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1.
Proc Natl Acad Sci U S A ; 119(29): e2204369119, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35858362

RESUMO

The biological carbon pump (BCP) stores ∼1,700 Pg C from the atmosphere in the ocean interior, but the magnitude and direction of future changes in carbon sequestration by the BCP are uncertain. We quantify global trends in export production, sinking organic carbon fluxes, and sequestered carbon in the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) future projections, finding a consistent 19 to 48 Pg C increase in carbon sequestration over the 21st century for the SSP3-7.0 scenario, equivalent to 5 to 17% of the total increase of carbon in the ocean by 2100. This is in contrast to a global decrease in export production of -0.15 to -1.44 Pg C y-1. However, there is significant uncertainty in the modeled future fluxes of organic carbon to the deep ocean associated with a range of different processes resolved across models. We demonstrate that organic carbon fluxes at 1,000 m are a good predictor of long-term carbon sequestration and suggest this is an important metric of the BCP that should be prioritized in future model studies.


Assuntos
Sequestro de Carbono , Carbono , Ecossistema , Atmosfera/química , Carbono/análise , Modelos Teóricos , Oceanos e Mares , Incerteza
3.
Biochem Biophys Res Commun ; 604: 137-143, 2022 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-35303680

RESUMO

Rho kinase (ROCK) is implicated in the development of pulmonary arterial hypertension (PAH) in which abnormal pulmonary vascular smooth muscle (VSM) contractility and remodeling lead to right heart failure. Pharmacologic ROCK inhibitors block experimental pulmonary hypertension (PH) development in rodents but can have off-target effects and do not distinguish between the two ROCK forms, ROCK1 and ROCK2, encoded by separate genes. An earlier study using gene knock out (KO) in mice indicated that VSM ROCK2 is required for experimental PH development, but the role of ROCK1 is not well understood. Here we investigated the in vivo role of ROCK1 in PH development by generating a VSM-targeted homozygous ROCK1 gene KO mouse strain. Adult control mice exposed to Sugen5416 (Su)/hypoxia treatment to induce PH had significantly increased right ventricular systolic pressures (RVSP) and RV hypertrophy versus normoxic controls. In contrast, Su/hypoxia-exposed VSM ROCK1 KO mice did not exhibit significant RVSP elevation, and RV hypertrophy was blunted. Su/hypoxia-induced pulmonary small vessel muscularization was similarly elevated in both control and VSM ROCK1 KO animals. siRNA-mediated ROCK1 knock-down (KD) in human PAH pulmonary arterial SM cells (PASMC) did not affect cell growth. However, ROCK1 KD led to reduced AKT and MYPT1 signaling in serotonin-treated PAH PASMC. The findings suggest that like VSM ROCK2, VSM ROCK1 actively contributes to PH development, but in distinction acts via nonproliferative pathways to promote hypoxemia, and thus may be a distinct therapeutic target in PH.


Assuntos
Hipertensão Arterial Pulmonar , Quinases Associadas a rho , Animais , Hipertrofia Ventricular Direita/genética , Hipóxia/complicações , Camundongos , Camundongos Knockout , Músculo Liso Vascular/enzimologia , Miócitos de Músculo Liso/metabolismo , Hipertensão Arterial Pulmonar/genética , Artéria Pulmonar/metabolismo , Quinases Associadas a rho/genética , Quinases Associadas a rho/metabolismo , Quinases Associadas a rho/fisiologia
4.
Glob Chang Biol ; 28(3): 1063-1076, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34706138

