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1.
BMC Mol Cell Biol ; 21(1): 14, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32183701

RESUMO

BACKGROUND: Fibronectin (FN) assembly into an insoluble fibrillar matrix is a crucial step in many cell responses to extracellular matrix (ECM) properties, especially with regards to the integrin-related mechanosensitive signaling pathway. We have previously reported that the silencing of expression of integrin-linked kinase (ILK) in human intestinal epithelial crypt (HIEC) cells causes significant reductions in proliferation and spreading through concomitantly acquired impairment of soluble FN deposition. These defects in ILK-depleted cells are rescued by growth on exogenous FN. In the present study we investigated the contribution of ILK in the fibrillogenesis of FN and its relation to integrin-actin axis signaling and organization. RESULTS: We show that de novo fibrillogenesis of endogenous soluble FN is ILK-dependent. This function seemingly induces the assembly of an ECM that supports increased cytoskeletal tension and the development of a fully spread contractile cell phenotype. We observed that HIEC cell adhesion to exogenous FN or collagen-I (Col-I) is sufficient to restore fibrillogenesis of endogenous FN in ILK-depleted cells. We also found that optimal engagement of the Ras homolog gene family member A (RhoA) GTPase/Rho-associated kinase (ROCK-1, ROCK-2)/myosin light chain (MLC) pathway, actin ventral stress fiber formation, and integrin adhesion complex (IAC) maturation rely primarily upon the cell's capacity to execute FN fibrillogenesis, independent of any significant ILK input. Lastly, we confirm the integrin α5ß1 as the main integrin responsible for FN assembly, although in ILK-depleted cells αV-class integrins expression is needed to allow the rescue of FN fibrillogenesis on exogenous substrate. CONCLUSION: Our study demonstrates that ILK specifically induces the initiation of FN fibrillogenesis during cell spreading, which promotes RhoA/ROCK-dependent cell contractility and maturation of the integrin-actin axis structures. However, the fibrillogenesis process and its downstream effect on RhoA signaling, cell contractility and spreading are ILK-independent in human intestinal epithelial crypt cells.

3.
J Pediatr Gastroenterol Nutr ; 68(5): 623-629, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31022092

RESUMO

BACKGROUND AND OBJECTIVE: The use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a broad spectrum of life-threatening adverse effects on the immature gastrointestinal tract. NSAID derivatives exploiting the beneficial effects of biologically active gases, such as hydrogen sulfide (H2S), have been developed. Herein, we determined the effects of ketoprofen and ATB-352, a H2S-releasing ketoprofen derivative, on selected metabolic pathways previously identified to be significantly altered by indomethacin in the human immature intestine. METHODS: Ketoprofen and ATB-352 were tested on human mid-gestation small intestinal explants maintained in a serum-free organ culture system for 48 hours. The expression levels of the representative genes involved in selected metabolic pathways were measured by real-time PCR after a treatment of 48 hours. RESULTS: Tested at a concentration that allows more than 80% inhibition of PGE2 production, ketoprofen was found to be less damaging than indomethacin at an equivalent dosage. However, based on the inducibility of cyclooxygenase-2 transcript expression, we were able to discriminate between responder individuals in which the deleterious effects observed with indomethacin were attenuated, and non-responder specimens in which the effects were similar to those observed with indomethacin. ATB-352 did not induce significant changes compared to ketoprofen on these metabolic pathways. CONCLUSIONS: These results show less damaging effects of ketoprofen compared to indomethacin on the immature intestine and indicate that the intestinal response to this NSAID significantly varies between individuals. However, the results did not allow us to demonstrate a specific beneficial effect of H2S release in organ culture.

4.
Nat Commun ; 10(1): 1827, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015444

RESUMO

The Tip60/p400 chromatin-modifying complex, which is involved in the incorporation and post-translational modification of the H2A.Z histone variant, regulates cell proliferation and important signaling pathways, such as Wnt. Here, we study the involvement of H2A.Z in intestinal epithelial homeostasis, which is dependent on the finely-tuned equilibrium between stem cells renewal and differentiation, under the control of such pathway. We use cell models and inducible knock-out mice to study the impact of H2A.Z depletion on intestinal homeostasis. We show that H2A.Z is essential for the proliferation of human cancer and normal intestinal crypt cells and negatively controls the expression of a subset of differentiation markers, in cultured cells and mice. H2A.Z impairs the recruitment of the intestine-specific transcription factor CDX2 to chromatin, is itself a target of the Wnt pathway and thus, acts as an integrator for Wnt signaling in the control of intestinal epithelial cell fate and homeostasis.


