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1.
Cell ; 184(17): 4447-4463.e20, 2021 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-34363755

RESUMEN

TANK binding kinase 1 (TBK1) regulates IFN-I, NF-κB, and TNF-induced RIPK1-dependent cell death (RCD). In mice, biallelic loss of TBK1 is embryonically lethal. We discovered four humans, ages 32, 26, 7, and 8 from three unrelated consanguineous families with homozygous loss-of-function mutations in TBK1. All four patients suffer from chronic and systemic autoinflammation, but not severe viral infections. We demonstrate that TBK1 loss results in hypomorphic but sufficient IFN-I induction via RIG-I/MDA5, while the system retains near intact IL-6 induction through NF-κB. Autoinflammation is driven by TNF-induced RCD as patient-derived fibroblasts experienced higher rates of necroptosis in vitro, and CC3 was elevated in peripheral blood ex vivo. Treatment with anti-TNF dampened the baseline circulating inflammatory profile and ameliorated the clinical condition in vivo. These findings highlight the plasticity of the IFN-I response and underscore a cardinal role for TBK1 in the regulation of RCD.


Asunto(s)
Inflamación/enzimología , Proteínas Serina-Treonina Quinasas/deficiencia , Factor de Necrosis Tumoral alfa/farmacología , Células A549 , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Apoptosis , Autoinmunidad/efectos de los fármacos , Encéfalo/diagnóstico por imagen , Muerte Celular/efectos de los fármacos , Citocinas/metabolismo , Enzima Desubiquitinante CYLD/metabolismo , Femenino , Células HEK293 , Homocigoto , Humanos , Quinasa I-kappa B/metabolismo , Inmunofenotipificación , Inflamación/patología , Interferón Tipo I/metabolismo , Interferón gamma/metabolismo , Mutación con Pérdida de Función/genética , Masculino , Linaje , Fosforilación/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Receptores de Reconocimiento de Patrones/metabolismo , Receptor Toll-Like 3/metabolismo , Transcriptoma/genética , Vesiculovirus/efectos de los fármacos , Vesiculovirus/fisiología
2.
Mol Cell ; 83(22): 4047-4061.e6, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37977117

RESUMEN

CDK4/6 inhibitors are remarkable anti-cancer drugs that can arrest tumor cells in G1 and induce their senescence while causing only relatively mild toxicities in healthy tissues. How they achieve this mechanistically is unclear. We show here that tumor cells are specifically vulnerable to CDK4/6 inhibition because during the G1 arrest, oncogenic signals drive toxic cell overgrowth. This overgrowth causes permanent cell cycle withdrawal by either preventing progression from G1 or inducing genotoxic damage during the subsequent S-phase and mitosis. Inhibiting or reverting oncogenic signals that converge onto mTOR can rescue this excessive growth, DNA damage, and cell cycle exit in cancer cells. Conversely, inducing oncogenic signals in non-transformed cells can drive these toxic phenotypes and sensitize the cells to CDK4/6 inhibition. Together, this demonstrates that cell cycle arrest and oncogenic cell growth is a synthetic lethal combination that is exploited by CDK4/6 inhibitors to induce tumor-specific toxicity.


Asunto(s)
Antineoplásicos , Neoplasias , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Puntos de Control de la Fase G1 del Ciclo Celular , Proteína p53 Supresora de Tumor/genética , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Antineoplásicos/farmacología , Neoplasias/tratamiento farmacológico , Neoplasias/genética
3.
Mol Cell ; 83(22): 4062-4077.e5, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37977118

RESUMEN

Abnormal increases in cell size are associated with senescence and cell cycle exit. The mechanisms by which overgrowth primes cells to withdraw from the cell cycle remain unknown. We address this question using CDK4/6 inhibitors, which arrest cells in G0/G1 and are licensed to treat advanced HR+/HER2- breast cancer. We demonstrate that CDK4/6-inhibited cells overgrow during G0/G1, causing p38/p53/p21-dependent cell cycle withdrawal. Cell cycle withdrawal is triggered by biphasic p21 induction. The first p21 wave is caused by osmotic stress, leading to p38- and size-dependent accumulation of p21. CDK4/6 inhibitor washout results in some cells entering S-phase. Overgrown cells experience replication stress, resulting in a second p21 wave that promotes cell cycle withdrawal from G2 or the subsequent G1. We propose that the levels of p21 integrate signals from overgrowth-triggered stresses to determine cell fate. This model explains how hypertrophy can drive senescence and why CDK4/6 inhibitors have long-lasting effects in patients.


