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The persistence and size of the Greenland Ice Sheet (GrIS) through the Pleistocene is uncertain. This is important because reconstructing changes in the GrIS determines its contribution to sea level rise during prior warm climate periods and informs future projections. To understand better the history of Greenland's ice, we analyzed glacial till collected in 1993 from below 3 km of ice at Summit, Greenland. The till contains plant fragments, wood, insect parts, fungi, and cosmogenic nuclides showing that the bed of the GrIS at Summit is a long-lived, stable land surface preserving a record of deposition, exposure, and interglacial ecosystems. Knowing that central Greenland was tundra-covered during the Pleistocene informs the understanding of Arctic biosphere response to deglaciation.
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Fósseis , Fungos , Camada de Gelo , Insetos , Plantas , Groenlândia , Camada de Gelo/microbiologia , Animais , Fungos/classificação , Plantas/microbiologia , Regiões Árticas , EcossistemaRESUMO
Chemotherapy-induced peripheral neuropathy (CIPN) is a disabling side effect of cancer chemotherapy that can often limit treatment options for cancer patients or have life-long neurodegenerative consequences that reduce the patient's quality of life. CIPN is caused by the detrimental actions of various chemotherapeutic agents on peripheral axons. Currently, there are no approved preventative measures or treatment options for CIPN, highlighting the need for the discovery of novel therapeutics and improving our understanding of disease mechanisms. In this study, we utilized human-induced pluripotent stem cell (hiPSC)-derived motor neurons as a platform to mimic axonal damage after treatment with vincristine, a chemotherapeutic used for the treatment of breast cancers, osteosarcomas, and leukemia. We screened a total of 1902 small molecules for neuroprotective properties in rescuing vincristine-induced axon growth deficits. From our primary screen, we identified 38 hit compounds that were subjected to secondary dose response screens. Six compounds showed favorable pharmacological profiles - AZD7762, A-674563, Blebbistatin, Glesatinib, KW-2449, and Pelitinib, all novel neuroprotectants against vincristine toxicity to neurons. In addition, four of these six compounds also showed efficacy against vincristine-induced growth arrest in human iPSC-derived sensory neurons. In this study, we utilized high-throughput screening of a large library of compounds in a therapeutically relevant assay. We identified several novel compounds that are efficacious in protecting different neuronal subtypes from the toxicity induced by a common chemotherapeutic agent, vincristine which could have therapeutic potential in the clinic.
Assuntos
Células-Tronco Pluripotentes Induzidas , Fármacos Neuroprotetores , Vincristina , Vincristina/farmacologia , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Fármacos Neuroprotetores/farmacologia , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/patologia , Neurônios Motores/metabolismo , Axônios/efeitos dos fármacos , Axônios/metabolismo , Axônios/patologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Células Cultivadas , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/patologia , Doenças do Sistema Nervoso Periférico/tratamento farmacológicoRESUMO
BACKGROUND: The Seattle Proportional Risk Model (SPRM) estimates the proportion of sudden cardiac death (SCD) in heart failure (HF) patients, identifying those most likely to benefit from implantable cardioverter-defibrillator (ICD) therapy (those with ≥50% estimated proportion of SCD). The GISSI-HF trial tested fish oil and rosuvastatin in HF patients. We used the SPRM to evaluate its accuracy in this cohort in predicting potential ICD benefit in patients with EF ≤50% and an SPRM-predicted proportion of SCD either ≥50% or <50%. METHODS: The SPRM was estimated in patients with EF ≤50% and in a logistic regression model comparing SCD with non-SCD. RESULTS: We evaluated 6,750 patients with EF ≤50%. There were 1,892 all-cause deaths, including 610 SCDs. Fifty percent of EF ≤35% patients and 43% with EF 36% to 50% had an SPRM of ≥50%. The SPRM (OR: 1.92, P < 0.0001) accurately predicted the risk of SCD vs non-SCD with an estimated proportion of SCD of 44% vs the observed proportion of 41% at 1 year. By traditional criteria for ICD implantation (EF ≤35%, NYHA class II or III), 64.5% of GISSI-HF patients would be eligible, with an estimated ICD benefit of 0.81. By SPRM >50%, 47.8% may be eligible, including 30.2% with EF >35%. GISSI-HF participants with EF ≤35% with SPRM ≥50% had an estimated ICD HR of 0.64, comparable to patients with EF 36% to 50% with SPRM ≥50% (HR: 0.65). CONCLUSIONS: The SPRM discriminated SCD vs non-SCD in GISSI-HF, both in patients with EF ≤35% and with EF 36% to 50%. The comparable estimated ICD benefit in patients with EF ≤35% and EF 36% to 50% supports the use of a proportional risk model for shared decision making with patients being considered for primary prevention ICD therapy.