RESUMO

Planktonic foraminifera are one of the primary calcifiers in the modern ocean, contributing 23%-56% of total global pelagic carbonate production. However, a mechanistic understanding of how physiology and environmental conditions control their abundance and distribution is lacking, hindering the projection of the impact of future climate change. This understanding is important, not only for ecosystem dynamics, but also for marine carbon cycling because of foraminifera's key role in carbonate production. Here we present and apply a global trait-based ecosystem model of non-spinose planktonic foraminifera ('ForamEcoGEnIE') to assess their ecology and global distribution under future climate change. ForamEcoGEnIE considers the traits of calcium carbonate production, shell size, and foraging. It captures the main characteristic of biogeographical patterns of non-spinose species - with maximum biomass concentrations found in mid- to high-latitude waters and upwelling areas. The model also reproduces the magnitude of global carbonate production relatively well, although the foraminifera standing stock is systematically overestimated. In response to future scenarios of rising atmospheric CO2 (RCP6 and RCP8.5), on a regional scale, the modelled foraminifera biomass and export flux increases in the subpolar regions of the North Atlantic and the Southern Ocean while it decreases everywhere else. In the absence of adaptation, the biomass decline in the low-latitude South Pacific suggests extirpation. The model projects a global average loss in non-spinose foraminifera biomass between 8% (RCP6) and 11% (RCP8.5) by 2050 and between 14% and 18% by 2100 as a response to ocean warming and associated changes in primary production and ecological dynamics. Global calcium carbonate flux associated with non-spinose foraminifera declines by 13%-18% by 2100. That decline can slow down the ocean carbonate pump and create short-term positive feedback on rising atmospheric pCO2 .


Assuntos
Foraminíferos , Ciclo do Carbono , Mudança Climática , Ecossistema , Foraminíferos/fisiologia , Oceanos e Mares , Plâncton/fisiologia
5.
Horm Behav ; 140: 105122, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35101702

RESUMO

Brain-derived 17ß-estradiol (E2) confers rapid effects on neural activity. The tubular striatum (TuS, also called the olfactory tubercle) is both capable of local E2 synthesis due to its abundant expression of aromatase and is a critical locus for odor-guided motivated behavior and odor hedonics. TuS neurons also contain mRNA for estrogen receptors α, ß, and the G protein-coupled estrogen receptor. We demonstrate here that mRNA for estrogen receptors appears to be expressed upon TuS dopamine 1 receptor-expressing neurons, suggesting that E2 may play a neuromodulatory role in circuits which are important for motivated behavior. Therefore, we reasoned that E2 in the TuS may influence attraction to urinary odors which are highly attractive. Using whole-body plethysmography, we examined odor-evoked high-frequency sniffing as a measure of odor attaction. Bilateral infusion of the aromatase inhibitor letrozole into the TuS of gonadectomized female adult mice induced a resistance to habituation over successive trials in their investigatory sniffing for female mouse urinary odors, indicative of an enhanced attraction. All males displayed resistance to habituation for female urinary odors, indicative of enhanced attraction that is independent from E2 manipulation. Letrozole's effects were not due to group differences in basal respiration, nor changes in the ability to detect or discriminate between odors (both monomolecular odorants and urinary odors). Therefore, de novo E2 synthesis in the TuS impacts females' but not males' attraction to female urinary odors, suggesting a sex-specific influence of E2 in odor hedonics.


Assuntos
Estradiol , Odorantes , Animais , Encéfalo , Estradiol/farmacologia , Estrogênios/farmacologia , Feminino , Masculino , Camundongos , Neostriado , Olfato
6.
Br J Haematol ; 192(5): 853-868, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32656799

RESUMO

Second-generation immunomodulatory agents, such as lenalidomide, have a more favourable side-effect profile than the first-generation thalidomide, but their optimum combination and duration for patients with newly diagnosed transplant-ineligible myeloma (ND-TNE-MM) has not been defined. The most appropriate delivery and dosing regimens of these therapies for patients at advanced age and frailty status is also unclear. The Myeloma XI study compared cyclophosphamide, thalidomide and dexamethasone (CTDa) to cyclophosphamide, lenalidomide and dexamethasone (CRDa) as induction therapy, followed by a maintenance randomisation between ongoing therapy with lenalidomide or observation for patients with ND-TNE-MM. CRDa deepened response but did not improve progression-free (PFS) or overall survival (OS) compared to CTDa. However, analysis by age group highlighted significant differences in tolerability in older, frailer patients that may have limited treatment delivery and impacted outcome. Deeper responses and PFS and OS benefits with CRDa over CTDs were seen in patients aged ≤70 years, with an increase in toxicity and discontinuation observed in older patients. Our results highlight the importance of considering age and frailty in the approach to therapy for patients with ND-TNE-MM, highlighting the need for prospective validation of frailty adapted therapy approaches, which may improve outcomes by tailoring treatment to the individual.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Fatores Imunológicos/uso terapêutico , Imunomodulação , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Bortezomib/administração & dosagem , Quimioterapia de Consolidação , Ciclofosfamida/administração & dosagem , Dexametasona/administração & dosagem , Feminino , Humanos , Estimativa de Kaplan-Meier , Lenalidomida/administração & dosagem , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Indução de Remissão , Talidomida/administração & dosagem , Resultado do Tratamento
7.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203295

