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1.
Cell ; 185(11): 1974-1985.e12, 2022 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-35512704

RESUMO

Comprehensive sequencing of patient tumors reveals genomic mutations across tumor types that enable tumorigenesis and progression. A subset of oncogenic driver mutations results in neomorphic activity where the mutant protein mediates functions not engaged by the parental molecule. Here, we identify prevalent variant-enabled neomorph-protein-protein interactions (neoPPI) with a quantitative high-throughput differential screening (qHT-dS) platform. The coupling of highly sensitive BRET biosensors with miniaturized coexpression in an ultra-HTS format allows large-scale monitoring of the interactions of wild-type and mutant variant counterparts with a library of cancer-associated proteins in live cells. The screening of 17,792 interactions with 2,172,864 data points revealed a landscape of gain of interactions encompassing both oncogenic and tumor suppressor mutations. For example, the recurrent BRAF V600E lesion mediates KEAP1 neoPPI, rewiring a BRAFV600E/KEAP1 signaling axis and creating collateral vulnerability to NQO1 substrates, offering a combination therapeutic strategy. Thus, cancer genomic alterations can create neo-interactions, informing variant-directed therapeutic approaches for precision medicine.


Assuntos
Neoplasias , Proteínas Proto-Oncogênicas B-raf , Carcinogênese , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Mutação , Fator 2 Relacionado a NF-E2/metabolismo , Neoplasias/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo
2.
Cell ; 185(12): 2184-2199.e16, 2022 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-35649412

RESUMO

The factors driving therapy resistance in diffuse glioma remain poorly understood. To identify treatment-associated cellular and genetic changes, we analyzed RNA and/or DNA sequencing data from the temporally separated tumor pairs of 304 adult patients with isocitrate dehydrogenase (IDH)-wild-type and IDH-mutant glioma. Tumors recurred in distinct manners that were dependent on IDH mutation status and attributable to changes in histological feature composition, somatic alterations, and microenvironment interactions. Hypermutation and acquired CDKN2A deletions were associated with an increase in proliferating neoplastic cells at recurrence in both glioma subtypes, reflecting active tumor growth. IDH-wild-type tumors were more invasive at recurrence, and their neoplastic cells exhibited increased expression of neuronal signaling programs that reflected a possible role for neuronal interactions in promoting glioma progression. Mesenchymal transition was associated with the presence of a myeloid cell state defined by specific ligand-receptor interactions with neoplastic cells. Collectively, these recurrence-associated phenotypes represent potential targets to alter disease progression.


Assuntos
Neoplasias Encefálicas , Glioma , Microambiente Tumoral , Adulto , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Evolução Molecular , Genes p16 , Glioma/genética , Glioma/patologia , Humanos , Isocitrato Desidrogenase/genética , Mutação , Recidiva Local de Neoplasia
3.
Cell ; 178(6): 1493-1508.e20, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31474370

RESUMO

Clinical benefits of cytokine blockade in ileal Crohn's disease (iCD) are limited to a subset of patients. Here, we applied single-cell technologies to iCD lesions to address whether cellular heterogeneity contributes to treatment resistance. We found that a subset of patients expressed a unique cellular module in inflamed tissues that consisted of IgG plasma cells, inflammatory mononuclear phagocytes, activated T cells, and stromal cells, which we named the GIMATS module. Analysis of ligand-receptor interaction pairs identified a distinct network connectivity that likely drives the GIMATS module. Strikingly, the GIMATS module was also present in a subset of patients in four independent iCD cohorts (n = 441), and its presence at diagnosis correlated with failure to achieve durable corticosteroid-free remission upon anti-TNF therapy. These results emphasize the limitations of current diagnostic assays and the potential for single-cell mapping tools to identify novel biomarkers of treatment response and tailored therapeutic opportunities.


