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1.
Nat Commun ; 15(1): 7042, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39147773

RESUMEN

Extreme global warming can produce hydroclimate changes that remain poorly understood for sub-tropical latitudes. Late Palaeocene-early Eocene (LPEE; ~58-52 Ma) proto-Mediterranean zones of the western Tethys offer opportunities to assess hydroclimate responses to massive carbon cycle perturbations. Here, we reconstruct LPEE hydroclimate conditions of these regions and find that carbon cycle perturbations exerted controls on orbitally forced hydroclimate variability. Long-term (~6 Myr) carbon cycle changes induced a gradual precipitation/moisture reduction, which was exacerbated by some short-lived (<200 kyr) carbon cycle perturbations that caused rapid warming and exceptionally dry conditions in western Tethyan continental areas. Hydroclimate recovery following the greatest short-lived global warming events took ~24-27 kyr. These observations support the notion that anthropogenically driven warming can cause widespread aridification with impacts that may last tens of thousands of years.

2.
J Patient Rep Outcomes ; 8(1): 102, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39196484

RESUMEN

BACKGROUND: Coronary artery disease (CAD) confers increased risks of premature mortality, non-fatal morbidity, and significant impairment in functional status and health-related quality of life. Routine administration of electronic patient-reported outcome measures (PROMs) and its real time delivery to care providers is known to have the potential to inform routine cardiac care and to improve quality of care and patient outcomes. This study describes a user-centered development and evaluation of the Alberta Provincial Project for Outcomes Assessment (APPROACH) electronic Patient Reported Outcomes Measurement (e-PROM) system. This e-PROM system is an electronic system for the administration of PROMs to patients with CAD and the delivery of the summarized information to their care providers to facilitate patient-physician communication and shared decision-making. This electronic platform was designed to be accessible via web-based and hand-held devices. Heuristic and user acceptance evaluation were conducted with patients and attending care providers. RESULTS: The APPROACH e-PROM system was co-developed with patients and care providers, research investigators, informaticians and information technology experts. Five PROMs were selected for inclusion in the online platform after consultations with patient partners, care providers, and PROMs experts: the Seattle Angina Questionnaire, Patient Health Questionnaire, EuroQOL, and Medical Outcomes Study Social Support Survey, and Self-Care of Coronary Heart Disease Inventory. The heuristic evaluation was completed by four design experts who examined the usability of the prototype interfaces. User acceptance testing was completed with 13 patients and 10 cardiologists who evaluated prototype user interfaces of the e-PROM system. CONCLUSION: Both patients and physicians found the APPROACH e-PROM system to be easy to use, understandable, and acceptable. The APPROACH e-PROM system provides a user-informed electronic platform designed to incorporate PROMs into the delivery of individualized cardiac care for persons with CAD.


Asunto(s)
Enfermedad de la Arteria Coronaria , Medición de Resultados Informados por el Paciente , Humanos , Enfermedad de la Arteria Coronaria/terapia , Femenino , Masculino , Alberta , Calidad de Vida , Persona de Mediana Edad , Diseño Centrado en el Usuario , Anciano , Internet , Relaciones Médico-Paciente
3.
Br J Haematol ; 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-39031781

RESUMEN

Despite significant progress in treating chronic lymphocytic leukaemia (CLL), resistance to therapy remains challenging. NOTCH1 activation, common in CLL, confers adverse prognosis. This study explores the impact of NOTCH1 signalling on venetoclax sensitivity in vitro. Although NOTCH1 activation minimally impaired the susceptibility of CLL cells to venetoclax, ex vivo cell competition studies reveal that cells with constitutive NOTCH1 activation outgrew their wild-type counterparts in the presence of ongoing venetoclax exposure. Our findings suggest that while NOTCH1 activation is insufficient to confer venetoclax refractoriness, there is enhanced potential for cells with NOTCH1 activation to escape and thus become fully resistant to venetoclax.

