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1.
Dev Biol ; 480: 50-61, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34411593

RESUMEN

During postnatal intestinal development, the intestinal epithelium is highly proliferative, and this proliferation is regulated by signaling in the intervillous and crypt regions. This signaling is primarily mediated by Wnt, and requires membrane trafficking. However, the mechanisms by which membrane trafficking regulates signaling during this developmental phase are largely unknown. Endotubin (EDTB, MAMDC4) is an endosomal protein that is highly expressed in the apical endocytic complex (AEC) of villus enterocytes during fetal and postnatal development, and knockout of EDTB results in defective formation of the AEC and giant lysosome. Further, knockout of EDTB in cell lines results in decreased proliferation. However, the role of EDTB in proliferation during the development of the intestine is unknown. Using Villin-CreERT2 in EDTBfl/fl mice, we deleted EDTB in the intestine in the early postnatal period, or in enteroids in vitro after isolation of intervillous cells. Loss of EDTB results in decreased proliferation in the developing intestinal epithelium and decreased ability to form enteroids. EDTB is present in cells that contain the stem cell markers LGR5 and OLFM4, indicating that it is expressed in the proliferative compartment. Further, using immunoblot analysis and TCF/LEF-GFP mice as a reporter of Wnt activity, we find that knockout of EDTB results in decreased Wnt signaling. Our results show that EDTB is essential for normal proliferation during the early stages of intestinal development and suggest that this effect is through modulation of Wnt signaling.


Asunto(s)
Proliferación Celular/genética , Glicoproteínas/genética , Intestinos/embriología , Animales , Diferenciación Celular/genética , Proliferación Celular/fisiología , Endosomas/metabolismo , Enterocitos/metabolismo , Femenino , Glicoproteínas/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/metabolismo , Masculino , Ratones , Ratones Noqueados , Proteínas de Microfilamentos/genética , Proteínas Wnt/metabolismo , Vía de Señalización Wnt/fisiología
2.
J Virol ; 95(11)2021 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-33762413

RESUMEN

Human cytomegalovirus (HCMV), while highly restricted for the human species, infects an diverse array of cell types in the host. Patterns of infection are dictated by the cell type infected, but cell type-specific factors and how they impact tropism for specific cell types is poorly understood. Previous studies in primary endothelial cells showed that HCMV infection induces large multivesicular-like bodies (MVBs) that incorporate viral products, including dense bodies (DBs) and virions. Here we define the nature of these large vesicles using a recombinant virus where UL32, encoding the pp150 tegument protein, is fused in frame with green fluorescent protein (GFP, TB40/E-UL32-GFP). In fibroblasts, UL32-GFP-positive vesicles were marked with classical markers of MVBs, including CD63 and lysobisphosphatidic acid (LBPA), both classical MVB markers, as well as the clathrin and LAMP1. Unexpectedly, UL32-GFP-positive vesicles in primary human microvascular endothelial cells (HMVECs) were not labeled by CD63, and LBPA was completely lost from infected cells. We defined these UL32-positive vesicles in endothelial cells using markers for the cis-Golgi (GM130), lysosome (LAMP1), and autophagy (LC3B). These findings suggest that UL32-GFP containing MVBs in fibroblasts are derived from the canonical endocytic pathway and takeover classical exosomal release pathway. However, UL32-GFP containing MVBs in HMVECs are derived from the early biosynthetic pathway and exploit a less characterized early Golgi-LAMP1-associated non- canonical secretory autophagy pathway. These results reveal striking cell-type specific membrane trafficking differences in host pathways that are exploited by HCMV, which may reflect distinct pathways for virus egress.ImportanceHuman cytomegalovirus (HCMV) is a herpesvirus that, like all herpesvirus, that establishes a life-long infection. HCMV remains a significant cause of morbidity and mortality in the immunocompromised and HCMV seropositivity is associated with age-related pathology. HCMV infects many cells in the human host and the biology underlying the different patterns of infection in different cell types is poorly understood. Endothelial cells are important target of infection that contribute to hematogenous spread of the virus to tissues. Here we define striking differences in the biogenesis of large vesicles that incorporate virions in fibroblasts and endothelial cells. In fibroblasts, HCMV is incorporated into canonical MVBs derived from an endocytic pathway, whereas HCMV matures through vesicles derived from the biosynthetic pathway in endothelial cells. This work defines basic biological differences between these cell types that may impact how progeny virus is trafficked out of infected cells.

