RESUMO
Research on the energy metabolism of cancer cells is becoming a central element in oncology, and in recent decades, it has allowed us to better understand the mechanisms underlying the onset and chemoresistance of oncological pathologies. Mitochondrial bioenergetic processes, in particular, have proven to be fundamental for the survival of tumor stem cells (CSC), a subpopulation of tumor cells responsible for tumor recurrence, the onset of metastasis, and the failure of conventional anticancer therapies. Over the years, numerous natural products, in particular flavonoids, widely distributed in the plant kingdom, have been shown to interfere with tumor bioenergetics, demonstrating promising antitumor effects. Herein, the anticancer potential of Licoflavanone, a flavanone isolated from the leaves of G. glabra, was explored for the first time in breast cancer cells. The results obtained highlighted a marked antitumor activity that proved to be greater than that mediated by Glabranin or Pinocembrin, flavanones isolated from the same plant matrix. Furthermore, the investigation of Licoflavanone's effects on breast cancer energy metabolism highlighted the inhibitory activity of this natural product on tumor bioenergetics, a mechanism that could underlie its ability to reduce tumor proliferation, invasiveness, and stemness.
Assuntos
Neoplasias da Mama , Metabolismo Energético , Flavanonas , Glycyrrhiza , Humanos , Flavanonas/farmacologia , Flavanonas/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Metabolismo Energético/efeitos dos fármacos , Feminino , Glycyrrhiza/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Células MCF-7RESUMO
Hyaluronic acid (HA) is a glycosaminoglycan widely distributed in the human body, especially in body fluids and the extracellular matrix of tissues. It plays a crucial role not only in maintaining tissue hydration but also in cellular processes such as proliferation, differentiation, and the inflammatory response. HA has demonstrated its efficacy as a powerful bioactive molecule not only for skin antiaging but also in atherosclerosis, cancer, and other pathological conditions. Due to its biocompatibility, biodegradability, non-toxicity, and non-immunogenicity, several HA-based biomedical products have been developed. There is an increasing focus on optimizing HA production processes to achieve high-quality, efficient, and cost-effective products. This review discusses HA's structure, properties, and production through microbial fermentation. Furthermore, it highlights the bioactive applications of HA in emerging sectors of biomedicine.
Assuntos
Ácido Hialurônico , Pele , Humanos , Ácido Hialurônico/química , Fenômenos Químicos , Matriz Extracelular , HidrogéisRESUMO
Dyslipidemia is a lipid metabolism disorder associated with the loss of the physiological homeostasis that ensures safe levels of lipids in the organism. This metabolic disorder can trigger pathological conditions such as atherosclerosis and cardiovascular diseases. In this regard, statins currently represent the main pharmacological therapy, but their contraindications and side effects limit their use. This is stimulating the search for new therapeutic strategies. In this work, we investigated in HepG2 cells the hypolipidemic potential of a picrocrocin-enriched fraction, analyzed by high-resolution 1H NMR and obtained from a saffron extract, the stigmas of Crocus sativus L., a precious spice that has already displayed interesting biological properties. Spectrophotometric assays, as well as expression level of the main enzymes involved in lipid metabolism, have highlighted the interesting hypolipidemic effects of this natural compound; they seem to be exerted through a non-statin-like mechanism. Overall, this work provides new insights into the metabolic effects of picrocrocin, thus confirming the biological potential of saffron and paving the way for in vivo studies that could validate this spice or its phytocomplexes as useful adjuvants in balancing blood lipid homeostasis.
