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1.
Proc Natl Acad Sci U S A ; 120(20): e2218229120, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37155905

RESUMO

Castration-resistant prostate cancer (CRPC) poses a major clinical challenge with the androgen receptor (AR) remaining to be a critical oncogenic player. Several lines of evidence indicate that AR induces a distinct transcriptional program after androgen deprivation in CRPCs. However, the mechanism triggering AR binding to a distinct set of genomic loci in CRPC and how it promotes CRPC development remain unclear. We demonstrate here that atypical ubiquitination of AR mediated by an E3 ubiquitin ligase TRAF4 plays an important role in this process. TRAF4 is highly expressed in CRPCs and promotes CRPC development. It mediates K27-linked ubiquitination at the C-terminal tail of AR and increases its association with the pioneer factor FOXA1. Consequently, AR binds to a distinct set of genomic loci enriched with FOXA1- and HOXB13-binding motifs to drive different transcriptional programs including an olfactory transduction pathway. Through the surprising upregulation of olfactory receptor gene transcription, TRAF4 increases intracellular cAMP levels and boosts E2F transcription factor activity to promote cell proliferation under androgen deprivation conditions. Altogether, these findings reveal a posttranslational mechanism driving AR-regulated transcriptional reprogramming to provide survival advantages for prostate cancer cells under castration conditions.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Receptores Androgênicos , Masculino , Humanos , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Androgênios , Antagonistas de Androgênios , Fator 4 Associado a Receptor de TNF/metabolismo , Linhagem Celular Tumoral , Ubiquitinação , Regulação Neoplásica da Expressão Gênica
3.
Bioorg Med Chem ; 27(2): 436-441, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30581047

RESUMO

The 26S proteasome and calpain are linked to a number of important human diseases. Here, we report a series of analogues of the prototypical tripeptide aldehyde inhibitor MG132 that show a unique combination of high activity and selectivity for calpains over proteasome. Tripeptide aldehydes (1-3) with an aromatic P3 substituent show enhanced activity and selectivity against ovine calpain 2 relative to chymotrypsin-like activity of proteasome. Docking studies reveal the key contacts between inhibitors and calpain to confirm the importance of the S3 pocket with respect to selectivity between calpains 1 and 2 and the proteasome.


Assuntos
Inibidores de Cisteína Proteinase/farmacologia , Leupeptinas/farmacologia , Inibidores de Proteassoma/farmacologia , Animais , Antimaláricos/síntese química , Antimaláricos/química , Antimaláricos/farmacologia , Calpaína/química , Domínio Catalítico , Inibidores de Cisteína Proteinase/síntese química , Inibidores de Cisteína Proteinase/química , Leupeptinas/síntese química , Leupeptinas/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Plasmodium falciparum/enzimologia , Complexo de Endopeptidases do Proteassoma/química , Inibidores de Proteassoma/síntese química , Inibidores de Proteassoma/química , Conformação Proteica , Ratos , Ovinos , Suínos
4.
J Foot Ankle Surg ; 58(6): 1267-1272, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31350139

RESUMO

The area of skin supplied by the cutaneous branch of the obturator nerve (CBO) is highly variable. Although most introductory anatomy texts describe the CBO as innervating only a portion of the medial thigh, there are numerous reports in the literature of CBOs passing the knee to innervate the proximal, middle, or even distal leg. There are no previous reports of CBOs extending to the ankle and foot. Herein we describe 2 cases of CBOs extending at least to the medial foot. Both cases were discovered incidentally, during routine cadaver dissections by osteopathic and podiatric medical students in the anatomy laboratory of Western University of Health Sciences in California. In both instances, the anomalously long CBOs shared several characteristics: (1) they arose as direct branches of the anterior division of the obturator nerve, not from the subsartorial plexus; (2) they coursed immediately posterior to the great saphenous vein from the distal thigh to the distal leg, only deviating away from the saphenous vein just above the medial malleolus; and (3) they terminated in radiating fibers to the posterior half of the medial ankle and foot. In both cases, the saphenous branch of the femoral nerve was present but restricted to the area anterior to the great saphenous vein. It is likely that the variant CBOs carried fibers of the L4 spinal nerve and thus provided cutaneous innervation to the medial foot and ankle, a function most commonly reserved for the saphenous branch of the femoral nerve distal to the knee. Saphenous neuropathy is a common postoperative complication of saphenous cutdowns for coronary artery bypass grafts, so the potential involvement of a long CBO can add additional complexity to regional anesthetic blocks for foot and ankle surgery and procedures such as vein harvesting for coronary artery bypass grafts.


