Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
1.
bioRxiv ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38586011

RESUMO

Microglia-driven neuroinflammation plays an important role in the development of Alzheimer's disease (AD). Microglia activation is accompanied by the formation and chronic maintenance of TLR4 inflammarafts, defined as enlarged and cholesterol-rich lipid rafts serving as an assembly platform for TLR4 dimers and complexes of other inflammatory receptors. The secreted apoA-I binding protein (APOA1BP or AIBP) binds TLR4 and selectively targets cholesterol depletion machinery to TLR4 inflammaraft expressing inflammatory, but not homeostatic microglia. Here we demonstrated that amyloid-beta (Aß) induced formation of TLR4 inflammarafts in microglia in vitro and in the brain of APP/PS1 mice. Mitochondria in Apoa1bp-/- APP/PS1 microglia were hyperbranched and cupped, which was accompanied by increased ROS and the dilated ER. The size and number of Aß plaques and neuronal cell death were significantly increased, and the animal survival was decreased in Apoa1bp-/- APP/PS1 compared to APP/PS1 female mice. These results suggest that AIBP exerts control of TLR4 inflammarafts and mitochondrial dynamics in microglia and plays a protective role in AD associated oxidative stress and neurodegeneration.

2.
Cells ; 13(2)2024 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-38275823

RESUMO

Glaucoma is a group of ocular diseases that cause irreversible blindness. It is characterized by multifactorial degeneration of the optic nerve axons and retinal ganglion cells (RGCs), resulting in the loss of vision. Major components of glaucoma pathogenesis include glia-driven neuroinflammation and impairment of mitochondrial dynamics and bioenergetics, leading to retinal neurodegeneration. In this review article, we summarize current evidence for the emerging role of apolipoprotein A-I binding protein (AIBP) as an important anti-inflammatory and neuroprotective factor in the retina. Due to its association with toll-like receptor 4 (TLR4), extracellular AIBP selectively removes excess cholesterol from the plasma membrane of inflammatory and activated cells. This results in the reduced expression of TLR4-associated, cholesterol-rich lipid rafts and the inhibition of downstream inflammatory signaling. Intracellular AIBP is localized to mitochondria and modulates mitophagy through the ubiquitination of mitofusins 1 and 2. Importantly, elevated intraocular pressure induces AIBP deficiency in mouse models and in human glaucomatous retina. AIBP deficiency leads to the activation of TLR4 in Müller glia, triggering mitochondrial dysfunction in both RGCs and Müller glia, and compromising visual function in a mouse model. Conversely, restoring AIBP expression in the retina reduces neuroinflammation, prevents RGCs death, and protects visual function. These results provide new insight into the mechanism of AIBP function in the retina and suggest a therapeutic potential for restoring retinal AIBP expression in the treatment of glaucoma.


Assuntos
Glaucoma , Receptor 4 Toll-Like , Camundongos , Animais , Humanos , Receptor 4 Toll-Like/metabolismo , Doenças Neuroinflamatórias , Glaucoma/metabolismo , Retina/metabolismo , Colesterol/metabolismo
3.
bioRxiv ; 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-37905114

RESUMO

Glaucoma is a neurodegenerative disease manifested in retinal ganglion cell (RGC) death and irreversible blindness. While lowering intraocular pressure (IOP) is the only proven therapeutic strategy in glaucoma, it is insufficient for preventing disease progression, thus justifying the recent focus on targeting retinal neuroinflammation and preserving RGCs. We have identified apolipoprotein A-I binding protein (AIBP) as the protein regulating several mechanisms of retinal neurodegeneration. AIBP controls excessive cholesterol accumulation via upregulating the cholesterol transporter ATP-binding cassette transporter 1 (ABCA1) and reduces inflammatory signaling via toll-like receptor 4 (TLR4) and mitochondrial dysfunction. ABCA1, TLR4 and oxidative phosphorylation components are genetically linked to primary open-angle glaucoma. Here we demonstrated that AIBP and ABCA1 expression was decreased, while TLR4, interleukin 1 beta (IL-1 beta), and the cholesterol content increased in the retina of patients with glaucoma and in mouse models of glaucoma. Restoring AIBP expression by a single intravitreal injection of adeno-associated virus (AAV)-AIBP protected RGCs in glaucomatous DBA/2J mice, in mice with microbead-induced chronic IOP elevation, and optic nerve crush. In addition, AIBP expression attenuated TLR4 and IL-1 beta expression, localization of TLR4 to lipid rafts, reduced cholesterol accumulation, and ameliorated visual dysfunction. These studies collectively indicate that restoring AIBP expression in the glaucomatous retina reduces neuroinflammation and protects RGCs and Muller glia, suggesting the therapeutic potential of AAV-AIBP in human glaucoma.

