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1.
FASEB J ; 38(1): e23325, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38117486

RESUMEN

Obesity is driven by an imbalance between caloric intake and energy expenditure, causing excessive storage of triglycerides in adipose tissue at different sites around the body. Increased visceral adipose tissue (VAT) is associated with diabetes, while pericardial adipose tissue (PAT) is associated with cardiac pathology. Adipose tissue can expand either through cellular hypertrophy or hyperplasia, with the former correlating with decreased metabolic health in obesity. The aim of this study was to determine how VAT and PAT remodel in response to obesity, stress, and exercise. Here we have used the male obese Zucker rats, which carries two recessive fa alleles that result in the development of hyperphagia with reduced energy expenditure, resulting in morbid obesity and leptin resistance. At 9 weeks of age, a group of lean (Fa/Fa or Fa/fa) Zucker rats (LZR) and obese (fa/fa) Zucker rats (OZR) were treated with unpredictable chronic mild stress or exercise for 8 weeks. To determine the phenotype for PAT and VAT, tissue cellularity and gene expression were analyzed. Finally, leptin signaling was investigated further using cultured 3T3-derived adipocytes. Tissue cellularity was determined following hematoxylin and eosin (H&E) staining, while qPCR was used to examine gene expression. PAT adipocytes were significantly smaller than those from VAT and had a more beige-like appearance in both LZR and OZR. In the OZR group, VAT adipocyte cell size increased significantly compared with LZR, while PAT showed no difference. Exercise and stress resulted in a significant reduction in VAT cellularity in OZR, while PAT showed no change. This suggests that PAT cellularity does not remodel significantly compared with VAT. These data indicate that the extracellular matrix of PAT is able to remodel more readily than in VAT. In the LZR group, exercise increased insulin receptor substrate 1 (IRS1) in PAT but was decreased in the OZR group. In VAT, exercise decreased IRS1 in LZR, while increasing it in OZR. This suggests that in obesity, VAT is more responsive to exercise and subsequently becomes less insulin resistant compared with PAT. Stress increased PPAR-γ expression in the VAT but decreased it in the PAT in the OZR group. This suggests that in obesity, stress increases adipogenesis more significantly in the VAT compared with PAT. To understand the role of leptin signaling in adipose tissue remodeling mechanistically, JAK2 autophosphorylation was inhibited using 5 µM 1,2,3,4,5,6-hexabromocyclohexane (Hex) in cultured 3T3-derived adipocytes. Palmitate treatment was used to induce cellular hypertrophy. Hex blocked adipocyte hypertrophy in response to palmitate treatment but not the increase in lipid droplet size. These data suggest that leptin signaling is necessary for adipocyte cell remodeling, and its absence induces whitening. Taken together, our data suggest that leptin signaling is necessary for adipocyte remodeling in response to obesity, exercise, and psychosocial stress.


Asunto(s)
Tejido Adiposo , Leptina , Masculino , Ratas , Animales , Ratas Zucker , Pericardio , Palmitatos , Estrés Psicológico , Hipertrofia , Obesidad
2.
Bioorg Chem ; 147: 107304, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38643563

RESUMEN

Increasing the selectivity of chemotherapies by converting them into prodrugs that can be activated at the tumour site decreases their side effects and allows discrimination between cancerous and non-cancerous cells. Herein, the use of metabolic glycoengineering (MGE) to selectively label MCF-7 breast cancer cells with tetrazine (Tz) activators for subsequent activation of prodrugs containing the trans-cyclooctene (TCO) moiety by a bioorthogonal reaction is demonstrated. Three novel Tz-modified monosaccharides, Ac4ManNTz 7, Ac4GalNTz 8, and Ac4SiaTz 16, were used for expression of the Tz activator within sialic-acid rich breast cancer cells' surface glycans through MGE. Tz expression on breast cancer cells (MCF-7) was evaluated versus the non-cancerous L929 fibroblasts showing a concentration-dependant effect and excellent selectivity with ≥35-fold Tz expression on the MCF-7 cells versus the non-cancerous L929 fibroblasts. Next, a novel TCO-N-mustard prodrug and a TCO-doxorubicin prodrug were analyzed in vitro on the Tz-bioengineered cells to probe our hypothesis that these could be activated via a bioorthogonal reaction. Selective prodrug activation and restoration of cytotoxicity were demonstrated for the MCF-7 breast cancer cells versus the non-cancerous L929 cells. Restoration of the parent drug's cytotoxicity was shown to be dependent on the level of Tz expression where the Ac4ManNTz 7 and Ac4GalNTz 8 derivatives (20 µM) lead to the highest Tz expression and full restoration of the parent drug's cytotoxicity. This work suggests the feasibility of combining MGE and tetrazine ligation for selective prodrug activation in breast cancer.


Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Profármacos , Profármacos/química , Profármacos/farmacología , Profármacos/síntesis química , Humanos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/síntesis química , Femenino , Estructura Molecular , Ensayos de Selección de Medicamentos Antitumorales , Relación Estructura-Actividad , Células MCF-7 , Relación Dosis-Respuesta a Droga , Proliferación Celular/efectos de los fármacos , Ingeniería Metabólica , Supervivencia Celular/efectos de los fármacos
3.
J Enzyme Inhib Med Chem ; 38(1): 2236802, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37470394

RESUMEN

Natural α-glucosidase inhibitors from plant-based foods such as catechins offer an attractive strategy for their potential anti-diabetic effects. In this study, infusions of three different tea types (green, white, and oolong) were investigated for their total phenolic (TPC) and catechins (EGCG, ECG, EGC, and EC) content, and for their α-glucosidase inhibitory activities. We observed that the level of TPC in white tea was significantly higher compared to oolong and green tea, which suggests higher content of EGCG and ECG catechins in fresh young leaves. Our findings showed that the higher content of such catechins in the infusion of white tea well correlated with a strong inhibition of α-glucosidase, and such inhibition was demonstrated to be more effective than the FDA-approved drug acarbose. Then, we computationally explored the molecular requirements for enzyme inhibition, especially for the most active catechins EGCG and ECG, as well as their disposition/stability within the active site.


Asunto(s)
Catequina , Inhibidores de Glicósido Hidrolasas , alfa-Glucosidasas , Catequina/química , Catequina/farmacología , Fenoles , Extractos Vegetales/química , Té/química , Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/farmacología
4.
J Enzyme Inhib Med Chem ; 38(1): 2205042, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37184042

RESUMEN

Twenty-five azole compounds (P1-P25) were synthesised using regioselective base-metal catalysed and microwave-assisted approaches, fully characterised by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR), and infrared spectra (IR) analyses, and evaluated for anticancer, anti-tyrosinase, and anti-oxidant activities in silico and in vitro. P25 exhibited potent anticancer activity against cells of four skin cancer (SC) lines, with selectivity for melanoma (A375, SK-Mel-28) or non-melanoma (A431, SCC-12) SC cells over non-cancerous HaCaT-keratinocytes. Clonogenic, scratch-wound, and immunoblotting assay data were consistent with anti-proliferative results, expression profiling therewith implicating intrinsic and extrinsic apoptosis activation. In a mushroom tyrosinase inhibition assay, P14 was most potent among the compounds (half-maximal inhibitory concentration where 50% of cells are dead, IC50 15.9 µM), with activity greater than arbutin and kojic acid. Also, P6 exhibited noteworthy free radical-scavenging activity. Furthermore, in silico docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) simulations predicted prominent-phenotypic actives to engage diverse cancer/hyperpigmentation-related targets with relatively high affinities. Altogether, promising early-stage hits were identified - some with multiple activities - warranting further hit-to-lead optimisation chemistry with further biological evaluations, towards identifying new skin-cancer and skin-pigmentation renormalising agents.


Asunto(s)
Monofenol Monooxigenasa , Neoplasias Cutáneas , Humanos , Antioxidantes/farmacología , Estructura Molecular , Inhibidores Enzimáticos/química , Simulación del Acoplamiento Molecular , Simulación por Computador , Neoplasias Cutáneas/tratamiento farmacológico , Azoles , Pirazoles
5.
Molecules ; 27(15)2022 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-35897938

RESUMEN

Antiangiogenic agents attenuate tumours' growth and metastases and are therefore beneficial as an adjuvant or standalone cancer regimen. Drugs with dual antiproliferative and antiangiogenic activities can achieve anticancer efficacy and overcome acquired resistance. In this study, synthetic flavones (5a,b) with reported anticancer activity, and derivatives (4b and 6a), exhibited significant inhibition of endothelial cell tube formation (40-55%, 12 h) at 1 µM, which is comparable to sunitinib (50% inhibition at 1 µM, 48 h). Flavones (4b, 5a,b and 6a) also showed 25-37% reduction in HUVECs migration at 10 µM. In a Western blotting assay, 5a and 5b subdued VEGFR2 phosphorylation by 37% and 57%, respectively, suggesting that VEGFR2 may be their main antiangiogenic target. 5b displayed the best docking fit with VEGFR2 in an in silico study, followed by 5a, emphasizing the importance of the 7-hydroxyl group accompanied by a 4-C=S for activity. Conversely, derivatives with a 4-carbonyl moiety fitted poorly into the target's binding pocket, suggesting that their antiangiogenic activity depends on a different target. This study provides valuable insight into the Structure Activity Relationships (SAR) and modes of action of halogenated flavones with VEGFR2 and highlights their therapeutic potential as antiangiogenic/anticancer lead compounds.


Asunto(s)
Antineoplásicos , Flavonas , Inhibidores de la Angiogénesis/química , Inhibidores de la Angiogénesis/farmacología , Antineoplásicos/farmacología , Proliferación Celular , Células Endoteliales/metabolismo , Flavonas/química , Flavonas/farmacología , Flavonoides/farmacología , Fosforilación , Receptor 2 de Factores de Crecimiento Endotelial Vascular
6.
Molecules ; 27(22)2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36432019

