RESUMO
Cells are separated from the environment by a lipid bilayer membrane that is relatively impermeable to solutes. The transport of ions and small molecules across this membrane is an essential process in cell biology and metabolism. Monocarboxylate transporters (MCTs) belong to a vast family of solute carriers (SLCs) that facilitate the transport of certain hydrophylic small compounds through the bilipid cell membrane. The existence of 446 genes that code for SLCs is the best evidence of their importance. In-depth research on MCTs is quite recent and probably promoted by their role in cancer development and progression. Importantly, it has recently been realized that these transporters represent an interesting target for cancer treatment. The search for clinically useful monocarboxylate inhibitors is an even more recent field. There is limited pre-clinical and clinical experience with new inhibitors and their precise mechanism of action is still under investigation. What is common to all of them is the inhibition of lactate transport. This review discusses the structure and function of MCTs, their participation in cancer, and old and newly developed inhibitors. Some suggestions on how to improve their anticancer effects are also discussed.
RESUMO
BACKGROUND: The metabolic reprogramming of mesenchymal stem/stromal cells (MSC) favoring glycolysis has recently emerged as a new approach to improve their immunotherapeutic abilities. This strategy is associated with greater lactate release, and interestingly, recent studies have proposed lactate as a functional suppressive molecule, changing the old paradigm of lactate as a waste product. Therefore, we evaluated the role of lactate as an alternative mediator of MSC immunosuppressive properties and its contribution to the enhanced immunoregulatory activity of glycolytic MSCs. MATERIALS AND METHODS: Murine CD4+ T cells from C57BL/6 male mice were differentiated into proinflammatory Th1 or Th17 cells and cultured with either L-lactate, MSCs pretreated or not with the glycolytic inductor, oligomycin, and MSCs pretreated or not with a chemical inhibitor of lactate dehydrogenase A (LDHA), galloflavin or LDH siRNA to prevent lactate production. Additionally, we validated our results using human umbilical cord-derived MSCs (UC-MSCs) in a murine model of delayed type 1 hypersensitivity (DTH). RESULTS: Our results showed that 50 mM of exogenous L-lactate inhibited the proliferation rate and phenotype of CD4+ T cell-derived Th1 or Th17 by 40% and 60%, respectively. Moreover, the suppressive activity of both glycolytic and basal MSCs was impaired when LDH activity was reduced. Likewise, in the DTH inflammation model, lactate production was required for MSC anti-inflammatory activity. This lactate dependent-immunosuppressive mechanism was confirmed in UC-MSCs through the inhibition of LDH, which significantly decreased their capacity to control proliferation of activated CD4+ and CD8+ human T cells by 30%. CONCLUSION: These findings identify a new MSC immunosuppressive pathway that is independent of the classical suppressive mechanism and demonstrated that the enhanced suppressive and therapeutic abilities of glycolytic MSCs depend at least in part on lactate production.
Assuntos
Ácido Láctico , Células-Tronco Mesenquimais , Humanos , Masculino , Animais , Camundongos , Camundongos Endogâmicos C57BL , Imunossupressores , Diferenciação CelularRESUMO
This study examined the effect of caffeine supplementation (CAFF) in a Wingate test (WT), and the behaviour of blood lactate concentrations (BLa) and neuromuscular fatigue (NMF), measured as reduced countermovement jump (CMJ) performance, in response to the WT. In a double-blind crossover study, 16 participants attended the laboratory twice, separated by a 72-hour window. In the sessions, participants first ingested 6 mg·kg-1 of either CAFF or placebo (PLAC), and then performed a WT. BLa was measured before (L-pre), and 0.5 min (L-post-0.5) and 3.5 min (L-post-3.5) after conducting the WT. The CMJ test was conducted before (CMJ pre), after (CMJ post), and 3 min after completing (CMJ post-3) the WT. The results indicated that CAFF enhanced peak power (Wpeak: + 3.22%; p = 0.040), time taken to reach Wpeak (T_Wpeak: -18.76%; p = 0.001) and mean power (Wmean: + 2.7%; p = 0.020). A higher BLa was recorded for CAFF at L-post-0.5 (+ 13.29%; p = 0.009) and L-post-3.5 (+ 10.51%; p = 0.044) compared to PLAC. CAFF improved peak power (PP; + 3.44%; p = 0.003) and mean power (MP; + 4.78%; p = 0.006) at CMJ pre, compared to PLAC, whereas PP and MP were significantly diminished at CMJ post and CMJ post-3 compared to pre (p < 0.001 for all comparisons) under both the CAFF and PLAC conditions. PP and MP were increased at post-3 compared to post (p < 0.001 for all comparisons) for both conditions. In conclusion, CAFF increased WT performance and BLa without affecting NMF measured by CMJ. Thus, CAFF may allow athletes to train with higher workloads and enhance the supercompensation effects after an adequate recovery period.