RESUMO

A key feature of pulmonary arterial hypertension (PAH) is the hyperplastic proliferation exhibited by the vascular smooth muscle cells from patients (HPASMC). The growth inducers FOXM1 and PLK1 are highly upregulated in these cells. The mechanism by which these two proteins direct aberrant growth in these cells is not clear. Herein, we identify cyclin-dependent kinase 1 (CDK1), also termed cell division cycle protein 2 (CDC2), as having a primary role in promoting progress of the cell cycle leading to proliferation in HPASMC. HPASMC obtained from PAH patients and pulmonary arteries from Sugen/hypoxia rats were investigated for their expression of CDC2. Protein levels of CDC2 were much higher in PAH than in cells from normal donors. Knocking down FOXM1 or PLK1 protein expression with siRNA or pharmacological inhibitors lowered the cellular expression of CDC2 considerably. However, knockdown of CDC2 with siRNA or inhibiting its activity with RO-3306 did not reduce the protein expression of FOXM1 or PLK1. Expression of CDC2 and FOXM1 reached its maximum at G1/S, while PLK1 reached its maximum at G2/M phase of the cell cycle. The expression of other CDKs such as CDK2, CDK4, CDK6, CDK7, and CDK9 did not change in PAH HPASMC. Moreover, inhibition via Wee1 inhibitor adavosertib or siRNAs targeting Wee1, Myt1, CDC25A, CDC25B, or CDC25C led to dramatic decreases in CDC2 protein expression. Lastly, we found CDC2 expression at the RNA and protein level to be upregulated in pulmonary arteries during disease progression Sugen/hypoxia rats. In sum, our present results illustrate that the increased expression of FOXM1 and PLK1 in PAH leads directly to increased expression of CDC2 resulting in potentiated growth hyperactivity of PASMC from patients with pulmonary hypertension. Our results further suggest that the regulation of CDC2, or associated regulatory proteins, will prove beneficial in the treatment of this disease.


Assuntos
Proteína Quinase CDC2/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteína Forkhead Box M1/metabolismo , Músculo Liso Vascular/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Proteína Quinase CDC2/genética , Ciclo Celular/genética , Ciclo Celular/fisiologia , Proteínas de Ciclo Celular/genética , Proliferação de Células/fisiologia , Proteína Forkhead Box M1/genética , Humanos , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Hipertensão Arterial Pulmonar/genética , Hipertensão Arterial Pulmonar/metabolismo , Ratos , Ratos Sprague-Dawley , Remodelação Vascular/genética , Remodelação Vascular/fisiologia , Quinase 1 Polo-Like
8.
J Cell Sci ; 127(Pt 13): 2811-7, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24794496

RESUMO

Defects in SLX4, a scaffold for DNA repair nucleases, result in Fanconi anemia (FA), due to the defective repair of inter-strand DNA crosslinks (ICLs). Some FA patients have an SLX4 deletion removing two tandem UBZ4-type ubiquitin-binding domains that are implicated in protein recruitment to sites of DNA damage. Here, we show that human SLX4 is recruited to sites of ICL induction but that the UBZ-deleted form of SLX4 in cells from FA patients is not. SLX4 recruitment does not require either the ubiquitylation of FANCD2 or the E3 ligases RNF8, RAD18 and BRCA1. We show that the first (UBZ-1) but not the second UBZ domain of SLX4 binds to ubiquitin polymers, with a preference for K63-linked chains. Furthermore, UBZ-1 is required for SLX4 recruitment to ICL sites and for efficient ICL repair in murine fibroblasts. The SLX4 UBZ-2 domain does not bind to ubiquitin in vitro or contribute to ICL repair, but it is required for the resolution of Holliday junctions in vivo. These data shed light on SLX4 recruitment, and they point to the existence of currently unidentified ubiquitylated ligands and E3 ligases that are crucial for ICL repair.


