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1.
Phytomedicine ; 118: 154970, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37516056

RESUMO

BACKGROUND: Oolonghomobisflavans are unique polyphenols found in oolong teas. Oolonghomobisflavan B (OHBFB), a dimer of (-)-epigallocatechin-3-O-gallate (EGCG), is an active compound found in green tea. PURPOSE: OHBFB has been reported to exert an inhibitory effect on lipase enzyme activity. However, little is known regarding its intercellular signaling induction effect. Further, there are no reports describing the anti-cancer effects of OHBFB. METHODS: The effect of OFBFB on B16 melanoma cells was evaluated by cell counting, and its mechanisms were determined by western blot analysis with or without protein phosphatase 2A (PP2A) inhibitor treatment. Intracellular cyclic adenosine monophosphate (cAMP) levels were evaluated by time-resolved fluorescence resonance energy transfer analysis. Quartz crystal microbalance (QCM) analysis was performed to assess the binding of OHBFB to 67LR. RESULTS: Cell growth assay and western blot analyses showed that OHBFB inhibited melanoma cell growth, followed by myosin phosphatase target subunit 1 (MYPT1) and myosin regulatory light chain (MRLC) dephosphorylation via protein phosphatase 2A (PP2A)-dependent mechanisms. These effects are mediated by intracellular cAMP- and protein kinase A (PKA) A-dependent mechanisms. QCM analysis identified the 67-kDa laminin receptor (67LR) as an OHBFB receptor with a Kd of 3.7 µM. We also demonstrated for the first time that OHBFB intake suppresses tumor growth in vivo. CONCLUSIONS: Taken together, these results indicate that the cAMP/PKA/PP2A/MYPT1/MRLC pathway is a key mediator of melanoma cell growth inhibition following OHBFB binding to 67LR and that OHBFB suppresses tumor growth in vivo.


Assuntos
Catequina , Melanoma Experimental , Animais , Humanos , Proteína Fosfatase 2/metabolismo , Polifenóis/farmacologia , Catequina/farmacologia , Ciclo Celular , Melanoma Experimental/tratamento farmacológico , Receptores de Laminina/química , Receptores de Laminina/metabolismo
2.
Cell Mol Life Sci ; 80(8): 207, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37452879

RESUMO

The cellular prion protein (PrPC) is well-known for its involvement, under its pathogenic protease-resistant form (PrPSc), in a group of neurodegenerative diseases, known as prion diseases. PrPC is expressed in nervous system, as well as in other peripheral organs, and has been found overexpressed in several types of solid tumors. Notwithstanding, studies in recent years have disclosed an emerging role for PrPC in various cancer associated processes. PrPC has high binding affinity for 37/67 kDa laminin receptor (RPSA), a molecule that acts as a key player in tumorigenesis, affecting cell growth, adhesion, migration, invasion and cell death processes. Recently, we have characterized at cellular level, small molecules able to antagonize the direct PrPC binding to RPSA and their intracellular trafficking. These findings are very crucial considering that the main function of RPSA is to modulate key events in the metastasis cascade. Elucidation of the role played by PrPC/RPSA interaction in regulating tumor development, progression and response to treatment, represents a very promising challenge to gain pathogenetic information and discover novel specific biomarkers and/or therapeutic targets to be exploited in clinical settings. This review attempts to convey a detailed description of the complexity surrounding these multifaceted proteins from the perspective of cancer hallmarks, but with a specific focus on the role of their interaction in the control of proliferation, migration and invasion, genome instability and mutation, as well as resistance to cell death controlled by autophagic pathway.


Assuntos
Neoplasias , Proteínas PrPC , Doenças Priônicas , Príons , Humanos , Proteínas Priônicas/genética , Proteínas Priônicas/metabolismo , Doenças Priônicas/metabolismo , Receptores de Laminina/genética , Receptores de Laminina/metabolismo , Neoplasias/genética , Biologia , Proteínas PrPC/genética , Proteínas PrPC/metabolismo
3.
Biochem Biophys Res Commun ; 671: 116-123, 2023 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-37300941

