Akt Is Controlled by Bag5 through a Monoubiquitination to Polyubiquitination Switch.

The serine-threonine kinase Akt plays a fundamental role in cell survival, metabolism, proliferation, and migration. To keep these essential processes under control, Akt activity and stability must be tightly regulated; otherwise, life-threatening conditions might prevail. Although it is well understood that phosphorylation regulates Akt activity, much remains to be known about how its stability is maintained. Here, we characterize BAG5, a chaperone regulator, as a novel Akt-interactor and substrate that attenuates Akt stability together with Hsp70. BAG5 switches monoubiquitination to polyubiquitination of Akt and increases its degradation caused by Hsp90 inhibition and Hsp70 overexpression. Akt interacts with BAG5 at the linker region that joins the first and second BAG domains and phosphorylates the first BAG domain. The Akt-BAG5 complex is formed in serum-starved conditions and dissociates in response to HGF, coincident with BAG5 phosphorylation. BAG5 knockdown attenuated Akt degradation and facilitated its activation, whereas the opposite effect was caused by BAG5 overexpression. Altogether, our results indicate that Akt stability and signaling are dynamically regulated by BAG5, depending on growth factor availability.

Risky sexual behaviors in adolescents and young adult women with type 1 diabetes: An overlooked problem.

The presence of unprotected sex activity in women living with type 1 diabetes (T1D) who have insufficient glycemic control should be considered as a specific risky behavior. To evaluate risky behaviors, including unprotected sexual activity, sources of information and knowledge related to reproductive health in adolescents and young adult women with T1D (PwT1D) compared to a group of adolescents and young adult women without diabetes (Comparison group). PwT1D and the Comparison group completed a questionnaire with validated measures that assessed reproductive health. PwT1D (n = 115, age = 17.7 ± 3.2 years) and Comparison group (n = 386, age = 18.3 ± 2.9) were recruited. The proportion of women reporting having sex without any contraceptive was similar in both groups (57.1% and 50%, in PwT1D and Comparison group, respectively). The use of non-effective contraceptive was reported in 63.2% and 63.6% of the PwT1D and Comparison group, respectively. Among PwT1D, parents, formal sex education, and friends were the primary source of information on reproductive health. Low levels of knowledge about diabetes and pregnancy were observed in PwT1D. HbA1c level was associated with having at least one sexual activity without any contraception (OR = 1.63, p = 0.039). PwT1D have similar rates of risky behaviors compared to a Comparison group. Sexual risky behaviors should be especially considered in PwT1D with glycemic control above the optimal level. Parents are an important source of reproductive health information for PwT1D. Use of effective contraception should be reinforced in sexually active PwT1D.

Comparación del contenido de azúcares y edulcorantes no calóricos en néctares y bebidas antes y después de implementar la ley chilena 20606 / Comparison of sugar and non- caloric sweetener content in beverages before and after implementing Chilean law 20606

RESUMEN Para enfrentar el problema de sobrepeso y obesidad en Chile, el enfoque de las políticas públicas debe enfatizar en medidas preventivas, cambiando el entorno en que el individuo se desarrolla para ayudarle a tener un estilo de vida más saludable. La Ley 20.606, tiene por objetivo principal proteger la salud de los chilenos, en especial de los niños, incorporando un marco regulatorio que contempla etiquetado frontal de advertencia en alimentos, prohibición de publicidad dirigida a menores de 14 años y prohibición de venta de alimentos con altos niveles de nutrientes críticos en establecimientos escolares. Las bebidas y néctares azucarados representan una de las fuentes más importantes de azúcares añadidos en la dieta y son de alto consumo por la población chilena. Por tal motivo se revisó la información nutricional y lista de ingredientes en etiquetas de néctares y bebidas de fantasía comercializadas en Chile, antes y después de la promulgación de la Ley 20.606. Los resultados mostraron que las formulaciones de los productos comercializados en el año 2017 se modificaron disminuyendo la concentración de azúcar, sin embargo, se incorporaron edulcorantes no calóricos, los que se encuentran cuestionados por muchos investigadores por posibles efectos adversos para la salud.