3.
Gastroenterology ; 159(4): 1342-1356.e6, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32589883

RESUMEN

BACKGROUND & AIMS: Intestinal epithelial cells (IECs) provide a barrier that separates the mucosal immune system from the luminal microbiota. IECs constitutively express low levels of major histocompatibility complex (MHC) class II proteins, which are upregulated upon exposure to interferon gamma. We investigated the effects of deleting MHCII proteins specifically in mice with infectious, dextran sodium sulfate (DSS)-, and T-cell-induced colitis. METHODS: We disrupted the histocompatibility 2, class II antigen A, beta 1 gene (H2-Ab1) in IECs of C57BL/6 mice (I-AbΔIEC) or Rag1-/- mice (Rag1-/-I-AbΔIEC); we used I-AbWT mice as controls. Colitis was induced by administration of DSS, transfer of CD4+CD45RBhi T cells, or infection with Citrobacter rodentium. Colon tissues were collected and analyzed by histology, immunofluorescence, xMAP, and reverse-transcription polymerase chain reaction and organoids were generated. Microbiota (total and immunoglobulin [Ig]A-coated) in intestinal samples were analyzed by16S amplicon profiling. IgA+CD138+ plasma cells from Peyer's patches and lamina propria were analyzed by flow cytometry and IgA repertoire was determined by next-generation sequencing. RESULTS: Mice with IEC-specific loss of MHCII (I-AbΔIEC mice) developed less severe DSS- or T-cell transfer-induced colitis than control mice. Intestinal tissues from I-AbΔIEC mice had a lower proportion of IgA-coated bacteria compared with control mice, and a reduced luminal concentration of secretory IgA (SIgA) following infection with C rodentium. There was no significant difference in the mucosal IgA repertoire of I-AbΔIEC vs control mice, but opsonization of cultured C rodentium by SIgA isolated from I-AbΔIEC mice was 50% lower than that of SIgA from mAbWT mice. Fifty percent of I-AbΔIEC mice died after infection with C rodentium, compared with none of the control mice. We observed a transient but significant expansion of the pathogen in the feces of I-AbΔIEC mice compared with I-AbWT mice. CONCLUSIONS: In mice with DSS or T-cell-induced colitis, loss of MHCII from IECs reduces but does not eliminate mucosal inflammation. However, in mice with C rodentium-induced colitis, loss of MHCII reduces bacterial clearance by decreasing binding of IgA to commensal and pathogenic bacteria.


Asunto(s)
Colitis/etiología , Colitis/patología , Células Epiteliales/metabolismo , Células Epiteliales/patología , Antígenos de Histocompatibilidad Clase II/metabolismo , Mucosa Intestinal/patología , Animales , Colitis/metabolismo , Modelos Animales de Enfermedad , Mucosa Intestinal/metabolismo , Ratones , Ratones Endogámicos C57BL
4.
BMC Gastroenterol ; 21(1): 132, 2021 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-33752610

