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1.
Lancet ; 404(10463): 1668-1676, 2024 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-39426385

RESUMEN

BACKGROUND: Cadonilimab is a bispecific antibody targeting PD-1 and CTLA-4, which has shown substantial clinical benefits in advanced cervical cancer. In the COMPASSION-16 trial, we aimed to evaluate the addition of cadonilimab to first-line standard chemotherapy in persistent, recurrent, or metastatic cervical cancer. METHODS: In this randomised, double-blind, multicentre, placebo-controlled phase 3 trial, women aged 18-75 years across 59 clinical sites in China with previously untreated persistent, recurrent, or metastatic cervical cancer were randomly assigned (1:1) to receive cadonilimab (10 mg/kg) or placebo plus platinum-based chemotherapy with or without bevacizumab every 3 weeks for six cycles, followed by maintenance therapy every 3 weeks for up to 2 years. Randomisation was performed centrally through an interactive web-response system. Stratification factors were the use of bevacizumab (yes or no) and previous concurrent chemoradiotherapy (yes or no). The dual primary outcomes were progression-free survival as assessed by blinded independent central review and overall survival in the full analysis set. This study is registered with ClinicalTrials.gov, NCT04982237; the study has completed enrolment and is ongoing for treatment and follow-up. FINDINGS: 445 eligible women were enrolled between Sept 11, 2021, and June 23, 2022. Median progression-free survival was 12·7 months (95% CI 11·6-16·1) in the cadonilimab group and 8·1 months (7·7-9·6) in the placebo group (hazard ratio 0·62 [95% CI 0·49-0·80], p<0·0001); median overall survival was not reached (27·0 months to not estimable) versus 22·8 months (17·6-29·0), respectively (hazard ratio 0·64 [0·48-0·86], p=0·0011). The most common grade 3 or higher adverse events were decreased neutrophil count, decreased white blood cell count, and anaemia. INTERPRETATION: The addition of cadonilimab to first-line standard chemotherapy significantly improved progression-free survival and overall survival with a manageable safety profile in participants with persistent, recurrent, or metastatic cervical cancer. The data support the use of cadonilimab plus chemotherapy as an efficacious first-line therapy in persistent, recurrent, or metastatic cervical cancer. FUNDING: Akeso Biopharma.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Bevacizumab , Recurrencia Local de Neoplasia , Neoplasias del Cuello Uterino , Humanos , Femenino , Neoplasias del Cuello Uterino/tratamiento farmacológico , Persona de Mediana Edad , Bevacizumab/uso terapéutico , Bevacizumab/administración & dosificación , Método Doble Ciego , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Adulto , China , Recurrencia Local de Neoplasia/tratamiento farmacológico , Anciano , Adulto Joven , Adolescente , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/efectos adversos , Anticuerpos Monoclonales Humanizados/administración & dosificación , Supervivencia sin Progresión
2.
Immun Inflamm Dis ; 12(9): e70015, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39315884

RESUMEN

OBJECTIVE: Radiation proctitis (RP) refers to rectal injury caused by radiation treatment of pelvic and retroperitoneal malignancies, which has a major impact on the treatment prognosis and quality of life of patients with cancer. The tetracyclic triterpene saponin monomer ginsenoside Rg3 (GRg3), the primary bioactive ingredient in ginseng extracts, has therapeutic effects against RP in rats. Here, we validated its efficacy and elucidated its mechanism of action. METHODS: A rat RP model was established in 48 Wistar rats. Rats were randomly divided into control (untreated), irradiation, irradiation + dexamethasone, and irradiation + GRg3 (low-, medium-, and high-dose) groups. After 2 weeks' treatment, serum IL-4, IL-10, and TNF-α levels were tested by enzyme-linked immunosorbent assays. In rectal tissue, Ikbkb, Ikka, and Casp8 mRNA expression was detected by a reverse transcription-quantitative polymerase chain reaction. IKK-ß, IκB-α, p-IκB-α, p50, and caspase-8 protein levels were determined by western blot analysis. RESULTS: GRg3 significantly improved the general condition and histopathological damage in rats with RP. Moreover, GRg3 decreased the levels of factors that promote inflammation (TNF-α) and increased the levels of factors that reduce inflammation (IL-4 and IL-10). GRg3 markedly reduced the activation of NF-κB and caspase-8 signaling pathways. CONCLUSIONS: Thus, GRg3 may reduce the inflammatory response by blocking the NF-κB signaling pathway and improving the balance of inflammation-related factors. GRg3 may also inhibit intestinal cell apoptosis by suppressing the TNF-α/caspase-8 signaling cascade, thereby reducing radiological rectal injury. Our results verify that GRg3 is a promising therapeutic agent for RP treatment and shed light on its mechanism.


