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1.
Neuropathol Appl Neurobiol ; 49(1): e12865, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36456471

RESUMO

AIMS: Adult polyglucosan body disease (APBD) is a progressive neurogenetic disorder caused by 1,4-alpha-glucan branching enzyme 1 (GBE1) mutation with an accumulation of polyglucosan bodies (PBs) in the central and peripheral nervous systems as a pathological hallmark. Here, we report two siblings in a family with a GBE1 mutation with prominent frontotemporal lobar degeneration with TAR DNA-binding protein 43 (FTLD-TDP) and ageing-related tau astrogliopathy (ARTAG) copathologies with PBs in the central nervous system. METHODS: Whole-genome sequencing (WGS) followed by Sanger sequencing (SS) was performed on three affected and two unaffected siblings in a pedigree diagnosed with familial frontotemporal dementia. Out of the affected siblings, autopsies were conducted on two cases, and brain samples were used for biochemical and histological analyses. Brain sections were stained with haematoxylin and eosin and immunostained with antibodies against ubiquitin, tau, amyloid ß, α-synuclein, TDP-43 and fused in sarcoma (FUS). RESULTS: A novel single nucleotide deletion in GBE1, c.1280delG, was identified, which is predicted to result in a reading frameshift, p.Gly427Glufs*9. This variant segregated with disease in the family, is absent from population databases and is predicted to cause loss of function, a known genetic mechanism for APBD. The affected siblings showed a greater than 50% decrease in GBE protein levels. Immunohistochemical analysis revealed widespread FTLD-TDP (type A) and ARTAG pathologies as well as PBs in the brains of two affected siblings for whom an autopsy was performed. CONCLUSIONS: This is the first report of a family with several individuals with a FTD clinical phenotype and underlying copathologies of APBD, FTLD-TDP and ARTAG with a segregating GBE1 loss-of-function mutation in affected siblings. The finding of copathologies of APBD and FTLD-TDP suggests these processes may share a disease mechanism resulting from this GBE1 mutation.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana , Demência Frontotemporal , Degeneração Lobar Frontotemporal , Sistema da Enzima Desramificadora do Glicogênio , Humanos , Demência Frontotemporal/patologia , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Peptídeos beta-Amiloides/metabolismo , Degeneração Lobar Frontotemporal/patologia , Encéfalo/patologia , Mutação , Proteínas de Ligação a DNA/metabolismo , Proteínas tau/metabolismo , Sistema da Enzima Desramificadora do Glicogênio/genética , Sistema da Enzima Desramificadora do Glicogênio/metabolismo
2.
Neoplasia ; 10(1): 8-19, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18231635

RESUMO

The Caudal-related homeobox genes Cdx1 and Cdx2 are intestine-specific transcription factors that regulate differentiation of intestinal cell types. Previously, we have shown Cdx1 to be antiproliferative and to promote cell differentiation. However, other studies have suggested that Cdx1 may be an oncogene. To test for oncogenic behavior, we used the murine villin promoter to ectopically express Cdx1 in the small intestinal villi and colonic surface epithelium. No changes in intestinal architecture, cell differentiation, or lineage selection were observed with expression of the transgene. Classic oncogenes enhance proliferation and induce tumors when ectopically expressed. However, the Cdx1 transgene neither altered intestinal proliferation nor induced spontaneous intestinal tumors. In a murine model for colitis-associated cancer, the Cdx1 transgene decreased, rather than increased, the number of adenomas that developed. In the polyps, the expression of the endogenous and the transgenic Cdx1 proteins was largely absent, whereas endogenous Villin expression was retained. This suggests that transgene silencing was specific and not due to a general Villin inactivation. In conclusion, neither the ectopic expression of Cdx1 was associated with changes in intestinal cell proliferation or differentiation nor was there increased intestinal cancer susceptibility. Our results therefore suggest that Cdx1 is not an oncogene in normal intestinal epithelium.