Asunto(s)
Proteína p53 Supresora de Tumor , Humanos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Ciclo Celular , División Celular , Proteína p53 Supresora de Tumor/genética , Quinasa 4 Dependiente de la Ciclina/genética , Quinasa 4 Dependiente de la Ciclina/metabolismo
4.
EMBO J ; 42(20): e112630, 2023 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-37712330

RESUMEN

Two major mechanisms safeguard genome stability during mitosis: the mitotic checkpoint delays mitosis until all chromosomes have attached to microtubules, and the kinetochore-microtubule error-correction pathway keeps this attachment process free from errors. We demonstrate here that the optimal strength and dynamics of these processes are set by a kinase-phosphatase pair (PLK1-PP2A) that engage in negative feedback from adjacent phospho-binding motifs on the BUB complex. Uncoupling this feedback to skew the balance towards PLK1 produces a strong checkpoint, hypostable microtubule attachments and mitotic delays. Conversely, skewing the balance towards PP2A causes a weak checkpoint, hyperstable microtubule attachments and chromosome segregation errors. These phenotypes are associated with altered BUB complex recruitment to KNL1-MELT motifs, implicating PLK1-PP2A in controlling auto-amplification of MELT phosphorylation. In support, KNL1-BUB disassembly becomes contingent on PLK1 inhibition when KNL1 is engineered to contain excess MELT motifs. This elevates BUB-PLK1/PP2A complex levels on metaphase kinetochores, stabilises kinetochore-microtubule attachments, induces chromosome segregation defects and prevents KNL1-BUB disassembly at anaphase. Together, these data demonstrate how a bifunctional PLK1/PP2A module has evolved together with the MELT motifs to optimise BUB complex dynamics and ensure accurate chromosome segregation.


Asunto(s)
Cinetocoros , Puntos de Control de la Fase M del Ciclo Celular , Humanos , Cinetocoros/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Segregación Cromosómica , Fosforilación , Microtúbulos/metabolismo , Mitosis , Células HeLa
5.
Nature ; 592(7854): 444-449, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33762736

RESUMEN

Nonalcoholic steatohepatitis (NASH) is a manifestation of systemic metabolic disease related to obesity, and causes liver disease and cancer1,2. The accumulation of metabolites leads to cell stress and inflammation in the liver3, but mechanistic understandings of liver damage in NASH are incomplete. Here, using a preclinical mouse model that displays key features of human NASH (hereafter, NASH mice), we found an indispensable role for T cells in liver immunopathology. We detected the hepatic accumulation of CD8 T cells with phenotypes that combined tissue residency (CXCR6) with effector (granzyme) and exhaustion (PD1) characteristics. Liver CXCR6+ CD8 T cells were characterized by low activity of the FOXO1 transcription factor, and were abundant in NASH mice and in patients with NASH. Mechanistically, IL-15 induced FOXO1 downregulation and CXCR6 upregulation, which together rendered liver-resident CXCR6+ CD8 T cells susceptible to metabolic stimuli (including acetate and extracellular ATP) and collectively triggered auto-aggression. CXCR6+ CD8 T cells from the livers of NASH mice or of patients with NASH had similar transcriptional signatures, and showed auto-aggressive killing of cells in an MHC-class-I-independent fashion after signalling through P2X7 purinergic receptors. This killing by auto-aggressive CD8 T cells fundamentally differed from that by antigen-specific cells, which mechanistically distinguishes auto-aggressive and protective T cell immunity.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Hígado/inmunología , Hígado/patología , Enfermedad del Hígado Graso no Alcohólico/inmunología , Enfermedad del Hígado Graso no Alcohólico/patología , Receptores CXCR6/inmunología , Acetatos/farmacología , Animales , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/patología , Muerte Celular/efectos de los fármacos , Muerte Celular/inmunología , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Humanos , Interleucina-15/inmunología , Interleucina-15/farmacología , Hígado/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL
6.
EMBO J ; 41(6): e108599, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35037284