Assuntos
Doença de Crohn/terapia , Citocinas/imunologia , Intestinos/patologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Doença de Crohn/imunologia , Doença de Crohn/patologia , Humanos , Imunoterapia/métodos , Fagócitos/patologia , Análise de Célula Única , Células Estromais/patologia , Linfócitos T/patologia
4.
Immunity ; 57(2): 319-332.e6, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38295798

RESUMO

Tuft cells in mucosal tissues are key regulators of type 2 immunity. Here, we examined the impact of the microbiota on tuft cell biology in the intestine. Succinate induction of tuft cells and type 2 innate lymphoid cells was elevated with loss of gut microbiota. Colonization with butyrate-producing bacteria or treatment with butyrate suppressed this effect and reduced intestinal histone deacetylase activity. Epithelial-intrinsic deletion of the epigenetic-modifying enzyme histone deacetylase 3 (HDAC3) inhibited tuft cell expansion in vivo and impaired type 2 immune responses during helminth infection. Butyrate restricted stem cell differentiation into tuft cells, and inhibition of HDAC3 in adult mice and human intestinal organoids blocked tuft cell expansion. Collectively, these data define a HDAC3 mechanism in stem cells for tuft cell differentiation that is dampened by a commensal metabolite, revealing a pathway whereby the microbiota calibrate intestinal type 2 immunity.


Assuntos
Mucosa Intestinal , Microbiota , Adulto , Camundongos , Humanos , Animais , Células em Tufo , Butiratos/farmacologia , Butiratos/metabolismo , Imunidade Inata , Linfócitos/metabolismo , Intestinos , Histona Desacetilases/metabolismo , Diferenciação Celular
5.
Cell ; 164(3): 526-37, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26824660

RESUMO

The basal ganglia (BG) are critical for adaptive motor control, but the circuit principles underlying their pathway-specific modulation of target regions are not well understood. Here, we dissect the mechanisms underlying BG direct and indirect pathway-mediated control of the mesencephalic locomotor region (MLR), a brainstem target of BG that is critical for locomotion. We optogenetically dissect the locomotor function of the three neurochemically distinct cell types within the MLR: glutamatergic, GABAergic, and cholinergic neurons. We find that the glutamatergic subpopulation encodes locomotor state and speed, is necessary and sufficient for locomotion, and is selectively innervated by BG. We further show activation and suppression, respectively, of MLR glutamatergic neurons by direct and indirect pathways, which is required for bidirectional control of locomotion by BG circuits. These findings provide a fundamental understanding of how BG can initiate or suppress a motor program through cell-type-specific regulation of neurons linked to specific actions.


Assuntos
Gânglios da Base/fisiologia , Mapeamento Encefálico , Mesencéfalo/citologia , Atividade Motora , Vias Neurais , Animais , Neurônios GABAérgicos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/fisiologia , Optogenética
6.
Mol Cell ; 82(1): 15-29, 2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-34813758

RESUMO

Deubiquitinases (DUBs) are specialized proteases that remove ubiquitin from substrates or cleave within ubiquitin chains to regulate ubiquitylation and therefore play important roles in eukaryotic biology. Dysregulation of DUBs is implicated in several human diseases, highlighting the importance of DUB function. In addition, many pathogenic bacteria and viruses encode and deploy DUBs to manipulate host immune responses and establish infectious diseases in humans and animals. Hence, therapeutic targeting of DUBs is an increasingly explored area that requires an in-depth mechanistic understanding of human and pathogenic DUBs. In this review, we summarize the multiple layers of regulation that control autoinhibition, activation, and substrate specificity of DUBs. We discuss different strategies to inhibit DUBs and the progress in developing selective small-molecule DUB inhibitors. Finally, we propose a classification system of DUB inhibitors based on their mode of action.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Enzimas Desubiquitinantes , Inibidores Enzimáticos/uso terapêutico , SARS-CoV-2 , Ubiquitinação/efeitos dos fármacos , COVID-19/enzimologia , Enzimas Desubiquitinantes/antagonistas & inibidores , Enzimas Desubiquitinantes/metabolismo , Humanos
7.
Mol Cell ; 81(20): 4176-4190.e6, 2021 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-34529927