RESUMO

Quercetin, a dietary flavonoid, has been shown to protect against various neurodegenerative diseases with mechanisms largely unknown. After oral administration, quercetin is rapidly conjugated, and the aglycone is not detectable in the plasma and brain. However, its glucuronide and sulfate conjugates are present only at low nanomolar concentrations in the brain. Since quercetin and its conjugates have limited antioxidant capability at low nanomolar concentrations, it is crucial to determine whether they induce neuroprotection by binding to high-affinity receptors. Previously we found that (-)-epigallocatechin-3-gallate (EGCG), a polyphenol from green tea, induces neuroprotection by binding to the 67-kDa laminin receptor (67LR). Therefore, in this study, we determined whether quercetin and its conjugates bind 67LR to induce neuroprotection and compared their ability with EGCG. Based on the quenching of intrinsic tryptophan fluorescence of peptide G (residues 161-180 in 67LR), we found quercetin, quercetin-3-O-glucuronide, and quercetin-3-O-sulfate bind to this peptide with a high affinity comparable to EGCG. Molecular docking using the crystal structure of 37-kDa laminin receptor precursor supported the high-affinity binding of all these ligands to the site corresponding to peptide G. A pretreatment with quercetin (1-1000 nM) did not effectively protect Neuroscreen-1 cells from death induced by serum starvation. Contrarily, a pretreatment with low concentrations (1-10 nM) of quercetin conjugates better protected these cells than quercetin and EGCG. The 67LR-blocking antibody substantially prevented neuroprotection by all these agents, suggesting the role of 67LR in this process. Collectively, these studies reveal that quercetin induces neuroprotection primarily through its conjugates via high affinity binding to 67LR.


Assuntos
Catequina , Flavonoides , Flavonoides/farmacologia , Quercetina/farmacologia , Glucuronídeos/farmacologia , Sulfatos , Simulação de Acoplamento Molecular , Polifenóis/farmacologia , Receptores de Laminina/metabolismo , Catequina/farmacologia , Moléculas de Adesão Celular , Morte Celular
4.
Int J Mol Sci ; 24(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36769107

RESUMO

Maintaining the integrity and protecting the stability of tight junctions in endothelial cells is a potential therapeutic strategy against myocardial ischaemia. Laminin receptors (67LR) are highly expressed on endothelial cell membranes and are associated with endothelial barrier function. Herein, we sought to demonstrate the direct effects of pigment epithelial-derived factor (PEDF) on tight junctions between endothelial cells via 67LR during acute myocardial infarction (AMI) and elucidate its underlying mechanisms. We detected that PEDF directly increased the level of the tight junction protein zonula occludens protein 1 (ZO-1) after overexpression in vitro and in vivo using Western blotting. Evans Blue/TTC staining showed that PEDF significantly reduced the size of the infarcted myocardium. Immunofluorescence and the transwell cellular experiments suggested that PEDF significantly upregulated PI3K-AKT permeability and the distribution of ZO-1 between endothelial cells under OGD conditions. Interestingly, PEDF significantly upregulated the phosphorylation levels of PI3K-AKT-mTOR under oxygen and glucose deprivation conditions but had no significant effects on the total protein expression. The protective effect of PEDF on ZO-1 was significantly inhibited following the inhibition of PI3K-AKT-mTOR. The activation of phosphorylation of PI3K-AKT-mTOR by PEDF was blocked after silencing 67LR, as were the protective effects of PEDF on ZO-1. Therefore, we have reason to believe that PEDF increased ZO-1 expression through the 67LR-dependent PI3K-AKT-mTOR signaling pathway, thus maintaining tight junction stability and protecting cardiac function.


Assuntos
Infarto do Miocárdio , Proteínas Proto-Oncogênicas c-akt , Humanos , Células Endoteliais/metabolismo , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Junções Íntimas/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismo , Receptores de Laminina/metabolismo
5.
FEBS Open Bio ; 13(2): 323-340, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36579897

RESUMO

The incidence and mortality rates of cancer are growing rapidly worldwide, with lung cancer being the most commonly occurring cancer in males. Human carcinomas circumvent the inhibitory pathways induced by DNA damage and senescence through the upregulation of telomerase activity. The 37 kDa/67 kDa laminin receptor (LRP/LR) is a cell surface receptor which plays a role in several cancer hallmarks, including metastasis, angiogenesis, cell viability maintenance, apoptotic evasion, and mediating telomerase activity. We have previously shown that the knockdown of LRP/LR with an LRP-specific siRNA significantly impedes adhesion and invasion, induces apoptosis, and inhibits telomerase activity in various cancer cell lines in vitro. Here, we investigated the effect of downregulating LRP/LR with LRP-specific siRNA in A549 lung cancer cells. Downregulation of LRP/LR resulted in a significant decrease in cell viability, migration potential, and telomerase activity, as well as a significant increase in apoptosis. Proteomic analysis further suggested the re-establishment of immune control over the lung cancer cells, a previously unidentified facet of LRP downregulation in cancer. Altogether, we suggest that targeting LRP/LR for downregulation may have therapeutic potential for inhibiting several cancer hallmarks.