Asunto(s)
Ginsenósidos , Proctitis , Ratas Wistar , Animales , Ginsenósidos/farmacología , Ginsenósidos/uso terapéutico , Ratas , Proctitis/etiología , Proctitis/tratamiento farmacológico , Masculino , Traumatismos por Radiación/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Caspasa 8/metabolismo , Modelos Animales de Enfermedad
3.
Eur J Nutr ; 63(8): 2975-2986, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39231872

RESUMEN

PURPOSE: Sub-optimal food choices contribute to the risk of multiple non-communicable diseases (NCDs) which can be mitigated by improving diet quality. Food consumption patterns may partly account for variation of NCD risks in population subgroups in China. This study aimed to evaluate the risk of diet-related NCDs of observed Chinese diets, and to assess the potential reduction in NCD risks by adhering to certain diet recommendations. METHODS: Dose-response meta-analyses were used to derive relative risks between three diet-related NCDs and consumption of 15 food groups. 24-h dietary recall data of 12,809 adults from the 2011 China Health and Nutrition Survey were used to estimate the diet-related summed risks (SRs) of NCDs. Twelve Chinese provinces were aggregated into five regions, and stratified by age, gender, overweight status, education, income, and urbanicity. The Chinese Dietary Guideline-2016 (CDG-2016) and the EAT-Lancet diet were used as recommended diets. RESULTS: Associations between SRs and gender, age, educational level, income level, and urbanicity were observed. No association was found between SRs and overweight status. Both diet recommendations have lower SRs compared to observed diets among all regions. The food groups that contributed most to the variation of the SRs of diet-related NCDs in China were high consumption of red meat and refined grains, and low consumption of whole grains, fruits, and legumes. CONCLUSION: To address the heterogeneity in diet-related NCD risks, focusing on region-specific dietary practical is imperative for Chinese population, in order to propose tailored guidance to adhere to diet recommendations.


Asunto(s)
Dieta , Enfermedades no Transmisibles , Encuestas Nutricionales , Humanos , China/epidemiología , Enfermedades no Transmisibles/epidemiología , Dieta/estadística & datos numéricos , Dieta/métodos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Encuestas Nutricionales/métodos , Encuestas Nutricionales/estadística & datos numéricos , Factores de Riesgo , Anciano , Adulto Joven , Conducta Alimentaria
4.
Am J Clin Nutr ; 120(4): 846-853, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39111550

RESUMEN

BACKGROUND: Low-calorie sweetener (LCS) consumption is prevalent among lactating mothers, yet infants' exposure to LCS in human milk is not well-characterized. OBJECTIVES: Conduct a pharmacokinetic study of sucralose and acesulfame-potassium (ace-K) in mothers' milk and plasma over 72 h and in infants' plasma. METHODS: Following baseline blood and milk collection, mothers (n = 40) consumed 20 oz of diet cranberry juice containing sucralose and ace-K. Blood samples were collected from the mother 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 24, 48, and 72 h after beverage ingestion, and milk was expressed at 1, 2, 3, 4, 6, 8, 12, and 24 h postingestion. One blood sample was collected from each infant, the timing of which was determined using pharmacokinetics model-based simulation. Concentration-time profiles of LCS from the mother's plasma and milk were analyzed using noncompartmental methods. RESULTS: Ace-K rapidly entered human milk with the largest observed concentration of 373.0 (coefficient of variation 69%) ng/mL first detected 4 h following diet beverage ingestion. Sucralose appeared in human milk 1-2 h after diet beverage ingestion with the largest observed concentration of 7.2 (coefficient of variation 63%) ng/mL first detected 7 h postingestion. The mean 24-h milk to plasma ratio of ace-K was 1.75 [standard deviation (SD) 1.37] with a mean relative infant dose of 1.59% (SD 1.72%). Ace-K was detected in all infants' plasma with an mean concentration of 9.2 (SD% 14.8) ng/mL ∼6 h after maternal beverage ingestion. The mean 24-h milk to plasma ratio of sucralose was 0.15 (SD 0.06) with a mean relative infant dose of 0.04% (SD 0.02%). Sucralose was detected in only 15 infants' plasma, and the mean concentration was 5.0 (SD% 7.1) ng/mL ∼5 h after diet beverage ingestion. CONCLUSIONS: Ace-K rapidly transfers from human milk into infants' circulation whereas sucralose was detected at much lower concentrations and in some but not all infants. Future research should investigate the effects of early-life sucralose and ace-K exposure via human milk on infants' health. This trial was registered at clinicaltrials.gov as NCT05379270.


