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1.
Biochem Pharmacol ; 220: 115972, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38072164

RESUMO

Photorhabdus luminescens is a gram-negative bioluminescent bacterium known as an intestinal bacterium that coexists in the digestive tract of insect-pathogenic nematodes. As part of our ongoing exploration to identify bioactive compounds from diverse natural resources, the chemical analysis of the cultures of P. luminescens KACC 12254 via LC/MS and TLC-based analyses enabled the isolation and identification of a major fluorescent compound. Its chemical structure was elucidated as 1,8-dihydroxy-3-methoxyanthraquinone (DMA) using HR-ESI-MS and NMR analysis. In this study, we conducted comprehensive investigations utilizing human colorectal cancer HCT116 cells, human umbilical cord vascular endothelial cells (HUVECs), and zebrafish embryos to assess the potential benefits of DMA in suppressing tumor angiogenesis. Our results convincingly demonstrate that DMA effectively suppresses the stability of hypoxia-inducible factor-1α (HIF-1α) protein and its target genes without inducing any cytotoxic effects. Furthermore, DMA demonstrates the ability to inhibit HIF-1α transcriptional activation and mitigate the production of reactive oxygen species (ROS). In our in vitro experiments, DMA exhibits notable inhibitory effects on VEGF-mediated tube formation, migration, and invasion in HUVECs. Additionally, in vivo investigations using zebrafish embryos confirm the antiangiogenic properties of DMA. Notably, DMA does not exhibit any adverse developmental or cardiotoxic effects in the in vivo setting. Moreover, we observe DMA's capability to restrain tumor growth through the downregulation of PI3K/AKT and c-RAF/ERK pathway. Collectively, these compelling findings underscore DMA's potential as a promising therapeutic candidate for targeted intervention against HIF-1α and angiogenesis in cancer treatment.


Assuntos
Transdução de Sinais , Peixe-Zebra , Animais , Humanos , Antraquinonas/farmacologia , Linhagem Celular Tumoral , Regulação para Baixo , Células Endoteliais/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo
2.
J Hazard Mater ; 464: 132932, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-37988864

RESUMO

Chronic obstructive pulmonary disease (COPD) is a group of illnesses associated with unresolved inflammation in response to toxic environmental stimuli. Persistent exposure to PM is a major risk factor for COPD, but the underlying mechanism remains unclear. Using our established mouse model of PM-induced COPD, we find that repeated PM exposure provokes macrophage-centered chronic inflammation and COPD development. Mechanistically, chronic PM exposure induces transcriptional downregulation of HAAO, KMO, KYNU, and QPRT in macrophages, which are the enzymes of de novo NAD+ synthesis pathway (kynurenine pathway; KP), via elevated chromatin binding of the CCCTC-binding factor (CTCF) near the transcriptional regulatory regions of the enzymes. Subsequent reduction of NAD+ and SIRT1 function increases histone acetylation, resulting in elevated expression of pro-inflammatory genes in PM-exposed macrophages. Activation of SIRT1 by nutraceutical resveratrol mitigated PM-induced chronic inflammation and COPD development. In agreement, increased levels of histone acetylation and decreased expression of KP enzymes were observed in pulmonary macrophages of COPD patients. We newly provide an evidence that dysregulated NAD+ metabolism and consecutive SIRT1 deficiency significantly contribute to the pathological activation of macrophages during PM-mediated COPD pathogenesis. Additionally, targeting PM-induced intertwined metabolic and epigenetic reprogramming in macrophages is an effective strategy for COPD treatment.