4.
Curr Opin Lipidol ; 34(5): 189-195, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37527160

RESUMO

PURPOSE OF REVIEW: Advances in single cell techniques revealed a remarkable diversity in macrophage gene expression profiles in atherosclerosis. However, the diversity of functional processes at the macrophage plasma membrane remains less studied. This review summarizes recent advances in characterization of lipid rafts, where inflammatory receptors assemble, in macrophages that undergo reprogramming in atherosclerotic lesions and in vitro under conditions relevant to the development of atherosclerosis. RECENT FINDINGS: The term inflammarafts refers to enlarged lipid rafts with increased cholesterol content, hosting components of inflammatory receptor complexes assembled in close proximity, including TLR4-TLR4, TLR2-TLR1 and TLR2-CD36 dimers. Macrophages decorated with inflammarafts maintain chronic inflammatory gene expression and are primed to an augmented response to additional inflammatory stimuli. In mouse atherosclerotic lesions, inflammarafts are expressed primarily in nonfoamy macrophages and less in lipid-laden foam cells. This agrees with the reported suppression of inflammatory programs in foam cells. In contrast, nonfoamy macrophages expressing inflammarafts are the major inflammatory population in atherosclerotic lesions. Discussed are emerging reports that help understand formation and persistence of inflammarafts and the potential of inflammarafts as a novel therapeutic target. SUMMARY: Chronic maintenance of inflammarafts in nonfoamy macrophages serves as an effector mechanism of inflammatory macrophage reprogramming in atherosclerosis.


Assuntos
Aterosclerose , Placa Aterosclerótica , Animais , Camundongos , Receptor 4 Toll-Like/metabolismo , Receptor 2 Toll-Like/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Aterosclerose/metabolismo , Células Espumosas/metabolismo , Placa Aterosclerótica/patologia
5.
Skin Res Technol ; 29(5): e13326, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37231925

RESUMO

BACKGROUND: When Wnt binds to the N-terminal of Frizzled, a conformational change occurs in the C-terminal of Frizzled, which binds to Dishevelled1 (Dvl1), a Wnt signaling component protein. When Dvl1 binds to the C-terminal of Frizzled, the concentration of ß-catenin increases and it enters the nucleus to transmit cell proliferation signals. CXXC-type zinc finger protein 5 (CXXC5) binds to the Frizzled binding site of Dvl1 and interferes with Dvl1-Frizzled binding. Therefore, blocking CXXC5-Dvl1 binding may induce Wnt signal transduction. MATERIALS AND METHODS: We used WD-aptamer, a DNA aptamer that specifically binds to Dvl1 and interferes with CXXC5-Dvl1 interaction. We confirmed the penetration of WD-aptamer into human hair follicle dermal papilla cells (HFDPCs) and measured ß-catenin expression following treatment with WD-aptamer in HFDPCs, wherein Wnt signaling was activated by Wnt3a. In addition, MTT assay was performed to investigate the effect of WD-aptamer on cell proliferation. RESULTS: WD-aptamer penetrated the cell, affected Wnt signaling, and increased ß-catenin expression, which plays an important role in signaling. Additionally, WD-aptamer induced HFDPC proliferation. CONCLUSION: CXXC5-associated negative feedback of Wnt/ß-catenin signaling can be regulated by interfering with CXXC5-Dvl1 interaction.