Asunto(s)
Leche Humana , Sacarosa , Edulcorantes , Tiazinas , Humanos , Leche Humana/química , Femenino , Tiazinas/farmacocinética , Tiazinas/sangre , Sacarosa/análogos & derivados , Sacarosa/farmacocinética , Adulto , Lactante , Edulcorantes/farmacocinética , Masculino , Lactancia , Adulto Joven , Madres
5.
Nutrients ; 16(16)2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39203815

RESUMEN

In mammals, nitric oxide (NO) is generated either by the nitric oxide synthase (NOS) enzymes from arginine or by the reduction of nitrate to nitrite by tissue xanthine oxidoreductase (XOR) and the microbiome and further reducing nitrite to NO by XOR or several heme proteins. Previously, we reported that skeletal muscle acts as a large nitrate reservoir in mammals, and this nitrate reservoir is systemically, as well as locally, used to generate nitrite and NO. Here, we report identifying two additional nitrate storage organs-bone and skin. We used bolus of ingested 15N-labeled nitrate to trace its short-term fluxes and distribution among organs. At baseline conditions, the nitrate concentration in femur bone samples was 96 ± 63 nmol/g, scalp skin 56 ± 22 nmol/g, with gluteus muscle at 57 ± 39 nmol/g. In comparison, plasma and liver contained 34 ± 19 nmol/g and 15 ± 5 nmol/g of nitrate, respectively. Three hours after 15N-nitrate ingestion, its concentration significantly increased in all organs, exceeding the baseline levels in plasma, skin, bone, skeletal muscle, and in liver 5-, 2.4-, 2.4-, 2.1-, and 2-fold, respectively. As expected, nitrate reduction into nitrite was highest in liver but also substantial in skin and skeletal muscle, followed by the distribution of 15N-labeled nitrite. We believe that these results underline the major roles played by skeletal muscle, skin, and bone, the three largest organs in mammals, in maintaining NO homeostasis, especially via the nitrate-nitrite-NO pathway.


Asunto(s)
Huesos , Músculo Esquelético , Nitratos , Nitritos , Isótopos de Nitrógeno , Piel , Animales , Músculo Esquelético/metabolismo , Nitratos/metabolismo , Nitratos/análisis , Piel/metabolismo , Huesos/metabolismo , Nitritos/metabolismo , Nitritos/análisis , Porcinos , Isótopos de Nitrógeno/análisis , Óxido Nítrico/metabolismo , Hígado/metabolismo , Luminiscencia , Masculino
6.
Int Heart J ; 65(4): 730-737, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39085112