Assuntos
Crocus , Humanos , Crocus/química , Células Hep G2 , Extratos Vegetais/farmacologia , Terpenos/farmacologia , Cicloexenos/farmacologiaRESUMO
Cancer is one of the largest causes of mortality in the world, and due to its incidence, the discovery of novel anticancer drugs is of great importance. Many successful anticancer drugs used in clinical practices are derived from natural products. The genus Santolina is a group of species distributed in the Mediterranean area and used in traditional medicine for their biological properties. The aim of this work was to investigate, for the first time, the multi-target biological potential of Italian Santolina pinnata in relation to their chemical profile, by which an interesting natural source of valuable phytochemicals endowed with anticancer and anti-inflammatory features could be assessed. n-Hexane (EHSP) and methanol (EMSP) extracts were investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography (UHPLC), respectively. Anti-proliferative activity was analyzed on MCF-7 and MDA-MB-231 breast cancer cells, as well as on non-tumorigenic MCF-10A cells, by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Apoptotic death was assessed by comet assay. Cell motility and invasive features were examined in highly invasive MDA-MB-231 by wound-healing scratches, while, in both breast cancer cell lines, by gel-zymography experiments. The anti-inflammatory potential was analyzed by nitric oxide (NO) production and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) staining experiments in bacterial lipopolysaccharides (LPS) which stimulated RAW 264.7 cells. EHSP and EMSP extracts exhibited anticancer activity against breast cancer cells, promoting apoptotic death, as well as decreasing cell migration and invasive behaviours. The highest activity (IC50 of 15.91 µg/mL) was detected against MDA-MB-231 cells, a highly invasive breast cancer cell line. Both extracts were also able to promote anti-inflammatory effects (IC50 values ranging from 27.5 to 61.14 µg/mL), as well as to reduce NO levels by inducing inhibitory effects on NF-κB nuclear translocation in LPS-stimulated RAW 264.7 cells. The different biological behaviours found between the extracts could be related to their different chemical compositions. Herein, the multi-target biological potential of S. pinnata in inducing antitumor and anti-inflammatory effects was comprehensively demonstrated. These findings will provide important stepping-stones for further investigations and may lead to the development of highly effective S. pinnata extract-based treatments for breast cancer and inflammatory processes.
Assuntos
Antineoplásicos , Asteraceae , Neoplasias da Mama , Camundongos , Animais , Humanos , Feminino , Células RAW 264.7 , Lipopolissacarídeos/farmacologia , NF-kappa B/metabolismo , Neoplasias da Mama/tratamento farmacológico , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Cromatografia Gasosa-Espectrometria de Massas , Asteraceae/química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Antineoplásicos/farmacologiaRESUMO
In this study, actively-targeted (CD44-receptors) and dual stimuli (pH/redox)-responsive lipid-polymer nanoparticles were proposed as a delivery vehicle of doxorubicin hydrochloride in triple negative breast cancer cell lines. A phosphatidylcholine lipid film was hydrated with a solution of oxidized hyaluronic acid and doxorubicin, chosen as model drug, followed by a crosslinking reaction with cystamine hydrochloride. The obtained spherical nanoparticles (mean diameter of 30 nm) were found to be efficiently internalized in cancer cells by a receptor-mediated endocytosis process, and to modulate the drug release depending on the pH and redox potential of the surrounding medium. In vitro cytotoxicity assays demonstrated the safety and efficacy of the nanoparticles in enhancing the cytotoxic effect of the free anticancer drug, with the IC50 values being reduced by two and three times in MDA-MB-468 and MDA-MB-231, respectively. The combination of self-assembled phospholipid molecules with a polysaccharide counterpart acting as receptor ligand, and stimuli-responsive chemical moieties, was carried out on smart multifunctional nanoparticles able to actively target breast cancer cells and improve the in vitro anticancer activity of doxorubicin.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/química , Doxorrubicina/farmacologia , Lipídeos/química , Lipossomos/química , Nanopartículas/química , Polissacarídeos/química , Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Feminino , Humanos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/metabolismo , Concentração de Íons de Hidrogênio , Tamanho da PartículaRESUMO