ABSTRACT To address the problem of overweight and obesity in Chile, the focus of public policies should emphasize preventive measures to change the environment in which the individual develops and help facilitate a healthier lifestyle. The main objective of the Chilean law 20.606 is to protect the health of Chileans, especially children, by incorporating a regulatory framework that includes a frontal warning labeling on food, a ban on advertising aimed at children under 14 and a ban on the sale of foods with high levels of critical nutrients in schools. Sugar sweetened beverages represent the largest source of added dietary sugars and discretionary calories for Chileans. For this reason, nutritional information and the ingredient list for the nutritional labeling of soft drinks commercialized in Chile were reviewed, before and after enactment of Chilean law 20.606. The results indicated that the formulations of products marketed in 2017 were modified by decreasing the concentration of sugar, however non-caloric sweeteners were incorporated, which are questioned by many researchers for possible adverse effects on health.

AT1R antagonism improves metabolic and vascular changes of obesity-induced gestational diabetes mellitus.

Obesity can overload glucose homeostasis and physiological insulin resistance during gestation which increases the risk of complications like diabetes mellitus or preeclampsia. Angiotensin II /AT1 receptors are involved in the pathogenesis of vascular effects of obesity/insulin resistance but its role during gestation is not as clear. We sought to determine angiotensin II- AT1R participation on a diet-induced gestational diabetes mellitus (GDM) experimental model. Female Wistar rats were fed with a standard or hypercaloric diet for 7 weeks. Half of the animals were mated and became pregnant from week 4-7. Animals were treated with saline, irbesartan (30 mg/kg) or metformin (320 mg/kg) for the last two weeks of the protocol. Weight gain, systolic blood pressure (BP), oral glucose tolerance test and vascular contractility were measured at the last day of the protocol (day 19-20 of pregnancy). Hypercaloric diet increased blood glucose, impaired glucose tolerance test, and increased BP in pregnant rats, fulfilling criteria for GDM. Both drugs decreased impaired GTT and relative hyperglycemia. Metformin had no effect on BP but prevented weight increase. In isolated aortas, irbesartan and metformin decreased vasoconstriction only of non-pregnant hypercaloric diet fed animals. Results support angiotensin II/ AT1R involvement in BP and glucose homeostasis disturbances observed in present GDM model. Also, provide evidence that a hypercaloric diet can mask pregnancy´s physiological hypoglycemia and hypotension without surpassing non-pregnant values. Then, we conclude overweight during pregnancy causes subtle but significant vascular and metabolic damage that might be dismissed in clinical practice.

Algas marinas como ingrediente funcional en productos cárnicos / Seaweed as a functional ingredient in meat products

RESUMEN Las algas marinas constituyen un valioso recurso para el desarrollo de productos alimenticios gracias a su composición nutricional, contienen alta concentración de proteínas, vitaminas, minerales y fibra dietética, que en el caso de las algas es particularmente rica en fracción soluble. Las algas además contienen componentes beneficiosos para la salud, como ácidos grasos ω-3 y moléculas bioactivas, con actividad antioxidante, antiinflamatoria, anticancerígena y antidiabética. Además, poseen propiedades tecnológicas, por lo que su incorporación en alimentos procesados y especialmente productos cárnicos como salchichas, hamburguesas, emulsiones cárnicas y otras, resulta beneficioso desde el punto de vista tecnológico y sensorial, siempre que se incorpore en una concentración adecuada.

ABSTRACT Seaweed is a valuable resource for food development due to its nutritional composition. It is high in protein, vitamins, minerals and dietary fiber, and particularly rich in soluble fiber. Seaweed also contains components beneficial to health such as ω-3 PUFAs, bioactive molecules with antioxidants, and anti-inflammatory, anticancer, and antidiabetic activity. It also has technological properties, so its incorporation in processed foods and especially meat products such as sausages, hamburgers, meat emulsions and others would be beneficial from the technological and sensorial point of view, if it is incorporated in an adequate concentration.

Time course of angiotensin II dependent vascular and metabolic effects of preeclampsia.

Pregnancy is characterized by a blunted pressor response to angiotensin II that is progressively lost during preeclampsia complicated pregnancies. Renin angiotensin system (RAS) plays a pivotal role in cardiovascular and renal function but its role in normal and pathological pregnancy is far from being clarified. It is not as clear if hypertension and particularly pregnancy-induced hypertension as the initial event, can trigger some of the metabolic syndrome components, and if these changes are angiotensin II mediated. The aim of this study was to determine the time course of angiotensin II contribution to the vascular and eventual metabolic changes of preeclampsia. An experimental model was developed by reducing feto-placental circulation through a subrenal aorta coarctation before pregnancy in rats. Control and pregnant (preeclamptic) animals were treated with captopril (5mg/kgpo) or saline solution for 21, 14 or 7days before delivery, and their body weight, plasma glucose andblood pressure were registered. Phenylephrine (Phe) induced contraction was evaluated using isolated aorta rings. Preeclampsia increased blood pressure (2nd and 3rd wk) but also weight (3rd wk) and glucose values (2nd and 3rd week). Captopril (for 21 or 14days) treatment prevented increases in blood pressure and plasma glucose but not in body weight. Also, captopril treatment significantly increased aorta contractility. These results provide evidence that cardiovascular and metabolic disturbances of preeclampsia appear simultaneously and are angiotensin II dependent.

