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1.
Nat Chem Biol ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965384

RESUMO

Targeted protein degradation (TPD) is an emerging therapeutic strategy that would benefit from new chemical entities with which to recruit a wider variety of ubiquitin E3 ligases to target proteins for proteasomal degradation. Here we describe a TPD strategy involving the recruitment of FBXO22 to induce degradation of the histone methyltransferase and oncogene NSD2. UNC8732 facilitates FBXO22-mediated degradation of NSD2 in acute lymphoblastic leukemia cells harboring the NSD2 gain-of-function mutation p.E1099K, resulting in growth suppression, apoptosis and reversal of drug resistance. The primary amine of UNC8732 is metabolized to an aldehyde species, which engages C326 of FBXO22 to recruit the SCFFBXO22 Cullin complex. We further demonstrate that a previously reported alkyl amine-containing degrader targeting XIAP is similarly dependent on SCFFBXO22. Overall, we present a potent NSD2 degrader for the exploration of NSD2 disease phenotypes and a new FBXO22-recruitment strategy for TPD.

2.
Nat Chem Biol ; 19(5): 624-632, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36797403

RESUMO

The nucleosome acidic patch is a major interaction hub for chromatin, providing a platform for enzymes to dock and orient for nucleosome-targeted activities. To define the molecular basis of acidic patch recognition proteome wide, we performed an amino acid resolution acidic patch interactome screen. We discovered that the histone H3 lysine 36 (H3K36) demethylase KDM2A, but not its closely related paralog, KDM2B, requires the acidic patch for nucleosome binding. Despite fundamental roles in transcriptional repression in health and disease, the molecular mechanisms governing nucleosome substrate specificity of KDM2A/B, or any related JumonjiC (JmjC) domain lysine demethylase, remain unclear. We used a covalent conjugate between H3K36 and a demethylase inhibitor to solve cryogenic electron microscopy structures of KDM2A and KDM2B trapped in action on a nucleosome substrate. Our structures show that KDM2-nucleosome binding is paralog specific and facilitated by dynamic nucleosomal DNA unwrapping and histone charge shielding that mobilize the H3K36 sequence for demethylation.


Assuntos
Lisina , Nucleossomos , Histonas/metabolismo , Cromatina , Histona Desmetilases com o Domínio Jumonji/química
3.
Nat Chem Biol ; 18(1): 56-63, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34782742

RESUMO

Nuclear receptor-binding SET domain-containing 2 (NSD2) is the primary enzyme responsible for the dimethylation of lysine 36 of histone 3 (H3K36), a mark associated with active gene transcription and intergenic DNA methylation. In addition to a methyltransferase domain, NSD2 harbors two proline-tryptophan-tryptophan-proline (PWWP) domains and five plant homeodomains (PHDs) believed to serve as chromatin reading modules. Here, we report a chemical probe targeting the N-terminal PWWP (PWWP1) domain of NSD2. UNC6934 occupies the canonical H3K36me2-binding pocket of PWWP1, antagonizes PWWP1 interaction with nucleosomal H3K36me2 and selectively engages endogenous NSD2 in cells. UNC6934 induces accumulation of endogenous NSD2 in the nucleolus, phenocopying the localization defects of NSD2 protein isoforms lacking PWWP1 that result from translocations prevalent in multiple myeloma (MM). Mutations of other NSD2 chromatin reader domains also increase NSD2 nucleolar localization and enhance the effect of UNC6934. This chemical probe and the accompanying negative control UNC7145 will be useful tools in defining NSD2 biology.


