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1.
J Nanobiotechnology ; 22(1): 290, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38802884

RESUMO

Corneal neovascularization (CNV) is one of the common blinding factors worldwide, leading to reduced vision or even blindness. However, current treatments such as surgical intervention and anti-VEGF agent therapy still have some shortcomings or evoke some adverse effects. Recently, SU6668, an inhibitor targeting angiogenic tyrosine kinases, has demonstrated growth inhibition of neovascularization. But the hydrophobicity and low ocular bioavailability limit its application in cornea. Hereby, we proposed the preparation of SU6668 pure nanoparticles (NanoSU6668; size ~135 nm) using a super-stable pure-nanomedicine formulation technology (SPFT), which possessed uniform particle size and excellent aqueous dispersion at 1 mg/mL. Furthermore, mesenchymal stem cell membrane vesicle (MSCm) was coated on the surface of NanoSU6668, and then conjugated with TAT cell penetrating peptide, preparing multifunctional TAT-MSCm@NanoSU6668 (T-MNS). The T-MNS at a concentration of 200 µg/mL was treated for CNV via eye drops, and accumulated in blood vessels with a high targeting performance, resulting in elimination of blood vessels and recovery of cornea transparency after 4 days of treatment. Meanwhile, drug safety test confirmed that T-MNS did not cause any damage to cornea, retina and other eye tissues. In conclusion, the T-MNS eye drop had the potential to treat CNV effectively and safely in a low dosing frequency, which broke new ground for CNV theranostics.


Assuntos
Córnea , Neovascularização da Córnea , Nanopartículas , Soluções Oftálmicas , Neovascularização da Córnea/tratamento farmacológico , Animais , Nanopartículas/química , Soluções Oftálmicas/química , Córnea/metabolismo , Córnea/efeitos dos fármacos , Camundongos , Inibidores da Angiogênese/química , Inibidores da Angiogênese/uso terapêutico , Inibidores da Angiogênese/farmacologia , Tamanho da Partícula , Humanos , Masculino , Camundongos Endogâmicos C57BL , Coelhos
2.
Antioxidants (Basel) ; 13(4)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38671870

RESUMO

Dry eye disease (DED) is a multifactorial condition affecting the ocular surface. It is characterized by loss of tear film homeostasis and accompanied by ocular symptoms that may potentially result in damage to the ocular surface and even vision loss. Unmodifiable risk factors for DED mainly include aging, hormonal changes, and lifestyle issues such as reduced sleep duration, increased screen exposure, smoking, and ethanol consumption. As its prevalence continues to rise, DED has garnered considerable attention, prompting the exploration of potential new therapeutic targets. Recent studies have found that when the production of ROS exceeds the capacity of the antioxidant defense system on the ocular surface, oxidative stress ensues, leading to cellular apoptosis and further oxidative damage. These events can exacerbate inflammation and cellular stress responses, further increasing ROS levels and promoting a vicious cycle of oxidative stress in DED. Therefore, given the central role of reactive oxygen species in the vicious cycle of inflammation in DED, strategies involving antioxidants have emerged as a novel approach for its treatment. This review aims to enhance our understanding of the intricate relationship between oxidative stress and DED, thereby providing directions to explore innovative therapeutic approaches for this complex ocular disorder.

