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1.
BMJ Open ; 14(1): e074858, 2024 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-38176874

RESUMEN

INTRODUCTION: Sarcopenia is characterised by age-related loss of skeletal muscle and function and is associated with risks of adverse outcomes. The prevalence of sarcopenia increases due to ageing population and effective interventions is in need. Previous studies showed that ß-hydroxy ß-methylbutyrate (HMB) supplement and vibration treatment (VT) enhanced muscle quality, while the coapplication of the two interventions had further improved muscle mass and function in sarcopenic mice model. This study aims to investigate the efficacy of this combination treatment in combating sarcopenia in older people. The findings of this study will demonstrate the effect of combination treatment as an alternative for managing sarcopenia. METHODS AND ANALYSIS: In this single-blinded randomised controlled trial, subjects will be screened based on the Asian Working Group for Sarcopenia (AWGS) 2019 definition. 200 subjects who are aged 65 or above and identified sarcopenic according to the AWGS algorithm will be recruited. They will be randomised to one of the following four groups: (1) Control+ONS; (2) HMB+ONS; (3) VT+ONS and (4) HMB+VT + ONS, where ONS stands for oral nutritional supplement. ONS will be taken in the form of protein formular once/day; HMB supplements will be 3 g/day; VT (35 Hz, 0.3 g, where g=gravitational acceleration) will be received for 20 mins/day and at least 3 days/week. The primary outcome assessments are muscle strength and function. Subjects will be assessed at baseline, 3-month and 6-month post treatment. ETHICS AND DISSEMINATION: This study was approved by Joint CUHK-NTEC (The Chinese University of Hong Kong and New Territories East Cluster) Clinical Research Management Office (Ref: CRE-2022.223-T) and conformed to the Declaration of Helsinki. Trial results will be published in peer-reviewed journals and disseminated at academic conferences. TRIAL REGISTRATION NUMBER: NCT05525039.


Asunto(s)
Sarcopenia , Animales , Ratones , Humanos , Anciano , Sarcopenia/complicaciones , Músculo Esquelético , Fuerza Muscular , Envejecimiento , Hong Kong , Suplementos Dietéticos , Ensayos Clínicos Controlados Aleatorios como Asunto
2.
SLAS Discov ; 29(1): 40-51, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37714432

RESUMEN

Surface plasmon resonance (SPR) biosensor methods are ideally suited for fragment-based lead discovery.  However, generally applicable experimental procedures and detailed protocols are lacking, especially for structurally or physico-chemically challenging targets or when tool compounds are not available. Success depends on accounting for the features of both the target and the chemical library, purposely designing screening experiments for identification and validation of hits with desired specificity and mode-of-action, and availability of orthogonal methods capable of confirming fragment hits. The range of targets and libraries amenable to an SPR biosensor-based approach for identifying hits is considerably expanded by adopting multiplexed strategies, using multiple complementary surfaces or experimental conditions. Here we illustrate principles and multiplexed approaches for using flow-based SPR biosensor systems for screening fragment libraries of different sizes (90 and 1056 compounds) against a selection of challenging targets. It shows strategies for the identification of fragments interacting with 1) large and structurally dynamic targets, represented by acetyl choline binding protein (AChBP), a Cys-loop receptor ligand gated ion channel homologue, 2) targets in multi protein complexes, represented by lysine demethylase 1 and a corepressor (LSD1/CoREST), 3) structurally variable or unstable targets, represented by farnesyl pyrophosphate synthase (FPPS), 4) targets containing intrinsically disordered regions, represented by protein tyrosine phosphatase 1B  (PTP1B), and 5) aggregation-prone proteins, represented by an engineered form of human tau  (tau K18M). Practical considerations and procedures accounting for the characteristics of the proteins and libraries, and that increase robustness, sensitivity, throughput and versatility are highlighted. The study shows that the challenges for addressing these types of targets is not identification of potentially useful fragments per se, but establishing methods for their validation and evolution into leads.