Assuntos
Tornozelo/anatomia & histologia , Pé/anatomia & histologia , Nervo Obturador/anatomia & histologia , Idoso , Cadáver , Humanos , Masculino
5.
Proc Natl Acad Sci U S A ; 111(3): 990-5, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24395775

RESUMO

Synthetic matrices emulating the physicochemical properties of tissue-specific ECMs are being developed at a rapid pace to regulate stem cell fate. Biomaterials containing calcium phosphate (CaP) moieties have been shown to support osteogenic differentiation of stem and progenitor cells and bone tissue formation. By using a mineralized synthetic matrix mimicking a CaP-rich bone microenvironment, we examine a molecular mechanism through which CaP minerals induce osteogenesis of human mesenchymal stem cells with an emphasis on phosphate metabolism. Our studies show that extracellular phosphate uptake through solute carrier family 20 (phosphate transporter), member 1 (SLC20a1) supports osteogenic differentiation of human mesenchymal stem cells via adenosine, an ATP metabolite, which acts as an autocrine/paracrine signaling molecule through A2b adenosine receptor. Perturbation of SLC20a1 abrogates osteogenic differentiation by decreasing intramitochondrial phosphate and ATP synthesis. Collectively, this study offers the demonstration of a previously unknown mechanism for the beneficial role of CaP biomaterials in bone repair and the role of phosphate ions in bone physiology and regeneration. These findings also begin to shed light on the role of ATP metabolism in bone homeostasis, which may be exploited to treat bone metabolic diseases.


Assuntos
Adenosina/metabolismo , Fosfatos de Cálcio/química , Regulação da Expressão Gênica , Células-Tronco/citologia , Trifosfato de Adenosina/metabolismo , Materiais Biocompatíveis/química , Osso e Ossos/metabolismo , Fosfatos de Cálcio/metabolismo , Diferenciação Celular , Células Cultivadas/citologia , Cromatografia Líquida de Alta Pressão , Homeostase , Humanos , Células-Tronco Mesenquimais/citologia , Osteogênese/fisiologia , Fenótipo , Fosfatos/metabolismo , RNA Interferente Pequeno/metabolismo , Receptor A2B de Adenosina/metabolismo , Regeneração , Transdução de Sinais , Proteínas Cotransportadoras de Sódio-Fosfato Tipo III/metabolismo
6.
Proc Natl Acad Sci U S A ; 111(33): 12163-8, 2014 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-25092323

RESUMO

The RAR-related orphan receptor gamma t (RORγt) is a nuclear receptor required for generating IL-17-producing CD4(+) Th17 T cells, which are essential in host defense and may play key pathogenic roles in autoimmune diseases. Oxysterols elicit profound effects on immune and inflammatory responses as well as on cholesterol and lipid metabolism. Here, we describe the identification of several naturally occurring oxysterols as RORγt agonists. The most potent and selective activator for RORγt is 7ß, 27-dihydroxycholesterol (7ß, 27-OHC). We show that these oxysterols reverse the inhibitory effect of an RORγt antagonist, ursolic acid, in RORγ- or RORγt-dependent cell-based reporter assays. These ligands bind directly to recombinant RORγ ligand binding domain (LBD), promote recruitment of a coactivator peptide, and reduce binding of a corepressor peptide to RORγ LBD. In primary cells, 7ß, 27-OHC and 7α, 27-OHC enhance the differentiation of murine and human IL-17-producing Th17 cells in an RORγt-dependent manner. Importantly, we showed that Th17, but not Th1 cells, preferentially produce these two oxysterols. In vivo, administration of 7ß, 27-OHC in mice enhanced IL-17 production. Mice deficient in CYP27A1, a key enzyme in generating these oxysterols, showed significant reduction of IL-17-producing cells, including CD4(+) and γδ(+) T cells, similar to the deficiency observed in RORγt knockout mice. Our results reveal a previously unknown mechanism for selected oxysterols as immune modulators and a direct role for CYP27A1 in generating these RORγt agonist ligands, which we propose as RORγt endogenous ligands, driving both innate and adaptive IL-17-dependent immune responses.