3.
Adv Sci (Weinh) ; : e2304948, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38072664

RESUMO

Resorcinol-formaldehyde (RF) resin represents a promising visible-light responding photocatalyst for oxygen reduction reaction (ORR) toward H2 O2 production. However, its photocatalytic ORR activity toward H2 O2 generation is still unsatisfied for practical application. Herein, 3-hydroxythiophenol-formaldehyde (3-HTPF) resin microspheres synthesized through polycondensation reaction between 3-HTP and formaldehyde at room temperature and subsequent hydrothermal treatment exhibit enhanced photocatalytic ORR activity is reported. The experimental results show that the partial substitution of hydroxy group (─OH) by sulfhydryl one (─SH) through using 3-HTP to replace resorcinol could slow the rates of nucleation and growth of the resin particles and lead to strongly π-stacked architecture in 3-HTPF. The introduction of ─SH group can also improve adsorption ability of 3-HTPF to O2 molecules and enhance ORR catalytic activity of the photocatalysts. Stronger built-in electric field, better adsorption ability to O2 molecules, and increased surface catalytic activity collectively boost photocatalytic activity of 3-HTPF microspheres. As a result, H2 O2 production rate of 2010 µm h-1 is achieved over 3-HTPF microspheres at 273 K, which is 3.4 times larger than that obtained using RF submicrospheres (591 µm h-1 ). The rational substituent group modulation provides a new strategy for designing polymeric photocatalysts at the molecular level toward high-efficiency artificial photosynthesis.

4.
Am J Pathol ; 193(11): 1863-1878, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37634709

RESUMO

Severe dry eye (SDE) can cause grievous damage to the ocular surface and result in vision impairment and even blindness. To investigate the fate of limbal stem cells in SDE and the underlying mechanism, the current study established an SDE rat model by removing the extraorbital and infraorbital lacrimal glands and maintaining them in a low-humidity environment. One month after the surgery, aqueous tear secretion was reduced dramatically, blood vessels invaded into the central cornea, and inflammatory cells infiltrated into the limbal stroma. The expressions of keratin 12 and paired box gene 6 were down-regulated dramatically, while those of keratin 10, small proline-rich protein 1b, and mucin 5AC were up-regulated in the corneal epithelium of the SDE rats. Cell proliferation in the limbal epithelium was up-regulated, while the stem/progenitor marker adenosine 5'-triphosphate-binding cassette member 2 and the limbal epithelial colony-forming efficiency were decreased in the SDE condition. Furthermore, the p38 mitogen-activated protein kinase signaling pathway was activated in the limbal corneal epithelium of SDE rats. The abnormal differentiation and stemness loss in the corneal epithelium could be reversed upon treatment with a p38 inhibitor in a SDE in vivo model and in vitro hyperosmolar corneal epithelial culture conditions. These data suggest that SDE can lead to limbal stem cell dysfunction, and p38 mitogen-activated protein kinase signaling pathway activation plays an essential role in this process.

5.
Tissue Eng Part A ; 28(23-24): 977-989, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36066335

RESUMO

Tissue-engineered corneal epithelium transplantation is effective treatment for severe limbal stem cell deficiency (LSCD), while epithelial terminal differentiation, tans-differentiation, and insufficient stem cell during construction affect the quality of tissue-engineered corneal epithelium. In this study, we applied SB203580 in the culture medium to downregulate the p38 mitogen-activated protein kinase (MAPK) signaling pathway during construction of tissue-engineered corneal epithelium. With application of SB203580, tissue-engineered corneal epithelium showed enhanced strength and condensed structure. The expression of progenitor cell markers ATP-binding cassette sub-family G member 2, tumor protein p63, keratin 14, and Wnt family member 7A was increased, differentiation markers keratin 12, paired box 6, keratin 10, and keratin 13 and trans-differentiation markers actin alpha 2, smooth muscle and snail family transcriptional repressor 1 was decreased, while cell junction markers claudin 1 and cadherin 1 was increased in the tissue-engineered corneal epithelium. The Wnt/catenin beta 1 signaling pathway was upregulated in the epithelium after p38 MAPK inhibition. Transplantation of tissue-engineered corneal epithelium treated with SB203580 to rabbit LSCD model showed faster wound healing and improved epithelial quality. We conclude that downregulation of p38 MAPK signaling pathway helps maintain the stemness and prevent terminal differentiation and abnormal differentiation of corneal epithelial cells during epithelium construction process, and thus can improve the quality of tissue-engineered corneal epithelium. Impact statement Downregulation of p38 MAPK signaling pathway helps maintain the self-renewal of limbal stem cells and prevents terminal differentiation and abnormal differentiation of corneal epithelial cells. Small molecules modulating p38 MAPK signaling pathway ameliorate tissue-engineered corneal epithelium.


