Cell proliferation in gastrointestinal mucosa.

Wong, Wai Man; Wright, Nicholas A.

doi:10.1136/jcp.52.5.321

Cited by 90 publications

(52 citation statements)

References 115 publications

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“…The intestinal mucosa was affected by treatments only in the jejunum, with birds fed protease B showing greater (P < 0.01) villus height and crypt depth than those treated with protease A. Although the larger crypt depth of protease-B hens suggests a higher rate of cell turnover in the villus (WONG; WRIGHT, 1999), this was probably a compensatory response associated with high levels of extrusion in the apex of the villus (CARULLI et al, 2014) and does not reflect any trophic effect of protease B on the intestinal epithelium. However, the reason for this higher rate of cell turnover was not clear.…”

Section: Discussionmentioning

confidence: 99%

Phytase and protease supplementation for laying hens in peak egg production

Vieira

Barbosa

Tavares

et al. 2016

SCA

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The effects of enzyme combinations in diets for commercial laying hens need further clarification. The goal of this study was to determine if the type of protease used in diets supplemented with phytase affects performance, nutrient intake, egg quality or intestinal mucosa morphometry of laying hens during peak egg production. Seven hundred and eighty hens (25-week-old Hy-Line W36 hens) were assigned to a completely randomized design composed of five treatments/diets with 12 replicates of 13 birds each. The five treatments were: 1) positive control: diet formulated according to the Hy-Line nutritional recommendations, without proteases , 2) negative control A: positive control diet reduced in energy, protein and amino acids according to protease A matrix, without protease supplementation, 3) negative control B: positive control diet reduced in energy, protein and amino acids according to protease B matrix, without protease supplementation, 4) negative control A plus protease A, 5) negative control B plus protease B. There was no effect of the treatments (P > 0.05) on egg production, egg mass or feed conversion; however, the nutritional restriction imposed by the negative controls reduced egg weight (negative control A, P=0.02), albumen height (P < 0.01) and the Haugh unit (P < 0.01). Protease supplementation reduced the calculated intake of protein and amino acids compared to the positive control; nevertheless, protease A was able to maintain egg weight, albumen height and the Haugh unit at the same levels as that obtained with the positive control hens. The intestinal mucosa responded to treatment only at the jejunum (P < 0.01), but the negative controls did not modify villus height or crypt depth compared to the positive control. However, crypt depth of protease B hens was higher than that of the positive control hens. In conclusion, when included in diets supplemented with phytase, the type of protease affects performance, nutrient intake, egg quality and intestinal mucosa morphometry of laying hens during peak egg production. Key words: Amino acid. Egg production. Egg quality. Enzyme. Nutritional restriction. ResumoOs efeitos da utilização em conjunto de enzimas exógenas para aves de postura precisam ser mais explorados na literatura. No intuito de determinar se o tipo de protease, em dietas suplementadas com fitase, interfere no desempenho, qualidade do ovo, ingestão de nutrientes e morfometria da mucosa intestinal de galinhas em pico de postura, 780 galinhas Hy-Line W36 de 25 semanas foram distribuídas em um delineamento inteiramente casualizado composto por cinco tratamentos/dietas com 12 repetições de 13 aves cada. Os cinco tratamentos foram: 1) controle positivo: dieta formulada de acordo com as recomendações nutricionais da Hy-Line, sem proteases, 2) controle negativo A: dieta controle positivo reduzida em energia, proteína e aminoácidos conforme a matriz nutricional da protease A, sem proteases, 3) controle negativo B: dieta controle positivo reduzida em energia, proteína e aminoácidos confor...

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Section: Discussionmentioning

confidence: 99%

Phytase and protease supplementation for laying hens in peak egg production

Vieira

Barbosa

Tavares

et al. 2016

SCA

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“…They undergo slow symmetric self-renewing cell divisions (Gage, 2000;Slack, 2000), are found in a 'niche' or distinct location (Fuchs et al, 2004;Moore and Lemischka, 2006), and generate all differentiated cell classes in a particular tissue. No other OE precursors have these characteristics, including capacity for 'label retention' that distinguishes stem cells in other epithelia (Borthwick et al, 2001;Cotsarelis et al, 1990;Wong and Wright, 1999 Marquardt and Gruss, 2002). The lateral OE, perhaps owing to antagonism between lateral RA and medial Fgf8 signaling in the context of mesenchymal/epithelial (M/E) interaction (Bhasin et al, 2003;LaMantia et al, 2000), may provide a specific niche that maintains a substantial population of Meis1-expressing precursors.…”

Section: Meis1 Oe Precursors and Oe Neural Stem Cellsmentioning

confidence: 99%

“…The distinct characteristics of embryonic OE precursors focus attention not only on molecular markers for adult counterparts, but on locations for a supportive niche, similar to those in other mature regenerating epithelia, including gut, lung and -in lower vertebrates -the retina (Borthwick et al, 2001;Hitchcock et al, 2004;Wong and Wright, 1999). If OE axes are systematically transformed between the embryo and the adult, neural stem cells should be sought along the lateral OE boundary with the respiratory epithelium.…”

Section: Defining Oe Neural Stem Cells Throughout Lifementioning

confidence: 99%

Proliferative and transcriptional identity of distinct classes of neural precursors in the mammalian olfactory epithelium

et al. 2010

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SUMMARYNeural precursors in the developing olfactory epithelium (OE) give rise to three major neuronal classes -olfactory receptor (ORNs), vomeronasal (VRNs) and gonadotropin releasing hormone (GnRH) neurons. Nevertheless, the molecular and proliferative identities of these precursors are largely unknown. We characterized two precursor classes in the olfactory epithelium (OE) shortly after it becomes a distinct tissue at midgestation in the mouse: slowly dividing self-renewing precursors that express Meis1/2 at high levels, and rapidly dividing neurogenic precursors that express high levels of Sox2 and Ascl1. Precursors expressing high levels of Meis genes primarily reside in the lateral OE, whereas precursors expressing high levels of Sox2 and Ascl1 primarily reside in the medial OE. Fgf8 maintains these expression signatures and proliferative identities. Using electroporation in the wild-type embryonic OE in vitro as well as Fgf8, Sox2 and Ascl1 mutant mice in vivo, we found that Sox2 dose and Meis1 -independent of Pbx co-factors -regulate Ascl1 expression and the transition from lateral to medial precursor state. Thus, we have identified proliferative characteristics and a dose-dependent transcriptional network that define distinct OE precursors: medial precursors that are most probably transit amplifying neurogenic progenitors for ORNs, VRNs and GnRH neurons, and lateral precursors that include multi-potent self-renewing OE neural stem cells.

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“…5 It is widely believed that the relevant target cells for the first mutation are the colonic stem cells. 6,7,[9][10][11][12][13] The argument usually goes in the following way. 14 If the first mutation happened in a proliferative daughter cell, it would be washed away before the second hit has a chance to confer a significant phenotypic change.…”

Section: Introductionmentioning

confidence: 99%