RESUMEN

BACKGROUND: The SCCAI was designed to facilitate assessment of disease activity in ulcerative colitis (UC). We aimed to interrogate the metric properties of individual items of the SCCAI using item response theory (IRT) analysis, to simplify and improve its performance. METHODS: The original 9-item SCCAI was collected through TrueColours, a real-time software platform which allows remote entry and monitoring of patients with UC. Data were securely uploaded onto Dementias Platform UK Data Portal, where they were analysed in Stata 16.1 SE. A 2-parameter (2-PL) logistic IRT model was estimated to evaluate each item of the SCCAI for its informativeness (discrimination). A revised scale was generated and re-assessed following systematic removal of items. RESULTS: SCCAI data for 516 UC patients (41 years, SD = 15) treated in Oxford were examined. After initial item deletion (Erythema nodosum, Pyoderma gangrenosum), a 7-item scale was estimated. Discrimination values (information) ranged from 0.41 to 2.52 indicating selected item inefficiency with three items < 1.70 which is a suggested discriminatory value for optimal efficiency. Systematic item deletions found that a 4-item scale (bowel frequency day; bowel frequency nocturnal; urgency to defaecation; rectal bleeding) was more informative and discriminatory of trait severity (discrimination values of 1.50 to 2.78). The 4-item scale possesses higher scalability and unidimensionality, suggesting that the responses to items are either direct endorsement (patient selection by symptom) or non-endorsement of the trait (disease activity). CONCLUSION: Reduction of the SCCAI from the original 9-item scale to a 4-item scale provides optimum trait information that will minimise response burden. This new 4-item scale needs validation against other measures of disease activity such as faecal calprotectin, endoscopy and histopathology.


Asunto(s)
Colitis Ulcerosa , Piodermia Gangrenosa , Colitis Ulcerosa/diagnóstico , Heces , Humanos , Complejo de Antígeno L1 de Leucocito , Índice de Severidad de la Enfermedad
5.
J Cell Sci ; 130(14): 2405-2415, 2017 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-28584192

RESUMEN

Endosomal trafficking can influence the composition of the plasma membrane and the ability of cells to polarize their membranes. Here, we examined whether trafficking through clathrin-independent endocytosis (CIE) affects the ability of T cells to form a cell-cell conjugate with antigen-presenting cells (APCs). We show that CIE occurs in both the Jurkat T cell line and primary human T cells. In Jurkat cells, the activities of two guanine nucleotide binding proteins, Arf6 and Rab22 (also known as Rab22a), influence CIE and conjugate formation. Expression of the constitutively active form of Arf6, Arf6Q67L, inhibits CIE and conjugate formation, and results in the accumulation of vacuoles containing lymphocyte function-associated antigen 1 (LFA-1) and CD4, molecules important for T cell interaction with the APC. Moreover, expression of the GTP-binding defective mutant of Rab22, Rab22S19N, inhibits CIE and conjugate formation, suggesting that Rab22 function is required for these activities. Furthermore, Jurkat cells expressing Rab22S19N were impaired in spreading onto coverslips coated with T cell receptor-activating antibodies. These observations support a role for CIE, Arf6 and Rab22 in conjugate formation between T cells and APCs.


Asunto(s)
Factores de Ribosilacion-ADP/metabolismo , Clatrina/metabolismo , Endocitosis/fisiología , Linfocitos T/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Factor 6 de Ribosilación del ADP , Factores de Ribosilacion-ADP/genética , Humanos , Membranas Intracelulares/metabolismo , Células Jurkat , Antígeno-1 Asociado a Función de Linfocito/inmunología , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Transporte de Proteínas , Linfocitos T/citología , Linfocitos T/inmunología , Transfección , Proteínas de Unión al GTP rab/genética
6.
Bioinformatics ; 33(14): i208-i216, 2017 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-28881994

RESUMEN

MOTIVATION: Systems immunology leverages recent technological advancements that enable broad profiling of the immune system to better understand the response to infection and vaccination, as well as the dysregulation that occurs in disease. An increasingly common approach to gain insights from these large-scale profiling experiments involves the application of statistical learning methods to predict disease states or the immune response to perturbations. However, the goal of many systems studies is not to maximize accuracy, but rather to gain biological insights. The predictors identified using current approaches can be biologically uninterpretable or present only one of many equally predictive models, leading to a narrow understanding of the underlying biology. RESULTS: Here we show that incorporating prior biological knowledge within a logistic modeling framework by using network-level constraints on transcriptional profiling data significantly improves interpretability. Moreover, incorporating different types of biological knowledge produces models that highlight distinct aspects of the underlying biology, while maintaining predictive accuracy. We propose a new framework, Logistic Multiple Network-constrained Regression (LogMiNeR), and apply it to understand the mechanisms underlying differential responses to influenza vaccination. Although standard logistic regression approaches were predictive, they were minimally interpretable. Incorporating prior knowledge using LogMiNeR led to models that were equally predictive yet highly interpretable. In this context, B cell-specific genes and mTOR signaling were associated with an effective vaccination response in young adults. Overall, our results demonstrate a new paradigm for analyzing high-dimensional immune profiling data in which multiple networks encoding prior knowledge are incorporated to improve model interpretability. AVAILABILITY AND IMPLEMENTATION: The R source code described in this article is publicly available at https://bitbucket.org/kleinstein/logminer . CONTACT: steven.kleinstein@yale.edu or stefan.avey@yale.edu. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Biología Computacional/métodos , Gripe Humana/prevención & control , Modelos Biológicos , Vacunación , Regulación de la Expresión Génica , Humanos , Sistema Inmunológico , Gripe Humana/genética , Gripe Humana/metabolismo , Transducción de Señal , Transcriptoma
7.
Med Teach ; 40(6): 600-606, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29490531