Assuntos
Histonas/metabolismo , Homeostase/genética , Mucosa Intestinal/fisiologia , Via de Sinalização Wnt/genética , Animais , Fator de Transcrição CDX2/genética , Fator de Transcrição CDX2/metabolismo , Células CACO-2 , Diferenciação Celular/genética , Proliferação de Células/genética , Cromatina/genética , Células Epiteliais/fisiologia , Regulação da Expressão Gênica/fisiologia , Células HCT116 , Histonas/genética , Humanos , Mucosa Intestinal/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo
5.
Tissue Cell ; 56: 71-78, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30736907

RESUMO

The interactions between cells and the extracellular matrix (ECM) play a major role in normal and pathological conditions. The ECM can modulate several biological functions including cell proliferation, adhesion, differentiation and survival through its interactions with cell receptors. Laminins are one of the most important glycoproteins present in basement membranes, a type of ECM. The pattern of expression of its different isoforms depends on the spatiotemporal organization of each tissue. While integrins are the most studied laminin receptors, other non-integrin laminin receptors are also involved. This review focuses on two particular non-integrin laminin receptors in the epithelial context: dystroglycan and 37/67 laminin receptor (37/67LR). Dystroglycan is a two-subunit protein discovered in the muscle as part of the dystrophin-associated glycoprotein complex. This protein can also be found in many epithelia where its roles are variable. The 37/67LR is a still incompletely understood laminin receptor that is important to regulate intestinal epithelial cell function and could be involved in various pathological conditions.


Assuntos
Proliferação de Células/genética , Distroglicanas/genética , Laminina/genética , Receptores de Laminina/genética , Membrana Basal/metabolismo , Diferenciação Celular/genética , Células Epiteliais/metabolismo , Epitélio/metabolismo , Matriz Extracelular/genética , Humanos , Integrinas/genética
6.
Artigo em Inglês | MEDLINE | ID: mdl-30789861

RESUMO

BACKGROUND AND OBJECTIVE: The use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a broad spectrum of life-threatening adverse effects on the immature gastrointestinal tract. NSAID derivatives exploiting the beneficial effects of biologically active gases, such as hydrogen sulfide (H2S), have been developed. Herein, we determined the effects of ketoprofen and ATB-352, a H2S-releasing ketoprofen derivative, on selected metabolic pathways previously identified to be significantly altered by indomethacin in the human immature intestine. METHODS: Ketoprofen and ATB-352 were tested on human mid-gestation small intestinal explants maintained in a serum-free organ culture system for 48 h. The expression levels of the representative genes involved in selected metabolic pathways were measured by real-time PCR after a treatment of 48 hours. RESULTS: Tested at a concentration that allows more than 80% inhibition of PGE2 production, ketoprofen was found to be less damaging than indomethacin at an equivalent dosage. However, based on the inducibility of cyclooxygenase-2 transcript expression, we were able to discriminate between responder individuals in which the deleterious effects observed with indomethacin were attenuated, and non-responder specimens in which the effects were similar to those observed with indomethacin. ATB-352 did not induce significant changes compared to ketoprofen on these metabolic pathways. CONCLUSIONS: These results show less damaging effects of ketoprofen compared to indomethacin on the immature intestine and indicate that the intestinal response to this NSAID significantly varies between individuals. However the results did not allow us to demonstrate a specific beneficial effect of H2S release in organ culture.

