RESUMO

BACKGROUND: Aberrant gluconeogenesis is considered among primary drivers of hyperglycemia under insulin resistant conditions, with multiple studies pointing towards epigenetic dysregulation. Here we examine the role of miR-721 and effect of epigenetic modulator laccaic acid on the regulation of gluconeogenesis under high fat diet induced insulin resistance. RESULTS: Reanalysis of miRNA profiling data of high-fat diet-induced insulin-resistant mice model, GEO dataset (GSE94799) revealed a significant upregulation of miR-721, which was further validated in invivo insulin resistance in mice and invitro insulin resistance in Hepa 1-6 cells. Interestingly, miR-721 mimic increased glucose production in Hepa 1-6 cells via activation of FOXO1 regulated gluconeogenic program. Concomitantly, inhibition of miR-721 reduced glucose production in palmitate induced insulin resistant Hepa 1-6 cells by blunting the FOXO1 induced gluconeogenesis. Intriguingly, at epigenetic level, enrichment of the transcriptional activation mark H3K36me2 got decreased around the FOXO1 promoter. Additionally, identifying targets of miR-721 using miRDB.org showed H3K36me2 demethylase KDM2A as a potential target. Notably, miR-721 inhibitor enhanced KDM2A expression which correlated with H3K36me2 enrichment around FOXO1 promoter and the downstream activation of the gluconeogenic pathway. Furthermore, inhibition of miR-721 in high-fat diet-induced insulin-resistant mice resulted in restoration of KDM2A levels, concomitantly reducing FOXO1, PCK1, and G6PC expression, attenuating gluconeogenesis, hyperglycemia, and improving glucose tolerance. Interestingly, the epigenetic modulator laccaic acid also reduced the hepatic miR-721 expression and improved KDM2A expression, supporting our earlier report that laccaic acid attenuates insulin resistance by reducing gluconeogenesis. CONCLUSION: Our study unveils the role of miR-721 in regulating gluconeogenesis through KDM2A and FOXO1 under insulin resistance, pointing towards significant clinical and therapeutic implications for metabolic disorders. Moreover, the promising impact of laccaic acid highlights its potential as a valuable intervention in managing insulin resistance-associated metabolic diseases.

Assuntos

RESUMO

Doxorubicin (DOX), widely used as a chemotherapeutic agent for various cancers, is limited in its clinical utility by its cardiotoxic effects. Despite its widespread use, the precise mechanisms underlying DOX-induced cardiotoxicity at the cellular and molecular levels remain unclear, hindering the development of preventive and early detection strategies. To characterize the cytotoxic effects of DOX on isolated ventricular cardiomyocytes, focusing on the expression of specific microRNAs (miRNAs) and their molecular targets associated with endogenous cardioprotective mechanisms such as the ATP-sensitive potassium channel (KATP), Sirtuin 1 (SIRT1), FOXO1, and GSK3ß. We isolated Guinea pig ventricular cardiomyocytes by retrograde perfusion and enzymatic dissociation. We assessed cell morphology, Reactive Oxygen Species (ROS) levels, intracellular calcium, and mitochondrial membrane potential using light microscopy and specific probes. We determined the miRNA expression profile using small RNAseq and validated it using stem-loop qRT-PCR. We quantified mRNA levels of some predicted and validated molecular targets using qRT-PCR and analyzed protein expression using Western blot. Exposure to 10 µM DOX resulted in cardiomyocyte shortening, increased ROS and intracellular calcium levels, mitochondrial membrane potential depolarization, and changes in specific miRNA expression. Additionally, we observed the differential expression of KATP subunits (ABCC9, KCNJ8, and KCNJ11), FOXO1, SIRT1, and GSK3ß molecules associated with endogenous cardioprotective mechanisms. Supported by miRNA gene regulatory networks and functional enrichment analysis, these findings suggest that DOX-induced cardiotoxicity disrupts biological processes associated with cardioprotective mechanisms. Further research must clarify their specific molecular changes in DOX-induced cardiac dysfunction and investigate their diagnostic biomarkers and therapeutic potential.