RESUMEN

CDK4/6 inhibitors arrest the cell cycle in G1-phase. They are approved to treat breast cancer and are also undergoing clinical trials against a range of other tumour types. To facilitate these efforts, it is important to understand why a cytostatic arrest in G1 causes long-lasting effects on tumour growth. Here, we demonstrate that a prolonged G1 arrest following CDK4/6 inhibition downregulates replisome components and impairs origin licencing. Upon release from that arrest, many cells fail to complete DNA replication and exit the cell cycle in a p53-dependent manner. If cells fail to withdraw from the cell cycle following DNA replication problems, they enter mitosis and missegregate chromosomes causing excessive DNA damage, which further limits their proliferative potential. These effects are observed in a range of tumour types, including breast cancer, implying that genotoxic stress is a common outcome of CDK4/6 inhibition. This unanticipated ability of CDK4/6 inhibitors to induce DNA damage now provides a rationale to better predict responsive tumour types and effective combination therapies, as demonstrated by the fact that CDK4/6 inhibition induces sensitivity to chemotherapeutics that also cause replication stress.


Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Ciclo Celular , División Celular , Línea Celular Tumoral , Quinasa 4 Dependiente de la Ciclina/genética , Quinasa 6 Dependiente de la Ciclina/genética , Femenino , Fase G1 , Humanos
8.
Mol Cell ; 72(1): 162-177.e7, 2018 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-30244833

RESUMEN

Histone post-translational modifications (PTMs) are important genomic regulators often studied by chromatin immunoprecipitation (ChIP), whereby their locations and relative abundance are inferred by antibody capture of nucleosomes and associated DNA. However, the specificity of antibodies within these experiments has not been systematically studied. Here, we use histone peptide arrays and internally calibrated ChIP (ICeChIP) to characterize 52 commercial antibodies purported to distinguish the H3K4 methylforms (me1, me2, and me3, with each ascribed distinct biological functions). We find that many widely used antibodies poorly distinguish the methylforms and that high- and low-specificity reagents can yield dramatically different biological interpretations, resulting in substantial divergence from the literature for numerous H3K4 methylform paradigms. Using ICeChIP, we also discern quantitative relationships between enhancer H3K4 methylation and promoter transcriptional output and can measure global PTM abundance changes. Our results illustrate how poor antibody specificity contributes to the "reproducibility crisis," demonstrating the need for rigorous, platform-appropriate validation.


Asunto(s)
Anticuerpos/genética , Inmunoprecipitación de Cromatina/métodos , Heterocromatina/genética , Histonas/genética , Anticuerpos/química , Anticuerpos/inmunología , Especificidad de Anticuerpos , Heterocromatina/química , Heterocromatina/inmunología , Código de Histonas/genética , Histonas/química , Histonas/inmunología , Humanos , Metilación , Nucleosomas/genética , Regiones Promotoras Genéticas/genética , Procesamiento Proteico-Postraduccional/genética
9.
Nature ; 567(7746): 123-126, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30814733

RESUMEN

Cannabis sativa L. has been cultivated and used around the globe for its medicinal properties for millennia1. Some cannabinoids, the hallmark constituents of Cannabis, and their analogues have been investigated extensively for their potential medical applications2. Certain cannabinoid formulations have been approved as prescription drugs in several countries for the treatment of a range of human ailments3. However, the study and medicinal use of cannabinoids has been hampered by the legal scheduling of Cannabis, the low in planta abundances of nearly all of the dozens of known cannabinoids4, and their structural complexity, which limits bulk chemical synthesis. Here we report the complete biosynthesis of the major cannabinoids cannabigerolic acid, Δ9-tetrahydrocannabinolic acid, cannabidiolic acid, Δ9-tetrahydrocannabivarinic acid and cannabidivarinic acid in Saccharomyces cerevisiae, from the simple sugar galactose. To accomplish this, we engineered the native mevalonate pathway to provide a high flux of geranyl pyrophosphate and introduced a heterologous, multi-organism-derived hexanoyl-CoA biosynthetic pathway5. We also introduced the Cannabis genes that encode the enzymes involved in the biosynthesis of olivetolic acid6, as well as the gene for a previously undiscovered enzyme with geranylpyrophosphate:olivetolate geranyltransferase activity and the genes for corresponding cannabinoid synthases7,8. Furthermore, we established a biosynthetic approach that harnessed the promiscuity of several pathway genes to produce cannabinoid analogues. Feeding different fatty acids to our engineered strains yielded cannabinoid analogues with modifications in the part of the molecule that is known to alter receptor binding affinity and potency9. We also demonstrated that our biological system could be complemented by simple synthetic chemistry to further expand the accessible chemical space. Our work presents a platform for the production of natural and unnatural cannabinoids that will allow for more rigorous study of these compounds and could be used in the development of treatments for a variety of human health problems.