Assuntos
Nucléolo Celular/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Sondas Moleculares/química , Domínios Proteicos , Proteínas Repressoras/metabolismo , Metilação , Mieloma Múltiplo/metabolismo , Nucleossomos/metabolismo
4.
Cell Mol Life Sci ; 80(6): 149, 2023 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-37183204

RESUMO

STING acts as a cytosolic nucleotide sensor to trigger host defense upon viral or bacterial infection. While STING hyperactivation can exert anti-tumor effects by increasing T cell filtrates, in other contexts hyperactivation of STING can contribute to autoimmune and neuroinflammatory diseases. Several STING targeting agonists and a smaller subset of antagonists have been developed, yet STING targeted degraders, or PROTACs, remain largely underexplored. Here, we report a series of STING-agonist derived PROTACs that promote STING degradation in renal cell carcinoma (RCC) cells. We show that our STING PROTACs activate STING and target activated/phospho-STING for degradation. Locking STING on the endoplasmic reticulum via site-directed mutagenesis disables STING translocation to the proteasome and resultingly blocks STING degradation. We also demonstrate that PROTAC treatment blocks downstream innate immune signaling events and attenuates the anti-viral response. Interestingly, we find that VHL acts as a bona fide E3 ligase for STING in RCC; thus, VHL-recruiting STING PROTACs further promote VHL-dependent STING degradation. Our study reveals the design and biological assessment of VHL-recruiting agonist-derived STING PROTACs, as well as demonstrates an example of hijacking a physiological E3 ligase to enhance target protein degradation via distinct mechanisms.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Quimera de Direcionamento de Proteólise , Carcinoma de Células Renais/tratamento farmacológico , Ubiquitina-Proteína Ligases/metabolismo , Proteólise , Neoplasias Renais/tratamento farmacológico , Imunidade Inata , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo
5.
J Am Chem Soc ; 145(14): 8176-8188, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-36976643

RESUMO

Nuclear receptor-binding SET domain-containing 2 (NSD2) plays important roles in gene regulation, largely through its ability to dimethylate lysine 36 of histone 3 (H3K36me2). Despite aberrant activity of NSD2 reported in numerous cancers, efforts to selectively inhibit the catalytic activity of this protein with small molecules have been unsuccessful to date. Here, we report the development of UNC8153, a novel NSD2-targeted degrader that potently and selectively reduces the cellular levels of both NSD2 protein and the H3K36me2 chromatin mark. UNC8153 contains a simple warhead that confers proteasome-dependent degradation of NSD2 through a novel mechanism. Importantly, UNC8153-mediated reduction of H3K36me2 through the degradation of NSD2 results in the downregulation of pathological phenotypes in multiple myeloma cells including mild antiproliferative effects in MM1.S cells containing an activating point mutation and antiadhesive effects in KMS11 cells harboring the t(4;14) translocation that upregulates NSD2 expression.


Assuntos
Cromatina , Histonas , Histonas/metabolismo , Regulação da Expressão Gênica , Linhagem Celular Tumoral , Regulação para Baixo
6.
PLoS Pathog ; 17(2): e1009346, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33635929

RESUMO

Transcriptional silencing of HIV in CD4 T cells generates a reservoir of latently infected cells that can reseed infection after interruption of therapy. As such, these cells represent the principal barrier to curing HIV infection, but little is known about their characteristics. To further our understanding of the molecular mechanisms of latency, we characterized a primary cell model of HIV latency in which infected cells adopt heterogeneous transcriptional fates. In this model, we observed that latency is a stable, heritable state that is transmitted through cell division. Using Assay of Transposon-Accessible Chromatin sequencing (ATACseq) we found that latently infected cells exhibit greatly reduced proviral accessibility, indicating the presence of chromatin-based structural barriers to viral gene expression. By quantifying the activity of host cell transcription factors, we observe elevated activity of Forkhead and Kruppel-like factor transcription factors (TFs), and reduced activity of AP-1, RUNX and GATA TFs in latently infected cells. Interestingly, latency reversing agents with different mechanisms of action caused distinct patterns of chromatin reopening across the provirus. We observe that binding sites for the chromatin insulator CTCF are highly enriched in the differentially open chromatin of infected CD4 T cells. Furthermore, depletion of CTCF inhibited HIV latency, identifying this factor as playing a key role in the initiation or enforcement of latency. These data indicate that HIV latency develops preferentially in cells with a distinct pattern of TF activity that promotes a closed proviral structure and inhibits viral gene expression. Furthermore, these findings identify CTCF as a novel regulator of HIV latency.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Cromatina/metabolismo , Epigenômica/métodos , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , Fatores de Transcrição/metabolismo , Latência Viral , Sítios de Ligação , Linfócitos T CD4-Positivos/virologia , Cromatina/genética , Infecções por HIV/genética , Infecções por HIV/metabolismo , Infecções por HIV/virologia , Humanos , Células Jurkat , Fatores de Transcrição/genética , Ativação Viral
7.
PLoS Pathog ; 14(9): e1007267, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30212584