Assuntos

RESUMO

Forkhead Box O1 (FOXO1) has been reported to play important roles in many tumors. However, FOXO1 has not been studied in pan-cancer. The purpose of this study was to reveal the roles of FOXO1 in pan-cancer (33 cancers in this study). Through multiple public platforms, a pan-cancer analysis of FOXO1 was conducted to obtained FOXO1 expression profiles in various tumors to explore the relationship between FOXO1 expression and prognosis of these tumors and to disclose the potential mechanism of FOXO1 in these tumors. FOXO1 was associated with the prognosis of multiple tumors, especially LGG (low grade glioma), OV (ovarian carcinoma), and KIRC (kidney renal clear cell carcinoma). FOXO1 might play the role of an oncogenic gene in LGG and OV, while playing the role of a cancer suppressor gene in KIRC. FOXO1 expression had a significant correlation with the infiltration of some immune cells in LGG, OV, and KIRC. By combining FOXO1 expression and immune cell infiltration, we found that FOXO1 might influence the overall survival of LGG through the infiltration of myeloid dendritic cells or CD4+ T cells. Functional enrichment analysis and gene set enrichment analysis showed that FOXO1 might play roles in tumors through immunoregulatory interactions between a lymphoid and a non-lymphoid cell, TGF-beta signaling pathway, and transcriptional misregulation in cancer. FOXO1 was associated with the prognosis of multiple tumors, especially LGG, OV, and KIRC. In these tumors, FOXO1 might play its role via the regulation of the immune microenvironment.

RESUMO

Background Aberrant gluconeogenesis is considered among primary drivers of hyperglycemia under insulin resistant conditions, with multiple studies pointing towards epigenetic dysregulation. Here we examine the role of miR-721 and effect of epigenetic modulator laccaic acid on the regulation of gluconeogenesis under high fat diet induced insulin resistance. Results Reanalysis of miRNA profiling data of high-fat diet-induced insulin-resistant mice model, GEO dataset (GSE94799) revealed a significant upregulation of miR-721, which was further validated in invivo insulin resistance in mice and invitro insulin resistance in Hepa 1-6 cells. Interestingly, miR-721 mimic increased glucose production in Hepa 1-6 cells via activation of FOXO1 regulated gluconeogenic program. Concomitantly, inhibition of miR-721 reduced glucose production in palmitate induced insulin resistant Hepa 1-6 cells by blunting the FOXO1 induced gluconeogenesis. Intriguingly, at epigenetic level, enrichment of the transcriptional activation mark H3K36me2 got decreased around the FOXO1 promoter. Additionally, identifying targets of miR-721 using miRDB.org showed H3K36me2 demethylase KDM2A as a potential target. Notably, miR-721 inhibitor enhanced KDM2A expression which correlated with H3K36me2 enrichment around FOXO1 promoter and the downstream activation of the gluconeogenic pathway. Furthermore, inhibition of miR-721 in high-fat diet-induced insulin-resistant mice resulted in restoration of KDM2A levels, concomitantly reducing FOXO1, PCK1, and G6PC expression, attenuating gluconeogenesis, hyperglycemia, and improving glucose tolerance. Interestingly, the epigenetic modulator laccaic acid also reduced the hepatic miR-721 expression and improved KDM2A expression, supporting our earlier report that laccaic acid attenuates insulin resistance by reducing gluconeogenesis. Conclusion Our study unveils the role of miR-721 in regulating gluconeogenesis through KDM2A and FOXO1 under insulin resistance, pointing towards significant clinical and therapeutic implications for metabolic disorders. Moreover, the promising impact of laccaic acid highlights its potential as a valuable intervention in managing insulin resistance-associated metabolic diseases.

RESUMO

Maternal diabetes is known to affect heart development, inducing the programming of cardiac alterations in the offspring's adult life. Previous studies in the heart of adult offspring have shown increased activation of FOXO1 (a transcription factor involved in a wide variety of cellular functions such as apoptosis, cellular proliferation, reactive oxygen species detoxification, and antioxidant and pro-inflammatory processes) and of target genes related to inflammatory and fibrotic processes. In this work, we aimed to evaluate the effects of maternal diabetes on FOXO1 activation as well as on the expression of target genes relevant to the formation of the cardiovascular system during organogenesis (day 12 of gestation). The embryonic heart from diabetic rats showed increased active FOXO1 levels, reduced protein levels of mTOR (a nutrient sensor regulating cell growth, proliferation and metabolism) and reduced mTORC2-SGK1 pathway, which phosphorylates FOXO1. These alterations were related to increases in the levels of 4-hydroxynonenal (an oxidative stress marker) and increased mRNA levels of inducible nitric oxide synthase, angiopoietin-2 and matrix metalloproteinase-2 (MMP2) (all FOXO1 target genes relevant for cardiac development). Results also showed increased extracellular and intracellular immunolocalization of MMP2 in the myocardium and its projection into the lumen of the cavity (trabeculations) together with decreased immunostaining of connexin 43, a protein relevant for cardiac function that is target of MMP2. In conclusion, increases in active FOXO1 induced by maternal diabetes initiate early during embryonic heart development and are related to increases in markers of oxidative stress and of proinflammatory cardiac development, as well to an altered expression of proteolytic enzymes that regulate connexin 43. These alterations may lead to an altered programming of cardiovascular development in the embryonic heart of diabetic rats.