Assuntos
Neoplasias Pulmonares , Telomerase , Humanos , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Regulação para Baixo/genética , Telomerase/genética , Telomerase/metabolismo , Proteômica , Receptores de Laminina/genética , Receptores de Laminina/metabolismo , Neoplasias Pulmonares/genética , Moléculas de Adesão Celular/genética
6.
J Nutr Biochem ; 110: 109129, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35977663

RESUMO

It is generally recognized that the main function of α-tocopherol (αToc), which is the most active form of vitamin E, is its antioxidant effect, while non-antioxidant effects have also been reported. We previously found that αToc ameliorates diabetic nephropathy via diacylglycerol kinase alpha (DGKα) activation in vivo, and the activation was not related to the antioxidant effect. However, the underlying mechanism of how αToc activates DGKα have been enigmatic. We report that the membrane-bound 67 kDa laminin receptor (67LR), which has previously been shown to serve as a receptor for epigallocatechin gallate (EGCG), also contains a novel binding site for vitamin E, and its association with Vitamin E mediates DGKα activation by αToc. We employed hydrogen-deuterium exchange mass spectrometry (HDX/MS) and molecular dynamics (MD) simulations to identify the specific binding site of αToc on the 67LR and discovered the conformation of the specific hydrophobic pocket that accommodates αToc. Also, HDX/MS and MD simulations demonstrated the detailed binding of EGCG to a water-exposed hydrophilic site on 67LR, while in contrast αToc binds to a distinct hydrophobic site. We demonstrated that 67LR triggers an important signaling pathway mediating non-antioxidant effects of αToc, such as DGKα activation. This is the first evidence demonstrating a membrane receptor for αToc and one of the underlying mechanisms of a non-antioxidant function for αToc.


Assuntos
Catequina , Diacilglicerol Quinase , Diacilglicerol Quinase/metabolismo , Vitamina E/farmacologia , Receptores de Laminina/metabolismo , Catequina/farmacologia , alfa-Tocoferol , Antioxidantes/farmacologia , Sítios de Ligação
7.
FEBS Lett ; 596(22): 2914-2927, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35971617

RESUMO

Previous studies have shown that amyloid-ß oligomers (AßO) bind with high affinity to cellular prion protein (PrPC ). The AßO-PrPC complex binds to cell-surface co-receptors, including the laminin receptor (67LR). Our current studies revealed that in Neuroscreen-1 cells, 67LR is the major co-receptor involved in the cellular uptake of AßO and AßΟ-induced cell death. Both pharmacological (dibutyryl-cAMP, forskolin and rolipram) and physiological (pituitary adenylate cyclase-activating polypeptide) cAMP-elevating agents decreased cell-surface PrPC and 67LR, thereby attenuating the uptake of AßO and the resultant neuronal cell death. These cAMP protective effects are dependent on protein kinase A, but not dependent on the exchange protein directly activated by cAMP. Conceivably, cAMP protects neuronal cells from AßO-induced cytotoxicity by decreasing cell-surface-associated PrPC and 67LR.


Assuntos
Peptídeos beta-Amiloides , Proteínas PrPC , Peptídeos beta-Amiloides/metabolismo , Proteínas Priônicas , Proteínas PrPC/metabolismo , Laminina/metabolismo , Morte Celular , Receptores de Laminina/genética , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase
8.
Cancer Biomark ; 35(1): 99-109, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35912727