Assuntos
Epitélio Corneano , Limbo da Córnea , Animais , Coelhos , Limbo da Córnea/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/análise , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Regulação para Baixo , Transdução de Sinais
6.
JCI Insight ; 7(7)2022 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-35192548

RESUMO

Clinical outcomes in colorectal cancer (CRC) correlate with T cell infiltrates, but the specific contributions of heterogenous T cell types remain unclear. To investigate the diverse function of T cells in CRC, we profiled 37,931 T cells from tumors and adjacent normal colon of 16 patients with CRC with respect to transcriptome, TCR sequence, and cell surface markers. Our analysis identified phenotypically and functionally distinguishable effector T cell types. We employed single-cell gene signatures from these T cell subsets to query the TCGA database to assess their prognostic significance. We found 2 distinct cytotoxic T cell types. GZMK+KLRG1+ cytotoxic T cells were enriched in CRC patients with good outcomes. GNLY+CD103+ cytotoxic T cells with a dysfunctional phenotype were not associated with good outcomes, despite coexpression of CD39 and CD103, markers that denote tumor reactivity. We found 2 distinct Treg subtypes associated with opposite outcomes. While total Tregs were associated with good outcomes, CD38+ Tregs were associated with bad outcomes independently of stage and possessed a highly suppressive phenotype, suggesting that they inhibit antitumor immunity in CRC. These findings highlight the potential utility of these subpopulations in predicting outcomes and support the potential for novel therapies directed at CD38+ Tregs or CD8+CD103+ T cells.


Assuntos
Neoplasias Colorretais , Análise de Célula Única , Linfócitos T CD8-Positivos , Neoplasias Colorretais/metabolismo , Humanos , Prognóstico , Subpopulações de Linfócitos T
7.
Nature ; 597(7877): 549-554, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34497417

RESUMO

Monoclonal antibody therapies targeting tumour antigens drive cancer cell elimination in large part by triggering macrophage phagocytosis of cancer cells1-7. However, cancer cells evade phagocytosis using mechanisms that are incompletely understood. Here we develop a platform for unbiased identification of factors that impede antibody-dependent cellular phagocytosis (ADCP) using complementary genome-wide CRISPR knockout and overexpression screens in both cancer cells and macrophages. In cancer cells, beyond known factors such as CD47, we identify many regulators of susceptibility to ADCP, including the poorly characterized enzyme adipocyte plasma membrane-associated protein (APMAP). We find that loss of APMAP synergizes with tumour antigen-targeting monoclonal antibodies and/or CD47-blocking monoclonal antibodies to drive markedly increased phagocytosis across a wide range of cancer cell types, including those that are otherwise resistant to ADCP. Additionally, we show that APMAP loss synergizes with several different tumour-targeting monoclonal antibodies to inhibit tumour growth in mice. Using genome-wide counterscreens in macrophages, we find that the G-protein-coupled receptor GPR84 mediates enhanced phagocytosis of APMAP-deficient cancer cells. This work reveals a cancer-intrinsic regulator of susceptibility to antibody-driven phagocytosis and, more broadly, expands our knowledge of the mechanisms governing cancer resistance to macrophage phagocytosis.


Assuntos
Citotoxicidade Celular Dependente de Anticorpos/genética , Sistemas CRISPR-Cas , Citofagocitose/genética , Macrófagos/imunologia , Neoplasias/imunologia , Neoplasias/patologia , Animais , Anticorpos Monoclonais/imunologia , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antígenos de Neoplasias/imunologia , Antígeno CD47/antagonistas & inibidores , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Edição de Genes , Técnicas de Inativação de Genes , Humanos , Linfoma de Células T/imunologia , Linfoma de Células T/patologia , Macrófagos/citologia , Macrófagos/metabolismo , Masculino , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Camundongos , Receptores Acoplados a Proteínas G/metabolismo
8.
J Cell Physiol ; 236(5): 3660-3674, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33034385