RESUMEN

Sodium tanshinone IIA sulfonate (STS), which is extracted from a Chinese medicinal herb, possesses many pharmacologic functions, such as coronary dilation, anti-inflammatory properties, and antiapoptotic and antioxidant effects. It remains unknown whether STS can protect cardiomyocytes injured after radiation therapy. An in vitro Sprague-Dawley (SD) rat neonatal cardiomyocyte system was established. Primary cardiomyocytes (PCMs) from neonatal SD rats were isolated under sterile conditions. PCM cells were divided into a control group (0 Gy/hour) and 5 experimental radiation therapy groups (0.25 Gy/hour, 0.5 Gy/hour, 1 Gy/hour, 2 Gy/hour, and 4 Gy/hour). Cell viability, the content of malondialdehyde (MDA), the lactate dehydrogenase (LDH) leakage rate, and superoxide dismutase (SOD) and glutathione (GSH) activities were recorded separately in each group after 7 days of culture. Western blot was used to detect the levels of p38, caspase-3 protein, and X protein (BAX) associated with B-cell lymphoma 2 (Bcl-2) in PCMs. X-rays inhibited cell growth, decreased cell viability, and induced an oxidative stress response in PCMs. STS and SB203580 (the inhibitor of P38 mitogen-activated protein kinase pathway) alleviated X-ray-induced damage to PCMs. An enzyme-linked immunosorbent assay showed that X-rays increased the cTnT level. STS and SB203580 ameliorated the X-ray-induced increase in cTnT leakage. X-rays enhanced the expression of p38/p-p38 and caspase-3 while reducing the expression of Bcl-2/BAX in PCMs, as demonstrated by western blotting. STS and SB203580 mitigated the changes in protein expression triggered by X-ray radiation. In conclusions, STS was shown to exert significant cardioprotective, anti-inflammatory, and antioxidant effects in PCMs by inhibiting the p38 mitogen-activated protein kinase pathway.


Asunto(s)
Miocitos Cardíacos , Fenantrenos , Ratas Sprague-Dawley , Proteínas Quinasas p38 Activadas por Mitógenos , Animales , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de la radiación , Ratas , Fenantrenos/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Células Cultivadas , Animales Recién Nacidos , Supervivencia Celular/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Apoptosis/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Antioxidantes/farmacología
9.
Angew Chem Int Ed Engl ; 63(41): e202408673, 2024 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-38981860

RESUMEN

Biomaterials such as spider silk and mussel byssi are fabricated by the dynamic manipulation of intra- and intermolecular biopolymer interactions. Organisms modulate solution parameters, such as pH and ion co-solute concentration, to effect these processes. These biofabrication schemes provide a conceptual framework to develop new dynamic and responsive abiotic soft material systems. Towards these ends, the chemical diversity of readily available ionic compounds offers a broad palette to manipulate the physicochemical properties of polyelectrolytes via ion-specific interactions. In this study, we show for the first time that the ion-specific interactions of biomimetic polyelectrolytes engenders a variety of phase separation behaviors, creating dynamic thermal- and ion-responsive soft matter that exhibits a spectrum of physical properties, spanning viscous fluids to viscoelastic and viscoplastic solids. These ion-dependent characteristics are further rendered general by the merger of lysine and phenylalanine into a single, amphiphilic vinyl monomer. The unprecedented breadth, precision, and dynamicity in the reported ion-dependent phase behaviors thus introduce a broad array of opportunities for the future development of responsive soft matter; properties that are poised to drive developments in critical areas such as chemical sensing, soft robotics, and additive manufacturing.

11.
Adv Mater ; 36(36): e2402971, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39011789

RESUMEN

For multicenter-catalyzed reactions, it is important to accurately construct heterogeneous catalysts containing multiple active centers with high activity and low cost, which is more challenging compared to homogeneous catalysts because of the low activity and spatial confinement of active centers in the loaded state. Herein, a convenient protein confinement strategy is reported to locate Pd and Cu single atoms in crowding state on carbon coated alumina for promoting Sonogashira reaction, the most powerful method for constructing the acetylenic moiety in molecules. The single-atomic Pd and Cu centers take advantage in not only the maximized atomic utilization for low cost, but also the much-enhanced performance by facilitating the activation of aryl halides and alkynes. Their locally crowded dispersion brings them closer to each other, which facilitates the transmetallation process of acetylide intermediates between them. Thus, the Sonogashira reaction is drove smoothly by the obtained catalyst with a turnover frequency value of 313 h-1, much more efficiently than that by commercial Pd/C and CuI catalyst, conventional Pd and Cu nanocatalysts, and mixed Pd and Cu single-atom catalyst. The obtained catalyst also exhibits the outstanding durability in the recycling test.