Assuntos
Transformação Celular Neoplásica/genética , Neoplasias do Colo/genética , Proteínas de Homeodomínio/metabolismo , Mucosa Intestinal/metabolismo , Oncogenes , Fatores de Transcrição/metabolismo , Animais , Fator de Transcrição CDX2 , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Colo/química , Colo/metabolismo , Colo/patologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Proteínas de Homeodomínio/análise , Proteínas de Homeodomínio/genética , Mucosa Intestinal/patologia , Intestinos/química , Intestinos/patologia , Camundongos , Camundongos Transgênicos , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Fatores de Transcrição/análise , Fatores de Transcrição/genética
3.
FASEB J ; 21(14): 3853-65, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17622569

RESUMO

Intestinal epithelial integrity and polarity are maintained by cohesive interactions between cells via the formation of tight junctions. Irregularities in tight junctions have only recently been found to be associated with the initiation and progression of intestinal neoplasia. The claudin family of proteins is integral to the structure and function of the tight junction but little is known of the molecular events that regulate the expression of these components. The present report identifies cathepsin L, classically a lysosomal cysteine protease, as being induced during intestinal epithelial cell polarization and differentiation. Inhibition of intracellular cathepsin L activity results in the accumulation of disorganized cell layers and a decline in the expression of differentiation markers in cultured intestinal epithelial cells. This coincides with a rapid up-regulation of claudin-1 protein accumulation. Mutant mice defective in cathepsin L activity (furless) display an elevated level of intestinal claudin-1 and claudin-2 expression. Loss of cathepsin L activity leads to a marked increase in tumor multiplicity in the intestine of Apc(Min) mice. Given the traditionally viewed biological role of cathepsin L in the processing of lysosomal content as well as in pathological extracellular matrix remodeling, the results here demonstrate an as yet unsuspected intracellular role for this protease in normal intestinal epithelial polarization and initiation of neoplasia.


Assuntos
Catepsinas/antagonistas & inibidores , Catepsinas/metabolismo , Cisteína Endopeptidases/metabolismo , Neoplasias Intestinais/etiologia , Neoplasias Intestinais/genética , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Animais , Sequência de Bases , Células CACO-2 , Catepsina L , Catepsinas/deficiência , Catepsinas/genética , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Linhagem Celular , Claudina-1 , Cisteína Endopeptidases/deficiência , Cisteína Endopeptidases/genética , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Predisposição Genética para Doença , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/enzimologia , Neoplasias Intestinais/metabolismo , Proteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Dados de Sequência Molecular , Inibidores de Proteases/farmacologia , Coelhos , Regulação para Cima/fisiologia
4.
J Biol Chem ; 279(35): 36865-75, 2004 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-15215241

RESUMO

The cessation of proliferation and the induction of differentiation are highly coordinated processes that occur continuously in the intestinal crypts. The homeodomain transcription factors Cdx1 and Cdx2 regulate intestine-specific gene expression and enterocyte differentiation. Their roles in regulating proliferation are recognized but remain poorly understood. Previously, we demonstrated that Cdx1 expression diminished the proliferation of human colon cancer cells in part by reducing cyclin D1 gene expression. In order to elucidate further the molecular mechanisms underlying this phenomenon, we first hypothesized that Cdx1 or Cdx2 expression reduces colon cancer cell proliferation by inhibiting beta-catenin/T-cell factor (TCF) transcriptional activity. We report that Cdx1 or Cdx2 expression does inhibit beta-catenin/TCF transcriptional activity in colon cancer cells. This inhibitory effect is dose-dependent and is observed in different colon cancer cell lines, and the degree of inhibition correlates with the ability of Cdx1 to reduce cell proliferation. Cdx1 expression does not alter beta-catenin protein levels or intracellular distribution nor does it induce an inhibitory TCF isoform. We also find that Cdx1 expression is lost in Min mouse polyps with increased nuclear localization of beta-catenin, suggesting that Cdx1 does not support beta-catenin-mediated transformation. Finally, we show that colon cancer cells effectively reduce Cdx2-mediated inhibition of Wnt/beta-catenin/TCF transcriptional activity when compared with other model systems. This suggests that colon cancer and possibly crypt epithelial cells can modulate the effects of Cdx2 on beta-catenin signaling and proliferation. We conclude that Cdx1 and Cdx2 inhibit colon cancer cell proliferation by blocking beta-catenin/TCF transcriptional activity.