RESUMO

BACKGROUND: Although lysyl-tRNA synthetase (KARS1) is predominantly located in the cytosol, it is also present in the plasma membrane where it stabilizes the 67-kDa laminin receptor (67LR). This physical interaction is strongly increased under metastatic conditions. However, the dynamic interaction of these two proteins and the turnover of KARS1 in the plasma membrane has not previously been investigated. OBJECTIVE: Our objective in this study was to identify the membranous location of KARS1 and 67LR and investigate if this changes with the developmental stage of epithelial ovarian cancer (EOC) and treatment with the inhibitor BC-K01. In addition, we evaluated the therapeutic efficacy of BC-K01 in combination with paclitaxel, as the latter is frequently used to treat patients with EOC. METHODS: Overall survival and prognostic significance were determined in EOC patients according to KARS1 and 67LR expression levels as determined by immunohistochemistry. Changes in the location and expression of KARS1 and 67LR were investigated in vitro after BC-K01 treatment. The effects of this compound on tumor growth and apoptosis were evaluated both in vitro and in vivo. RESULTS: EOC patients with high KARS1 and high 67LR expression had lower progression-free survival rates than those with low expression levels of these two markers. BC-K01 reduced cell viability and increased apoptosis in combination with paclitaxel in EOC cell xenograft mouse models. BC-K01 decreased membranous KARS1 expression, causing a reduction in 67LR membrane expression in EOC cell lines. BC-K01 significantly decreased in vivo tumor weight and number of nodules, especially when used in combination with paclitaxel. CONCLUSIONS: Co-localization of KARS1 and 67LR in the plasma membrane contributes to EOC progression. Inhibition of the KARS1-67LR interaction by BC-K01 suppresses metastasis in EOC.


Assuntos
Lisina-tRNA Ligase , Neoplasias Ovarianas , Animais , Carcinoma Epitelial do Ovário/tratamento farmacológico , Moléculas de Adesão Celular , Feminino , Humanos , Lisina-tRNA Ligase/metabolismo , Camundongos , Neoplasias Ovarianas/tratamento farmacológico , Paclitaxel/farmacologia , Receptores de Laminina/genética , Receptores de Laminina/metabolismo , Proteínas Ribossômicas/genética
9.
Molecules ; 27(16)2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-36014370

RESUMO

The body is equipped with a "food factor-sensing system" that senses food factors, such as polyphenols, sulfur-containing compounds, and vitamins, taken into the body, and plays an essential role in manifesting their physiological effects. For example, (-)-epigallocatechin-3-O-gallate (EGCG), the representative catechin in green tea (Camellia sinensi L.), exerts various effects, including anti-cancer, anti-inflammatory, and anti-allergic effects, when sensed by the cell surficial protein 67-kDa laminin receptor (67LR). Here, we focus on three representative effects of EGCG and provide their specific signaling mechanisms, the 67LR-mediated EGCG-sensing systems. Various components present in foods, such as eriodictyol, hesperetin, sulfide, vitamin A, and fatty acids, have been found to act on the food factor-sensing system and affect the functionality of other foods/food factors, such as green tea extract, EGCG, or its O-methylated derivative at different experimental levels, i.e., in vitro, animal models, and/or clinical trials. These phenomena are observed by increasing or decreasing the activity or expression of EGCG-sensing-related molecules. Such functional interaction between food factors is called "functional food pairing". In this review, we introduce examples of functional food pairings using EGCG.


Assuntos
Catequina , Animais , Catequina/análogos & derivados , Alimento Funcional , Polifenóis/farmacologia , Receptores de Laminina/metabolismo , Proteínas Ribossômicas , Chá
10.
J Cereb Blood Flow Metab ; 42(11): 1979-1999, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35796497

RESUMO

Laminin, a major component of the basal lamina (BL), is a heterotrimeric protein with many isoforms. In the CNS, laminin is expressed by almost all cell types, yet different cells synthesize distinct laminin isoforms. By binding to its receptors, laminin exerts a wide variety of important functions. However, due to the reciprocal and cell-specific expression of laminin in different cells at the neurovascular unit, its functions in blood-brain barrier (BBB) maintenance and BBB repair after injury are not fully understood. In this review, we focus on the expression and functions of laminin and its receptors in the neurovascular unit under both physiological and pathological conditions. We first briefly introduce the structures of laminin and its receptors. Next, the expression and functions of laminin and its receptors in the CNS are summarized in a cell-specific manner. Finally, we identify the knowledge gap in the field and discuss key questions that need to be answered in the future. Our goal is to provide a comprehensive overview on cell-specific expression of laminin and its receptors in the CNS and their functions on BBB integrity.


