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1.
Cell ; 176(5): 1098-1112.e18, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30794774

RESUMO

Increased levels of intestinal bile acids (BAs) are a risk factor for colorectal cancer (CRC). Here, we show that the convergence of dietary factors (high-fat diet) and dysregulated WNT signaling (APC mutation) alters BA profiles to drive malignant transformations in Lgr5-expressing (Lgr5+) cancer stem cells and promote an adenoma-to-adenocarcinoma progression. Mechanistically, we show that BAs that antagonize intestinal farnesoid X receptor (FXR) function, including tauro-ß-muricholic acid (T-ßMCA) and deoxycholic acid (DCA), induce proliferation and DNA damage in Lgr5+ cells. Conversely, selective activation of intestinal FXR can restrict abnormal Lgr5+ cell growth and curtail CRC progression. This unexpected role for FXR in coordinating intestinal self-renewal with BA levels implicates FXR as a potential therapeutic target for CRC.


Assuntos
Neoplasias Intestinais/metabolismo , Células-Tronco Neoplásicas/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Ácidos e Sais Biliares/metabolismo , Linhagem Celular , Proliferação de Células/genética , Neoplasias Colorretais/metabolismo , Ácido Desoxicólico/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Intestinais/genética , Intestinos , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Neoplásicas/fisiologia , Organoides/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Fatores de Risco , Transdução de Sinais , Ácido Taurocólico/análogos & derivados , Ácido Taurocólico/metabolismo , Via de Sinalização Wnt/genética , Via de Sinalização Wnt/fisiologia
2.
Cell ; 173(5): 1135-1149.e15, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29754817

RESUMO

A primary cause of disease progression in type 2 diabetes (T2D) is ß cell dysfunction due to inflammatory stress and insulin resistance. However, preventing ß cell exhaustion under diabetic conditions is a major therapeutic challenge. Here, we identify the vitamin D receptor (VDR) as a key modulator of inflammation and ß cell survival. Alternative recognition of an acetylated lysine in VDR by bromodomain proteins BRD7 and BRD9 directs association to PBAF and BAF chromatin remodeling complexes, respectively. Mechanistically, ligand promotes VDR association with PBAF to effect genome-wide changes in chromatin accessibility and enhancer landscape, resulting in an anti-inflammatory response. Importantly, pharmacological inhibition of BRD9 promotes PBAF-VDR association to restore ß cell function and ameliorate hyperglycemia in murine T2D models. These studies reveal an unrecognized VDR-dependent transcriptional program underpinning ß cell survival and identifies the VDR:PBAF/BAF association as a potential therapeutic target for T2D.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Receptores de Calcitriol/metabolismo , Fatores de Transcrição/metabolismo , Vitamina D/farmacologia , Animais , Calcitriol/análogos & derivados , Calcitriol/farmacologia , Montagem e Desmontagem da Cromatina , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Humanos , Insulina/sangue , Insulina/metabolismo , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Mutagênese Sítio-Dirigida , Fosforilação Oxidativa/efeitos dos fármacos , Ligação Proteica , Interferência de RNA , RNA Guia de Cinetoplastídeos/genética , RNA Interferente Pequeno/metabolismo , Receptores de Calcitriol/antagonistas & inibidores , Receptores de Calcitriol/genética , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Transcrição Gênica/efeitos dos fármacos
3.
Proc Natl Acad Sci U S A ; 120(21): e2217826120, 2023 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-37192160

RESUMO

Molecular classification of gastric cancer (GC) identified a subgroup of patients showing chemoresistance and poor prognosis, termed SEM (Stem-like/Epithelial-to-mesenchymal transition/Mesenchymal) type in this study. Here, we show that SEM-type GC exhibits a distinct metabolic profile characterized by high glutaminase (GLS) levels. Unexpectedly, SEM-type GC cells are resistant to glutaminolysis inhibition. We show that under glutamine starvation, SEM-type GC cells up-regulate the 3 phosphoglycerate dehydrogenase (PHGDH)-mediated mitochondrial folate cycle pathway to produce NADPH as a reactive oxygen species scavenger for survival. This metabolic plasticity is associated with globally open chromatin structure in SEM-type GC cells, with ATF4/CEBPB identified as transcriptional drivers of the PHGDH-driven salvage pathway. Single-nucleus transcriptome analysis of patient-derived SEM-type GC organoids revealed intratumoral heterogeneity, with stemness-high subpopulations displaying high GLS expression, a resistance to GLS inhibition, and ATF4/CEBPB activation. Notably, coinhibition of GLS and PHGDH successfully eliminated stemness-high cancer cells. Together, these results provide insight into the metabolic plasticity of aggressive GC cells and suggest a treatment strategy for chemoresistant GC patients.