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of three human malignancies, the endothelial cell cancer Kaposi's sarcoma, and two B cell cancers, Primary Effusion Lymphoma and multicentric Castleman's disease. KSHV has latent and lytic phases of the viral life cycle, and while both contribute to viral pathogenesis, lytic proteins contribute to KSHV-mediated oncogenesis. Reactivation from latency is driven by the KSHV lytic gene transactivator RTA, and RTA transcription is controlled by epigenetic modifications. To identify host chromatin-modifying proteins that are involved in the latent to lytic transition, we screened a panel of inhibitors that target epigenetic regulatory proteins for their ability to stimulate KSHV reactivation. We found several novel regulators of viral reactivation: an inhibitor of Bmi1, PTC-209, two additional histone deacetylase inhibitors, Romidepsin and Panobinostat, and the bromodomain inhibitor (+)-JQ1. All of these compounds stimulate lytic gene expression, viral genome replication, and release of infectious virions. Treatment with Romidepsin, Panobinostat, and PTC-209 induces histone modifications at the RTA promoter, and results in nucleosome depletion at this locus. Finally, silencing Bmi1 induces KSHV reactivation, indicating that Bmi1, a member of the Polycomb repressive complex 1, is critical for maintaining KSHV latency.


Assuntos
Montagem e Desmontagem da Cromatina/fisiologia , Herpesvirus Humano 8/fisiologia , Ativação Viral/fisiologia , Latência Viral/fisiologia , Linhagem Celular , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Montagem e Desmontagem da Cromatina/genética , Depsipeptídeos/farmacologia , Epigênese Genética/efeitos dos fármacos , Genoma Viral/efeitos dos fármacos , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/patogenicidade , Compostos Heterocíclicos com 2 Anéis/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/fisiologia , Panobinostat/farmacologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/fisiologia , Regiões Promotoras Genéticas , Interferência de RNA , Tiazóis/farmacologia , Transativadores/genética , Transativadores/fisiologia , Ativação Viral/efeitos dos fármacos , Ativação Viral/genética , Latência Viral/genética
8.
Colorectal Dis ; 22(11): 1642-1648, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32654403

RESUMO

AIM: This is a systematic approach for minimally invasive methods in the management of mesh erosion after laparoscopic ventral mesh rectopexy. METHODS: All patients managed with organ-preserving techniques for mesh erosion were identified from a prospective database and clinical records were reviewed. Each patient was contacted via telephone and a structured questionnaire was applied. A Likert score was used to assess patient symptoms and overall satisfaction with management. One or more of the following techniques were used: (i) transanal or transvaginal trimming/excision of exposed mesh and sutures, with or without using transanal endoscopic micro surgery or transanal minimally invasive surgery; (ii) laparoscopic pelvic assessment and detachment of mesh from the sacral promontory. RESULTS: Eleven patients were managed for mesh erosion with organ-preserving techniques. All were women with a median age of 60 years [interquartile range (IQR) 53.5-68.5]. Vaginal, rectal, perineal erosion and recto-vaginal fistulation occurred in five, four, one and one patient respectively. Vaginal erosions presented at a median of 51 months (IQR 36-56) after index laparoscopic ventral mesh rectopexy compared to 17.5 months (IQR 14.5-27.25) for the rectal erosions. Median follow-up time was 24 months (IQR 19-49). Four of the meshes (36%) were removed completely whereas seven (63%) were partially removed. Vaginal erosions required a median of two procedures to achieve resolution as opposed to five for rectal. Out of 11 patients, eight were satisfied with the outcome of their management, whereas two were not and one remained ambivalent. CONCLUSION: An organ-sparing minimally invasive approach is feasible in managing mesh erosions but requires multiple procedures and months to complete.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Laparoscopia , Feminino , Humanos , Recém-Nascido , Laparoscopia/efeitos adversos , Reto , Telas Cirúrgicas/efeitos adversos , Vagina
9.
Prev Chronic Dis ; 17: E106, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32945769