Assuntos
Material Particulado , Doença Pulmonar Obstrutiva Crônica , Animais , Camundongos , Humanos , Material Particulado/toxicidade , Material Particulado/metabolismo , Sirtuína 1/genética , Sirtuína 1/metabolismo , Sirtuína 1/farmacologia , Histonas/metabolismo , NAD/metabolismo , Doença Pulmonar Obstrutiva Crônica/induzido quimicamente , Doença Pulmonar Obstrutiva Crônica/genética , Macrófagos , Inflamação/metabolismo , Epigênese Genética
3.
Biomed Pharmacother ; 165: 115037, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37393867

RESUMO

Panax ginseng, also known as Korean ginseng, is a traditional remedy widely used in Asian countries. Its major active compounds are ginsenosides, specifically triterpenoid saponins. Among them, one notable ginsenoside called Re has shown various biological effects, including anti-cancer and anti-inflammatory properties. However, the potential beneficial effects of Re on melanogenesis and skin cancer remain poorly understood. To investigate this, we conducted a comprehensive study using biochemical assays, cell-based models, a zebrafish pigment formation model, and a tumor xenograft model. Our results revealed that Re effectively inhibited melanin biosynthesis in a dose-dependent manner by competitively inhibiting the activity of tyrosinase, an enzyme involved in melanin production. Moreover, Re significantly reduced the mRNA expression levels of microphthalmia-associated transcription factor (MITF), a key regulator of melanin biosynthesis and melanoma growth. Furthermore, Re decreased the protein expression of MITF and its target genes, including tyrosinase, TRP-1, and TRP-2, through a partially ubiquitin-dependent proteasomal degradation mechanism, mediated by the AKT and ERK signaling pathways. These findings indicate that Re exerts its hypopigmentary effects by directly inhibiting tyrosinase activity and suppressing its expression via MITF. Additionally, Re demonstrated inhibitory effects on skin melanoma growth and induced tumor vascular normalization in our in vivo experiments. This study represents the first evidence of Re-mediated inhibition of melanogenesis and skin melanoma, shedding light on the underlying mechanisms. These promising preclinical findings warrant further investigation to determine the suitability of Re as a natural agent for treating hyperpigmentation disorders and skin cancer.


Assuntos
Ginsenosídeos , Melanoma Experimental , Melanoma , Neoplasias Cutâneas , Animais , Humanos , Ginsenosídeos/farmacologia , Monofenol Mono-Oxigenase/metabolismo , Melaninas , Fator de Transcrição Associado à Microftalmia/genética , Fator de Transcrição Associado à Microftalmia/metabolismo , Peixe-Zebra/metabolismo , Linhagem Celular Tumoral , Melanoma/patologia , Neoplasias Cutâneas/patologia , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/metabolismo
4.
Eur J Med Chem ; 256: 115421, 2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37163949

RESUMO

Scaffold hopping of N-benzyl-3,4,5-trimethoxyaniline afforded 5,6,7-trimethoxyflavan derivatives that were efficiently synthesized in four linear steps. As lung cancer is the most lethal cancer, twenty-three synthesized compounds were evaluated against a panel of lung cancer cells. Amongst, compounds 8q and 8e showed interesting activity. Hence, compounds 8q and 8e were evaluated against panels of diverse cancers. Compounds 8q and 8e showed broad spectrum anticancer activity. However, compound 8q was more effective and, hence, was advanced for potency evaluation and characterization. Compound 8q showed comparable potencies to gefitinib, and oxaliplatin against lung and colorectal cancers, respectively, and superior potencies to temozolomide, dacarbazine, cisplatin, enzalutamide, methotrexate, imatinib against brain, skin, ovary, prostate, breast, and blood cancers, respectively. Compound 8q increased cleaved PARP, caspase 3, and 7 inducing apoptosis. In addition, it inhibited cyclins A, B1, H and cdc25c, and increased p53 triggering cell cycle arrest in G2/M phase. Moreover, it decreased YAP and increased LATS1 and p-mob1/mob1 activating hippo signaling. Furthermore, it decreased p-PI3K/PI3k, p-mTOR/mTOR and p-P70S6K/P70S6K inhibiting PI3k pathway. Together, these findings present compound 8q as a potential anticancer lead compound for further development of potential agents.