Assuntos
Fosfoglicerato Desidrogenase , Neoplasias Gástricas , Humanos , Fosfoglicerato Desidrogenase/genética , Fosfoglicerato Desidrogenase/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Linhagem Celular Tumoral , Glutamina/metabolismo , Nutrientes
4.
BMC Med ; 21(1): 38, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36726166

RESUMO

BACKGROUND: Cancer cells have developed molecular strategies to cope with evolutionary stressors in the dynamic tumor microenvironment. Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) is a metabolic rheostat that regulates diverse cellular adaptive behaviors, including growth and survival. However, the mechanistic role of PGC1α in regulating cancer cell viability under metabolic and genotoxic stress remains elusive. METHODS: We investigated the PGC1α-mediated survival mechanisms in metabolic stress (i.e., glucose deprivation-induced metabolic stress condition)-resistant cancer cells. We established glucose deprivation-induced metabolic stress-resistant cells (selected cells) from parental tumor cells and silenced or overexpressed PGC1α in selected and parental tumor cells. RESULTS: Several in vitro and in vivo mouse experiments were conducted to elucidate the contribution of PGC1α to cell viability in metabolic stress conditions. Interestingly, in the mouse xenograft model of patient-derived drug-resistant cancer cells, each group treated with an anti-cancer drug alone showed no drastic effects, whereas a group that was co-administered an anti-cancer drug and a specific PMCA inhibitor (caloxin or candidate 13) showed marked tumor shrinkage. CONCLUSIONS: Our results suggest that PGC1α is a key regulator of anti-apoptosis in metabolic and genotoxic stress-resistant cells, inducing PMCA expression and allowing survival in glucose-deprived conditions. We have discovered a novel therapeutic target candidate that could be employed for the treatment of patients with refractory cancers.


Assuntos
Neoplasias , Camundongos , Humanos , Animais , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Neoplasias/tratamento farmacológico , Estresse Fisiológico , Resistência a Medicamentos , Microambiente Tumoral
5.
Int J Mol Sci ; 24(16)2023 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-37629174

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive form of pancreatic cancer with a poor prognosis and low survival rates. The prognostic and predictive biomarkers of PDAC are still largely unknown. The receptor CD74 was recently identified as a regulator of oncogenic properties in various cancers. However, the precise molecular mechanism of CD74 action in PDAC remains little understood. We investigated the role of CD74 by silencing CD74 in the pancreatic cancer cell line Capan-1. CD74 knockdown led to reductions in cell proliferation, migration, and invasion and increased apoptosis. Moreover, silencing CD74 resulted in the decreased expression and secretion of S100A8 and S100A9. An indirect co-culture of fibroblasts and tumor cells revealed that fibroblasts exposed to conditioned media from CD74 knockdown cells exhibited a reduced expression of inflammatory cytokines, suggesting a role of CD74 in influencing cytokine secretion in the tumor microenvironment. Overall, our study provides valuable insights into the critical role of CD74 in regulating the oncogenic properties of pancreatic cancer cells and its influence on the expression and secretion of S100A8 and S100A9. Taken together, these findings indicate CD74 as a potential diagnostic biomarker and therapeutic target for pancreatic cancer.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Microambiente Tumoral , Calgranulina A/genética , Calgranulina B/genética , Neoplasias Pancreáticas/genética , Carcinoma Ductal Pancreático/genética , Neoplasias Pancreáticas
6.
Proc Natl Acad Sci U S A ; 116(42): 21140-21149, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31570593