RESUMO

The underlying mechanisms of complement activation in Stargardt disease type 1 (STGD1) and age-related macular degeneration (AMD) are not fully understood. Overaccumulation of all-trans-retinal (atRAL) has been proposed as the pathogenic factor in both diseases. By incubating retinal pigment epithelium (RPE) cells with atRAL, we showed that C5b-9 membrane attack complexes (MACs) were generated mainly through complement alternative pathway. An increase in complement factor B (CFB) expression as well as downregulation of complement regulatory proteins CD46, CD55, CD59, and CFH were observed in RPE cells after atRAL treatment. Furthermore, interleukin-1ß production was provoked in both atRAL-treated RPE cells and microglia/macrophages. Coincubation of RPE cells with interleukin-1 receptor antagonist (IL1Ra) and atRAL ameliorated complement activation and downregulated CFB expression by attenuating both p38 and c-Jun N-terminal kinase (JNK) signaling pathways. Our findings demonstrate that atRAL induces an autocrine/paracrine IL-1/IL-1R signaling to promote complement alternative pathway activation in RPE cells and provide a novel perspective on the pathomechanism of macular degeneration.


Assuntos
Ativação do Complemento/efeitos dos fármacos , Via Alternativa do Complemento/efeitos dos fármacos , Interleucina-1/metabolismo , Receptores de Interleucina-1/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Retinaldeído/farmacologia , Transdução de Sinais , Acetilcisteína/farmacologia , Animais , Células Cultivadas , Fator B do Complemento/metabolismo , Regulação para Baixo , Humanos , Interleucina-1/genética , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Microglia/efeitos dos fármacos , Microglia/metabolismo , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Modelos Biológicos , Epitélio Pigmentado da Retina/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Suínos , Transcrição Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
9.
Adv Sci (Weinh) ; 7(18): 2001299, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32999841

RESUMO

The gut-brain axis has attracted increasing attention in recent years, fueled by accumulating symptomatic, physiological, and pathological findings. In this study, the aggregation and toxicity of amyloid beta (Aß), the pathogenic peptide associated with Alzheimer's disease (AD), seeded by FapC amyloid fragments (FapCS) of Pseudomonas aeruginosa that colonizes the gut microbiome through infections are examined. FapCS display favorable binding with Aß and a catalytic capacity in seeding the peptide amyloidosis. Upon seeding, twisted Aß fibrils assume a much-shortened periodicity approximating that of FapC fibrils, accompanied by a 37% sharp rise in the fibrillar diameter, compared with the control. The robust seeding capacity for Aß by FapCS and the biofilm fragments derived from P. aeruginosa entail abnormal behavior pathology and immunohistology, as well as impaired cognitive function of zebrafish. Together, the data offer the first concrete evidence of structural integration and inheritance in peptide cross-seeding, a crucial knowledge gap in understanding the pathological correlations between different amyloid diseases. The catalytic role of infectious bacteria in promoting Aß amyloidosis may be exploited as a potential therapeutic target, while the altered mesoscopic signatures of Aß fibrils may serve as a prototype for molecular assembly and a biomarker for screening bacterial infections in AD.

10.
Nanoscale ; 12(23): 12317-12328, 2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-32490863

RESUMO

Type 2 diabetes (T2D) and Alzheimer's disease (AD) represent two most prevalent amyloid diseases with a significant global burden. Pathologically, T2D and AD are characterized by the presence of amyloid plaques consisting primarily of toxic human islet amyloid polypeptide (IAPP) and amyloid beta (Aß). It has been recently revealed that the gut microbiome plays key functions in the pathological progression of neurological disorders through the production of bacterial endotoxins, such as lipopolysaccharide (LPS). In this study, we examined the catalytic effects of LPS on IAPP and Aß amyloidoses, and further demonstrated their mitigation with zero-dimensional carbon quantum dots (CQDs). Whereas LPS displayed preferred binding with the N-terminus of IAPP and the central hydrophobic core and C-terminus of Aß, CQDs exhibited propensities for the amyloidogenic and C-terminus regions of IAPP and the N-terminus of Aß, accordingly. The inhibitory effect of CQDs was verified by an embryonic zebrafish model exposed to the peptides and LPS, where impaired embryonic hatching was rescued and production of reactive oxygen species in the organism was suppressed by the nanomaterial. This study revealed a robust synergy between LPS and amyloid peptides in toxicity induction, and implicated CQDs as a potential therapeutic against the pathologies of T2D and AD.