RESUMEN

Whether ultrasound (US) should be incorporated into a medical undergraduate curriculum remains a matter of debate within the medical education arena. There are clear potential benefits to its early introduction particularly with respect to the study of living anatomy and physiology in addition to the learning of clinical skills and procedures required for the graduate clinical practice. However, this needs to be balanced against what is perceived as an added value in addition to financial and time constraints which may potentially lead to the sacrifice of other aspects of the curriculum. Several medical schools have already reported their experiences of teaching US either as a standalone course or as a fully integrated vertical curriculum. This article describes and discusses the initial experience of a UK medical school that has taken the steps to develop its own pragmatic vertical US curriculum based on clinical endpoints with the intent of using US to enhance the learning experience of students and equipping them with the skills required for the safe practice as a junior doctor.


Asunto(s)
Competencia Clínica , Educación de Pregrado en Medicina/organización & administración , Ultrasonografía/métodos , Curriculum , Humanos , Desarrollo de Programa , Factores de Tiempo , Reino Unido
8.
Pediatr Endocrinol Rev ; 15(2): 147-158, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29292626

RESUMEN

The earliest stages of pregnancy are marked by countless changes in the maternal environment. A specific coordination of activity is required for a successful pregnancy, starting early in the menstrual cycle. Early establishment of maternal-fetal crosstalk is critical for the progression of pregnancy. Many factors, both maternal and fetal derived, play specific and important roles immediately following fertilization, through implantation and beyond. Here we present a review of some of the key factors involved with a focus on PreImplantation Factor (PIF), a small peptide secreted only by competent embryos, which carries an important role required for pregnancy progression.


Asunto(s)
Endocrinología , Femenino , Humanos , Péptidos , Embarazo
9.
Pharmacogenet Genomics ; 26(2): 96-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26551314

RESUMEN

The cytochrome P450 2D6 (CYP2D6) gene is perhaps the most well characterized gene involved in drug metabolism and is known to have both gene duplication and deletion variants that are inheritable and stable. In a set of over 30,000 deidentified clinical samples we found that 12.6% of all patients tested had zero, one, or three or more copies of the CYP2D6 gene. On the basis of the combined frequency and impact of these variants, we believe that CYP2D6 copy number variation may account for the single most impactful genetic anomaly as it relates to pharmacogenetic directed therapies.


Asunto(s)
Citocromo P-450 CYP2D6/genética , Variaciones en el Número de Copia de ADN , Humanos , Estados Unidos
10.
J Virol ; 89(13): 6536-50, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25878111