RESUMO

Retinoic acid-related orphan receptor α (RORα) functions as a transcription factor for various biological processes, including circadian rhythm, cancer, and metabolism. Here, we generate intestinal epithelial cell (IEC)-specific RORα-deficient (RORαΔIEC) mice and find that RORα is crucial for maintaining intestinal homeostasis by attenuating nuclear factor κB (NF-κB) transcriptional activity. RORαΔIEC mice exhibit excessive intestinal inflammation and highly activated inflammatory responses in the dextran sulfate sodium (DSS) mouse colitis model. Transcriptome analysis reveals that deletion of RORα leads to up-regulation of NF-κB target genes in IECs. Chromatin immunoprecipitation analysis reveals corecruitment of RORα and histone deacetylase 3 (HDAC3) on NF-κB target promoters and subsequent dismissal of CREB binding protein (CBP) and bromodomain-containing protein 4 (BRD4) for transcriptional repression. Together, we demonstrate that RORα/HDAC3-mediated attenuation of NF-κB signaling controls the balance of inflammatory responses, and therapeutic strategies targeting this epigenetic regulation could be beneficial to the treatment of chronic inflammatory diseases, including inflammatory bowel disease (IBD).


Assuntos
Homeostase/fisiologia , Inflamação/metabolismo , Intestinos/fisiologia , Receptores Nucleares Órfãos/metabolismo , Animais , Epigênese Genética/fisiologia , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica/fisiologia , Transcriptoma/fisiologia
7.
Int J Mol Sci ; 23(2)2022 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-35054884

RESUMO

Thyroid cancer (TC) includes tumors of follicular cells; it ranges from well differentiated TC (WDTC) with generally favorable prognosis to clinically aggressive poorly differentiated TC (PDTC) and undifferentiated TC (UTC). Papillary thyroid cancer (PTC) is a WDTC and the most common type of thyroid cancer that comprises almost 70-80% of all TC. PTC can present as a solid, cystic, or uneven mass that originates from normal thyroid tissue. Prognosis of PTC is excellent, with an overall 10-year survival rate >90%. However, more than 30% of patients with PTC advance to recurrence or metastasis despite anti-cancer therapy; consequently, systemic therapy is limited, which necessitates expansion of improved clinical approaches. We strived to elucidate genetic distinctions due to patient-derived anti-cancer drug-sensitive or -resistant PTC, which can support in progress novel therapies. Patients with histologically proven PTC were evaluated. PTC cells were gained from drug-sensitive and -resistant patients and were compared using mRNA-Seq. We aimed to assess the in vitro and in vivo synergistic anti-cancer effects of a novel combination therapy in patient-derived refractory PTC. This combination therapy acts synergistically to promote tumor suppression compared with either agent alone. Therefore, genetically altered combination therapy might be a novel therapeutic approach for refractory PTC.


Assuntos
Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Câncer Papilífero da Tireoide/tratamento farmacológico , Adulto , Idoso , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Paclitaxel/uso terapêutico , Compostos de Fenilureia/uso terapêutico , Prognóstico , Quinolinas/uso terapêutico , RNA-Seq , Sorafenibe/uso terapêutico , Câncer Papilífero da Tireoide/genética , Câncer Papilífero da Tireoide/fisiopatologia , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Nature ; 528(7580): 137-41, 2015 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-26580014

RESUMO

Age-associated insulin resistance (IR) and obesity-associated IR are two physiologically distinct forms of adult-onset diabetes. While macrophage-driven inflammation is a core driver of obesity-associated IR, the underlying mechanisms of the obesity-independent yet highly prevalent age-associated IR are largely unexplored. Here we show, using comparative adipo-immune profiling in mice, that fat-resident regulatory T cells, termed fTreg cells, accumulate in adipose tissue as a function of age, but not obesity. Supporting the existence of two distinct mechanisms underlying IR, mice deficient in fTreg cells are protected against age-associated IR, yet remain susceptible to obesity-associated IR and metabolic disease. By contrast, selective depletion of fTreg cells via anti-ST2 antibody treatment increases adipose tissue insulin sensitivity. These findings establish that distinct immune cell populations within adipose tissue underlie ageing- and obesity-associated IR, and implicate fTreg cells as adipo-immune drivers and potential therapeutic targets in the treatment of age-associated IR.