RESUMEN

Phenolics enriched pomegranate fruit (Pomella®) and red maple leaf (Maplifa®) extracts and their major phenolic constituents have demonstrated beneficial skin effects through the protection of human skin keratinocytes from oxidative-stress-induced damage. However, their mechanisms of protection of cutaneous collagen are still unclear. Herein, the collagen protective effects of Pomella® and Maplifa®, and their major bioactive phytochemicals, namely, punicalagin (PA) and ginnalin A (GA), respectively, were evaluated using enzymatic assays including collagenase, anti-glycation and cell-based models as well as computational methods. The importance of the modulatory effects was validated at the protein level for type I collagen and matrix metalloproteinases (MMPs) using human-skin-derived keratinocytes. The synergistic collagenase inhibitory effects upon combinations of Pomella® + Maplifa® and PA + GA at a combination ratio of 1:2 and 1:1, respectively, were evaluated using their combination index (CI; a well-established assessment of synergism). Pomella® (50-400 µg/mL), Maplifa® (100-800 µg/mL), PA (50-400 µM), and GA (50-400 µM) dose-dependently inhibited collagenase activity by 26.3-86.3%, 25.7-94.0%, 26.2-94.0%, and 12.0-98.0%, respectively. The CI of the anti-collagenase activity of Pomella® and Maplifa® ranged from 0.53-0.90, while that of PA and GA (12.5/12.5 and 25/25 µM) ranged from 0.66 and 0.69, respectively, suggesting a synergistic inhibitory effect. Interestingly, in the cell-based assays by Western blotting, Pomella® and Maplifa® reduced the protein expression levels of collagen degradation enzymes (MMPs), while simultaneously increasing that of type I collagen in epidermoid carcinoma A431 cells. This is the first report to show that these extracts exert synergistic collagen protective effects. Taken together, these findings provide molecular insights into the usefulness of Pomella® and Maplifa® or their phenolics as bioactive ingredients for skin care products to slow down aging and enhance skin tone.


Asunto(s)
Acer , Granada (Fruta) , Humanos , Colágeno Tipo I , Frutas/metabolismo , Colagenasas/metabolismo , Colágeno/química , Metaloproteinasas de la Matriz/metabolismo , Fenoles/farmacología , Fenoles/química
7.
Exerc Sport Sci Rev ; 49(3): 188-196, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33831902

RESUMEN

Adipose tissue and arterial dysfunction are common in the obese state. Perivascular adipose tissue (PVAT) plays an important role in mediating arterial health, and with obesity, the PVAT dysfunction negatively affects arterial health. Exercise training exerts direct and beneficial effects on PVAT, providing an additional and novel pathway by which exercise can improve arterial health in diseased populations.


Asunto(s)
Tejido Adiposo , Obesidad , Arterias , Ejercicio Físico , Humanos , Transducción de Señal
8.
Bioorg Chem ; 107: 104595, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33450548

RESUMEN

Due to hurdles, including resistance, adverse effects, and poor bioavailability, among others linked with existing therapies, there is an urgent unmet need to devise new, safe, and more effective treatment modalities for skin cancers. Herein, a series of flavonol-based derivatives of fisetin, a plant-based flavonoid identified as an anti-tumorigenic agent targeting the mammalian targets of rapamycin (mTOR)-regulated pathways, were synthesized and fully characterized. New potential inhibitors of receptor tyrosine kinases (c-KITs), cyclin-dependent kinase-2 (CDK2), and mTOR, representing attractive therapeutic targets for melanoma and non-melanoma skin cancers (NMSCs) treatment, were identified using inverse-docking, in vitro kinase activity and various cell-based anticancer screening assays. Eleven compounds exhibited significant inhibitory activities greater than the parent molecule against four human skin cancer cell lines, including melanoma (A375 and SK-Mel-28) and NMSCs (A431 and UWBCC1), with IC50 values ranging from 0.12 to < 15 µM. Seven compounds were identified as potentially potent single, dual or multi-kinase c-KITs, CDK2, and mTOR kinase inhibitors after inverse-docking and screening against twelve known cancer targets, followed by kinase activity profiling. Moreover, the potent compound F20, and the multi-kinase F9 and F17 targeted compounds, markedly decreased scratch wound closure, colony formation, and heightened expression levels of key cancer-promoting pathway molecular targets c-Kit, CDK2, and mTOR. In addition, these compounds downregulated Bcl-2 levels and upregulated Bax and cleaved caspase-3/7/8 and PARP levels, thus inducing apoptosis of A375 and A431 cells in a dose-dependent manner. Overall, compounds F20, F9 and F17, were identified as promising c-Kit, CDK2 and mTOR inhibitors, worthy of further investigation as therapeutics, or as adjuvants to standard therapies for the control of melanoma and NMSCs.


Asunto(s)
Antineoplásicos/farmacología , Flavonoles/farmacología , Melanoma/tratamiento farmacológico , Simulación del Acoplamiento Molecular , Neoplasias Cutáneas/tratamiento farmacológico , Antineoplásicos/síntesis química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Quinasa 2 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 2 Dependiente de la Ciclina/metabolismo , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Flavonoles/síntesis química , Flavonoles/química , Humanos , Melanoma/metabolismo , Melanoma/patología , Estructura Molecular , Proteínas Proto-Oncogénicas c-kit/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-kit/metabolismo , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Relación Estructura-Actividad , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/metabolismo , Células Tumorales Cultivadas
9.
Int J Gynecol Cancer ; 31(5): 670-678, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33558421