Assuntos
Morte Súbita Cardíaca , Desfibriladores Implantáveis , Insuficiência Cardíaca , Humanos , Desfibriladores Implantáveis/estatística & dados numéricos , Masculino , Morte Súbita Cardíaca/prevenção & controle , Morte Súbita Cardíaca/epidemiologia , Feminino , Insuficiência Cardíaca/terapia , Idoso , Medição de Risco/métodos , Pessoa de Meia-Idade , Volume Sistólico/fisiologia , Fatores de Risco , Rosuvastatina Cálcica/uso terapêuticoRESUMO
ABSTRACT: Neisseria gonorrhoeae is a human obligate pathogen whose clinical expression of disease ranges from localized genital infection to involvement of extragenital sites such as the conjunctiva and throat. We describe the second case of a thyroglossal duct abscess due to N. gonorrhoeae, an uncommon complication of pharyngeal gonococcal infection. The fortuitous occurrence in the same individual of these 2 conditions that both exhibit an occult clinical presentation likely accounts for rarity of this infection. We discuss the pertinent gonococcal and host factors that underlie the clinical manifestations of this infection. A particular focus is the fundamental role that the binding of the gonococcal opacity-associated protein to the ubiquitous human carcinoembryonic cell adhesion molecule plays in the pathogenesis of pharyngeal gonorrhea.
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Gonorreia , Cisto Tireoglosso , Humanos , Genitália , Gonorreia/complicações , Gonorreia/diagnóstico , Neisseria gonorrhoeae , Faringe , Cisto Tireoglosso/cirurgiaRESUMO
The purpose of this study was to develop a measure of racial-ethnic-cultural (REC) belonging for Black, Indigenous, and other people of color (BIPOC). The iBelong Scale was designed to assess the multidimensional components of REC belonging across diverse BIPOC groups. The scale was constructed based on a grounded conceptual framework of REC belonging, and the initial pool of items received feedback from community members and content experts. Validation of the iBelong Scale comprised data from 808 BIPOC participants collected across three interrelated studies for the purposes of initial validation, construct validity, and test-retest reliability. In Study 1, an exploratory factor analysis yielded a 25-item scale with five factors: (a) Home, (b) Connection, (c) Authenticity, (d) REC Thriving, and (e) Self-Definition. Results from Study 2's confirmatory factor analysis indicated that the five-factor model was an acceptable fit of the data and the best fit among competing models. Measurement invariance was assessed, and results indicated that the iBelong Scale measures REC belonging similarly across differing BIPOC groups. The iBelong Scale was related to a range of measures in theoretically expected ways, including positive associations with general belonging, racial/ethnic identity, and general well-being, and negative associations with loneliness and REC nonbelonging. Findings from Study 3 indicated the test-retest reliability of the iBelong Scale over a 2-week period. Limitations of the studies and implications for research and practice are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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Etnicidade , Grupos Raciais , Humanos , Reprodutibilidade dos Testes , Análise Fatorial , Psicometria , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: Thalassaemia is one of the major health problems in Malaysia. With safe blood transfusion regime, the lifespan of patients with transfusion-dependent thalassaemia (TDT) has improved but at the cost of a higher risk of developing endocrine disorders. It is crucial for us to monitor the iron overload to prevent end organ damage. This study aims to evaluate the iron burden and prevalence of endocrinopathies in patients with TDT in Sarawak. MATERIALS AND METHODS: This retrospective cohort study was conducted between January 2020 to June 2020 in six government hospitals in Sarawak. A total of 89 patients with TDT, aged 10 years and above, were recruited. RESULTS: Out of the 89 patients, there were 54 males (60.7%) and 35 females (39.3%) with a median age of 21 years (range 10.0-65.0). Sixty-seven (75.3%) patients had betathalassaemia major and 15 (16.9%) patients had haemoglobin E beta-thalassaemia (HbE beta-thalassaemia), remaining seven patients had other genotypes. Thirty-one (34.8%) patients had mean serum ferritin 2500ng/ml and above, and 44 (66.6%) had liver iron concentration (LIC) ≥7mg/g. The prevalence of endocrine disorders in our cohort was 69.7%. The most common endocrinopathies were short stature (n=46, 51.7%), followed by hypogonadism (n=24, 26.9%), delayed puberty (n=23, 25.8%), hypothyroidism (n=10, 11.2%), diabetes mellitus (n=9, 10.1%), impaired glucose tolerance (n=6, 6.7%) and hypoparathyroidism (n=3, 3.3%). Endocrinopathies were significantly associated with age (p=0.01), age at initiating regular blood transfusion (p<0.01) and duration of regular blood transfusion (p<0.01). CONCLUSION: Our data shows that the development of endocrinopathies in TDT can be time dependent. Early detection of endocrine-related complications and prompt treatment with iron chelation therapy are important to improve morbidity and mortality. A multidisciplinary approach with good patient-doctor collaboration is the key to improving patient care in our settings.
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Transfusão de Sangue , Doenças do Sistema Endócrino , Sobrecarga de Ferro , Talassemia , Humanos , Masculino , Estudos Retrospectivos , Feminino , Malásia/epidemiologia , Adulto , Criança , Adolescente , Doenças do Sistema Endócrino/epidemiologia , Doenças do Sistema Endócrino/etiologia , Adulto Jovem , Talassemia/terapia , Talassemia/complicações , Talassemia/epidemiologia , Transfusão de Sangue/estatística & dados numéricos , Pessoa de Meia-Idade , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/epidemiologia , Prevalência , Idoso , Ferro/metabolismoRESUMO
Occupational heat stress (OHS) is an issue in healthcare facilities (HCFs) in the United Kingdom (UK). The aims of this study were to evaluate perceived levels of OHS during two seasons and its perceived consequences on healthcare professionals (HCPs) and to assess the efficacy of heat stress management (HSM) policies. An anonymous online survey was distributed to HCPs working in HCFs in the UK. The survey returned 1014 responses (87% women). Descriptive statistics and content analysis of survey data identified that OHS in HCFs is frequently experienced throughout the year and concerned most HCPs. Over 90% perceived OHS impairs their performance and 20% reported heat-related absenteeism. Awareness of HSM policies was poor and 73% deemed them not adequate. To help reduce the financial loss and impact on staff performance, health and well-being and patient safety, it is recommended that revisions and widespread dissemination of HSM policies are made.
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Pessoal de Saúde , Transtornos de Estresse por Calor , Estações do Ano , Humanos , Feminino , Reino Unido/epidemiologia , Masculino , Transtornos de Estresse por Calor/epidemiologia , Transtornos de Estresse por Calor/prevenção & controle , Pessoal de Saúde/psicologia , Adulto , Prevalência , Inquéritos e Questionários , Pessoa de Meia-Idade , Doenças Profissionais/epidemiologia , Absenteísmo , Instalações de SaúdeRESUMO
The study of evolution at the cellular level traditionally has focused on the evolution of metabolic pathways, endomembrane systems, and genomes, but there has been increasing interest in evolution of more complex cellular structures and behaviors, particularly in the eukaryotes. Ciliates have major advantages for such studies due to their easily visible surface patterning and their dramatic and complex behaviors that can be easily analyzed. Among the ciliates, the genus Stentor epitomizes the features that are useful for studying evolution: they are widespread in freshwater environments, easy to visualize because of their large size, and capable of complex behaviors such as learning, decision-making, and phototaxis. Here, we introduce the discovery of a new species within this genus: Stentor stipatus , so named for their distinctive dark brown aggregates. We present morphological, phylogenetic, ecological, and behavioral characterizations of these cells. The S. stipatus clade has a bootstrap value of 93 and is phylogenetically distinct from S. amethystinus , the closest related species which shares a sequence similarity of 98.9%. S. stipatus is capable of phototaxis and can also habituate more quickly than S. coeruleus , the Stentor species in which most habituation studies have previously been conducted. These findings expand our understanding of Stentor species diversity, natural history, and demonstrate common principles of complex behavior that are present in single-celled organisms.
