Chronic consumption of imbalance diets high in sucrose or fat induces abdominal obesity with different pattern of metabolic disturbances and lost in Langerhans cells population.

AIM: Obesity is a worldwide health issue, associated with development of type 2 Diabetes Mellitus. The aim of this study is to analyze the effect of consumption of two hypercaloric diets on metabolic disturbance and beta cells damage. MAIN METHODS: Male Wistar rats were subjected to twelve months consumption of three diets: a Control balanced diet (CTD, carbohydrates 58 %, proteins 29 %, lipids 13 %) and two hypercaloric diets, high in sucrose (HSD, carbohydrates 68 %, proteins 22 %, lipids 10 %) or high in fat (HFD, carbohydrates 31 %, proteins 14 %, lipids 55 %). Serum levels of glucose, triglycerides and free fatty acids were measured after zoometric parameters determination. Antioxidant enzymes activity and oxidative stress-marker were measured in pancreas tissue among histological analysis of Langerhans islets. KEY FINDINGS: Although diets were hypercaloric, the amount of food consumed by rats decreased, resulting in an equal caloric consumption. The HSD induced hypertriglyceridemia and hyperglycemia with higher levels in free fatty acids (FFA, lipotoxicity); whereas HFD did not increased neither the triglycerides nor FFA, nevertheless the loss of islets' cell was larger. Both diets induced obesity with hyperglycemia and significant reduction in Langerhans islets size. SIGNIFICANCE: Our results demonstrate that consumption of HSD induces more significant metabolic disturbances that HFD, although both generated pancreas damage; as well hypercaloric diet consumption is not indispensable to becoming obese; the chronic consumption of unbalanced diets (rich in carbohydrates or lipids) may lead to abdominal obesity with metabolic and functional disturbances, although the total amount of calories are similar.

Gene expression of cardiovascular risk markers in mononuclear cells of pregnant woman in relation to plasma leptin and homocysteine levels: A cross sectional study.

OBJECTIVE: To investigate the relationship between anthropometric, biochemical, and hematologic parameters and serum leptin and homocysteine (Hcy) levels. Also, to determine the effect of leptin and Hcy on expression of genes associated with cardiovascular disease susceptibility (APOA1, LRP1, COX-1, and COX-2) in mononuclear cells of healthy pregnant women. METHODS: Between August 2018 and January 2020, a cross-sectional study was conducted on 161 healthy pregnant women in Tabasco, southeastern Mexico. The study population was classified by trimester, according to gestational pregnancy. Anthropometric, biochemical (leptin and homocysteine), and hematologic data were obtained under fasting conditions. APOA1, LRP1, COX-1, and COX-2 expression in mononuclear cells was evaluated using RT-qPCR. RESULTS: Red cell indices (hemoglobin, hematocrit, and erythrocytes) were negatively and positively correlated with leptin and Hcy levels, respectively, in the first- and second-trimester groups. Increased leptin levels and low red cell indices were significantly associated with BMI <25.0 in the second-trimester group; however, no significant differences were observed in Hcy levels. Increased leptin and Hcy levels were significantly associated with high lipid indicators in the first- and third-trimester groups, respectively. High APOA1 and COX-2 expression was significantly associated with reduced leptin and increased Hcy levels in the second- and third-trimester groups. CONCLUSION: Increased leptin and Hcy levels during pregnancy, mainly associated with modifications in erythrocytes and lipid indices, may lead to early modification of genes related to lipid metabolism (APOA1) and proinflammatory response (COX-2) and, thereby, increase cardiovascular disease risk.

Differential disruption on glucose and insulin metabolism in two rat models of diet-induced obesity, based on carbohydrates or lipids.

Obesity is a relevant health public issue and is the main factor for glucose metabolism dysregulation and diabetes progression; however, the differential role of a high-fat diet or high sugar diet consumption on glucose metabolism and insulin processing is not well understood and has been scarcely described. Our research aimed to analyze the effects of chronic consumption of both high sucrose and high-fat diets on glucose and insulin metabolism regulation. Wistar rats were fed with high-sugar or high-fat diets for 12 months; after that, fasting glucose and insulin levels were measured along with a glucose tolerance test (GTT). Proteins related to insulin synthesis and secretion were quantified in pancreas homogenates, whereas islets were isolated to analyze ROS generation and size measurement. Our results show that both diets induce metabolic syndrome, linked with central obesity, hyperglycemia, and insulin resistance. We observed alterations in the expression of proteins related with insulin synthesis and secretion, along with diminution of Langerhans islets size. Interestingly, the severity and number of alterations were more evident in the high-sugar diet than in the high-fat diet group. In conclusion, obesity and glucose metabolism dysregulation induced by carbohydrate consumption, led to worst outcomes than high-fat diet.