RESUMEN

OBJECTIVE: The majority of patients with cervical cancer in Ghana present with locally advanced disease. In October 2014, high-dose rate (HDR) brachytherapy was introduced at the National Center for Radiotherapy, Accra after years of using low-dose rate (LDR) brachytherapy. The aim of this study was to compare the treatment outcomes of patients treated with LDR versus HDR brachytherapy. METHODS: Patients with cervical cancer treated from January 2008 to December 2017 were reviewed. Those with stage IB-IIIB who received chemoradiation plus brachytherapy were included in the study. Post-operative patients and those with stage IV were excluded. The study end points were local control, disease-free survival, and overall survival at 2 years. Endpoints were estimated using the Kaplan-Meier method. Comparisons between treatment groups were performed using the log-rank test and Cox proportional hazards model. RESULTS: We included 284 LDR and 136 HDR brachytherapy patients. For stages IB, IIA, IIB, IIIA and IIIB disease, the 2-year local control for LDR versus HDR brachytherapy was 63% and 61% (p=0.35), 86% and 90% (p=0.68), 86% and 88% (p=0.83), 66% and 60% (p=0.56), and 77% and 40% (p=0.005), respectively. The 2-year disease-free survival for LDR versus HDR brachytherapy was 64% and 61% (p=0.50), 81% and 69% (p=0.18), 81% and 80% (p=0.54), 62% and 33% (p=0.82), and 71% and 30% (p=0.001) for stages IB, IIA, IIB, IIIA, and IIIB, respectively. The 2-year overall survival for LDR versus HDR brachytherapy was 94% and 93% (p=0.92), 98% and 68% (p=0.21), 89% and 88% (p=0.60), and 88% and 82% (p=0.34) for stages IB, IIA, IIB, and IIIB disease, respectively. CONCLUSION: There was no difference between LDR and HDR brachytherapy in local control and disease-free survival for all stages of disease, except in stage IIIB. These findings highlight the need to refine this brachytherapy technique for this group of patients.


Asunto(s)
Adenocarcinoma/mortalidad , Braquiterapia/métodos , Carcinoma de Células Escamosas/mortalidad , Neoplasias del Cuello Uterino/mortalidad , Adenocarcinoma/terapia , Anciano , Carcinoma de Células Escamosas/terapia , Quimioradioterapia/métodos , Relación Dosis-Respuesta en la Radiación , Femenino , Ghana , Humanos , Estimación de Kaplan-Meier , Persona de Mediana Edad , Estadificación de Neoplasias , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Neoplasias del Cuello Uterino/terapia
10.
J Mol Cell Cardiol ; 141: 11-16, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32201175

RESUMEN

Determining transmural mechanical properties in the heart provides a foundation to understand physiological and pathophysiological cardiac mechanics. Although work on mechanical characterisation has begun in isolated cells and permeabilised samples, the mechanical profile of living individual cardiac layers has not been examined. Myocardial slices are 300 µm-thin sections of heart tissue with preserved cellular stoichiometry, extracellular matrix, and structural architecture. This allows for cardiac mechanics assays in the context of an intact in vitro organotypic preparation. In slices obtained from the subendocardium, midmyocardium and subepicardium of rats, a distinct pattern in transmural contractility is found that is different from that observed in other models. Slices from the epicardium and midmyocardium had a higher active tension and passive tension than the endocardium upon stretch. Differences in total myocyte area coverage, and aspect ratio between layers underlined the functional readouts, while no differences were found in total sarcomeric protein and phosphoprotein between layers. Such intrinsic heterogeneity may orchestrate the normal pumping of the heart in the presence of transmural strain and sarcomere length gradients in the in vivo heart.


Asunto(s)
Miocardio/metabolismo , Animales , Fenómenos Biomecánicos , Proteínas Portadoras/metabolismo , Cadenas Ligeras de Miosina/metabolismo , Fosforilación , Ratas Sprague-Dawley , Sarcómeros/metabolismo , Troponina/metabolismo
11.
Lipids Health Dis ; 17(1): 283, 2018 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-30545361

RESUMEN

BACKGROUND: Diabetes mellitus is a non-infectious disease that has a high prevalence worldwide. Altered level of many haematological parameters have been observed in patients with diabetes. The levels of lipids are also affected in diabetes by many factors since carbohydrate metabolism affect lipid metabolism. So far, very little work has been done linking haematological parameters and lipid profile in diabetics. The purpose of this study was therefore to evaluate the haematological parameters and lipid profiles of patients with type-2 diabetes and to correlate the results. METHOD: Three hundred and four (304) patients with type-2 diabetes with an age range of 28 to 70 years (171 males and 133 females) were recruited. About 5 ml of venous blood samples were collected from each participant after an overnight fast. A part of the blood samples was used to determine the lipid profile parameters and the other parts for the haematological parameters. The Statistical Package for Social Science (SPSS) version 21.0 and Microsoft office excel (2010) for windows were used for the statistical analysis of the data. Pearson's correlation were performed between haematological and lipid parameters. Significance was set at p < 0.05. RESULTS: The means and standard deviation of all the lipid parameters except TC showed significant difference in both males and females. There was also proportional increment in LDL-C (in males), LDL-C and Triglycerides (in females) as the age of participants increased and the ratio of TC/HDL was higher in males. There was also significant difference in all of the haematological parameters between the male and female populations. Further, a strong, significant positive correlation between RBC and lymphocytes and lipid parameters was observed. However, the correlation between platelets, haematocrit and haemoglobin and the lipid parameters was negatively significant. CONCLUSION: From the results obtained, it can be concluded that there is significant difference in lipid parameters between male and female diabetic patients. Levels of LDL-C and Triglycerides increased as the age of participants increased and the male population showed increased risk for coronary disease. Almost all of the haematological parameters examined differed significantly between the sexes. There was also, both strong positive and negative correlations between the haematological parameters and the lipid profiles.