Assuntos
Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/agonistas , Esteróis/farmacologia , Células Th17/citologia , Animais , Diferenciação Celular , Colestanotriol 26-Mono-Oxigenase/metabolismo , Interleucina-17/biossíntese , Ligantes , Camundongos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Esteróis/metabolismo
7.
Am J Physiol Heart Circ Physiol ; 310(3): H426-35, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26637557

RESUMO

Pathological enhancement of late Na(+) current (INa) can potentially modify intracellular ion homeostasis and contribute to cardiac dysfunction. We tested the hypothesis that modulation of late INa can be a source of intracellular Na(+) ([Na(+)]i) overload. Late INa was enhanced by exposing rabbit ventricular myocytes to Anemonia sulcata toxin II (ATX-II) and measured using whole cell patch-clamp technique. [Na(+)]i was determined with fluorescent dye Asante NaTRIUM Green-2 AM. Pacing-induced changes in the dye fluorescence measured at 37°C were more pronounced in ATX-II-treated cells than in control (dye washout prevented calibration). At 22-24°C, resting [Na(+)]i was 6.6 ± 0.8 mM. Treatment with 5 nM ATX-II increased late INa 8.7-fold. [Na(+)]i measured after 2 min of electrical stimulation (1 Hz) was 10.8 ± 1.5 mM and 22.1 ± 1.6 mM (P < 0.001) in the absence and presence of 5 nM ATX-II, respectively. Inhibition of late INa with GS-967 (1 µM) prevented Na(+) i accumulation. A strong positive correlation was observed between the late INa and the pacing-induced increase of [Na(+)]i (R(2) = 0.88) and between the rise in [Na(+)]i and the increases in cytosolic Ca(2+) (R(2) = 0.96). ATX-II, tetrodotoxin, or GS-967 did not affect [Na(+)]i in quiescent myocytes suggesting that late INa was solely responsible for triggering the ATX-II effect on [Na(+)]i. Experiments with pinacidil and E4031 indicate that prolongation of the action potential contributes to as much as 50% of the [Na(+)]i overload associated with the increase in late INa caused by ATX-II. Enhancement of late INa can cause intracellular Na(+) overload in ventricular myocytes.


Assuntos
Cálcio/metabolismo , Cardiotônicos/farmacologia , Venenos de Cnidários/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Canais de Sódio/efeitos dos fármacos , Sódio/metabolismo , Animais , Proteínas de Fluorescência Verde , Ventrículos do Coração/citologia , Indóis , Miócitos Cardíacos/metabolismo , Imagem Óptica , Técnicas de Patch-Clamp , Coelhos , Canais de Sódio/metabolismo
8.
Ann Rheum Dis ; 73(3): 600-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24126456