Asunto(s)
Vías Biosintéticas , Cannabinoides/biosíntesis , Cannabinoides/química , Cannabis/química , Ingeniería Metabólica , Saccharomyces cerevisiae/metabolismo , Acilcoenzima A/biosíntesis , Transferasas Alquil y Aril/genética , Transferasas Alquil y Aril/metabolismo , Benzoatos/metabolismo , Vías Biosintéticas/genética , Cannabinoides/metabolismo , Cannabis/genética , Dronabinol/análogos & derivados , Dronabinol/metabolismo , Fermentación , Galactosa/metabolismo , Ácido Mevalónico/metabolismo , Fosfatos de Poliisoprenilo/biosíntesis , Fosfatos de Poliisoprenilo/metabolismo , Saccharomyces cerevisiae/genética , Salicilatos/metabolismo
10.
PLoS Genet ; 18(11): e1010496, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36346812

RESUMEN

Bone and muscle are coupled through developmental, mechanical, paracrine, and autocrine signals. Genetic variants at the CPED1-WNT16 locus are dually associated with bone- and muscle-related traits. While Wnt16 is necessary for bone mass and strength, this fails to explain pleiotropy at this locus. Here, we show wnt16 is required for spine and muscle morphogenesis in zebrafish. In embryos, wnt16 is expressed in dermomyotome and developing notochord, and contributes to larval myotome morphology and notochord elongation. Later, wnt16 is expressed at the ventral midline of the notochord sheath, and contributes to spine mineralization and osteoblast recruitment. Morphological changes in wnt16 mutant larvae are mirrored in adults, indicating that wnt16 impacts bone and muscle morphology throughout the lifespan. Finally, we show that wnt16 is a gene of major effect on lean mass at the CPED1-WNT16 locus. Our findings indicate that Wnt16 is secreted in structures adjacent to developing bone (notochord) and muscle (dermomyotome) where it affects the morphogenesis of each tissue, thereby rendering wnt16 expression into dual effects on bone and muscle morphology. This work expands our understanding of wnt16 in musculoskeletal development and supports the potential for variants to act through WNT16 to influence bone and muscle via parallel morphogenetic processes.


Asunto(s)
Notocorda , Pez Cebra , Animales , Pez Cebra/genética , Columna Vertebral , Músculos , Morfogénesis/genética , Larva , Proteínas de Pez Cebra/genética , Proteínas Wnt/genética
11.
Breast Cancer Res ; 26(1): 35, 2024 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-38429789