Assuntos

RESUMO

Cardiac cells respond to various pathophysiological stimuli, synthesizing inflammatory molecules that allow tissue repair and proper functioning of the heart; however, perpetuation of the inflammatory response can lead to cardiac fibrosis and heart dysfunction. High concentration of glucose (HG) induces an inflammatory and fibrotic response in the heart. Cardiac fibroblasts (CFs) are resident cells of the heart that respond to deleterious stimuli, increasing the synthesis and secretion of both fibrotic and proinflammatory molecules. The molecular mechanisms that regulate inflammation in CFs are unknown, thus, it is important to find new targets that allow improving treatments for HG-induced cardiac dysfunction. NFκB is the master regulator of inflammation, while FoxO1 is a new participant in the inflammatory response, including inflammation induced by HG; however, its role in the inflammatory response of CFs is unknown. The inflammation resolution is essential for an effective tissue repair and recovery of the organ function. Lipoxin A4 (LXA4) is an anti-inflammatory agent with cytoprotective effects, while its cardioprotective effects have not been fully studied. Thus, in this study, we analyze the role of p65/NFκB, and FoxO1 in CFs inflammation induced by HG, evaluating the anti-inflammatory properties of LXA4. Our results demonstrated that HG induces the inflammatory response in CFs, using an in vitro and ex vivo model, while FoxO1 inhibition and silencing prevented HG effects. Additionally, LXA4 inhibited the activation of FoxO1 and p65/NFκB, and inflammation of CFs induced by HG. Therefore, our results suggest that FoxO1 and LXA4 could be novel drug targets for the treatment of HG-induced inflammatory and fibrotic disorders in the heart.

Assuntos

RESUMO

Polycystin-1 (PC1) is a transmembrane protein found in different cell types, including cardiomyocytes. Alterations in PC1 expression have been linked to mitochondrial damage in renal tubule cells and in patients with autosomal dominant polycystic kidney disease. However, to date, the regulatory role of PC1 in cardiomyocyte mitochondria is not well understood. The analysis of mitochondrial morphology from cardiomyocytes of heterozygous PC1 mice (PDK1+/- ) using transmission electron microscopy showed that cardiomyocyte mitochondria were smaller with increased mitochondria density and circularity. These parameters were consistent with mitochondrial fission. We knocked-down PC1 in cultured rat cardiomyocytes and human-induced pluripotent stem cells (iPSC)-derived cardiomyocytes to evaluate mitochondrial function and morphology. The results showed that downregulation of PC1 expression results in reduced protein levels of sub-units of the OXPHOS complexes and less functional mitochondria (reduction of mitochondrial membrane potential, mitochondrial respiration, and ATP production). This mitochondrial dysfunction activates the elimination of defective mitochondria by mitophagy, assessed by an increase of autophagosome adapter protein LC3B and the recruitment of the Parkin protein to the mitochondria. siRNA-mediated PC1 knockdown leads to a loss of the connectivity of the mitochondrial network and a greater number of mitochondria per cell, but of smaller sizes, which characterizes mitochondrial fission. PC1 silencing also deregulates the AKT-FoxO1 signaling pathway, which is involved in the regulation of mitochondrial metabolism, mitochondrial morphology, and processes that are part of cell quality control, such as mitophagy. Together, these data provide new insights about the controls that PC1 exerts on mitochondrial morphology and function in cultured cardiomyocytes dependent on the AKT-FoxO1 signaling pathway.