Assuntos
Aptâmeros de Nucleotídeos , Via de Sinalização Wnt , Humanos , Via de Sinalização Wnt/fisiologia , Folículo Piloso/metabolismo , beta Catenina/metabolismo , beta Catenina/farmacologia , Aptâmeros de Nucleotídeos/farmacologia , Aptâmeros de Nucleotídeos/metabolismo , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Proteínas Wnt/farmacologia , Proliferação de Células , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/farmacologia , Fatores de Transcrição/metabolismo , Fatores de Transcrição/farmacologia
6.
Prog Retin Eye Res ; 95: 101136, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36400670

RESUMO

Glaucoma is a leading cause of irreversible blindness worldwide and is characterized by a slow, progressive, and multifactorial degeneration of retinal ganglion cells (RGCs) and their axons, resulting in vision loss. Despite its high prevalence in individuals 60 years of age and older, the causing factors contributing to glaucoma progression are currently not well characterized. Intraocular pressure (IOP) is the only proven treatable risk factor. However, lowering IOP is insufficient for preventing disease progression. One of the significant interests in glaucoma pathogenesis is understanding the structural and functional impairment of mitochondria in RGCs and their axons and synapses. Glaucomatous risk factors such as IOP elevation, aging, genetic variation, neuroinflammation, neurotrophic factor deprivation, and vascular dysregulation, are potential inducers for mitochondrial dysfunction in glaucoma. Because oxidative phosphorylation stress-mediated mitochondrial dysfunction is associated with structural and functional impairment of mitochondria in glaucomatous RGCs, understanding the underlying mechanisms and relationship between structural and functional alterations in mitochondria would be beneficial to developing mitochondria-related neuroprotection in RGCs and their axons and synapses against glaucomatous neurodegeneration. Here, we review the current studies focusing on mitochondrial dynamics-based structural and functional alterations in the mitochondria of glaucomatous RGCs and therapeutic strategies to protect RGCs against glaucomatous neurodegeneration.


Assuntos
Glaucoma , Doenças do Nervo Óptico , Humanos , Células Ganglionares da Retina/patologia , Dinâmica Mitocondrial , Pressão Intraocular , Doenças do Nervo Óptico/etiologia
7.
Arterioscler Thromb Vasc Biol ; 43(2): 323-329, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36453276

RESUMO

BACKGROUND: Reprogramming of monocytes and macrophage manifests in hyperinflammatory responses and chronification of inflammation in atherosclerosis. Recent studies focused on epigenetic, transcriptional, and metabolic alterations that characterize trained immunity. However, the underlying effector mechanisms driving the hyperinflammatory response of reprogrammed macrophages remain unclear. We hypothesized that the plasma membrane of atherosclerotic lesion macrophages undergoes reprogramming to maintain inflammarafts, enlarged lipid rafts (LR) serving as a platform for assembly of inflammatory receptor complexes. METHODS: Single-cell suspensions from the aortae of Western diet-fed Ldlr-/- mice were gated for BODIPY-high foamy and BODIPY-low nonfoamy F4/80 macrophages by flow cytometry. Inflammarafts were characterized by increased levels of LR, TLR4 (toll-like receptor-4) localization to LR, TLR4 dimers, and the proximity between TLR2, TLR1, and CD36. In a cellular model of trained immunity, LR, TLR4 dimers, and the inflammatory response were measured in bone marrow-derived macrophages subjected to a 24-hour treatment with LPS (lipopolysaccharide) or OxLDL (oxidized low-density lipoprotein), followed by a 6-day wash-out period. RESULTS: Nonfoamy macrophages, which constituted ≈40% of macrophages in atherosclerotic lesions, expressed significantly higher levels of LR and TLR4 dimers, as well as proximity ligation signals for TLR4-LR, TLR2-CD36, and TLR2-TLR1 complexes, compared with foamy macrophages. These inflammaraft measures associated, to a different degree, with plasma cholesterol and inflammatory cytokines, as well as the size of the atherosclerotic lesions and necrotic cores. The bone marrow-derived macrophages trained with LPS simulated nonfoamy atherosclerotic lesion macrophages and continued to express inflammarafts and inflammatory genes for 6 days after LPS removal and displayed a hyperinflammatory response to Pam3CSK4, a TLR2/TLR1 agonist. OxLDL-exposed, lipid-laden macrophages did not express inflammarafts. CONCLUSIONS: Our data support the hypothesis that persistent inflammarafts in nonfoamy macrophages in atherosclerotic lesions serve as effectors of macrophage reprogramming into a hyperinflammatory phenotype.