Asunto(s)
Técnicas Biosensibles , Resonancia por Plasmón de Superficie , Humanos , Resonancia por Plasmón de Superficie/métodos , Bibliotecas de Moléculas Pequeñas/farmacología , Proteínas , Proteínas Portadoras
3.
Concussion ; 8(3): CNC107, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37691851

RESUMEN

Aim: To report improvements in post-concussion syndrome and concussion incidence following cervical spinal alignment correction. Case presentation: A 27-year-old professional rugby player with 20 documented concussions presented with abnormal cervical spinal alignment and post-concussion syndrome. After 30 sessions of cervical rehabilitation, health outcomes improved. Post-treatment radiographs showed improved cervical lordosis from -13.5° to -37.4° (ideal is -42°) and right head translation from -22.7 to -11.3 mm (ideal is 0 mm). 2-year follow-up radiographs and 6-year follow-up health outcomes showed post-treatment improvements were maintained. The patient reported two documented concussions in the 6 years following treatment while maintaining the same lifestyle and professional rugby career. Conclusion: Correction of abnormal cervical spinal alignment may help athletes with post-concussion syndrome and reduce risk of concussion.


A 27-year-old male professional rugby player with a 6-year history of 20 documented concussions presented with severe neck and headache pain and disability. X-rays of his neck were taken to measure spinal alignment and posture. Also, neck and headache pain, disability and quality-of-life measures were assessed. After 30 treatment sessions of Chiropractic BioPhysics® (CBP®) neck spinal alignment and posture rehabilitation, neck and headache pain and disability and quality-of-life improved. X-rays showed improved spinal alignment and posture in his neck. Follow-up x-rays 2 years after treatment showed that the improvements to his neck spinal alignment and posture were maintained. Follow-up assessment 6 years after treatment showed that the post-treatment improvements in in neck and headache pain and disability and quality of life were maintained. Additionally, the patient reported only two documented concussions in the 6 years following treatment maintaining the same lifestyle and competing as a professional rugby player at the same level, position and playing time. This is the first documented improvement in post-concussion syndrome and decreased concussion occurrence following correction of neck spinal alignment and posture. Correction of neck spinal alignment and posture allows the spine to function as a healthy shock absorber and increases its ability to decrease stress transferred to the brain from trauma responsible for concussions and may reduce the risk of concussions.

4.
Elife ; 122023 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-37272417

RESUMEN

Mitochondrial ATP production in ventricular cardiomyocytes must be continually adjusted to rapidly replenish the ATP consumed by the working heart. Two systems are known to be critical in this regulation: mitochondrial matrix Ca2+ ([Ca2+]m) and blood flow that is tuned by local cardiomyocyte metabolic signaling. However, these two regulatory systems do not fully account for the physiological range of ATP consumption observed. We report here on the identity, location, and signaling cascade of a third regulatory system -- CO2/bicarbonate. CO2 is generated in the mitochondrial matrix as a metabolic waste product of the oxidation of nutrients. It is a lipid soluble gas that rapidly permeates the inner mitochondrial membrane and produces bicarbonate in a reaction accelerated by carbonic anhydrase. The bicarbonate level is tracked physiologically by a bicarbonate-activated soluble adenylyl cyclase (sAC). Using structural Airyscan super-resolution imaging and functional measurements we find that sAC is primarily inside the mitochondria of ventricular cardiomyocytes where it generates cAMP when activated by bicarbonate. Our data strongly suggest that ATP production in these mitochondria is regulated by this cAMP signaling cascade operating within the inter-membrane space by activating local EPAC1 (Exchange Protein directly Activated by cAMP) which turns on Rap1 (Ras-related protein-1). Thus, mitochondrial ATP production is increased by bicarbonate-triggered sAC-signaling through Rap1. Additional evidence is presented indicating that the cAMP signaling itself does not occur directly in the matrix. We also show that this third signaling process involving bicarbonate and sAC activates the mitochondrial ATP production machinery by working independently of, yet in conjunction with, [Ca2+]m-dependent ATP production to meet the energy needs of cellular activity in both health and disease. We propose that the bicarbonate and calcium signaling arms function in a resonant or complementary manner to match mitochondrial ATP production to the full range of energy consumption in ventricular cardiomyocytes.