RESUMO

OBJECTIVE: The histamine H4 receptor (H4R) has been shown to drive inflammatory responses in models of asthma, colitis and dermatitis, and in these models it appears to affect both innate and adaptive immune responses. In this study, we used both H4R-deficient mice and a specific H4R antagonist, JNJ 28307474, to investigate the involvement of the H4R in mouse arthritis models. METHODS: H4R-deficient mice and wild-type mice administered the H4R antagonist were studied in models of collagen antibody-induced arthritis (CAIA) and collagen-induced arthritis (CIA). The impact on Th17 cells was assessed by restimulation of inguinal lymphocytes in the disease or immunisation models and with in vitro stimulation of whole blood. RESULTS: Both H4R-deficient mice and mice treated with the H4R antagonist exhibited reduced arthritis disease severity in both CAIA and CIA models. This was evident from the reduction in disease score and in joint histology. In the CIA model, treatment with the H4R antagonist reduced the number of interleukin (IL)-17 positive cells in the lymph node and the total production of IL-17. Th17 cell development in vivo was reduced in H4R-deficient mice or in mice treated with an H4R antagonist. Finally, treatment of both mouse and human blood with an H4R antagonist reduced the production of IL-17 when cells were stimulated in vitro. CONCLUSIONS: These results implicate the H4R in disease progression in arthritis and in the production of IL-17 from Th17 cells. This work supports future clinical exploration of H4R antagonists for the treatment of rheumatoid arthritis.


Assuntos
Artrite Experimental/imunologia , Receptores Acoplados a Proteínas G/imunologia , Receptores Histamínicos/imunologia , Células Th17/imunologia , Animais , Artrite Experimental/patologia , Artrite Experimental/prevenção & controle , Células Cultivadas , Relação Dose-Resposta a Droga , Interleucina-17/biossíntese , Lipopolissacarídeos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/deficiência , Receptores Histamínicos/deficiência , Receptores Histamínicos H4 , Índice de Gravidade de Doença
9.
Innovations (Phila) ; 19(2): 143-149, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38504149

RESUMO

OBJECTIVE: This study evaluated the efficacy of the Minimally Invasive Targeted Resection (MiTR) device, a novel electrosurgical instrument that allows for targeted excision of a lung abnormality while using bipolar radiofrequency (RF) energy to seal blood vessels and airways. METHODS: The MiTR system was evaluated in 7 acute and 2 chronic porcine (7-day) models to evaluate the efficacy of tissue excision with bipolar RF sealing of blood vessels and airways and application of an autologous blood patch into the excised tissue cavity. Air leak was recorded for all evaluations. The study was approved by the institutional ethical board. RESULTS: Nineteen lung tissue samples, measuring 2.5 cm long × 1.2 cm diameter, were excised. In 8 of 9 animals (89%), hemostasis and pneumostasis were observed visually at the completion of the procedure. In 2 of 2 chronic animals (100%), hemostasis and pneumostasis persisted for the 7-day observation period. Histologic examination of the excised samples showed preservation of the core parenchymal architecture without evident tissue damage of the samples that would impair pathologic analysis. CONCLUSIONS: Percutaneous resection of targeted lung tissue with the MiTR system demonstrated hemostasis and pneumostasis while obtaining a histologically intact sample. After regulatory approval, the use of this device could offer more tissue for analysis than a transthoracic needle biopsy or bronchoscopy and a far less invasive alternative to video-assisted thoracic surgery or thoracotomy. This may also expand patient and physician options for the early diagnosis and treatment of lung cancer.


Assuntos
Pulmão , Animais , Suínos , Pulmão/cirurgia , Pulmão/patologia , Pneumonectomia/instrumentação , Pneumonectomia/métodos , Eletrocirurgia/instrumentação , Eletrocirurgia/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Hemostasia Cirúrgica/instrumentação , Hemostasia Cirúrgica/métodos , Cirurgia Assistida por Computador/métodos , Cirurgia Assistida por Computador/instrumentação
10.
Chemistry ; 19(24): 7975-81, 2013 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-23606616

RESUMO

Peptide-derived protease inhibitors are an important class of compounds with the potential to treat a wide range of diseases. Herein, we describe the synthesis of a series of triazole-containing macrocyclic protease inhibitors pre-organized into a ß-strand conformation and an evaluation of their activity against a panel of proteases. Acyclic azido-alkyne-based aldehydes are also evaluated for comparison. The macrocyclic peptidomimetics showed considerable activity towards calpain II, cathepsin L and S, and the 20S proteasome chymotrypsin-like activity. Some of the first examples of highly potent macrocyclic inhibitors of cathepsin S were identified. These adopt a well-defined ß-strand geometry as shown by NMR spectroscopy, X-ray analysis, and molecular docking studies.