Assuntos

RESUMO

The skeletal muscle mass reduces 30-60% after spinal cord injury, this is mostly due to protein degradation through ubiquitin-proteasome system. In this work, we propose that the flavanol (-)-epicatechin, due its widespread biological effects on muscle health, can prevent muscle mass decrease after spinal cord injury. Thirty-six female Long Evans rats were randomized into 5 groups: (1) Spinal cord injury 7 days, (2) Spinal cord injury + (-)-epicatechin 7 days, (3) Spinal cord injury 30 days, (4) Spinal cord injury + (-)-epicatechin 30 days and (5) Sham (Only laminectomy). Hind limb perimeter, muscle cross section area, fiber cross section area and ubiquitin-proteasome system protein expression together with total protein ubiquitination were assessed. At 30 days Spinal cord injury group lost 49.52 ± 2.023% of muscle cross section area (-)-epicatechin treated group lost only 24.28 ± 15.45% being a significant difference. Ubiquitin-proteasome markers showed significant changes. FOXO1a increased in spinal cord injury group vs Sham (-)-epicatechin reduced this increase. In spinal cord injury group MAFbx increased significantly vs Sham but decrease in (-)-epicatechin treatment group at 30 days. At 7 and 30 days MuRF1 increased in the spinal cord injury and decreased in the (-)-epicatechin group. The global protein ubiquitination increases after spinal cord injury, epicatechin treatment induce a significant decrease in protein ubiquitination. These results suggest that (-)-epicatechin reduces the muscle waste after spinal cord injury through down regulation of the ubiquitin-proteasome system.

Assuntos

RESUMO

BACKGROUND AND PURPOSE: The AT2 receptor plays a role in metabolism by opposing the actions triggered by the AT1 receptors. Activation of AT2 receptors has been shown to enhance insulin sensitivity in both normal and insulin resistance animal models. In this study, we investigated the mechanism by which AT2 receptors activation improves metabolism in diabetic mice. EXPERIMENTAL APPROACH: Female diabetic (db/db) and non-diabetic (db/+) mice were treated for 1 month with the selective AT2 agonist, compound 21 (C21, 0.3 mg·kg-1 ·day-1 , s.c.). To evaluate whether the effects of C21 depend on NO production, a subgroup of mice was treated with C21 plus a sub-pressor dose of the NOS inhibitor l-NAME (0.1 mg·ml-1 , drinking water). KEY RESULTS: C21-treated db/db mice displayed improved glucose and pyruvate tolerance compared with saline-treated db/db mice. Also, C21-treated db/db mice showed reduced liver weight and decreased hepatic lipid accumulation compared with saline-treated db/db mice. Insulin signalling analysis showed increased phosphorylation of the insulin receptor, Akt and FOXO1 in the livers of C21-treated db/db mice compared with saline-treated counterparts. These findings were associated with increased adiponectin levels in plasma and adipose tissue and reduced adipocyte size in inguinal fat. The beneficial effects of AT2 receptors activation were associated with increased eNOS phosphorylation and higher levels of NO metabolites and were abolished by l-NAME. CONCLUSION AND IMPLICATIONS: Chronic C21 infusion exerts beneficial metabolic effects in female diabetic db/db mice, alleviating type 2 diabetes complications, through a mechanism that involves NO production.

Assuntos

RESUMO

The renin-angiotensin system, one of the main regulators of vascular function, controls vasoconstriction, inflammation and vascular remodeling. Antagonistic actions of the counter-regulatory renin-angiotensin system, which include vasodilation, anti-proliferative, anti-inflammatory and anti-remodeling effects, have also been described. However, little is known about the direct effects of angiotensin-(1-9), a peptide of the counter-regulatory renin-angiotensin system, on vascular smooth muscle cells. Here, we studied the anti-vascular remodeling effects of angiotensin-(1-9), with special focus on the control of vascular smooth muscle cell phenotype. Angiotensin-(1-9) decreased blood pressure and aorta media thickness in spontaneously hypertensive rats. Reduction of media thickness was associated with decreased vascular smooth muscle cell proliferation. In the A7r5 VSMC cell line and in primary cultures of rat aorta smooth muscle cells, angiotensin-(1-9) did not modify basal proliferation. However, angiotensin-(1-9) inhibited proliferation, migration and contractile protein decrease induced by platelet derived growth factor-BB. Moreover, angiotensin-(1-9) reduced Akt and FoxO1 phosphorylation at 30 min, followed by an increase of total FoxO1 protein content. Angiotensin-(1-9) effects were blocked by the AT2R antagonist PD123319, Akt-Myr overexpression and FoxO1 siRNA. These data suggest that angiotensin-(1-9) inhibits vascular smooth muscle cell dedifferentiation by an AT2R/Akt/FoxO1-dependent mechanism.