RESUMO
The CRISPR-Cas9 genome editing system is used to induce mutations in genes of interest resulting in the loss of functional protein. A transgenic zebrafish α1-antitrypsin deficiency (AATD) model displays an unusual phenotype, in that it lacks the hepatic accumulation of the misfolding Z α1-antitrypsin (ZAAT) evident in human and mouse models. Here we describe the application of the CRISPR-Cas9 system to generate mutant zebrafish with defects in key proteostasis networks likely to be involved in the hepatic processing of ZAAT in this model. We describe the targeting of the atf6a and man1b1 genes as examples.
Assuntos
Perciformes , Proteostase , Humanos , Animais , Camundongos , Proteostase/genética , Sistemas CRISPR-Cas/genética , Edição de Genes , Peixe-Zebra/genética , Animais Geneticamente ModificadosRESUMO
Persistent junctional reciprocating tachycardia is a rare form of refractory atrioventricular reentrant tachycardia that accounts for <1% of supraventricular tachycardia in pediatrics. The accessory pathways are generally isolated with few reported underlying structural heart defects. We present a case of a five-month-old male with refractory tachyarrhythmia found to have cor triatriatum sinister, which to our knowledge, is the first reported case of these two rare anomalies coexisting.
Assuntos
Coração Triatriado , Humanos , Coração Triatriado/complicações , Coração Triatriado/cirurgia , Masculino , Lactente , Eletrocardiografia , Taquicardia Reciprocante/cirurgia , Taquicardia Reciprocante/complicações , Taquicardia Reciprocante/fisiopatologia , Taquicardia Ectópica de Junção/complicaçõesRESUMO
BACKGROUND: Management of newborns and healthcare workers (HCWs) exposed to congenital tuberculosis (TB) in the neonatal intensive care unit (NICU) has been reported rarely. AIM: To outline a contact investigation process for individuals exposed to congenital TB in the NICU and investigate nosocomial transmission. Additionally, to assess the efficacy and safety of window prophylaxis in exposed newborns. METHODS: A baby, born at a gestational age of 28 + 1 weeks, was diagnosed with isoniazid-resistant congenital TB on the 39th day of admission to the level IV NICU. Newborns and HCWs exposed cumulatively for ≥8 h underwent contact investigation and follow-up for a year. FINDINGS: Eighty-two newborns underwent contact investigation. All newborns displayed normal chest X-rays, and 42 hospitalized newborns tested negative for acid-fast bacilli stain and Xpert® MTB/RIF assay in their endotracheal sputum or gastric juices. Eighty received window prophylaxis: six of 75 on rifampin experienced mild adverse events, and none of the five on levofloxacin. After 12 weeks, five (6.1%) had a positive tuberculin skin test, all of whom had already received the Bacillus Calmette-Guérin vaccine and tested negative on TB interferon-gamma releasing assay. Of 119 exposed HCWs, three (2.5%) were diagnosed with latent TB infection and completed a four-month rifampin therapy. There was no active TB disease among exposed newborns and HCWs during a one-year follow-up. CONCLUSION: Timely diagnosis of congenital TB is crucial for minimizing transmission among exposed neonates and HCWs in the NICU setting. In cases of isoniazid-resistant index patients, even premature newborns may consider the use of rifampin or levofloxacin for window prophylaxis.