Assuntos
Aterosclerose , Células Espumosas , Camundongos , Animais , Células Espumosas/patologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Lipopolissacarídeos , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Receptor 1 Toll-Like/metabolismo , Macrófagos/metabolismo , Aterosclerose/patologia , Lipoproteínas LDL/metabolismo , Antígenos CD36/genética , Antígenos CD36/metabolismo
8.
Front Pain Res (Lausanne) ; 3: 1018800, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36387416

RESUMO

Millions of people suffer from arthritis worldwide, consistently struggling with daily activities due to debilitating pain evoked by this disease. Perhaps the most intensively investigated type of inflammatory arthritis is rheumatoid arthritis (RA), where, despite considerable advances in research and clinical management, gaps regarding the neuroimmune interactions that guide inflammation and chronic pain in this disease remain to be clarified. The pain and inflammation associated with arthritis are not isolated to the joints, and inflammatory mechanisms induced by different immune and glial cells in other tissues may affect the development of chronic pain that results from the disease. This review aims to provide an overview of the state-of-the-art research on the roles that innate immune, and glial cells play in the onset and maintenance of arthritis-associated pain, reviewing nociceptive pathways from the joint through the dorsal root ganglion, spinal circuits, and different structures in the brain. We will focus on the cellular mechanisms related to neuroinflammation and pain, and treatments targeting these mechanisms from the periphery and the CNS. A comprehensive understanding of the role these cells play in peripheral inflammation and initiation of pain and the central pathways in the spinal cord and brain will facilitate identifying new targets and pathways to aide in developing therapeutic strategies to treat joint pain associated with RA.

9.
Nanomaterials (Basel) ; 12(19)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36234481

RESUMO

MoS2 nanoscrolls that have inner core radii of ∼250 nm are generated from MoS2 monolayers, and the optical and transport band gaps of the nanoscrolls are investigated. Photoluminescence spectroscopy reveals that a MoS2 monolayer, originally a direct gap semiconductor (∼1.85 eV (optical)), changes into an indirect gap semiconductor (∼1.6 eV) upon scrolling. The size of the indirect gap for the MoS2 nanoscroll is larger than that of a MoS2 bilayer (∼1.54 eV), implying a weaker interlayer interaction between concentric layers of the MoS2 nanoscroll compared to Bernal-stacked MoS2 few-layers. Transport measurements on MoS2 nanoscrolls incorporated into ambipolar ionic-liquid-gated transistors yielded a band gap of ∼1.9 eV. The difference between the transport and optical gaps indicates an exciton binding energy of 0.3 eV for the MoS2 nanoscrolls. The rolling up of 2D atomic layers into nanoscrolls introduces a new type of quasi-1D nanostructure and provides another way to modify the band gap of 2D materials.

10.
Sensors (Basel) ; 21(23)2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34883963

RESUMO

The seat comfort of automobiles is one of the significant factors for determining the driver's fatigue, emotional experience, and individual space (which captures their individuality, rather than just a means of transportation in modern society). Conventional automobile seats could not provide seating comfort suitable for all drivers, in the form of seats that fit each driver's body type and the difficulty of meeting individual needs. This study proposes self-shape adjustable (the SSA seats) seats that improve the sitting comfort, safety, and secure the stability, by adjusting shape fit to the driver's body type. The SSA seats transforms the seat itself, in a way that improves the distribution of contact pressure and reduces sitting fatigue, with the pneumatic system. The transformed seats provide better sitting comfort and safety than the conventional automobile seat, by providing a seat shape suitable for the body shape of all users. It was verified that the SSA seats, proposed in this paper, have a uniform and improved pressure distribution, compared to the conventional seat, in various sitting postures; the contact area between the seat and user is enlarged, and the pressure concentrated on the ischial bone is lowered. In addition, it was proven (through user evaluation) that quantitative evaluation verification was the same as qualitative evaluation results.