Assuntos
Amiloidose , Diabetes Mellitus Tipo 2 , Pontos Quânticos , Amiloide , Peptídeos beta-Amiloides , Animais , Carbono , Humanos , Lipopolissacarídeos , Peixe-Zebra
11.
Chemosphere ; 249: 126141, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062211

RESUMO

Crude oil pollution can cause severe and long-term ecological damage and oil cleanup has become a worldwide challenge. Conventional treatment strategies like in-situ burning, manual skimmer and bioremediation were labor-intensive and time-consuming. The high viscosity of crude oil also posed difficulty for traditional absorbents. Herein, to address these limitations, we designed and fabricated a floating absorbent that was comprised of reduced graphene oxide (RGO), melamine sponge (MS), and a 3D-printed mounting platform. Through a facile one-pot hydrothermal method, graphene oxide (GO) was simultaneously reduced to RGO and loaded in MS (RGO-MS). The resulted RGO-MS composites possess desirable hydrophobicity/oleophilicity for oil absorption with a water contact angle of 122°. The effective light-to-heat conversion allowed the RGO-MS composite to absorb approximately 95 times its own weight of crude oil within 12 min under light irradiation. A 3D-printed mounting platform for RGO-MS composites was further fabricated to improve its applicability and allow easy retrieval. Taking advantages of the RGO's hydrophobicity/oleophilicity and photothermal property, the floating ability of MS, this study demonstrated the real-life applicability of RGO-MS composites for in-situ crude oil cleanup.


Assuntos
Recuperação e Remediação Ambiental/métodos , Grafite/química , Poluição por Petróleo/análise , Petróleo/análise , Poluentes Químicos da Água/análise , Interações Hidrofóbicas e Hidrofílicas , Óxidos , Água , Poluentes Químicos da Água/química
12.
Asian Bioeth Rev ; 12(3): 307-323, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33717340

RESUMO

This study examines the representations of human gene patents in Chinese newspapers. We conducted a qualitative content analysis of news articles published between 2006 and 2017 to identify the major themes in media coverage, ethical considerations, perceptions of risks and benefits, and attitudes towards the patentability of human genes. The results show that two key ethical concerns were expressed by journalists: (1) that it is morally wrong to own or patent human genes and (2) that gene patents could potentially impede patients' access to healthcare services. Nonetheless, the press coverage has tended to be largely favorable (57.8%), rather than opposed (17.8%) to human gene patenting. There were no normative claims that human genes should not be patentable in China, which indicates a generally positive attitude towards patentability in media discourse. Most articles that expressed criticism toward gene patenting discussed challenges in other countries, with significant attention given to the United States Supreme Court's ruling in the Myriad case that invalidated Myriad Genetics' patents on the BRCA1 and BRCA2 genes. Overall, the newspapers were uncritical of the Chinese gene patenting regime. News reporting on the issue was highly suggestive of a strong pro-commercialization stance, although some discussions emphasized potential risks over benefits. Our analysis highlights the need for balanced media reporting on human gene patents in China and a top-down approach to engage the public in substantive discussions on the ethical and societal implications of the existing patent regime.