Asunto(s)
Calcio , AMP Cíclico , Calcio/metabolismo , AMP Cíclico/metabolismo , Bicarbonatos/metabolismo , Adenilil Ciclasas/metabolismo , Dióxido de Carbono/metabolismo , Miocitos Cardíacos/metabolismo , Calcio de la Dieta , Señalización del Calcio/fisiología , Adenosina Trifosfato/metabolismo
5.
Prog Biophys Mol Biol ; 177: 185-201, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36481271

RESUMEN

Bioelectricity plays an essential role in the structural and functional organization of biological organisms. In this first article of our three-part series, we summarize the importance of bioelectricity for the basic structural level of biological organization, i.e. from the subcellular level (charges, ion channels, molecules and cell organelles) to cells.


Asunto(s)
Fenómenos Electrofisiológicos , Canales Iónicos , Orgánulos
6.
Elife ; 112022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35642964

RESUMEN

The KV7.4 and KV7.5 subtypes of voltage-gated potassium channels play a role in important physiological processes such as sound amplification in the cochlea and adjusting vascular smooth muscle tone. Therefore, the mechanisms that regulate KV7.4 and KV7.5 channel function are of interest. Here, we study the effect of polyunsaturated fatty acids (PUFAs) on human KV7.4 and KV7.5 channels expressed in Xenopus oocytes. We report that PUFAs facilitate activation of hKV7.5 by shifting the V50 of the conductance versus voltage (G(V)) curve toward more negative voltages. This response depends on the head group charge, as an uncharged PUFA analogue has no effect and a positively charged PUFA analogue induces positive V50 shifts. In contrast, PUFAs inhibit activation of hKV7.4 by shifting V50 toward more positive voltages. No effect on V50 of hKV7.4 is observed by an uncharged or a positively charged PUFA analogue. Thus, the hKV7.5 channel's response to PUFAs is analogous to the one previously observed in hKV7.1-7.3 channels, whereas the hKV7.4 channel response is opposite, revealing subtype-specific responses to PUFAs. We identify a unique inner PUFA interaction site in the voltage-sensing domain of hKV7.4 underlying the PUFA response, revealing an unconventional mechanism of modulation of hKV7.4 by PUFAs.


In order to carry out their roles in the body, cells need to send and receive electrical signals. They can do this by allowing ions to move in and out through dedicated pore-like structures studded through their membrane. These channels are specific to one type of ions, and their activity ­ whether they open or close ­ is carefully controlled. In humans, defective ion channels are associated with conditions such as irregular heartbeats, epileptic seizures or hearing loss. Research has identified molecules known as polyunsaturated fatty acids as being able to control the activity of certain members of the KV7 family of potassium ion channels. The KV7.1 and KV7.2/7.3 channels are respectively present in the heart and the brain; KV7.4 is important for hearing, while KV7.5 plays a key role in regulating muscle tone in blood vessels. Polyunsaturated fatty acids can activate KV7.1 and KV7.2/7.3 but their impact on KV7.4 and KV7.5 remains unclear. Frampton et al. explored this question by studying human KV7.4 and KV7.5 channels expressed in frog egg cells. This showed that fatty acids activated KV7.5 (as for KV7.1 and KV7.2/7.3), but that they reduced the activity of KV7.4. Closely examining the structure of KV7.4 revealed that the fatty acids were binding to a different region compared to the other KV7 channels. When this site was made inaccessible, fatty acids increased the activity of KV7.4, just as for the rest of the family. These results may help to understand the role of polyunsaturated fatty acids in the body. In addition, knowing how these molecules interact with channels in the same family will be useful for optimising a drug's structure to avoid side effects. However, further research will be needed to understand the broader impact in a more complex biological organism.


Asunto(s)
Canales de Potasio con Entrada de Voltaje , Ácidos Grasos Insaturados/farmacología , Canales de Potasio con Entrada de Voltaje/fisiología
7.
J Radiol Case Rep ; 16(2): 21-38, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35586358

RESUMEN

Objective: Discuss non-surgical spinal rehabilitation for a 27-year-old male with thoracic and lumbosacral spondylolistheses. A selective literature review and discussion are provided. Clinical Features: A 27-year-old male presented with severe, 8/10 mid and low back pain. Initial lateral thoracic and lumbar x-rays revealed grade 1 spondylolistheses at T9-T10 and L5-S1 measuring -5.3 mm and -6.8 mm. Interventions and Outcomes: The patient completed 60 sessions of Mirror Image® spinal adjustments, exercises, and traction over 30 weeks. Post-treatment x-rays showed correction in translations at T9-T10 and L5-S1 from -5.3 mm to 0.0 mm and -6.8 mm to -1.0 mm, within normal limits. 1-year follow-up x-rays showed maintained correction. Conclusions: This case is the first documented evidence of non-surgical or chiropractic treatment for thoracic and lumbosacral spondylolistheses where spinal alignment was corrected. More research is needed to investigate the clinical implications and applications.