7.
Pediatr Res ; 84(6): 813-820, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30341414

RESUMO

BACKGROUND: The use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin (INDO) and ibuprofen (IBU) has been shown to be an effective therapy for the closure of patent ductus arteriosus (PDA). However, this treatment has been associated with an increased risk of developing enteropathies in neonates. Whether the use of IBU is safer than INDO for the immature intestine remains to be elucidated. METHODS: The direct impact of IBU on the human immature intestinal transcriptome was investigated using serum-free organ culture. Differentially expressed genes were analyzed with Ingenuity Pathway Analysis software and compared with those previously reported with INDO. Validation of differentially expressed genes was confirmed by qPCR. RESULTS: We identified several biological processes that were significantly modulated by IBU at similar levels to what had previously been observed with INDO, while the expression of genes involved in "antimicrobial response" and "mucus production" was significantly decreased exclusively by IBU in the immature intestine. CONCLUSIONS: Our findings indicate that IBU has a harmful influence on the immature intestine. In addition to exerting many of the INDO observed deleterious effects, IBU alters pathways regulating microbial colonization and intestinal epithelial defense.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Ibuprofeno/efeitos adversos , Mucosa Intestinal/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Intestinos/embriologia , Anti-Inflamatórios não Esteroides/farmacologia , Meios de Cultura Livres de Soro , Dinoprostona/metabolismo , Relação Dose-Resposta a Droga , Permeabilidade do Canal Arterial/tratamento farmacológico , Feto , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Glicólise , Humanos , Ibuprofeno/farmacologia , Mucosa Intestinal/crescimento & desenvolvimento , Intestino Delgado/embriologia , Metabolismo dos Lipídeos , Análise de Sequência com Séries de Oligonucleotídeos , Técnicas de Cultura de Órgãos , Oxirredutases/metabolismo , Risco , Transcriptoma
8.
J Nutr Biochem ; 57: 56-66, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29674247

RESUMO

Inflammatory bowel diseases (IBDs) are multifaceted and relapsing immune disorders, which necessitate long-term dependence on powerful drugs. As the use of natural product-based therapies has emerged as a promising intervention, the present study aimed to further characterize dried apple peel powder (DAPP) mechanisms of action and evaluate the preventive and curative effects of DAPP on mitochondrial functions in a murine model. Induction of intestinal inflammation in mice is performed by oral administration of the dextran sodium sulfate (DSS) at 2.5% for 10 days. Doses of DAPP (200 or 400 mg/kg/day) were administered by gavage for 10 days pre- and 1 day after colitis induction simultaneously with DSS treatment for a period of 10 days. The preventive (200 mg/kg/day) and therapeutic (400 mg/kg/day) doses of DAPP limited DSS-induced histological lesions, improved macroscopic parameters and attenuated clinical signs. DAPP at the same conditions reduced massive infiltration of inflammatory cells and concomitantly displayed a robust potential of counteracting inflammation and oxidative stress in DSS mice. Moreover, DAPP partially restored mitochondrial abnormalities related to size, density, redox homeostasis, fatty acid ß-oxidation, ATP synthesis, apoptosis and regulatory mitochondrial transcription factors. Our findings demonstrate the preventive and therapeutic impact of DAPP on experimental colitis while underlying the role of mitochondria. They also suggest that this natural DAPP product may represent an interesting candidate for further studies on the prevention/treatment of IBD.


Assuntos
Colite Ulcerativa/prevenção & controle , Malus/química , Mitocôndrias/efeitos dos fármacos , Polifenóis/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Biomarcadores/metabolismo , Morte Celular/efeitos dos fármacos , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/dietoterapia , Sulfato de Dextrana/toxicidade , Ácidos Graxos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Mitocôndrias/patologia , Estresse Oxidativo/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Methods Mol Biol ; 1765: 217-227, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29589311

RESUMO

Noninvasive screening methods for the detection of colorectal cancers (CRC) at curable stages rely on the identification of specific biomarkers. Our group has shown that mRNA stool assays represent a powerful and robust approach for the prediction of colorectal neoplasms. In this methodological chapter, we describe the procedures to isolate good quality stool RNA and the steps to evaluate the levels of specific host mRNA markers such as ITGA6, MYC, and GADD45B using TaqMan-based quantitative and droplet digital PCR approaches.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer/métodos , Fezes/química , RNA Mensageiro/análise , Antígenos de Diferenciação/genética , Detecção Precoce de Câncer/instrumentação , Humanos , Integrina alfa6/genética , Proteínas Proto-Oncogênicas c-myc/genética , Reação em Cadeia da Polimerase em Tempo Real/instrumentação , Reação em Cadeia da Polimerase em Tempo Real/métodos
10.
Methods Mol Biol ; 1765: 43-56, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29589300

RESUMO

Proximal promoters are located upstream of the transcription start sites of genes, and they contain regulatory sequences on which bind different transcription factors for promoting colorectal cancer progression. Here we describe the comprehensive methodology used previously for the identification and functional characterization of MYC-responsive elements in the integrin α1 subunit (ITGA1) gene using a combination of in silico analysis, site-directed mutagenesis, and chromatin immunoprecipitation.