RESUMO

Of the eight distinct polyubiquitin (polyUb) linkages that can be assembled, the roles of K48-linked polyUb (K48-polyUb) are the most established, with K48-polyUb modified proteins being targeted for degradation. MINDY1 and MINDY2 are members of the MINDY family of deubiquitinases (DUBs) that have exquisite specificity for cleaving K48-polyUb, yet we have a poor understanding of their catalytic mechanism. Here, we analyze the crystal structures of MINDY1 and MINDY2 alone and in complex with monoUb, di-, and penta-K48-polyUb, identifying 5 distinct Ub binding sites in the catalytic domain that explain how these DUBs sense both Ub chain length and linkage type to cleave K48-polyUb chains. The activity of MINDY1/2 is inhibited by the Cys-loop, and we find that substrate interaction relieves autoinhibition to activate these DUBs. We also find that MINDY1/2 use a non-canonical catalytic triad composed of Cys-His-Thr. Our findings highlight multiple layers of regulation modulating DUB activity in MINDY1 and MINDY2.


Assuntos
Enzimas Desubiquitinantes/metabolismo , Poliubiquitina/metabolismo , Ubiquitina Tiolesterase/metabolismo , Sítios de Ligação , Domínio Catalítico , Cristalografia , Enzimas Desubiquitinantes/genética , Ativação Enzimática , Humanos , Cinética , Modelos Moleculares , Mutação , Ligação Proteica , Conformação Proteica , Espalhamento a Baixo Ângulo , Relação Estrutura-Atividade , Ubiquitina Tiolesterase/genética , Ubiquitinação
8.
Nat Immunol ; 17(5): 538-44, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27043413

RESUMO

Acidic mammalian chitinase (AMCase) is known to be induced by allergens and helminths, yet its role in immunity is unclear. Using AMCase-deficient mice, we show that AMCase deficiency reduced the number of group 2 innate lymphoid cells during allergen challenge but was not required for establishment of type 2 inflammation in the lung in response to allergens or helminths. In contrast, AMCase-deficient mice showed a profound defect in type 2 immunity following infection with the chitin-containing gastrointestinal nematodes Nippostrongylus brasiliensis and Heligmosomoides polygyrus bakeri. The impaired immunity was associated with reduced mucus production and decreased intestinal expression of the signature type 2 response genes Il13, Chil3, Retnlb, and Clca1. CD103(+) dendritic cells, which regulate T cell homing, were also reduced in mesenteric lymph nodes of infected AMCase-deficient mice. Thus, AMCase functions as a critical initiator of protective type 2 responses to intestinal nematodes but is largely dispensable for allergic responses in the lung.


Assuntos
Quitinases/imunologia , Trato Gastrointestinal/imunologia , Imunidade/imunologia , Infecções por Strongylida/imunologia , Animais , Quitinases/genética , Quitinases/metabolismo , Canais de Cloreto/genética , Canais de Cloreto/imunologia , Canais de Cloreto/metabolismo , Citometria de Fluxo , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/parasitologia , Expressão Gênica/imunologia , Hormônios Ectópicos/genética , Hormônios Ectópicos/imunologia , Hormônios Ectópicos/metabolismo , Interações Hospedeiro-Parasita/imunologia , Hipersensibilidade/genética , Hipersensibilidade/imunologia , Hipersensibilidade/metabolismo , Imunidade/genética , Peptídeos e Proteínas de Sinalização Intercelular , Interleucina-13/genética , Interleucina-13/imunologia , Interleucina-13/metabolismo , Lectinas/genética , Lectinas/imunologia , Lectinas/metabolismo , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia de Fluorescência , Nematospiroides dubius/imunologia , Nematospiroides dubius/fisiologia , Nippostrongylus/imunologia , Nippostrongylus/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Infecções por Strongylida/metabolismo , Infecções por Strongylida/parasitologia , beta-N-Acetil-Hexosaminidases/genética , beta-N-Acetil-Hexosaminidases/imunologia , beta-N-Acetil-Hexosaminidases/metabolismo
9.
Proc Natl Acad Sci U S A ; 121(3): e2317228120, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38190523