Assuntos
Compostos Macrocíclicos/síntese química , Peptídeos/química , Inibidores de Proteases/síntese química , Triazóis/síntese química , Calpaína/antagonistas & inibidores , Catepsina L/antagonistas & inibidores , Química Click , Compostos Macrocíclicos/química , Compostos Macrocíclicos/farmacologia , Conformação Molecular , Ressonância Magnética Nuclear Biomolecular , Peptidomiméticos , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Triazóis/química , Triazóis/farmacologia
11.
Ann Allergy Asthma Immunol ; 111(6): 562-6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24267369

RESUMO

BACKGROUND: Rush immunotherapy (RIT) schedules can expedite protection in individuals sensitive to imported fire ant (IFA) stings. OBJECTIVE: To evaluate the safety and efficacy of 1-day RIT with IFA whole body extract (WBE) and determine the benefit of premedication with antihistamines and prednisone. METHODS: Patients with systemic reactions to IFAs and evidence of specific IgE by skin test or serologic test started a 1-day RIT protocol without premedication. The 1-day RIT protocol consisted of a total of 10 injections every 30 to 60 minutes to achieve a 0.3-mL 1:100 (wt/vol) dose. A higher systemic reaction rate (SRR) prompted protocol revision to include a 3-day course of oral 20 mg of prednisone twice daily, 150 mg of ranitidine, and 10 mg of loratadine started 2 days before the 1-day RIT. Patients returned on days 8 and 15 to receive a 0.5 mL 1:100 (wt/vol) maintenance injection. The effectiveness of the RIT was evaluated with a sting challenge on approximately day 22. RESULTS: Eighty of the 96 patients enrolled initiated the 1-day RIT. The first nonpremedicated group exhibited a SRR of 24.3% (9 of 37 patients), whereas the revised premedicated group had a SRR of 9.5% (4 of 42 patients; P = .07). The most severe reaction during RIT included dizziness, angioedema, and urticaria. Sting challenges on 53 patients resulted in 1 mild rhinitis reaction (efficacy, 98.1%). CONCLUSION: One-day RIT with IFA WBE for IFA hypersensitivity is efficacious. Although there was a trend with premedications to reduce SRRs during the RIT, safety data with premedication require confirmation in a larger trial.


Assuntos
Alérgenos/administração & dosagem , Formigas/imunologia , Misturas Complexas/administração & dosagem , Dessensibilização Imunológica/métodos , Hipersensibilidade Imediata/terapia , Adolescente , Adulto , Animais , Mordeduras e Picadas/imunologia , Feminino , Antagonistas dos Receptores Histamínicos/administração & dosagem , Humanos , Loratadina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Ranitidina/administração & dosagem , Testes Cutâneos , Adulto Jovem
12.
Bioorg Med Chem Lett ; 23(4): 1070-4, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23313244

RESUMO

Novel classes of tetrahydropyrido-pyrazole thioether amines and arylalkynes that display potency against human Cathepsin S have been previously reported. Here, key pharmacophoric elements of these two classes are merged, and SAR investigations of the P4 region are described, in conjunction with re-optimization of the P5 and P1/P1'/P3 regions. Identification of meta-substituted arylalkynes with good potency and improved solubility is described.