Asunto(s)
Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/epidemiología , Metabolismo de los Lípidos , Lípidos/sangre , Adulto , Anciano , Glucemia , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Diabetes Mellitus Tipo 2/fisiopatología , Femenino , Ghana/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Triglicéridos/sangre
12.
J Med Internet Res ; 20(10): e10396, 2018 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-30282620

RESUMEN

BACKGROUND: Scaling up improved management of severe acute malnutrition has been identified as the nutrition intervention with the largest potential to reduce child mortality, but lack of operational capacity at all levels of the health system constrains scale-up. We therefore developed an interactive malnutrition eLearning course that is accessible at scale to build capacity of the health sector workforce to manage severely malnourished children according to the guidelines of the World Health Organization. OBJECTIVE: The aim of this study was to test whether the malnutrition eLearning course improves knowledge and skills of in-service and preservice health professionals in managing children with severe acute malnutrition and enables them to apply the gained knowledge and skills in patient care. METHODS: This 2-year prospective, longitudinal, cross-country, interrupted time-series study took place in Ghana, Guatemala, El Salvador, and Colombia between January 2015 and February 2017. A subset of 354 in-service health personnel from 12 hospitals and 2 Ministries of Health, 703 preservice trainees from 9 academic institutions, and 204 online users participated. Knowledge gained after training and retention over time was measured through pre- and postassessments comprising questions pertaining to screening, diagnosis, pathophysiology and treatment, and prevention of malnutrition. Comprehension, application, and integration of knowledge were tested. Changes in perception, confidence, and clinical practice were assessed through questionnaires and interviews. RESULTS: Before the course, awareness of the World Health Organization guidelines was 36.73% (389/1059) overall, and 26.3% (94/358) among in-service professionals. The mean score gain in knowledge after access to the course in 606 participants who had pre- and postassessment data was 11.8 (95% CI 10.8-12.9; P<.001)-a relative increase of 41.5%. The proportion of participants who achieved a score above the pass mark posttraining was 58.7% (356/606), compared with 18.2% (110/606) in pretraining. Of the in-service professionals, 85.9% (128/149) reported applying their knowledge by changing their clinical practice in screening, assessment, diagnosis, and management. This group demonstrated significantly increased retained knowledge 6 months after training (mean difference [SD] from preassessment of 12.1 [11.8]), retaining 65.8% (12.1/18.4) of gained knowledge from the training. Changes in the management of malnutrition were reported by trained participants, and institutional, operational, and policy changes were also found. CONCLUSIONS: The malnutrition eLearning course improved knowledge, understanding, and skills of health professionals in the diagnosis and management of children with severe acute malnutrition, and changes in clinical practice and confidence were reported following the completion of the course.


Asunto(s)
Creación de Capacidad/métodos , Instrucción por Computador/métodos , Análisis de Series de Tiempo Interrumpido/métodos , Desnutrición/terapia , Telemedicina/métodos , Niño , Femenino , Humanos , Estudios Longitudinales , Masculino , Desnutrición/patología , Estudios Prospectivos , Encuestas y Cuestionarios
13.
J Physiol ; 594(12): 3287-305, 2016 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-26847743

RESUMEN

KEY POINTS: The present study investigated the mechanism associated with impaired cardiac mechanosensing that leads to heart failure by examining the factors regulating muscle LIM protein subcellular distribution in myocytes. In myocytes, muscle LIM protein subcellular distribution is regulated by cell contractility rather than passive stretch via heme oxygenase-1 and histone deacetylase signalling. The result of the present study provide new insights into mechanotransduction in cardiac myocytes. Myocyte mechanosensitivity, as indicated by the muscle LIM protein ratio, is also correlated with cardiac function in the transition to failure in a guinea-pig model of disease. This shows that the loss mechanosensitivity plays an important role during the transition to failure in the heart. The present study provides the first indication that mechanosensing could be modified pharmacologically during the transition to heart failure. ABSTRACT: Impaired mechanosensing leads to heart failure and a decreased ratio of cytoplasmic to nuclear CSRP3/muscle LIM protein (MLP ratio) is associated with a loss of mechanosensitivity. In the present study, we tested whether passive or active stress/strain was important in modulating the MLP ratio and determined whether this correlated with heart function during the transition to failure. We exposed cultured neonatal rat myocytes to a 10% cyclic mechanical stretch at 1 Hz, or electrically paced myocytes at 6.8 V (1 Hz) for 48 h. The MLP ratio decreased by 50% (P < 0.05, n = 4) only in response to electrical pacing, suggesting impaired mechanosensitivity. Inhibition of contractility with 10 µm blebbistatin resulted in an ∼3-fold increase in the MLP ratio (n = 8, P < 0.05), indicating that myocyte contractility regulates nuclear MLP. Inhibition of histone deacetylase (HDAC) signalling with trichostatin A increased nuclear MLP following passive stretch, suggesting that HDACs block MLP nuclear accumulation. Inhibition of heme oxygenase1 (HO-1) activity with protoporphyrin IX zinc(II) blocked MLP nuclear accumulation. To examine how mechanosensitivity changes during the transition to heart failure, we studied a guinea-pig model of angiotensin II infusion (400 ng kg(-1)  min(-1) ) over 12 weeks. Using subcellular fractionation, we showed that the MLP ratio increased by 88% (n = 4, P < 0.01) during compensated hypertrophy but decreased significantly during heart failure (P < 0.001, n = 4). The MLP ratio correlated significantly with the E/A ratio (r = 0.71, P < 0.01, n = 12), a clinical measure of diastolic function. These data indicate for the first time that myocyte mechanosensitivity as indicated by the MLP ratio is regulated primarily by myocyte contractility via HO-1 and HDAC signalling.


Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Hemo-Oxigenasa 1/fisiología , Proteínas con Dominio LIM/fisiología , Proteínas Musculares/fisiología , Miocitos Cardíacos/fisiología , Angiotensina II/farmacología , Animales , Femenino , Cobayas , Hemo-Oxigenasa 1/metabolismo , Histona Desacetilasas/fisiología , Proteínas con Dominio LIM/metabolismo , Proteínas Musculares/metabolismo , Miocardio , Ratas Sprague-Dawley
14.
Int J Mol Sci ; 16(8): 19040-54, 2015 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-26287166

RESUMEN

The role and function of a given protein is dependent on its structure. In recent years, however, numerous studies have highlighted the importance of unstructured, or disordered regions in governing a protein's function. Disordered proteins have been found to play important roles in pivotal cellular functions, such as DNA binding and signalling cascades. Studying proteins with extended disordered regions is often problematic as they can be challenging to express, purify and crystallise. This means that interpretable experimental data on protein disorder is hard to generate. As a result, predictive computational tools have been developed with the aim of predicting the level and location of disorder within a protein. Currently, over 60 prediction servers exist, utilizing different methods for classifying disorder and different training sets. Here we review several good performing, publicly available prediction methods, comparing their application and discussing how disorder prediction servers can be used to aid the experimental solution of protein structure. The use of disorder prediction methods allows us to adopt a more targeted approach to experimental studies by accurately identifying the boundaries of ordered protein domains so that they may be investigated separately, thereby increasing the likelihood of their successful experimental solution.


Asunto(s)
Proteínas Intrínsecamente Desordenadas/química , Animales , Biología Computacional/métodos , Humanos , Modelos Moleculares , Conformación Proteica , Pliegue de Proteína , Programas Informáticos
15.
J Assist Reprod Genet ; 31(2): 229-39, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24305840

RESUMEN

PURPOSE: The aim of the present study was to determine whether supplementation of resveratrol, a stilbenoid antioxidant with therapeutic significance, influences goat (Capra hircus) oocyte maturation and subsequent embryonic development and expression of apoptosis and early embryonic development-related genes. METHODS: Five different concentrations of resveratrol (0.1, 0.25, 0.5, 2.0 and 5.0 µM) were used in in vitro maturation (IVM) medium. Cell tracker blue and 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) fluorescent stains were used to assay intracellular glutathione and reactive oxygen species levels in mature oocytes. Parthenogenetic activation and hand-made cloning were performed to check the developmental potential following resveratrol treatment. We used quantitative real-time PCR to analyze embryonic gene expression. RESULT: Compared to control, no significant improvement was observed in nuclear maturation in resveratrol-treated groups and at 5.0 µM concentration maturation rate decreased significantly (P < 0.05). But resveratrol treatment at the concentrations of 0.25, 0.5 µM significantly reduced intracellular ROS, and increased GSH concentrations. Oocytes treated with 0.25, 0.5 µM resveratrol when subsequently used for PA and HMC, higher extent of blastocyst yields were observed. Expression analysis of proapoptotic (Bax) gene in mature oocytes, cumulus cells, and HMC-derived blastocysts revealed lesser transcript abundances in various resveratrol-treated groups., however no change in the same was observed for antiapoptotic gene (Bcl2). Differential expression of genes associated with developmental competence and nuclear reprogramming was also observed in HMC-derived blastocysts. CONCLUSION: Our results show that resveratrol treatment at optimum concentrations (0.25 and 0.5 µM) during IVM produced beneficial microenvironment within oocytes by increasing the intracellular GSH, decreasing ROS level and this in turn, stimulated embryonic development and regulated gene expression.