13.
Sci Bull (Beijing) ; 64(1): 26-35, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30662791

RESUMO

Although much has been learned about the fibrillization kinetics, structure and toxicity of amyloid proteins, the properties of amyloid fibrils beyond the saturation phase are often perceived as chemically and biologically inert, despite evidence suggesting otherwise. To fill this knowledge gap, we examined the physical and biological characteristics of human islet amyloid polypeptide (IAPP) fibrils that were aged up to two months. Not only did aging decrease the toxicity of IAPP fibrils, but the fibrils also sequestered fresh IAPP and suppressed their toxicity in an embryonic zebrafish model. The mechanical properties of IAPP fibrils in different aging stages were probed by atomic force microscopy and sonication, which displayed comparable stiffness but age-dependent fragmentation, followed by self-assembly of such fragments into the largest lamellar amyloid structures reported to date. The dynamic structural and toxicity profiles of amyloid fibrils and plaques suggest that they play active, long-term roles in cell degeneration and may be a therapeutic target for amyloid diseases.

14.
Nanoscale ; 10(42): 19995-20006, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30350837

RESUMO

The development of biocompatible nanomaterials has become a new frontier in the detection, treatment and prevention of human amyloid diseases. Here we demonstrated the use of graphene quantum dots (GQDs) as a potent inhibitor against the in vivo aggregation and toxicity of human islet amyloid polypeptide (IAPP), a hallmark of type 2 diabetes. GQDs initiated contact with IAPP through electrostatic and hydrophobic interactions as well as hydrogen bonding, which subsequently drove the peptide fibrillization off-pathway to eliminate the toxic intermediates. Such interactions, probed in vitro by a thioflavin T kinetic assay, fluorescence quenching, circular dichroism spectroscopy, a cell viability assay and in silico by discrete molecular dynamics simulations, translated to a significant recovery of embryonic zebrafish from the damage elicited by IAPP in vivo, as indicated by improved hatching as well as alleviated reactive oxygen species production, abnormality and mortality of the organism. This study points to the potential of using zero-dimensional nanomaterials for in vivo mitigation of a range of amyloidosis.


Assuntos
Grafite/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Pontos Quânticos/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Embrião não Mamífero/patologia , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/toxicidade , Imagem Óptica , Espectroscopia Fotoeletrônica , Estrutura Secundária de Proteína , Pontos Quânticos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície , Peixe-Zebra/crescimento & desenvolvimento
15.
Small ; 14(47): e1802825, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30369028

RESUMO

Amyloid fibrils generally display chirality, a feature which has rarely been exploited in the development of therapeutics against amyloid diseases. This study reports, for the first time, the use of mesoscopic chiral silica nanoribbons against the in vivo amyloidogenesis of human islet amyloid polypeptide (IAPP), the peptide whose aggregation is implicated in type 2 diabetes. The thioflavin T assay and transmission electron microscopy show accelerated IAPP fibrillization through elimination of the nucleation phase and shortening of the elongation phase by the nanostructures. Coarse-grained simulations offer complementary molecular insights into the acceleration of amyloid aggregation through their nonspecific binding and directional seeding with the nanostructures. This accelerated IAPP fibrillization translates to reduced toxicity, especially for the right-handed silica nanoribbons, as revealed by cell viability, helium ion microscopy, as well as zebrafish embryo survival, developmental, and behavioral assays. This study has implicated the potential of employing chiral nanotechnologies against the mesoscopic enantioselectivity of amyloid proteins and their associated diseases.


Assuntos
Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Nanotubos de Carbono/química , Dióxido de Silício/química , Humanos , Estereoisomerismo
16.
Nano Lett ; 18(9): 5797-5804, 2018 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-30088935

RESUMO

Amyloid diseases are global epidemics with no cure available. Herein, we report a first demonstration of in vivo mitigation of amyloidogenesis using biomimetic nanotechnology. Specifically, the amyloid fragments (ba) of ß-lactoglobulin, a whey protein, were deposited onto the surfaces of carbon nanotubes (baCNT), which subsequently sequestered human islet amyloid polypeptide (IAPP) through functional-pathogenic double-protein coronae. Conformational changes at the ba-IAPP interface were studied by Fourier transform infrared, circular dichroism, and X-ray scattering spectroscopies. baCNT eliminated the toxic IAPP species from zebrafish embryos, as evidenced by the assays of embryonic development, cell morphology, hatching, and survival as well as suppression of oxidative stress. In addition to IAPP, baCNT also displayed high potency against the toxicity of amyloid-ß, thereby demonstrating the broad applicability of this biomimetic nanotechnology and the use of an embryonic zebrafish model for the high-throughput screening of a range of amyloidogenesis and their inhibitors in vivo.


