1. Investigación

Scope: fructose consumption from added sugars correlates with the epidemic rise in MetS and CVD. Maternal fructose intake has been described to program metabolic diseases in progeny. However, consumption of fructose-containing beverages is allowed during gestation. Cholesterol is also a well-known risk factor for CVD. Therefore, it is essential to study Western diets which combine fructose and cholesterol and how maternal fructose can influence the response of progeny to these diets. Methods and results: a high-cholesterol (2%) diet combined with liquid fructose (10%), as a model of an unhealthy Western diet, was administered to descendants from control and fructose-fed mothers. Gene (mRNA and protein) expression and plasma, fecal and tissue parameters of cholesterol metabolism were measured. Interestingly, progeny from fructose-fed dams consumed less liquid fructose and cholesterol-rich chow than males from control mothers. Moreover, descendants of fructose-fed mothers fed a Western diet showed an increased cholesterol elimination through bile and feces than males from control mothers. Despite these mitigating circumstances to develop a proatherogenic profile, the same degree of hypercholesterolemia and severity of steatosis were observed in all descendants fed a Western diet, independently of maternal intake. An increased intestinal absorption of cholesterol, synthesis, esterification, and assembly into lipoprotein found in males from fructose-fed dams consuming a Western diet could be the cause. Moreover, an augmented GLP2 signalling seen in these animals would explain this enhanced lipid absorption. Conclusions: maternal fructose intake, through a fetal programming, makes a Western diet considerably more harmful in their descendants than in the offspring from control mothers.

Metabolic Syndrome (MetS) is a risk factor for the development of neurodegenerative diseases. Neuroinflammation associated with MetS may contribute significantly to neurodegeneration. Pleiotrophin (PTN) is a neurotrophic factor that modulates neuroinflammation and is a key player in regulating energy metabolism and thermogenesis, suggesting that PTN could be important in the connection between MetS and neuroinflammation. We have now used a high-fat diet (HFD)-induced obesity model in Ptn-/- mice. HFD and Ptn deletion caused alterations in circulating hormones including GIP, leptin and resistin. HFD produced in Ptn+/+ mice a neuroinflammatory state as observed in cerebral quantifications of proinflammatory markers, including Il1β, Tnfα and Ccl2. The upregulation of neuroinflammatory markers was prevented in Ptn-/- mice. Changes induced by HFD in genes related to mitochondrial biogenesis and dynamics were less pronounced in the brain of Ptn-/- mice and were accompanied by significant increases in the protein expression of mitochondrial oxidative phosphorylation (OXPHOS) complexes I and IV. HFD-induced changes in genes related to the elimination of protein aggregates were also less pronounced in the brain of Ptn-/- mice. This study provides substantial evidence that Ptn deletion protects against HFD-induced neuroinflammation, mitochondrial dysfunction, and aberrant protein aggregation, prominent features in neurodegenerative diseases.

Pleiotrophin (PTN) is a cytokine that is upregulated in different neuroinflammatory disorders. Using mice with transgenic PTN overexpression in the brain (Ptn-Tg), we have found a positive correlation between iNos and Tnfα mRNA and Ptn mRNA levels in the prefrontal cortex (PFC) of LPS-treated mice. PTN is an inhibitor of Receptor Protein Tyrosine Phosphatase (RPTP) β/ζ, which is mainly expressed in the central nervous system. We aimed to test if RPTPβ/ζ is involved in the modulation of neuroinflammatory responses using specific inhibitors of RPTPβ/ζ (MY10 and MY33-3). Treatment with MY10 potentiated LPS-induced microglial responses in the mouse PFC. Surprisingly, MY10 caused a decrease in LPS-induced NF-κB p65 expression, suggesting that RPTPβ/ζ may be involved in a novel mechanism of potentiation of microglial activation independent of the NF-κB p65 pathway. MY33-3 and MY10 limited LPS-induced nitrites production and iNos increases in BV2 microglial cells. SH-SY5Y neuronal cells were treated with the conditioned media from MY10/LPS-treated BV2 cells. Conditioned media from non-stimulated and from LPS-stimulated BV2 cells increased the viability of SH-SY5Y cultures. RPTPβ/ζ inhibition in microglial cells disrupted this neurotrophic effect of microglia, suggesting that RPTPβ/ζ plays a role in the neurotrophic phenotype of microglia and in microglia-neuron communication.