Assuntos
Tecido Adiposo/citologia , Tecido Adiposo/imunologia , Envelhecimento/imunologia , Resistência à Insulina/imunologia , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Animais , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Inflamação/imunologia , Inflamação/metabolismo , Macrófagos/imunologia , Masculino , Síndrome Metabólica/imunologia , Síndrome Metabólica/metabolismo , Camundongos , Obesidade/metabolismo
9.
Proc Natl Acad Sci U S A ; 115(41): 10381-10386, 2018 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-30254164

RESUMO

Nuclear hormone receptors (NRs), such as retinoic acid receptors (RARs), play critical roles in vertebrate development and homeostasis by regulating target gene transcription. Their activity is controlled by ligand-dependent release of corepressors and subsequent recruitment of coactivators, but how these individual receptor modes contribute to development are unknown. Here, we show that mice carrying targeted knockin mutations in the corepressor Silencing Mediator of Retinoid and Thyroid hormone receptor (SMRT) that specifically disable SMRT function in NR signaling (SMRTmRID), display defects in cranial neural crest cell-derived structures and posterior homeotic transformations of axial vertebrae. SMRTmRID embryos show enhanced transcription of RAR targets including Hox loci, resulting in respecification of vertebral identities. Up-regulated histone acetylation and decreased H3K27 methylation are evident in the Hox loci whose somitic expression boundaries are rostrally shifted. Furthermore, enhanced recruitment of super elongation complex is evident in rapidly induced non-Pol II-paused targets in SMRTmRID embryonic stem cells. These results demonstrate that SMRT-dependent repression of RAR is critical to establish and maintain the somitic Hox code and segmental identity during fetal development via epigenetic marking of target loci.


Assuntos
Regulação da Expressão Gênica , Genes Homeobox/genética , Correpressor 2 de Receptor Nuclear/fisiologia , Somitos/fisiologia , Transcrição Gênica , Tretinoína/farmacologia , Animais , Antineoplásicos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Crista Neural/citologia , Crista Neural/fisiologia , Somitos/citologia , Somitos/efeitos dos fármacos
10.
Int J Mol Sci ; 22(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202606

RESUMO

Cancer is heterogeneous among patients, requiring a thorough understanding of molecular subtypes and the establishment of therapeutic strategies based on its behavior. Gastric cancer (GC) is adenocarcinoma with marked heterogeneity leading to different prognoses. As an effort, we previously identified a stem-like subtype, which is prone to metastasis, with the worst prognosis. Here, we propose FNBP1 as a key to high-level cell motility, present only in aggressive GC cells. FNBP1 is also up-regulated in both the GS subtype from the TCGA project and the EMT subtype from the ACRG study, which include high portions of diffuse histologic type. Ablation of FNBP1 in the EMT-type GC cell line brought changes in the cell periphery in transcriptomic analysis. Indeed, loss of FNBP1 resulted in the loss of invasive ability, especially in a three-dimensional culture system. Live imaging indicated active movement of actin in FNBP1-overexpressed cells cultured in an extracellular matrix dome. To find the transcription factor which drives FNBP1 expression in an EMT-type GC cell line, the FNBP1 promoter region and DNA binding motifs were analyzed. Interestingly, the Sp1 motif was abundant in the promoter, and pharmacological inhibition and knockdown of Sp1 down-regulated FNBP1 promoter activity and the transcription level, respectively. Taken together, our results propose Sp1-driven FNBP1 as a key molecule explaining aggressiveness in EMT-type GC cells.


Assuntos
Transição Epitelial-Mesenquimal/genética , Proteínas de Ligação a Ácido Graxo/genética , Regulação Neoplásica da Expressão Gênica , Fator de Transcrição Sp1/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Sequência de Bases , Sítios de Ligação , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Matriz Extracelular , Proteínas de Ligação a Ácido Graxo/metabolismo , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Invasividade Neoplásica , Motivos de Nucleotídeos , Neoplasias Gástricas/patologia
11.
Int J Mol Sci ; 21(11)2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32481541