Tumor extracellular vesicles (EVs), as endocytic vesicles able to transport nucleic acids, proteins, and metabolites in recipient cells, have been recognized fundamental mediators of cell-to-cell communication in breast cancer. The biogenesis and release of EVs are highly regulated processes and both the quantity of EVs and their molecular cargo might reflect the metabolic state of the producing cells. We recently demonstrated that the adipokine leptin, whose circulating levels correlate with adipose tissue expansion, is an inducer of EV release from breast cancer cells. Here, we show a specific proteomic signature of EVs released by MCF-7 breast cancer cells grown in the presence of leptin (Lep-EVs), in attempt to find additional molecular effectors linking obesity to breast cancer biology. An analysis of the proteomic profile of Lep-EVs by LC-MS/MS revealed a significant enrichment in biological processes, molecular functions, and cellular components mainly related to mitochondrial machineries and activity, compared to protein content of EVs from untreated breast cancer cells. Metabolic investigations, carried out to assess the autocrine effects of these vesicles on breast cancer cells, revealed that Lep-EVs were able to increase ATP levels in breast cancer cells. This result is associated with increased mitochondrial respiration evaluated by Seahorse analyzer, supporting the concept that Lep-EVs can modulate MCF-7 breast cancer cell oxidative metabolism. Moreover, taking into account the relevance of tumor immune cell crosstalk in the tumor microenvironment (TME), we analyzed the impact of these vesicles on macrophage polarization, the most abundant immune component in the breast TME. We found that tumor-derived Lep-EVs sustain the polarization of M0 macrophages, derived from the human THP-1 monocytic cells, into M2-like tumor-associated macrophages, in terms of metabolic features, phagocytic activity, and increased expression of CD206-positive population. Overall, our results indicate that leptin by inducing the release of EV-enriched in mitochondrial proteins may control the metabolism of MCF-7 breast cancer cells as well as that of macrophages. Characterization of tumor-derived EV protein cargo in an obesity-associated milieu, such as in the presence of elevated leptin levels, might allow identifying unique features and specific metabolic mechanisms useful to develop novel therapeutic approaches for treatment of breast cancer, especially in obese patients.
Assuntos
Neoplasias da Mama , Vesículas Extracelulares , Humanos , Feminino , Proteômica , Neoplasias da Mama/metabolismo , Leptina/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Vesículas Extracelulares/metabolismo , Obesidade/metabolismo , Microambiente TumoralRESUMO
A. baumannii is one of the most important multidrug-resistant microorganisms in hospital units. It is resistant to many classes of antibiotics and the development of new therapeutic strategies is necessary. The aim of this study was to evaluate the antibacterial activity of a set of piperazine-derived thioureas against 13 clinical strains of colistin-resistant A. baumannii. Six derivatives were identified to inhibit bacterial growth of 46% of the A. baumannii strains at low micromolar concentrations (Minimum Inhibitory Concentration from 1.56 to 6.25 µM). A common structural feature in most active compounds was the presence of a 3,5-bis-trifluoromethyl phenyl ring at the thiourea function. In addition, the ability of the compounds to inhibit production of nitric oxide (NO) was examined in RAW 264.7 murine macrophages, highlighting the potential of piperazine-derived thioureas as promising scaffolds for the design of new combined anti-bacterial/anti-inflammatory agents.
Assuntos
Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/síntese química , Anti-Inflamatórios/síntese química , Colistina/farmacologia , Piperazinas/química , Tioureia/síntese química , Animais , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Avaliação Pré-Clínica de Medicamentos , Farmacorresistência Bacteriana , Farmacorresistência Bacteriana Múltipla , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Óxido Nítrico/metabolismo , Células RAW 264.7 , Relação Estrutura-Atividade , Tioureia/farmacologiaRESUMO
Metabolic reprogramming is a hallmark of cancer, which implements a profound metabolic rewiring in order to support a high proliferation rate and to ensure cell survival in its complex microenvironment. Although initial studies considered glycolysis as a crucial metabolic pathway in tumor metabolism reprogramming (i.e., the Warburg effect), recently, the critical role of mitochondria in oncogenesis, tumor progression, and neoplastic dissemination has emerged. In this report, we examined the main mitochondrial metabolic pathways that are altered in cancer, which play key roles in the different stages of tumor progression. Furthermore, we reviewed the function of important molecules inhibiting the main mitochondrial metabolic processes, which have been proven to be promising anticancer candidates in recent years. In particular, inhibitors of oxidative phosphorylation (OXPHOS), heme flux, the tricarboxylic acid cycle (TCA), glutaminolysis, mitochondrial dynamics, and biogenesis are discussed. The examined mitochondrial metabolic network inhibitors have produced interesting results in both preclinical and clinical studies, advancing cancer research and emphasizing that mitochondrial targeting may represent an effective anticancer strategy.