Assuntos
Antineoplásicos , Neoplasias Pulmonares , Masculino , Feminino , Humanos , Via de Sinalização Hippo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Apoptose , Serina-Treonina Quinases TOR/metabolismo , Proliferação de Células
6.
Exp Mol Med ; 55(6): 1131-1144, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37258578

RESUMO

The renin-angiotensin (RA) system has been implicated in lung tumorigenesis without detailed mechanistic elucidation. Here, we demonstrate that exposure to the representative tobacco-specific carcinogen nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) promotes lung tumorigenesis through deregulation of the pulmonary RA system. Mechanistically, NNK binding to the nicotinic acetylcholine receptor (nAChR) induces Src-mediated signal transducer and activator of transcription 3 (STAT3) activation, resulting in transcriptional upregulation of angiotensinogen (AGT) and subsequent induction of the angiotensin II (AngII) receptor type 1 (AGTR1) signaling pathway. In parallel, NNK concurrently increases insulin-like growth factor 2 (IGF2) production and activation of IGF-1R/insulin receptor (IR) signaling via a two-step pathway involving transcriptional upregulation of IGF2 through STAT3 activation and enhanced secretion from intracellular storage through AngII/AGTR1/PLC-intervened calcium release. NNK-mediated crosstalk between IGF-1R/IR and AGTR1 signaling promoted tumorigenic activity in lung epithelial and stromal cells. Lung tumorigenesis caused by NNK exposure or alveolar type 2 cell-specific Src activation was suppressed by heterozygous Agt knockout or clinically available inhibitors of the nAChR/Src or AngII/AGTR1 pathways. These results demonstrate that NNK-induced stimulation of the lung RA system leads to IGF2-mediated IGF-1R/IR signaling activation in lung epithelial and stromal cells, resulting in lung tumorigenesis in smokers.


Assuntos
Neoplasias Pulmonares , Nitrosaminas , Receptores Nicotínicos , Carcinógenos/toxicidade , Nitrosaminas/toxicidade , Nitrosaminas/metabolismo , Receptores Nicotínicos/metabolismo , Sistema Renina-Angiotensina , Fator de Transcrição STAT3/metabolismo , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Transdução de Sinais , Pulmão/metabolismo , Carcinogênese
7.
J Nat Prod ; 86(4): 850-859, 2023 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-36921254

RESUMO

Antibiotic resistance is one of the world's most urgent public health problems, and novel antibiotics to kill drug-resistant bacteria are needed. Natural product-derived small molecules have been the major source of new antibiotics. Here we describe a family of antibacterial metabolites isolated from a probiotic bacterium, Bacillus licheniformis. A cross-streaking assay followed by activity-guided isolation yielded a novel antibacterial metabolite, bacillimidazole G, which possesses a rare imidazolium ring in the structure, showing MIC values of 0.7-2.6 µg/mL against human pathogenic Gram-positive and Gram-negative bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and a lipopolysaccharide (LPS)-lacking Acinetobacter baumannii ΔlpxC. Bacillimidazole G also lowered MICs of colistin, a Gram-negative antibiotic, up to 8-fold against wild-type Escherichia coli MG1655 and A. baumannii. We propose a biosynthetic pathway to the characterized metabolites based on precursor-feeding studies, a chemical biological approach, biomimetic total synthesis, and a biosynthetic gene knockout method.


Assuntos
Bacillus licheniformis , Staphylococcus aureus Resistente à Meticilina , Humanos , Antibacterianos/farmacologia , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Testes de Sensibilidade Microbiana
8.
J Exp Clin Cancer Res ; 41(1): 133, 2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35395804