4.
J Nucl Med ; 65(9): 1467-1472, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39054283

RESUMEN

Alzheimer disease is a neurodegenerative disorder with limited treatment options. It is characterized by the presence of several biomarkers, including amyloid-ß aggregates, which lead to oxidative stress and neuronal decay. Targeted α-therapy (TAT) has been shown to be efficacious against metastatic cancer. TAT takes advantage of tumor-localized α-particle emission to break disease-associated covalent bonds while minimizing radiation dose to healthy tissues due to the short, micrometer-level, distances traveled. We hypothesized that TAT could be used to break covalent bonds within amyloid-ß aggregates and facilitate natural plaque clearance mechanisms. Methods: We synthesized a 213Bi-chelate-linked benzofuran pyridyl derivative (BiBPy) and generated [213Bi]BiBPy, with a specific activity of 120.6 GBq/µg, dissociation constant of 11 ± 1.5 nM, and logP of 0.14 ± 0.03. Results: As the first step toward the validation of [213Bi]BiBPy as a TAT agent for the reduction of Alzheimer disease-associated amyloid-ß, we showed that brain homogenates from APP/PS1 double-transgenic male mice (6-9 mo old) incubated with [213Bi]BiBPy exhibited a marked reduction in amyloid-ß plaque concentration as measured using both enzyme-linked immunosorbent and Western blotting assays, with a half-maximal effective concentration of 3.72 kBq/pg. Conclusion: This [213Bi]BiBPy-concentration-dependent activity shows that TAT can reduce amyloid plaque concentration in vitro and supports the development of targeting systems for in vivo validations.


Asunto(s)
Péptidos beta-Amiloides , Benzofuranos , Benzofuranos/química , Benzofuranos/farmacología , Benzofuranos/uso terapéutico , Animales , Ratones , Péptidos beta-Amiloides/metabolismo , Radioisótopos/química , Agregado de Proteínas/efectos de los fármacos , Partículas alfa/uso terapéutico , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , Marcaje Isotópico , Piridinas/química , Piridinas/uso terapéutico , Masculino , Humanos
5.
Sci Adv ; 10(25): eadm8270, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38896619

RESUMEN

East Asian winter monsoon (EAWM) activity has had profound effects on environmental change throughout East Asia and the western Pacific. Much attention has been paid to Quaternary EAWM evolution, while long-term EAWM fluctuation characteristics and drivers remain unclear, particularly during the late Miocene when marked global climate and Asian paleogeographic changes occurred. To clarify understanding of late Miocene EAWM evolution, we developed a high-precision 9-million-year-long stacked EAWM record from Northwest Pacific Ocean abyssal sediments based on environmental magnetism, sedimentology, and geochemistry, which reveals a strengthened late Miocene EAWM. Our paleoclimate simulations also indicate that atmospheric CO2 decline played a vital role in this EAWM intensification over the Northwest Pacific Ocean compared to other factors, including central Asian orogenic belt and northeastern Tibetan Plateau uplift and Antarctic ice-sheet expansion. Our results expand understanding of EAWM evolution from inland areas to the open ocean and indicate the importance of atmospheric CO2 fluctuations on past EAWM variability over large spatial scales.

6.
Methods Enzymol ; 698: 89-109, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38886041

RESUMEN

Tyr-derived cyclic peptide natural products are formed by enzymatic manifolds that oxidatively cross-link embedded phenolic side chains of tyrosine (Tyr) and 4-hydroxyphenylglycine residues during their controlled production. Bioactive Tyr-derived cyclic peptides, such as the arylomycins and vancomycins, continue to motivate the development of enzymatic and chemical strategies for their de novo assembly and modification. However, chemical access to these structurally diverse natural cycles can be challenging and step intensive. Therefore, we developed an oxidative procedure to selectively convert Tyr-containing N4-substituted 1,2,4-triazolidine-3,5-dione peptides (urazole peptides) into stable Tyr-linked cyclic peptides. We show that Tyr-containing urazole peptides are simple to prepare and convert into reactive N4-substituted 1,2,4-triazoline-3,5-dione peptides by oxidation, which then undergo spontaneous cyclization under mildly basic aqueous conditions to form a cross-linkage with the phenol side chain of embedded Tyr residues. Using this approach, we have demonstrated access to over 25 Tyr-linked cyclic peptides (3- to 11-residue cycles) with good tolerance of native residue side chain functionalities. Importantly, this method is simple to perform, and product formation can be quickly confirmed by mass spectrometric and 1H NMR spectroscopic analyses.