RESUMO

Glucagon-like peptide-1 (GLP-1) is a well-known incretin hormone secreted from enteroendocrinal L cells in response to nutrients, such as glucose and dietary fat, and controls glycemic homeostasis. However, the detailed intracellular mechanisms of how L cells control GLP-1 secretion in response to nutrients still remain unclear. Here, we report that bone morphogenetic protein (BMP) signaling pathway plays a pivotal role to control GLP-1 secretion in response to nutrient replenishment in well-established mouse enteroendocrinal L cells (GLUTag cells). Nutrient starvation dramatically reduced cellular respiration and GLP-1 secretion in GLUTag cells. Transcriptome analysis revealed that nutrient starvation remarkably reduced gene expressions involved in BMP signaling pathway, whereas nutrient replenishment rescued BMP signaling to potentiate GLP-1 secretion. Transient knockdown of inhibitor of DNA binding (ID)1, a well-known target gene of BMP signaling, remarkably reduced GLP-1 secretion. Consistently, LDN193189, an inhibitor of BMP signaling, markedly reduced GLP-1 secretion in L cells. In contrast, BMP4 treatment activated BMP signaling pathway and potentiated GLP-1 secretion in response to nutrient replenishment. Altogether, we demonstrated that BMP signaling pathway is a novel molecular mechanism to control GLP-1 secretion in response to cellular nutrient status. Selective activation of BMP signaling would be a potent therapeutic strategy to stimulate GLP-1 secretion in order to restore glycemic homeostasis.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Incretinas/metabolismo , Proteína 1 Inibidora de Diferenciação/metabolismo , Transdução de Sinais , Animais , Glicemia/metabolismo , Linhagem Celular , Células Enteroendócrinas/metabolismo , Polipeptídeo Inibidor Gástrico/metabolismo , Regulação da Expressão Gênica , Homeostase , Insulina/metabolismo , Camundongos , Mitocôndrias/metabolismo , Nutrientes/metabolismo , Consumo de Oxigênio , Pirazóis/farmacologia , Pirimidinas/farmacologia , RNA Interferente Pequeno/metabolismo
12.
Int J Mol Sci ; 21(5)2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32111094

RESUMO

Gemcitabine is clinically used to treat certain types of cancers, including pancreatic and biliary cancer. We investigated the signal transduction pathways underlying the local antitumor effects of gemcitabine-eluting membranes (GEMs) implanted in pancreatic/biliary tumor-bearing nude mice. Here, we report that GEMs increased the E3 ubiquitin ligase c-CBL protein level, leading to degradation of epidermal growth factor receptor (EGFR) in SCK and PANC-1 cells. GEMs decreased the RAS and PI3K protein levels, leading to a reduction in the protein levels of active forms of downstream signaling molecules, including PDK, AKT, and GSK3ß. GEM reduced proliferation of cancer cells by upregulating cell cycle arrest proteins, particularly p53 and p21, and downregulating cyclin D1 and cyclin B. Moreover, GEMs reduced the levels of proangiogenic factors, including VEGF, VEGFR2, CD31, and HIF-1α, and inhibited tumor cell migration and invasion by inducing the expression of E-cadherin and reducing that of N-cadherin, snail, and vimentin. We demonstrated that local delivery of gemcitabine using GEM implants inhibited tumor cell growth by promoting c-CBL-mediated degradation of EGFR and inhibiting the proliferation, angiogenesis, and epithelial-mesenchymal transition of pancreatic/biliary tumors. Use of gemcitabine-eluting stents can improve stent patency by inhibiting the ingrowth of malignant biliary obstructions.


Assuntos
Colangiocarcinoma/tratamento farmacológico , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Receptores ErbB/metabolismo , Pâncreas/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Animais , Antígenos CD , Caderinas/metabolismo , Ciclo Celular , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células , Colangiocarcinoma/metabolismo , Colangiocarcinoma/patologia , Ciclina B/metabolismo , Ciclina D1/metabolismo , Desoxicitidina/uso terapêutico , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Camundongos Nus , Neoplasias Pancreáticas/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ubiquitina-Proteína Ligases/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Gencitabina
13.
Amino Acids ; 51(2): 245-254, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30255260