Assuntos
Alcinos/química , Alcinos/farmacologia , Catepsinas/antagonistas & inibidores , Catepsinas/química , Pirazóis/química , Pirazóis/farmacologia , Humanos , Relação Estrutura-Atividade
13.
Mol Cell Proteomics ; 10(10): M111.010538, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21685506

RESUMO

The flagellum of African trypanosomes is an essential and multifunctional organelle that functions in motility, cell morphogenesis, and host-parasite interaction. Previous studies of the trypanosome flagellum have been limited by the inability to purify flagella without first removing the flagellar membrane. This limitation is particularly relevant in the context of studying flagellum signaling, as signaling requires surface-exposed proteins in the flagellar membrane and soluble signaling proteins in the flagellar matrix. Here we employ a combination of genetic and mechanical approaches to purify intact flagella from the African trypanosome, Trypanosoma brucei, in its mammalian-infectious stage. We combined flagellum purification with affinity-purification of surface-exposed proteins to conduct independent proteomic analyses of the flagellum surface and matrix fractions. The proteins identified encompass a broad range of molecular functionalities, including many predicted to function in signaling. Immunofluorescence and RNA interference studies demonstrate flagellum localization and function for proteins identified and provide insight into mechanisms of flagellum attachment and motility. The flagellum surface proteome includes many T. brucei-specific proteins and is enriched for proteins up-regulated in the mammalian-infectious stage of the parasite life-cycle. The combined results indicate that the flagellum surface presents a diverse and dynamic host-parasite interface that is well-suited for host-parasite signaling.


Assuntos
Flagelos/metabolismo , Proteínas de Membrana/análise , Proteínas de Membrana/metabolismo , Proteoma/análise , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/metabolismo , Animais , Movimento Celular , Proteínas da Matriz Extracelular/análise , Interações Hospedeiro-Parasita , Humanos , Estágios do Ciclo de Vida , Proteoma/genética , Proteoma/metabolismo , Proteínas de Protozoários/análise , Interferência de RNA , Transdução de Sinais
14.
Antioxidants (Basel) ; 12(8)2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37627531

RESUMO

Oxidative stress is proven to be a leading factor in a multitude of adverse conditions, from Alzheimer's disease to cancer. Thus, developing effective radical scavenging agents to eliminate reactive oxygen species (ROS) driving many oxidative processes has become critical. In addition to conventional antioxidants, nanoscale structures and metal-organic complexes have recently shown promising potential for radical scavenging. To design an optimal nanoscale ROS scavenging agent, we have synthesized ten types of biocompatible graphene quantum dots (GQDs) augmented with various metal dopants. The radical scavenging abilities of these novel metal-doped GQD structures were, for the first time, assessed via the DPPH, KMnO4, and RHB (Rhodamine B protectant) assays. While all metal-doped GQDs consistently demonstrate antioxidant properties higher than the undoped cores, aluminum-doped GQDs exhibit 60-95% radical scavenging ability of ascorbic acid positive control. Tm-doped GQDs match the radical scavenging properties of ascorbic acid in the KMnO4 assay. All doped GQD structures possess fluorescence imaging capabilities that enable their tracking in vitro, ensuring their successful cellular internalization. Given such multifunctionality, biocompatible doped GQD antioxidants can become prospective candidates for multimodal therapeutics, including the reduction of ROS with concomitant imaging and therapeutic delivery to cancer tumors.

15.
Nanomaterials (Basel) ; 13(5)2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36903683

RESUMO

Graphene-based materials have been the subject of interest for photothermal therapy due to their high light-to-heat conversion efficiency. Based on recent studies, graphene quantum dots (GQDs) are expected to possess advantageous photothermal properties and facilitate fluorescence image-tracking in the visible and near-infrared (NIR), while surpassing other graphene-based materials in their biocompatibility. Several GQD structures including reduced graphene quantum dots (RGQDs) derived from reduced graphene oxide via top-down oxidation and hyaluronic acid graphene quantum dots (HGQDs) hydrothermally bottom-up synthesized from molecular hyaluronic acid were employed to test these capabilities in the present work. These GQDs possess substantial NIR absorption and fluorescence throughout the visible and NIR beneficial for in vivo imaging while being biocompatible at up to 1.7 mg/mL concentrations. In aqueous suspensions, RGQDs and HGQDs irradiated with a low power (0.9 W/cm2) 808 nm NIR laser facilitate a temperature increase up to 47.0 °C, which is sufficient for cancer tumor ablation. In vitro photothermal experiments sampling multiple conditions directly in the 96-well plate were performed using an automated simultaneous irradiation/measurement system developed on the basis of a 3D printer. In this study, HGQDs and RGQDs facilitated the heating of HeLa cancer cells up to 54.5 °C, leading to the drastic inhibition of cell viability from over 80% down to 22.9%. GQD's fluorescence in the visible and NIR traces their successful internalization into HeLa cells maximized at 20 h suggesting both extracellular and intracellular photothermal treatment capabilities. The combination of the photothermal and imaging modalities tested in vitro makes the GQDs developed in this work prospective agents for cancer theragnostics.

