Objective: The technology for the growth of human intestinal epithelial cells is rapidly progressing. An exciting possibility is that this system could serve as a platform for individualised medicine and research. However, to achieve this goal, human epithelial culture must be enhanced so that biopsies from individuals can be used to reproducibly generate cell lines in a short time frame so that multiple, functional assays can be performed (ie, barrier function and host–microbial interactions). Design: We created a large panel of human gastrointestinal epithelial cell lines (n=65) from patient biopsies taken during routine upper and lower endoscopy procedures. Proliferative stem/progenitor cells were rapidly expanded using a high concentration of conditioned media containing the factors critical for growth (Wnt3a, R-spondin and Noggin). A combination of lower conditioned media concentration and Notch inhibition was used to differentiate these cells for additional assays. Results: We obtained epithelial lines from all accessible tissue sites within 2 weeks of culture. The intestinal cell lines were enriched for stem cell markers and rapidly grew as spheroids that required passage at 1:3–1:4 every 3 days. Under differentiation conditions, intestinal epithelial spheroids showed region-specific development of mature epithelial lineages. These cells formed functional, polarised monolayers covered by a secreted mucus layer when grown on Transwell membranes. Using two-dimensional culture, these cells also demonstrated novel adherence phenotypes with various strains of pathogenic Escherichia coli. Conclusions: This culture system will facilitate the study of interindividual, functional studies of human intestinal epithelial cells, including host–microbial interactions.
OBJECTIVE—Berberine (BBR) activates AMP-activated protein kinase (AMPK) and improves insulin sensitivity in rodent models of insulin resistance. We investigated the mechanism of activation of AMPK by BBR and explored whether derivatization of BBR could improve its in vivo efficacy. RESEARCH DESIGN AND METHODS—AMPK phosphorylation was examined in L6 myotubes and LKB1−/− cells, with or without the Ca2+/calmodulin-dependent protein kinase kinase (CAMKK) inhibitor STO-609. Oxygen consumption was measured in L6 myotubes and isolated muscle mitochondria. The effect of a BBR derivative, dihydroberberine (dhBBR), on adiposity and glucose metabolism was examined in rodents fed a high-fat diet. RESULTS—We have made the following novel observations: 1) BBR dose-dependently inhibited respiration in L6 myotubes and muscle mitochondria, through a specific effect on respiratory complex I, similar to that observed with metformin and rosiglitazone; 2) activation of AMPK by BBR did not rely on the activity of either LKB1 or CAMKKβ, consistent with major regulation at the level of the AMPK phosphatase; and 3) a novel BBR derivative, dhBBR, was identified that displayed improved in vivo efficacy in terms of counteracting increased adiposity, tissue triglyceride accumulation, and insulin resistance in high-fat–fed rodents. This effect is likely due to enhanced oral bioavailability. CONCLUSIONS—Complex I of the respiratory chain represents a major target for compounds that improve whole-body insulin sensitivity through increased AMPK activity. The identification of a novel derivative of BBR with improved in vivo efficacy highlights the potential importance of BBR as a novel therapy for the treatment of type 2 diabetes.