Assuntos
Antituberculosos , Infecção Hospitalar , Pessoal de Saúde , Unidades de Terapia Intensiva Neonatal , Isoniazida , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Isoniazida/uso terapêutico , Feminino , Masculino , Antituberculosos/uso terapêutico , Pessoal de Saúde/estatística & dados numéricos , Infecção Hospitalar/prevenção & controle , Rifampina/uso terapêutico , Adulto , Busca de Comunicante , Tuberculose/tratamento farmacológico , Tuberculose/prevenção & controle , Tuberculose/transmissãoRESUMO
In this study, we aimed to quantify the localised effects of mechanical loading (ML), low (20 µg/kg/day), moderate (40 µg/kg/day) or high (80 µg/kg/day) dosages of parathyroid hormone (PTH), and combined (PTHML) treatments on cortical bone adaptation in healthy 19-week old female C57BL/6 mice. To this end, we utilise a previously reported image analysis algorithm on µCT data of the mouse tibia published by Sugiyama et al. (2008) to measure changes in cortical area, marrow cavity area and local cortical thickness measures (ΔCt.Ar, ΔMa.Ar, ΔCt.Th respectively), evaluated at two cross-sections within the mouse tibia (proximal-middle (37 %) and middle (50 %)), and are compared to a superposed summation (P + M) of individual treatments to determine the effectiveness of combining treatments in vivo. ΔCt.Ar analysis revealed a non-linear, synergistic interactions between PTH and ML in the 37 % cross-section that saturates at higher PTH dosages, whereas the 50 % cross-section experiences an approximately linear, additive adaptation response. This coincided with an increase in ΔMa.Ar (indicating resorption of the endosteal surface), which was only counteracted by combined high dose PTH with ML in the middle cross-section. Regional analysis of ΔCt.Th changes reveal localised cortical thinning in response to low dose PTH treatment in the posteromedial region of the middle cross-section, signifying that PTH does not provide a homogeneous adaptation response around the cortical perimeter. We observe a synergistic response in the proximal-middle cross-section, with regions of compressive strain experiencing the greatest adaptation response to PTHML treatments, (peak ΔCt.Th of 189.32, 213.78 and 239.30 µm for low, moderate and high PTHML groups respectively). In contrast, PTHML treatments in the middle cross-section show a similar response to the superposed P + M group, with the exception of the combined high dose PTHML treatment which shows a synergistic interaction. These analyses suggest that, in mice, adding mechanical loading to PTH treatments leads to region specific bone responses; synergism of PTHML is only achieved in some regions experiencing high loading, while other regions respond additively to this combined treatment.
Assuntos
Hormônio Paratireóideo , Tíbia , Camundongos , Feminino , Animais , Hormônio Paratireóideo/farmacologia , Tíbia/fisiologia , Camundongos Endogâmicos C57BL , Osso e Ossos , Osso Cortical/diagnóstico por imagem , Modelos Animais de DoençasRESUMO
Site-directed insertion is a powerful approach for generating mutant alleles, but low efficiency and the need for customisation for each target has limited its application. To overcome this, we developed a highly efficient targeted insertional mutagenesis system, CRIMP, and an associated plasmid toolkit, CRIMPkit, that disrupts native gene expression by inducing complete transcriptional termination, generating null mutant alleles without inducing genetic compensation. The protocol results in a high frequency of integration events and can generate very early targeted insertions, during the first cell division, producing embryos with expression in one or both halves of the body plan. Fluorescent readout of integration events facilitates selection of successfully mutagenized fish and, subsequently, visual identification of heterozygous and mutant animals. Together, these advances greatly improve the efficacy of generating and studying mutant lines. The CRIMPkit contains 24 ready-to-use plasmid vectors to allow easy and complete mutagenesis of any gene in any reading frame without requiring custom sequences, modification, or subcloning.
