of a lack of in vitro methods for studying the proliferative cells of the mucosa. METHODS: We have developed a novel method of preparing a viable single-cell suspension from isolated crypts and cloning these single cells. RESULTS: We have obtained clonogenic growth from this single-cell suspension with an average of 1 colony per 10(5) cells in control cultures. Addition of conditioned medium from the LIM1863 colon carcinoma cell line increased the mean colony number to 11 +/- 3 per 10(5) cells. The cells forming the colonies are still viable after 4 weeks in culture. The epithelial nature of the cells was confirmed by ultrastructural and immunohistochemical methods with staining for keratin 8 and 18 and anti-human epithelial membrane-specific antigen and a positive result on polymerase chain reaction for keratin 19. CONCLUSIONS: We have successfully cloned single cells from disaggregated colonic crypts from both human and murine colonic mucosa. We have also demonstrated the presence of an active clonogenic factor in the conditioned medium of a colon carcinoma cell line. Assays show that the clonogenic activity in the conditioned medium is not caused by the presence of any of the epidermal growth factor family of growth factors. This is the first report of a clonogenic assay for epithelial cells of normal colonic mucosa.