Asunto(s)
Luxaciones Articulares , Dolor de la Región Lumbar , Fusión Vertebral , Espondilolistesis , Adulto , Estudios de Seguimiento , Humanos , Dolor de la Región Lumbar/diagnóstico por imagen , Dolor de la Región Lumbar/etiología , Dolor de la Región Lumbar/terapia , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Masculino , Calidad de Vida , Estudios Retrospectivos , Espondilolistesis/diagnóstico por imagen , Espondilolistesis/terapia
8.
Front Microbiol ; 13: 876611, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35547117

RESUMEN

Melanin is one of the most studied virulence factors in pathogenic fungi. This pigment protects them from a series of both environmental and host stressors. Among basidiomycetes, Cryptococcus neoformans and Trichosporon asahii are known to produce melanin in the presence of phenolic precursors. Other species from the Trichosporonaceae family also produce this pigment, but the extent to this production among the clinically relevant species is unknown. For this reason, the aim of this study was to verify the production of melanin by different Trichosporonaceae species of clinical interest and to compare their pigments with the ones from C. neoformans and T. asahii, which are more prevalent in human infections. Melanin was produced in a minimal medium supplemented with 1 mM L-dihydroxyphenylalanine (L-DOPA). Pigment was evaluated using scanning electron microscopy, Zeta potential measurements, and energy-dispersive X-ray spectroscopy. It was found that, besides C. neoformans and T. asahii, Trichosporon japonicum, Apiotrichum montevideense, Trichosporon inkin, Trichosporon faecale, Cutaneotrichosporon debeurmannianum, and Cutaneotrichosporon arboriformis also produce melanin-like particles in the presence of L-DOPA. Melanin particles have negative charge and are smaller than original cells. Variations in color, fluorescence, and chemical composition was noticed between the studied strains. All melanins presented carbon, oxygen, sodium, and potassium in their composition. Melanins from the most pathogenic species also presented iron, zinc, and copper, which are important during parasitism. Biophysical properties of these melanins can confer to the Trichosporonaceae adaptive advantages to both parasitic and environmental conditions of fungal growth.

9.
Biochem Mol Biol Educ ; 50(2): 181-192, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35050536

RESUMEN

In an upper-division interdisciplinary laboratory experiment, students use Raman spectroscopy to highlight how the overall structure and conformational order of lipid bilayers can be influenced by their individual phospholipid composition. Students prepare a supported lipid bilayer, as a model cell membrane, by spreading liposomes made of various phospholipids on a solid support. The characterization of phospholipid bilayers, a major component of cellular membranes, can advance our fundamental understanding of important biological phenomena, with significant implications in various fields including drug delivery and development. We use Raman spectroscopy as an analytical tool to investigate the structural and packing properties of model cell membranes. The spectral frequency, intensity, and line-width of lipid Raman bands are extremely sensitive to structural alterations. This experimental module effectively exposes students to the fundamentals of Raman spectroscopy and teaches students the importance of interdisciplinary education as they integrate concepts from chemical structure, molecular interactions, and analytical spectroscopic techniques to gain a more holistic understanding of biological membrane properties.


Asunto(s)
Fosfolípidos , Espectrometría Raman , Membrana Celular/metabolismo , Humanos , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Liposomas/química , Fosfolípidos/química
10.
Proc Natl Acad Sci U S A ; 119(3)2022 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-35022230