Assuntos
Proteínas Aviárias , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Proteínas do Citoesqueleto/metabolismo , Proteínas de Homeodomínio/fisiologia , Transativadores/metabolismo , Transcrição Gênica , Proteínas de Xenopus , Adenoviridae/genética , Animais , Northern Blotting , Fator de Transcrição CDX2 , Diferenciação Celular , Divisão Celular , Linhagem Celular , Linhagem Celular Tumoral , Ciclina D1/genética , Ciclina D1/metabolismo , Relação Dose-Resposta a Droga , Enterócitos/metabolismo , Regulação da Expressão Gênica , Genes Reporter , Genótipo , Proteínas de Homeodomínio/metabolismo , Humanos , Imuno-Histoquímica , Mucosa Intestinal/metabolismo , Microscopia de Fluorescência , Modelos Biológicos , Fenótipo , Testes de Precipitina , Regiões Promotoras Genéticas , Isoformas de Proteínas , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Mensageiro/metabolismo , Ribonucleases/metabolismo , Transdução de Sinais , Transfecção , Xenopus , beta Catenina
5.
Cancer Biol Ther ; 3(7): 593-601, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15136761

RESUMO

Since their original identification in Drosophila, the caudal related homologues (Cdx1 and Cdx2) have been known to be evolutionarily conserved both in molecular structure and function. In a great variety of organisms they are recognized to function critically during antero-posterior patterning and the development of the intestinal epithelium. The Cdx homologues, when expressed, modulate a diverse set of processes including proliferation, apoptosis, cell-adhesion, and columnar morphology. They are also necessary for the expression of an increasing number of intestine-specific genes. By targeting these processes and genes, the Cdx homologues promote the appearance of a mature intestinal cell phenotype. In addition to these critical roles during development, accumulating evidence suggests that the Cdx homologues may play significant roles in oncogenesis in the gastrointestinal tract and other tissues. In the colon, several studies suggest the Cdx homologues may act as tumor suppressors. However, ectopic Cdx1 and Cdx2 expression is involved in the development of the precancerous intestinal metaplasia in the stomach and esophagus, and may be a transforming event in one form of acute myelogenous leukemia. This review will explore our current understanding of the roles of the caudal homologues Cdx1 and Cdx2 in intestinal development and carcinogenesis.


Assuntos
Neoplasias do Colo/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/metabolismo , Mucosa Intestinal/metabolismo , Fator de Transcrição CDX2 , Neoplasias do Colo/patologia , Progressão da Doença , Humanos , Mucosa Intestinal/patologia
6.
Mol Cell Biol ; 22(15): 5467-78, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12101240

RESUMO

Intestinal gene regulation involves mechanisms that direct temporal expression along the vertical and horizontal axes of the alimentary tract. Sucrase-isomaltase (SI), the product of an enterocyte-specific gene, exhibits a complex pattern of expression. Generation of transgenic mice with a mutated SI transgene showed involvement of an overlapping CDP (CCAAT displacement protein)-GATA element in colonic repression of SI throughout postnatal intestinal development. We define this element as CRESIP (colon-repressive element of the SI promoter). Cux/CDP interacts with SI and represses SI promoter activity in a CRESIP-dependent manner. Cux/CDP homozygous mutant mice displayed increased expression of SI mRNA during early postnatal development. Our results demonstrate that an intestinal gene can be repressed in the distal gut and identify Cux/CDP as a regulator of this repression during development.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Mucosa Intestinal/metabolismo , Proteínas Nucleares/metabolismo , Sequências Reguladoras de Ácido Nucleico/fisiologia , Proteínas Repressoras/metabolismo , Complexo Sacarase-Isomaltase/genética , Envelhecimento/metabolismo , Animais , Células COS , Células CACO-2 , Colo/citologia , Colo/crescimento & desenvolvimento , Colo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fator de Transcrição GATA4 , Proteínas de Homeodomínio , Humanos , Hibridização In Situ , Intestino Delgado/citologia , Intestino Delgado/crescimento & desenvolvimento , Intestino Delgado/metabolismo , Intestinos/citologia , Intestinos/crescimento & desenvolvimento , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas/fisiologia , RNA Mensageiro/metabolismo , Complexo Sacarase-Isomaltase/biossíntese , Fatores de Transcrição/metabolismo , Transgenes
7.
J Biol Chem ; 277(39): 35795-800, 2002 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-12124393