Assuntos
Antineoplásicos/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neoplasias/metabolismo , Animais , Ciclo do Ácido Cítrico/efeitos dos fármacos , Heme/metabolismo , Humanos , Redes e Vias Metabólicas , Mitocôndrias/genética , Neoplasias/tratamento farmacológico , Fosforilação Oxidativa/efeitos dos fármacosRESUMO
Mitochondrial carriers are a family of structurally related proteins responsible for the exchange of metabolites, cofactors and nucleotides between the cytoplasm and mitochondrial matrix. The in silico analysis of the Drosophila melanogaster genome has highlighted the presence of 48 genes encoding putative mitochondrial carriers, but only 20 have been functionally characterized. Despite most Drosophila mitochondrial carrier genes having human homologs and sharing with them 50% or higher sequence identity, D. melanogaster genes display peculiar differences from their human counterparts: (1) in the fruit fly, many genes encode more transcript isoforms or are duplicated, resulting in the presence of numerous subfamilies in the genome; (2) the expression of the energy-producing genes in D. melanogaster is coordinated from a motif known as Nuclear Respiratory Gene (NRG), a palindromic 8-bp sequence; (3) fruit-fly duplicated genes encoding mitochondrial carriers show a testis-biased expression pattern, probably in order to keep a duplicate copy in the genome. Here, we review the main features, biological activities and role in the metabolism of the D. melanogaster mitochondrial carriers characterized to date, highlighting similarities and differences with their human counterparts. Such knowledge is very important for obtaining an integrated view of mitochondrial function in D. melanogaster metabolism.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Translocador 1 do Nucleotídeo Adenina/química , Translocador 1 do Nucleotídeo Adenina/genética , Translocador 1 do Nucleotídeo Adenina/metabolismo , Animais , Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Humanos , Proteínas de Transporte da Membrana Mitocondrial/química , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismoRESUMO
Here, we show that a 2:1 mixture of Brutieridin and Melitidin, termed "BMF", has a statin-like properties, which blocks the action of the rate-limiting enzyme for mevalonate biosynthesis, namely HMGR (3-hydroxy-3-methylglutaryl-CoA-reductase). Moreover, our results indicate that BMF functionally inhibits several key characteristics of CSCs. More specifically, BMF effectively i) reduced ALDH activity, ii) blocked mammosphere formation and iii) inhibited the activation of CSC-associated signalling pathways (STAT1/3, Notch and Wnt/beta-catenin) targeting Rho-GDI-signalling. In addition, BMF metabolically inhibited mitochondrial respiration (OXPHOS) and fatty acid oxidation (FAO). Importantly, BMF did not show the same toxic side-effects in normal fibroblasts that were observed with statins. Lastly, we show that high expression of the mRNA species encoding HMGR is associated with poor clinical outcome in breast cancer patients, providing a potential companion diagnostic for BMF-directed personalized therapy.
Assuntos
Produtos Biológicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Hidroximetilglutaril-CoA Redutases/metabolismo , Ácido Mevalônico/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Óleos de Plantas/química , Inibidores da Dissociação do Nucleotídeo Guanina rho-Específico/metabolismo , Apoptose/efeitos dos fármacos , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Metástase Neoplásica , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Prognóstico , Transdução de Sinais/efeitos dos fármacos , Taxa de SobrevidaRESUMO
The oxoglutarate carrier (OGC) belongs to the mitochondrial carrier family and plays a key role in important metabolic pathways. Here, site-directed mutagenesis was used to conservatively replace lysine 122 by arginine, in order to investigate new structural rearrangements required for substrate translocation. K122R mutant was kinetically characterized, exhibiting a significant Vmax reduction with respect to the wild-type (WT) OGC, whereas Km value was unaffected, implying that this substitution does not interfere with 2-oxoglutarate binding site. Moreover, K122R mutant was more inhibited by several sulfhydryl reagents with respect to the WT OGC, suggesting that the reactivity of some cysteine residues towards these Cys-specific reagents is increased in this mutant. Different sulfhydryl reagents were employed in transport assays to test the effect of the cysteine modifications on single-cysteine OGC mutants named C184, C221, C224 (constructed in the WT background) and K122R/C184, K122R/C221, K122R/C224 (constructed in the K122R background). Cysteines 221 and 224 were more deeply influenced by some sulfhydryl reagents in the K122R background. Furthermore, the presence of 2-oxoglutarate significantly enhanced the degree of inhibition of K122R/C221, K122R/C224 and C224 activity by the sulfhydryl reagent 2-Aminoethyl methanethiosulfonate hydrobromide (MTSEA), suggesting that cysteines 221 and 224, together with K122, take part to structural rearrangements required for the transition from the c- to the m-state during substrate translocation. Our results are interpreted in the light of the homology model of BtOGC, built by using as a template the X-ray structure of the bovine ADP/ATP carrier isoform 1 (AAC1).