RESUMO

As bees' main source of protein and lipids, pollen is critical for their development, reproduction, and health. Plant species vary considerably in the macronutrient content of their pollen, and research in bee model systems has established that this variation both modulates performance and guides floral choice. Yet, how variation in pollen chemistry shapes interactions between plants and bees in natural communities is an open question, essential for both understanding the nutritional dynamics of plant-pollinator mutualisms and informing their conservation. To fill this gap, we asked how pollen nutrition (relative protein and lipid content) sampled from 109 co-flowering plant species structured visitation patterns observed among 75 subgenera of pollen-collecting bees in the Great Basin/Eastern Sierra region (USA). We found that the degree of similarity in co-flowering plant species' pollen nutrition predicted similarity among their visitor communities, even after accounting for floral morphology and phylogeny. Consideration of pollen nutrition also shed light on the structure of this interaction network: Bee subgenera and plant genera were arranged into distinct, interconnected groups, delineated by differences in pollen macronutrient values, revealing potential nutritional niches. Importantly, variation in pollen nutrition alone (high in protein, high in lipid, or balanced) did not predict the diversity of bee visitors, indicating that plant species offering complementary pollen nutrition may be equally valuable in supporting bee diversity. Nutritional diversity should thus be a key consideration when selecting plants for habitat restoration, and a nutritionally explicit perspective is needed when considering reward systems involved in the community ecology of pollination.


Assuntos
Magnoliopsida , Pólen , Abelhas , Animais , Estado Nutricional , Nutrientes , Comportamento Compulsivo , Lipídeos
10.
Nature ; 586(7827): 108-112, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32731255

RESUMO

The coevolution of mammalian hosts and their beneficial commensal microbes has led to development of symbiotic host-microbiota relationships1. Epigenetic machinery permits mammalian cells to integrate environmental signals2; however, how these pathways are fine-tuned by diverse cues from commensal bacteria is not well understood. Here we reveal a highly selective pathway through which microbiota-derived inositol phosphate regulates histone deacetylase 3 (HDAC3) activity in the intestine. Despite the abundant presence of HDAC inhibitors such as butyrate in the intestine, we found that HDAC3 activity was sharply increased in intestinal epithelial cells of microbiota-replete mice compared with germ-free mice. This divergence was reconciled by the finding that commensal bacteria, including Escherichia coli, stimulated HDAC activity through metabolism of phytate and production of inositol-1,4,5-trisphosphate (InsP3). Both intestinal exposure to InsP3 and phytate ingestion promoted recovery following intestinal damage. Of note, InsP3 also induced growth of intestinal organoids derived from human tissue, stimulated HDAC3-dependent proliferation and countered butyrate inhibition of colonic growth. Collectively, these results show that InsP3 is a microbiota-derived metabolite that activates a mammalian histone deacetylase to promote epithelial repair. Thus, HDAC3 represents a convergent epigenetic sensor of distinct metabolites that calibrates host responses to diverse microbial signals.


Assuntos
Microbioma Gastrointestinal/fisiologia , Histona Desacetilases/metabolismo , Inositol 1,4,5-Trifosfato/metabolismo , Intestinos/enzimologia , Intestinos/microbiologia , Ácido Fítico/metabolismo , Animais , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/enzimologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Intestinos/citologia , Intestinos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Organoides/enzimologia , Organoides/metabolismo , Organoides/patologia , Simbiose
11.
Nature ; 580(7804): 517-523, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32322066

RESUMO

A high tumour mutational burden (hypermutation) is observed in some gliomas1-5; however, the mechanisms by which hypermutation develops and whether it predicts the response to immunotherapy are poorly understood. Here we comprehensively analyse the molecular determinants of mutational burden and signatures in 10,294 gliomas. We delineate two main pathways to hypermutation: a de novo pathway associated with constitutional defects in DNA polymerase and mismatch repair (MMR) genes, and a more common post-treatment pathway, associated with acquired resistance driven by MMR defects in chemotherapy-sensitive gliomas that recur after treatment with the chemotherapy drug temozolomide. Experimentally, the mutational signature of post-treatment hypermutated gliomas was recapitulated by temozolomide-induced damage in cells with MMR deficiency. MMR-deficient gliomas were characterized by a lack of prominent T cell infiltrates, extensive intratumoral heterogeneity, poor patient survival and a low rate of response to PD-1 blockade. Moreover, although bulk analyses did not detect microsatellite instability in MMR-deficient gliomas, single-cell whole-genome sequencing analysis of post-treatment hypermutated glioma cells identified microsatellite mutations. These results show that chemotherapy can drive the acquisition of hypermutated populations without promoting a response to PD-1 blockade and supports the diagnostic use of mutational burden and signatures in cancer.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Glioma/genética , Glioma/terapia , Mutação , Animais , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/imunologia , Reparo de Erro de Pareamento de DNA/genética , Frequência do Gene , Genoma Humano/efeitos dos fármacos , Genoma Humano/genética , Glioma/imunologia , Humanos , Masculino , Camundongos , Repetições de Microssatélites/efeitos dos fármacos , Repetições de Microssatélites/genética , Mutagênese/efeitos dos fármacos , Mutação/efeitos dos fármacos , Fenótipo , Prognóstico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Análise de Sequência de DNA , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Proc Natl Acad Sci U S A ; 120(33): e2304415120, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37549296