Asunto(s)
Péptidos Cíclicos , Tirosina , Tirosina/química , Ciclización , Péptidos Cíclicos/química , Péptidos Cíclicos/síntesis química , Triazoles/química , Oxidación-Reducción
7.
Cancer Cell ; 42(5): 850-868.e9, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38670091

RESUMEN

TP53-mutant blood cancers remain a clinical challenge. BH3-mimetic drugs inhibit BCL-2 pro-survival proteins, inducing cancer cell apoptosis. Despite acting downstream of p53, functional p53 is required for maximal cancer cell killing by BH3-mimetics through an unknown mechanism. Here, we report p53 is activated following BH3-mimetic induced mitochondrial outer membrane permeabilization, leading to BH3-only protein induction and thereby potentiating the pro-apoptotic signal. TP53-deficient lymphomas lack this feedforward loop, providing opportunities for survival and disease relapse after BH3-mimetic treatment. The therapeutic barrier imposed by defects in TP53 can be overcome by direct activation of the cGAS/STING pathway, which promotes apoptosis of blood cancer cells through p53-independent BH3-only protein upregulation. Combining clinically relevant STING agonists with BH3-mimetic drugs efficiently kills TRP53/TP53-mutant mouse B lymphoma, human NK/T lymphoma, and acute myeloid leukemia cells. This represents a promising therapy regime that can be fast-tracked to tackle TP53-mutant blood cancers in the clinic.


Asunto(s)
Apoptosis , Proteínas de la Membrana , Proteína p53 Supresora de Tumor , Proteína p53 Supresora de Tumor/genética , Humanos , Animales , Ratones , Proteínas de la Membrana/genética , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Mutación , Neoplasias Hematológicas/tratamiento farmacológico , Neoplasias Hematológicas/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Fragmentos de Péptidos/farmacología , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Transducción de Señal/efectos de los fármacos , Proteínas Proto-Oncogénicas/genética
8.
Nat Commun ; 15(1): 3364, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38641605

RESUMEN

Intensification of northern hemisphere glaciation (iNHG), ~2.7 million years ago (Ma), led to establishment of the Pleistocene to present-day bipolar icehouse state. Here we document evolution of orbital- and millennial-scale Asian winter monsoon (AWM) variability across the iNHG using a palaeomagnetically dated centennial-resolution grain size record between 3.6 and 1.9 Ma from a previously undescribed loess-palaeosol/red clay section on the central Chinese Loess Plateau. We find that the late Pliocene-early Pleistocene AWM was characterized by combined 41-kyr and ~100-kyr cycles, in response to ice volume and atmospheric CO2 forcing. Northern hemisphere ice sheet expansion, which was accompanied by an atmospheric CO2 concentration decline, substantially increased glacial AWM intensity  and its orbitally oscillating amplitudes across the iNHG. Superposed on orbital variability, we find that millennial AWM intensity fluctuations persisted during both the warmer (higher-CO2) late Pliocene and colder (lower-CO2) early Pleistocene, in response to both external astronomical forcing and internal climate dynamics.

9.
Blood ; 144(8): 867-872, 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-38662991

RESUMEN

ABSTRACT: In the phase 2 clinical trial (AIM) of venetoclax-ibrutinib, 24 patients with mantle cell lymphoma (MCL; 23 with relapsed/refractory [R/R] disease) received ibrutinib 560 mg and venetoclax 400 mg both once daily. High complete remission (CR) and measurable residual disease negative (MRD-negative) CR rates were previously reported. With median survivor follow-up now exceeding 7 years, we report long-term results. Treatment was initially continuous, with elective treatment interruption (ETI) allowed after protocol amendment for patients in MRD-negative CR. For R/R MCL, the estimated 7-year progression-free survival (PFS) was 30% (95% confidence interval [CI], 14-49; median, 28 months; 95% CI, 13-82) and overall survival (OS) was 43% (95% CI, 23-62; median, 32 months; 95% CI, 15 to not evaluable). Eight patients in MRD-negative CR entered ETI for a median of 58 months (95% CI, 37-79), with 4 experiencing disease recurrence. Two of 3 reattained CR on retreatment. Time-to-treatment failure (TTF), which excluded progression in ETI for those reattaining response, was 39% overall and 68% at 7 years for responders. Beyond 56 weeks, grade ≥3 and serious adverse events were uncommon. Newly emergent or increasing cardiovascular toxicity were not observed beyond 56 weeks. We demonstrate long-term durable responses and acceptable toxicity profile of venetoclax-ibrutinib in R/R MCL and show feasibility of treatment interruption while maintaining ongoing disease control. This trial was registered at www.clinicaltrials.gov as #NCT02471391.