RESUMO

This study was conducted to evaluate the anti-obesity effects of long-term taurine supplementation in a mild obese ICR mouse model and to study the mechanism by which taurine induces weight loss. Three groups of male ICR mice were fed a normal chow diet, a high-fat diet (HFD), or an HFD supplemented with 2% taurine in drinking water for 28 weeks. Body weight was measured every week. Metabolic, behavioral, and physiological monitoring were carried out using PhenoMaster at 28 weeks. Interscapular brown fat (BAT), inguinal white fat tissue (WAT), and quadriceps muscle were analyzed and compared to assess the change of gene expression related to adipogenesis. Taurine supplementation showed the trend of anti-obesity effect in ICR mice fed an HFD for 28 weeks. HFD-fed mice did not show significant difference of oxygen consumption (VO2), energy expenditure (EE), respiratory exchange rate (RER), and locomotive activity compared with those of normal chow diet fed mice. The expression of adipogenesis-related genes such as PPAR-α, PPAR-γ, C/EBP-α, C/EBP-ß, and AP2 increased in BAT and WAT, but not in muscle tissue. Taurine supplementation showed the downregulation of these genes in WAT but not in BAT or muscle. Consistently, the expression of taurine transporter (TauT) and adipocyte-specific genes such as adiponectin, leptin, and IL-6 was regulated in a similar pattern by taurine supplementation. Long-term taurine supplementation causes weight loss, most likely by inhibiting adipogenesis in WAT. TauT expression may be involved in the expression of various genes regulated by taurine supplementation.


Assuntos
Adipogenia/efeitos dos fármacos , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Branco/efeitos dos fármacos , Fármacos Antiobesidade/uso terapêutico , Suplementos Nutricionais , Obesidade/dietoterapia , Taurina/uso terapêutico , Adipogenia/genética , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Fármacos Antiobesidade/farmacologia , Dieta Hiperlipídica , Metabolismo Energético/efeitos dos fármacos , Regulação da Expressão Gênica , Masculino , Glicoproteínas de Membrana/genética , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos ICR , Camundongos Obesos , Obesidade/metabolismo , Taurina/farmacologia , Fatores de Transcrição/genética , Redução de Peso/efeitos dos fármacos
14.
Hepatology ; 62(1): 220-31, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25545350

RESUMO

UNLABELLED: Bile acids (BAs) function as endocrine signaling molecules that activate multiple nuclear and membrane receptor signaling pathways to control fed-state metabolism. Since the detergent-like property of BAs causes liver damage at high concentrations, hepatic BA levels must be tightly regulated. Bile acid homeostasis is regulated largely at the level of transcription by nuclear receptors, particularly the primary BA receptor, farnesoid X receptor, and small heterodimer partner, which inhibits BA synthesis by recruiting repressive histone-modifying enzymes. Although histone modifiers have been shown to regulate BA-responsive genes, their in vivo functions remain unclear. Here, we show that lysine-specific histone demethylase1 (LSD1) is directly induced by BA-activated farnesoid X receptor, is recruited to the BA synthetic genes Cyp7a1 and Cyp8b1 and the BA uptake transporter gene Ntcp, and removes a gene-activation marker, trimethylated histone H3 lysine-4, leading to gene repression. Recruitment of LSD1 was dependent on small heterodimer partner, and LSD1-mediated demethylation of trimethylated histone H3 lysine-4 was required for additional repressive histone modifications, acetylated histone 3 on lysine 9 and 14 deacetylation, and acetylated histone 3 on lysine 9 methylation. A BA overload, feeding 0.5% cholic acid chow for 6 days, resulted in adaptive responses of altered expression of hepatic genes involved in BA synthesis, transport, and detoxification/conjugation. In contrast, adenovirus-mediated downregulation of hepatic LSD1 blunted these responses, which led to substantial increases in liver and serum BA levels, serum alanine aminotransferase and aspartate aminotransferase levels, and hepatic inflammation. CONCLUSION: This study identifies LSD1 as a novel histone-modifying enzyme in the orchestrated regulation mediated by the farnesoid X receptor and small heterodimer partner that reduces hepatic BA levels and protects the liver against BA toxicity.