Assuntos
Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Recombinases/genética , Ubiquitina/metabolismo , Animais , Sítios de Ligação , DNA/genética , DNA/metabolismo , Reparo do DNA , Humanos , Camundongos , Estrutura Terciária de Proteína , Recombinases/metabolismo
9.
Opt Express ; 24(25): 29001-29008, 2016 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-27958565

RESUMO

A new approach has been proposed to determine ocean subsurface particulate backscattering coefficient bbp from CALIOP 30° off-nadir lidar measurements. The new method also provides estimates of the particle volume scattering function at the 180° scattering angle. The CALIOP based layer-integrated lidar backscatter and particulate backscattering coefficients are compared with the results obtained from MODIS ocean color measurements. The comparison analysis shows that ocean subsurface lidar backscatter and particulate backscattering coefficient bbp can be accurately obtained from CALIOP lidar measurements, thereby supporting the use of space-borne lidar measurements for ocean subsurface studies.

10.
Br J Neurosurg ; 30(6): 654-657, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27100665

RESUMO

PURPOSE: Nanocrystalline hydroxyapatite (nHA) cages have emerged as a new alternative to carbon fiber or polyether ether ketone (PEEK) devices to promote intervertebral fusion. No evidence has been published to date regarding rates of fusion for these devices after anterior cervical discectomy and fusion (ACDF). METHODS: Eight patients underwent one- or two-level ACDF with nHA intervertebral cages (Nanoss®-Cervical, Pioneer® Surgical Technology, Inc., Marquette, MI). Radiographs, neck disability index (NDI) and visual analog scores (VAS) for pain were taken preoperatively and at a minimum of 19 months postoperatively. RESULTS: At an average follow-up of 21 months, all eight patients (100%) achieved fusion as assessed by plain radiographs. Reduction in preoperative symptomology was comparable to previously published data with a mean reduction of neck VAS of 3, arm VAS of 6 and NDI reduced by 27%. Radiographs showed clear evidence of bridging bone. CONCLUSIONS: This series provides evidence that nHA intervertebral cages can successfully promote fusion after ACDF and may provide an alternative to carbon fiber and PEEK cages.


Assuntos
Materiais Biocompatíveis , Discotomia/métodos , Durapatita , Fixadores Internos , Fusão Vertebral/métodos , Adulto , Benzofenonas , Avaliação da Deficiência , Feminino , Seguimentos , Humanos , Cetonas , Masculino , Pessoa de Meia-Idade , Cervicalgia/diagnóstico por imagem , Cervicalgia/cirurgia , Medição da Dor , Polietilenoglicóis , Polímeros , Resultado do Tratamento
11.
J Cell Biochem ; 116(3): 386-97, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25290246

RESUMO

Pulmonary arterial hypertension (PAH) is characterized by increased pulmonary vascular smooth muscle contraction and proliferation. Here, we analyze genome-wide mRNA expression in human pulmonary arterial smooth muscle cells (HPASMC) isolated from three control, three hereditary (HPAH), and three idiopathic PAH (IPAH) subjects using the Affymetrix Human Gene ST 1.0 chip. The microarray analysis reveals the expression of 537 genes in HPAH and 1024 genes in IPAH changed compared with control HPASMC. Among those genes, 227 genes show similar directionality of expression in both HPAH and IPAH HPASMC. Ingenuity™ Pathway Analysis (IPA) suggests that many of those genes are involved in cellular growth/proliferation and cell cycle regulation and that signaling pathways such as the mitotic activators, polo-like kinases, ATM signaling are activated under PAH conditions. Furthermore, the analysis demonstrates downregulated mRNA expression of certain vasoactive receptors such as bradykinin receptor B2 (BKB2R). Using real time PCR, we verified the downregulated BKB2R expression in the PAH cells. Bradykinin-stimulated calcium influx is also decreased in PAH PASMC. IPA also identified transcriptional factors such p53 and Rb as downregulated, and FoxM1 and Myc as upregulated in both HPAH and IPAH HPASMC. The decreased level of phospho-p53 in PAH cells was confirmed with a phospho-protein array; and we experimentally show a dysregulated proliferation of both HPAH and IPAH PASMC. Together, the microarray experiments and bioinformatics analysis highlight an aberrant proliferation and cell cycle regulation in HPASMC from PAH subjects. These newly identified pathways may provide new targets for the treatment of both hereditary and idiopathic PAH.