RESUMEN

BACKGROUND: Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with a poor prognosis. Doxorubicin is part of standard curative therapy for TNBC, but chemotherapy resistance remains an important clinical challenge. Bocodepsin (OKI-179) is a small molecule class I histone deacetylase (HDAC) inhibitor that promotes apoptosis in TNBC preclinical models. The purpose of this study was to investigate the combination of bocodepsin and doxorubicin in preclinical TNBC models and evaluate the impact on terminal cell fate, including apoptosis and senescence. METHODS: TNBC cell lines were treated with doxorubicin and CellTiter-Glo was used to assess proliferation and determine doxorubicin sensitivity. Select cell lines were treated with OKI-005 (in vitro version of bocodepsin) and doxorubicin and assessed for proliferation, apoptosis as measured by Annexin V/PI, and cell cycle by flow cytometry. Immunoblotting was used to assess changes in mediators of apoptosis, cell cycle arrest, and senescence. Senescence was measured by the senescence-associated ß-galactosidase assay. An MDA-MB-231 xenograft in vivo model was treated with bocodepsin, doxorubicin, or the combination and assessed for inhibition of tumor growth. shRNA knockdown of p53 was performed in the CAL-51 cell line and proliferation, apoptosis and senescence were assessed in response to combination treatment. RESULTS: OKI-005 and doxorubicin resulted in synergistic antiproliferative activity in TNBC cells lines regardless of p53 mutation status. The combination led to increased apoptosis and decreased senescence. In vivo, the combination resulted in increased tumor growth inhibition compared to either single agent. shRNA knock-down of p53 led to increased doxorubicin-induced senescence that was decreased with the addition of OKI-005 in vitro. CONCLUSION: The addition of bocodepsin to doxorubicin resulted in synergistic antiproliferative activity in vitro, improved tumor growth inhibition in vivo, and promotion of apoptosis which makes this a promising combination to overcome doxorubicin resistance in TNBC. Bocodepsin is currently in clinical development and has a favorable toxicity profile compared to other HDAC inhibitors supporting the feasibility of evaluating this combination in patients with TNBC.


Asunto(s)
Inhibidores de Histona Desacetilasas , Neoplasias de la Mama Triple Negativas , Humanos , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/metabolismo , Proteína p53 Supresora de Tumor/genética , Doxorrubicina/farmacología , Doxorrubicina/uso terapéutico , Apoptosis , ARN Interferente Pequeño
12.
EMBO J ; 39(12): e103180, 2020 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-32202322

RESUMEN

Cyclin B:CDK1 is the master kinase regulator of mitosis. We show here that, in addition to its kinase functions, mammalian Cyclin B also scaffolds a localised signalling pathway to help preserve genome stability. Cyclin B1 localises to an expanded region of the outer kinetochore, known as the corona, where it scaffolds the spindle assembly checkpoint (SAC) machinery by binding directly to MAD1. In vitro reconstitutions map the key binding interface to a few acidic residues in the N-terminal region of MAD1, and point mutations in this sequence abolish MAD1 corona localisation and weaken the SAC. Therefore, Cyclin B1 is the long-sought-after scaffold that links MAD1 to the corona, and this specific pool of MAD1 is needed to generate a robust SAC response. Robustness arises because Cyclin B1:MAD1 localisation loses dependence on MPS1 kinase after the corona has been established, ensuring that corona-localised MAD1 can still be phosphorylated when MPS1 activity is low. Therefore, this study explains how corona-MAD1 generates a robust SAC signal, and it reveals a scaffolding role for the key mitotic kinase, Cyclin B1:CDK1, which ultimately helps to inhibit its own degradation.


Asunto(s)
Puntos de Control del Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Ciclina B1/metabolismo , Cinetocoros/metabolismo , Mitosis , Proteína Quinasa CDC2/genética , Proteína Quinasa CDC2/metabolismo , Proteínas de Ciclo Celular/genética , Ciclina B1/genética , Células HeLa , Humanos , Mutación Puntual , Dominios Proteicos
13.
Ann Surg ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38920042

RESUMEN

OBJECTIVE: The aim was to analyze the learning curves of minimal invasive liver surgery(MILS) and propose a standardized reporting. SUMMARY BACKGROUND DATA: MILS offers benefits compared to open resections. For a safe introduction along the learning curve, formal training is recommended. However, definitions of learning curves and methods to assess it lack standardization. METHODS: A systematic review of PubMed, Web of Science, and CENTRAL databases identified studies on learning curves in MILS. The primary outcome was the number needed to overcome the learning curve. Secondary outcomes included endpoints defining learning curves, and characterization of different learning phases(competency, proficiency and mastery). RESULTS: 60 articles with 12'241 patients and 102 learning curve analyses were included. The laparoscopic and robotic approach was evaluated in 71 and 18 analyses and both approaches combined in 13 analyses. Sixty-one analyses (60%) based the learning curve on statistical calculations. The most often used parameters to define learning curves were operative time (n=64), blood loss (n=54), conversion (n=42) and postoperative complications (n=38). Overall competency, proficiency and mastery were reached after 34 (IQR 19-56), 50 (IQR 24-74), 58 (IQR 24-100) procedures respectively. Intraoperative parameters improved earlier (operative time: competency to proficiency to mastery: -13%, 2%; blood loss: competency to proficiency to mastery: -33%, 0%; conversion rate (competency to proficiency to mastery; -21%, -29%), whereas postoperative complications improved later (competency to proficiency to mastery: -25%, -41%). CONCLUSIONS: This review summarizes the highest evidence on learning curves in MILS taking into account different definitions and confounding factors. A standardized three-phase reporting of learning phases (competency, proficiency, mastery) is proposed and should be followed.