RESUMO

This analysis provides prevalence estimates of diagnosed single and multiple (≥2) chronic conditions among the noninstitutionalized, civilian US adult population. Data from the 2018 National Health Interview Survey (NHIS) were used to estimate percentages for US adults by selected demographic characteristics. More than half (51.8%) of adults had at least 1 of 10 selected diagnosed chronic conditions (arthritis, cancer, chronic obstructive pulmonary disease, coronary heart disease, current asthma, diabetes, hepatitis, hypertension, stroke, and weak or failing kidneys), and 27.2% of US adults had multiple chronic conditions.


Assuntos
Inquéritos Epidemiológicos , Múltiplas Afecções Crônicas/epidemiologia , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estados Unidos/epidemiologia , Adulto Jovem
10.
J Asthma ; 56(3): 285-295, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29771597

RESUMO

OBJECTIVE: Agreement between administrative and survey data has been shown to vary by the condition of interest and there is limited research dedicated to parental report of asthma among children. The current study assesses the concordance between parent-reported asthma from the National Health Interview Survey (NHIS) with Medicaid administrative claims data among linkage eligible children from the NHIS. METHODS: Medicaid Analytic eXtract (MAX) files from the Centers for Medicare & Medicaid Services (CMS) (years 2000-2005) were linked to participants of the NHIS (years 2001-2005). Concordance measures were calculated to assess overall agreement between a claims-based asthma diagnosis and a survey-based asthma diagnosis. Structural equation modeling was used to assess the association between demographic, service utilization, and co-occurring conditions factors and agreement. RESULTS: Percent agreement between the two data sources was high (90%) with a prevalence-adjusted bias-adjusted kappa of 0.80 and Cohen's kappa of 0.55. Agreement varied by demographic characteristics, service utilization characteristics, and the presence of allergies and other health conditions. Structural equation modeling results found the presence of a series of co-occurring conditions, namely allergies, resulted in significantly lower agreement after controlling for demographics and service utilization. CONCLUSIONS: There was general agreement between asthma diagnoses reported in the NHIS when compared to medical claims. Discordance was greatest among children with co-occurring conditions.


Assuntos
Asma/epidemiologia , Inquéritos Epidemiológicos/estatística & dados numéricos , Revisão da Utilização de Seguros/estatística & dados numéricos , Medicaid/estatística & dados numéricos , Adolescente , Criança , Pré-Escolar , Comorbidade , Coleta de Dados/métodos , Coleta de Dados/estatística & dados numéricos , Feminino , Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Fatores Socioeconômicos , Estados Unidos/epidemiologia
11.
J Infect Dis ; 217(8): 1231-1236, 2018 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-29346585

RESUMO

Background: Bordetella pertussis is a human pathogen responsible for serious respiratory illness. The disease is most severe in infants too young to be vaccinated with most hospitalizations and deaths occurring within this age group. The Advisory Committee on Immunization Practices recommended immunization of pregnant women to protect infants from birth until their first vaccination at 6-8 weeks of age. We previously demonstrated that maternal vaccination with licensed acellular pertussis vaccines protected newborn baboons from disease. We hypothesized that protection was due to toxin-neutralizing, maternal anti-pertussis toxin antibodies and predicted that maternal vaccination with a pertussis toxoid (PTx)-only vaccine would protect newborns from disease. Methods: Infant baboons born to unvaccinated mothers or mothers vaccinated with a PTx-only vaccine were challenged with B. pertussis at 5 weeks of age and followed for infection and signs of disease. Results: Although all challenged infants were heavily colonized, the infant baboons born to mothers vaccinated with PTx-only vaccine were free from clinical disease following exposure to B. pertussis. In contrast, disease was observed in infants born to unvaccinated mothers. Conclusions: Our results demonstrated that maternal vaccination with a PTx-only vaccine is sufficient to protect newborn baboons from disease following exposure to pertussis.