High sugar but not high fat diet consumption induces hepatic metabolic disruption and up-regulation of mitochondrial fission-associated protein Drp1 in a model of moderate obesity.

Identification of new modifications and the association with diet patterns are essential for the prevention of non-alcoholic fatty liver disease (NAFLD). To address this problem, we feed rats with high caloric diets based on high sucrose (HSD) and high fat (HFD) and analysed metabolic and mitochondrial alterations. Both diets induce moderated obesity and fat accumulation in the liver after 8, 10 and 12 months of diet. The HSD induces both hyperleptinemia and hyperinsulinemia, as well as up-regulation of transcription factors SRBEP1 and PPARγ along slight increase nitrosylation of proteins and increased mitochondrial fission. In contrast, HFD induced hyperleptinemia without changes in neither insulin levels nor oxidative stress, SREBP1, PPARγ, or mitochondrial dynamics. In conclusion, chronic consumption of high sucrose content diets induces more pathological and metabolic alteration in liver in comparison with consumption of high-fat content diets, although both induces obesity and liver steatosis in these animal models.

Chronic exposure to ozone induces cardiac antioxidant response and overexpression of either mitochondrial fision protein DRP1 and hipertrophyc-related proteins.

Pollution is considered a risk factor for cardiovascular disease; however, the mechanisms to explain this relationship are not well understood; ozone is one of the most abundant and studied air contaminants. Our study aimed to evaluate the effect of chronic exposition of rats to controlled low doses of ozone on oxidative stress, apoptosis, mitochondrial dynamics, and cardiac hypertrophy. Male Wistar rats were daily exposed to low ozone doses during 7, 15, 30, and 60 days, 4 h/day. Hearts were dissected, and homogenates were prepared. Oxidative stress was evaluated by TBARS and protein nitrosylation in addition to Superoxide dismutase 1 (SOD1) and Catalase levels; the apoptosis related-proteins caspase 3, caspase 9, Bax, Bcl-2, and the mitochondrial dynamic-associated proteins Fis1, Drp1, OPA1, and Mfn1 were quantified by western blot among the cardiac hypertrophy indicator alpha-actin (cardiac actin). There were no changes in the oxidative stress markers, however SOD1 expression increases. Caspase 3 expression decreased, whereas caspase 9 increased without changes in Bax or Bcl-2. Mitochondrial fission may be favored according to the increased expression of Drp1 but not changes in fusion-related proteins OPA1 and Mfn1. Finally, the molecular marker for cardiac hypertrophy was overexpressed after 30 and 60 days of ozone exposition. The chronic exposition to ozone induces a deleterious effect on cardiac mitochondria. Antioxidant defenses also show changes in relation to exposure time, as well as an apparent pro-hypertrophic effect associated with altered mitochondrial dynamics.

Tauroursodeoxycholic acid (TUDCA) is neuroprotective in a chronic mouse model of Parkinson's disease.