14.
Immunol Cell Biol ; 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38877291

RESUMEN

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system affecting predominantly adults. It is a complex disease associated with both environmental and genetic risk factors. Although over 230 risk single-nucleotide polymorphisms have been associated with MS, all are common human variants. The mechanisms by which they increase the risk of MS, however, remain elusive. We hypothesized that a complex genetic phenotype such as MS could be driven by coordinated expression of genes controlled by transcriptional regulatory networks. We, therefore, constructed a gene coexpression network from microarray expression analyses of five purified peripheral blood leukocyte subsets of 76 patients with relapsing remitting MS and 104 healthy controls. These analyses identified a major network (or module) of expressed genes associated with MS that play key roles in cell-mediated cytotoxicity which was downregulated in monocytes of patients with MS. Manipulation of the module gene expression was achieved in vitro through small interfering RNA gene knockdown of identified drivers. In a mouse model, network gene knockdown modulated the autoimmune inflammatory MS model disease-experimental autoimmune encephalomyelitis. This research implicates a cytotoxicity-associated gene network in myeloid cells in the pathogenesis of MS.

15.
Hepatology ; 78(4): 1092-1105, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37055018

RESUMEN

BACKGROUND AND AIMS: Chronic liver disease is a growing epidemic, leading to fibrosis and cirrhosis. TGF-ß is the pivotal profibrogenic cytokine that activates HSC, yet other molecules can modulate TGF-ß signaling during liver fibrosis. Expression of the axon guidance molecules semaphorins (SEMAs), which signal through plexins and neuropilins (NRPs), have been associated with liver fibrosis in HBV-induced chronic hepatitis. This study aims at determining their function in the regulation of HSCs. APPROACH AND RESULTS: We analyzed publicly available patient databases and liver biopsies. We used transgenic mice, in which genes are deleted only in activated HSCs to perform ex vivo analysis and animal models. SEMA3C is the most enriched member of the semaphorin family in liver samples from patients with cirrhosis. Higher expression of SEMA3C in patients with NASH, alcoholic hepatitis, or HBV-induced hepatitis discriminates those with a more profibrotic transcriptomic profile. SEMA3C expression is also elevated in different mouse models of liver fibrosis and in isolated HSCs on activation. In keeping with this, deletion of SEMA3C in activated HSCs reduces myofibroblast marker expression. Conversely, SEMA3C overexpression exacerbates TGF-ß-mediated myofibroblast activation, as shown by increased SMAD2 phosphorylation and target gene expression. Among SEMA3C receptors, only NRP2 expression is maintained on activation of isolated HSCs. Interestingly, lack of NRP2 in those cells reduces myofibroblast marker expression. Finally, deletion of either SEMA3C or NRP2, specifically in activated HSCs, reduces liver fibrosis in mice. CONCLUSION: SEMA3C is a novel marker for activated HSCs that plays a fundamental role in the acquisition of the myofibroblastic phenotype and liver fibrosis.