Assuntos
Imunidade Materno-Adquirida/imunologia , Vacina contra Coqueluche/imunologia , Coqueluche/prevenção & controle , Animais , Carga Bacteriana , Bordetella parapertussis , Modelos Animais de Doenças , Feminino , Papio , Gravidez
12.
Biochemistry ; 57(14): 2140-2149, 2018 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-29558110

RESUMO

Multivalent binding is an efficient means to enhance the affinity and specificity of chemical probes targeting multidomain proteins in order to study their function and role in disease. While the theory of multivalent binding is straightforward, physical and structural characterization of bivalent binding encounters multiple technical difficulties. We present a case study where a combination of experimental techniques and computational simulations was used to comprehensively characterize the binding and structure-affinity relationships for a series of Bromosporine-based bivalent bromodomain ligands with a bivalent protein, Transcription Initiation Factor TFIID subunit 1 (TAF1). Experimental techniques-Isothermal Titration Calorimetry, X-ray Crystallography, Circular Dichroism, Size Exclusion Chromatography-Multi-Angle Light Scattering, and Surface Plasmon Resonance-were used to determine structures, binding affinities, and kinetics of monovalent ligands and bivalent ligands with varying linker lengths. The experimental data for monomeric ligands were fed into explicit computational simulations, in which both ligand and protein species were present in a broad range of concentrations, and in up to a 100 s time regime, to match experimental conditions. These simulations provided accurate estimates for apparent affinities (in good agreement with experimental data), individual dissociation microconstants and other microscopic details for each type of protein-ligand complex. We conclude that the expected efficiency of bivalent ligands in a cellular context is difficult to estimate by a single technique in vitro, due to higher order associations favored at the concentrations used, and other complicating processes. Rather, a combination of structural, biophysical, and computational approaches should be utilized to estimate and characterize multivalent interactions.


Assuntos
Histona Acetiltransferases/química , Fatores Associados à Proteína de Ligação a TATA/química , Fator de Transcrição TFIID/química , Calorimetria , Cristalografia por Raios X , Difusão Dinâmica da Luz , Histona Acetiltransferases/metabolismo , Humanos , Sondas Moleculares/metabolismo , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fator de Transcrição TFIID/metabolismo
13.
Infect Immun ; 86(11)2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30126900

RESUMO

Pertussis is a severe respiratory disease caused by Bordetella pertussis The classic symptoms of pertussis include paroxysmal coughing with an inspiratory whoop, posttussive vomiting, cyanosis, and persistent coryzal symptoms. Infants under 2 months of age experience more severe disease, with most deaths occurring in this age group. Most of what is known about the pathology of pertussis in humans is from the evaluation of fatal human infant cases. The baboon model of pertussis provides the opportunity to evaluate the histopathology of severe but nonfatal pertussis. The baboon model recapitulates the characteristic clinical signs of pertussis observed in humans, including leukocytosis, paroxysmal coughing, mucus production, heavy colonization of the airway, and transmission of the bacteria between hosts. As in humans, baboons demonstrate age-related differences in clinical presentation, with younger animals experiencing more severe disease. We examined the histopathology of 5- to 6-week-old baboons, with the findings being similar to those reported for fatal human infant cases. In juvenile baboons, we found that the disease is highly inflammatory and concentrated to the lungs with signs of disease that would typically be diagnosed as acute respiratory distress syndrome (ARDS) and bronchopneumonia. In contrast, no significant pathology was observed in the trachea. Histopathological changes in the trachea were limited to cellular infiltrates and mucus production. Immunohistostaining revealed that the bacteria were localized to the surface of the ciliated epithelium in the conducting airways. Our observations provide important insights into the pathology of pertussis in typical, severe but nonfatal pertussis cases in a very relevant animal model.