RESUMEN

Accurate knowledge of RNA hybridization is essential for understanding RNA structure and function. Here we mechanically unzip and rezip a 2-kbp RNA hairpin and derive the 10 nearest-neighbor base pair (NNBP) RNA free energies in sodium and magnesium with 0.1 kcal/mol precision using optical tweezers. Notably, force-distance curves (FDCs) exhibit strong irreversible effects with hysteresis and several intermediates, precluding the extraction of the NNBP energies with currently available methods. The combination of a suitable RNA synthesis with a tailored pulling protocol allowed us to obtain the fully reversible FDCs necessary to derive the NNBP energies. We demonstrate the equivalence of sodium and magnesium free-energy salt corrections at the level of individual NNBP. To characterize the irreversibility of the unzipping-rezipping process, we introduce a barrier energy landscape of the stem-loop structures forming along the complementary strands, which compete against the formation of the native hairpin. This landscape correlates with the hysteresis observed along the FDCs. RNA sequence analysis shows that base stacking and base pairing stabilize the stem-loops that kinetically trap the long-lived intermediates observed in the FDC. Stem-loops formation appears as a general mechanism to explain a wide range of behaviors observed in RNA folding.


Asunto(s)
Conformación de Ácido Nucleico , Pliegue del ARN , Fenómenos Biomecánicos , Magnesio/química , ARN/química , Sodio/química , Termodinámica
11.
STAR Protoc ; 2(4): 100979, 2021 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-34877549

RESUMEN

The mitochondrial calcium uniporter, which mediates mitochondrial Ca2+ uptake, regulates key cellular functions, including intracellular Ca2+ signaling, cell-fate determination, and mitochondrial bioenergetics. Here, we describe two complementary strategies to quantify the uniporter's transport activity. First, we detail a mitochondrial Ca2+ radionuclide uptake assay in cultured cell lines. Second, we describe electrophysiological recordings of the uniporter expressed in Xenopus oocytes. These approaches enable a detailed kinetic analysis of the uniporter to link its molecular properties to physiological functions. For complete details on the use and execution of this protocol, please refer to Tsai and Tsai (2018) and Phillips et al. (2019).


Asunto(s)
Canales de Calcio , Calcio/metabolismo , Electrofisiología/métodos , Oocitos , Animales , Canales de Calcio/análisis , Canales de Calcio/genética , Canales de Calcio/metabolismo , Técnicas de Cultivo de Célula , Línea Celular , Oocitos/citología , Oocitos/metabolismo , Técnicas de Placa-Clamp , Xenopus
12.
Elife ; 102021 12 24.
Artículo en Inglés | MEDLINE | ID: mdl-34951590

RESUMEN

Transition metals, such as zinc, are essential micronutrients in all organisms, but also highly toxic in excessive amounts. Heavy-metal transporting P-type (PIB) ATPases are crucial for homeostasis, conferring cellular detoxification and redistribution through transport of these ions across cellular membranes. No structural information is available for the PIB-4-ATPases, the subclass with the broadest cargo scope, and hence even their topology remains elusive. Here, we present structures and complementary functional analyses of an archetypal PIB-4-ATPase, sCoaT from Sulfitobacter sp. NAS14-1. The data disclose the architecture, devoid of classical so-called heavy-metal-binding domains (HMBDs), and provide fundamentally new insights into the mechanism and diversity of heavy-metal transporters. We reveal several novel P-type ATPase features, including a dual role in heavy-metal release and as an internal counter ion of an invariant histidine. We also establish that the turnover of PIB-ATPases is potassium independent, contrasting to many other P-type ATPases. Combined with new inhibitory compounds, our results open up for efforts in for example drug discovery, since PIB-4-ATPases function as virulence factors in many pathogens.


Heavy metals such as zinc and cobalt are toxic at high levels, yet most organisms need tiny amounts for their cells to work properly. As a result, proteins studded through the cell membrane act as gatekeepers to finetune import and export. These proteins are central to health and disease; their defect can lead to fatal illnesses in humans, and they also help bacteria infect other organisms. Despite their importance, little is known about some of these metal-export proteins. This is particularly the case for PIB-4-ATPases, a subclass found in plants and bacteria and which includes, for example, a metal transporter required for bacteria to cause tuberculosis. Intricate knowledge of the three-dimensional structure of these proteins would help to understand how they select metals, shuttle the compounds in and out of cells, and are controlled by other cellular processes. To reveal this three-dimensional organisation, Grønberg et al. used X-ray diffraction, where high-energy radiation is passed through crystals of protein to reveal the positions of atoms. They focused on a type of PIB-4-ATPases found in bacteria as an example. The work showed that the protein does not contain the metal-binding regions seen in other classes of metal exporters; however, it sports unique features that are crucial for metal transport such as an adapted pathway for the transport of zinc and cobalt across the membrane. In addition, Grønberg et al. tested thousands of compounds to see if they could block the activity of the protein, identifying two that could kill bacteria. This better understanding of how PIB-4-ATPases work could help to engineer plants capable of removing heavy metals from contaminated soils, as well as uncover new compounds to be used as antibiotics.