RESUMO

BACKGROUND: Cancer stem-like cells (CSCs) play a pivotal role in lung tumor formation and progression. Nerve injury-induced protein 1 (Ninjurin1, Ninj1) has been implicated in lung cancer; however, the pathological role of Ninj1 in the context of lung tumorigenesis remains largely unknown. METHODS: The role of Ninj1 in the survival of non-small cell lung cancer (NSCLC) CSCs within microenvironments exhibiting hazardous conditions was assessed by utilizing patient tissues and transgenic mouse models where Ninj1 repression and oncogenic KrasG12D/+ or carcinogen-induced genetic changes were induced in putative pulmonary stem cells (SCs). Additionally, NSCLC cell lines and primary cultures of patient-derived tumors, particularly Ninj1high and Ninj1low subpopulations and those with gain- or loss-of-Ninj1 expression, and also publicly available data were all used to assess the role of Ninj1 in lung tumorigenesis. RESULTS: Ninj1 expression is elevated in various human NSCLC cell lines and tumors, and elevated expression of this protein can serve as a biomarker for poor prognosis in patients with NSCLC. Elevated Ninj1 expression in pulmonary SCs with oncogenic changes promotes lung tumor growth in mice. Ninj1high subpopulations within NSCLC cell lines, patient-derived tumors, and NSCLC cells with gain-of-Ninj1 expression exhibited CSC-associated phenotypes and significantly enhanced survival capacities in vitro and in vivo in the presence of various cell death inducers. Mechanistically, Ninj1 forms an assembly with lipoprotein receptor-related protein 6 (LRP6) through its extracellular N-terminal domain and recruits Frizzled2 (FZD2) and various downstream signaling mediators, ultimately resulting in transcriptional upregulation of target genes of the LRP6/ß-catenin signaling pathway. CONCLUSIONS: Ninj1 may act as a driver of lung tumor formation and progression by protecting NSCLC CSCs from hostile microenvironments through ligand-independent activation of LRP6/ß-catenin signaling.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Moléculas de Adesão Celular Neuronais , Neoplasias Pulmonares , Fatores de Crescimento Neural , Via de Sinalização Wnt , Animais , Carcinogênese/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Moléculas de Adesão Celular Neuronais/genética , Linhagem Celular Tumoral , Receptores Frizzled , Humanos , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Neoplasias Pulmonares/patologia , Camundongos , Fatores de Crescimento Neural/genética , Microambiente Tumoral , beta Catenina/metabolismo
9.
Cell Death Differ ; 29(6): 1199-1210, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34974535

RESUMO

Ninjurin1 (Ninj1), an adhesion molecule, regulates macrophage function in hyaloid regression, multiple sclerosis, and atherosclerosis. However, its biological relevance and the mechanism underlying its function in vascular network integrity have not been studied. In this study, we investigated the role of Ninj1 in physiological (postnatal vessel formation) and pathological (endotoxin-mediated inflammation and diabetes) conditions and developed a strategy to regulate Ninj1 using specific micro (mi)RNAs under pathological conditions. Ninj1-deficient mice exhibited decreased hyaloid regression, tip cell formation, retinal vascularized area, recruitment of macrophages, and endothelial apoptosis during postnatal development, resulting in delayed formation of the vascular network. Five putative miRNAs targeting Ninj1 were selected using the miRanda algorithm and comparison of expression patterns. Among them, miR-125a-5p showed a profound inhibitory effect on Ninj1 expression, and miR-125a-5p mimic suppressed the cell-to-cell and cell-to-matrix adhesion of macrophages and expression of pro-inflammatory factors mediated by Ninj1. Furthermore, miR-125a-5p mimic inhibited the recruitment of macrophages into inflamed retinas in endotoxin-induced inflammation and streptozotocin-induced diabetes in vivo. In particular, miR-125a-5p mimic significantly attenuated vascular leakage in diabetic retinopathy. Taken together, these findings suggest that Ninj1 plays a pivotal role in macrophage-mediated vascular integrity and that miR-125a-5p acts as a novel regulator of Ninj1 in the management of inflammatory diseases and diabetic retinopathy.