Assuntos
Sistemas CRISPR-Cas , Mutagênese Insercional , Plasmídeos , Peixe-Zebra , Mutagênese Insercional/métodos , Animais , Plasmídeos/genética , Peixe-Zebra/genética , Vetores Genéticos/genética , Edição de Genes/métodos , AlelosRESUMO
BACKGROUND: Colorectal cancer (CRC) incidence and mortality rates have been increasing among young patients (YP), for uncertain reasons. It is unclear whether YP have a distinct tumor biology or merit a different treatment approach to older patients (OP). METHODS: We reviewed prospectively collected data from consecutive patients with metastatic CRC (MCRC) enrolled in the multi-site Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) Australian registry. Clinicopathological features, treatment and survival outcomes were compared between YP (<50 years) and OP (≥50 years). RESULTS: Of 3692 patients diagnosed August 2009 - March 2023, 14 % (513) were YP. YP were more likely than OP to be female (52% vs. 40 %, P < 0.0001), have ECOG performance status 0-1 (94% vs. 81 %, P < 0.0001), to have a left-sided primary (72% vs. 63 %, P = 0.0008) and to have fewer comorbidities (90% vs. 60 % Charleston score 0, P < 0.0001). There were no differences in the available molecular status, which was more complete in YP. YP were more likely to have de novo metastatic disease (71% vs. 57 %, P < 0.0001). YP were more likely to undergo curative hepatic resection (27% vs. 17 %, P < 0.0001), to receive any chemotherapy (93% vs. 78 % (P < 0.0001), and to receive 3+ lines of chemotherapy (30% vs. 24 % (P < 0.0034)). Median first-line progression free survival (10.2 versus 10.6 months) was similar for YP vs OP, but overall survival (32.1 versus 25.4 months, HR = 0.745, P < 0.0001) was longer in YP. CONCLUSION: Known prognostic variables mostly favored YP versus OP with newly diagnosed mCRC, who were also more heavily treated. Consistent with this, overall survival outcomes were improved. This data does not support that CRC in YP represent a distinct subset of mCRC patients, or that a modified treatment approach is warranted.
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Skeletal muscle wasting results from numerous pathological conditions affecting both the musculoskeletal and nervous systems. A unifying feature of these pathologies is the upregulation of members of the E3 ubiquitin ligase family, resulting in increased proteolytic degradation of target proteins. Despite the critical role of E3 ubiquitin ligases in regulating muscle mass, the specific proteins they target for degradation and the mechanisms by which they regulate skeletal muscle homeostasis remain ill-defined. Here, using zebrafish loss-of-function models combined with in vivo cell biology and proteomic approaches, we reveal a role of atrogin-1 in regulating the levels of the endoplasmic reticulum chaperone BiP. Loss of atrogin-1 resulted in an accumulation of BiP, leading to impaired mitochondrial dynamics and a subsequent loss in muscle fiber integrity. We further implicated a disruption in atrogin-1-mediated BiP regulation in the pathogenesis of Duchenne muscular dystrophy. We revealed that BiP was not only upregulated in Duchenne muscular dystrophy, but its inhibition using pharmacological strategies, or by upregulating atrogin-1, significantly ameliorated pathology in a zebrafish model of Duchenne muscular dystrophy. Collectively, our data implicate atrogin-1 and BiP in the pathogenesis of Duchenne muscular dystrophy and highlight atrogin-1's essential role in maintaining muscle homeostasis.
Assuntos
Modelos Animais de Doenças , Chaperona BiP do Retículo Endoplasmático , Homeostase , Proteínas Musculares , Músculo Esquelético , Distrofia Muscular de Duchenne , Proteínas Ligases SKP Culina F-Box , Peixe-Zebra , Animais , Proteínas Ligases SKP Culina F-Box/metabolismo , Proteínas Ligases SKP Culina F-Box/genética , Proteínas Musculares/metabolismo , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patologia , Distrofia Muscular de Duchenne/genética , Humanos , Chaperona BiP do Retículo Endoplasmático/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Retículo Endoplasmático/metabolismo , Dinâmica MitocondrialRESUMO
Chemotherapy-induced peripheral neuropathy (CIPN) is a disabling side effect of cancer chemotherapy that can often limit treatment options for cancer patients or have life-long neurodegenerative consequences that reduce the patient's quality of life. CIPN is caused by the detrimental actions of various chemotherapeutic agents on peripheral axons. Currently, there are no approved preventative measures or treatment options for CIPN, highlighting the need for the discovery of novel therapeutics and improving our understanding of disease mechanisms. In this study, we utilized human-induced pluripotent stem cell (hiPSC)-derived motor neurons as a platform to mimic axonal damage after treatment with vincristine, a chemotherapeutic used for the treatment of breast cancers, osteosarcomas, and leukemia. We screened a total of 1902 small molecules for neuroprotective properties in rescuing vincristine-induced axon growth deficits. From our primary screen, we identified 38 hit compounds that were subjected to secondary dose response screens. Six compounds showed favorable pharmacological profiles - AZD7762, A-674563, Blebbistatin, Glesatinib, KW-2449, and Pelitinib, all novel neuroprotectants against vincristine toxicity to neurons. In addition, four of these six compounds also showed efficacy against vincristine-induced growth arrest in human iPSC-derived sensory neurons. In this study, we utilized high-throughput screening of a large library of compounds in a therapeutically relevant assay. We identified several novel compounds that are efficacious in protecting different neuronal subtypes from the toxicity induced by a common chemotherapeutic agent, vincristine which could have therapeutic potential in the clinic.
