RESUMO
The main environmental risk factor associated with the development of Crohn's disease (CD) is cigarette smoking. Although the mechanism is still unknown, some studies have shown that cigarette exposure affects the intestinal barrier of the small bowel. Among the factors that may be involved in this process are Paneth cells. These specialized epithelial cells are located into the small intestine, and they are able to secrete antimicrobial peptides, having an essential role in the control of the growth of microorganisms. Alterations in its function are associated with inflammatory processes, such as CD. To study how cigarette components impact ileum homeostasis and Paneth cells integrity, we used intragastric administration of cigarette smoke condensate (CSC) in mice. Our results showed that inflammation was triggered after mucosal exposure of CSC, which induced particular alterations in Paneth cells granules, antimicrobial peptide production, and a reduction of bactericidal capacity. In fact, exposure to CSC generated an imbalance in the fecal bacterial population and increased the susceptibility of mice to develop ileal damage in response to bacterial infection. Moreover, our results obtained in mice unable to produce interleukin 10 (IL-10-/- mice) suggest that CSC treatment can induce a symptomatic enterocolitis with a pathological inflammation in genetically susceptible individuals.
Assuntos
Íleo/imunologia , Inflamação/imunologia , Mucosa Intestinal/imunologia , Produtos do Tabaco/efeitos adversos , Animais , Doença de Crohn/imunologia , Doença de Crohn/microbiologia , Íleo/microbiologia , Inflamação/microbiologia , Interleucina-10/imunologia , Mucosa Intestinal/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Celulas de Paneth/imunologia , Celulas de Paneth/microbiologiaRESUMO
Paneth cells (PCs) are specialized epithelial cells of the small bowel that contain multiple secretory granules filled with antimicrobial peptides and trophic factors, which are essential for the control of the microorganisms growth and maintaining intestinal integrity. Alterations in their function are associated with an imbalance of the normal microbiota, gastrointestinal infections and inflammatory processes, such as Crohn's disease (CD). One of the most common murine models for studying CD is IL-10-/- mouse. IL-10-/- mice when housed in conventional conditions and take contact with commensal microorganisms develop an acute enterocolitis mediated by a Th1 immune response. Even though, alterations in PCs function are related to CD, they had not been characterized yet in this mouse model. Here we show that in specific pathogen free conditions IL-10-/- mice have aberrant granules and a large number of immature PCs at the bottom of the crypt in the ileum of IL-10-/- mice before developing intestinal inflammation, along with a reduced expression of Indian Hedgehog. In addition, IL-10-/- Paneth cells presented a reduced expression of cryptidin-4, and a heterogeneous distribution of lysozyme+ granules. The alterations in the maturation of the PCs at the bottom of the crypt were not modified after the colonization by the conventional microbiota. On the other hand, depletion of microbiota altered the phenotype, but did not normalize PCs. Our results suggest that IL-10 could be necessary for the integrity of PCs. Moreover, our results help to explain why IL-10-/- mice develop enterocolitis in response to microorganisms.
Assuntos
Interleucina-10/genética , Celulas de Paneth/citologia , Vesículas Secretórias/metabolismo , alfa-Defensinas/genética , Animais , Diferenciação Celular , Células Cultivadas , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Proteínas Hedgehog/metabolismo , Masculino , Camundongos , Microbiota , Celulas de Paneth/imunologia , Celulas de Paneth/metabolismo , Fenótipo , Organismos Livres de Patógenos Específicos , Células Th1/imunologiaRESUMO
BACKGROUND: We have previously shown a reduction of gastrointestinal symptoms after the oral administration of Bifidobacterium infantis Natren Life Start super strain (NLS-SS) in untreated celiac disease (CD) patients. The symptomatic improvement was not associated with changes in intestinal permeability or serum levels of cytokines, chemokines, or growth factors. Therefore, we hypothesized that the beneficial symptomatic effect observed previously in patients with CD treated with B. infantis may be related to the modulation of innate immunity. GOALS: To investigate the potential mechanisms of a probiotic B. infantis Natren Life Start super strain on the mucosal expression of innate immune markers in adult patients with active untreated CD compared with those treated with B. infantis×6 weeks and after 1 year of gluten-free diet (GFD). METHODS: Numbers of macrophages and Paneth cells and α-defensin-5 expression were assessed by immunohistochemistry in duodenal biopsies. RESULTS: We showed that GFD decreases duodenal macrophage counts in CD patients more effectively than B. infantis. In contrast, B. infantis decreases Paneth cell counts and expression of α-defensin-5 in CD (P<0.001). CONCLUSIONS: The results identify differential innate immune effects of treatment with B. infantis compared with 1 year of GFD. Further studies are needed to investigate synergistic effects of GFD and B. infantis supplementation in CD.