Assuntos
Hipertensão Pulmonar Primária Familiar/genética , Miócitos de Músculo Liso/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Artéria Pulmonar/patologia , Transdução de Sinais/genética , Anticorpos Fosfo-Específicos/metabolismo , Estudos de Casos e Controles , Ciclo Celular/genética , Proliferação de Células , Células Cultivadas , Hipertensão Pulmonar Primária Familiar/patologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Miócitos de Músculo Liso/patologia , Fenótipo , Fosforilação , Análise de Componente Principal , Artéria Pulmonar/metabolismo , Artéria Pulmonar/fisiopatologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 1 de Angiotensina/metabolismo , Receptor B2 da Bradicinina/genética , Receptor B2 da Bradicinina/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
12.
N C Med J ; 76(1): 41-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25621481

RESUMO

Down East Partnership for Children is committed to launching every child in Nash and Edgecombe counties as a healthy, lifelong learner by the end of the 3rd grade. Our 20-year journey has leveraged various resources and brought together education and health to make the greatest impact on economic success.


Assuntos
Serviços de Saúde da Criança , Proteção da Criança , Intervenção Educacional Precoce , Criança , Pré-Escolar , Indicadores Básicos de Saúde , Humanos , Lactente , Recém-Nascido , North Carolina
13.
Blood Adv ; 8(5): 1209-1219, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38127279

RESUMO

ABSTRACT: During the COVID-19 pandemic, ibrutinib with or without rituximab was approved in England for initial treatment of mantle cell lymphoma (MCL) instead of immunochemotherapy. Because limited data are available in this setting, we conducted an observational cohort study evaluating safety and efficacy. Adults receiving ibrutinib with or without rituximab for untreated MCL were evaluated for treatment toxicity, response, and survival, including outcomes in high-risk MCL (TP53 mutation/deletion/p53 overexpression, blastoid/pleomorphic, or Ki67 ≥ 30%). A total of 149 patients from 43 participating centers were enrolled: 74.1% male, median age 75 years, 75.2% Eastern Cooperative Oncology Group status of 0 to 1, 36.2% high-risk, and 8.9% autologous transplant candidates. All patients received ≥1 cycle ibrutinib (median, 8 cycles), 39.0% with rituximab. Grade ≥3 toxicity occurred in 20.3%, and 33.8% required dose reductions/delays. At 15.6-month median follow-up, 41.6% discontinued ibrutinib, 8.1% due to toxicity. Of 104 response-assessed patients, overall (ORR) and complete response (CR) rates were 71.2% and 20.2%, respectively. ORR was 77.3% (low risk) vs 59.0% (high risk) (P = .05) and 78.7% (ibrutinib-rituximab) vs 64.9% (ibrutinib; P = .13). Median progression-free survival (PFS) was 26.0 months (all patients); 13.7 months (high risk) vs not reached (NR) (low risk; hazard ratio [HR], 2.19; P = .004). Median overall survival was NR (all); 14.8 months (high risk) vs NR (low risk; HR, 2.36; P = .005). Median post-ibrutinib survival was 1.4 months, longer in 41.9% patients receiving subsequent treatment (median, 8.6 vs 0.6 months; HR, 0.36; P = .002). Ibrutinib with or without rituximab was effective and well tolerated as first-line treatment of MCL, including older and transplant-ineligible patients. PFS and OS were significantly inferior in one-third of patients with high-risk disease and those unsuitable for post-ibrutinib treatment, highlighting the need for novel approaches in these groups.