RESUMO
INTRODUCTION: Cancer of unknown primary origin (CUP) is defined as metastatic cancer without identification of the primary site. Considering that only 15-20% of patients with CUP show a favorable outcome, identifying biomarkers may help improve the clinical management of patients who do not respond well to conventional therapies. In this context, the study of the metabolic profile of CUP may pave the way to establish new biomarkers and/or therapeutic targets; therefore, this study aimed to characterize the expression of metabolism-related proteins in CUP. MATERIALS AND METHODS: The expression of monocarboxylate transporters MCT1, MCT2 and MCT4, their chaperone CD147, the glucose transporter GLUT1 and the pH regulator CAIX was evaluated by immunohistochemistry in a series of 118 CUP patients, and the results were associated with the available clinicopathological information. RESULTS: The metabolism-related proteins MCT1, MCT4, CD147, GLUT1 and CAIX were expressed in a critical portion of the CUP (approximately 20 to 70%). MCT1 and CD147 were both more frequently expressed in cases with lymph nodes as metastasis dominant sites (p = 0.001) as well as in samples from lymph nodes (p <0.001 and p = 0.002, respectively), while MCT1 expression was more frequently expressed in squamous cell carcinomas (p = 0.045). A higher overall survival was observed in patients with tumors positive for GLUT1 and CAIX expression (p = 0.011 and p = 0.041, respectively), but none of the proteins was an independent prognostic factor for overall survival in multivariable analysis. CONCLUSION: The results suggest that a portion of CUPs present a hyperglycolytic phenotype, which is associated with higher overall survival.
RESUMO
Objectives: Mesenchymal Stem/Stromal Cells (MSC) are promising therapeutic tools for inflammatory diseases due to their potent immunoregulatory capacities. Their suppressive activity mainly depends on inflammatory cues that have been recently associated with changes in MSC bioenergetic status towards a glycolytic metabolism. However, the molecular mechanisms behind this metabolic reprogramming and its impact on MSC therapeutic properties have not been investigated. Methods: Human and murine-derived MSC were metabolically reprogramed using pro-inflammatory cytokines, an inhibitor of ATP synthase (oligomycin), or 2-deoxy-D-glucose (2DG). The immunosuppressive activity of these cells was tested in vitro using co-culture experiments with pro-inflammatory T cells and in vivo with the Delayed-Type Hypersensitivity (DTH) and the Graph versus Host Disease (GVHD) murine models. Results: We found that the oligomycin-mediated pro-glycolytic switch of MSC significantly enhanced their immunosuppressive properties in vitro. Conversely, glycolysis inhibition using 2DG significantly reduced MSC immunoregulatory effects. Moreover, in vivo, MSC glycolytic reprogramming significantly increased their therapeutic benefit in the DTH and GVHD mouse models. Finally, we demonstrated that the MSC glycolytic switch effect partly depends on the activation of the AMPK signaling pathway. Conclusion: Altogether, our findings show that AMPK-dependent glycolytic reprogramming of MSC using an ATP synthase inhibitor contributes to their immunosuppressive and therapeutic functions, and suggest that pro-glycolytic drugs might be used to improve MSC-based therapy.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Glicólise/efeitos dos fármacos , Doença Enxerto-Hospedeiro/imunologia , Hipersensibilidade Tardia/imunologia , Células-Tronco Mesenquimais/efeitos dos fármacos , ATPases Mitocondriais Próton-Translocadoras/antagonistas & inibidores , Animais , Antimetabólitos/farmacologia , Linfócitos T CD4-Positivos , Desoxiglucose/farmacologia , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Humanos , Imunoterapia , Ácido Láctico/metabolismo , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/imunologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Oligomicinas/farmacologia , Fosforilação Oxidativa , Consumo de OxigênioRESUMO