Asunto(s)
Adenina , Protocolos de Quimioterapia Combinada Antineoplásica , Compuestos Bicíclicos Heterocíclicos con Puentes , Linfoma de Células del Manto , Piperidinas , Sulfonamidas , Humanos , Linfoma de Células del Manto/tratamiento farmacológico , Linfoma de Células del Manto/mortalidad , Sulfonamidas/administración & dosificación , Sulfonamidas/uso terapéutico , Sulfonamidas/efectos adversos , Compuestos Bicíclicos Heterocíclicos con Puentes/administración & dosificación , Compuestos Bicíclicos Heterocíclicos con Puentes/efectos adversos , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Masculino , Femenino , Anciano , Persona de Mediana Edad , Adenina/análogos & derivados , Adenina/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Piperidinas/administración & dosificación , Piperidinas/efectos adversos , Piperidinas/uso terapéutico , Anciano de 80 o más Años , Inducción de Remisión , Resultado del Tratamiento , Adulto , Estudios de Seguimiento , Supervivencia sin Enfermedad
10.
Clin Appl Thromb Hemost ; 30: 10760296241241525, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38523315

RESUMEN

European real-world data indicate that front-line treatment with caplacizumab is associated with improved clinical outcomes compared with delayed caplacizumab treatment. The objective of the study was to describe the characteristics, treatment patterns, and outcomes in hospitalized patients with an immune-mediated thrombotic thrombocytopenic purpura (iTTP) episode treated with front-line versus delayed caplacizumab in the US. This retrospective cohort analysis of a US hospital database included adult patients (≥18 years) with an acute iTTP episode (a diagnosis of thrombotic microangiopathy and ≥1 therapeutic plasma exchange [TPE] procedure) from January 21, 2019, to February 28, 2021. Unadjusted baseline characteristics, treatment patterns, healthcare resource utilization, and costs were compared between patients who received front-line versus delayed (<2 vs ≥2 days after TPE initiation) caplacizumab treatment. Out of 39 patients, 16 (41.0%) received front-line and 23 (59.0%) received delayed treatment with caplacizumab. Baseline characteristics and symptoms were similar between the two groups. Patients who received front-line caplacizumab treatment had significantly fewer TPE administrations (median: 5.0 vs 12.0); and a significantly shorter hospital stay (median: 9.0 days vs 16.0 days) than patients receiving delayed caplacizumab therapy. Both of these were significantly lower in comparison of means (t-test P < .01). Median inpatient costs (inclusive of caplacizumab costs) were 54% higher in the delayed treated patients than in the front-line treated patients (median: $112 711 vs $73 318). TPE-specific cost was lower in the front-line treated cohort (median: $6 989 vs $10 917). In conclusion, front-line treatment with caplacizumab had shorter hospitalizations, lower healthcare resource utilization, and lower costs than delayed caplacizumab treatment after TPE therapy.


Asunto(s)
Púrpura Trombocitopénica Idiopática , Púrpura Trombocitopénica Trombótica , Anticuerpos de Dominio Único , Trombosis , Adulto , Humanos , Púrpura Trombocitopénica Trombótica/tratamiento farmacológico , Estudios Retrospectivos , Anticuerpos de Dominio Único/efectos adversos , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico , Intercambio Plasmático , Trombosis/tratamiento farmacológico , Proteína ADAMTS13 , Hospitales
11.
Blood Cancer J ; 14(1): 54, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38531863