Evidence of changes in alpha-1/AT1 receptor function generated by diet-induced obesity.

To study whether hypercaloric diet-induced obesity deteriorates vascular contractility of rat aorta through functional changes in α1 adrenergic and/or AT1 Angiotensin II receptors. Angiotensin II- or phenylephrine-induced contraction was tested on isolated aorta rings with and without endothelium from female Wistar rats fed for 7 weeks with hypercaloric diet or standard diet. Vascular expression of Angiotensin II Receptor type 1 (AT1R), Angiotensin II Receptor type 2 (AT2R), Cyclooxygenase-1 (COX-1), Cyclooxygenase-2 (COX-2), inducible Nitric Oxide Synthase (iNOS) and endothelial Nitric Oxide Synthase (eNOS), as well as blood pressure, glucose, insulin and angiotensin II blood levels were measured. Diet-induced obesity did not significantly change agonist-induced contractions (Emax and pD2 hypercaloric diet vs standard diet n.s.d.) of both intact (e+) or endothelium free (e-) vessels but significantly decrease both phenylephrine and angiotensin II contraction (Emax p < 0.01 hypercaloric diet vs standard diet) in the presence of both prazosin and losartan but only in endothelium-intact vessels. Diet-induced obesity did not change angiotensin II AT1, AT2 receptor proteins expression but reduced COX-1 and NOS2 ( p < 0.05 vs standard diet). Seven-week hypercaloric diet-induced obesity produces alterations in vascular adrenergic and angiotensin II receptor dynamics that suggest an endothelium-dependent adrenergic/angiotensin II crosstalk. These changes reflect early-stage vascular responses to obesity.

Gßγ Pathways in Cell Polarity and Migration Linked to Oncogenic GPCR Signaling: Potential Relevance in Tumor Microenvironment.

Cancer cells and stroma cells in tumors secrete chemotactic agonists that exacerbate invasive behavior, promote tumor-induced angiogenesis, and recruit protumoral bone marrow-derived cells. In response to shallow gradients of chemotactic stimuli recognized by G protein-coupled receptors (GPCRs), Gßγ-dependent signaling cascades contribute to specifying the spatiotemporal assembly of cytoskeletal structures that can dynamically alter cell morphology. This sophisticated process is intrinsically linked to the activation of Rho GTPases and their cytoskeletal-remodeling effectors. Thus, Rho guanine nucleotide exchange factors, the activators of these molecular switches, and their upstream signaling partners are considered participants of tumor progression. Specifically, phosphoinositide-3 kinases (class I PI3Ks, ß and γ) and P-Rex1, a Rac-specific guanine nucleotide exchange factor, are fundamental Gßγ effectors in the pathways controlling directionally persistent motility. In addition, GPCR-dependent chemotactic responses often involve endosomal trafficking of signaling proteins; coincidently, endosomes serve as signaling platforms for Gßγ In preclinical murine models of cancer, inhibition of Gßγ attenuates tumor growth, whereas in cancer patients, aberrant overexpression of chemotactic Gßγ effectors and recently identified mutations in Gß correlate with poor clinical outcome. Here we discuss emerging paradigms of Gßγ signaling in cancer, which are essential for chemotactic cell migration and represent novel opportunities to develop pathway-specific pharmacologic treatments.

Experimental gestational diabetes mellitus induces blunted vasoconstriction and functional changes in the rat aorta.