Assuntos
Barreira Hematoencefálica , Laminina , Membrana Basal/metabolismo , Transporte Biológico , Barreira Hematoencefálica/metabolismo , Laminina/metabolismo , Receptores de Laminina/metabolismo
11.
Sci Rep ; 12(1): 7742, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35546602

RESUMO

Current biomaterials effectively replace biological structures but are limited by infections and long-term material failures. This study examined the molecular mechanisms of radio frequency glow discharge treatments (RFGDT) in mediating the disinfection of biomaterial surfaces and concurrently promoting cell attachment and proliferation. Dental biomaterials were subjected to RFGDT, and viability of oral microbial species, namely Streptococcus mutants (SM), Streptococcus gordonii (SG), Moraxella catarrhalis (MC), and Porphyromonas gingivalis (PG), were assessed. Cell attachment and survival of a pre-odontoblast cell line, MDPC-23, was examined. Finally, mechanistic investigations into redox generation and biological signaling were investigated. Based on their compositions, dental biomaterials induced reactive oxygen species (ROS) following dose-dependent RFGDT. Reduced microbial viability was evident following RFGDT in the catalase-negative (SM and SG) species more prominently than catalase-positive (MC and PG) species. Cell adhesion assays noted improved MDPC-23 attachment and survival. Pretreatments with N-acetylcysteine (NAC) and catalase abrogated these responses. Immunoassays noted redox-induced downstream expression of a laminin receptor, Ribosomal Protein SA, following RFGDT. Thus, RFGDT-induced redox mediates antimicrobial and improves cell responses such as adhesion and proliferation. These observations together provide a mechanistic rationale for the clinical utility of RFGDT with dental biomaterials for regenerative clinical applications.


Assuntos
Laminina , Streptococcus gordonii , Materiais Biocompatíveis/farmacologia , Catalase/farmacologia , Adesão Celular , Laminina/farmacologia , Oxirredução , Porphyromonas gingivalis , Receptores de Laminina , Proteínas Ribossômicas
12.
Cells ; 11(10)2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35626740

RESUMO

Epigallocatechin-3-gallate (EGCG) has widespread effects on adipocyte development. However, the molecular mechanisms of EGCG are not fully understood. We investigate the adipogenic differentiation of human-derived mesenchymal stem cells, including lipid deposition and changes in the expression and phosphorylation of key transcription factors, myosin, protein phosphatase-2A (PP2A), and myosin phosphatase (MP). On day 6 of adipogenic differentiation, EGCG (1-20 µM) suppressed lipid droplet formation, which was counteracted by an EGCG-binding peptide for the 67 kDa laminin receptor (67LR), suggesting that EGCG acts via 67LR. EGCG decreased the phosphorylation of CCAAT-enhancer-binding protein beta via the activation of PP2A in a protein kinase A (PKA)-dependent manner, leading to the partial suppression of peroxisome proliferator-activated receptor gamma (PPARγ) and adiponectin expression. Differentiated cells exhibited a rounded shape, cortical actin filaments, and lipid accumulation. The EGCG treatment induced cell elongation, stress fiber formation, and less lipid accumulation. These effects were accompanied by the degradation of the MP target subunit-1 and increased the phosphorylation of the 20 kDa myosin light chain. Our results suggest that EGCG acts as an agonist of 67LR to inhibit adipogenesis via the activation of PP2A and suppression of MP. These events are coupled with the decreased phosphorylation and expression levels of adipogenic transcription factors and changes in cell shape, culminating in curtailed adipogenesis.


Assuntos
Células-Tronco Mesenquimais , Proteína Fosfatase 2 , Adipogenia , Humanos , Lipídeos/farmacologia , Células-Tronco Mesenquimais/metabolismo , Fosfatase de Miosina-de-Cadeia-Leve/metabolismo , Fosfatase de Miosina-de-Cadeia-Leve/farmacologia , Proteína Fosfatase 2/metabolismo , Receptores de Laminina/metabolismo , Proteínas Ribossômicas , Fatores de Transcrição
13.
Food Funct ; 13(8): 4421-4431, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35302141