Assuntos
Cisteína/química , Ácidos Cetoglutáricos/química , Proteínas de Membrana Transportadoras/química , Mitocôndrias/química , Translocases Mitocondriais de ADP e ATP/química , Animais , Arginina/química , Arginina/metabolismo , Sítios de Ligação , Bovinos , Cisteína/metabolismo , Metanossulfonato de Etila/análogos & derivados , Metanossulfonato de Etila/química , Expressão Gênica , Ácidos Cetoglutáricos/metabolismo , Cinética , Lisina/química , Lisina/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Mitocôndrias/metabolismo , Translocases Mitocondriais de ADP e ATP/genética , Translocases Mitocondriais de ADP e ATP/metabolismo , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Ligação Proteica , Domínios Proteicos , Estrutura Secundária de Proteína , Homologia Estrutural de Proteína , Especificidade por SubstratoRESUMO
Zinc (Zn) is an essential trace mineral that contributes to the regulation of several cellular functions; however, it may be also implicated in the progression of breast cancer through different mechanisms. It has been largely reported that the classical estrogen receptor (ER), as well as the G protein estrogen receptor (GPER, previously known as GPR30) can exert a main role in the development of breast tumors. In the present study, we demonstrate that zinc chloride (ZnCl2 ) involves GPER in the activation of insulin-like growth factor receptor I (IGF-IR)/epidermal growth factor receptor (EGFR)-mediated signaling, which in turn triggers downstream pathways like ERK and AKT in breast cancer cells, and main components of the tumor microenvironment namely cancer-associated fibroblasts (CAFs). Further corroborating these findings, ZnCl2 stimulates a functional crosstalk of GPER with IGF-IR and EGFR toward the transcription of diverse GPER target genes. Then, we show that GPER contributes to the stimulatory effects induced by ZnCl2 on cell-cycle progression, proliferation, and migration of breast cancer cells as well as migration of CAFs. Together, our data provide novel insights into the molecular mechanisms through which zinc may exert stimulatory effects in breast cancer cells and CAFs toward tumor progression. © 2016 Wiley Periodicals, Inc.
Assuntos
Neoplasias da Mama/metabolismo , Fibroblastos Associados a Câncer/patologia , Cloretos/metabolismo , Receptores ErbB/metabolismo , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Somatomedina/metabolismo , Transdução de Sinais , Compostos de Zinco/metabolismo , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/patologia , Fibroblastos Associados a Câncer/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Feminino , HumanosRESUMO
The mitochondrial carriers are members of a family of transport proteins that mediate solute transport across the inner mitochondrial membrane. Two isoforms of the glutamate carriers, GC1 and GC2 (encoded by the SLC25A22 and SLC25A18 genes, respectively), have been identified in humans. Two independent mutations in SLC25A22 are associated with severe epileptic encephalopathy. In the present study we show that two genes (CG18347 and CG12201) phylogenetically related to the human GC encoding genes are present in the D. melanogaster genome. We have functionally characterized the proteins encoded by CG18347 and CG12201, designated as DmGC1p and DmGC2p respectively, by overexpression in Escherichia coli and reconstitution into liposomes. Their transport properties demonstrate that DmGC1p and DmGC2p both catalyze the transport of glutamate across the inner mitochondrial membrane. Computational approaches have been used in order to highlight residues of DmGC1p and DmGC2p involved in substrate binding. Furthermore, gene expression analysis during development and in various adult tissues reveals that CG18347 is ubiquitously expressed in all examined D. melanogaster tissues, while the expression of CG12201 is strongly testis-biased. Finally, we identified mitochondrial glutamate carrier orthologs in 49 eukaryotic species in order to attempt the reconstruction of the evolutionary history of the glutamate carrier function. Comparison of the exon/intron structure and other key features of the analyzed orthologs suggests that eukaryotic glutamate carrier genes descend from an intron-rich ancestral gene already present in the common ancestor of lineages that diverged as early as bilateria and radiata.
Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Evolução Molecular , Ácido Glutâmico/metabolismo , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Sequência de Aminoácidos , Sistema X-AG de Transporte de Aminoácidos/química , Animais , Sítios de Ligação , Primers do DNA/química , Primers do DNA/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/isolamento & purificação , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Éxons/genética , Humanos , Concentração de Íons de Hidrogênio , Íntrons/genética , Proteínas de Transporte da Membrana Mitocondrial/química , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/isolamento & purificação , Proteínas Mitocondriais/química , Modelos Moleculares , Dados de Sequência Molecular , Reação em Cadeia da Polimerase em Tempo Real , Homologia de Sequência de AminoácidosRESUMO
The citrate carrier (CIC), a nuclear-encoded protein located in the mitochondrial inner membrane, plays an important metabolic role in the transport of acetyl-CoA from the mitochondrion to the cytosol in the form of citrate for fatty acid and cholesterol synthesis. Citrate has been reported to be essential for fibroblast differentiation into fat cells. Because peroxisome proliferator-activated receptor-gamma (PPARγ) is known to be one of the master regulators of adipogenesis, we aimed to study the regulation of CIC by the PPARγ ligand rosiglitazone (BRL) in 3T3-L1 fibroblasts and in adipocytes. We demonstrated that BRL up-regulated CIC mRNA and protein levels in fibroblasts, while it did not elicit any effects in mature adipocytes. The enhancement of CIC levels upon BRL treatment was reversed using the PPARγ antagonist GW9662, addressing how this effect was mediated by PPARγ. Functional experiments using a reporter gene containing rat CIC promoter showed that BRL enhanced CIC promoter activity. Mutagenesis studies, electrophoretic-mobility-shift assay and chromatin-immunoprecipitation analysis revealed that upon BRL treatment, PPARγ and Sp1 are recruited on the Sp1-containing region within the CIC promoter, leading to an increase in CIC expression. In addition, mithramycin, a specific inhibitor for Sp1-DNA binding activity, abolished the PPARγ-mediated up-regulation of CIC in fibroblasts. The stimulatory effects of BRL disappeared in mature adipocytes in which PPARγ/Sp1 complex recruited SMRT corepressor to the Sp1 site of the CIC promoter. Taken together, our results contribute to clarify the molecular mechanisms by which PPARγ regulates CIC expression during the differentiation stages of fibroblasts into mature adipocytes.
Assuntos
Adipócitos/metabolismo , Adipogenia/fisiologia , Fibroblastos/metabolismo , Mitocôndrias/metabolismo , PPAR gama/metabolismo , Proteínas Repressoras/genética , Células 3T3-L1 , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Imunoprecipitação da Cromatina , Ensaio de Desvio de Mobilidade Eletroforética , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Luciferases/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Correpressor 2 de Receptor Nuclear/antagonistas & inibidores , Correpressor 2 de Receptor Nuclear/genética , Correpressor 2 de Receptor Nuclear/metabolismo , PPAR gama/genética , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Repressoras/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rosiglitazona , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Tiazolidinedionas/farmacologia , Ativação Transcricional , Regulação para CimaRESUMO
The citrate carrier (CiC), characteristic of animals, and the dicarboxylate-tricarboxylate carrier (DTC), characteristic of plants and protozoa, belong to the mitochondrial carrier protein family whose members are responsible for the exchange of metabolites, cofactors, and nucleotides between the cytoplasm and the mitochondrial matrix. Most of the functional data on these transporters are obtained from the studies performed with the protein purified from rat, eel yeast, and maize mitochondria or recombinant proteins from different sources incorporated into phospholipid vesicles (liposomes). The functional data indicate that CiC is responsible for the efflux of acetyl-CoA from the mitochondria to the cytosol in the form of citrate, the primer for fatty acid, cholesterol synthesis, and histone acetylation. Like the CiC, the citrate exported by DTC from the mitochondria to the cytosol in exchange for oxaloacetate can be cleaved by citrate lyase to acetyl-CoA and oxaloacetate and used for fatty acid elongation and isoprenoid synthesis. In addition to its role in fatty acid synthesis, CiC is involved in other processes such as gluconeogenesis, insulin secretion, inflammation, and cancer progression, whereas DTC is involved in the production of glycerate, nitrogen assimilation, ripening of fruits, ATP synthesis, and sustaining of respiratory flux in fruit cells. This review provides an assessment of the current understanding of CiC and DTC structural and biochemical characteristics, underlying the structure-function relationship of these carriers. Furthermore, a phylogenetic relationship between CiC and DTC is proposed.