RESUMEN

UNLABELLED: Endothelial cells (ECs) are a critical target of viruses, and infection of the endothelium represents a defining point in viral pathogenesis. Human cytomegalovirus (HCMV), the prototypical betaherpesvirus, encodes proteins specialized for entry into ECs and delivery of the genome to the nuclei of ECs. Virus strains competent to enter ECs replicate with differing efficiencies, suggesting that the virus encodes genes for postentry tropism in ECs. We previously reported a specific requirement for the UL133/8 locus of HCMV for replication in ECs. The UL133/8 locus harbors four genes: UL133, UL135, UL136, and UL138. In this study, we find that while UL133 and UL138 are dispensable for replication in ECs, both UL135 and UL136 are important. These genes are not required for virus entry or the expression of viral genes. The phenotypes associated with disruption of either gene reflect phenotypes observed for the UL133/8NULL virus, which lacks the entire UL133/8 locus, but are largely distinct from one another. Viruses lacking UL135 fail to properly envelop capsids in the cytoplasm, produce fewer dense bodies (DB) than the wild-type (WT) virus, and are unable to incorporate viral products into multivesicular bodies (MVB). Viruses lacking UL136 also fail to properly envelop virions and produce larger dense bodies than the WT virus. Our results indicate roles for the UL135 and UL136 proteins in commandeering host membrane-trafficking pathways for virus maturation. UL135 and UL136 represent the first HCMV genes crucial for early- to late-stage tropism in ECs. IMPORTANCE: Human cytomegalovirus (HCMV) persists in the majority of the world's population. While typically asymptomatic in healthy hosts, HCMV can cause significant morbidity and mortality in immunocompromised or naïve individuals, particularly transplant patients and patients with congenital infections, respectively. Lifelong persistence of the virus may also contribute to age-related pathologies, such as vascular disease. One aspect of HCMV infection contributing to complex and varied pathogenesis is the diverse array of cell types that this virus infects in the host. The vascular endothelium is a particularly important target of infection, contributing to viral dissemination and likely leading to CMV complications following transplantation. In this work, we identify two viral gene products required for postentry tropism in endothelial cells. Identifying tropism factors required for replication in critical cell targets of infection is important for the development of strategies to restrict virus replication.


Asunto(s)
Citomegalovirus/fisiología , Células Endoteliales/virología , Proteínas Virales/metabolismo , Ensamble de Virus , Replicación Viral , Citomegalovirus/genética , Técnicas de Inactivación de Genes , Humanos , Proteínas Virales/genética
11.
Proc Natl Acad Sci U S A ; 110(35): 14450-5, 2013 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-23940317

RESUMEN

Atypical protein kinase C (aPKC) isoforms ζ and λ interact with polarity complex protein Par3 and are evolutionarily conserved regulators of cell polarity. Prkcz encodes aPKC-ζ and PKM-ζ, a truncated, neuron-specific alternative transcript, and Prkcl encodes aPKC-λ. Here we show that, in embryonic hippocampal neurons, two aPKC isoforms, aPKC-λ and PKM-ζ, are expressed. The localization of these isoforms is spatially distinct in a polarized neuron. aPKC-λ, as well as Par3, localizes at the presumptive axon, whereas PKM-ζ and Par3 are distributed at non-axon-forming neurites. PKM-ζ competes with aPKC-λ for binding to Par3 and disrupts the aPKC-λ-Par3 complex. Silencing of PKM-ζ or overexpression of aPKC-λ in hippocampal neurons alters neuronal polarity, resulting in neurons with supernumerary axons. In contrast, the overexpression of PKM-ζ prevents axon specification. Our studies suggest a molecular model wherein mutually antagonistic intermolecular competition between aPKC isoforms directs the establishment of neuronal polarity.


Asunto(s)
Polaridad Celular/fisiología , Hipocampo/citología , Isoenzimas/metabolismo , Neuronas/citología , Proteína Quinasa C/metabolismo , Animales , Células Cultivadas , Femenino , Isoenzimas/fisiología , Embarazo , Proteína Quinasa C/fisiología , Ratas , Ratas Sprague-Dawley
12.
J Infect Dis ; 211(7): 1174-84, 2015 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-25367297

RESUMEN

We evaluated in vivo innate immune responses in monocyte populations from 67 young (aged 21-30 years) and older (aged ≥65 years) adults before and after influenza vaccination. CD14(+)CD16(+) inflammatory monocytes were induced after vaccination in both young and older adults. In classical CD14(+)CD16(-) and inflammatory monocytes, production of tumor necrosis factor α and interleukin 6, as measured by intracellular staining, was strongly induced after vaccination. Cytokine production was strongly associated with influenza vaccine antibody response; the highest levels were found as late as day 28 after vaccination in young subjects and were substantially diminished in older subjects. Notably, levels of the anti-inflammatory cytokine interleukin 10 (IL-10) were markedly elevated in monocytes from older subjects before and after vaccination. In purified monocytes, we found age-associated elevation in phosphorylated signal transducer and activator of transcription-3, and decreased serine 359 phosphorylation of the negative IL-10 regulator dual-specificity phosphatase 1. These findings for the first time implicate dysregulated IL-10 production in impaired vaccine responses in older adults.