RESUMO

Prostate cancer is a major cause of morbidity and mortality in men. Theaflavin-3,3'-digallate (TF-3) is an important functional ingredient of black tea. We aimed to evaluate the cytotoxic effects of TF-3 on prostate cancer and to identify the underlying molecular mechanism. In this study, we explored the effects of TF-3 on prostate cancer in PC-3 cells and in NOD/SCID mice with prostate cancer. The results demonstrated that TF-3 inhibited prostate cancer cell proliferation by regulating the PKCδ/aSMase signaling pathway. The anti-prostate cancer effect of TF-3 was attributed to the expression of the 67 kDa laminin receptor (67LR), which is overexpressed in various cancers, playing a vital role in the growth and metastasis of tumor cells. Stable knockdown of 67LR could efficiently inhibit TF-3 induced apoptosis and cell cycle arrest in PC-3 cells, through interacting with the PKCδ/aSMase signaling pathway. In vivo studies also confirmed the above findings that TF-3 effectively inhibited tumor growth in terms of tumor volume. TF-3 treatment can significantly inhibit tumor growth and up-regulate the phosphorylation of PKCδ and the expression of aSMase in tumor xenografts developed by subcutaneously implanting PC-3 cells and 67LR-overexpressing PC-3 cells in mice. However, in tumor xenografts formed by subcutaneously implanting 67LR-knockdown PC-3 cells, TF-3 has no significant effect on PKCδ/aSMase pathway regulation and tumor growth inhibition.


Assuntos
Catequina , Neoplasias da Próstata , Animais , Antioxidantes/farmacologia , Biflavonoides , Catequina/farmacologia , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Receptores de Laminina/genética , Receptores de Laminina/metabolismo , Transdução de Sinais
14.
Cancer Gene Ther ; 29(10): 1332-1341, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35246611

RESUMO

Ovarian cancer (OC) is one of the most dangerous gynecological malignancies with no effective treatment so far. Pigment epithelium-derived factor (PEDF) has been reported to have ideal anti-tumor effects, but its relationship with the regulation of tumor-associated macrophage polarization is currently unclear. In this study, the mRNA expression of PEDF and macrophage markers were determined in OC tissues from clinic patients and five OC (A2780, SKOV3, CAOV3, OVCAR3, and OVCA433) cell lines through quantitative reverse transcription PCR. Afterwards, tumor growth, cell proliferation and apoptosis, and macrophage polarization in OC tumor-bearing mice with PEDF overexpression were recorded and investigated. Finally, the polarization of macrophages was explored in the presence of lentiviral PEDF overexpression, adipose triglyceride lipase (ATGL) and laminin receptor (LR) knockdown, and mitogen-activated protein kinase (MAPK) pathway inhibition. Our results suggest that PEDF mRNA level is significantly decreased in OC tissues and cells and has a significant negative correlation with OC progression and the level of tumor-related macrophage markers. Furthermore, OC tumors overexpressing PEDF show suppressed growth viability and increased apoptosis rate. The fluorescence activated cell sorting (FACS) analysis reveals that PEDF can promote macrophage polarization in OC tumors towards M1 subtype. Mechanistically, we found that ATGL and extracellular-regulated kinase 1/2 (ERK1/2) signaling are involved in the regulation of macrophage polarization in OC tumors by PEDF. Taken together, these data indicate that the role of PEDF in regulating the polarization of tumor-associated macrophages may make it a potential therapeutic strategy for the treatment of OC in the future.


Assuntos
Neoplasias Ovarianas , Serpinas , Animais , Apoptose/genética , Linhagem Celular Tumoral , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Proteínas do Olho/farmacologia , Feminino , Humanos , Lipase/genética , Lipase/metabolismo , Camundongos , Proteínas Quinases Ativadas por Mitógeno , Fatores de Crescimento Neural , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/terapia , RNA Mensageiro/metabolismo , Receptores de Laminina/metabolismo , Serpinas/genética , Serpinas/metabolismo , Serpinas/farmacologia , Macrófagos Associados a Tumor
15.
Cells ; 11(3)2022 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-35159276

RESUMO

To fight neurodegenerative diseases, several therapeutic strategies have been proposed that, to date, are either ineffective or at the early preclinical stages. Intracellular protein aggregates represent the cause of about 70% of neurodegenerative disorders, such as Alzheimer's disease. Thus, autophagy, i.e., lysosomal degradation of macromolecules, could be employed in this context as a therapeutic strategy. Searching for a compound that stimulates this process led us to the identification of a 37/67kDa laminin receptor inhibitor, NSC48478. We have analysed the effects of this small molecule on the autophagic process in mouse neuronal cells and found that NSC48478 induces the conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3-I) into the LC3-phosphatidylethanolamine conjugate (LC3-II). Interestingly, upon NSC48478 treatment, the contribution of membranes to the autophagic process derived mainly from the non-canonical m-TOR-independent endocytic pathway, involving the Rab proteins that control endocytosis and vesicle recycling. Finally, qRT-PCR analysis suggests that, while the expression of key genes linked to canonical autophagy was unchanged, the main genes related to the positive regulation of endocytosis (pinocytosis and receptor mediated), along with genes regulating vesicle fusion and autolysosomal maturation, were upregulated under NSC48478 conditions. These results strongly suggest that 37/67 kDa inhibitor could be a useful tool for future studies in pathological conditions.