Assuntos
Bordetella pertussis/crescimento & desenvolvimento , Pulmão/patologia , Coqueluche/patologia , Animais , Modelos Animais de Doenças , Histocitoquímica , Imuno-Histoquímica , Papio , Traqueia/patologia
14.
Am J Physiol Lung Cell Mol Physiol ; 314(5): L822-L834, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29368547

RESUMO

Smoke inhalation associated with structural fires, wildfires, or explosions leads to lung injury, for which innovative and clinically relevant animal models are needed to develop effective therapeutics. We have previously reported that damage-associated molecular patterns (DAMPs) and anti-inflammatory cytokines correlate with infectious complications in patients diagnosed with inhalational injury. In this study, we describe a novel and translational murine model of acute inhalational injury characterized by an accumulation of protein and neutrophils in the bronchoalveolar space, as well as histological evidence of tissue damage. Mice were anesthetized, and a cannula was placed in the trachea and exposed to smoldering plywood smoke three times for 2-min intervals in a smoke chamber. Here we demonstrate that this model recapitulates clinically relevant phenotypes, including early release of double-stranded DNA (dsDNA), IL-10, monocyte chemoattractant protein (MCP)-1, and CXCL1 along with neutrophilia early after injury, accompanied by subsequent susceptibility to opportunistic infection with Pseudomonas aeruginosa. Further investigation of the model, and in turn a reanalysis of patient samples, revealed a late release of the DAMP hyaluronic acid (HA) from the lung. Using nitric oxide synthase-deficient mice, we found that Nos2 was required for increases in IL-10, MCP-1, and HA following injury but not release of dsDNA, CXCL1 expression, early neutrophilia, or susceptibility to opportunistic infection. Depletion of CXCL1 attenuated early neutrophil recruitment, leading to decreased histopathology scores and improved bacterial clearance in this model of smoke inhalation. Together, these data highlight the potential therapeutic benefit of attenuating neutrophil recruitment in the first 24 h after injury in patients.


Assuntos
Lesão Pulmonar Aguda/imunologia , Infecções Bacterianas/complicações , Quimiocina CXCL1/metabolismo , Pulmão/imunologia , Infiltração de Neutrófilos/imunologia , Fumaça/efeitos adversos , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/microbiologia , Lesão Pulmonar Aguda/patologia , Administração por Inalação , Animais , Infecções Bacterianas/microbiologia , Líquido da Lavagem Broncoalveolar , Células Cultivadas , Citocinas/metabolismo , Humanos , Pulmão/metabolismo , Pulmão/microbiologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
15.
Br J Surg ; 105(10): 1359-1367, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29663330

RESUMO

BACKGROUND: Decreasing anastomotic leak rates remain a major goal in colorectal surgery. Assessing intraoperative perfusion by indocyanine green (ICG) with near-infrared (NIR) visualization may assist in selection of intestinal transection level and subsequent anastomotic vascular sufficiency. This study examined the use of NIR-ICG imaging in colorectal surgery. METHODS: This was a prospective phase II study (NCT02459405) of non-selected patients undergoing any elective colorectal operation with anastomosis over a 3-year interval in three tertiary hospitals. A standard protocol was followed to assess NIR-ICG perfusion before and after anastomosis construction in comparison with standard operator visual assessment alone. RESULTS: Five hundred and four patients (median age 64 years, 279 men) having surgery for neoplastic (330) and benign (174) pathology were studied. Some 425 operations (85·3 per cent) were started laparoscopically, with a conversion rate of 5·9 per cent. In all, 220 patients (43·7 per cent) underwent high anterior resection or reversal of Hartmann's operation, and 90 (17·9 per cent) low anterior resection. ICG angiography was achieved in every patient, with a median interval of 29 s to visualization of the signal after injection. NIR-ICG assessment resulted in a change in the site of bowel division in 29 patients (5·8 per cent) with no subsequent leaks in these patients. Leak rates were 2·4 per cent overall (12 of 504), 2·6 per cent for colorectal anastomoses and 3 per cent for low anterior resection. When NIR-ICG imaging was used, the anastomotic leak rates were lower than those in the participating centres from over 1000 similar operations performed with identical technique but without NIR-ICG technology. CONCLUSION: Routine NIR-ICG assessment in patients undergoing elective colorectal surgery is feasible. NIR-ICG use may change intraoperative decisions, which may lead to a reduction in anastomotic leak rates.