Asunto(s)
Blastocisto/fisiología , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Técnicas de Maduración In Vitro de los Oocitos , Oocitos/efectos de los fármacos , Oocitos/fisiología , Partenogénesis , Estilbenos/farmacología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Blastocisto/efectos de los fármacos , Estudios de Casos y Controles , Clonación de Organismos , Células del Cúmulo/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Técnicas de Cultivo de Embriones , Femenino , Glutatión/metabolismo , Cabras , Especies Reactivas de Oxígeno/metabolismo , Resveratrol
16.
Palliat Care Soc Pract ; 18: 26323524241262327, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38911601

RESUMEN

Background: The growing burden of life-threatening illnesses and advancements in care interventions call for the intentional integration of palliative care services into existing care systems. The absence of active, functioning palliative care services in most hospitals in Ghana is a major concern. This study explored the factors influencing the integration of palliative care services in one of such institutions. Objectives: The aim of the study was to explore the institutional drivers of palliative care integration in a military health facility. Design: Exploratory qualitative study. Methods: We employed a qualitative exploratory study design situated within a constructivist paradigm. A purposive sampling method was used to select and interview 11 healthcare professionals. A semistructured interview was used to conduct face-to-face, in-depth interviews with participants between April and May 2022. A thematic data analysis was done based on the Braun and Clarke analysis process with the aid of QSR NVivo-12. Results: The six themes that describe the institutional driving factors for integrating palliative care services were cognitive restructuring, supportive logistics and infrastructure, staffing, healthcare professional skills, institutional policies and priorities, and utilization of focal persons. It was observed that a paradigm shift in the mindset of healthcare professionals and administrators was a major driver that would determine the integration of palliative care services. A cognitive restructuring will facilitate a more aggressive integration of palliative care services because logistics, staffing, and medication access will be prioritized. Conclusion: Institutions have the responsibility of aligning with the WHO policy on palliative care service access and must invest in training, staffing, prioritizing palliative care needs and policies, procurement of essential drugs, and the provision of logistics and supportive infrastructure to scale up the implementation of palliative care services.

17.
JCO Glob Oncol ; 10: e2300266, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38330274

RESUMEN

PURPOSE: To build capacity for improved treatment of locally advanced cervical cancer in Ghana, including computed tomography (CT) staging and intensity modulated radiotherapy (IMRT). MATERIALS AND METHODS: Patients with histologically confirmed cervical cancer were prospectively staged with abdominopelvic CT and ultrasound and offered the opportunity to have IMRT instead of conventional two-dimensional radiotherapy. The development of an efficient, high-quality, and safe IMRT program was facilitated by investment in new technology and comprehensive training of the interdisciplinary radiotherapy team in collaboration with a North American center of excellence. RESULTS: Of 215 patients with cervical cancer referred in 2022, 66% were able to afford CT scans and 26% were able to afford IMRT. Lymph node metastases were identified in 52% of patients by CT but in only 2% of patients by ultrasound. The use of CT resulted in 63% of patients being upstaged and changed treatment intent or radiation treatment volumes in 67% of patients. Patients who had IMRT experienced fewer acute side effects and were more likely to complete treatment as planned. CONCLUSION: It is feasible to provide state-of the-art cancer treatment with CT staging and IMRT to patients with cervical cancer in low-resource settings and achieve meaningful improvements in outcomes. It requires a broad commitment by program leadership to invest in technology and staff training. Major challenges include balancing improved clinical care with reduced patient throughput when radiation treatment capacity is constrained, and with the additional cost in the absence of universal health coverage.


Asunto(s)
Radioterapia de Intensidad Modulada , Neoplasias del Cuello Uterino , Femenino , Humanos , Radioterapia de Intensidad Modulada/efectos adversos , Radioterapia de Intensidad Modulada/métodos , Neoplasias del Cuello Uterino/diagnóstico por imagen , Neoplasias del Cuello Uterino/radioterapia , Ghana , Tomografía Computarizada por Rayos X/métodos , Dosificación Radioterapéutica
18.
Chem Biol Drug Des ; 103(1): e14418, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38230791

RESUMEN

Melanoma and nonmelanoma skin cancers are among the most prevalent and most lethal forms of skin cancers. To identify new lead compounds with potential anticancer properties for further optimization, in vitro assays combined with in-silico target fishing and docking have been used to identify and further map out the antiproliferative and potential mode of action of molecules from a small library of compounds previously prepared in our laboratory. From screening these compounds in vitro against A375, SK-MEL-28, A431, and SCC-12 skin cancer cell lines, 35 displayed antiproliferative activities at the micromolar level, with the majority being primarily potent against the A431 and SCC-12 squamous carcinoma cell lines. The most active compounds 11 (A431: IC50 = 5.0 µM, SCC-12: IC50 = 2.9 µM, SKMEL-28: IC50 = 4.9 µM, A375: IC50 = 6.7 µM) and 13 (A431: IC50 = 5.0 µM, SCC-12: IC50 = 3.3 µM, SKMEL-28: IC50 = 13.8 µM, A375: IC50 = 17.1 µM), significantly and dose-dependently induced apoptosis of SCC-12 and SK-MEL-28 cells, as evidenced by the suppression of Bcl-2 and upregulation of Bax, cleaved caspase-3, caspase-9, and PARP protein expression levels. Both agents significantly reduced scratch wound healing, colony formation, and expression levels of deregulated cancer molecular targets including RSK/Akt/ERK1/2 and S6K1. In silico target prediction and docking studies using the SwissTargetPrediction web-based tool suggested that CDK8, CLK4, nuclear receptor ROR, tyrosine protein-kinase Fyn/LCK, ROCK1/2, and PARP, all of which are dysregulated in skin cancers, might be prospective targets for the two most active compounds. Further validation of these targets by western blot analyses, revealed that ROCK/Fyn and its associated Hedgehog (Hh) pathways were downregulated or modulated by the two lead compounds. In aggregate, these results provide a strong framework for further validation of the observed activities and the development of a more comprehensive structure-activity relationship through the preparation and biological evaluation of analogs.