Assuntos
Ácidos e Sais Biliares/metabolismo , Regulação da Expressão Gênica , Histona Desmetilases/metabolismo , Fígado/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Epigênese Genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout
16.
Proc Natl Acad Sci U S A ; 108(8): 3412-7, 2011 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-21300871

RESUMO

The ligand-dependent competing actions of nuclear receptor (NR)-associated transcriptional corepressor and coactivator complexes allow for the precise regulation of NR-dependent gene expression in response to both temporal and environmental cues. Here we report the mouse model termed silencing mediator of retinoid and thyroid hormone receptors (SMRT)(mRID1) in which targeted disruption of the first receptor interaction domain (RID) of the nuclear corepressor SMRT disrupts interactions with a subset of NRs and leads to diet-induced superobesity associated with a depressed respiratory exchange ratio, decreased ambulatory activity, and insulin resistance. Although apparently normal when chow fed, SMRT(mRID1) mice develop multiple metabolic dysfunctions when challenged by a high-fat diet, manifested by marked lipid accumulation in white and brown adipose tissue and the liver. The increased weight gain of SMRT(mRID1) mice on a high-fat diet occurs predominantly in fat with adipocyte hypertrophy evident in both visceral and s.c. depots. Importantly, increased inflammatory gene expression was detected only in the visceral depots. SMRT(mRID1) mice are both insulin-insensitive and refractory to the glucose-lowering effects of TZD and AICAR. Increased serum cholesterol and triglyceride levels were observed, accompanied by increased leptin and decreased adiponectin levels. Aberrant storage of lipids in the liver occurred as triglycerides and cholesterol significantly compromised hepatic function. Lipid accumulation in brown adipose tissue was associated with reduced thermogenic capacity and mitochondrial biogenesis. Collectively, these studies highlight the essential role of NR corepressors in maintaining metabolic homeostasis and describe an essential role for SMRT in regulating the progression, severity, and therapeutic outcome of metabolic diseases.


Assuntos
Tecido Adiposo/metabolismo , Dieta/efeitos adversos , Resistência à Insulina , Correpressor 2 de Receptor Nuclear/fisiologia , Obesidade/etiologia , Fosforilação Oxidativa , Animais , Homeostase , Metabolismo dos Lipídeos , Fígado/metabolismo , Camundongos
17.
Exp Mol Med ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38945960

RESUMO

Serine is a key contributor to the generation of one-carbon units for DNA synthesis during cellular proliferation. In addition, it plays a crucial role in the production of antioxidants that prevent abnormal proliferation and stress in cancer cells. In recent studies, the relationship between cancer metabolism and the serine biosynthesis pathway has been highlighted. In this context, 3-phosphoglycerate dehydrogenase (PHGDH) is notable as a key enzyme that functions as the primary rate-limiting enzyme in the serine biosynthesis pathway, facilitating the conversion of 3-phosphoglycerate to 3-phosphohydroxypyruvate. Elevated PHGDH activity in diverse cancer cells is mediated through genetic amplification, posttranslational modification, increased transcription, and allosteric regulation. Ultimately, these characteristics allow PHGDH to not only influence the growth and progression of cancer but also play an important role in metastasis and drug resistance. Consequently, PHGDH has emerged as a crucial focal point in cancer research. In this review, the structural aspects of PHGDH and its involvement in one-carbon metabolism are investigated, and PHGDH is proposed as a potential therapeutic target in diverse cancers. By elucidating how PHGDH expression promotes cancer growth, the goal of this review is to provide insight into innovative treatment strategies. This paper aims to reveal how PHGDH inhibitors can overcome resistance mechanisms, contributing to the development of effective cancer treatments.

