RESUMO
Dysbiosis has been implicated in childhood obesity. Oral intake of fermented milk containing Lacticaseibacillus casei strain Shirota preserves gut microbiota (GM) diversity in children and adults. This study was a double-blind trial involving 37 overweight or obese children aged 6-10 years. Children were followed over a 6-week intervention period in which they received different fermented milk products containing L. casei Shirota: 10 in the first group received just L. casei Shirota; 13 received L. casei Shirota with 3 g/day of inulin (L. casei+inulin); and 14 received L. casei Shirota with 3 g/day of fructans from Agave salmiana (L. casei+fructans). Principal component analysis showed the relationship between microbial abundance, GM metabolites, and other obesity-related markers. Supplementation with probiotics and synbiotics improved the HDL-cholesterol levels of overweight and obese children, although no changes in body composition were detected. We observed an increase in butyrate or propionate concentrations in the L. casei+fructans group compared to the end of the intervention (P<0.03). A diminished level of ANGPTL4 within the L. casei+fructans group (P=0.04) was also found, but no differences when lipopolysaccharide-binding protein was evaluated. The FFAR2+ cell frequency decreased between baseline and at the end of 6-week intervention in L. casei+inulin (P=0.02) and L. casei+fructans groups (P=0.04). In contrast, the percentage of CD14+FFAR3+ frequency increased in the same groups (P=0.04). The L. casei Shirota with inulin or fructans modulates GM, which improves the lipid profile and changes at a molecular level, such as expression of FFAR3 and FFAR2, ANGPTL4, propionate, and butyrate. It, therefore, could be considered an interesting therapeutic possibility for treating childhood overweight and obesity. The study was registered at ClinicalTrials.gov (ID: NCT05423015).
Assuntos
Agave , Produtos Fermentados do Leite , Obesidade Infantil , Probióticos , Criança , Adulto , Humanos , Frutanos , Agave/química , Inulina/farmacologia , Sobrepeso/tratamento farmacológico , Obesidade Infantil/tratamento farmacológico , Propionatos , BiomarcadoresRESUMO
Abstract This study aimed to investigate the acute effects of oleic acid (OA) on glucose homeostasis in mice fed a standard chow diet (SCD) and a high-fructose, high-fat diet (HFrHFD); moreover, the role of free fatty acid receptor 1 (FFAR1) was evaluated. The mice in the two groups were further divided into three subgroups as follows: control, OA (40 mg/kg), and OA + GW1100 (0.4 mg/kg, selective FFAR1 blocker). After a 16-week feeding period, the mice received the drugs via intraperitoneal (i.p.) injection followed by an i.p. glucose tolerance test (IPGTT) 30 min later. After 3 days, the mice received the same drugs to examine the effects of the drugs on the hepatic levels of phosphatidylinositol-4,5-bisphosphate (PIP2) and diacylglycerol (DAG). OA in the SCD-fed mice significantly increased the blood glucose level (48%, P < 0.001) after 30 min of glucose load compared to that in the control group, but did not affect the levels of PIP2 and DAG. Pre-injection with GW1100 significantly decreased the area under the curve of the IPGTT (28%, P < 0.05) in the SCD group compared to that in the SCD + OA group. OA reduced the blood glucose level (35%, P < 0.001) after 120 min of glucose load in the HFrHFD-fed mice; in addition, it increased hepatic PIP2 (160%, P < 0.01) and decreased hepatic DAG (60%, P < 0.001) levels. Pre-injection with GW1100 blocked the effects of OA on hepatic PIP2 and DAG without affecting the glucose tolerance. In conclusion, OA acutely impaired the glucose tolerance in the SCD-fed mice by acting on FFAR1 but did not improve it in the HFrHFD-fed mice.
RESUMO
Short-chain fatty acids (SCFAs) are the main metabolites produced by the bacterial fermentation of dietary fiber, and they play a critical role in the maintenance of intestinal health. SCFAs are also essential for modulating different processes, and they have anti-inflammatory properties and immunomodulatory effects. As the inflammatory process predisposes the development of cancer and promotes all stages of tumorigenesis, an antitumor effect has also been associated with SCFAs. This is strongly supported by epidemiological studies showing that a diet rich in fiber is linked to a reduced risk of colon cancer and has significant clinical benefits in patients with inflammatory bowel disease (IBD). SCFAs may signal through the metabolite-sensing G protein-coupled receptors free fatty acid receptor 3 [FFAR3 or G protein-coupled receptor 41 (GPR41)], FFAR2 (GPR43), and GPR109A (also known as hydroxycarboxylic acid receptor 2 or HCAR2) expressed in the gut epithelium and immune cells. This review summarizes the existing knowledge regarding the SCFA-mediated suppression of inflammation and carcinogenesis in IBD and colon cancer.