Assuntos
Imunoprecipitação da Cromatina/métodos , Neoplasias Colorretais/genética , Integrina alfa1/genética , Mutagênese Sítio-Dirigida/métodos , Elementos de Resposta/genética , Sítios de Ligação , Carcinogênese/genética , Imunoprecipitação da Cromatina/instrumentação , Simulação por Computador , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Mutagênese Sítio-Dirigida/instrumentação , Proteínas Proto-Oncogênicas c-myc/metabolismo , Análise de Sequência de DNA/métodos , Sítio de Iniciação de Transcrição
11.
Cancers (Basel) ; 10(2)2018 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-29401653

RESUMO

The α6 integrin subunit (ITGA6) pre-mRNA undergoes alternative splicing to form two splicing variants, named ITGA6A and ITGA6B. In primary human colorectal cancer cells, the levels of both ITGA6 and ß4 integrin subunit (ITGB4) subunits of the α6ß4 integrin are increased. We previously found that the upregulation of ITGA6 is a direct consequence of the increase of the pro-proliferative ITGA6A variant. However, the mechanisms that control ITGA6 expression and splicing into the ITGA6A variant over ITGA6B in colorectal cancer cells remain poorly understood. Here, we show that the promoter activity of the ITGA6 gene is regulated by MYC. Pharmacological inhibition of MYC activity with the MYC inhibitor (MYCi) 10058-F4 or knockdown of MYC expression by short hairpin RNA (shRNA) both lead to a decrease in ITGA6 and ITGA6A levels in colorectal cancer cells, while overexpression of MYC enhances ITGA6 promoter activity. We also found that MYC inhibition decreases the epithelial splicing regulatory protein 2 (ESRP2) splicing factor at both the mRNA and protein levels. Chromatin immunoprecipitation revealed that the proximal promoter sequences of ITGA6 and ESRP2 were occupied by MYC and actively transcribed in colorectal cancer cells. Furthermore, expression studies in primary colorectal tumors and corresponding resection margins confirmed that the up-regulation of the ITGA6A subunit can be correlated with the increase in MYC and ESRP2. Taken together, our results demonstrate that the proto-oncogene MYC can regulate the promoter activation and splicing of the ITGA6 integrin gene through ESRP2 to favor the production of the pro-proliferative ITGA6A variant in colorectal cancer cells.

13.
Biochem Biophys Res Commun ; 495(1): 1510-1515, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29198708

RESUMO

Interactions between cells and the extracellular matrix regulate a wide range of cell processes such as proliferation and differentiation. Laminins are major components of the basement membrane that actively participate in most biological functions via their interactions with a variety of specific cell receptors. The α5-containing laminins (LAMA5) are one of the three main types of laminins identified at the epithelial basal lamina in the adult intestine. The aim of the present study was to investigate the role of α5-containing laminins on intestinal cell proliferation and differentiation. Using an shRNA targeting approach, the effects of knocking down the expression of LAMA5 were investigated in the enterocytic-like Caco-2/15 cell line, a well-characterized model for intestinal cell differentiation. Surprisingly, the abolition of the laminin α5 chain resulted in a drastic increase in the differentiation marker sucrase-isomaltase which was correctly expressed at the apical pole of the cells as observed by indirect immunofluorescence. Transient increases of dipeptidylpeptidase IV, villin, CDX2, HNF-1α, HNF-4α and transepithelial resistance as well as an apparent redistribution of the junctional components ZO-1 and E-cadherin were also observed at early stages of differentiation but no specific effect was observed on cell proliferation as evaluated by BrdU incorporation. Taken together, these data suggest that α5-containing laminins repress intestinal differentiation in its early stages.