Assuntos
Ergonomia , Postura Sentada , Automóveis , Desenho de Equipamento , Postura
11.
J Exp Med ; 218(7)2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-33970188

RESUMO

Neuroinflammation is a major component in the transition to and perpetuation of neuropathic pain states. Spinal neuroinflammation involves activation of TLR4, localized to enlarged, cholesterol-enriched lipid rafts, designated here as inflammarafts. Conditional deletion of cholesterol transporters ABCA1 and ABCG1 in microglia, leading to inflammaraft formation, induced tactile allodynia in naive mice. The apoA-I binding protein (AIBP) facilitated cholesterol depletion from inflammarafts and reversed neuropathic pain in a model of chemotherapy-induced peripheral neuropathy (CIPN) in wild-type mice, but AIBP failed to reverse allodynia in mice with ABCA1/ABCG1-deficient microglia, suggesting a cholesterol-dependent mechanism. An AIBP mutant lacking the TLR4-binding domain did not bind microglia or reverse CIPN allodynia. The long-lasting therapeutic effect of a single AIBP dose in CIPN was associated with anti-inflammatory and cholesterol metabolism reprogramming and reduced accumulation of lipid droplets in microglia. These results suggest a cholesterol-driven mechanism of regulation of neuropathic pain by controlling the TLR4 inflammarafts and gene expression program in microglia and blocking the perpetuation of neuroinflammation.


Assuntos
Colesterol/metabolismo , Microglia/metabolismo , Neuralgia/metabolismo , Medula Espinal/metabolismo , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Transporte Biológico/fisiologia , Linhagem Celular , Células HEK293 , Humanos , Inflamação/metabolismo , Masculino , Microdomínios da Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica/fisiologia , Transdução de Sinais/fisiologia
12.
Arterioscler Thromb Vasc Biol ; 41(2): e82-e96, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33356389

RESUMO

OBJECTIVE: Atherosclerotic lesions are often characterized by accumulation of OxLDL (oxidized low-density lipoprotein), which is associated with vascular inflammation and lesion vulnerability to rupture. Extracellular AIBP (apolipoprotein A-I binding protein; encoded by APOA1BP gene), when secreted, promotes cholesterol efflux and regulates lipid rafts dynamics, but its role as an intracellular protein in mammalian cells remains unknown. The aim of this work was to determine the function of intracellular AIBP in macrophages exposed to OxLDL and in atherosclerotic lesions. Approach and Results: Using a novel monoclonal antibody against human and mouse AIBP, which are highly homologous, we demonstrated robust AIBP expression in human and mouse atherosclerotic lesions. We observed significantly reduced autophagy in bone marrow-derived macrophages, isolated from Apoa1bp-/- compared with wild-type mice, which were exposed to OxLDL. In atherosclerotic lesions from Apoa1bp-/- mice subjected to Ldlr knockdown and fed a Western diet, autophagy was reduced, whereas apoptosis was increased, when compared with that in wild-type mice. AIBP expression was necessary for efficient control of reactive oxygen species and cell death and for mitochondria quality control in macrophages exposed to OxLDL. Mitochondria-localized AIBP, via its N-terminal domain, associated with E3 ubiquitin-protein ligase PARK2 (Parkin), MFN (mitofusin)1, and MFN2, but not BNIP3 (Bcl2/adenovirus E1B 19-kDa-interacting protein-3), and regulated ubiquitination of MFN1 and MFN2, key components of mitophagy. CONCLUSIONS: These data suggest that intracellular AIBP is a new regulator of autophagy in macrophages. Mitochondria-localized AIBP augments mitophagy and participates in mitochondria quality control, protecting macrophages against cell death in the context of atherosclerosis.