RESUMEN

Despite an increasing desire to use historical cohorts as "synthetic" controls for new drug evaluation, limited data exist regarding the comparability of real-world outcomes to those in clinical trials. Governmental cancer data often lacks details on treatment, response, and molecular characterization of disease sub-groups. The Australasian Leukaemia and Lymphoma Group National Blood Cancer Registry (ALLG NBCR) includes source information on morphology, cytogenetics, flow cytometry, and molecular features linked to treatment received (including transplantation), response to treatment, relapse, and survival outcome. Using data from 942 AML patients enrolled between 2012-2018, we assessed age and disease-matched control and interventional populations from published randomized trials that led to the registration of midostaurin, gemtuzumab ozogamicin, CPX-351, oral azacitidine, and venetoclax. Our analyses highlight important differences in real-world outcomes compared to clinical trial populations, including variations in anthracycline type, cytarabine intensity and scheduling during consolidation, and the frequency of allogeneic hematopoietic cell transplantation in first remission. Although real-world outcomes were comparable to some published studies, notable differences were apparent in others. If historical datasets were used to assess the impact of novel therapies, this work underscores the need to assess diverse datasets to enable geographic differences in treatment outcomes to be accounted for.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Humanos , Recurrencia Local de Neoplasia/tratamiento farmacológico , Resultado del Tratamiento , Citarabina/uso terapéutico , Gemtuzumab/uso terapéutico , Leucemia Mieloide Aguda/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico
12.
Front Neurol ; 15: 1321032, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38426172

RESUMEN

Introduction: Sleep is critical to the health, wellbeing and performance of military personnel during basic training. This two-part study evaluated sleep-wake patterns and sleep disturbances in junior soldiers (JS) and infantry recruits in Autumn 2021 (study 1), and non-infantry recruits in spring 2022 (study 2). Methods: During studies 1 and 2, validated wearable technology combined with a sleep diary was used to quantify sleep-wake indices, sleep disturbances and perceptions of sleep quality. Sleep diary data was analysed descriptively. A series of repeated-measures ANOVAs examined differences in objective sleep-wake indices. Correlation analysis determined associations between time in bed (TIB) and total sleep time (TST). Results: Significant (p < 0.05) differences in most sleep-wake indices were observed between weeks of basic training for all cohorts. Strong positive correlations between TIB and TST were observed for each cohort across basic training (r = 0.681 - 0.970, p < 0.001), with longer TST associated with greater TIB. The mean±SD sleep duration (hours and mins [hm]) for JS (06:22 ± 00:27hm), non-infantry (05:41 ± 00:47hm) and infantry (05:46 ± 00:34hm) recruits across basic training was consistently below national recommendations. The mean±SD bed and wake times for JS (bedtime: 23:01 ± 00:32hm; awake: 05:34 ± 00:10hm), non-infantry (bedtime: 23:38 ± 01:09hm; awake: 04:47 ± 00:58hm), and infantry (bedtime: 23:13 ± 00:29hm; awake: 05:38 ± 00:26hm) recruits varied across weeks of basic training, with over 80% reporting "fairly bad" or "very bad" sleep quality and frequent periods of "dozing off" during daytime activity. The most commonly reported sleep disturbing factors identified during basic training involved: late-night military admin (e.g., ironing, boot cleaning, kit set up etc), early morning wake times, extraneous noise, light and hot room temperatures within the primary sleeping environment, bed/mattress discomfort, muscle soreness and feelings of stress and anxiety. Discussion/Conclusion: Our findings contribute to the existing evidence that long-term sleep loss is pervasive during initial military training programmes. The average sleep durations indicate chronic and unrecoverable sleep loss which would be expected to significantly impair physical and cognitive military performance, and increase the risk of injury, illness and attrition rates during basic training. Changes in the design and scheduling of basic training programmes to enable, at the least, minimum sleep recommendations to be met, and to improve sleep hygiene in the primary sleeping environment are warranted.