Assuntos
Diferenciação Celular/fisiologia , Enterócitos/citologia , Enterócitos/fisiologia , Proteínas da Matriz Extracelular/metabolismo , Intestinos/citologia , Laminina/metabolismo , Animais , Células CACO-2 , Proliferação de Células/fisiologia , Técnicas de Silenciamento de Genes , Humanos , Intestinos/fisiologia
14.
Cancers (Basel) ; 9(8)2017 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-28933766

RESUMO

Integrins are a family of heterodimeric glycoproteins involved in bidirectional cell signaling that participate in the regulation of cell shape, adhesion, migration, survival and proliferation. The integrin α1ß1 is known to be involved in RAS/ERK proliferative pathway activation and plays an important role in fibroblast proliferation. In the small intestine, the integrin α1 subunit is present in the crypt proliferative compartment and absent in the villus. We have recently shown that the integrin α1 protein and transcript (ITGA1) are present in a large proportion of colorectal cancers (CRC) and that their expression is controlled by the MYC oncogenic factor. Considering that α1 subunit/ITGA1 expression is correlated with MYC in more than 70% of colon adenocarcinomas, we postulated that the integrin α1ß1 has a pro-tumoral contribution to CRC. In HT29, T84 and SW480 CRC cells, α1 subunit/ITGA1 knockdown resulted in a reduction of cell proliferation associated with an impaired resistance to anoikis and an altered cell migration in HT29 and T84 cells. Moreover, tumor development in xenografts was reduced in HT29 and T84 sh-ITGA1 cells, associated with extensive necrosis, a low mitotic index and a reduced number of blood vessels. Our results show that α1ß1 is involved in tumor cell proliferation, survival and migration. This finding suggests that α1ß1 contributes to CRC progression.

15.
World J Gastroenterol ; 23(16): 2891-2898, 2017 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-28522907

RESUMO

AIM: To investigate the use of droplet digital polymerase chain reaction (ddPCR) for detecting host mRNA markers in stools as a non-invasive test for colorectal cancer screening. METHODS: ddPCR and quantitative PCR were compared side by side for their performance in the detection of ITGA6 and ITGA6A transcripts in stool samples obtained from patients with various types of colorectal lesions (advanced adenomas and stage II-IV colorectal cancers) and control (patients displaying no pathological findings) using duplex TaqMan reactions for both methods. ITGA6 and ITGA6A were chosen for this proof-of-concept study based on their relative medium and low abundance in stool samples, respectively, as established in a previous study. RESULTS: We found that the ddPCR and qPCR methods performed equally well in this TaqMan duplex assay for the detection of ITGA6 and ITGA6A transcripts in stools of patients with colorectal lesions. For ITGA6, receiver operating characteristic (ROC) curve analysis showed comparable areas under the curve of 0.91 (P < 0.0001) and 0.89-0.90 (P < 0.0001) for the prediction of advanced adenomas and colorectal cancers, respectively. ITGA6A, which was detected at very low levels in control patients, was found to be significantly elevated (over 40 times) in stage II and III colorectal cancers (P < 0.0002). Comparison of the two sets of data revealed a strong correlation of the copy numbers obtained by ddPCR and qPCR for both ITGA6 and ITGA6A. CONCLUSION: We found that ITGA6 and ITGA6A detection in stools of patients with colorectal cancers with ddPCR is comparable to that of qPCR using TaqMan assays.


Assuntos
Adenoma/genética , Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Fezes/química , Integrina alfa6/genética , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/genética , RNA Neoplásico/genética , Adenoma/patologia , Área Sob a Curva , Estudos de Casos e Controles , Neoplasias Colorretais/patologia , Humanos , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Curva ROC , Reprodutibilidade dos Testes
16.
Nitric Oxide ; 66: 53-61, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28315470