Assuntos

RESUMO

MAPK phosphatases (MKP) downregulate the activity of mitogen-activated protein kinases (MAPK), such as ERK1/2, and modulate the processes regulated by these kinases. ERK1/2 participate in a wide range of processes including tissue-specific hormone-stimulated steroidogenesis. H295R cells are a suitable model for the study of human adrenal cortex functions, particularly steroid synthesis, and respond to angiotensin II (Ang II) triggering ERK1/2 phosphorylation in a transient fashion. MKP-3 dephosphorylates ERK1/2 and, as recently reported, forkhead box protein 1 (FOXO1). Here, we analyzed MKP-3 expression in H295R cells and its putative regulation by Ang II. Results showed the expression of MKP-3 full length (L) and a short splice variant (S), and the upregulation of both isoforms by Ang II. L and S messenger and protein levels increased 30 min after Ang II stimulation and declined over the next 3 h, a temporal frame compatible with ERK1/2 dephosphorylation. In addition, FOXO1 activation is known to include its dephosphorylation and nuclear translocation. Therefore, we analyzed the effect of Ang II on FOXO1 modulation. Ang II induced FOXO1 transient phosphorylation and translocation and also the induction of p21, a FOXO1-dependent gene, whereas MKP-3 knock-down reduced both FOXO1 translocation and p21 induction. These data suggest that, through MKP-3, Ang II counteracts its own effects on ERK1/2 activity and also triggers the activation of FOXO-1 and the induction of cell cycle inhibitor p21. Taken together, the current findings reveal the participation of MKP-3 not only in turn-off but also in turn-on signals which control important cellular processes.

RESUMO

Maternal diabetes programs cardiovascular alterations in the adult offspring but the mechanisms involved remain unclarified. Here, we addresed whether maternal diabetes programs cardiac alterations related to extracellular matrix remodeling in the adult offspring, as well as the role of forkhead box transcription factor 1 (FOXO1) in the induction of these alterations. The heart from adult offspring from control and streptozotocin-induced diabetic rats was evaluated. Increased glycemia, triglyceridemia and insulinemia and markers of cardiomyopathy were found in the offspring from diabetic rats. In the heart, an increase in active FOXO1 and mRNA levels of its target genes, Mmp-2 and Ctgf, genes related to an altered extracellular matrix remodeling, together with an increase in collagen deposition and a decrease in the connexin43 levels, were found in the offspring from diabetic rats. Altogether, these results suggest an important role of FOXO1 activation in the cardiac alterations induced by intrauterine programming in maternal diabetes.

Assuntos

RESUMO

Arylamine N-acetyltransferase (NAT; E.C. 2.3.1.5) enzymes are responsible for the biotransformation of several arylamine and hydrazine drugs by acetylation. In this process, the acetyl group transferred to the acceptor substrate produces NAT deacetylation and, in consequence, it is susceptible of degradation. Sirtuins are protein deacetylases, dependent on nicotine adenine dinucleotide, which perform post-translational modifications on cytosolic proteins. To explore possible sirtuin participation in the enzymatic activity of arylamine NATs, the expression levels of NAT1, NAT2, SIRT1 and SIRT6 in peripheral blood mononuclear cells (PBMC) from healthy subjects were examined by flow cytometry and Western blot. The in situ activity of the sirtuins on NAT enzymatic activity was analyzed by HPLC, in the presence or absence of an agonist (resveratrol) and inhibitor (nicotinamide) of sirtuins. We detected a higher percentage of positive cells for NAT2 in comparison with NAT1, and higher numbers of SIRT1+ cells compared to SIRT6 in lymphocytes. In situ NAT2 activity in the presence of NAM inhibitors was higher than in the presence of its substrate, but not in the presence of resveratrol. In contrast, the activity of NAT1 was not affected by sirtuins. These results showed that NAT2 activity might be modified by sirtuins.