Asunto(s)
Citocinas/metabolismo , Vacunas contra la Influenza/inmunología , Gripe Humana/prevención & control , Interleucina-10/metabolismo , Monocitos/metabolismo , Adulto , Factores de Edad , Anciano , Citocinas/inmunología , Fosfatasa 1 de Especificidad Dual/inmunología , Fosfatasa 1 de Especificidad Dual/metabolismo , Femenino , Proteínas Ligadas a GPI/inmunología , Proteínas Ligadas a GPI/metabolismo , Regulación de la Expresión Génica/inmunología , Humanos , Inmunidad Innata , Gripe Humana/inmunología , Gripe Humana/virología , Interleucina-10/inmunología , Interleucina-6/inmunología , Interleucina-6/metabolismo , Receptores de Lipopolisacáridos/inmunología , Receptores de Lipopolisacáridos/metabolismo , Masculino , Monocitos/inmunología , Fosforilación , Receptores de IgG/inmunología , Receptores de IgG/metabolismo , Factor de Transcripción STAT3/inmunología , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Vacunación , Adulto Joven
13.
Cell Tissue Res ; 360(2): 321-32, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25616555

RESUMEN

GOPC (FIG/PIST/CAL) is a PDZ-domain scaffolding protein that regulates the trafficking of a wide array of proteins, including small GTPases, receptors and cell surface molecules such as cadherin 23 and cystic fibrosis transmembrane regulator. In Madin-Darby canine kidney (MDCK) cells, we find that GOPC localizes to the trans-Golgi network (TGN) but not to the cis- or trans-Golgi cisternae. Colocalization occurs with the early endosome Rab GTPase Rab5 and a TGN/endosome marker Rab14 but not with Rab11, a marker of recycling endosomes. No localization of GOPC was detected to the lateral membranes or tight junctions. Knockdown of GOPC in MDCK cells results in decreased transepithelial resistance and increased paracellular flux. This might be attributable to the compromised trafficking of tight junction components from the TGN, as GOPC-knockdown cells have decreased lateral labeling of the tight junction protein claudin-1 and decreased protein levels of claudin-2. GOPC might mediate the trafficking of newly synthesized tight junction proteins from the TGN to the cell surface or the recycling of these proteins from specialized endosomal compartments.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas de la Membrana/metabolismo , Uniones Estrechas/metabolismo , Animales , Proteínas Portadoras/genética , Perros , Endosomas/genética , Endosomas/metabolismo , Células de Riñón Canino Madin Darby , Proteínas de la Membrana/genética , Transporte de Proteínas/fisiología , Uniones Estrechas/genética , Proteínas de Unión al GTP rab5/genética , Proteínas de Unión al GTP rab5/metabolismo , Red trans-Golgi/genética , Red trans-Golgi/metabolismo
14.
PLoS One ; 19(5): e0296003, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38787854