RESUMO

BACKGROUND AND AIM: NO synthase 2 (NOS2) was recently identified as one the most overexpressed genes in intestinal samples of premature infants with necrotizing enterocolitis (NEC). NOS2 is widely implicated in the processes of epithelial cell injury/apoptosis and host immune defense but its specific role in inflammation of the immature human intestinal mucosa remains unclear. Interestingly, factors that prevent NEC such as epidermal growth factor (EGF) attenuate the inflammatory response in the mid-gestation human small intestine using serum-free organ culture while drugs that are associated with NEC occurrence such as the non-steroidal anti-inflammatory drug, indomethacin (INDO), exert multiple detrimental effects on the immature human intestine. In this study we investigate the potential role of NOS2 in modulating the gut inflammatory response under protective and stressful conditions by determining the expression profile of NOS2 and its downstream pathways in the immature intestine. METHODS: Gene expression profiles of cultured mid-gestation human intestinal explants were investigated in the absence or presence of a physiological concentration of EGF (50 ng/ml) or 1 µM INDO for 48 h using Illumina whole genome microarrays, Ingenuity Pathway Analysis software and quantitative PCR to investigate the expression of NOS2 and NOS2-pathway related genes. RESULTS: In the immature intestine, NOS2 expression was found to be increased by EGF and repressed by INDO. Bioinformatic analysis identified differentially regulated pathways where NOS2 is known to play an important role including citrulline/arginine metabolism, epithelial cell junctions and oxidative stress. At the individual gene level, we identified many differentially expressed genes of the citrulline/arginine metabolism pathway such as ARG1, ARG2, GLS, OAT and OTC in response to EGF and INDO. Gene expression of tight junction components such as CLDN1, CLDN2, CLDN7 and OCN and of antioxidant markers such as DUOX2, GPX2, SOD2 were also found to be differentially modulated by EGF and INDO. CONCLUSION: These results suggest that the protective effect of EGF and the deleterious influence of INDO on the immature intestine could be mediated via regulation of NOS2. Pathways downstream of NOS2 involved with these effects include metabolism linked to NO production, epithelial barrier permeability and antioxidant expression. These results suggest that NOS2 is a likely regulator of the inflammatory response in the immature human gut and may provide a mechanistic basis for the protective effect of EGF and the deleterious effects of INDO.


Assuntos
Anti-Inflamatórios/farmacologia , Íleo/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Transdução de Sinais/efeitos dos fármacos , Arginina/metabolismo , Citrulina/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Pesquisa Fetal , Fármacos Gastrointestinais/farmacologia , Humanos , Íleo/efeitos dos fármacos , Íleo/enzimologia , Indometacina/farmacologia , Óxido Nítrico Sintase Tipo II/análise , Técnicas de Cultura de Órgãos
17.
PLoS One ; 11(11): e0166138, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27902700

RESUMO

CONTEXT: Lactoferrin (Lf) is an important protein found on mucosal surfaces, within neutrophils and various cells, and in biological fluids. It displays multiple functions, including iron-binding as well as antimicrobial, immunomodulatory and anti-inflammatory activities. Although Lf ingestion has been suggested to cause adiposity reduction in murine models and humans, its relationship with insulin resistance (IR) has not been studied thoroughly. OBJECTIVE: To establish the association between circulating Lf levels, glucose status and blood lipid/lipoprotein profile. METHODS: Two independent cohorts were examined: lean to moderately obese women admitted for gynecological surgery (n = 53) and severely obese subjects undergoing biliopancreatic diversion (n = 62). RESULTS: Although body mass index (BMI) and total body fat mass were negatively associated with Lf, IR (assessed by the HOMA-IR index) was positively and independently associated with plasma Lf concentrations of the first cohort of lean to moderately obese women. These observations were validated in the second cohort in view of the positive correlation between plasma Lf concentrations and the HOMA-IR index, but without a significant association with the body mass index (BMI) of severely obese subjects. In subsamples of severely obese subjects matched for sex, age and BMI, but with either relatively low (1.89 ± 0.73) or high (13.77 ± 8.81) IR states (according to HOMA-IR), higher plasma Lf levels were noted in insulin-resistant vs insulin-sensitive subjects (P<0.05). Finally, Lf levels were significantly higher in lean to moderately obese women than in severely obese subjects (P<0.05). CONCLUSION: Our findings revealed that plasma Lf levels are strongly associated with IR independently of total adiposity, which suggests an intriguing Lf regulation mechanism in conditions of obesity and IR.


