Read by QxMD icon Read


Julie G In, Jennifer Foulke-Abel, Mary K Estes, Nicholas C Zachos, Olga Kovbasnjuk, Mark Donowitz
The development of indefinitely propagating human 'mini-guts' has led to a rapid advance in gastrointestinal research related to transport physiology, developmental biology, pharmacology, and pathophysiology. These mini-guts, also called enteroids or colonoids, are derived from LGR5(+) intestinal stem cells isolated from the small intestine or colon. Addition of WNT3A and other growth factors promotes stemness and results in viable, physiologically functional human intestinal or colonic cultures that develop a crypt-villus axis and can be differentiated into all intestinal epithelial cell types...
September 28, 2016: Nature Reviews. Gastroenterology & Hepatology
Thomas E Wallach, James R Bayrer
The development of sustainable intestinal organoid cell culture has emerged as a new modality for the study of intestinal function and cellular processes. Organoid culture is providing a new test-bed for therapeutic research and development. Intestinal organoids, self-renewing three-dimensional structures comprised of intestinal stem cells and their differentiated epithelial progeny allow for more facile and robust exploration of cellular activity, cell organization and structure, genetic manipulation, and vastly more physiologic modeling of intestinal response to stimuli as compared to traditional two dimensional cell line cultures...
September 14, 2016: Journal of Pediatric Gastroenterology and Nutrition
Peter J Attayek, Asad A Ahmad, Yuli Wang, Ian Williamson, Christopher E Sims, Scott T Magness, Nancy L Allbritton
The polarity of proliferative and differentiated cellular compartments of colonic crypts is believed to be specified by gradients of key mitogens and morphogens. Indirect evidence demonstrates a tight correlation between Wnt- pathway activity and the basal-luminal patterning; however, to date there has been no direct experimental manipulation demonstrating that a chemical gradient of signaling factors can produce similar patterning under controlled conditions. In the current work, colonic organoids (colonoids) derived from cultured, multicellular organoid fragments or single stem cells were exposed in culture to steep linear gradients of two Wnt-signaling ligands, Wnt-3a and R-spondin1...
2016: PloS One
Julie In, Jennifer Foulke-Abel, Nicholas C Zachos, Anne-Marie Hansen, James B Kaper, Harris D Bernstein, Marc Halushka, Sarah Blutt, Mary K Estes, Mark Donowitz, Olga Kovbasnjuk
BACKGROUND AND AIMS: Enterohemorrhagic E. coli (EHEC) causes over 70,000 episodes of foodborne diarrhea annually in the USA. The early sequence of events which precede life-threatening hemorrhagic colitis and hemolytic uremic syndrome are not fully understood due to the initial asymptomatic phase of the disease and the lack of a suitable animal model. The aim of this study was to determine the initial molecular events in the interaction between EHEC and human colonic epithelium. METHODS: Human colonoids derived from adult proximal colonic stem cells were developed into monolayers to study EHEC-epithelial interactions...
January 1, 2016: Cellular and Molecular Gastroenterology and Hepatology
Nicholas C Zachos, Olga Kovbasnjuk, Jennifer Foulke-Abel, Julie In, Sarah E Blutt, Hugo R de Jonge, Mary K Estes, Mark Donowitz
Identification of Lgr5 as the intestinal stem cell marker as well as the growth factors necessary to replicate adult intestinal stem cell division has led to the establishment of the methods to generate "indefinite" ex vivo primary intestinal epithelial cultures, termed "mini-intestines." Primary cultures developed from isolated intestinal crypts or stem cells (termed enteroids/colonoids) and from inducible pluripotent stem cells (termed intestinal organoids) are being applied to study human intestinal physiology and pathophysiology with great expectations for translational applications, including regenerative medicine...
February 19, 2016: Journal of Biological Chemistry
Maxime M Mahe, Nambirajan Sundaram, Carey L Watson, Noah F Shroyer, Michael A Helmrath
The epithelium of the gastrointestinal tract is constantly renewed as it turns over. This process is triggered by the proliferation of intestinal stem cells (ISCs) and progeny that progressively migrate and differentiate toward the tip of the villi. These processes, essential for gastrointestinal homeostasis, have been extensively studied using multiple approaches. Ex vivo technologies, especially primary cell cultures have proven to be promising for understanding intestinal epithelial functions. A long-term primary culture system for mouse intestinal crypts has been established to generate 3-dimensional epithelial organoids...
2015: Journal of Visualized Experiments: JoVE
Asad A Ahmad, Yuli Wang, Adam D Gracz, Christopher E Sims, Scott T Magness, Nancy L Allbritton
BACKGROUND: New advances enable long-term organotypic culture of colonic epithelial stem cells that develop into structures known as colonoids. Colonoids represent a primary tissue source acting as a potential starting material for development of an in vitro model of the colon. Key features of colonic crypt isolation and subsequent colonoid culture have not been systematically optimized compromising efficiency and reproducibility. Here murine crypt isolation yield and quality are optimized, and colonoid culture efficiency measured in microfabricated culture devices...