Asunto(s)
Iones/metabolismo , Metales Pesados/metabolismo , ATPasas Tipo P/química , ATPasas Tipo P/metabolismo , Rhodobacteraceae/enzimología , Sitios de Unión , Transporte Biológico , Proteínas de Transporte de Catión/metabolismo , Modelos Moleculares , ATPasas Tipo P/clasificación , Conformación Proteica , Rhodobacteraceae/clasificación , Zinc/metabolismo
13.
Curr Top Med Chem ; 21(13): 1099-1112, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34348623

RESUMEN

Fragment-Based Drug Discovery (FBDD) is a strategy to develop potent lead molecules and is frequently used in drug discovery projects of the pharmaceutical industry. This method starts from identifying a small-molecule fragment, which usually binds weakly to the target and follows with a hit-to-lead step in which the fragment is grown into potent molecules that bind tightly to the target to affect its function. Quite a few drugs and compounds in clinical trials are developed using this approach, making FBDD a powerful strategy in drug discovery. FBDD can be applied to multiple targets and the hit rate in screening can be used in target druggability assessment. In this minireview, we provide a summary of the development of FBDD. In addition to giving a brief summary of the methods used in fragment screening, we highlight some methods that are critical in fragment growth. Biophysical methods and careful chemical modification of the fragments are the key elements in FBDD. We show several strategies that can be utilized in FBDD. We emphasize that NMR spectroscopy such as 19F-NMR and 1H-5N-HSQC experiment and X-ray crystallography are important in FBDD due to their roles in fragment screening and understanding the binding modes of the fragment hits, which provides a strategy for fragment growth.


Asunto(s)
Descubrimiento de Drogas , Preparaciones Farmacéuticas/química , Cristalografía por Rayos X , Evaluación Preclínica de Medicamentos , Humanos , Modelos Moleculares
14.
Adv Healthc Mater ; 10(18): e2100636, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34235891

RESUMEN

Plasmonic photothermal therapy (PPTT) using gold nanoparticles (AuNPs) has shown great potential for use in selective tumor treatment, because the AuNPs can generate destructive heat preferentially upon irradiation. However, PPTT using AuNPs has not been added to practice, owing to insufficient heating methods and tissue temperature measurement techniques, leading to unreliable and inaccurate treatments. Because the photothermal properties of AuNPs vary with laser power, particle optical density, and tissue depth, the accurate prediction of heat generation is indispensable for clinical treatment. In this report, bioprinted 3D complex tissue constructs comprising processed gel obtained from porcine skin and human decellularized adipose tissue are presented for characterization of the photothermal properties of gold nanorods (AuNRs) having an aspect ratio of 3.7 irradiated by a near-infrared laser. Moreover, an analytical function is suggested for achieving PPTT that can cause thermal damage selectively on early-stage human breast cancer by regulating the heat generation of the AuNRs in the tissue.


Asunto(s)
Neoplasias de la Mama , Nanopartículas del Metal , Nanotubos , Neoplasias de la Mama/terapia , Línea Celular Tumoral , Femenino , Oro , Humanos , Nanopartículas del Metal/uso terapéutico , Fototerapia
15.
eNeuro ; 8(4)2021.
Artículo en Inglés | MEDLINE | ID: mdl-34131060