Assuntos
Autofagia , Laminina , Animais , Laminina/farmacologia , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Naftóis/farmacologia , Receptores de Laminina
16.
Int J Biol Macromol ; 201: 480-491, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35063487

RESUMO

A polysaccharide (EMP) was prepared from Monascus purpureus 40,269 through liquid fermentation, and its immunoregulatory effect was investigated to find clues regarding its potential applicability. Structural characterization demonstrated that EMP, with a molecular weight of 83.1 kDa, consists of Xyl, Man, Gal, Ara, Rha, Glc, GalA, and GlcA at a molar ratio of 2.6: 22: 35.1: 7: 1: 29.2: 2.7: 0.6. Immunomodulatory assays involving RAW264.7 cells indicated that EMP exhibits significantly enhanced pinocytic and phagocytic capacities and promotes the secretion of reactive oxygen species, nitric oxide, and cytokines (interleukin-1ß, tumor necrosis factor-α, and interleukin-6) by activating RAW264.7 cells. Moreover, EMP is recognized by Toll-like receptor 4 (TLR-4) and has an immunomodulatory effect by activating the mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways in RAW264.7 cells. Collectively, these results demonstrate that EMP could be used as a functional food for immunological reagents.


Assuntos
Sistema de Sinalização das MAP Quinases , Monascus , NF-kappa B , Polissacarídeos , Receptores de Laminina , Receptor 4 Toll-Like , Animais , Fermentação , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Monascus/química , Monascus/metabolismo , NF-kappa B/metabolismo , Polissacarídeos/química , Polissacarídeos/farmacologia , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo
17.
J Cell Physiol ; 237(1): 687-695, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34318927

RESUMO

Epigallocatechin-3-gallate (EGCG) is the most abundant and biologically active catechins extracted from green tea. The health benefits of EGCG have been extendedly studied. Ovarian steroidogenesis plays a pivotal role in maintaining normal reproductive function. Granulosa cells in the ovary are essential for steroid hormone production. To date, the effect of EGCG on steroidogenesis in human granulosa cells remains unclear. In the present study, we examine the physiological concentrations of EGCG on steroidogenesis in a steroidogenic human granulosa-like tumor cell line, KGN. Our results demonstrate that treatment with EGCG upregulates steroidogenic acute regulatory protein (StAR) expression and increases progesterone (P4) production. EGCG does not affect the expression levels of other steroidogenesis-related enzymes, such as P450 side-chain cleavage enzyme, 3ß-hydroxysteroid dehydrogenase, and aromatase. In addition, we identify the expression of 67-kDa laminin receptor (67LR) in KGN cells. Moreover, EGCG-induced StAR expression and P4 production require the 67LR-mediated activation of the PKA-CREB signaling pathway. These results provide a better understanding of the function of EGCG on ovarian steroidogenesis, which may lead to the development of alternative therapeutic approaches for reproductive disorders.


Assuntos
Células da Granulosa , Progesterona , Catequina/análogos & derivados , Feminino , Células da Granulosa/metabolismo , Humanos , Fosfoproteínas/metabolismo , Progesterona/metabolismo , Receptores de Laminina/metabolismo , Transdução de Sinais
18.
J Oral Pathol Med ; 51(3): 263-271, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34581463