Assuntos
Proteínas de Transporte/fisiologia , Transportadores de Ácidos Dicarboxílicos/fisiologia , Animais , Sequência de Bases , Humanos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/fisiologia , Dados de Sequência Molecular , Especificidade de Órgãos , Filogenia , Regiões Promotoras GenéticasRESUMO
Raspberry (Rubus idaeus L.) is a fruit of great interest due to its aroma, nutritional properties, and the presence of many bioactive compounds. However, differences among cultivation systems can affect its composition and, consequently, its potential bioactivity. Herein, for the first time, raspberries grown in an aeroponic system were investigated for their chemical profile and antioxidant and anti-inflammatory activity, as well as their enzyme (α-glucosidase and pancreatic lipase) inhibitory properties in comparison to wild and conventionally cultivated fruits. High-performance liquid chromatography coupled with diode array detection (HPLC-DAD) analyses revealed the presence of gallic acid, caffeic acid, chlorogenic acid, p-coumaric acid, ferulic acid, rutin, and catechin in all the samples. The extracts exhibited in vitro anti-inflammatory activity (inhibition of nitric oxide production) regardless of the cultivation method. Of particular interest is the ability of raspberries to inhibit pancreatic lipase. With the exception of the ß-carotene bleaching test, the raspberries grown in conventional and aeroponic systems were more active in terms of antioxidants than wild fruits, as evidenced by the ABTS (IC50 in the range 1.6-3.4 µg/mL), DPPH (IC50 in the range 8.9-28.3 µg/mL), and FRAP tests (24.6-44.9 µM Fe(II)/g). The raspberries from aeroponic cultivation were generally able to exert the same bioactivity as those obtained from both conventionally cultivated and wild fruits, supporting the consideration that in the future, this technology could reshape agriculture by mitigating resource constraints, fostering sustainable practices and increasing yields.
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Activation of lipid metabolism is an early event in carcinogenesis and a central hallmark of many tumors. Fatty acid synthase (FASN) is a key lipogenic enzyme catalyzing the terminal steps in the de novo biogenesis of fatty acids. In cancer cells, FASN may act as a metabolic oncogene, given that it confers growth and survival advantages to these cells, whereas its inhibition effectively and selectively kills tumor cells. Hormones such as estrogens and growth factors contribute to the transcriptional regulation of FASN expression also through the activation of downstream signaling and a cross-talk among diverse transduction pathways. In this study, we demonstrate for the first time that 17ß-estradiol (E2) and the selective GPER ligand G-1 regulate FASN expression and activity through the GPER-mediated signaling, which involved the EGF receptor/ERK/c-Fos/AP1 transduction pathway, as ascertained by using specific pharmacological inhibitors, performing gene-silencing experiments and ChIP assays in breast SkBr3, colorectal LoVo, hepatocarcinoma HepG2 cancer cells, and breast cancer-associated fibroblasts. In addition, the proliferative effects induced by E2 and G-1 in these cells involved FASN as the inhibitor of its activity, named cerulenin, abolished the growth response to both ligands. Our data suggest that GPER may be included among the transduction mediators involved by estrogens in regulating FASN expression and activity in cancer cells and cancer-associated fibroblasts that strongly contribute to cancer progression.