Assuntos
Adenina , Linfoma de Célula do Manto , Piperidinas , Adulto , Idoso , Feminino , Humanos , Masculino , Adenina/análogos & derivados , Estudos de Coortes , Inglaterra , Linfoma de Célula do Manto/tratamento farmacológico , Rituximab/uso terapêutico
14.
J Cell Physiol ; 228(2): 322-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22688668

RESUMO

Human pulmonary arterial smooth muscle cells (PASMC) were isolated from elastic pulmonary arteries dissected from lungs of individuals with and without pulmonary arterial hypertension (PAH). Reflecting increased smooth muscle constriction in cells from PAH subject, Ca(2+) influx in response to endothelin-1 (ET-1) increased in all the PAH PASMC populations relative to the normal donor control cells. The ETA receptor mRNA levels remained unchanged, whereas the ETB receptor mRNA levels decreased in both heritable and idiopathic PAH-derived PASMC. All the PASMC populations expressed considerably higher ETA compared to ETB receptor number. Both ETA and ETB receptor numbers were reduced in bone morphogenetic protein receptor type II (BMPR2) mutation PAH. ETB receptors showed a particular reduction in number. Phospho-antibody array analysis of normal and BMPR2 deletion PASMC illustrated ERK and Akt activation to be the most prominent and to be taking place principally through ETB receptors in normal PASMC, but primarily through ETA receptors in PASMC from BMPR2 PAH subjects. Additionally in the PAH cells the total relative ET-1 signal response was markedly reduced. Western analysis from the BMPR2 PASMC duplicated the array results, whereas PASMC from iPAH subjects showed variability with most samples continuing to signal through ETB. In sum, these results indicate that generally both receptors are reduced in PAH particularly ETB, and that ETB signaling through protein kinases becomes markedly reduced in BMPR2 PASMC, while it continues in IPAH. Importantly, the data suggest that caution must be taken when applying ET-1 receptor antagonist therapy to PAH patients.


Assuntos
Hipertensão Pulmonar/fisiopatologia , Receptor de Endotelina A/fisiologia , Receptor de Endotelina B/fisiologia , Transdução de Sinais/fisiologia , Adulto , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/fisiologia , Cálcio/metabolismo , Células Cultivadas , Hipertensão Pulmonar Primária Familiar , Feminino , Humanos , Hipertensão Pulmonar/genética , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/fisiologia , Mutação , Artéria Pulmonar/fisiopatologia , Receptor de Endotelina A/biossíntese , Receptor de Endotelina B/biossíntese
15.
J Pept Sci ; 19(4): 257-62, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23436727

RESUMO

The dimerization of the G protein-coupled receptors for endothelin-1 (ET-1), endothelin A receptor (ETA) and endolethin B receptor (ETB), is well established. However, the signaling consequences of the homodimerization and heterodimerization of ETA and ETB is not well understood. Here, we demonstrate that peptides derived from the C-termini of these receptors regulate the signaling capacity of ET-1. The C-termini of the ETA and ETB receptors are believed to consist of three α-helices, which may serve as points of interaction between the receptors. The third α-helix in the C-terminus is of particular interest because of its amphipathic nature. In a cell line expressing only the ETA receptor, expression of residues Y430-S442, representing the third helix of the ETB C-terminus, leads to a dramatic increase in the signaling induced by ET-1. In contrast, in a cell line containing only ETB , Y430-S442 has an antagonistic effect, slightly reducing the ET-1 induced signal. Computational docking results suggest that the α-helical ETB -derived peptide binds to the second and third intracellular loops of the ETA receptor consistent with the alteration of its signaling capacity. Our results described here provide important insight into ETA /ETB receptor interactions and possibly a new approach to regulate specific G protein-coupled receptor signal transmission.


Assuntos
Endotelina-1 , Receptor de Endotelina A , Receptor de Endotelina B , Transdução de Sinais/fisiologia , Animais , Células CHO , Cricetinae , Cricetulus , Endotelina-1/química , Endotelina-1/genética , Endotelina-1/metabolismo , Humanos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Ratos , Receptor de Endotelina A/química , Receptor de Endotelina A/genética , Receptor de Endotelina A/metabolismo , Receptor de Endotelina B/química , Receptor de Endotelina B/genética , Receptor de Endotelina B/metabolismo
16.
Exp Cell Res ; 318(10): 1125-33, 2012 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-22504006