Assuntos
Moléculas de Adesão Celular Neuronais , Retinopatia Diabética , MicroRNAs , Fatores de Crescimento Neural , Animais , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Retinopatia Diabética/genética , Retinopatia Diabética/metabolismo , Endotoxinas/metabolismo , Inflamação/genética , Inflamação/metabolismo , Macrófagos/metabolismo , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Fatores de Crescimento Neural/genética , Fatores de Crescimento Neural/metabolismo
10.
Biomed Pharmacother ; 145: 112474, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34864308

RESUMO

Cristacarpin is a novel prenylated pterocarpan that reportedly exhibits broad anti-cancer activity by enhancing endoplasmic reticulum stress. However, whether and how cristacarpin affects in-flammatory processes remain largely unknown. In the present study, the anti-inflammatory effect of cristacarpin on lipopolysaccharide (LPS)-induced inflammation was investigated using zebrafish embryos, RAW 264.7 macrophages, and mouse uveitis models. In the non-toxic concentration range (from 20 to 100 µM), cristacarpin suppressed pro-inflammatory mediators such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, while stimulating anti-inflammatory mediators such as IL-4 and IL-10 in LPS-stimulated RAW 264.7 cells and uveitis mouse models. Cristacarpin decreased cell adhesion of macrophages through downregulation of the expression of Ninjurin1 and matrix metalloproteinases. Furthermore, cristacarpin reduced macrophage migration in zebrafish embryos in vivo. Cristacarpin also increased cytosolic levels of inhibitor of nuclear factor-κB and suppressed the nuclear translocation of nuclear factor κ-light-chain-enhancer of activated B cells. Collectively, our results suggest that cristacarpin is a potential therapeutic candidate for developing ocular anti-inflammatory drugs.


Assuntos
Mediadores da Inflamação/metabolismo , Macrófagos/imunologia , Pterocarpanos/farmacologia , Uveíte , Animais , Anti-Inflamatórios/farmacologia , Moléculas de Adesão Celular Neuronais/metabolismo , Modelos Animais de Doenças , Interleucinas/metabolismo , Camundongos , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , Fatores de Crescimento Neural/metabolismo , Extratos Vegetais/farmacologia , Células RAW 264.7 , Fator de Necrose Tumoral alfa/metabolismo , Uveíte/tratamento farmacológico , Uveíte/metabolismo , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
11.
J Sci Food Agric ; 102(3): 1255-1262, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34358346

RESUMO

BACKGROUND: Artemisia capillaris is among the most abundantly used traditional medicines, utilized in East Asia to treat diverse illnesses, including gastrointestinal tract diseases. We previously reported that an aqueous extract of A. capillaris (AEAC) inhibited gastric inflammation induced by HCl/ethanol via reactive oxygen species scavenging and NF-κB downregulation. To date, the pharmacological potential of AEAC for promoting mucosal integrity has not been studied. RESULTS: Here, we report that a single treatment with AEAC increased mucus production, and repeated administration of AEAC abolished HCl/ethanol-induced mucosal injury in vivo. Single- and multiple-dose AEAC treatments measurably increased the expression of mucosal stabilizing factors in vivo, including mucin (MUC) 5 AC, MUC6, and trefoil factor (TFF) 1 and TFF2 (but not TFF3). AEAC also induced mucosal stabilizing factors in both SNU-601 cells and RGM cells through phosphorylation of extracellular signal-regulated kinases. CONCLUSION: Taken together, our results suggest that AEAC protects against HCl/ethanol-induced gastritis by upregulating MUCs and TFFs and stabilizing the mucosal epithelium. © 2021 Society of Chemical Industry.


Assuntos
Artemisia/química , Medicamentos de Ervas Chinesas/farmacologia , Mucosa Gástrica/efeitos dos fármacos , Gastropatias/tratamento farmacológico , Animais , Mucosa Gástrica/imunologia , Mucosa Gástrica/lesões , Humanos , Masculino , Mucinas/genética , Mucinas/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Folhas de Planta/química , Ratos , Ratos Sprague-Dawley , Gastropatias/genética , Gastropatias/imunologia , Fator Trefoil-1/genética , Fator Trefoil-1/imunologia
12.
Artigo em Inglês | MEDLINE | ID: mdl-34500089