18.
Diabetes Metab J ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38644620

RESUMO

Background: Diacylglycerol O-acyltransferase 2 (DGAT2) synthesizes triacylglycerol (TG) from diacylglycerol; therefore, DGAT2 is considered as a therapeutic target for steatosis. However, the consequence of inhibiting DGAT2 is not fully investigated due to side effects including lethality and lipotoxicity. In this article, we observed the role of DGAT2 in hepatocarcinoma. Methods: The role of DGAT2 is analyzed via loss-of-function assay. DGAT2 knockdown (KD) and inhibitor treatment on HepG2 cell line was analyzed. Cumulative analysis of cell metabolism with bioinformatic data were assessed, and further compared with different cohorts of liver cancer patients and non-alcoholic fatty liver disease (NAFLD) patients to elucidate how DGAT2 is regulating cancer metabolism. Results: Mitochondrial function is suppressed in DGAT2 KD HepG2 cell along with the decreased lipid droplets. In the aspect of the cancer, DGAT2 KD upregulates cell proliferation. Analyzing transcriptome of NAFLD and hepatocellular carcinoma (HCC) patients highlights negatively correlating expression patterns of 73 lipid-associated genes including DGAT2. Cancer patients with the lower DGAT2 expression face lower survival rate. DGAT2 KD cell and patients' transcriptome show downregulation in estrogen- related receptor alpha (ESRRA) via integrated system for motif activity response analysis (ISMARA), with increased dimerization with corepressor prospero homeobox 1 (PROX1). Conclusion: DGAT2 sustains the stability of mitochondria in hepatoma via suppressing ESRRA-PROX1 transcriptional network and hinders HCC from shifting towards glycolytic metabolism, which lowers cell proliferation.

19.
Cell Death Discov ; 10(1): 5, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38182557

RESUMO

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with inferior outcomes owing to its low treatment response and high invasiveness. Based on abundant cancer-associated fibroblasts (CAFs) and frequent mutation of breast cancer-associated 1 (BRCA1) in TNBC, the characteristics of CAFs in TNBC patients with BRCA1 mutation compared to wild-type were investigated using single-cell analysis. Intriguingly, we observed that characteristics of inflammatory CAFs (iCAFs) were enriched in patients with BRCA1 mutation compared to the wild-type. iCAFs in patients with BRCA1 mutation exhibited outgoing signals to endothelial cells (ECs) clusters, including chemokine (C-X-C motif) ligand (CXCL) and vascular endothelial growth factor (VEGF). During CXCL signaling, the atypical chemokine receptor 1 (ACKR1) mainly interacts with CXCL family members in tumor endothelial cells (TECs). ACKR1-high TECs also showed high expression levels of angiogenesis-related genes, such as ANGPT2, MMP1, and SELE, which might lead to EC migration. Furthermore, iCAFs showed VEGF signals for FLT1 and KDR in TECs, which showed high co-expression with tip cell marker genes, including ZEB1 and MAFF, involved in sprouting angiogenesis. Moreover, BRCA1 mutation patients with relatively abundant iCAFs and tip cell gene expression exhibited a limited response to neoadjuvant chemotherapy, including cisplatin and bevacizumab. Importantly, our study observed the intricate link between iCAFs-mediated angiogenesis and chemoresistance in TNBC with BRCA1 mutation.

20.
BMB Rep ; 57(4): 200-205, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38523372

RESUMO

We conducted a comprehensive series of molecular biological studies aimed at unraveling the intricate mechanisms underlying the anti-fibrotic effects of triamcinolone acetonide (TA) when used in conjunction with fully covered self-expandable metal stents (FCSEMS) for the management of benign biliary strictures (BBS). To decipher the molecular mechanisms responsible for the anti-fibrotic effects of corticosteroids on gallbladder mucosa, we conducted a comprehensive analysis. This analysis included various methodologies such as immunohistochemistry, ELISA, real-time PCR, and transcriptome analysis, enabling us to examine alterations in factors related to fibrosis and inflammation at both the protein and RNA levels. Overall, our findings revealed a dose-dependent decrease in fibrosisrelated signaling with higher TA concentrations. The 15 mg of steroid treatment (1X) exhibited anti-fibrosis and anti-inflammatory effects after 4 weeks, whereas the 30 mg of steroid treatment (2X) rapidly reduced fibrosis and inflammation within 2 weeks in BBS. Transcriptomic analysis results consistently demonstrated significant downregulation of fibrosis- and inflammation-related pathways and genes in steroid-treated fibroblasts. Use of corticosteroids, specifically TA, together with FCSEMS was effective for the treatment of BBS, ameliorating fibrosis and inflammation. Our molecular biological analysis supports the potential development of steroid-eluted FCSEMS as a therapeutic option for BBS in humans resulting from various surgical procedures. [BMB Reports 2024; 57(4): 200-205].


Assuntos
Fibrose , Inflamação , Triancinolona Acetonida , Triancinolona Acetonida/farmacologia , Triancinolona Acetonida/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/patologia , Humanos , Animais , Constrição Patológica/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Masculino , Stents
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