Asunto(s)
Antineoplásicos , Melanoma , Neoplasias Cutáneas , Humanos , Melanoma/tratamiento farmacológico , Melanoma/patología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Proteínas Hedgehog/metabolismo , Neoplasias Cutáneas/tratamiento farmacológico , Apoptosis , Relación Estructura-Actividad , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Ensayos de Selección de Medicamentos Antitumorales , Proliferación Celular , Línea Celular Tumoral , Estructura Molecular , Quinasas Asociadas a rho/metabolismo
19.
Am J Physiol Heart Circ Physiol ; 304(10): H1302-13, 2013 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-23504181

RESUMEN

Prolonged hemodynamic load as a result of hypertension eventually leads to maladaptive cardiac adaptation and heart failure. The signaling pathways that underlie these changes are still poorly understood. The adaptive response to mechanical load is mediated by mechanosensors that convert the mechanical stimuli into a biological response. We examined the effect of cyclic mechanical stretch on myocyte adaptation using neonatal rat ventricular myocytes with 10% (adaptive) or 20% (maladaptive) maximum strain at 1 Hz for 48 h to mimic in vivo mechanical stress. Cells were also treated with and without nitro-L-arginine methyl ester (L-NAME), a general nitric oxide synthase (NOS) inhibitor to suppress NO production. Maladaptive 20% mechanical stretch led to a significant loss of intact sarcomeres that were rescued by L-NAME (P < 0.05; n ≥ 5 cultures). We hypothesized that the mechanism was through NO-induced alteration of myocyte gene expression. L-NAME upregulated the mechanosensing proteins muscle LIM protein (MLP; by 100%; P < 0.05; n = 5 cultures) and lipoma preferred partner (LPP), a novel cardiac protein (by 80%; P < 0.05; n = 4 cultures). L-NAME also significantly altered the subcellular localization of LPP and MLP in a manner that favored growth and adaptation. These findings suggest that NO participates in stretch-mediated adaptation. The use of isoform selective NOS inhibitors indicated a complex interaction between inducible NOS and neuronal NOS isoforms regulate gene expression. LPP knockdown by small intefering RNA led to formation of α-actinin aggregates and Z bodies showing that myofibrillogenesis was impaired. There was an upregulation of E3 ubiquitin ligase (MUL1) by 75% (P < 0.05; n = 5 cultures). This indicates that NO contributes to stretch-mediated adaptation via the upregulation of proteins associated with mechansensing and myofibrillogenesis, thereby presenting potential therapeutic targets during the progression of heart failure.


Asunto(s)
Expresión Génica/fisiología , Proteínas con Dominio LIM/fisiología , Proteínas de Microfilamentos/fisiología , Desarrollo de Músculos/fisiología , Miocitos Cardíacos/fisiología , Óxido Nítrico/fisiología , Proteínas Oncogénicas/fisiología , Actinina/metabolismo , Actinina/fisiología , Animales , Western Blotting , Células Cultivadas , Inhibidores Enzimáticos/farmacología , Expresión Génica/efectos de los fármacos , Expresión Génica/genética , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Proteínas de Microfilamentos/genética , Desarrollo de Músculos/efectos de los fármacos , Desarrollo de Músculos/genética , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa/metabolismo , Proteínas Oncogénicas/genética , ARN Interferente Pequeño/genética , Ratas , Ratas Sprague-Dawley , Sarcómeros/fisiología , Fracciones Subcelulares/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/fisiología
20.
RSC Med Chem ; 14(8): 1537-1548, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37593579

RESUMEN

Selective prodrug activation at a tumor site is crucial to maximise the efficiency of chemotherapy approaches and minimise side effects due to off-site activation. In this paper, a new prodrug activation strategy is reported based on the bioorthogonal Staudinger reaction. The feasibility of this prodrug activation strategy was initially demonstrated using 9-azido sialic acid 4 as a trigger and two novel triphenylphosphine-modified N-mustard-PRO 10 and doxorubicin-PRO 12 prodrugs in an HPLC-monitored release study. Then, the azide reporter group was introduced on cancer cells' surfaces through metabolic glycoengineering of sialic acid-rich surface glycans using azide-modified monosaccharides (9-azido sialic acid 4, tetra-O-acetylated-9-azido sialic acid 5 and tetra-O-acetyl azidomannosamine). Next, the N-mustard-PRO 10 and doxorubicin-PRO 12 prodrugs were employed in vitro with the bioengineered cells, and activation of the prodrugs, which allowed selective release of the cytotoxic moiety at the tumour cell, was assessed. Release of the parent drugs from the prodrugs was shown to be dependent on the level of metabolic labelling, where tetra-O-acetyl azidomannosamine allowed the highest level of azide reporter generation in tumor cells and led to full recovery of the parent cytotoxic drug's potency. The selectivity of azide expression on breast cancer MCF-7 cells versus normal fibroblast L929 cells was also probed, with the 9-azido sialic acid and tetra-O-acetylated-9-azido sialic acid showing ∼17-fold higher azide expression on the former. Taken together, these data demonstrate the feasibility of the Staudinger reaction for selective activation of prodrugs targeted to the MCF-7 breast cancer cells.

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