RESUMO

Mammalian claudin-5 (cldn5), a zebrafish cldn5a homolog, is essential to blood-brain barrier (BBB) integrity. Previously, the existence of an endothelial tight junction-based BBB with cldn5a expression in the cerebral microvessels was reported in zebrafish. However, the role of cldn5a in the cerebral microvessels of developing zebrafish has not been elucidated. Here, we further investigated the functional integrity of cldn5a in developing zebrafish by injecting cldn5a morpholinos. At 7 days post-fertilization, cldn5a immunoreactivity was detected on the brain surface, ventricular ependyma, and cerebral mircovessels but disappeared following cldna5a knockdown. Cldn5a morphants showed size-selective leakage of tracers through the BBB and downregulated expression of glucose transporter 1 (glut1) in the cerebral microvessels. In addition, leakiness in the blood-cerebrospinal fluid barrier was observed, implying the overall abnormal development of blood-neural barriers. The results of our study suggest that cldn5a is required for building and maintaining the blood-neural barrier during zebrafish development.


Assuntos
Barreira Hematoencefálica/metabolismo , Claudina-5/antagonistas & inibidores , Proteínas de Peixe-Zebra/antagonistas & inibidores , Peixe-Zebra/fisiologia , Animais , Transporte Biológico , Barreira Hematoencefálica/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Ventrículos Cerebrais/metabolismo , Ventrículos Cerebrais/patologia , Claudina-5/genética , Claudina-5/metabolismo , Morfolinos/farmacologia , Junções Íntimas/metabolismo , Junções Íntimas/patologia , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
13.
Antioxidants (Basel) ; 10(5)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064830

RESUMO

This study was designed to determine whether α-humulene, a major constituent in many plants used in fragrances, has a protective role against gastric injury in vivo and in vitro. A rat model of hydrochloric acid (HCl)/ethanol-induced gastritis and human mast cells (HMC-1) were used to investigate the mucosal protective effect of α-humulene. α-Humulene significantly inhibited gastric lesions in HCl/ethanol-induced acute gastritis and decreased gastric acid secretion pyloric ligation-induced gastric ulcers in vivo. In addition, α-humulene reduced the amount of reactive oxygen species and malondialdehyde through upregulation of prostaglandin E2 (PGE2) and superoxide dismutase (SOD). In HMC-1 cells, α-humulene decreased intracellular calcium and increased intracellular cyclic adenosine monophosphate (cAMP) levels, resulting in low histamine levels. α-Humulene also reduced the expression levels of cytokine genes such as interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF) by downregulating nuclear factor-κB (NF-κB) nuclear translocation. Finally, α-humulene upregulated the expression levels of mucin 5AC (Muc5ac), Muc6, trefoil factor 1 (Tff1), trefoil factor 2 (Tff2), and polymeric immunoglobulin receptor (pigr). α-Humulene may attenuate HCl/ethanol-induced gastritis by inhibiting histamine release and NF-κB activation and stimulating antioxidants and mucosal protective factors, particularly Muc5ac and Muc6. Therefore, these data suggest that α-humulene is a potential drug candidate for the treatment of stress-induced or alcoholic gastritis.

14.
J Pineal Res ; 71(1): e12739, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33955074

RESUMO

Hypoxia-inducible factor-1 (HIF-1) plays an important role in cellular responses to hypoxia, including the transcriptional activation of several genes involved in tumor angiogenesis. Melatonin, also known as N-acetyl-5-methopxytryptamine, is produced naturally by the pineal gland and has anti-angiogenic effects in cancer through its ability to modulate HIF-1α activity. However, the use of melatonin as a therapeutic is limited by its low oral bioavailability and short half-life. Here, we synthesized melatonin-like molecules with enhanced HIF-1α targeting activity and less toxicity and investigated their effects on tumor growth and angiogenesis, as well as the underlying molecular mechanisms. Among melatonin derivatives, N-butyryl-5-methoxytryptamine (NB-5-MT) showed the most potent HIF-1α targeting activity. This molecule was able to (a) reduce the expression of HIF-1α at the protein level, (b) reduce the transcription of HIF-1α target genes, (c) reduce reactive oxygen species (ROS) generation, (d) decrease angiogenesis in vitro and in vivo, and (e) suppress tumor size and metastasis. In addition, NB-5-MT showed improved anti-angiogenic activity compared with melatonin due to its enhanced cellular uptake. NB-5-MT is thus a promising lead for the future development of anticancer compounds with HIF-1α targeting activity. Given that HIF-1α is overexpressed in the majority of human cancers, the melatonin derivative NB-5-MT could represent a novel potent therapeutic agent for cancer.