RESUMO

BACKGROUND: Laminin receptor is a non-integrin cell-surface receptor that binds laminin present on the basement membrane. It has been reported to be associated with infiltration and metastasis of various malignant tumors. However, no studies regarding tongue cancer have been reported. This study aimed to clarify the role of laminin receptor in squamous cell carcinoma of the tongue. METHODS: We performed immunohistochemical staining of specimens from 66 patients with squamous cell carcinoma of the tongue and assessed laminin receptor expression and clinicopathological factors. As epithelial-mesenchymal transition has been shown to be associated with infiltration and metastasis of malignant tumors, staining for E-cadherin, vimentin, and N-cadherin were also performed. RESULTS: Of 20 patients with postoperative recurrence, 14 exhibited high laminin receptor expression (p = 0.0025). Kaplan-Meier analysis revealed a significantly shorter time to postoperative recurrence for the high laminin receptor expression group than that for the low laminin receptor expression group (p = 0.0008). Based on multivariate analyses for postoperative recurrence, high laminin receptor expression was associated with poor prognosis (high expression vs. low expression; HR =3.19, 95% CI =0.92-11.08; p = 0.0682). There was a correlation between laminin receptor and N-cadherin (p = 0.0089) but not between laminin receptor and E-cadherin (p = 0.369) or vimentin (p = 0.4221). CONCLUSION: These results suggest that high laminin receptor expression is a useful prognostic factor for postoperative recurrence and may be a target for molecular therapy to treat squamous cell carcinoma of the tongue.


Assuntos
Carcinoma de Células Escamosas , Neoplasias da Língua , Caderinas/metabolismo , Carcinoma de Células Escamosas/patologia , Transição Epitelial-Mesenquimal , Humanos , Laminina , Prognóstico , Receptores de Laminina , Língua/patologia , Neoplasias da Língua/patologia
19.
Bioorg Chem ; 116: 105323, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34482170

RESUMO

Diabetic retinopathy (DR) remains high incidence and accounts for severe impact on vision in diabetics, but its mechanism is still poorly understood. Abnormal migration and proliferation of endothelial cells (ECs) drive neovascular retinopathies, which has an important role in promoting the occurrence and development of DR. In this study, we designed and synthesized a series of PEDF-derived peptides as angiogenesis inhibitors. Especially, compound G24 significantly inhibited the cell proliferation in VEGF-activated human umbilical vein endothelial cells (HUVECs) with IC50 values of 2.88 ± 0.19 µM. Further biological evaluation demonstrated that compound G24 exhibited strong inducing-effects on cell apoptosis and internalization of 67LR, and advanced inhibitory potency in cell migration and angiogenesis formed by HUVECs in vitro. In summary, the optimal compound G24 as a novel angiogenesis inhibitor showed the potentiality in the further research for the treatment for DR.


Assuntos
Inibidores da Angiogênese/farmacologia , Proteínas do Olho/antagonistas & inibidores , Neovascularização Patológica/tratamento farmacológico , Fatores de Crescimento Neural/antagonistas & inibidores , Peptídeos/farmacologia , Receptores de Laminina/antagonistas & inibidores , Inibidores da Angiogênese/síntese química , Inibidores da Angiogênese/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Proteínas do Olho/metabolismo , Humanos , Estrutura Molecular , Fatores de Crescimento Neural/metabolismo , Peptídeos/síntese química , Peptídeos/química , Receptores de Laminina/metabolismo , Serpinas/metabolismo , Relação Estrutura-Atividade
20.
Mol Immunol ; 139: 65-75, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34454186

RESUMO

After decades of cancer vaccine efforts, there is an imperious necessity for novel ideas that may result in better tumor control in patients. We have proposed the use of a novel Variable Epitope Library (VEL) vaccine strategy, which incorporates an unprecedented number of mutated epitopes to target antigenic variability and break tolerance against tumor-associated antigens. Here, we used an oncofetal antigen/immature laminin receptor protein-derived sequence to generate 9-mer and 43-mer VEL immunogens. 4T1 tumor-bearing mice developed epitope-specific CD8+IFN-γ+ and CD4+IFN-γ+ T cell responses after treatment. Tumor and lung analysis demonstrated that VELs could increase the number of tumor-infiltrating lymphocytes with diverse effector functions while reducing the number of immunosuppressive myeloid-derived suppressor and regulatory T cells. Most importantly, VEL immunogens inhibited tumor growth and metastasis after a single dose. The results presented here are consistent with our previous studies and provide evidence for VEL immunogens' feasibility as promising cancer immunotherapy.


Assuntos
Antígenos de Neoplasias/imunologia , Neoplasias da Mama , Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/imunologia , Receptores de Laminina/imunologia , Animais , Vacinas Anticâncer/farmacologia , Modelos Animais de Doenças , Mapeamento de Epitopos/métodos , Feminino , Camundongos , Camundongos Endogâmicos BALB C
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