RESUMO

PURPOSE: The objective of the study was to investigate the role of microRNA-9 (miR-9) targeting forkhead box O1 (FOXO1) in the proliferation, migration, and invasion of breast cancer cells. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to determine the expressions of miR-9 and FOXO1 mRNA in breast cancer tissues, normal breast tissues, breast cancer cell lines, and normal breast epithelial cells. After the up-regulation of miR-9 expression, qRT-PCR and Western blotting were used to determine the expression of FOXO1. The luciferase reporter gene assay was used to validate the target gene. The CCK-8 assay, scratch-wound healing assay, and Transwell invasion assay were used to investigate the changes in the proliferation, migration, and invasion of breast cancer cells, respectively. RESULTS: MicroRNA-9 expression was significantly up-regulated in breast cancer tissues and breast cancer cell lines when compared with normal breast tissues and normal breast epithelial cells (both P < 0.05). FOXO1 mRNA and protein expressions were substantially down-regulated in breast cancer tissues and breast cancer cell lines when compared with normal breast tissues and normal breast epithelial cells (both P < 0.05). There can be a negative correlation between miR-9 and FOXO1 mRNA in breast cancer. Luciferase reporter gene assay indicated that miR-9 can down-regulate FOXO1 expression at a post-transcriptional level through binding specifically to FOXO1 3'UTR. The results of CCK-8 assay, scratch-wound healing assay, and Transwell invasion assay revealed that the inhibition of miR-9 can suppress MCF7 cell proliferation, migration, and invasion. Additionally, the expression of miR-9 increased significantly whilst that of FOXO1 decreased substantially as the disease progressed (P < 0.05). CONCLUSIONS: Our study provides evidence that miR-9 can promote the proliferation, migration, and invasion of breast cancer cells via down-regulating FOXO1.

Assuntos

RESUMO

The Kaposi's Sarcoma-associated Herpes virus G Protein-Coupled Receptor (vGPCR) is a key molecule in the pathogenesis of Kaposi Sarcoma. We have previously demonstrated that the proteasome inhibitor Bortezomib inhibits NF-κB pathway, which is required for tumor maintenance in endothelial cells that express vGPCR (vGPCR cells). In this work, we further investigated Bortezomib anti-proliferative mechanism of action. We demonstrated that Bortezomib decreases vGPCR cell number in a dose-dependent manner and induces cell morphology changes. Bortezomib decreases ERK1/2 phosphorylation whereas induces the accumulation of MKP-3 - a specific ERK1/2 MAP kinase phosphatase - in time and concentration dependent manner (1.5-32h; 0.25-1nM). The transcription factor FOXO1 is activated by dephosphorylation and regulates p21 expression. Here, we demonstrated that Bortezomib increases FOXO1 protein and decreases its phosphorylation in a concentration dependent manner (0.25-1nM). Bortezomib (0.5nM, 24h) also increase nuclear FOXO1 protein, in line with FOXO1 dephosphorylation induced by the drug. Consistent with FOXO1 dephosphorylation/activation, p21 mRNA expression is increased by Bortezomib in a MKP-3-dependent way. Bortezomib (0.5nM, 24h) also decreases VEGF, an ERK1/2 -dependent effect. It is concluded that in vGPCR cells, Bortezomib decreases ERK1/2 and FOXO1 phosphorylation through MKP-3 accumulation, leading ERK1/2 deactivation and FOXO1 activation respectively and, consequently, to cell proliferation inhibition, p21 induction and VEGF repression. Taken together, all these events contribute to the anti-tumoral effect of Bortezomib.

Assuntos

RESUMO

The maternal deficiency of vitamin D can act on organogenesis in mice offspring, being a risk factor for chronic diseases in adulthood. This study investigates the effects of maternal deficiency of vitamin D on structural islet remodeling and insulin-signaling pathway in the offspring. We studied male C57Bl/6 offspring at 3-month old (n = 10/group) from mother fed one of the two diets: control diet (C) or vitamin D-restricted diet (VitD-). After weaning, offspring only fed the control diet ad libitum. In the offspring, we studied insulin production, islet remodeling, and islet protein expression of the insulin-signaling pathway (Western blotting, isolated islet, n = 5/group). VitD- offspring showed greater glycemia (P = 0.012), smaller beta-cell mass (P = 0.014), and hypoinsulinemia (P = 0.024) than C offspring. Comparing VitD- offspring with C offspring, we observed lower protein levels in islet of insulin (P = 0.003), insulin receptor substrate-1 (P = 0.025), phosphatidylinositol-3-kinases (P = 0.045), 3-phosphoinositide-dependent protein kinase 1 (P = 0.017), protein kinase B (P = 0.028), with reduced expression of pancreas/duodenum homeobox-1 (PDX-1) (P = 0.016), glucose transporter-2 (P = 0.003), and glucokinase (P = 0.045). The maternal vitamin D-restricted diet modifies the development of the pancreas of the offspring, leading to islet remodeling and altered insulin-signaling pathway. The decrease of PDX-1 is probably significant to the changes in the beta-cell mass and insulin secretion in adulthood.

Assuntos

RESUMO

The barrier properties of endothelial cells are critical for the maintenance of water and protein balance between the intravascular and extravascular compartments. An impairment of endothelial barrier function has been implicated in the genesis and/or progression of a variety of pathological conditions, including pulmonary edema, ischemic stroke, neurodegenerative disorders, angioedema, sepsis and cancer. The altered barrier function in these conditions is often linked to the release of soluble mediators from resident cells (e.g., mast cells, macrophages) and/or recruited blood cells. The interaction of the mediators with receptors expressed on the surface of endothelial cells diminishes barrier function either by altering the expression of adhesive proteins in the inter-endothelial junctions, by altering the organization of the cytoskeleton, or both. Reactive oxygen species (ROS), proteolytic enzymes (e.g., matrix metalloproteinase, elastase), oncostatin M, and VEGF are part of a long list of mediators that have been implicated in endothelial barrier failure. In this review, we address the role of blood borne cells, including, neutrophils, lymphocytes, monocytes, and platelets, in the regulation of endothelial barrier function in health and disease. Attention is also devoted to new targets for therapeutic intervention in disease states with morbidity and mortality related to endothelial barrier dysfunction.

RESUMO

AIM: To investigate whether lycopene can modulate adiponectin levels and SIRT1 and FoxO1 gene expression in the adipose tissue of diet-induced obese rats. METHODS: Male Wistar rats were first fed with hypercaloric diet (HD, n = 12) for 6 weeks, and afterward, these rats were randomly assigned to receive HD (n = 6) or HD with lycopene-rich tomato oleoresin (equivalent to lycopene 10 mg/kg body weight (BW)/day, HD + L, n = 6) by gavage for additional 6 weeks. Plasma lycopene and adiponectin levels were analyzed by high-performance liquid chromatography and immunoassay, respectively. The messenger RNA (mRNA) expressions of adiponectin, Sirtuin 1 (SIRT1), Forkhead box O 1 (FoxO1), fatty acid translocase/cluster of differentiation 36 (FAT/CD36), and PPARγ in adipose tissues were determined by quantitative polymerase chain reaction. RESULTS: Lycopene was detected in the plasma of rats in HD + L group but not in the HD group. Although both BW and adiposity were not different between the two groups, there was a significant increase in both plasma concentration and mRNA expression of adiponectin in the adipose tissue of the HD + L group. In addition, the lycopene supplementation upregulated mRNA expressions of SIRT1, FoxO1, and FAT/CD36 but downregulated PPARγ in adipose tissue of obese rats. CONCLUSION: These data suggest that lycopene, in the concentration used, is not toxic and also its health benefits in adipose tissue may play a role against obesity-related complications.

Assuntos

RESUMO

BACKGROUND: Type 2 diabetes (T2D) and heart failure (HF) are associated with high levels of skeletal muscle (SkM) oxidative stress (OS). Health benefits attributed to flavonoids have been ascribed to antioxidation. However, for flavonoids with similar antioxidant potential, end-biological effects vary widely suggesting other mechanistic venues for reducing OS. Decreases in OS may follow the modulation of key regulatory pathways including antioxidant levels (e.g. glutathione) and enzymes such as mitochondrial superoxide dismutase (SOD2) and catalase. METHODS: We examined OS-related alterations in SkM in T2D/HF patients (as compared vs. healthy controls) and evaluated the effects of three-month treatment with (-)-epicatechin (Epi) rich cocoa (ERC). To evidence Epi as the mediator of the improved OS profile we examined the effects of pure Epi (vs. water) on SkM OS regulatory systems in a mouse model of insulin resistance and contrasted results vs. normal mice. RESULTS: There were severe alterations in OS regulatory systems in T2D/HF SkM as compared with healthy controls. Treatment with ERC induced recovery in glutathione levels and decreases in the nitrotyrosilation and carbonylation of proteins. With treatment, key transcriptional factors translocate into the nucleus leading to increases in SOD2 and catalase protein expression and activity levels. In insulin resistant mice, there were alterations in muscle OS and pure Epi replicated the beneficial effects of ERC found in humans. CONCLUSIONS: Major perturbations in SkM OS can be reversed with ERC in T2D/HF patients. Epi likely mediates such effects and may provide an effective means to treat conditions associated with tissue OS.

Assuntos