12.
Nat Commun ; 15(1): 5193, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890366

RESUMEN

Multichannel meta-imaging, inspired by the parallel-processing capability of neuromorphic computing, offers considerable advancements in resolution enhancement and edge discrimination in imaging systems, extending even into the mid- to far-infrared spectrum. Currently typical multichannel infrared imaging systems consist of separating optical gratings or merging multi-cameras, which require complex circuit design and heavy power consumption, hindering the implementation of advanced human-eye-like imagers. Here, we present printable graphene plasmonic photodetector arrays driven by a ferroelectric superdomain for multichannel meta-infrared imaging with enhanced edge discrimination. The fabricated photodetectors exhibited multiple spectral responses with zero-bias operation by directly rescaling the ferroelectric superdomain instead of reconstructing the separated gratings. We also demonstrated enhanced and faster shape classification (98.1%) and edge detection (98.2%) using our multichannel infrared images compared with single-channel detectors. Our proof-of-concept photodetector arrays simplify multichannel infrared imaging systems and offer potential solutions in efficient edge detection in human-brain-type machine vision.

13.
Am J Transl Res ; 16(5): 1859-1879, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38883361

RESUMEN

OBJECTIVE: High doses of radiation, while effective at destroying tumor tissues, also result in radiation dermatitis (RD) at irradiated sites, which is one of the most common complications in cancer radiotherapy. Currently, no standardized protocols for the prevention and treatment of RD have been established in clinical practices, and severe RD can compromise treatment efficacy and reduce patients' quality of life. This systematic review and network meta-analysis (NMA) aims to compare the effectiveness of various interventions in preventing RD in patients. METHODS: As of June 2023, four databases, including PubMed, Embase, Web of Science, and the Cochrane Library, were searched, with a total of 19 interventions obtained for comparative analysis of their effectiveness in preventing RD. The Cochrane risk-of-bias tool was employed to screen literature, extract data, and appraise the quality of the studies by two researchers. Bayesian network meta-analysis (NMA) was conducted utilizing StataSE 15 and R 4.2.3. RESULTS: A total of 33 studies involving 4307 patients were included in this analysis. From the 33 studies, 19 interventions, encompassing Barrier Films and Dressings (BFD), Boron_Gel, Best supportive care, Corticosteroids_cream, Doxepin_cream, Eau Thermale Avèn_gel, Epidermal Growth Factor_cream, Hyaluronan_cream, Medicinal_Plants, Mineral_Oil, Olive oil and calcium hydroxide (OOCH), Photobiomodulation therapy, Recove_cream, Silicone_gel, Silver sulfadiazine (SSD), Timolol_Gel, Trolamine, VitD_Gel, and VitE_Gel, were retrieved and compared. The NMA results indicated that Hyaluronan_cream (SUCRA: 94.9%) was highly effective in preventing Grade 0/1 RD. Meanwhile, OOCH (SUCRA: 95.7%) demonstrated the most prominent effect in preventing ≥ Grade 2 RD. CONCLUSION: The study reveals that Hyaluronan_cream and OOCH are two promising treatments for the prevention of RD in patients undergoing radiotherapy. Future research might focus on validating the efficacy of these two therapies with large sample sizes and on identifying an optimal intervention strategy.

14.
Adv Radiat Oncol ; 9(7): 101503, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38883996

RESUMEN

Purpose: Although active spot scanning irradiation technique is theoretically superior to passive-scattered broad beam irradiation with respect to normal tissue sparing, corroborations of the clinical benefit of carbon-ion spot scanning have remained scarce. This study aims to investigate the feasibility and clinical implementation of an active spot scanning beam calculation algorithm in a homemade carbon-ion treatment planning system by comparing it with a conventional passive uniform scanning technique. Methods and Materials: Carbon-ion plans were initially formulated using spot/uniform scanning methods in 22 participants enrolled in a prospective observational clinical trial. Subsequently, 2 additional plans were designed, resulting in 3 carbon-ion plans for each participant: uniform and spot scanning with miniridge filters of 2 mm and 4 mm, respectively. Results: The findings revealed no significant differences in dose homogeneity; however, significant differences in dose conformity were found between the active and passive scanning plans. For dose drop-off outside the target volume, the average gradient index values were 1.94 (95% CI, 1.79%-2.09%), 1.87 (95% CI, 1.73%-2.01%), and 3.20 (95% CI, 2.80%-3.61%) for the miniridge filters of 2 mm and 4 mm, and uniform scanning plans, respectively. The pretreatment tumor volume was 124.7 cm3 (range, 54.2-234 cm3), and the average shrinkage observed was 38.4% (95% CI, 17.6%-59.4%). Seven participants experienced grade 1 acute toxicity, and 4 experienced grade 2 acute toxicity. However, none of the patients developed grade 3 acute toxicity. Conclusions: Increasing evidence suggests that potential clinical advantages of spot scanning delivery underlie its technical characteristics. As one among the few institutions currently using carbon-ion radiation therapy, the investigation also provides promising safety and efficacy outcomes from the initial groups of treated participants, thereby contributing to the established clinical evidence supporting the effectiveness and superiority of carbon-ion therapy.