Assuntos
Inibidores da Angiogênese/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Melatonina/análogos & derivados , Animais , Células Cultivadas , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Ensaios Antitumorais Modelo de Xenoenxerto , Peixe-Zebra
15.
Sensors (Basel) ; 21(6)2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33804591

RESUMO

Semantic segmentation, which refers to pixel-wise classification of an image, is a fundamental topic in computer vision owing to its growing importance in the robot vision and autonomous driving sectors. It provides rich information about objects in the scene such as object boundary, category, and location. Recent methods for semantic segmentation often employ an encoder-decoder structure using deep convolutional neural networks. The encoder part extracts features of the image using several filters and pooling operations, whereas the decoder part gradually recovers the low-resolution feature maps of the encoder into a full input resolution feature map for pixel-wise prediction. However, the encoder-decoder variants for semantic segmentation suffer from severe spatial information loss, caused by pooling operations or stepwise convolutions, and does not consider the context in the scene. In this paper, we propose a novel dense upsampling convolution method based on a guided filter to effectively preserve the spatial information of the image in the network. We further propose a novel local context convolution method that not only covers larger-scale objects in the scene but covers them densely for precise object boundary delineation. Theoretical analyses and experimental results on several benchmark datasets verify the effectiveness of our method. Qualitatively, our approach delineates object boundaries at a level of accuracy that is beyond the current excellent methods. Quantitatively, we report a new record of 82.86% and 81.62% of pixel accuracy on ADE20K and Pascal-Context benchmark datasets, respectively. In comparison with the state-of-the-art methods, the proposed method offers promising improvements.

16.
Biomedicines ; 9(4)2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33924583

RESUMO

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1ß (IL-1ß), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.

17.
J Clin Invest ; 131(1)2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33393490

RESUMO

Slow-cycling/dormant cancer cells (SCCs) have pivotal roles in driving cancer relapse and drug resistance. A mechanistic explanation for cancer cell dormancy and therapeutic strategies targeting SCCs are necessary to improve patient prognosis, but are limited because of technical challenges to obtaining SCCs. Here, by applying proliferation-sensitive dyes and chemotherapeutics to non-small cell lung cancer (NSCLC) cell lines and patient-derived xenografts, we identified a distinct SCC subpopulation that resembled SCCs in patient tumors. These SCCs displayed major dormancy-like phenotypes and high survival capacity under hostile microenvironments through transcriptional upregulation of regulator of G protein signaling 2 (RGS2). Database analysis revealed RGS2 as a biomarker of retarded proliferation and poor prognosis in NSCLC. We showed that RGS2 caused prolonged translational arrest in SCCs through persistent eukaryotic initiation factor 2 (eIF2α) phosphorylation via proteasome-mediated degradation of activating transcription factor 4 (ATF4). Translational activation through RGS2 antagonism or the use of phosphodiesterase 5 inhibitors, including sildenafil (Viagra), promoted ER stress-induced apoptosis in SCCs in vitro and in vivo under stressed conditions, such as those induced by chemotherapy. Our results suggest that a low-dose chemotherapy and translation-instigating pharmacological intervention in combination is an effective strategy to prevent tumor progression in NSCLC patients after rigorous chemotherapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de Neoplasias/metabolismo , Biossíntese de Proteínas , Proteínas RGS/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas RGS/genética , Recidiva , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Genes Genomics ; 43(4): 313-321, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33094376