RESUMEN

Substantia nigra pars compacta (SNc) dopaminergic (DA) neurons display a peculiar electrical phenotype characterized in vitro by a spontaneous tonic regular activity (pacemaking activity), a broad action potential (AP) and a biphasic postinhibitory response. The transient A-type current (IA) is known to play a crucial role in this electrical phenotype, and so far, this current was considered to be carried exclusively by Kv4.3 potassium channels. Using Kv4.3-/- transgenic mice, we demonstrate that the constitutive loss of this channel is associated with increased exploratory behavior and impaired motor learning at the behavioral level. Consistently, it is also associated with a lack of compensatory changes in other ion currents at the cellular level. Using antigen retrieval (AR) immunohistochemistry, we then demonstrate that Kv4.2 potassium channels are also expressed in SNc DA neurons, although their contribution to IA appears significant only in a minority of neurons (∼5-10%). Using correlative analysis on recorded electrophysiological parameters and multicompartment modeling, we then demonstrate that, rather than its conductance level, IA gating kinetics (inactivation time constant) appear as the main biophysical property defining postinhibitory rebound delay and pacemaking frequency. Moreover, we show that the hyperpolarization-activated current (IH) has an opposing and complementary influence on the same firing features.


Asunto(s)
Neuronas Dopaminérgicas , Sustancia Negra , Potenciales de Acción , Animales , Ratones , Ratones Transgénicos , Porción Compacta de la Sustancia Negra
16.
STAR Protoc ; 2(1): 100387, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33778781

RESUMEN

Controversies remain over the standard procedures for the modeling of skin fibrosis and its use in in vitro testing of different drugs. Here, we report a reproducible protocol for producing a skin fibrosis model using human dermal fibroblasts seeded in collagen hydrogel. Detailed procedures for the fabrication of cell/hydrogel constructs, fibrosis induction, protein extraction for western blotting analysis are presented along with how this model can be employed for investigating the possible anti-fibrotic functions of certain chemical compounds.


Asunto(s)
Técnicas de Cultivo de Célula/métodos , Evaluación Preclínica de Medicamentos/métodos , Piel/efectos de los fármacos , Antifibróticos/análisis , Antifibróticos/farmacología , Proliferación Celular/efectos de los fármacos , Colágeno/metabolismo , Fibroblastos/efectos de los fármacos , Fibrosis/tratamiento farmacológico , Fibrosis/metabolismo , Humanos , Hidrogeles , Modelos Biológicos , Factor de Crecimiento Transformador beta1/metabolismo
17.
SLAS Discov ; 26(1): 77-87, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32808584

RESUMEN

MRG15 is a transcription factor containing the methyl-lysine reader chromodomain. Despite its involvement in different physiological and pathological states, to date the role of this protein has not been fully elucidated due to the lack of a specific and potent chemical probe.In this work, we report the development of a microscale thermophoresis (MST)-based assay for the study of MRG15-ligand binding interactions. After the development, the assay was validated using a small focused library and UNC1215 as the reference compound, to yield the identification of 10 MRG15 ligands with affinities ranging from 37.8 nM to 59.1 µM.Hence, our method is robust, convenient, and fast and could be applied to other methylation reader domain-containing proteins for the identification of new chemical probes.


Asunto(s)
Desarrollo de Medicamentos/métodos , Evaluación Preclínica de Medicamentos/métodos , Factores de Transcripción/química , Ligandos , Unión Proteica , Factores de Transcripción/antagonistas & inhibidores
18.
Cells ; 9(12)2020 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-33255167

RESUMEN

Natural cosmetic products have recently re-emerged as a novel tool able to counteract skin aging and skin related damages. In addition, recently achieved progress in nanomedicine opens a novel approach yielding from combination of modern nanotechnology with traditional treatment for innovative pharmacotherapeutics. In the present study, we investigated the antiaging effect of a pretreatment with Myrtus communis natural extract combined with a polycaprolactone nanofibrous scaffold (NanoPCL-M) on skin cell populations exposed to UV. We set up a novel model of skin on a bioreactor mimicking a crosstalk between keratinocytes, stem cells and fibroblasts, as in skin. Beta-galactosidase assay, indicating the amount of senescent cells, and viability assay, revealed that fibroblasts and stem cells pretreated with NanoPCL-M and then exposed to UV are superimposable to control cells, untreated and unexposed to UV damage. On the other hand, cells only exposed to UV stress, without NanoPCL-M pretreatment, exhibited a significantly higher yield of senescent elements. Keratinocyte-based 3D structures appeared disjointed after UV-stress, as compared to NanoPCL-M pretreated samples. Gene expression analysis performed on different senescence associated genes, revealed the activation of a molecular program of rejuvenation in stem cells pretreated with NanoPCL-M and then exposed to UV. Altogether, our results highlight a future translational application of NanoPCL-M to prevent skin aging.