13.
Front Bioeng Biotechnol ; 12: 1359388, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38449673

RESUMEN

The concept of Data Transportability (DT) of Confined Field Testing (CFT) to support the Environmental Risk Assessment (ERA) of Genetically Modified (GM) plants was first introduced in the literature by Garcia-Alonso et al., in 2014. Since then, DT has been discussed in many countries and regions as a concept to prevent duplication of regulatory studies without compromising quality of the ERA. However, despite its usefulness and scientific justification, DT is not well adopted at this time and many regulatory agencies around the world require additional in-country CFT be conducted before approving GM plants. Based on the current circumstances, the authors organized a parallel session entitled "Introduction and Scientific Justification of DT for CFT for the ERA of GM plants" at 16th ISBR (the International Society for Biosafety Research). This session mainly consisted of the following three parts. The first two speakers, Andrew Roberts and Abigail Simmons provided an overview of DT and examples of conditions for the transportability of field data/conclusions advocated in the peer-reviewed scientific journals. Next, the current status of DT adoption in some countries/regions such as Japan and Africa, and a theoretical case study for Argentina were introduced by Kazuyuki Hiratsuka, Douglas Miano, and Facundo Vesprini, respectively. Lastly, a risk hypothesis-based approach for DT which was developed in advance by the five speakers of this parallel session, was introduced. During the discussion, there was a common understanding that transition to the risk hypothesis-based approach for DT was scientifically appropriate, considering the accumulated evidences that several countries have conducted confirmatory local CFT for more than 20 years but they have not detected any differences related to the ERA assessment endpoints in GM crops. The risk hypothesis-based approach for DT introduced here is expected to play an important role in discussions on the implementation of DT in various parts of the world in the future.

15.
Behav Sci (Basel) ; 14(2)2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38392499

RESUMEN

To describe something in terms of its purpose or function is to describe its teleology. Previous studies have found that teleological beliefs are positively related to anthropomorphism, and that anthropomorphism decreases the perceived unpredictability of non-human agents. In the current study, we explore these relationships using the highly salient example of beliefs about the coronavirus pandemic. Results showed that both anthropomorphism and teleology were negatively associated with perceived uncertainty and threat, and positively associated with self-reported behavioural change in response to the pandemic. These findings suggest that highly anthropomorphic and teleological individuals may view coronavirus as agentive and goal-directed. While anthropomorphic and teleological beliefs may facilitate behavioural change in response to the pandemic, we also found that the associated reduction in uncertainty and threat may be detrimental to behavioural change. We discuss the implications of these findings for messaging about global events more broadly.

16.
J Am Chem Soc ; 146(7): 4444-4454, 2024 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-38166378

RESUMEN

Lasso peptides make up a class of natural products characterized by a threaded structure. Given their small size and stability, chemical synthesis would offer tremendous potential for the development of novel therapeutics. However, the accessibility of the pre-folded lasso architecture has limited this advance. To better understand the folding process de novo, simulations are used herein to characterize the folding propensity of microcin J25 (MccJ25), a lasso peptide known for its antimicrobial properties. New algorithms are developed to unambiguously distinguish threaded from nonthreaded precursors and determine handedness, a key feature in natural lasso peptides. We find that MccJ25 indeed forms right-handed pre-lassos, in contrast to past predictions but consistent with all natural lasso peptides. Additionally, the native pre-lasso structure is shown to be metastable prior to ring formation but to readily transition to entropically favored unfolded and nonthreaded structures, suggesting that de novo lasso folding is rare. However, by altering the ring forming residues and appending thiol and thioester functionalities, we are able to increase the stability of pre-lasso conformations. Furthermore, conditions leading to protonation of a histidine imidazole side chain further stabilize the modified pre-lasso ensemble. This work highlights the use of computational methods to characterize lasso folding and demonstrates that de novo access to lasso structures can be facilitated by optimizing sequence, unnatural modifications, and reaction conditions like pH.