16.
Sci Adv ; 9(36): eadi2232, 2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37682999

RESUMO

Vitamin B6 is a vital micronutrient across cell types and tissues, and dysregulated B6 levels contribute to human disease. Despite its importance, how B6 vitamer levels are regulated is not well understood. Here, we provide evidence that B6 dynamics are rapidly tuned by precise compartmentation of pyridoxal kinase (PDXK), the rate-limiting B6 enzyme. We show that canonical Wnt rapidly led to the accumulation of inactive B6 by shunting cytosolic PDXK into lysosomes. PDXK was modified with methyl-arginine Degron (MrDegron), a protein tag for lysosomes, which enabled delivery via microautophagy. Hyperactive lysosomes resulted in the continuous degradation of PDXK and B6 deficiency that promoted proliferation in Wnt-driven colorectal cancer (CRC) cells. Pharmacological or genetic disruption of the coordinated MrDegron proteolytic pathway was sufficient to reduce CRC survival in cells and organoid models. In sum, this work contributes to the repertoire of micronutrient-regulated processes that enable cancer cell growth and provides insight into the functional impact of B6 deficiencies for survival.


Assuntos
Peptídeo Hidrolases , Vitamina B 6 , Humanos , Proteólise , Micronutrientes , Vitaminas
17.
Cureus ; 14(5): e25028, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35719804

RESUMO

We present a unique case of a 60-year-old male with congestive heart failure who was admitted for a pre-syncopal episode and found to be in atrial fibrillation with rapid ventricular response (RVR). In order to effectively rate control the patient, he was administered an amiodarone bolus and intravenous (IV) infusion over 24 hours, along with a single oral 200 mg dose the following day. The patient subsequently developed acute hepatotoxicity along with features of acute kidney injury (AKI), pulmonary distress, and leukocytosis. After ruling out other etiologies for acute liver, pulmonary, and kidney injury, amiodarone-induced multi-organ toxicity was suspected and amiodarone was discontinued. Within hours of amiodarone discontinuation, the patient's clinical status and organ function improved remarkably. In the setting of a patient being treated with IV amiodarone and presenting with sudden signs of dyspnea, acute elevation of transaminases and AKI within one to two days of initial dosing, acute amiodarone-induced organ toxicity should be considered.

18.
J Osteopath Med ; 122(2): 95-103, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34995434

RESUMO

CONTEXT: Age-dependent dementia is a devastating disorder afflicting a growing older population. Although pharmacological agents improve symptoms of dementia, age-related comorbidities combined with adverse effects often outweigh their clinical benefits. Therefore, nonpharmacological therapies are being investigated as an alternative. In a previous pilot study, aged rats demonstrated improved spatial memory after osteopathic cranial manipulative medicine (OCMM) treatment. OBJECTIVES: In this continuation of the pilot study, we examine the effect of OCMM on gene expression to elicit possible explanations for the improvement in spatial memory. METHODS: OCMM was performed on six of 12 elderly rats every day for 7 days. Rats were then euthanized to obtain the brain tissue, from which RNA samples were extracted. RNA from three treated and three controls were of sufficient quality for sequencing. These samples were sequenced utilizing next-generation sequencing from Illumina NextSeq. The Cufflinks software suite was utilized to assemble transcriptomes and quantify the RNA expression level for each sample. RESULTS: Transcriptome analysis revealed that OCMM significantly affected the expression of 36 genes in the neuronal pathway (false discovery rate [FDR] <0.004). The top five neuronal genes with the largest-fold change were part of the cholinergic neurotransmission mechanism, which is known to affect cognitive function. In addition, 39.9% of 426 significant differentially expressed (SDE) genes (FDR<0.004) have been previously implicated in neurological disorders. Overall, changes in SDE genes combined with their role in central nervous system signaling pathways suggest a connection to previously reported OCMM-induced behavioral and biochemical changes in aged rats. CONCLUSIONS: Results from this pilot study provide sufficient evidence to support a more extensive study with a larger sample size. Further investigation in this direction will provide a better understanding of the molecular mechanisms of OCMM and its potential in clinical applications. With clinical validation, OCMM could represent a much-needed low-risk adjunct treatment for age-related dementia including Alzheimer's disease.