RESUMO
BACKGROUND: Free fatty acid receptor 1 (FFAR1) is G-protein coupled receptor predominantly expressed in pancreatic ß-cells that is activated by a variety of free fatty acids (FFAs). Once activated, it promotes glucose-stimulated insulin secretion (GSIS). However, increased levels of FFAs lead to lipotoxicity, inducing loss of ß-cell function. FFAR1 plays a key role in the development of type 2 diabetes (T2D), and previous studies have indicated the importance of developing anti-diabetic therapies against FFAR1, although its role in the regulation of ß-cell function remains unclear. The present study investigated the role of FFAR1 under lipotoxic conditions using palmitic acid (PA). The rat insulinoma 1 clone 832/13 (INS-1 832/13) cell line was used as a model as it physiologically resembles native pancreatic ß-cells. Key players of the insulin signaling pathway, such as mTOR, Akt, IRS-1, and the insulin receptor (INSR1ß), were selected as candidates to be analyzed under lipotoxic conditions. RESULTS: We revealed that PA-induced lipotoxicity affected GSIS in INS-1 cells and negatively modulated the activity of both IRS-1 and Akt. Reduced phosphorylation of both IRS-1 S636/639 and Akt S473 was observed, in addition to decreased expression of both INSR1ß and FFAR1. Moreover, transient knockdown of FFAR1 led to a reduction in IRS-1 mRNA expression and an increase in INSR1ß mRNA. Finally, PA affected localization of FFAR1 from the cytoplasm to the perinucleus. CONCLUSIONS: In conclusion, our study suggests a novel regulatory involvement of FFAR1 in crosstalk with mTOR-Akt and IRS-1 signaling in ß-cells under lipotoxic conditions.
Assuntos
Células Secretoras de Insulina/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Ácido Palmítico/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Apoptose , Linhagem Celular , Células Secretoras de Insulina/metabolismo , Ratos , Transdução de SinaisRESUMO
Short-chain fatty acids (SCFAs) exert a variety of immune and metabolic functions by binding to G-protein-coupled receptors, mainly free fatty acid receptor 2 (FFAR2). However, the effects of SCFAs and FFARs on bone remodeling, especially in alveolar bone, have been less explored. In this study, we investigated the influence of the SCFA/FFAR2 axis on alveolar bone. Bone samples from wild-type (WT) and FFAR2-deficient mice (FFAR2-/-) were analyzed using micro-CT, histology and qPCR. WT and FFAR2-/- animals received a high-fiber diet (HFD) reported to increase circulating levels of SCFAs. Additionally, we analyzed the effects of SCFAs and a synthetic FFAR2 agonist, phenylacetamide-1 (CTMB), on bone cell differentiation. The participation of histone deacetylase inhibitors (iHDACs) in the effects of SCFAs was further assessed in vitro. CTMB treatment was also evaluated in vivo during orthodontic tooth movement (OTM). FFAR2-/- mice exhibited deterioration of maxillary bone parameters. Consistent with this, FFAR2-/- mice exhibited a significant increase of OTM and changes in bone cell numbers and in the expression of remodeling markers. The HFD partially reversed bone loss in the maxillae of FFAR2-/- mice. In WT mice, the HFD induced changes in the bone markers apparently favoring a bone formation scenario. In vitro, bone marrow cells from FFAR2-/- mice exhibited increased differentiation into osteoclasts, while no changes in osteoblasts were observed. In line with this, differentiation of osteoclasts was diminished by SCFAs and CTMB. Moreover, CTMB treatment significantly reduced OTM. Pretreatment of osteoclasts with iHDACs did not modify the effects of SCFAs on these cells. In conclusion, SCFAs function as regulators of bone resorption. The effects of SCFAs on osteoclasts are dependent on FFAR2 activation and are independent of the inhibition of HDACs. FFAR2 agonists may be useful to control bone osteolysis.
Assuntos
Ácidos Graxos Voláteis/farmacologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Reabsorção Óssea/tratamento farmacológico , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Receptores Acoplados a Proteínas G/genética , Microtomografia por Raio-XRESUMO
Linoleic acid (LA) is an essential and omega-6 polyunsaturated fatty acid that mediates a variety of biological processes, including migration and invasion in breast cancer cells. Phospholipase D (PLD) catalyses the hydrolysis of phosphatidylcholine to produce phosphatidic acid and choline. Increases of expression and activity of PLD are reported in several human cancers, including gastric, colorectal, renal, stomach, lung and breast. In this article, we demonstrate that LA induces an increase of PLD activity in MDA-MB-231 breast cancer cells. Particularly, PLD1 and/or PLD2 mediate migration and invasion induced by LA. Moreover, LA induces increases in number and size of spheroids via PLD activity. FFAR1 also mediates migration and invasion, whereas PLD activation induced by LA requires the activities of FFAR1, FFAR4 and EGFR in MDA-MB-231 cells. In summary, PLD plays a pivotal role in migration and invasion induced by LA in MDA-MB-231 breast cancer cells.