Assuntos
Fístula Anastomótica/prevenção & controle , Colectomia , Procedimentos Cirúrgicos Eletivos , Cuidados Intraoperatórios/métodos , Protectomia , Espectroscopia de Luz Próxima ao Infravermelho , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anastomose Cirúrgica , Fístula Anastomótica/epidemiologia , Feminino , Corantes Fluorescentes , Humanos , Verde de Indocianina , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
16.
Nat Chem Biol ; 12(3): 180-7, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26807715

RESUMO

We report the design and characterization of UNC3866, a potent antagonist of the methyllysine (Kme) reading function of the Polycomb CBX and CDY families of chromodomains. Polycomb CBX proteins regulate gene expression by targeting Polycomb repressive complex 1 (PRC1) to sites of H3K27me3 via their chromodomains. UNC3866 binds the chromodomains of CBX4 and CBX7 most potently, with a K(d) of ∼100 nM for each, and is 6- to 18-fold selective as compared to seven other CBX and CDY chromodomains while being highly selective over >250 other protein targets. X-ray crystallography revealed that UNC3866's interactions with the CBX chromodomains closely mimic those of the methylated H3 tail. UNC4195, a biotinylated derivative of UNC3866, was used to demonstrate that UNC3866 engages intact PRC1 and that EED incorporation into PRC1 is isoform dependent in PC3 prostate cancer cells. Finally, UNC3866 inhibits PC3 cell proliferation, consistent with the known ability of CBX7 overexpression to confer a growth advantage, whereas UNC4219, a methylated negative control compound, has negligible effects.


Assuntos
Oligopeptídeos/farmacologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/genética , Animais , Disponibilidade Biológica , Biotinilação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Regulação da Expressão Gênica/genética , Humanos , Isomerismo , Ligases , Masculino , Metilação , Camundongos , Modelos Moleculares , Complexo Repressor Polycomb 1/biossíntese , Complexo Repressor Polycomb 1/metabolismo , Proteínas do Grupo Polycomb/genética , Proteínas do Grupo Polycomb/metabolismo , Especificidade por Substrato , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
18.
Neurobiol Learn Mem ; 146: 37-46, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29032015

RESUMO

BACKGROUND: ε4 allele possession is associated with an increased risk of Alzheimer's disease. Its effects earlier in life are less well understood. Previous studies have reported both detrimental effects and a lack of effect on cognition outside dementia. We used genotype based recall from the ALSPAC study to investigate whether APOE genotype influences cognition in earlier adult life. METHODS: We invited all individuals with the rarer ε22 or ε44 genotypes and equal numbers of those with ε32, ε33 or ε34 APOE genotypes (total n invited = 1936, ages 23-67). Participants were screened for dementia using the Addenbrooke's Cognitive Examination Revised (ACE-R). Participants were asked to complete a 3 h battery of neuropsychological tests covering a range of cognitive domains. The primary outcome was performance on the Rey Auditory Verbal Learning Test (RAVLT). Transformation of variables was used where required to permit parametric testing. As genotypes are unlikely to be confounded unadjusted analyses were performed. RESULTS: 114 participants were recruited to the study (39 ε33, 27 ε34, 15 ε44, 26 ε32 & 7 ε22). ε4+ participants had higher scores on the cognitive failures questionnaire (10 point increase, p = 0.006) but no deficits on objective cognitive testing. ε2 carriers had slightly better episodic memory performance (p = 0.016), slightly improved n-back accuracy and better executive functioning (trails A&B, p = 0.005). CONCLUSIONS: It is intriguing that the ε2+ group performed better as this group have a lower risk of Alzheimer's disease. Most previous studies have analysed as ε4/non ε4 so may have missed this effect.