RESUMO

Endothelin-1 (ET-1) is a vasoactive peptide which signals through two G-protein coupled receptors, endothelin receptor A (ETA) and B (ETB). We determined that ET-1 activation of its ETB receptor in stably cDNA transfected CHO cells leads to a 55% reduction in cell number by end-point cell counting and a 35% decrease in cell growth by a real-time cell-substrate impedance-based assay after 24h of cell growth. When CHO ETB cells were synchronized in the late G1 cell cycle phase, ET-1 delayed their S phase progression compared to control by 30% as determined by [(3)H]-thymidine incorporation. On the other hand, no such delay was observed during late G2/M to G1 transit when cells were treated with ET-1 after release from mitotic arrest. Using the cell-substrate impedance-based assay, we observed that ET-1 induces opposing morphological changes in CHO ETA and CHO ETB cells with ETB causing an increase in the cell footprint and ETA a decrease. Likewise, in pulmonary artery smooth muscle cells, which express both ETA and ETB receptors, ET-1 induces an ETA-dependent contraction and an ETB dependent dilation. These results are shedding light on a possible beneficial role for ETB in diseases involving ET-1 dysfunction such as pulmonary hypertension.


Assuntos
Proliferação de Células , Endotelina-1/fisiologia , Receptor de Endotelina B/metabolismo , Animais , Células CHO , Contagem de Células , Ciclo Celular , Forma Celular/efeitos dos fármacos , Cricetinae , DNA/biossíntese , Impedância Elétrica , Antagonistas do Receptor de Endotelina B , Humanos , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/fisiologia , Oligopeptídeos/farmacologia , Piperidinas/farmacologia , Artéria Pulmonar/citologia , Receptor de Endotelina A/metabolismo , Receptor de Endotelina B/agonistas , Transdução de Sinais
18.
J Neurosurg Spine ; 38(5): 595-606, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36640098

RESUMO

OBJECTIVE: Methylprednisolone (MP) to treat acute traumatic spinal cord injury (ATSCI) remains controversial since the release of the second National Acute Spinal Cord Injury Study (NASCIS2) in 1990. As two historical studies, NASCIS2 and Sygen in ATSCI, used identical MP dosages, it was possible to construct a new case-level pooled ATSCI data set satisfying contemporary criteria and able to clarify the effect of MP. METHODS: The new pooled data set was first modernized by excluding patients with injury levels caudal to T10, lower-extremity American Spinal Injury Association (ASIA) motor scores (LEMSs) ≥ 46, Glasgow Coma Scale scores ≤ 11, and age < 15 or > 75 years, and then standardized to the ASIA grading and scoring format. A new updated NASCIS2 data set from this pooled data set contained 31.6% fewer patients than the 1990 NASCIS2 data set. RESULTS: In the new pooled data set, recovery of LEMSs from baseline to 26 weeks, the primary outcome variable, was separated statistically into five different injury severity cohorts (p < 0.0001). The severity cohorts contained groups with severe floor (62.9%) and ceiling (10.7%) effects, which do not contribute to drug effects. The new NASCIS2 data set duplicated the p value for MP versus placebo in the sub-subgroup analysis of MP initiated ≤ 8 hours (the subgroup) and recovery of motor function on only the right side of the body (a further subgroup within the ≤ 8-hour subgroup), presented as the positive MP effect in the original NASCIS2 reporting. However, current statistical interpretation considers results seen only in post hoc sub-subgroups, without multi-test corrections, to be random effects without clinical significance. The combined case-level pooled data set from the NASCIS2 and Sygen studies increased the MP group from 106 to 431 patients, creating a new MP combined group. This new data set served as a surrogate for a contemporary MP study and found that administration of MP did not enhance ASIA motor score improvement in the lower extremities at 26 weeks. Secondary analysis of descending ASIA motor and sensory cervical neurological levels in cervical ATSCI patients at 26 weeks also found no MP drug effect. CONCLUSIONS: Analysis of both the new updated NASCIS2 data set and the new case-matched pooled data set from two historical ATSCI studies revealed that administration of MP after spinal cord injury did not demonstrate any enhancement in neurological recovery at 26 weeks. The results of this analysis warrant review by clinical guideline groups.