Diabetic conditions increase vascular reactivity to angiotensin II in several studies but there are scarce reports on cardiovascular effects of hypercaloric diet (HD) induced gestational diabetes mellitus (GDM), so the objective of this work was to determine the effects of HD induced GDM on vascular responses. Angiotensin II as well as phenylephrine induced vascular contraction was tested in isolated aorta rings with and without endothelium from rats fed for 7 weeks (4 before and 3 weeks during pregnancy) with standard (SD) or hypercaloric (HD) diet. Also, protein expression of AT1R, AT2R, COX-1, COX-2, NOS-1, and NOS-3 and plasma glucose, insulin, and angiotensin II levels were measured. GDM impaired vasoconstrictor response (P < 0.05 versus SD) in intact (e+) but not in endothelium-free (e-) vessels. Losartan reduced GDM but not SD e- vasoconstriction (P < 0.01 versus SD). AT1R, AT2R, and COX-1 and COX-2 protein expression were significantly increased in GDM vessels (P < 0.05 versus SD). Results suggest an increased participation of endothelium vasodilator mediators, probably prostaglandins, as well as of AT2 vasodilator receptors as a compensatory mechanism for vasoconstrictor changes generated by experimental GDM. Considering the short term of rat pregnancy findings can reflect early stage GDM adaptations.

mTORC1- and mTORC2-interacting proteins keep their multifunctional partners focused.

The mammalian target of rapamycin, best known as mTOR, is a phylogenetically conserved serine/threonine kinase that controls life-defining cellular processes such as growth, metabolism, survival, and migration under the influence of multiple interacting proteins. Historically, the cellular activities blocked by rapamycin in mammalian cells were considered the only events controlled by mTOR. However, this paradigm changed with the discovery of two signaling complexes differentially sensitive to rapamycin, whose catalytic component is mTOR. The one sensitive to rapamycin, known as mTORC1, promotes protein synthesis in response to growth factors and nutrients via the phosphorylation of p70S6K and 4EBP1; while the other, known as mTORC2, promotes cell migration and survival via the activation of Rho GTPases and the phosphorylation of AKT, respectively. Although mTORC2 kinase activity is not inhibited by rapamycin, hours of incubation with this antibiotic can impede the assembly of this signaling complex. The direct mechanism by which mTORC2 leads to cell migration depends on its interaction with P-Rex1, a Rac-specific guanine nucleotide exchange factor, while additional indirect pathways involve the intervention of PKC or AKT, multifunctional ubiquitous serine/threonine kinases that activate effectors of cell migration upon being phosphorylated by mTORC2 in response to chemotactic signals. These mTORC2 effectors are altered in metastatic cancer. Numerous clinical trials are testing mTOR inhibitors as potential antineoplasic drugs. Here, we briefly review the actions of mTOR with emphasis on the controlling role of mTORC1 and mTORC2-interacting proteins and highlight the mechanisms linked to cell migration.

Regulation of mTORC1 complex assembly and signaling by GRp58/ERp57.

The mammalian target of rapamycin (mTOR) regulates cell growth and survival via two different multiprotein complexes, mTORC1 and mTORC2. The assembly of these serine-threonine kinase multiprotein complexes occurs via poorly understood molecular mechanisms. Here, we demonstrate that GRp58/ERp57 regulates the existence and activity of mTORC1. Endogenous mTOR interacts with GRp58/ERp57 in different mammalian cells. In vitro, recombinant GRp58/ERp57 preferentially interacts with mTORC1. GRp58/ERp57 knockdown reduces mTORC1 levels and phosphorylation of 4E-BP1 and p70(S6K) in response to insulin. In contrast, GRp58/ERp57 overexpression increases mTORC1 levels and activity. A redox-sensitive mechanism that depends on GRp58/ERp57 expression activates mTORC1. Although GRp58/ERp57 is known as an endoplasmic reticulum (ER) resident, we demonstrate its presence at the cytosol, together with mTOR, Raptor, and Rictor as well as a pool of these proteins associated to the ER. In addition, the presence of GRp58/ERp57 at the ER decreases in response to insulin or leucine. Interestingly, a fraction of p70(S6K), but not 4E-BP1, is associated to the ER and phosphorylated in response to serum, insulin, or leucine. Altogether, our results suggest that GRp58/ERp57 is involved in the assembly of mTORC1 and positively regulates mTORC1 signaling at the cytosol and the cytosolic side of the ER.

Angiotensin-II-dependent changes in alpha-1 adrenoceptor vascular expression in pregnant rats.