RESUMO

Real-world healthcare data sharing is instrumental in constructing broader-based and larger clinical datasets that may improve clinical decision-making research and outcomes. Stakeholders are frequently reluctant to share their data without guaranteed patient privacy, proper protection of their datasets, and control over the usage of their data. Fully homomorphic encryption (FHE) is a cryptographic capability that can address these issues by enabling computation on encrypted data without intermediate decryptions, so the analytics results are obtained without revealing the raw data. This work presents a toolset for collaborative privacy-preserving analysis of oncological data using multiparty FHE. Our toolset supports survival analysis, logistic regression training, and several common descriptive statistics. We demonstrate using oncological datasets that the toolset achieves high accuracy and practical performance, which scales well to larger datasets. As part of this work, we propose a cryptographic protocol for interactive bootstrapping in multiparty FHE, which is of independent interest. The toolset we develop is general-purpose and can be applied to other collaborative medical and healthcare application domains.


Assuntos
Segurança Computacional , Privacidade , Humanos , Modelos Logísticos , Tomada de Decisão Clínica
13.
Proc Natl Acad Sci U S A ; 120(19): e2220911120, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37126681

RESUMO

Narcolepsy with cataplexy is a sleep disorder caused by deficiency in the hypothalamic neuropeptide hypocretin/orexin (HCRT), unanimously believed to result from autoimmune destruction of hypocretin-producing neurons. HCRT deficiency can also occur in secondary forms of narcolepsy and be only temporary, suggesting it can occur without irreversible neuronal loss. The recent discovery that narcolepsy patients also show loss of hypothalamic (corticotropin-releasing hormone) CRH-producing neurons suggests that other mechanisms than cell-specific autoimmune attack, are involved. Here, we identify the HCRT cell-colocalized neuropeptide QRFP as the best marker of HCRT neurons. We show that if HCRT neurons are ablated in mice, in addition to Hcrt, Qrfp transcript is also lost in the lateral hypothalamus, while in mice where only the Hcrt gene is inactivated Qrfp is unchanged. Similarly, postmortem hypothalamic tissues of narcolepsy patients show preserved QRFP expression, suggesting the neurons are present but fail to actively produce HCRT. We show that the promoter of the HCRT gene of patients exhibits hypermethylation at a methylation-sensitive and evolutionary-conserved PAX5:ETS1 transcription factor-binding site, suggesting the gene is subject to transcriptional silencing. We show also that in addition to HCRT, CRH and Dynorphin (PDYN) gene promoters, exhibit hypermethylation in the hypothalamus of patients. Altogether, we propose that HCRT, PDYN, and CRH are epigenetically silenced by a hypothalamic assault (inflammation) in narcolepsy patients, without concurrent cell death. Since methylation is reversible, our findings open the prospect of reversing or curing narcolepsy.