Asunto(s)
Bacteriocinas , Péptidos , Conformación Proteica , Péptidos/química , Bacteriocinas/química , Antibacterianos/química
18.
Blood Adv ; 8(8): 1992-2004, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38290108

RESUMEN

ABSTRACT: Chromosome 17p deletion (del[17p]) is associated with poor prognosis in patients with chronic lymphocytic leukemia (CLL). Venetoclax is approved for treatment of previously untreated and relapsed/refractory (R/R) CLL, including patients with del(17p), based on the open-label, multicenter, phase 2 M13-982 trial (NCT01889186). Here, we detail the 6-year follow-up analysis for M13-982. A total of 158 patients with previously untreated (n = 5) or R/R (n = 153) del(17p) CLL received 400 mg venetoclax daily after initial ramp-up until progressive disease. After a median follow-up of 70 months, the best objective response rate (ORR) was 77% (21% complete remission [CR] and 49% partial remission [PR]), with a median duration of response (DOR) of 39.3 months (95% confidence interval [CI], 31.1-50.5). The median progression-free survival (PFS) was 28.2 months (95% CI, 23.4-37.6), and median overall survival (OS) was 62.5 months (95% CI, 51.7-not reached), with 16% of patients remaining on treatment after 6 years. Multivariable analysis did not identify statistically significant correlation between patient subgroups defined by clinical or laboratory variables and ORR or PFS. The most common grade ≥3 adverse events were neutropenia (42%), infections (33%), anemia (16%), and thrombocytopenia (16%). Post hoc comparative analyses of PFS and OS from treatment initiation, from a 24-month landmark, and by minimal residual disease status were performed between patients with del(17p) in the M13-982 and MURANO studies in the interest of understanding these data in another context. These long-term data show the continued benefits of venetoclax in patients with del(17p) CLL. The trial was registered at www.clinicaltrials.gov as #NCT01889186.


Asunto(s)
Leucemia Linfocítica Crónica de Células B , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/genética , Estudios de Seguimiento , Compuestos Bicíclicos Heterocíclicos con Puentes/efectos adversos , Sulfonamidas/efectos adversos , Recurrencia , Deleción Cromosómica
19.
mBio ; 15(1): e0199923, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38085021

RESUMEN

IMPORTANCE: Bacteria known as pink-pigmented facultative methylotrophs colonize many diverse environments on earth, play an important role in the carbon cycle, and in some cases promote plant growth. However, little is known about how these organisms interact with each other and their environment. In this work, we identify one of the chemical signals commonly used by these bacteria and discover that this signal controls swarming motility in the pink-pigmented facultative methylotroph Methylobacterium fujisawaense DSM5686. This work provides new molecular details about interactions between these important bacteria and will help scientists predict these interactions and the group behaviors they regulate from genomic sequencing information.


Asunto(s)
Methylobacterium , Percepción de Quorum , Acil-Butirolactonas , Methylobacterium/genética
20.
ACS Chem Biol ; 19(1): 81-88, 2024 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-38109560

RESUMEN

Lasso peptides are a structurally distinct class of biologically active natural products defined by their short sequences with impressively interlocked tertiary structures. Their characteristic peptide [1]rotaxane motif confers marked proteolytic and thermal resiliency, and reports on their diverse biological functions have been credited to their exceptional sequence variability. Because of these unique properties, taken together with improved technologies for their biosynthetic production, lasso peptides are emerging as a designable scaffold for peptide-based therapeutic discovery and development. Although the defined structure of lasso peptides is recognized for its remarkable properties, the role of the motif in imparting bioactivity is less understood. For example, sungsanpin and ulleungdin are natural lasso peptides that similarly exhibit encouraging cell migration inhibitory activities in A549 lung carcinoma epithelial cells, despite sharing only one-third of the sequence homology. We hypothesized that the shape of the lasso motif is beneficial for the preorganization of the conserved residues, which might be partially retained in variants lacking the threaded structure. Herein, we describe solid-phase peptide synthesis strategies to prepare acyclic, head-to-side chain (branched), and head-to-tail (macrocyclic) cyclic variants based on the sungsanpin (Sun) and ulleungdin (Uln) sequences. Proliferation assays and time-lapse cell motility imaging studies were used to evaluate the cell inhibitory properties of natural Sun compared with the synthetic Sun and Uln isomers. These studies demonstrate that the lasso motif is not a required feature to slow cancer cell migration and more generally show that these nonthreaded isomers can retain similar activity to the natural lasso peptide despite the differences in their overall structures.


Asunto(s)
Neoplasias Pulmonares , Péptidos , Humanos , Péptidos/farmacología , Péptidos/química , Péptido Hidrolasas , Movimiento Celular
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