RESUMO

CDX1 is a homeobox protein that inhibits proliferation of intestinal epithelial cells and regulates intestine-specific genes involved in differentiation. CDX1 expression is developmentally and spatially regulated, and its expression is aberrantly down-regulated in colorectal cancers and colon cancer-derived cell lines. However, very little is known about the molecular mechanism underlying the regulation of CDX1 gene expression. In this study, we characterized the CDX1 gene structure and identified that its gene promoter contained a typical CpG island with a CpG observed/expected ratio of 0.80, suggesting that the CDX1 gene is a target of aberrant methylation. Alterations of DNA methylation in the CDX1 gene promoter were investigated in a series of colorectal cancer cell lines. Combined Bisulfite Restriction Analysis (COBRA) and bisulfite sequencing analysis revealed that the CDX1 promoter is methylated in CDX1 non-expressing colorectal cancer cell lines but not in human normal colon tissue and T84 cells, which express CDX1. Treatment with 5'-aza-2'-deoxycytidine (5-azaC), a DNA methyltransferase inhibitor, induced CDX1 expression in the colorectal cancer cell lines. Furthermore, de novo methylation was determined by establishing stably transfected clones of the CDX1 promoter in SW480 cells and demethylation by 5-azaC-activated reporter gene expression. These results indicate that aberrant methylation of the CpG island in the CDX1 promoter is one of the mechanisms that mediate CDX1 down-regulation in colorectal cancer cell lines.


Assuntos
Azacitidina/análogos & derivados , Neoplasias Colorretais/genética , Metilação de DNA , Regulação para Baixo , Animais , Azacitidina/farmacologia , Sequência de Bases , Western Blotting , Clonagem Molecular , Neoplasias Colorretais/metabolismo , Cosmídeos/metabolismo , Ilhas de CpG , Decitabina , Inibidores Enzimáticos/farmacologia , Células HeLa , Humanos , Camundongos , Dados de Sequência Molecular , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfitos/farmacologia , Transfecção , Células Tumorais Cultivadas
8.
J Biol Chem ; 277(35): 31909-17, 2002 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-12060663

RESUMO

Sucrase-isomaltase (SI), an intestine-specific gene, is induced in the differentiated small intestinal villous epithelium during the suckling-weaning transition in mice. We have previously identified cis-acting elements within a short evolutionarily conserved SI promoter. However, the nature and profile of expression of the interacting proteins have not been fully characterized during this developmental transition. Herein, we show that hepatocyte nuclear factor-1 alpha (HNF-1 alpha), GATA-4, and caudal related homeodomain proteins Cdx2 and Cdx1 are the primary transcription factors from the adult mouse intestinal epithelium to interact with the SIF3, GATA, and SIF1 elements of the SI promoter. We wanted to study whether HNF-1 alpha, GATA-4, and Cdx2 can cooperate in the regulation of SI gene expression. Immunolocalization experiments revealed that HNF-1 alpha is detected in rare epithelial cells of suckling mice and becomes progressively more expressed in the villous epithelial cells during the suckling-weaning transition. GATA-4 protein is expressed exclusively in villous differentiated epithelial cells of the proximal small intestine, decreases in expression in the ileum, and becomes undetectable in the colon. HNF-1 alpha, GATA-4, and Cdx2 interact in vitro and in vivo. These factors activate SI promoter activity in cotransfection experiments where GATA-4 requires the presence of both HNF-1 alpha and Cdx2. These findings imply a combinatory role of HNF-1 alpha, Cdx2, and GATA-4 for the time- and position-dependent regulation of SI transcription during development.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Mucosa Intestinal/enzimologia , Proteínas Nucleares , Complexo Sacarase-Isomaltase/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Animais , Sequência de Bases , Fator de Transcrição CDX2 , Fator de Transcrição GATA4 , Genes Reporter , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Fator 1-beta Nuclear de Hepatócito , Mucosa Intestinal/crescimento & desenvolvimento , Luciferases/genética , Camundongos , Camundongos Transgênicos , Microvilosidades/enzimologia , Regiões Promotoras Genéticas , Transativadores , Dedos de Zinco
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