Assuntos
Cataplexia , Narcolepsia , Neuropeptídeos , Camundongos , Animais , Orexinas/metabolismo , Cataplexia/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neuropeptídeos/metabolismo , Narcolepsia/genética , Hipotálamo/metabolismo , Epigênese Genética , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/metabolismo
14.
J Biol Chem ; 300(6): 107300, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38641066

RESUMO

Integrin-mediated activation of the profibrotic mediator transforming growth factor-ß1 (TGF-ß1), plays a critical role in idiopathic pulmonary fibrosis (IPF) pathogenesis. Galectin-3 is believed to contribute to the pathological wound healing seen in IPF, although its mechanism of action is not precisely defined. We hypothesized that galectin-3 potentiates TGF-ß1 activation and/or signaling in the lung to promote fibrogenesis. We show that galectin-3 induces TGF-ß1 activation in human lung fibroblasts (HLFs) and specifically that extracellular galectin-3 promotes oleoyl-L-α-lysophosphatidic acid sodium salt-induced integrin-mediated TGF-ß1 activation. Surface plasmon resonance analysis confirmed that galectin-3 binds to αv integrins, αvß1, αvß5, and αvß6, and to the TGFßRII subunit in a glycosylation-dependent manner. This binding is heterogeneous and not a 1:1 binding stoichiometry. Binding interactions were blocked by small molecule inhibitors of galectin-3, which target the carbohydrate recognition domain. Galectin-3 binding to ß1 integrin was validated in vitro by coimmunoprecipitation in HLFs. Proximity ligation assays indicated that galectin-3 and ß1 integrin colocalize closely (≤40 nm) on the cell surface and that colocalization is increased by TGF-ß1 treatment and blocked by galectin-3 inhibitors. In the absence of TGF-ß1 stimulation, colocalization was detectable only in HLFs from IPF patients, suggesting the proteins are inherently more closely associated in the disease state. Galectin-3 inhibitor treatment of precision cut lung slices from IPF patients' reduced Col1a1, TIMP1, and hyaluronan secretion to a similar degree as TGF-ß type I receptor inhibitor. These data suggest that galectin-3 promotes TGF-ß1 signaling and may induce fibrogenesis by interacting directly with components of the TGF-ß1 signaling cascade.


Assuntos
Fibroblastos , Galectina 3 , Fibrose Pulmonar Idiopática , Fator de Crescimento Transformador beta1 , Humanos , Fator de Crescimento Transformador beta1/metabolismo , Galectina 3/metabolismo , Galectina 3/genética , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose Pulmonar Idiopática/metabolismo , Fibrose Pulmonar Idiopática/patologia , Pulmão/metabolismo , Pulmão/patologia , Transdução de Sinais , Receptor do Fator de Crescimento Transformador beta Tipo II/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Galectinas/metabolismo , Colágeno Tipo I/metabolismo , Células Cultivadas , Proteínas Sanguíneas
15.
Gastroenterology ; 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39173722

RESUMO

BACKGROUND & AIMS: Inflammatory bowel disease (IBD) is a chronic manifestation of dysregulated immune response to the gut microbiota in genetically predisposed hosts. Nearly half of patients with Crohn's disease (CD) develop selective serum immunoglobulin (Ig)G response to flagellin proteins expressed by bacteria in the Lachnospiraceae family. This study aimed to identify the binding epitopes of these IgG antibodies and assess their relevance in CD and in homeostasis. METHODS: Sera from an adult CD cohort, a treatment-naïve pediatric CD cohort, and 3 independent non-IBD infant cohorts were analyzed using novel techniques including a flagellin peptide microarray and a flagellin peptide cytometric bead array. RESULTS: A dominant B cell peptide epitope in patients with CD was identified, located in the highly conserved "hinge region" between the D0 and D1 domains at the amino-terminus of Lachnospiraceae flagellins. Elevated serum IgG reactivity to the hinge peptide was strongly associated with incidence of CD and the development of disease complications in children with CD up to 5 years in advance. Notably, high levels of serum IgG to the hinge epitope were also found in most infants from 3 different geographic regions (Uganda, Sweden, and the United States) at 1 year of age, which decrements rapidly afterward. CONCLUSIONS: These findings identified a distinct subset of patients with CD, united by a shared reactivity to a dominant commensal bacterial flagellin epitope, that may represent failure of a homeostatic response to the gut microbiota beginning in infancy.