Assuntos
Adiposidade/fisiologia , Biomarcadores/sangue , Resistência à Insulina , Lactoferrina/sangue , Obesidade/fisiopatologia , Magreza/fisiopatologia , Adulto , Glicemia/metabolismo , Estudos de Coortes , Feminino , Humanos , Lipídeos/sangue , Lipoproteínas/sangue , Masculino , Pessoa de Meia-Idade
18.
Clin Sci (Lond) ; 130(23): 2217-2237, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27630205

RESUMO

Diets rich in fruits and vegetables may reduce oxidative stress (OxS) and inflammation via several mechanisms. These beneficial effects may be due to their high polyphenol content. The aims of the present study are to evaluate the preventive and therapeutic aspects of polyphenols in dried apple peel powder (DAPP) on intestinal inflammation while elucidating the underlying mechanisms and clinical benefits. Induction of intestinal inflammation in mice was performed by oral administration of the inflammatory agent dextran sulfate sodium (DSS) at 2.5% for 10 days. Physiological and supraphysiological doses of DAPP (200 and 400 mg/kg/day respectively) were administered by gavage for 10 days pre- and post-DSS treatment. DSS-mediated inflammation caused weight loss, shortening of the colon, dystrophic detachment of the epithelium, and infiltration of mono- and poly-morphonuclear cells in the colon. DSS induced an increase in lipid peroxidation, a down-regulation of antioxidant enzymes, an augmented expression of myeloperoxidase (MPO) and cyclooxygenase-2 (COX-2), an elevated production of prostaglandin E2 (PGE2) and a shift in mucosa-associated microbial composition. However, DAPP normalized most of these abnormalities in preventive or therapeutic situations in addition to lowering inflammatory cytokines while stimulating antioxidant transcription factors and modulating other potential healing pathways. The supraphysiological dose of DAPP in therapeutic situations also improved mitochondrial dysfunction. Relative abundance of Peptostreptococcaceae and Enterobacteriaceae bacteria was slightly decreased in DAPP-treated mice. In conclusion, DAPP exhibits powerful antioxidant and anti-inflammatory action in the intestine and is associated with the regulation of cellular signalling pathways and changes in microbiota composition. Evaluation of preventive and therapeutic effects of DAPP may be clinically feasible in individuals with intestinal inflammatory bowel diseases.


Assuntos
Anti-Inflamatórios/administração & dosagem , Frutas/química , Doenças Inflamatórias Intestinais/tratamento farmacológico , Malus/química , Extratos Vegetais/administração & dosagem , Polifenóis/administração & dosagem , Animais , Antioxidantes/administração & dosagem , Ciclo-Oxigenase 2/metabolismo , Humanos , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo
19.
Heliyon ; 2(5): e00109, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27441280

RESUMO

The Hedgehog (HH) signaling pathway is involved in the maintenance of numerous cell types both during development and in the adult. Often deregulated in cancers, its involvement in colorectal cancer has come into view during the last few years, although its role remains poorly defined. In most tissues, the HH pathway is highly connected to the primary cilium (PC), an organelle that recruits functional components and regulates the HH pathway. However, normal epithelial cells of the colon display an inactive HH pathway and lack a PC. In this study, we report the presence of the PC in adenocarcinoma cells of primary colorectal tumors at all stages. Using human colorectal cancer cell lines we found a clear correlation between the presence of the PC and the expression of the final HH effector, GLI1, and provide evidence of a functional link between the two by demonstrating the recruitment of the SMO receptor to the membrane of the primary cilium. We conclude that the primary cilium directly participates in the HH pathway in colorectal cancer cells.

20.
J Cell Physiol ; 231(11): 2361-7, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27061836

RESUMO

A controlled balance between cell proliferation and differentiation is essential to maintain normal intestinal tissue renewal and physiology. Such regulation is powered by several intracellular pathways that are translated into the establishment of specific transcription programs, which influence intestinal cell fate along the crypt-villus axis. One important check-point in this process occurs in the transit amplifying zone of the intestinal crypts where different signaling pathways and transcription factors cooperate to manage cellular proliferation and differentiation, before secretory or absorptive cell lineage terminal differentiation. However, the importance of epigenetic modifications such as histone methylation and acetylation in the regulation of these processes is still incompletely understood. There have been recent advances in identifying the impact of histone modifications and chromatin remodelers on the proliferation and differentiation of normal intestinal crypt cells. In this review we discuss recent discoveries on the role of the cellular epigenome in intestinal cell fate, development, and tissue renewal. J. Cell. Physiol. 231: 2361-2367, 2016. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.


Assuntos
Epigênese Genética , Células Epiteliais/citologia , Intestinos/citologia , Animais , Proliferação de Células , Histonas/metabolismo , Humanos , Processamento de Proteína Pós-Traducional
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