Assuntos
Amiloide/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Lactoglobulinas/química , Nanotubos de Carbono/química , Coroa de Proteína/química , Proteínas do Soro do Leite/química , Amiloide/antagonistas & inibidores , Animais , Modelos Animais de Doenças , Humanos , Estresse Oxidativo , Propriedades de Superfície , Peixe-Zebra/embriologia
17.
Cell Signal ; 51: 222-232, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30102978

RESUMO

Drug repurposing with a better understanding of the underlying mechanism has provided new avenues to find treatment for malignancies. Esophageal adenocarcinoma (EAC) is a rapidly increasing cancer with a dismal 5-year survival rate of <15%. Lack of efficient treatment options contributes to the high mortality rate of EAC. To find new therapy against EAC we performed unbiased drug screening of an FDA-approved drug library and identified that the cardiac glycosides including Ouabain, Digoxin and Digitoxin efficiently inhibit the proliferation of EAC cell lines (OE33 and OE19) both in vitro and in vivo. RNA-Sequencing analysis combined with RNAi screening revealed that Ouabain suppresses the proliferation of EAC cells through downregulation of p38 MAP-Kinase 6 (MAP2K6, also known as MKK6). Consistently, shRNA-mediated knockdown of MKK6 reduced the proliferation of EAC cells and tumor growth. Further analysis demonstrated that MKK6 inhibition leads to the reduced levels of the transcription factor SOX9. In line with this finding, deletion of SOX9 with CRISPR/Cas9 resulted in decreased proliferation of EACs in 3D organoid culture and reduced tumor growth. Together these findings establish a druggable axis that can be harnessed for therapeutic gain against EAC.


Assuntos
Adenocarcinoma/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Neoplasias Esofágicas/tratamento farmacológico , MAP Quinase Quinase 6/antagonistas & inibidores , MAP Quinase Quinase 6/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Fatores de Transcrição SOX9/metabolismo , Adenocarcinoma/enzimologia , Adenocarcinoma/patologia , Animais , Linhagem Celular Tumoral , Digitoxina/farmacologia , Digitoxina/uso terapêutico , Digoxina/farmacologia , Digoxina/uso terapêutico , Neoplasias Esofágicas/enzimologia , Neoplasias Esofágicas/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , MAP Quinase Quinase 6/genética , Camundongos Endogâmicos NOD , Ouabaína/farmacologia , Ouabaína/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Fatores de Transcrição SOX9/genética , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Biomed Res Int ; 2017: 8050313, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29164150

RESUMO

The development of multitargeting drugs is an emerging trend in cancer research. To promote further development and clinical application of multitargeting drugs, this research was performed. MTT assay and flow cytometry of Annexin V/propidium iodide staining were used to confirm the proapoptotic efficacy of a novel combi-targeting molecule, JDF12, against DU145 prostate cancer (PCa) cells. Differentially expressed proteins between control and JDF12-treated cultures were revealed by isobaric tags for relative and absolute quantitation (iTRAQ), and part of them was confirmed by quantitative PCR. Differentially expressed proteins were further analyzed for function, pathway association, and protein-protein interactions using GO, KEGG, and STRING databases. A total of 119 differentially expressed proteins, 70 upregulated and 49 downregulated, were implicated in the anticancer effects of JDF12. Many of these proteins are involved in biosynthesis, response to stress, energy metabolism, and signal transduction. This study provides important information for understanding the anti-PCa mechanisms of JDF12, and well-designed combi-targeting drugs may possess stronger anticancer efficacy than single-targeting drugs and are thus promising candidates for clinical application.