OBJECTIVE: Parkinson's disease (PD) is a progressive motor disease of unknown etiology. Although neuroprotective ability of endogenous bile acid, tauroursodeoxycholic acid (TUDCA), shown in various diseases, including an acute model of PD,the potential therapeutic role of TUDCA in progressive models of PD that exhibit all aspects of PD has not been elucidated. In the present study, mice were assigned to one of four treatment groups: (1) Probenecid (PROB); (2) TUDCA, (3) MPTP + PROB (MPTPp); and (3) TUDCA + MPTPp. Methods: Markers for dopaminergic function, neuroinflammation, oxidative stress and autophagy were assessed using high performance liquid chromatography (HPLC), immunohistochemistry (IHC) and western blot (WB) methods. Locomotion was measured before and after treatments. Results: MPTPp decreased the expression of dopamine transporters (DAT) and tyrosine hydroxylase (TH), indicating dopaminergic damage, and induced microglial and astroglial activation as demonstrated by IHC analysis. MPTPp also decreased DA and its metabolites as demonstrated by HPLC analysis. Further, MPTPp-induced protein oxidation; increased LAMP-1 expression indicated autophagy and the promotion of alpha-synuclein (α-SYN) aggregation. Discussion: Pretreatment with TUDCA protected against dopaminergic neuronal damage, prevented the microglial and astroglial activation, as well as the DA and DOPAC reductions caused by MPTPp. TUDCA by itself did not produce any significant change, with data similar to the negative control group. Pretreatment with TUDCA prevented protein oxidation and autophagy, in addition to inhibiting α-SYN aggregation. Although TUDCA pretreatment did not significantly affect locomotion, only acute treatment effects were measured, indicating more extensive assessments may be necessary to reveal potential therapeutic effects on behavior. Together, these results suggest that autophagy may be involved in the progression of PD and that TUDCA may attenuate these effects. The efficacy of TUDCA as a novel therapy in patients with PD clearly warrants further study.

Anthropometric, biochemical, and haematological indicators associated with hyperhomocysteinemia and their relation to global DNA methylation in a young adult population.

Increased homocysteine (Hcy) levels have been associated with a higher risk of cardiovascular and neurodegenerative diseases. Passive DNA demethylation has been suggested as one of the mechanisms implicated in the development of these conditions, and most studies have investigated this relationship in older adult populations. Therefore, this study aimed to evaluate the relationship between corporal composition and biochemical and haematological indicators with plasma homocysteine levels and genome-wide methylation (Alu, LINE-1, and SAT2) in a population of healthy young adults (median age, 18 years). We showed that the prevalence of hyperhomocysteinemia was significantly higher in men (18.5%) than in women (6.6%) (P = 0.034). Increased Hcy level was substantially associated with higher levels of body mass index and visceral fat in females, whereas in males, it was significantly associated with reduced red cell distribution width and high-density lipoprotein (HDL) cholesterol (HDL-C) levels and increased low-density lipoprotein/HDL ratio. Hypomethylation of Alu was significantly associated with reduced levels of HDL-C (<40.0 mg dL-1), whereas hypomethylation of LINE-1 and SAT2 was significantly associated with higher levels of skeletal muscle (<39.3%) in males. These results highlight the participation of hormonal factors in regulating Hcy metabolism, primarily in the female population, whereas changes in DNA methylation observed in males might be associated with the consumption of a protein diet with high levels of methionine, independent of increased Hcy levels.

Oxidative Stress Caused by Ozone Exposure Induces Changes in P2X7 Receptors, Neuroinflammation, and Neurodegeneration in the Rat Hippocampus.

Low-ozone doses cause alterations in the oxidation-reduction mechanisms due to the increase in reactive oxygen species, alter cell signaling, and produce deleterious metabolic responses for cells. Adenosine 5'triphosphate (ATP) can act as a mediator in intercellular communication between neurons and glial cells. When there is an increase in extracellular ATP, a modification is promoted in the regulation of inflammation, energy metabolism, by affecting the intracellular signaling pathways that participate in these processes. The objective of this work was to study changes in the P2X7 receptor, and their relationship with the inflammatory response and energy metabolism, in a model of progressive neurodegeneration in the hippocampus of rats chronically exposed to low-ozone doses. Therefore, 72 male rats were exposed to low-ozone doses for different periods of time. After exposure to ozone was finished, rats were processed for immunohistochemical techniques, western blot, quantitative polymerase chain reaction (qPCR), and histological techniques for periodic acid-Schiff staining. The results showed immunoreactivity changes in the amount of the P2X7 protein. There was an increase in phosphorylation for glycogen synthase kinase 3-ß (GSK3-ß) as treatment continued. There were also increases in 27 interleukin 1 beta (IL-1 ß) and interleukin 17 (IL-17) and a decrease in interleukin 10 (IL-10). Furthermore, neuronal glycogen was found at 30 and 60 days, and an increase in caspase 3. An increase in mRNA was also shown for the P2X7 gene at 60 days, and GSK3-ß at 90 days of exposure. In conclusion, these results suggest that repeated exposure to low-ozone doses, such as those that can occur during highly polluted days, causes a state of oxidative stress, leading to alterations in the P2X7 receptors, which promote changes in the activation of signaling pathways for inflammatory processes and cell death, converging at a progressive neurodegeneration process, as may be happening in Alzheimer's disease.