16.
Development ; 149(17)2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35950911

RESUMO

Coordinated migration of the mesoderm is essential for accurate organization of the body plan during embryogenesis. However, little is known about how mesoderm migration influences posterior neural tube closure in mammals. Here, we show that spinal neural tube closure and lateral migration of the caudal paraxial mesoderm depend on transmembrane protein 132A (TMEM132A), a single-pass type I transmembrane protein, the function of which is not fully understood. Our study in Tmem132a-null mice and cell models demonstrates that TMEM132A regulates several integrins and downstream integrin pathway activation as well as cell migration behaviors. Our data also implicates mesoderm migration in elevation of the caudal neural folds and successful closure of the caudal neural tube. These results suggest a requirement for paraxial mesodermal cell migration during spinal neural tube closure, disruption of which may lead to spina bifida.


Assuntos
Proteínas de Membrana , Defeitos do Tubo Neural , Tubo Neural , Animais , Integrinas/metabolismo , Proteínas de Membrana/genética , Mesoderma/metabolismo , Camundongos , Camundongos Knockout , Tubo Neural/metabolismo , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/metabolismo
17.
Nature ; 569(7758): 655-662, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31142855

RESUMO

Inflammatory bowel diseases, which include Crohn's disease and ulcerative colitis, affect several million individuals worldwide. Crohn's disease and ulcerative colitis are complex diseases that are heterogeneous at the clinical, immunological, molecular, genetic, and microbial levels. Individual contributing factors have been the focus of extensive research. As part of the Integrative Human Microbiome Project (HMP2 or iHMP), we followed 132 subjects for one year each to generate integrated longitudinal molecular profiles of host and microbial activity during disease (up to 24 time points each; in total 2,965 stool, biopsy, and blood specimens). Here we present the results, which provide a comprehensive view of functional dysbiosis in the gut microbiome during inflammatory bowel disease activity. We demonstrate a characteristic increase in facultative anaerobes at the expense of obligate anaerobes, as well as molecular disruptions in microbial transcription (for example, among clostridia), metabolite pools (acylcarnitines, bile acids, and short-chain fatty acids), and levels of antibodies in host serum. Periods of disease activity were also marked by increases in temporal variability, with characteristic taxonomic, functional, and biochemical shifts. Finally, integrative analysis identified microbial, biochemical, and host factors central to this dysregulation. The study's infrastructure resources, results, and data, which are available through the Inflammatory Bowel Disease Multi'omics Database ( http://ibdmdb.org ), provide the most comprehensive description to date of host and microbial activities in inflammatory bowel diseases.


Assuntos
Microbioma Gastrointestinal/genética , Doenças Inflamatórias Intestinais/microbiologia , Animais , Fungos/patogenicidade , Microbioma Gastrointestinal/imunologia , Saúde , Humanos , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/terapia , Doenças Inflamatórias Intestinais/virologia , Filogenia , Especificidade da Espécie , Transcriptoma , Vírus/patogenicidade
18.
Biophys J ; 123(13): 1781-1791, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38783603

RESUMO

Controlling the reduction midpoint potential of heme B is a key factor in many bioelectrochemical reactions, including long-range electron transport. Currently, there are a number of globular model protein systems to study this biophysical parameter; however, there are none for large polymeric protein model systems (e.g., the OmcS protein from G. sulfurreducens). Peptide amphiphiles, short peptides with a lipid tail that polymerize into fibrous structures, fill this gap. Here, we show a peptide amphiphile model system where one can tune the electrochemical potential of heme B by changing the loading ratio and peptide sequence. Changing the loading ratio resulted in the most significant increase, with values as high as -22 mV down to -224 mV. Circular dichroism spectra of certain sequences show Cotton effects at lower loading ratios that disappear as more heme B is added, indicating an ordered environment that becomes disrupted if heme B is overpacked. These findings can contribute to the design of functional self-assembling biomaterials.