Assuntos
Osteopatia , Animais , Colinérgicos , Expressão Gênica , Humanos , Osteopatia/métodos , Projetos Piloto , Ratos
19.
Metabolites ; 12(10)2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36295863

RESUMO

Vitamin B micronutrients are essential regulators of one carbon metabolism that ensures human health. Vitamin B9, or folate, lies at the heart of the folate cycle and converges with the methionine cycle to complete the one carbon pathway. Additionally, vitamin B6 contributes by orchestrating the flux of one carbon cycling. Dysregulation of vitamin B contributes to altered biochemical signaling that manifests in a spectrum of human diseases. This review presents an analysis of the past, present, and future work, highlighting the interplay between folate and vitamin B6 in one carbon metabolism. Emerging insights include advances in metabolomic-based mass spectrometry and the use of live-cell metabolic labeling. Cancer is used as a focal point to dissect vitamin crosstalk and highlight new insights into the roles of folate and vitamin B6 in metabolic control. This collection of vitamin-based research detailing the trends of one carbon metabolism in human disease exemplifies how the future of personalized medicine could unfold using this new base of knowledge and ultimately provide next-generation therapeutics.

20.
ACS Biomater Sci Eng ; 8(11): 4965-4975, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36179254

RESUMO

Sonography offers many advantages over standard methods of diagnostic imaging due to its non-invasiveness, substantial tissue penetration depth, and low cost. The benefits of ultrasound imaging call for the development of ultrasound-trackable drug delivery vehicles that can address a variety of therapeutic targets. One disadvantage of the technique is the lack of high-precision imaging, which can be circumvented by complementing ultrasound contrast agents with visible and, especially, near-infrared (NIR) fluorophores. In this work, we, for the first time, develop a variety of lightly metal-doped (iron oxide, silver, thulium, neodymium, cerium oxide, cerium chloride, and molybdenum disulfide) nitrogen-containing graphene quantum dots (NGQDs) that demonstrate high-contrast properties in the ultrasound brightness mode and exhibit visible and/or near-infrared fluorescence imaging capabilities. NGQDs synthesized from glucosamine precursors with only a few percent metal doping do not introduce additional toxicity in vitro, yielding over 80% cell viability up to 2 mg/mL doses. Their small (<50 nm) sizes warrant effective cell internalization, while oxygen-containing surface functional groups decorating their surfaces render NGQDs water soluble and allow for the attachment of therapeutics and targeting agents. Utilizing visible and/or NIR fluorescence, we demonstrate that metal-doped NGQDs experience maximum accumulation within the HEK-293 cells 6-12 h after treatment. The successful 10-fold ultrasound signal enhancement is observed at 0.5-1.6 mg/mL for most metal-doped NGQDs in the vascular phantom, agarose gel, and animal tissue. A combination of non-invasive ultrasound imaging with capabilities of high-precision fluorescence tracking makes these metal-doped NGQDs a viable agent for a variety of theragnostic applications.


Assuntos
Grafite , Pontos Quânticos , Animais , Humanos , Células HEK293 , Nitrogênio , Imagem Óptica , Ultrassonografia
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