Assuntos
Doenças da Aorta/metabolismo , Aterosclerose/metabolismo , Lipoproteínas LDL/toxicidade , Macrófagos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Fosfoproteínas/metabolismo , Racemases e Epimerases/metabolismo , Animais , Doenças da Aorta/genética , Doenças da Aorta/patologia , Apoptose/efeitos dos fármacos , Aterosclerose/genética , Aterosclerose/patologia , Autofagossomos/efeitos dos fármacos , Autofagossomos/metabolismo , Autofagossomos/patologia , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Doenças das Artérias Carótidas/metabolismo , Doenças das Artérias Carótidas/patologia , Modelos Animais de Doenças , Células HEK293 , Células Hep G2 , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Fosfoproteínas/genética , Racemases e Epimerases/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
13.
Redox Biol ; 37: 101703, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32896719

RESUMO

Glaucoma is a leading cause of blindness worldwide in individuals 60 years of age and older. Despite its high prevalence, the factors contributing to glaucoma progression are currently not well characterized. Glia-driven neuroinflammation and mitochondrial dysfunction play critical roles in glaucomatous neurodegeneration. Here, we demonstrated that elevated intraocular pressure (IOP) significantly decreased apolipoprotein A-I binding protein (AIBP; gene name Apoa1bp) in retinal ganglion cells (RGCs), but resulted in upregulation of TLR4 and IL-1ß expression in Müller glia endfeet. Apoa1bp-/- mice had impaired visual function and Müller glia characterized by upregulated TLR4 activity, impaired mitochondrial network and function, increased oxidative stress and induced inflammatory responses. We also found that AIBP deficiency compromised mitochondrial network and function in RGCs and exacerbated RGC vulnerability to elevated IOP. Administration of recombinant AIBP prevented RGC death and inhibited inflammatory responses and cytokine production in Müller glia in vivo. These findings indicate that AIBP protects RGCs against glia-driven neuroinflammation and mitochondrial dysfunction in glaucomatous neurodegeneration and suggest that recombinant AIBP may be a potential therapeutic agent for glaucoma.


Assuntos
Glaucoma , Células Ganglionares da Retina , Animais , Modelos Animais de Doenças , Glaucoma/tratamento farmacológico , Glaucoma/metabolismo , Camundongos , Mitocôndrias , Células Ganglionares da Retina/metabolismo , Regulação para Cima
14.
Arterioscler Thromb Vasc Biol ; 40(10): 2346-2359, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32787522

RESUMO

OBJECTIVE: AIBP (apolipoprotein A-I binding protein) is an effective and selective regulator of lipid rafts modulating many metabolic pathways originating from the rafts, including inflammation. The mechanism of action was suggested to involve stimulation by AIBP of cholesterol efflux, depleting rafts of cholesterol, which is essential for lipid raft integrity. Here we describe a different mechanism contributing to the regulation of lipid rafts by AIBP. Approach and Results: We demonstrate that modulation of rafts by AIBP may not exclusively depend on the rate of cholesterol efflux or presence of the key regulator of the efflux, ABCA1 (ATP-binding cassette transporter A-I). AIBP interacted with phosphatidylinositol 3-phosphate, which was associated with increased abundance and activation of Cdc42 and rearrangement of the actin cytoskeleton. Cytoskeleton rearrangement was accompanied with reduction of the abundance of lipid rafts, without significant changes in the lipid composition of the rafts. The interaction of AIBP with phosphatidylinositol 3-phosphate was blocked by AIBP substrate, NADPH (nicotinamide adenine dinucleotide phosphate), and both NADPH and silencing of Cdc42 interfered with the ability of AIBP to regulate lipid rafts and cholesterol efflux. CONCLUSIONS: Our findings indicate that an underlying mechanism of regulation of lipid rafts by AIBP involves PIP-dependent rearrangement of the cytoskeleton.


Assuntos
Citoesqueleto de Actina/enzimologia , Colesterol/metabolismo , Microdomínios da Membrana/enzimologia , Racemases e Epimerases/metabolismo , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Citoesqueleto de Actina/genética , Animais , Células HeLa , Humanos , Microdomínios da Membrana/genética , Camundongos , Fosfatidilinositol 3-Quinase/metabolismo , Transdução de Sinais , Células THP-1 , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo
15.
Cell Death Dis ; 11(4): 254, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32312949