Assuntos
Traumatismos da Medula Espinal , Traumatismos da Coluna Vertebral , Humanos , Estados Unidos , Idoso , Metilprednisolona , Recuperação de Função Fisiológica
19.
Nat Commun ; 14(1): 2376, 2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37105972

RESUMO

Paleontological reconstructions of plankton community structure during warm periods of the Cenozoic (last 66 million years) reveal that deep-dwelling 'twilight zone' (200-1000 m) plankton were less abundant and diverse, and lived much closer to the surface, than in colder, more recent climates. We suggest that this is a consequence of temperature's role in controlling the rate that sinking organic matter is broken down and metabolized by bacteria, a process that occurs faster at warmer temperatures. In a warmer ocean, a smaller fraction of organic matter reaches the ocean interior, affecting food supply and dissolved oxygen availability at depth. Using an Earth system model that has been evaluated against paleo observations, we illustrate how anthropogenic warming may impact future carbon cycling and twilight zone ecology. Our findings suggest that significant changes are already underway, and without strong emissions mitigation, widespread ecological disruption in the twilight zone is likely by 2100, with effects spanning millennia thereafter.


Assuntos
Plâncton , Água do Mar , Água do Mar/química , Ciclo do Carbono , Temperatura , Oceanos e Mares
20.
J Neurosurg Spine ; 39(6): 815-821, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37728372

RESUMO

OBJECTIVE: The goal of this study was to determine the effect of the degree of frailty on long-term neurological and functional outcomes after surgery for degenerative cervical myelopathy (DCM). METHODS: A combined database of patients enrolled in the Cervical Spondylotic Myelopathy-North America and Cervical Spondylotic Myelopathy-International prospective international multicenter observational studies who underwent surgery for DCM was used as the source data. All patients underwent baseline and follow-up assessment at 2 years after surgery for functional, disability, and quality of life measurements (modified Japanese Orthopaedic Association [mJOA] scale, Neck Disability Index, SF-36 physical and mental component summary scores). Patients were separated into 4 groups according to their baseline modified frailty index 5-point scale score: not frail, pre-frail, frail, and severely frail. Differences among groups were analyzed at baseline and at 2 years after surgery, including change in scores (delta values) and the odds ratio of achieving the minimum clinically important difference (MCID) through univariate and multivariable logistic regression adjusting for age, approach, number of levels treated, and sex. RESULTS: A total of 757 patients (63% male) with a mean age of 56 (95% CI 55.5-57.2) years were included: 470 patients underwent an anterior approach, 310 had a posterior approach, and 23 had a combined anterior/posterior approach. A total of 50% (n = 378) of patients were classified as not frail, with 33% (n = 250) pre-frail, 13% (n = 101) frail, and 4% (n = 28) severely frail. The baseline mJOA score was significantly lower with increasing frailty (14.00 [95% CI 13.75-14.19] for not frail vs 9.71 [95% CI 9.01-10.42] for severely frail patients; p < 0.05), but the change at 2 years was not significantly different among all groups (2.43 [95% CI 2.16-2.71] for not frail vs 2.56 [95% CI 1.10-4.02] for severely frail). The SF-36 delta values were also not different among groups, but significantly worse at baseline with increasing frailty. The odds ratio of achieving MCID for mJOA was significantly higher in the not frail group (1.89 [95% CI 1.36-2.61]; p < 0.05) compared to the other frailty cohorts, which remained after adjusting for age, approach, levels treated, and sex. The odds ratio of achieving MCID for the SF-36 domains was similar among all frailty groups. CONCLUSIONS: Increasing frailty is associated with worse baseline functional and quality of life measures in patients undergoing surgery for DCM. Frailty does not affect the magnitude of improvement in outcome measures after surgery, but reduces the chance of achieving the MCID for functional impairment significantly. Preoperative frailty assessment can therefore help guide clinicians in managing expectations after surgery for DCM. Potentially modifiable factors should be optimized in frail patients preoperatively to enhance functional outcomes.


Assuntos
Fragilidade , Doenças da Medula Espinal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vértebras Cervicais/cirurgia , Fragilidade/complicações , Fragilidade/cirurgia , Pescoço , Estudos Prospectivos , Qualidade de Vida , Doenças da Medula Espinal/cirurgia , Resultado do Tratamento
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