Asunto(s)
Senescencia Celular/efectos de los fármacos , Nanofibras/química , Extractos Vegetales/farmacología , Piel/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Fibroblastos/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Humanos , Queratinocitos/efectos de los fármacos , Myrtus/química , Poliésteres/química , Envejecimiento de la Piel/efectos de los fármacos , Células Madre/efectos de los fármacos , Rayos Ultravioleta/efectos adversos
19.
J Radiol Case Rep ; 14(4): 21-37, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33082920

RESUMEN

Cervical spondylolisthesis indicates instability of the spine and can lead to pain, radiculopathy, myelopathy and vertebral artery stenosis. Currently degenerative cervical spondylolisthesis is a wait-and-watch condition with no treatment guidelines. A literature review and discussion will be provided. 8 females presented with neck pain, disability, and history of motor vehicle collision. Radiographs revealed abnormal cervical alignment, spinal canal narrowing, and spondylolistheses. After 30 sessions of Chiropractic BioPhysics® care over 12 weeks, patients reported improved symptoms and disabilities. Radiographs revealed improvements in cervical alignment, spondylolistheses, and spinal canal diameter. Motor vehicle collision may cause instability and abnormal alignment of the cervical spine leading to cervical spondylolisthesis. Improving spinal alignment may be an effective treatment to reduce vertebral subluxation and cervical spondylolistheses and improve neck disability as a result of improved spinal alignment.


Asunto(s)
Lordosis , Estenosis Espinal , Espondilolistesis , Biofisica , Vértebras Cervicales , Quiropráctica , Femenino , Humanos , Persona de Mediana Edad , Cuello , Dolor de Cuello , Radiculopatía , Radiografía , Canal Medular , Enfermedades de la Médula Espinal/complicaciones , Estenosis Espinal/diagnóstico por imagen , Espondilolistesis/complicaciones
20.
BMJ Open ; 10(8): e036684, 2020 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-32784257

RESUMEN

INTRODUCTION: The search for non-invasive procedures to reduce localised adiposity in aesthetics clinics has recently been increasing. In this context, procedures, such as cryolipolysis, ultracavitation, photobiomodulation (PBM) and other techniques have been proposed. Some studies have shown that PBM can be used in body contouring. However, there is no standardisation of the protocol. More than that, as in other techniques for reducing adipose tissue, the availability of triacylglycerol may affect the lipid profile in the blood, bringing consequences to the general health of an individual. This work will aim to compare the light wavelengths when using PBM as a technique for reducing the abdominal waist circumference, while also evaluating the efficacy of the method. Changes in the lipid profile in the blood, with a long-term follow-up, will also be appraised. METHODS AND ANALYSIS: This will be a controlled, randomised, double-blind, single-centred clinical trial. 174 patients will be recruited at the Nove de Julho University, Brazil, and then divided into three groups: Group A-RED PBM; Group B-INFRARED PBM; Group C-PLACEBO (Sham) treatment. The treatments will consist of eight sessions, two times a week, for 4 weeks. At each session, the participants will receive 30 minutes PBM (using a radiant exposure of 127 J/cm2), with an abdominal strap containing 4 LED clusters, with 72 devices each, following the indication of randomisation. All of the groups will receive 30 min of Aussie Current, at 4 kHz, modulated at 10 Hz, 40-60 mA. The main outcome of this study will be waist circumference reduction. The secondary variables will be anthropometric data, lipid profile, liver function and adipose tissue thickness, changes in the local microcirculation, and the quality of life and self-esteem. The analyses will be performed at four stages of the research, D0, end of the eighth session (D30), 15 days after the last session (FU15), 90 days after the last session (FU90) and 180 days after the last session (FU180). ETHICS AND DISSEMINATION: The Ethics Committee of the Nove de Julho University, Brazil, approved the modified version of this project under No. 3414146 on 26 June 2019. This study is not yet recruiting. The results obtained will be published in a peer-reviewed journal in the related field. TRIAL REGISTRATION NUMBER: Brazilian Registry of Clinical Trials-ReBec (RBR-9bwxcx).


Asunto(s)
Terapia por Luz de Baja Intensidad , Calidad de Vida , Brasil , Método Doble Ciego , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Circunferencia de la Cintura
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