RESUMEN

Maintenance of the intestinal epithelium requires constant self-renewal and regeneration. Tight regulation of proliferation and differentiation of intestinal stem cells within the crypt region is critical to maintaining homeostasis. The transcriptional co-factors ß-catenin and YAP are required for proliferation during normal homeostasis as well as intestinal regeneration after injury: aberrant signaling activity results in over proliferation and tumorigenesis. Although both YAP and ß-catenin activity are controlled along canonical pathways, it is becoming increasingly clear that non-canonical regulation of these transcriptional regulators plays a role in fine tuning their activity. We have shown previously that MAMDC4 (Endotubin, AEGP), an integral membrane protein present in endosomes, regulates both YAP and ß-catenin activity in kidney epithelial cells and in the developing intestinal epithelium. Here we show that MAMDC4 interacts with members of the signalosome and mediates cross-talk between YAP and ß-catenin. Interestingly, this cross-talk occurs through a non-canonical pathway involving interactions between AMOT:YAP and AMOT:ß-catenin.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Endosomas , Factores de Transcripción , Vía de Señalización Wnt , beta Catenina , Humanos , beta Catenina/metabolismo , Endosomas/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Animales , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Señalizadoras YAP/metabolismo , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Ratones , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Células HEK293 , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Unión Proteica
16.
J Crohns Colitis ; 17(11): 1744-1751, 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-37306285

RESUMEN

BACKGROUND AND AIMS: Digital collection of patient-reported outcome measures [PROMs] is largely unexplored as a basis for follow-up for patients with ulcerative colitis [UC]. Our aim was to develop a model to predict the likelihood of escalation of therapy or intervention at an outpatient appointment that may be used to rationalize follow-up. METHODS: TrueColours-IBD is a web-based, real-time, remote monitoring software that allows longitudinal collection of ePROMs. Data for prediction modelling were derived from a Development Cohort, guided by the TRIPOD statement. Logistic regression modelling used ten candidate items to predict escalation of therapy or intervention. An Escalation of Therapy or Intervention [ETI] calculator was developed, and applied in a Validation Cohort at the same centre. RESULTS: The Development Cohort [n = 66] was recruited in 2016 and followed for 6 months [208 appointments]. From ten items, four significant predictors of ETI were identified: SCCAI, IBD Control-8, faecal calprotectin, and platelets. For practicality, a model with only SCCAI and IBD Control-8, both entered remotely by the patient, without the need for faecal calprotectin or blood tests was selected. Between 2018 and 2020, a Validation Cohort of 538 patients [1188 appointments] was examined. A 5% threshold on the ETI calculator correctly identified 343/388 [88%] escalations and 274/484 [57%] non-escalations. CONCLUSIONS: A calculator based on digital, patient-entered data on symptoms and quality of life can predict whether a patient with UC requires escalation of therapy or intervention at an outpatient appointment. This may be used to streamline outpatient appointments for patients with UC.


Asunto(s)
Colitis Ulcerosa , Humanos , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/terapia , Calidad de Vida , Complejo de Antígeno L1 de Leucocito
17.
Traffic ; 11(6): 856-66, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20214753

RESUMEN

The establishment of tight junctions and cell polarity is an essential process in all epithelia. Endotubin is an integral membrane protein found in apical endosomes of developing epithelia when tight junctions and epithelial polarity first arise. We found that the disruption of endotubin function in cells in culture by siRNA or overexpression of the C-terminal cytoplasmic domain of endotubin causes defects in organization and function of tight junctions. We observe defects in localization of tight junction proteins, reduced transepithelial resistance, increased lanthanum penetration between cells and reduced ability of cells to form cysts in three-dimensional culture. In addition, in cells overexpressing the C-terminal domain of endotubin, we observe a delay in re-establishing the normal distribution of endosomes after calcium switch. These results suggest that endotubin regulates trafficking of polarity proteins and tight junction components out of the endosomal compartment, thereby providing a critical link between a resident protein of apical endosomes and tight junctions.


Asunto(s)
Endosomas/metabolismo , Epitelio/metabolismo , Uniones Estrechas/metabolismo , Animales , Calcio/química , Citoplasma/metabolismo , Perros , Proteínas Fluorescentes Verdes/química , Glicoproteínas de Membrana/química , Proteínas de la Membrana/metabolismo , Microscopía Confocal/métodos , Microscopía Electrónica de Transmisión/métodos , Fosfoproteínas/metabolismo , Estructura Terciaria de Proteína , ARN Interferente Pequeño/metabolismo , Transfección , Proteína de la Zonula Occludens-1
19.
Proc Natl Acad Sci U S A ; 106(5): 1392-7, 2009 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-19171884