Assuntos
Neoplasias da Mama/enzimologia , Movimento Celular/efeitos dos fármacos , Ácido Linoleico/farmacologia , Proteínas de Neoplasias/metabolismo , Fosfolipase D/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos , Células MCF-7 , Invasividade NeoplásicaRESUMO
BACKGROUND: Free fatty acid receptor 1 (FFAR1) is G-protein coupled receptor predominantly expressed in pancreatic ß-cells that is activated by a variety of free fatty acids (FFAs). Once activated, it promotes glucose-stimulated insulin secretion (GSIS). However, increased levels of FFAs lead to lipotoxicity, inducing loss of ß-cell function. FFAR1 plays a key role in the development of type 2 diabetes (T2D), and previous studies have indicated the importance of developing anti-diabetic therapies against FFAR1, although its role in the regulation of ß-cell function remains unclear. The present study investigated the role of FFAR1 under lipotoxic conditions using palmitic acid (PA). The rat insulinoma 1 clone 832/13 (INS-1 832/13) cell line was used as a model as it physiologically resembles native pancreatic ß-cells. Key players of the insulin signaling pathway, such as mTOR, Akt, IRS-1, and the insulin receptor (INSR1ß), were selected as candidates to be analyzed under lipotoxic conditions. RESULTS: We revealed that PA-induced lipotoxicity affected GSIS in INS-1 cells and negatively modulated the activity of both IRS-1 and Akt. Reduced phosphorylation of both IRS-1 S636/639 and Akt S473 was observed, in addition to decreased expression of both INSR1ß and FFAR1. Moreover, transient knockdown of FFAR1 led to a reduction in IRS-1 mRNA expression and an increase in INSR1ß; mRNA. Finally, PA affected localization of FFAR1 from the cytoplasm to the perinucleus. CONCLUSIONS: In conclusion, our study suggests a novel regulatory involvement of FFAR1 in crosstalk with mTOR-Akt and IRS-1 signaling in ß-cells under lipotoxic conditions.
Assuntos
Animais , Ratos , Ácido Palmítico/toxicidade , Receptores Acoplados a Proteínas G/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Transdução de Sinais , Linhagem Celular , Apoptose , Células Secretoras de Insulina/metabolismoRESUMO
An increased risk of developing breast cancer has been associated with high levels of dietary fat intake. Linoleic acid (LA) is an essential fatty acid and the major ω-6 polyunsaturated fatty acid in occidental diets, which is able to induce inappropriate inflammatory responses that contribute to several chronic diseases including cancer. In breast cancer cells, LA induces migration. However, the signal transduction pathways that mediate migration and whether LA induces invasion in MDA-MB-231 breast cancer cells have not been studied in detail. We demonstrate here that LA induces Akt2 activation, invasion, an increase in NFκB-DNA binding activity, miR34a upregulation and miR9 downregulation in MDA-MB-231 cells. Moreover, Akt2 activation requires EGFR and PI3K activity, whereas migration and invasion are dependent on FFAR4, EGFR and PI3K/Akt activity. Our findings demonstrate, for the first time, that LA induces migration and invasion through an EGFR-/PI3K-/Akt-dependent pathway in MDA-MB-231 breast cancer cells.
Assuntos
Neoplasias da Mama/metabolismo , Movimento Celular/efeitos dos fármacos , Ácido Linoleico/farmacologia , Invasividade Neoplásica/fisiopatologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Transdução de Sinais/efeitos dos fármacosRESUMO
Fatty acids have been recognized as regulators of immune function in addition to their known metabolic role. Long-chain fatty acids bind free fatty acid receptor (FFAR)-1/GPR40, which is expressed on bovine neutrophils, and increase responses such as granule release and gene expression. In this study, we investigated the molecular mechanisms governing the up-regulation of cyclooxygenase-2 (COX-2) and IL-8, as well as matrix metalloproteinase (MMP)-9 granule release in FFAR1/GPR40 agonist-stimulated neutrophils. Our results showed that natural (oleic and linoleic acid) and synthetic (GW9508) FFAR1/GPR40 agonists increased ERK1/2, p38 MAPK and Akt phosphorylation, and that the FFAR1/GPR40 antagonist GW1100 reduced these responses. We evaluated the levels of IκBα, a component of the classical activation pathway of the transcription factor NF-κB, and we observed IκBα reduction after stimulation with FFAR1/GPR40 agonists, an effect that was inhibited by GW1100 or the inhibitors UO126, SB203580 or LY294002. FFAR1/GPR40 agonists increased COX-2 and IL-8 expression, which was inhibited by GW1100 and an NF-κB inhibitor. Finally, the FFAR1/GPR40 agonist-induced MMP-9 granule release was reduced by GW1100 and UO126. In conclusion, FFAR1/GPR40 agonists differentially stimulate neutrophil functions; COX-2 and IL-8 are expressed after FFAR1/GPR40 activation via NF-κB, IκBα reduction is FFAR1/GPR40- and PI3K/MAPK-dependent, and MMP-9 granule release is FFAR1/GPR40- and ERK1/2-dependent.