Assuntos
Heme , Oxirredução , Peptídeos , Heme/química , Peptídeos/química , Sequência de Aminoácidos , Tensoativos/química
19.
J Neurophysiol ; 132(3): 791-807, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39081213

RESUMO

Neurostimulation/neurorecording are tools to study, diagnose, and treat neurological/psychiatric conditions. Both techniques depend on volume conduction between scalp and excitable brain tissue. Here, we examine how neurostimulation with transcranial magnetic stimulation (TMS) is affected by hydration status, a physiological variable that can influence the volume of fluid spaces/cells, excitability, and cellular/global brain functioning. Normal healthy adult participants (32, 9 males) had common motor TMS measures taken in a repeated-measures design from dehydrated (12-h overnight fast/thirst) and rehydrated (identical dehydration protocol followed by rehydration with 1 L water in 1 h) testing days. The target region was left primary motor cortex hand area. Response at the target muscle was recorded with electromyography. Urinalysis confirmed hydration status. Motor hotspot shifted in half of participants. Motor threshold decreased in rehydration, indicating increased excitability. Even after redosing/relocalizing TMS to the new threshold/hotspot, rehydration still showed evidence of increased excitability: recruitment curve measures generally shifted upward and the glutamate-dependent paired-pulse protocol, short intracortical facilitation (SICF), was increased. Short intracortical inhibition (SICI), long intracortical inhibition (LICI), long intracortical facilitation (LICF), and cortical silent period (CSP) were relatively unaffected. The hydration perturbations were mild/subclinical based on the magnitude/speed and urinalysis. Motor TMS measures showed evidence of expected physiological changes of osmotic challenges. Rehydration showed signs of macroscopic and microscopic volume changes including decreased scalp-cortex distance (brain closer to stimulator) and astrocyte swelling-induced glutamate release. Hydration may be a source of variability affecting any techniques dependent on brain volumes/volume conduction. These concepts are important for researchers/clinicians using such techniques or dealing with the wide variety of disease processes involving water balance.NEW & NOTEWORTHY Hydration status can affect brain volumes and excitability, which should affect techniques dependent on electrical volume conduction, including neurostimulation/recording. We test the previously unknown effects of hydration on neurostimulation with TMS and briefly review relevant physiology of hydration. Rehydration showed lower motor threshold, shifted motor hotspot, and generally larger responses even after compensating for threshold/hotspot changes. This is important for clinical and research applications of neurostimulation/neurorecording and the many clinical disorders related to water balance.


Assuntos
Desidratação , Potencial Evocado Motor , Córtex Motor , Estimulação Magnética Transcraniana , Humanos , Masculino , Adulto , Feminino , Córtex Motor/fisiologia , Potencial Evocado Motor/fisiologia , Desidratação/fisiopatologia , Adulto Jovem , Estado de Hidratação do Organismo/fisiologia , Eletromiografia
20.
Mol Biol Evol ; 40(3)2023 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-36814414

RESUMO

Genetic divergence is the fundamental process that drives evolution and ultimately speciation. Structural variants (SVs) are large-scale genomic differences within a species or population and can cause functionally important phenotypic differences. Characterizing SVs across invasive species will fill knowledge gaps regarding how patterns of genetic diversity and genetic architecture shape rapid adaptation under new selection regimes. Here, we seek to understand patterns in genetic diversity within the globally invasive European starling, Sturnus vulgaris. Using whole genome sequencing of eight native United Kingdom (UK), eight invasive North America (NA), and 33 invasive Australian (AU) starlings, we examine patterns in genome-wide SNPs and SVs between populations and within Australia. Our findings detail the landscape of standing genetic variation across recently diverged continental populations of this invasive avian. We demonstrate that patterns of genetic diversity estimated from SVs do not necessarily reflect relative patterns from SNP data, either when considering patterns of diversity along the length of the organism's chromosomes (owing to enrichment of SVs in subtelomeric repeat regions), or interpopulation diversity patterns (possibly a result of altered selection regimes or introduction history). Finally, we find that levels of balancing selection within the native range differ across SNP and SV of different classes and outlier classifications. Overall, our results demonstrate that the processes that shape allelic diversity within populations is complex and support the need for further investigation of SVs across a range of taxa to better understand correlations between often well-studied SNP diversity and that of SVs.


Assuntos
Genômica , Polimorfismo de Nucleotídeo Único , Austrália , Sequenciamento Completo do Genoma , Adaptação Fisiológica , Variação Genética
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