RESUMEN

Recent studies suggest that superoxide dismutase 1 (SOD1)-linked amyotrophic lateral sclerosis results from destabilization and misfolding of mutant forms of this abundant cytosolic enzyme. Here, we have tracked the expression and fate of a misfolding-prone human SOD1, G85R, fused to YFP, in a line of transgenic G85R SOD1-YFP mice. These mice, but not wild-type human SOD1-YFP transgenics, developed lethal paralyzing motor symptoms at 9 months. In situ RNA hybridization of spinal cords revealed predominant expression in motor neurons in spinal cord gray matter in all transgenic animals. Concordantly, G85R SOD-YFP was diffusely fluorescent in motor neurons of animals at 1 and 6 months of age, but at the time of symptoms, punctate aggregates were observed in cell bodies and processes. Biochemical analyses of spinal cord soluble extracts indicated that G85R SOD-YFP behaved as a misfolded monomer at all ages. It became progressively insoluble at 6 and 9 months of age, associated with presence of soluble oligomers observable by gel filtration. Immunoaffinity capture and mass spectrometry revealed association of G85R SOD-YFP, but not WT SOD-YFP, with the cytosolic chaperone Hsc70 at all ages. In addition, 3 Hsp110's, nucleotide exchange factors for Hsp70s, were captured at 6 and 9 months. Despite such chaperone interactions, G85R SOD-YFP formed insoluble inclusions at late times, containing predominantly intermediate filament proteins. We conclude that motor neurons, initially "compensated" to maintain the misfolded protein in a soluble state, become progressively unable to do so.


Asunto(s)
Esclerosis Amiotrófica Lateral/genética , Proteínas Luminiscentes/genética , Chaperonas Moleculares/metabolismo , Superóxido Dismutasa/genética , Animales , Proteína Ácida Fibrilar de la Glía/metabolismo , Ratones , Ratones Transgénicos , Neuronas Motoras/metabolismo , Hibridación de Ácido Nucleico , Solubilidad , Médula Espinal/citología , Médula Espinal/metabolismo , Ubiquitina/metabolismo
20.
J Crohns Colitis ; 16(12): 1874-1881, 2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-35868223

RESUMEN

BACKGROUND: Patient-reported outcome measures [PROMs] are key to documenting outcomes that matter most to patients and are increasingly important to commissioners of health care seeking value. We report the first series of the ICHOM Standard Set for Inflammatory Bowel Disease [IBD]. METHODS: Patients treated for ulcerative colitis [UC] or Crohn's disease [CD] in our centre were offered enrolment into the web-based TrueColours-IBD programme. Through this programme, e-mail prompts linking to validated questionnaires were sent for symptoms, quality of life, and ICHOM IBD outcomes. RESULTS: The first 1299 consecutive patients enrolled [779 UC, 520 CD] were studied with median 270 days of follow-up (interquartile range [IQR] 116, 504). 671 [52%] were female, mean age 42 years (standard deviation [sd] 16), mean body mass index [BMI] 26 [sd 5.3]. At registration, 483 [37%] were using advanced therapies. Median adherence to fortnightly quality of life reporting and quarterly outcomes was 100% [IQR 48, 100%] and 100% [IQR 75, 100%], respectively. In the previous 12 months, prednisolone use was reported by 229 [29%] patients with UC vs 81 [16%] with CD, p <0.001; 202 [16%] for <3 months; and 108 [8%] for >3 months. An IBD-related intervention was reported by 174 [13%] patients, and 80 [6%] reported an unplanned hospital admission. There were high rates of fatigue [50%] and mood disturbance [23%]. CONCLUSIONS: Outcomes reported by patients illustrate the scale of the therapeutic deficit in current care. Proof of principle is demonstrated that PROM data can be collected continuously with little burden on health care professionals. This may become a metric for quality improvement programmes or to compare outcomes.


Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Humanos , Femenino , Adulto , Masculino , Calidad de Vida , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/tratamiento farmacológico , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/terapia , Medición de Resultados Informados por el Paciente , Enfermedad Crónica
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