The enzymatic complex Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase (NOx) may be the principal source of reactive oxygen species (ROS). The NOX2 and NOX4 isoforms are tissue-dependent and are differentially expressed in slow-twitch fibers (type I fibers) and fast-twitch fibers (type II fibers) of skeletal muscle, making them different markers of ROS metabolism induced by physical exercise. The aim of this study was to investigate NOx signaling, as a non-adaptive and non-cumulative response, in the predominant fiber types of rat skeletal muscles 24 h after one strenuous treadmill exercise session. The levels of mRNA, reduced glycogen, thiol content, NOx, superoxide dismutase, catalase, glutathione peroxidase activity, and PPARGC1α and SLC2A4 gene expression were measured in the white gastrocnemius (WG) portion, the red gastrocnemius (RG) portion, and the soleus muscle (SOL). NOx activity showed higher values in the SOL muscle compared to the RG and WG portions. The same was true of the NOX2 and NOX4 mRNA levels, antioxidant enzymatic activities, glycogen content. Twenty-four hours after the strenuous exercise session, NOx expression increased in slow-twitch oxidative fibers. The acute strenuous exercise condition showed an attenuation of oxidative stress and an upregulation of antioxidant activity through PPARGC1α gene activity, antioxidant defense adaptations, and differential gene expression according to the predominant fiber type. The most prominent location of detoxification (indicated by NOX4 activation) in the slow-twitch oxidative SOL muscle was the mitochondria, while the fast-twitch oxidative RG portion showed a more cytosolic location. Glycolytic metabolism in the WG portion suggested possible NOX2/NOX4 non-regulation, indicating other possible ROS regulation pathways.
RESUMO
BACKGROUND: Locally advanced breast cancer often undergoes neoadjuvant chemotherapy (NAC), which allows in vivo evaluation of the therapeutic response. The determination of the pathological complete response (pCR) is one way to evaluate the response to neoadjuvant chemotherapy. However, the rate of pCR differs significantly between molecular subtypes and the cause is not yet determined. Recently, the metabolic reprogramming of cancer cells and its implications for tumor growth and dissemination has gained increasing prominence and could contribute to a better understanding of NAC. Thus, this study proposed to evaluate the expression of metabolism-related proteins and its association with pCR and survival rates. METHODS: The expression of monocarboxylate transporters 1 and 4 (MCT1 and MCT4, respectively), cluster of differentiation 147 (CD147), glucose transporter-1 (GLUT1) and carbonic anhydrase IX (CAIX) was analyzed in 196 locally advanced breast cancer samples prior to NAC. The results were associated with clinical-pathological characteristics, occurrence of pCR, disease-free survival (DFS), disease-specific survival (DSS) and overall survival (OS). RESULTS: The occurrence of pCR was higher in the group of patients whith tumors expressing GLUT1 and CAIX than in the group without expression (27.8% versus 13.1%, p = 0.030 and 46.2% versus 13.5%, p = 0.007, respectively). Together with regional lymph nodes staging and mitotic staging, CAIX expression was considered an independent predictor of pCR. In addition, CAIX expression was associated with DFS and DSS (p = 0.005 and p = 0.012, respectively). CONCLUSIONS: CAIX expression was a predictor of pCR and was associated with higher DFS and DSS in locally advanced breast cancer patients subjected to NAC.