Assuntos
Bifidobacterium longum subspecies infantis/crescimento & desenvolvimento , Doença Celíaca/terapia , Dieta Livre de Glúten , Duodeno/metabolismo , Imunidade Inata , Imunidade nas Mucosas , Mucosa Intestinal/metabolismo , Probióticos/uso terapêutico , alfa-Defensinas/metabolismo , Adulto , Biomarcadores/metabolismo , Biópsia , Doença Celíaca/imunologia , Doença Celíaca/metabolismo , Doença Celíaca/microbiologia , Regulação para Baixo , Duodeno/imunologia , Duodeno/microbiologia , Feminino , Microbioma Gastrointestinal , Humanos , Imuno-Histoquímica , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Masculino , Pessoa de Meia-Idade , Celulas de Paneth/imunologia , Celulas de Paneth/metabolismo , Celulas de Paneth/microbiologia , Probióticos/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
Las células de Paneth cumplen un rol muy importante en los mecanismos de defensa y protección del tracto gastrointestinal en diferentes especies animales a través de sus secreciones como lisozima, fosfolipasa y A2 secretoria y defensinas. El presente estudio tuvo por objetivo identificar las células de Paneth en el intestino delgado de crías de alpacas; para lo cual se utilizaron 18 animales entre 1 y 21 días de edad. Se tomaron muestras de duodeno, yeyuno e íleon de cada animal, las cuales fueron fijadas en formol al 10 por ciento y procesadas como muestras histológicas. Se prepararon láminas coloreadas con hematoxilina-eosina (H-E) y tricrómico de Masson. Mediante inmunohistoquímica se identificó la presencia de gránulos de lisozima para lo cual se utilizó un anticuerpo policlonal antilisozima. Mediante la coloración con H-E y tricrómico de Masson no se pudo identificar en forma precisa células típicas de Paneth, mientras que mediante inmunohistoquímica se observó células con presencia de gránulos de lisozima en la base de las criptas de Lieberkühn de duodeno, yeyuno e íleon desde 1 día de edad, siendo mayor el número en yeyuno e íleon en alpacas entre los 15 y 21 días de edad. Estas células presentaron áreas comprendidas entre 129.19 y 147.67 µm2, ejes mayores entre 17.96 y 19.92 µm y ejes menores entre 8.68 y 9.79 µm. Por lo tanto, se concluye que las células encontradas desde el primer día de edad en las criptas de Lieberkühn de duodeno, yeyuno e íleon de crías de alpacas son las células de Paneth, siendo mayor su número en yeyuno e ileon entre los 15 y 21 días de edad.
Paneth cells have an important function in the defense and protection mechanisms of gastrointestinal tract in many animal species through its secretions as lysozime, sycretory phospholipase A2 and defensins. The aim of this study was to identify the Paneth cells in the small intestine of baby alpacas; for this, 18 animals between 1 and 21 days of age were used for this purpose. Duodenum, jejunum and ileum samples were removed from each animal. By routinary microscopic light examination and immunohistochemistry, these samples were fixed in 10 per cent phormol and processed for paraffin sections and stained with haematoxylin-eosin (H-E) and Masson trichromic. For immunohistochemistry technique we used a polyclonal antibody anti-lizozime. Typicall Paneth cells were not identified with H-E and Masson trichromic stains, where as by immunohistochemistry technique Iysozime granules conteining cells were identified in the base of the crypts of Lieberkuhn of duodenum, jejunum and ileum since 1 day of age, being the number bigger in jejunum and ileum of alpacas between 15 and 21 days of age. These cells showed areas between 129.19 and 147.67 µm2, major axes between 17.96 and 19.92 µm and minor axes between 8.68 and 9.79 µm. Based in this results, it was concluded that the cells found since the first day of age in the crypts of Lieberkuhn of duodenum, jejunum and ileum of baby alpacas are Paneth cells, being the number bigger in jejunum and ileum between 15 and 21 days of age.
Assuntos
Animais , Camelídeos Americanos/anatomia & histologia , Celulas de Paneth/imunologia , Imuno-Histoquímica , Intestino Delgado/imunologiaRESUMO
Las enfermedades inflamatorias intestinales (EII), entre las que se incluyen a la enfermedad de Crohn (EC) y colitis ulcerosa (CU), son patologías de etiología multifactorial, en las cuales se ha demostrado en los últimos años que el componente genético tiene un papel relevante. La incidencia de estas patologías ha ido en aumento en los países desarrollados y también en Chile. A pesar de los avances en su estudio, la etiología de las EII no está totalmente esclarecida, aunque es posible reconocer factores genéticos, inmunológicos y ambientales en su patogénesis. Entre los posibles mecanismos propuestos la respuesta alterada a antígenos bacterianos cumpliría un papel relevante en un subgrupo de pacientes con EC quienes presentan alguna mutación en los receptores que reconocen patógenos. Esta revisión analiza avances recientes en el conocimiento de las EII y destaca los hallazgos relacionados con alteraciones en los componentes del sistema inmune gastrointestinal y su posible relación con la patogenia de las EII. Un análisis detallado de la interrelación entre los diferentes integrantes del sistema inmune de la mucosa intestinal, tales como las células dendríticas, epiteliales, de Paneth y los linfocitos T y su actividad defectuosa podría brindar nuevas herramientas para el diseño de estrategias experimentales y terapéuticas de las EII.