RESUMO

BACKGROUND: Under hypoxia, mouse embryonic stem cells (mESCs) lose the ability to self-renew and begin to differentiate through down-regulation of LIFR-STAT3 pathway via hypoxia-inducible factor-1α (HIF-1α). However, it remains largely unknown what kinds of factors are involved in hypoxia-induced differentiation of mESCs. PURPOSE: This study aims to identify the differentially expressed genes (DEGs) in early differentiation of mESCs under hypoxia. METHODS: Here we utilized a Genefishing techniqueTM to discover the new DEGs during hypoxia-induced early differentiation in CCE mESCs. Next, we investigated the role of DEGs using morphological observation, alkaline phosphatase (ALP) assay, STAT3 activation analysis, and biomarkers analysis for stemness. RESULTS: We detected 19 DEGs under hypoxia and performed cloning with sequencing in six genes. We confirmed the expression patterns of five DEGs including H2afz and GOT1 by realtime PCR assay. Among them, H2afz was significantly decreased under hypoxia, depending on HIF-1α. H2afz-overexpressing CCE mESCs maintained their ALP activity and stem cell markers (Nanog and Rex1), even in hypoxic condition. On the other hand, the early differentiation markers such as FGF5 and STAT5a, which had been increased in hypoxic conditions, were reduced by H2afz overexpression. CONCLUSION: We discovered that H2afz could be a new target gene that functions in hypoxia-induced differentiation in mESCs and have revealed that it is involved in maintaining the pluripotency of mESCs in the early stages of differentiation. These findings will provide insights into mechanisms of hypoxia-mediated differentiation of mESCs during early development.


Assuntos
Células-Tronco Embrionárias Murinas/metabolismo , Animais , Diferenciação Celular , Hipóxia Celular , Linhagem Celular , Expressão Gênica , Histonas/genética , Histonas/metabolismo , Camundongos , Células-Tronco Embrionárias Murinas/citologia
19.
Cancers (Basel) ; 12(7)2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32630838

RESUMO

Slow-cycling cancer cells (SCCs) with a quiescence-like phenotype are believed to perpetrate cancer relapse and progression. However, the mechanisms that mediate SCC-derived tumor recurrence are poorly understood. Here, we investigated the mechanisms underlying cancer recurrence after chemotherapy, focusing on the interplay between SCCs and the tumor microenvironment. We established a preclinical model of SCCs by exposing non-small-cell lung cancer (NSCLC) cells to either the proliferation-dependent dye carboxyfluorescein diacetate succinimidyl ester (CFSE) or chemotherapeutic drugs. An RNA sequencing analysis revealed that the established SCCs exhibited the upregulation of a group of genes, especially epidermal growth factor (EGF). Increases in the number of vascular endothelial growth factor receptor (VEGFR)-positive vascular endothelial cells and epidermal growth factor receptor (EGFR) activation were found in NSCLC cell line- and patient-derived xenograft tumors that progressed upon chemotherapy. EGFR tyrosine kinase inhibitors effectively suppressed the migration and tube formation of vascular endothelial cells. Furthermore, activating transcription factor 6 (ATF6) induced the upregulation of EGF, and its antagonism effectively suppressed these SCC-mediated events and inhibited tumor recurrence after chemotherapy. These results suggest that the ATF6-EGF signaling axis in SCCs functions to trigger the angiogenesis switch in residual tumors after chemotherapy and is thus a driving force for the switch from SCCs to actively cycling cancer cells, leading to tumor recurrence.

20.
Sensors (Basel) ; 20(14)2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32698504

RESUMO

Point cloud registration is a key problem in computer vision applications and involves finding a rigid transform from a point cloud into another such that they align together. The iterative closest point (ICP) method is a simple and effective solution that converges to a local optimum. However, despite the fact that point cloud registration or alignment is addressed in learning-based methods, such as PointNetLK, they do not offer good generalizability for point clouds. In this stud, we proposed a learning-based approach that addressed existing problems, such as finding local optima for ICP and achieving minimum generalizability. The proposed model consisted of three main parts: an encoding network, an auxiliary module that weighed the contribution of each input point cloud, and feature alignment to achieve the final transform. The proposed architecture offered greater generalization among the categories. Experiments were performed on ModelNet40 with different configurations and the results indicated that the proposed approach significantly outperformed the state-of-the-art point cloud alignment methods.

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