Assuntos
Antígenos de Neoplasias/biossíntese , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Anidrase Carbônica IX/biossíntese , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Biomarcadores Tumorais/biossíntese , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Transportador de Glucose Tipo 1/biossíntese , Glicólise , Humanos , Imuno-Histoquímica , Metástase Linfática , Pessoa de Meia-Idade , Transportadores de Ácidos Monocarboxílicos/biossíntese , Proteínas Musculares/biossíntese , Terapia Neoadjuvante , Estudos Retrospectivos , Taxa de Sobrevida , Simportadores/biossíntese , Resultado do TratamentoRESUMO
In chemoresistant leukemia cells (Lucena-1), the low molecular weight protein tyrosine phosphatase (LMWPTP) is about 20-fold more active than in their susceptible counterpart (K562). We found this phosphatase ensures the activated statuses of Src and Bcr-Abl. Since, phosphorylation and dephosphorylation of proteins represent a key post-translational regulation of several enzymes, we also explored the kinome. We hereby show that LMWPTP superactivation, together with kinome reprogramming, cooperate towards glucose addiction. Resistant leukemia cells present lower levels of oxidative metabolism, in part due to downexpression of the following mitochondrial proteins: pyruvate dehydrogenase subunit alpha 1, succinate dehydrogenase, and voltage-dependent anion channel. Those cells displayed higher expression levels of glucose transporter 1 and higher production of lactate. In addition, Lucena-1 siRNA LMWPTP cells showed lower expression levels of glucose transporter 1 and lower activity of lactate dehydrogenase. On the other hand, K562 cells overexpressing LMWPTP presented higher expression/activity of both proteins. In this study, we show that LMWPTP is a pivotal mediator of metabolic reprogramming that confers survival advantages to leukemia cells against death stimuli. J. Cell. Biochem. 118: 3846-3854, 2017. © 2017 Wiley Periodicals, Inc.
Assuntos
Resistencia a Medicamentos Antineoplásicos , Glicólise , Leucemia/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Transdução de Sinais , Doença Aguda , Humanos , Células K562 , Leucemia/patologia , FosforilaçãoRESUMO
Perception of color and its relationship to water holding capacity are important for defining the yield and quality of the pork production process. The aim of this study was to identify the relationship among color measurements taken at various anatomical positions in the cross-sectional surface of pork loin steak, and measurements of fluid exudation and its glucose concentration, as well as the impact on these attributes due to plasma glucose at slaughter. Two assays were conducted sequentially: i) investigation of the surface color parameters at different anatomical positions in the pork loin cross-section and their relationship to general exudation; and ii) the effect of plasma glucose levels on surface color variables, drip loss and glucose exudate concentration in three anatomical regions in the steak. The L* value of the ventro-lateral region, in the first assay, had the highest correlation with average steak drip loss at all anatomical points, exudation increasing proportionally between 48 and 72 h. The hue angle was also positively correlated with drip loss and lightness. The drip loss was greater when the animals had high plasma glucose, especially in the intermediate and lateral regions of the steak surface. The intermediate region presented greater lightness and lower redness. The plasma and glucose exudate concentrations, potential indicators of the muscle glycolytic metabolism, were related to color and drip loss. These variables can be influenced by the anatomical region inside the muscle, impacting the ability to retain water, two-toning occurrence and overall pork loin quality.
Assuntos
Carne/análise , Glucose/metabolismo , Qualidade dos Alimentos , SuínosRESUMO
Perception of color and its relationship to water holding capacity are important for defining the yield and quality of the pork production process. The aim of this study was to identify the relationship among color measurements taken at various anatomical positions in the cross-sectional surface of pork loin steak, and measurements of fluid exudation and its glucose concentration, as well as the impact on these attributes due to plasma glucose at slaughter. Two assays were conducted sequentially: i) investigation of the surface color parameters at different anatomical positions in the pork loin cross-section and their relationship to general exudation; and ii) the effect of plasma glucose levels on surface color variables, drip loss and glucose exudate concentration in three anatomical regions in the steak. The L* value of the ventro-lateral region, in the first assay, had the highest correlation with average steak drip loss at all anatomical points, exudation increasing proportionally between 48 and 72 h. The hue angle was also positively correlated with drip loss and lightness. The drip loss was greater when the animals had high plasma glucose, especially in the intermediate and lateral regions of the steak surface. The intermediate region presented greater lightness and lower redness. The plasma and glucose exudate concentrations, potential indicators of the muscle glycolytic metabolism, were related to color and drip loss. These variables can be influenced by the anatomical region inside the muscle, impacting the ability to retain water, two-toning occurrence and overall pork loin quality.(AU)