RESUMO
We recently reported that resistance to PD-1 blockade in a refractory lung cancer-derived model involved increased collagen deposition and the collagen-binding inhibitory receptor leukocyte-associated immunoglobulin-like receptor 1 (LAIR1). Thus, we hypothesized that LAIR1 and collagen cooperated to suppress therapeutic response. In this study, we report that LAIR1 is associated with tumor stroma and is highly expressed by intratumoral myeloid cells in both human tumors and mouse models of cancer. Stroma-associated myeloid cells exhibit a suppressive phenotype and correlate with LAIR1 expression in human cancer. NGM438, a novel humanized LAIR1 antagonist mAb, elicits myeloid inflammation and allogeneic T-cell responses by binding to LAIR1 and blocking collagen engagement. Furthermore, a mouse-reactive NGM438 surrogate antibody sensitized refractory KP mouse lung tumors to anti-PD-1 therapy and resulted in increased intratumoral CD8+ T-cell content and inflammatory gene expression. These data place LAIR1 at the intersection of stroma and suppressive myeloid cells and support the notion that blockade of the LAIR1/collagen axis can potentially address resistance to checkpoint inhibitor therapy in the clinic.
Assuntos
Antineoplásicos , Colágeno , Inibidores de Checkpoint Imunológico , Receptores Imunológicos , Animais , Feminino , Humanos , Camundongos , Linhagem Celular Tumoral , Colágeno/metabolismo , Modelos Animais de Doenças , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Neoplasias/metabolismo , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptores Imunológicos/antagonistas & inibidores , Receptores Imunológicos/metabolismo , Antineoplásicos/uso terapêuticoRESUMO
Troponin I (TnI) regulates thin filament activation and muscle contraction. Two isoforms, TnI-fast (TNNI2) and TnI-slow (TNNI1), are predominantly expressed in fast- and slow-twitch myofibers, respectively. TNNI2 variants are a rare cause of arthrogryposis, whereas TNNI1 variants have not been conclusively established to cause skeletal myopathy. We identified recessive loss-of-function TNNI1 variants as well as dominant gain-of-function TNNI1 variants as a cause of muscle disease, each with distinct physiological consequences and disease mechanisms. We identified three families with biallelic TNNI1 variants (F1: p.R14H/c.190-9G>A, F2 and F3: homozygous p.R14C), resulting in loss of function, manifesting with early-onset progressive muscle weakness and rod formation on histology. We also identified two families with a dominantly acting heterozygous TNNI1 variant (F4: p.R174Q and F5: p.K176del), resulting in gain of function, manifesting with muscle cramping, myalgias, and rod formation in F5. In zebrafish, TnI proteins with either of the missense variants (p.R14H; p.R174Q) incorporated into thin filaments. Molecular dynamics simulations suggested that the loss-of-function p.R14H variant decouples TnI from TnC, which was supported by functional studies showing a reduced force response of sarcomeres to submaximal [Ca2+] in patient myofibers. This contractile deficit could be reversed by a slow skeletal muscle troponin activator. In contrast, patient myofibers with the gain-of-function p.R174Q variant showed an increased force to submaximal [Ca2+], which was reversed by the small-molecule drug mavacamten. Our findings demonstrated that TNNI1 variants can cause muscle disease with variant-specific pathomechanisms, manifesting as either a hypo- or a hypercontractile phenotype, suggesting rational therapeutic strategies for each mechanism.