Vessels from pregnant animals show a blunted response to adrenergic agonists. In this work, we explored if pregnancy reduces alpha(1)-adrenergic receptor (alpha(1)-AR)-mediated vascular smooth muscle protein expression as well as agonist-induced contraction in rat aorta, and if angiotensin II (Ang II) levels during pregnancy are related to these changes. Female Wistar rats were divided randomly into nonpregnant (NP) and pregnant groups (first week: P1, second week: P2, third week: P3). Subsets of animals were treated with captopril (5 mg kg(-1) day(-1) for 7 days; n = 6). Phenylephrine (PHE) concentration-response curves were constructed (1 x 10(-9) to 3.1 x 10(-5) mol/l) and alpha(1A)-, alpha(1B)- and alpha(1D)-AR were measured in the aorta by immunoblot. Captopril decreased alpha-AR expression in the NP group. In contrast, pregnancy decreased alpha(1A)-, alpha(1B)- and alpha(1D)-AR levels and captopril prevented this reduction. PHE sensitivity was decreased in the thoracic and abdominal aorta in the P2 group, with no changes in E(max ), and E(max) was decreased in the abdominal aorta in all experimental groups. Our results suggest that Ang II levels during pregnancy are related to a decrease in aortic alpha(1)-AR expression. The physiological meaning of this finding remains to be established.

Increased alpha-1 adrenoceptor expression in pregnant rats with subrenal aortic coarctation.

UNLABELLED: The progression of pregnancy is associated with attenuation in vasopressor response to adrenergic agonists. In pregnancy-induced hypertension this attenuation is reverted. It is not known if this reversion involves alpha-1 adrenoceptor expression. OBJECTIVE: In this work we propose that in pregnant rats with subrenal aortic coarctation there are changes in the expression of alpha-1 adrenergic receptors in the thoracic and abdominal aorta during pregnancy. METHODS: We used non-pregnant, normal pregnant and pregnant with subrenal aortic coarctation female Wistar rats. Pregnancy-induced hypertension indicators, systolic blood pressure, 24 hours proteinuria, pup weight and maternal weight were measured. Dose response curves to phenylephrine were carried out to determine vascular reactivity along pregnancy. Alpha 1-adrenoceptors were detected from thoracic and abdominal aorta using immunoblot. RESULTS: Results show significant increases in arterial pressure and proteinuria in pregnant rats with SRAC at the end of the third week. Pregnancy reduces alpha-(1-A, -B) and (-D) adrenoceptor expression and this event is reverted by subrenal aortic coarctation. This phenomenon is more apparent in the abdominal segment of the aorta. CONCLUSIONS: These findings suggest that subrenal aortic coarctation is a good animal model of pregnancy-induced hypertension and that alpha1-adrenoceptors participate in its physiopathology increasing their expression in a segment-dependent manner.

Effect of pregnancy on the roles of nitric oxide and prostaglandins in 5-hydroxytryptamine-induced contractions in rat isolated thoracic and abdominal aorta.

1. Vascular resistance and sensitivity to circulating pressor and vasoconstrictor substances are blunted during pregnancy. This has been attributed mainly to an increased production of endothelium-derived mediators. The aim of the present study was to determine whether pregnancy changes the relative participation of nitric oxide (NO) and prostaglandins (PG) in the modulation of the contractile response to 5-hydroxytryptamine (5-HT) in two anatomically distint segments of the rat aorta. 2. Full concentration-response curves to 5-HT were obtained in isolated rings from the thoracic and abdominal portion of the aorta from pregnant and non-pregnant rats in the presence and absence of the NO synthase (NOS) inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME; 10 micromol/L) or the PG synthesis inhibitor indomethacin (10 micromol/L). Cyclo-oxygenase (COX)-1, COX-2 and endothelial (e) NOS protein expression were determined in the same tissues by immunoblot. 3. The effects of pregnancy were accentuated in the abdominal compared with the thoracic aorta. In addition, the relative participation of the NO and PG pathways seems to be changed during pregnancy. Although NO seems to be the mediator mainly responsible for the effect of pregnancy in the thoracic aorta, our results suggest a complex interaction between NO and PG in the abdominal aorta. Indomethacin significantly reduced the contractile response of both segments of the aorta, whereas expression of COX-1, COX-2 and eNOS were increased only in the abdominal segment of pregnant animals. 4. These results show that the effect of pregnancy is not homogeneous along the aorta. There seems to be a mutual interaction between PG and NO in the abdominal, but not in the thoracic, aorta from pregnant rats: the role of NO becomes evident in the absence of vasodilatory PG, whereas the participation of the latter increases in the absence of NO working as a compensatory mechanism.