Assuntos
Estradiol/farmacologia , Estrogênios/farmacologia , Ácido Graxo Sintase Tipo I/biossíntese , Fibroblastos/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Cerulenina/farmacologia , Receptores ErbB/genética , Receptores ErbB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Ácido Graxo Sintase Tipo I/antagonistas & inibidores , Ácido Graxo Sintase Tipo I/genética , Inibidores da Síntese de Ácidos Graxos/farmacologia , Feminino , Fibroblastos/patologia , Células Hep G2 , Humanos , Neoplasias/genética , Neoplasias/patologia , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
Breast cancer remains the greatest cause of cancer-related death in women worldwide. Its aggressiveness and progression derive from intricate processes that occur simultaneously both within the tumour itself and in the neighbouring cells that make up its microenvironment. The aim of the present work was firstly to study how elevated cholesterol levels increase tumour aggressiveness. Herein, we demonstrate that cholesterol, by activating ERRα pathway, promotes epithelium-mesenchymal transition (EMT) in breast cancer cells (MCF-7 and MDA-MB-231) as well as the release of pro-inflammatory factors able to orchestrate the tumour microenvironment. A further objective of this work was to study the close symbiosis between tumour cells and the microenvironment. Our results allow us to highlight, for the first time, that breast cancer cells exposed to high cholesterol levels promote (a) greater macrophages infiltration with induction of an M2 phenotype, (b) angiogenesis and endothelial branching, as well as (c) a cancer-associated fibroblasts (CAFs) phenotype. The effects observed could be due to direct activation of the ERRα pathway by high cholesterol levels, since the simultaneous inhibition of this pathway subverts such effects. Overall, these findings enable us to identify the cholesterol-ERRα synergy as an interesting target for breast cancer treatment.
Assuntos
Neoplasias da Mama , Hipercolesterolemia , Microambiente Tumoral , Feminino , Humanos , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Colesterol/efeitos adversos , Hipercolesterolemia/complicações , Hipercolesterolemia/genética , Hipercolesterolemia/metabolismo , Microambiente Tumoral/genética , Microambiente Tumoral/fisiologia , Receptor ERRalfa Relacionado ao EstrogênioRESUMO
Prostate cancer is the second most common cancer in men. Although epidemiologic studies show that a higher intake of polyphenols, curcumin (CUR), and quercetin (QRT), in particular, result in lower prostate cancer risk, the chemopreventive mechanisms underlying the effects of CUR and QRT have not been fully understood yet, and most investigations were conducted with individual compounds. Here, we investigated the anticancer and anti-inflammatory effects of CUR in combination with QRT, respectively, in a human prostate cancer cell line, PC-3, and in LPS-stimulated RAW 264.7 cells, and found that their combination significantly inhibited proliferation and arrested the cell cycle, inducing apoptosis, so exhibiting synergic activities stronger than single drug use. Moreover, via their antioxidant effects, the combination of CUR and QRT modulated several inflammation-mediated signaling pathways (ROS, nitric oxide, and pro-inflammatory cytokines) thus helping protect cells from undergoing molecular changes that trigger carcinogenesis. Although additional studies, including in vivo experiments and translational studies, are required, this study raises the possibility of their use as a safe, effective, and affordable therapeutic approach to prostate cancer.
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Background: Berry fruits are recognized as a "superfood" due to their high content of bioactive compounds and health benefits. Scope and approach: Herein, extracts of Cornus sanguinea and Cornus mas fresh and dried fruits obtained by different extraction procedures (ethanolic and hydroalcoholic maceration, ultrasound-assisted extraction, and Soxhlet apparatus) were analysed using liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry (LC-ESI-QTOF-MS) and compared to identify the main healthy compounds and their impact on the inhibition of key enzymes (pancreatic lipase, α-glucosidase, and α-amylase) associated with metabolic disorders. The antioxidant activity and inhibition of nitric oxide (NO) and NF-κB pathway were also investigated. Key findings and conclusions: Flavonoids, iridoids, and phenolic acids were the main classes of identified compounds. Herein, kaempferol 3-O-galactoside, kaempferol 3-O-glucoside, quercetin, quercetin 3-O-xyloside, and myricetin 3-O-galactoside were detected for the first time in C. sanguinea. Remarkable antioxidant effects and promising α-glucosidase and lipase inhibitory activity were observed with extracts obtained by hydroalcoholic maceration of both Cornus dried fruits. Consequently, these extracts were subjected to fractionation using Amberlite XAD-16 resin. The most promising biological activities, which are attributed to the presence of some flavonoids and iridoids, were detected with the C. sanguinea fractions, in particular SD2(II). The results of this study offer new insights into the potential development of functional foods, nutraceuticals, and food supplements using the Cornus species.