16.
Nutrients ; 16(8)2024 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-38674845

RESUMEN

Nitrate (NO3-) obtained from the diet is converted to nitrite (NO2-) and subsequently to nitric oxide (NO) within the body. Previously, we showed that porcine eye components contain substantial amounts of nitrate and nitrite that are similar to those in blood. Notably, cornea and sclera exhibited the capability to reduce nitrate to nitrite. To gain deeper insights into nitrate metabolism in porcine eyes, our current study involved feeding pigs either NaCl or Na15NO3 and assessing the levels of total and 15N-labeled NO3-/NO2- in various ocular tissues. Three hours after Na15NO3 ingestion, a marked increase in 15NO3- and 15NO2- was observed in all parts of the eye; in particular, the aqueous and vitreous humor showed a high 15NO3- enrichment (77.5 and 74.5%, respectively), similar to that of plasma (77.1%) and showed an even higher 15NO2- enrichment (39.9 and 35.3%, respectively) than that of plasma (19.8%). The total amounts of NO3- and NO2- exhibited patterns consistent with those observed in 15N analysis. Next, to investigate whether nitrate or nitrite accumulate proportionally after multiple nitrate treatments, we measured nitrate and nitrite contents after supplementing pigs with Na15NO3 for five consecutive days. In both 15N-labeled and total nitrate and nitrite analysis, we did not observe further accumulation of these ions after multiple treatments, compared to a single treatment. These findings suggest that dietary nitrate supplementation exerts a significant influence on nitrate and nitrite levels and potentially NO levels in the eye and opens up the possibility for the therapeutic use of dietary nitrate/nitrite to enhance or restore NO levels in ocular tissues.


Asunto(s)
Suplementos Dietéticos , Nitratos , Nitritos , Animales , Nitratos/metabolismo , Porcinos , Nitritos/metabolismo , Ojo/metabolismo , Isótopos de Nitrógeno , Córnea/metabolismo , Dieta , Humor Acuoso/metabolismo , Cuerpo Vítreo/metabolismo , Óxido Nítrico/metabolismo , Alimentación Animal/análisis
17.
Nat Commun ; 15(1): 1266, 2024 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-38341401

RESUMEN

Ubiquitination, catalyzed usually by a three-enzyme cascade (E1, E2, E3), regulates various eukaryotic cellular processes. E3 ligases are the most critical components of this catalytic cascade, determining both substrate specificity and polyubiquitination linkage specificity. Here, we reveal the mechanism of a naturally occurring E3-independent ubiquitination reaction of a unique human E2 enzyme UBE2E1 by solving the structure of UBE2E1 in complex with substrate SETDB1-derived peptide. Guided by this peptide sequence-dependent ubiquitination mechanism, we developed an E3-free enzymatic strategy SUE1 (sequence-dependent ubiquitination using UBE2E1) to efficiently generate ubiquitinated proteins with customized ubiquitinated sites, ubiquitin chain linkages and lengths. Notably, this strategy can also be used to generate site-specific branched ubiquitin chains or even NEDD8-modified proteins. Our work not only deepens the understanding of how an E3-free substrate ubiquitination reaction occurs in human cells, but also provides a practical approach for obtaining ubiquitinated proteins to dissect the biochemical functions of ubiquitination.