Assuntos
Apolipoproteína E2/genética , Apolipoproteína E4/genética , Cognição/fisiologia , Função Executiva/fisiologia , Memória Episódica , Aprendizagem Verbal/fisiologia , Adulto , Idoso , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Reino Unido , Adulto Jovem
19.
Colorectal Dis ; 19(9): O345-O349, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28710784

RESUMO

AIM: Surgical management of rectal prolapse varies considerably. Most surgeons are reluctant to use ventral mesh rectopexy in young women until they have completed their family. The aim of the present study was to review outcomes of pregnancy following laparoscopic ventral mesh rectopexy from a tertiary referral centre over a 10-year period (2006-2016) and to review the impact on pelvic floor symptoms. METHOD: We undertook a retrospective review of a prospectively compiled database of patients who had undergone laparoscopic ventral rectopexy in a single centre over a 10-year period. Pelvic floor symptom scores (Vaizey for incontinence and Longo for obstructive defaecation) were collected at initial presentation (pre-intervention), post-intervention and after child birth. RESULTS: In all, 954 rectopexies were performed over this 10-year period. 225 (24%) patients were women and under 45 years of age (taken as an arbitrary cut-off for decreased likelihood of pregnancy). Eight (4%) of these patients became pregnant following rectopexy. The interval between rectopexy and delivery was 42 months (21-50). Six patients delivered live babies by elective lower segment caesarean section and two by spontaneous vaginal delivery. Six were first babies and two were second. No mesh related adverse outcome was reported. No difference in pelvic floor symptoms was demonstrated on comparison of post-rectopexy and post-delivery scores. CONCLUSION: This study provides the first description in the English language literature of safe delivery by elective lower segment caesarean section or spontaneous vaginal delivery following laparoscopic ventral mesh rectopexy. No adverse impact on pelvic floor related quality of life was detected.


Assuntos
Laparoscopia/efeitos adversos , Complicações Pós-Operatórias/etiologia , Complicações na Gravidez/etiologia , Prolapso Retal/cirurgia , Reto/cirurgia , Telas Cirúrgicas/efeitos adversos , Adulto , Cesárea , Bases de Dados Factuais , Parto Obstétrico/métodos , Feminino , Humanos , Laparoscopia/métodos , Parto , Complicações Pós-Operatórias/cirurgia , Período Pós-Operatório , Gravidez , Complicações na Gravidez/cirurgia , Resultado da Gravidez , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
20.
Colorectal Dis ; 19(7): 681-689, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27943522

RESUMO

AIM: Advances in laparoscopic techniques combined with enhanced recovery pathways have led to faster recuperation and discharge after colorectal surgery. Peripheral nerve blockade using transversus abdominis plane (TAP) blocks reduce opioid requirements and provide better analgesia for laparoscopic colectomies than do inactive controls. This double-blind randomized study was performed to compare TAP blocks using bupivacaine with standardized wound infiltration with local anaesthetic (LA). METHOD: Seventy-one patients were randomized to receive either TAP block or wound infiltration. The TAP blocks were performed by experienced anaesthetists who used ultrasound guidance to deliver 40 ml of 0.25% bupivacaine post-induction into the transverse abdominis plane. In the control group, 40 ml of 0.25% bupivacaine was injected around the trocar and the extraction site by the surgeon. Both groups received patient-controlled analgesia (PCA) with intravenous morphine. Patients and nursing staff assessed pain scores 6, 12, 24 and 48 h after surgery. The primary outcome was overall morphine use in the first 48 h. RESULTS: Of the 71 patients, 20 underwent a right hemicolectomy and 51 a high anterior resection. The modified intention-to-treat analysis showed no significant differences in overall morphine use [47.3 (36.2-58.5) mg vs 46.7 (36.2-57.3) mg; mean (95% CI), P = 0.8663] in the first 48 h. Pain scores were similar at 6, 12, 24 and 48 h. No differences were found regarding time to mobilization, resumption of diet and length of hospital stay. CONCLUSION: In elective laparoscopic colectomies, standardized wound infiltration with LA has the same analgesic effect as TAP blocks post-induction using bupivacaine at 48 h.


Assuntos
Anestésicos Locais/administração & dosagem , Colectomia/efeitos adversos , Laparoscopia/efeitos adversos , Bloqueio Nervoso/métodos , Dor Pós-Operatória/tratamento farmacológico , Idoso , Bupivacaína/administração & dosagem , Colectomia/métodos , Método Duplo-Cego , Feminino , Humanos , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Dor Pós-Operatória/etiologia , Ferida Cirúrgica , Resultado do Tratamento , Ultrassonografia de Intervenção/métodos
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