Asunto(s)
Células Estrelladas Hepáticas , Semaforinas , Animales , Humanos , Ratones , Células Estrelladas Hepáticas/metabolismo , Hígado/patología , Cirrosis Hepática/patología , Fosforilación , Semaforinas/genética , Semaforinas/metabolismo , Factor de Crecimiento Transformador beta/metabolismo
16.
Ann Surg Oncol ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38969858

RESUMEN

BACKGROUND: The risk for recurrence in patients with distal gastric cancer can be reduced by surgical radicality. However, dispute exists about the value of the proposed minimum proximal margin distance (PMD). Here, we assess the prognostic value of the safety distance between the proximal resection margin and the tumor. PATIENTS AND METHODS: This is a single-center cohort study of patients undergoing distal gastrectomy for gastric adenocarcinoma (2001-2021). Cohorts were defined by adequacy of the PMD according to the European Society for Medical Oncology (ESMO) guidelines (≥ 5 cm for intestinal and ≥ 8 cm for diffuse Laurén's subtypes). Overall survival (OS) and time to progression (TTP) were assessed by log-rank and multivariable Cox-regression analyses. RESULTS: Of 176 patients, 70 (39.8%) had a sufficient PMD. An adequate PMD was associated with cancer of the intestinal subtype (67% vs. 45%, p = 0.010). Estimated 5-year survival was 63% [95% confidence interval (CI) 51-78] and 62% (95% CI 53-73) for adequate and inadequate PMD, respectively. Overall, an adequate PMD was not prognostic for OS (HR 0.81, 95% CI 0.48-1.38) in the multivariable analysis. However, in patients with diffuse subtype, an adequate PMD was associated with improved oncological outcomes (median OS not reached versus 131 months, p = 0.038, median TTP not reached versus 88.0 months, p = 0.003). CONCLUSION: Patients with diffuse gastric cancer are at greater risk to undergo resection with an inadequate PMD, which in those patients is associated with worse oncological outcomes. For the intestinal subtype, there was no prognostic association with PMD, indicating that a distal gastrectomy with partial preservation of the gastric function may also be feasible in the setting where an extensive PMD is not achievable.

17.
Retina ; 44(1): 136-143, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37748439

RESUMEN

PURPOSE: To investigate eyes with polypoidal lesions associated with choroidal nevi, their multimodal imaging characteristics, and long clinical follow-up. METHODS: Multicenter, retrospective case series study of patients with polypoidal lesions overlying choroidal nevi. Demographic and clinical information were recorded. Multimodal imaging including color fundus photography, optical coherence tomography, optical coherence tomography angiography, fundus fluorescein angiography, indocyanine angiography, and A- and B-scan ultrasonography were analyzed for nevus and polypoidal lesion characteristics. RESULTS: Fourteen eyes (14 patients; mean age: 70.3 ± 6.7 years) with polypoidal lesions overlying choroidal nevi were included. The mean follow-up duration was 50.0 ± 27.9 months (range 12-108). All nevi were pigmented on color fundus photography, flat on ultrasonography with a mean basal diameter of 3.8 ± 0.4 mm. In all but one eye, optical coherence tomography showed a shallow irregular pigment epithelium detachment overlying the nevus. A total of 11/14 eyes (78.6%) had exudative activity, 9 eyes received intravitreal anti-vascular endothelial growth factor injections, and one eye required intravitreal anti-vascular endothelial growth factor combined with photodynamic therapy. Mean visual acuity was 20/32 at baseline and 20/50 at final visit. CONCLUSION: We present the largest known cohort of eyes with polypoidal lesions associated with choroidal nevi with up to 9 years follow-up. The exudative degree of the polypoidal lesion in this condition is variable and treatment decisions should be taken on an individual basis. We hypothesize that choroidal ischemia because of altered choroidal vasculature rather than Haller layer hyperpermeability plays a role in the formation of polypoidal lesions overlying nevi.


Asunto(s)
Enfermedades de la Coroides , Neoplasias de la Coroides , Nevo , Pólipos , Humanos , Persona de Mediana Edad , Anciano , Estudios Retrospectivos , Factores de Crecimiento Endotelial , Enfermedades de la Coroides/tratamiento farmacológico , Coroides/patología , Neoplasias de la Coroides/patología , Tomografía de Coherencia Óptica/métodos , Angiografía con Fluoresceína/métodos , Pólipos/tratamiento farmacológico , Inyecciones Intravítreas
18.
Appl Opt ; 63(6): 1618-1627, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38437377