RESUMO

Impairment of mitochondrial structure and function is strongly linked to glaucoma pathogenesis. Despite the widely appreciated disease relevance of mitochondrial dysfunction and loss, the molecular mechanisms underlying mitochondrial fragmentation and metabolic stress in glaucoma are poorly understood. We demonstrate here that glaucomatous retinal ganglion cells (RGCs) show loss of A-kinase anchoring protein 1 (AKAP1), activation of calcineurin (CaN) and reduction of dynamin-related protein 1 (Drp1) phosphorylation at serine 637 (Ser637). These findings suggest that AKAP1-mediated phosphorylation of Drp1 at Ser637 has a critical role in RGC survival in glaucomatous neurodegeneration. Male mice lacking AKAP1 show increases in CaN and total Drp1 levels, as well as a decrease in Drp1 phosphorylation at Ser637 in the retina. Ultrastructural analysis of mitochondria shows that loss of AKAP1 triggers mitochondrial fragmentation and loss, as well as mitophagosome formation in RGCs. Loss of AKAP1 deregulates oxidative phosphorylation (OXPHOS) complexes (Cxs) by increasing CxII and decreasing CxIII-V, leading to metabolic and oxidative stress. Also, loss of AKAP1 decreases Akt phosphorylation at Serine 473 (Ser473) and threonine 308 (Thr308) and activates the Bim/Bax signaling pathway in the retina. These results suggest that loss of AKAP1 has a critical role in RGC dysfunction by decreasing Drp1 phosphorylation at Ser637, deregulating OXPHOS, decreasing Akt phosphorylation at Ser473 and Thr308, and activating the Bim/Bax pathway in glaucomatous neurodegeneration. Thus, we propose that overexpression of AKAP1 or modulation of Drp1 phosphorylation at Ser637 are potential therapeutic strategies for neuroprotective intervention in glaucoma and other mitochondria-related optic neuropathies.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Dinaminas/metabolismo , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/fisiologia , Animais , Camundongos Transgênicos , Estresse Oxidativo/fisiologia , Células Ganglionares da Retina/metabolismo , Transdução de Sinais/fisiologia
16.
Int J Biol Macromol ; 155: 439-446, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32220643

RESUMO

Ionic liquids (ILs) are known to provide stability to biomolecules. ILs are also widely used in the fields of chemical engineering, biological engineering, chemistry, and biochemistry because they facilitate enzyme catalyzed reactions and enhance their conversion rate. In this work, we have evaluated the influence of alkyl chain substitution of ammonium ILs such as diethylammonium dihydrogen phosphate (DEAP) and triethylammonium hydrogen phosphate (TEAP) for the stability and activity of the tobacco etch virus (TEV) protease. Further, we performed molecular dynamics (MD) simulations to calculate the RMSD (root mean square deviation) for TEV and TEV + ILs. Experimental and simulations results show that TEV is more stable in the presence of TEAP than DEAP. Whereas, TEV protease activity for the cleavage of fusion proteins is preserved in the presence of DEAP while lost in the presence of TEAP. Hence, DEAP IL can serve as alternative solvents for the stability of the TEV protease with preserved activity. To the best of our knowledge, this is first study to show that ILs can stabilize and maintain the TEV protease cleavage activity.


Assuntos
Compostos de Amônio/química , Endopeptidases/química , Endopeptidases/metabolismo , Líquidos Iônicos/química , Estabilidade Enzimática , Modelos Moleculares , Simulação de Dinâmica Molecular , Conformação Proteica , Solventes/química
18.
mBio ; 11(1)2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31964734