2014: Journal of Biological Engineering
Yuli Wang, Asad A Ahmad, Christopher E Sims, Scott T Magness, Nancy L Allbritton
The proliferative compartment of the colonic epithelium in vivo is located in the basal crypt where colonic stem cells and transit-amplifying cells reside and fuel the rapid renewal of non-proliferative epithelial cells as they migrate toward the gut lumen. To mimic this tissue polarity, microstructures composed of polydimethylsiloxane (PDMS) microwells and Matrigel micropockets were used to guide a combined 2-dimensional (2D) and 3-dimensional (3D) hybrid culture of primary crypts isolated from the murine colon...
May 7, 2014: Lab on a Chip
Yumiko Hirokawa, Kelvin Hon Yan Yip, Chin Wee Tan, Antony W Burgess
A stable and efficient system for the culture of murine colon epithelial cells or crypts is required to facilitate studies of the dynamics and factors affecting colon stem cell niche and crypt formation. Survival of colonic epithelial cells or crypts in vitro was not established until recently, when it was found that exogenous Wnt3A and R-spondin could promote cell survival and formation of spheroids (colonospheres) or some advanced organoids with well-developed crypts (colonoids). However, after 6-8 days in these culture conditions, only small numbers of colonospheres form organoids with crypt-like structures (colonoids)...
April 1, 2014: American Journal of Physiology. Gastrointestinal and Liver Physiology
Yuli Wang, Asad A Ahmad, Pavak K Shah, Christopher E Sims, Scott T Magness, Nancy L Allbritton
Crypts are the basic structural and functional units of colonic epithelium and can be isolated from the colon and cultured in vitro into multi-cell spheroids termed "colonoids". Both crypts and colonoids are ideal building blocks for construction of an in vitro tissue model of the colon. Here we proposed and tested a microengineered platform for capture and in vitro 3D culture of colonic crypts and colonoids. An integrated platform was fabricated from polydimethylsiloxane which contained two fluidic layers separated by an array of cylindrical microwells (150 μm diameter, 150 μm depth) with perforated bottoms (30 μm opening, 10 μm depth) termed "microstrainers"...
December 7, 2013: Lab on a Chip
P Chandrakesan, B Roy, L U M R Jakkula, I Ahmed, P Ramamoorthy, O Tawfik, R Papineni, C Houchen, S Anant, S Umar
DCLK1 and Lgr5 have recently been identified as markers of quiescent and cycling stem cells in the small intestinal crypts, respectively. Epithelial-mesenchymal transition (EMT) is a key development program that is often activated during cancer invasion and metastasis, and also imparts a self-renewal capability to disseminating cancer cells. Utilizing the Citrobacter rodentium (CR)-induced transmissible murine colonic hyperplasia (TMCH) model, we observed a relative decrease in DCLK1 expression in the colonic crypts, with significant shift towards stromal staining at peak (12 days post infection) hyperplasia, whereas staining for Lgr5 and Msi-1 increased several fold...
May 15, 2014: Oncogene
Matthias Stelzner, Michael Helmrath, James C Y Dunn, Susan J Henning, Courtney W Houchen, Calvin Kuo, John Lynch, Linheng Li, Scott T Magness, Martin G Martin, Melissa H Wong, Jian Yu
Many advances have been reported in the long-term culture of intestinal mucosal cells in recent years. A significant number of publications have described new culture media, cell formations, and growth patterns. Furthermore, it is now possible to study, e.g., the capabilities of isolated stem cells or the interactions between stem cells and mesenchyme. However, at the moment there is significant variation in the way these structures are described and named. A standardized nomenclature would benefit the ability to communicate and compare findings from different laboratories using the different culture systems...
June 15, 2012: American Journal of Physiology. Gastrointestinal and Liver Physiology
S Ramalingam, G W Daughtridge, M J Johnston, A D Gracz, S T Magness
Sox9 is an high-mobility group box transcription factor that is expressed in the stem cell zone of the small intestine and colon. We have previously used a Sox9EGFP mouse model to demonstrate that discrete levels of Sox9 expression mark small intestine epithelial stem cells that form crypt/villus-like structures in a three-dimensional culture system (Formeister EJ, Sionas AL, Lorance DK, Barkley CL, Lee GH, Magness ST. Am J Physiol Gastrointest Liver Physiol 296: G1108-G1118, 2009; Gracz AD, Ramalingam S, Magness ST...
January 1, 2012: American Journal of Physiology. Gastrointestinal and Liver Physiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"