Assuntos
Doenças Musculares , Sarcômeros , Animais , Humanos , Cálcio/metabolismo , Contração Muscular , Músculo Esquelético/metabolismo , Doenças Musculares/genética , Sarcômeros/metabolismo , Troponina I/genética , Troponina I/metabolismo , Peixe-Zebra/metabolismoRESUMO
Solid tumors are dense three-dimensional (3D) multicellular structures that enable efficient receptor-ligand trans interactions via close cell-cell contact. Immunoglobulin-like transcript (ILT)2 and ILT4 are related immune-suppressive receptors that play a role in the inhibition of myeloid cells within the tumor microenvironment. The relative contribution of ILT2 and ILT4 to immune inhibition in the context of solid tumor tissue has not been fully explored. We present evidence that both ILT2 and ILT4 contribute to myeloid inhibition. We found that although ILT2 inhibits myeloid cell activation in the context of trans-engagement by MHC-I, ILT4 efficiently inhibits myeloid cells in the presence of either cis- or trans-engagement. In a 3D spheroid tumor model, dual ILT2/ILT4 blockade was required for the optimal activation of myeloid cells, including the secretion of CXCL9 and CCL5, upregulation of CD86 on dendritic cells, and downregulation of CD163 on macrophages. Humanized mouse tumor models showed increased immune activation and cytolytic T-cell activity with combined ILT2 and ILT4 blockade, including evidence of the generation of immune niches, which have been shown to correlate with clinical response to immune-checkpoint blockade. In a human tumor explant histoculture system, dual ILT2/ILT4 blockade increased CXCL9 secretion, downregulated CD163 expression, and increased the expression of M1 macrophage, IFNγ, and cytolytic T-cell gene signatures. Thus, we have revealed distinct contributions of ILT2 and ILT4 to myeloid cell biology and provide proof-of-concept data supporting the combined blockade of ILT2 and ILT4 to therapeutically induce optimal myeloid cell reprogramming in the tumor microenvironment.
Assuntos
Antígenos CD , Receptor B1 de Leucócitos Semelhante a Imunoglobulina , Glicoproteínas de Membrana , Células Mieloides , Receptores Imunológicos , Microambiente Tumoral , Receptores Imunológicos/metabolismo , Animais , Humanos , Camundongos , Microambiente Tumoral/imunologia , Receptor B1 de Leucócitos Semelhante a Imunoglobulina/metabolismo , Células Mieloides/imunologia , Células Mieloides/metabolismo , Glicoproteínas de Membrana/metabolismo , Linhagem Celular Tumoral , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismoRESUMO
The generalizability of findings from Clinical Trials (CTs) investigating lymphedema treatment modalities requires an accurate representation of the target population. This study aims to evaluate racial and ethnic reporting and representation in lymphedema CTs. A comprehensive systematic literature search was conducted during May 2023 using multiple databases, following the PRISMA guidelines. All CTs published from 2018 to 2023 were included. A total of 84 articles were included in this review, from which 6,546 participants were included in the analysis. Seventy-four (88.1%) articles addressed secondary lymphedema, of which 60 (81.1%) were related to breast cancer. Only 12 (13%) of CTs reported at some extend race or ethnicity. Of these, five (41.6%) reported race and two (16.6%) reported ethnicity according to FDA guidelines. White race had the highest pooled prevalence (80%; 95% CI 72-86%; I2=90%), followed by Black (7%; 95% CI 2- 15%; I2= 94.3%) and Asian (4%; 95% CI 1-8%; I2= 89.9%). In studies reporting ethnicity, participants were predominantly non-Hispanic (92.1%; 95% CI 90 - 94%). There is an underreporting and underrepresentation of racial and ethnic minorities among lymphedema CTs, limiting their generalizability. It is imperative to future development of strategies to enhance diversity in the study sample.