Asunto(s)
Enzimas Ubiquitina-Conjugadoras , Ubiquitina-Proteína Ligasas , Humanos , Péptidos/metabolismo , Ubiquitina/metabolismo , Enzimas Ubiquitina-Conjugadoras/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas Ubiquitinadas/metabolismo , Ubiquitinación , Ingeniería de Proteínas
18.
Bioorg Chem ; 145: 107186, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38387394

RESUMEN

Heterotypic ubiquitin (Ub) chains have emerged as fundamental components in a wide range of cellular processes. The integrative identification of Ub-interacting proteins (readers) and Ub-modifying enzymes (writers and erasers) that selectively recognize and regulate heterotypic ubiquitination may provide crucial insights into these processes. In this study, we employed the bifunctional molecule-assisted (CAET) strategy to develop a type of disulfide bond-activated heterotypic Ub reagents, which allowed to enrich heterotypic Ub-interacting proteins and modifying enzymes simultaneously. The sequential release of readers which are non-covalently bound and writers or erasers which are covalently conjugated by using urea and reductant, respectively, combined with label-free quantitative (LFQ) MS indicated that these heterotypic Ub reagents would facilitate future investigations into functional roles played by heterotypic Ub chains.


Asunto(s)
Proteínas , Ubiquitina , Ubiquitina/metabolismo , Indicadores y Reactivos , Ubiquitinación , Proteínas/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo
19.
Appl Physiol Nutr Metab ; 49(1): 125-134, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37902107

RESUMEN

Sucralose and acesulfame-potassium consumption alters gut microbiota in rodents, with unclear effects in humans. We examined effects of three-times daily sucralose- and acesulfame-potassium-containing diet soda consumption for 1 (n = 17) or 8 (n = 8) weeks on gut microbiota composition in young adults. After 8 weeks of diet soda consumption, the relative abundance of Proteobacteria, specifically Enterobacteriaceae, increased; and, increased abundance of two Proteobacteria taxa was also observed after 1 week of diet soda consumption compared with sparkling water. In addition, three taxa in the Bacteroides genus increased following 1 week of diet soda consumption compared with sparkling water. The clinical relevance of these findings and effects of sucralose and acesulfame-potassium consumption on human gut microbiota warrant further investigation in larger studies. Clinical trial registration: NCT02877186 and NCT03125356.


Asunto(s)
Agua Carbonatada , Adulto Joven , Humanos , Proyectos Piloto , Edulcorantes/farmacología , Dieta , Potasio
20.
J Clin Endocrinol Metab ; 109(5): 1361-1370, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-37967247

RESUMEN

OBJECTIVE: Elevated rates of gluconeogenesis are an early pathogenic feature of youth-onset type 2 diabetes (Y-T2D), but targeted first-line therapies are suboptimal, especially in African American (AA) youth. We evaluated glucose-lowering mechanisms of metformin and liraglutide by measuring rates of gluconeogenesis and ß-cell function after therapy in AA Y-T2D. METHODS: In this parallel randomized clinical trial, 22 youth with Y-T2D-age 15.3 ± 2.1 years (mean ± SD), 68% female, body mass index (BMI) 40.1 ± 7.9 kg/m2, duration of diagnosis 1.8 ± 1.3 years-were randomized to metformin alone (Met) or metformin + liraglutide (Lira) (Met + Lira) and evaluated before and after 12 weeks. Stable isotope tracers were used to measure gluconeogenesis [2H2O] and glucose production [6,6-2H2]glucose after an overnight fast and during a continuous meal. ß-cell function (sigma) and whole-body insulin sensitivity (mSI) were assessed during a frequently sampled 2-hour oral glucose tolerance test. RESULTS: At baseline, gluconeogenesis, glucose production, and fasting and 2-hour glucose were comparable in both groups, though Met + Lira had higher hemoglobin A1C. Met + Lira had a greater decrease from baseline in fasting glucose (-2.0 ± 1.3 vs -0.6 ± 0.9 mmol/L, P = .008) and a greater increase in sigma (0.72 ± 0.68 vs -0.05 ± 0.71, P = .03). The change in fractional gluconeogenesis was similar between groups (Met + Lira: -0.36 ± 9.4 vs Met: 0.04 ± 12.3%, P = .9), and there were no changes in prandial gluconeogenesis or mSI. Increased glucose clearance in both groups was related to sigma (r = 0.63, P = .003) but not gluconeogenesis or mSI. CONCLUSION: Among Y-T2D, metformin with or without liraglutide improved glycemia but did not suppress high rates of gluconeogenesis. Novel therapies that will enhance ß-cell function and target the elevated rates of gluconeogenesis in Y-T2D are needed.

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