Assuntos
Antineoplásicos/farmacologia , Receptores ErbB/genética , Terapia de Alvo Molecular , Neoplasias da Próstata/tratamento farmacológico , Linhagem Celular Tumoral , Receptores ErbB/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Proteínas de Neoplasias/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Mapas de Interação de Proteínas/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
19.
Nature ; 550(7677): 529-533, 2017 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-29019984

RESUMO

In several organ systems, the transitional zone between different types of epithelium is a hotspot for pre-neoplastic metaplasia and malignancy, but the cells of origin for these metaplastic epithelia and subsequent malignancies remain unknown. In the case of Barrett's oesophagus, intestinal metaplasia occurs at the gastro-oesophageal junction, where stratified squamous epithelium transitions into simple columnar cells. On the basis of a number of experimental models, several alternative cell types have been proposed as the source of this metaplasia but in all cases the evidence is inconclusive: no model completely mimics Barrett's oesophagus in terms of the presence of intestinal goblet cells. Here we describe a transitional columnar epithelium with distinct basal progenitor cells (p63+KRT5+KRT7+) at the squamous-columnar junction of the upper gastrointestinal tract in a mouse model. We use multiple models and lineage tracing strategies to show that this squamous-columnar junction basal cell population serves as a source of progenitors for the transitional epithelium. On ectopic expression of CDX2, these transitional basal progenitors differentiate into intestinal-like epithelium (including goblet cells) and thereby reproduce Barrett's metaplasia. A similar transitional columnar epithelium is present at the transitional zones of other mouse tissues (including the anorectal junction) as well as in the gastro-oesophageal junction in the human gut. Acid reflux-induced oesophagitis and the multilayered epithelium (believed to be a precursor of Barrett's oesophagus) are both characterized by the expansion of the transitional basal progenitor cells. Our findings reveal a previously unidentified transitional zone in the epithelium of the upper gastrointestinal tract and provide evidence that the p63+KRT5+KRT7+ basal cells in this zone are the cells of origin for multi-layered epithelium and Barrett's oesophagus.


Assuntos
Esôfago de Barrett/patologia , Linhagem da Célula , Células Epiteliais/patologia , Epitélio/patologia , Junção Esofagogástrica/patologia , Células-Tronco/patologia , Animais , Esôfago de Barrett/genética , Esôfago de Barrett/metabolismo , Fator de Transcrição CDX2/genética , Fator de Transcrição CDX2/metabolismo , Rastreamento de Células , Esofagite/metabolismo , Esofagite/patologia , Junção Esofagogástrica/metabolismo , Refluxo Gastroesofágico , Células Caliciformes/metabolismo , Células Caliciformes/patologia , Humanos , Queratina-5/metabolismo , Queratina-7/metabolismo , Metaplasia/metabolismo , Metaplasia/patologia , Camundongos , Fosfoproteínas/metabolismo , Células-Tronco/metabolismo , Transativadores/metabolismo
20.
Environ Sci Pollut Res Int ; 24(28): 22730-22740, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28861764

RESUMO

The extensive oil exploration has led to a series of environmental issues in the Niger Delta, Nigeria, over the years. Aside from oil spill, insufficient wastewater treatment of oil refineries and the discharged effluents become another potential source of pollution that has not received enough attention from the government and the public. Through reviewing the current oil refinery wastewater treatment processes and the discharge standards of wastewater effluents in Nigeria, we aimed to raise the awareness of the shortcomings of the current wastewater treatment technology and to discuss the consequences of insufficient treatment to the environment. This article further discussed the use of nanotechnology as a potential upgrade to the conventional treatment technologies as it has shown its capacity of removing persistent organic pollutants (POPs) or converting hazardous components to environmentally friendly derivatives. It should also prove beneficial to the key stakeholders involved in the exploration of crude oil in the region to consider optimization of oil refinery wastewater treatment processes through integration of emerging technologies.


Assuntos
Nanotecnologia/métodos , Indústria de Petróleo e Gás , Rios/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Nigéria , Petróleo/análise , Poluição por Petróleo/análise
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