Adolescence is a critical period for brain maturation in which this organ is more vulnerable to the damaging effects of ethanol. Administration of ethanol in mice induces a rapid cerebral upregulation of pleiotrophin (PTN), a cytokine that regulates the neuroinflammatory processes induced by different insults and the behavioral effects of ethanol. PTN binds Receptor Protein Tyrosine Phosphatase (RPTP) β/ζ and inhibits its phosphatase activity, suggesting that RPTPβ/ζ may be involved in the regulation of ethanol effects. To test this hypothesis, we have treated adolescent mice with the RPTPβ/ζ inhibitor MY10 (60 mg/kg) before an acute ethanol (6 g/kg) administration. Treatment with MY10 completely prevented the ethanol-induced neurogenic loss in the hippocampus of both male and female mice. In flow cytometry studies, ethanol tended to increase the number of NeuN+/activated Caspase-3+ cells particularly in female mice, but no significant effects were found. Ethanol increased Iba1+ cell area and the total marked area in the hippocampus of female mice, suggesting sex differences in ethanol-induced microgliosis. In addition, ethanol reduced the circulating levels of IL-6 and IL-10 in both sexes, although this reduction was only found significant in males and not affected by MY10 treatment. Interestingly, MY10 alone increased the total marked area and the number of Iba1+ cells only in the female hippocampus, but tended to reduce the circulating levels of TNF-α only in male mice. In summary, the data identify a novel modulatory role of RPTPβ/ζ on ethanol-induced loss of hippocampal neurogenesis, which seems unrelated to glial and inflammatory responses. The data also suggest sex differences in RPTPβ/ζ function that may be relevant to immune responses and ethanol-induced microglial responses.

Gestational Diabetes Mellitus (GDM) is characterized by abnormal maternal D-glucose metabolism and altered insulin signaling. Dysregulation of thyroid hormones (TH) triiodethyronine (T3) and L-thyroxine (T4) Hormones had been associated with GDM, but the physiopathological meaning of these alterations is still unclear. Maternal TH cross the placenta through TH Transporters and their Deiodinases metabolize them to regulate fetal TH levels. Currently, the metabolism of TH in placentas with GDM is unknown, and there are no other studies that evaluate the fetal TH from pregnancies with GDM. Therefore, we evaluated the levels of maternal TH during pregnancy, and fetal TH at delivery, and the expression and activity of placental deiodinases from GDM pregnancies. Pregnant women were followed through pregnancy until delivery. We collected blood samples during 10–14, 24–28, and 36–40 weeks of gestation for measure Thyroid-stimulating hormone (TSH), Free T4 (FT4), Total T4 (TT4), and Total T3 (TT3) concentrations from Normal Glucose Tolerance (NGT) and GDM mothers. Moreover, we measure fetal TSH, FT4, TT4, and TT3 in total blood cord at the delivery. Also, we measured the placental expression of Deiodinases by RT-PCR, western-blotting, and immunohistochemistry. The activity of Deiodinases was estimated quantified rT3 and T3 using T4 as a substrate. Mothers with GDM showed higher levels of TT3 during all pregnancy, and an increased in TSH during second and third trimester, while lower concentrations of neonatal TT4, FT4, and TT3; and an increased TSH level in umbilical cord blood from GDM. Placentae from GDM mothers have a higher expression and activity of Deiodinase 3, but lower Deiodinase 2, than NGT mothers. In conclusion, GDM favors high levels of TT3 during all gestation in the mother, low levels in TT4, FT4 and TT3 at the delivery in neonates, and increases deiodinase 3, but reduce deiodinase 2 expression and activity in the placenta.

Pleiotrophin is a pleiotropic cytokine that has been demonstrated to have a critical role in regulating energy metabolism, lipid turnover and plasticity of adipose tissue. Here, we hypothesize that this cytokine can be involved in regulatory processes of glucose and lipid homeostasis in the liver during pregnancy. Using 18-days pregnant Ptn-deficient mice, we evaluated the biochemical profile (circulating variables), tissue mRNA expression (qPCR) and protein levels of key enzymes and transcription factors involved in main metabolic pathways. Ptn deletion was associated with a reduction in body weight gain, hyperglycemia and glucose intolerance. Moreover, we observed an impairment in glucose synthesis and degradation during late pregnancy in Ptn−/− mice. Hepatic lipid content was significantly lower (73.6%) in Ptn−/− mice and was associated with a clear reduction in fatty acid, triacylglycerides and cholesterol synthesis. Ptn deletion was accompanying with a diabetogenic state in the mother and a decreased expression of key proteins involved in glucose and lipid uptake and metabolism. Moreover, Ptn−/− pregnant mice have a decreased expression of transcription factors,such as PPAR-α, regulating lipid uptake and glucose and lipid utilization. Furthermore, the augmented expression and nuclear translocation of glycerol kinase, and the decrease in NUR77 protein levels in the knock-out animals can further explain the alterations observed in hepatic glucose metabolism. Our results point out for the first time that pleiotrophin is an important player in maintaining hepatic metabolic homeostasis during late gestation, and further highlighted the moonlighting role of glycerol kinase in the regulation of maternal glucose homeostasis during pregnancy.

Osteoarthritis is a degenerative disease, often resulting in chronic joint pain and commonly affecting elderly people. Current treatments with anti-inflammatory drugs are palliative, making the discovery of new treatments necessary. The inhibition of matrix metalloproteinase MMP-13 is a validated strategy to prevent the progression of this common joint disorder. We recently described polybrominated benzotriazole derivatives with nanomolar inhibitory activity and a promising selectivity profile against this collagenase. In this work, we have extended the study in order to explore the influence of bromine atoms and the nature of the S10 heterocyclic interacting moiety on the solubility/selectivity balance of this type of compound. Drug target interactions have been assessed through a combination of molecular modeling studies and NMR experiments. Compound 9a has been identified as a water-soluble and highly potent inhibitor with activity in MG-63 human osteosarcoma cells.