RESUMEN

We developed a broadband two-layer anti-reflection (AR) coating for use on a sapphire half-wave plate (HWP) and an alumina infrared (IR) filter for the cosmic microwave background (CMB) polarimetry. Measuring the faint CMB B-mode signals requires maximizing the number of photons reaching the detectors and minimizing spurious polarization due to reflection with an off-axis incident angle. Sapphire and alumina have high refractive indices of 3.1 and are highly reflective without an AR coating. This paper presents the design, fabrication, quality control, and measured performance of an AR coating using thermally sprayed mullite and Duroid 5880LZ. This technology enables large optical elements with diameters of 600 mm. We also present a thermography-based nondestructive quality control technique, which is key to assuring good adhesion and preventing delamination when thermal cycling. We demonstrate the average reflectance of about 2.6% (0.9%) for two observing bands centered at 90/150 (220/280) GHz. At room temperature, the average transmittance of a 105 mm square test sample at 220/280 GHz is 83%, and it will increase to 90% at 100 K, attributed to reduced absorption losses. Therefore, our developed layering technique has proved effective for 220/280 GHz applications, particularly in addressing dielectric loss concerns. This AR coating technology has been deployed in the cryogenic HWP and IR filters of the Simons Array and the Simons observatory experiments and applies to future experiments such as CMB-S4.

19.
Langenbecks Arch Surg ; 409(1): 82, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38433154

RESUMEN

PURPOSE: Surgery offers exciting opportunities but comes with demanding challenges that require attention from both surgical program administrators and aspiring surgeons. The hashtag #NoTrainingTodayNoSurgeonsTomorrow on 𝕏 (previously Twitter) underscores the importance of ongoing training. Our scoping review identifies educational challenges and opportunities for the next generation of surgeons, analyzing existing studies and filling gaps in the literature. METHODS: Following the PRISMA guidelines, MEDLINE/PubMed was searched in February 2022, using the MeSH terms "surgeons/education," for articles in English or German on general, abdominal, thoracic, vascular, and hand surgery and traumatology targeting medical students, surgical residents, future surgeons, and fellows. RESULTS: The initial search yielded 1448 results. After a step-by-step evaluation process, 32 publications remained for complete review. Three main topics emerged: surgical innovations and training (n = 7), surgical culture and environment (n = 19), and mentoring (n = 6). The articles focusing on surgical innovations and training mainly described the incorporation of structured surgical training methods and program initiatives. Articles on surgical culture examined residents' burnout, well-being, and gender issues. Challenges faced by women, including implicit bias and sexual harassment, were highlighted. Regarding mentoring, mentees' needs, training challenges, and the qualities expected of both mentors and mentees were addressed. CONCLUSION: At a time of COVID-19-driven surgical innovations, the educational and working environment of the new generation of surgeons is changing. Robotic technology and other innovations require future surgeons to acquire additional technological and digital expertise. With regard to the cultural aspects of training, surgery needs to adapt curricula to meet the demands of the new generation of surgeons, but even more it has to transform its culture.


Asunto(s)
Curriculum , Cirujanos , Humanos , Exactitud de los Datos , Responsabilidad Social , Cirujanos/educación
20.
J Nerv Ment Dis ; 212(5): 251-254, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38198690

RESUMEN

ABSTRACT: A powerful correlation exists between the equilibrium of the sympathetic and parasympathetic nervous systems and heart rate variability (HRV). Thus, HRV is useful as a physiological index of both physical and emotional health; autonomic nervous system dysregulation, with a sympathetic predominance and a low HRV, has been associated with a variety of physical (cardiovascular, neurological) and psychiatric disorders. We used a validated algorithm of measuring the HRV (noninvasive, 2-minute approach) in new psychiatric outpatients in first author's private practice. The subjects had an initial measurement, followed by a 20-minute consultation with minimal supportive psychotherapy, followed by an exit measurement. The initial study spanned the "COVID months"; to control for this variable, an identical study was performed in 2023. There was a highly significant decrease in the sympathetic predominance in the test groups; no such trend was found in the control groups. A short psychiatry consultation may be sufficient to decrease patients' sympathetic hyperactivity and improve their well-being.


Asunto(s)
Sistema Nervioso Autónomo , Psiquiatras , Humanos , Sistema Nervioso Parasimpático , Frecuencia Cardíaca/fisiología
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