The high-risk HPV E6 proteins modify the activity of the eIF4E protein via the MEK/ERK and AKT/PKB pathways.

Previous studies have proposed that the human papillomavirus (HPV) E6 oncoproteins modify the transcriptional activity of eIF4E through mechanisms dependent on p53 degradation. However, the effect of these oncoproteins on pathways regulating the activity of the eIF4E protein remains poorly understood. Hence, we investigated the mechanisms whereby E6 proteins regulate the activity of the eIF4E protein and its effect on target genes. Overexpression of E6 constructs (HPV-6, HPV-16, HPV-18, and HPV52) showed that E6 oncoproteins increased phosphorylation of the eIF4E protein (Serine-209). This result was mainly mediated by phosphorylation of the 4EBP1 protein via the PI3K/AKT pathway. Additionally, the pharmacological inhibition of eIF4E phosphorylation in cervical cancer cell lines substantially reduced the protein levels of CCND1 and ODC1, indicating that E6 of the high-risk genotypes may modify protein synthesis of the eIF4E target genes by increasing the activity of the AKT and ERK pathways.

Internalization of Titanium Dioxide Nanoparticles Is Mediated by Actin-Dependent Reorganization and Clathrin- and Dynamin-Mediated Endocytosis in H9c2 Rat Cardiomyoblasts.

Titanium dioxide nanoparticles (TiO2 NPs) are widely used for industrial and commercial applications. Once inside the body, they translocate into the bloodstream and reach different areas of the cardiovascular system including the heart, increasing the risk of developing cardiovascular diseases; consequently, the investigation of their interaction with cardiac cells is required. We previously showed that TiO2 NPs are internalized by H9c2 rat cardiomyoblasts, and here, we examined the molecular mechanisms underlying this process. TiO2 NPs internalization was evaluated by transmission electron microscopy, time-lapse microscopy, and flow cytometry. Changes in the actin cytoskeleton were studied by phalloidin staining. Endocytic uptake mechanisms for nanoparticles were probed with chemical inhibitors, whereas clathrin and dynamin expression was measured by Western blot. Cellular uptake of TiO2 NPs occurred early after 30 min exposure, and large aggregates were observed after 1 h. Actin cytoskeleton reorganization included cell elongation plus lower density and stability of actin fibers. Cytochalasin-D inhibited TiO2 NPs uptake, indicating actin-mediated internalization. Dynamin and clathrin levels increased early after TiO2 NPs exposure, and their inhibition reduced nanoparticle uptake. Therefore, TiO2 NPs internalization by H9c2 rat cardiomyoblasts involves actin cytoskeleton reorganization and clathrin/dynamin-mediated endocytosis.

Leptin Modifies the Rat Heart Performance Associated with Mitochondrial Dysfunction Independently of Its Prohypertrophic Effects.

BACKGROUND: Functional receptors for leptin were described on the surface of cardiomyocytes, and there was a prohypertrophic effect with high concentrations of the cytokine. Therefore, leptin could be a link between obesity and the prevalence of cardiovascular diseases. On the other hand, a deleterious effect of leptin on mitochondrial performance was described, which was also associated with the evolution of cardiac hypertrophy to heart failure. The goal of our study was to analyze the effect of the exposure of rat hearts to a high concentration of leptin on cardiac and mitochondrial function. METHODS: Rat hearts were perfused continuously with or without 3.1 nM leptin for 1, 2, 3, or 4 hours. Homogenates and mitochondria were prepared by centrifugation and analyzed for cardiac actin, STAT3, and pSTAT3 by Western blotting, as well as for mitochondrial oxidative phosphorylation, membrane potential, swelling, calcium transport, and content of oxidized lipids. RESULTS: In our results, leptin induced an increased rate-pressure product as a result of increased heart rate and contraction force, as well oxidative stress. In addition, mitochondrial dysfunction expressed as a loss of membrane potential, decreased ability for calcium transport and retention, faster swelling, and less respiratory control was observed. CONCLUSIONS: Our results support the role of leptin as a deleterious factor for cardiac function and indicates that mitochondrial dysfunction could be a trigger for cardiac hypertrophy and failure.

Characterization of Biaxial Stretch as an In Vitro Model of Traumatic Brain Injury to the Blood-Brain Barrier.

Traumatic brain injury (TBI) is one of the major causes of disability in the USA. It occurs when external mechanical forces induce brain damage that causes deformation of brain tissue. TBI is also associated with alterations of the blood-brain barrier (BBB). Using primary rat brain microvascular endothelial cells as an in vitro BBB model, the effects of biaxial stretch were characterized at 5, 10, 15, 25, and 50% deformation using a commercially available system. The results were compared to the effects of mild and moderate TBI in vivo, induced by the weight-drop method in mice. In vitro, live/dead cells, lactate dehydrogenase (LDH) release, caspase 3/7 staining, and tight junction (TJ) protein expression were evaluated 24 h after a single stretch episode. In vivo, Evans blue extravasation, serum levels of S100ß, and TJ protein expression were evaluated. Stretch induced a deformation-dependent increase in LDH release, cell death, and activation of caspase 3/7, suggesting the induction of apoptosis. Interestingly, low magnitudes of deformation increased the expression of TJ proteins, likely in an attempt to compensate for stretch damage. High magnitudes of deformation decreased the expression of TJ proteins, suggesting that the damage was too severe to counteract. In vivo, mild TBI did not affect BBB permeability or the expression of TJ proteins. However, moderate TBI significantly increased BBB permeability and decreased the expression of these proteins, similar to the results obtained with a high magnitude deformation. These data support the use biaxial stretch as valuable tool in the study of TBI in vitro.

Oxidative stress activates the transcription factors FoxO 1a and FoxO 3a in the hippocampus of rats exposed to low doses of ozone.

The exposure to low doses of ozone induces an oxidative stress state, which is involved in neurodegenerative diseases. Forkhead box O (FoxO) family of transcription factors are activated by oxidative signals and regulate cell proliferation and resistance to oxidative stress. Our aim was to study the effect of chronic exposure to ozone on the activation of FoxO 1a and FoxO 3a in the hippocampus of rats. Male Wistar rats were divided into six groups and exposed to 0.25 ppm of ozone for 0, 7, 15, 30, 60, and 90 days. After treatment, the groups were processed for western blotting and immunohistochemistry against FoxO 3a, Mn SOD, cyclin D2, FoxO 1a, and active caspase 3. We found that exposure to ozone increased the activation of FoxO 3a at 30 and 60 days and expression of Mn SOD at all treatment times. Additionally, increases in cyclin D2 from 7 to 90 days; FoxO 1a at 15, 30, and 60 days; and activate caspase 3 from 30 to 60 days of exposure were noted. The results indicate that ozone alters regulatory pathways related to both the antioxidant system and the cell cycle, inducing neuronal reentry into the cell cycle and apoptotic death.

Bax induces cytochrome c release by multiple mechanisms in mitochondria from MCF7 cells.

Bax, a pro-apoptotic member of the Bcl-2 family of proteins has the ability to form transmembrane pores large enough to allow cytochrome c (Cyt c) release, as well as to activate the mitochondrial permeability transition pore (mPTP); however, no differential study has been conducted to clarify which one of these mechanisms predominates over the other in the same system. In the present study, we treated isolated mitochondria from MCF7 cells with recombinant protein Bax and tested the efficacy of the mPTP inhibitor cyclosporin A (CsA) and of the Bax channel blocker (Bcb) to inhibit cytochrome c release. We also, induced apoptosis in MCF7 cell cultures with TNF-α plus cycloheximide to determine the effect of such compounds in apoptosis induction via mPTP or Bax oligomerization. Cytochrome c release was totally prevented by CsA and partially by Bcb when apoptosis was induced with recombinant Bax in isolated mitochondria from MCF7 cells. CsA increased the number of living cells in cell culture, as compared with the effect of Bax channel blocker. These results indicate that mPTP activation is the predominant pathway for Bax-induced cytochrome c release from MCF7 mitochondria and for apoptosis induction in the whole cell.