RESUMO

Apolipoprotein A-I binding protein (AIBP) is a protein involved in regulation of lipid rafts and cholesterol efflux. AIBP has been suggested to function as a protective factor under several sets of pathological conditions associated with increased abundance of lipid rafts, such as atherosclerosis and acute lung injury. Here, we show that exogenously added AIBP reduced the abundance of lipid rafts and inhibited HIV replication in vitro as well as in HIV-infected humanized mice, whereas knockdown of endogenous AIBP increased HIV replication. Endogenous AIBP was much more abundant in activated T cells than in monocyte-derived macrophages (MDMs), and exogenous AIBP was much less effective in T cells than in MDMs. AIBP inhibited virus-cell fusion, specifically targeting cells with lipid rafts mobilized by cell activation or Nef-containing exosomes. MDM-HIV fusion was sensitive to AIBP only in the presence of Nef provided by the virus or exosomes. Peripheral blood mononuclear cells from donors with the HLA-B*35 genotype, associated with rapid progression of HIV disease, bound less AIBP than cells from donors with other HLA genotypes and were not protected by AIBP from rapid HIV-1 replication. These results provide the first evidence for the role of Nef exosomes in regulating HIV-cell fusion by modifying lipid rafts and suggest that AIBP is an innate factor that restricts HIV replication by targeting lipid rafts.IMPORTANCE Apolipoprotein A-I binding protein (AIBP) is a recently identified innate anti-inflammatory factor. Here, we show that AIBP inhibited HIV replication by targeting lipid rafts and reducing virus-cell fusion. Importantly, AIBP selectively reduced levels of rafts on cells stimulated by an inflammatory stimulus or treated with extracellular vesicles containing HIV-1 protein Nef without affecting rafts on nonactivated cells. Accordingly, fusion of monocyte-derived macrophages with HIV was sensitive to AIBP only in the presence of Nef. Silencing of endogenous AIBP significantly upregulated HIV-1 replication. Interestingly, HIV-1 replication in cells from donors with the HLA-B*35 genotype, associated with rapid progression of HIV disease, was not inhibited by AIBP. These results suggest that AIBP is an innate anti-HIV factor that targets virus-cell fusion.

19.
J Cosmet Dermatol ; 19(4): 970-976, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31353789

RESUMO

BACKGROUND: Vitamin C (also known as L-ascorbic acid) plays a critical role in reactive oxygen species (ROS) reduction and cell regeneration by protecting cell from oxidative stress. Although vitamin C is widely used in cosmetic and therapeutic markets, there is considerable evidence that vitamin C easily undergoes oxidation by air, pH, temperature, and UV light upon storage. This deficiency of vitamin C decreases its potency as an antioxidant and reduces the shelf-life of products containing vitamin C as its ingredient. To overcome the deficiency of vitamin C, we have developed Aptamin C, an innovative DNA aptamer maximizing the antioxidant efficacy of vitamin C by binding to the reduced form of vitamin C and delaying its oxidation. METHODS: Binding of Aptamin C with vitamin C was determined using ITC analysis. ITC experiment was performed 0.2 mmol/L vitamin C that was injected 25 times in 2 µL aliquots into the 1.8 mL sample cell containing the Aptamin C at a concentration of 0.02 mmol/L. The data were fitted to a one-site binding isotherm using with origin program for ITC v.5.0. RESULTS: To investigate the effect of Aptamin C and vitamin C complex in human skins, both in vitro and clinical tests were performed. We observed that the complex of Aptamin C and vitamin C was significantly effective in wrinkle improvement, whitening effect, and hydration increase. In the clinical test, subjects treated with the complex showed dramatic improvement in skin irritation and itching. No adverse reaction was presented by Aptamin C complex in the test. CONCLUSION: Taken together, these results showed that Aptamin C, an innovative novel compound, should potentially be served as a key cosmeceutical ingredient for a range of skin conditions.


Assuntos
Antioxidantes/administração & dosagem , Aptâmeros de Nucleotídeos/administração & dosagem , Ácido Ascórbico/administração & dosagem , Cosmecêuticos/administração & dosagem , Pele/efeitos dos fármacos , Antioxidantes/efeitos adversos , Antioxidantes/química , Aptâmeros de Nucleotídeos/efeitos adversos , Aptâmeros de Nucleotídeos/química , Ácido Ascórbico/efeitos adversos , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cosmecêuticos/efeitos adversos , Cosmecêuticos/química , Composição de Medicamentos/métodos , Armazenamento de Medicamentos , Feminino , Fibroblastos , Humanos , Pessoa de Meia-Idade , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Pele/citologia , Envelhecimento da Pele/efeitos dos fármacos , Testes de Irritação da Pele , Pigmentação da Pele/efeitos dos fármacos , Perda Insensível de Água/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA