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Simple Summary: In February 2022, the university course Replacing Animal Testing (RAT) Challenge was organized for the first time by an alliance of Dutch universities with the aim of engaging future generations in finding solutions to replace the use of animals in testing. Educating the next generations of researchers and professionals is an important step in the transition to promote animal-free science, to which the Dutch government is committed. Students are key stakeholders in the transition to animal-free innovations but their perspective still remains underrepresented. Therefore, our study aimed to explore their viewpoints focusing on their beliefs, values, and the motivations of students to join the course. We conclude that students share the ethical and scientific values that inspire the transition, and that their reflections on the socio-political landscape provide valuable insights on current and future challenges to the acceptance of animal-free innovations. In 2016, the Dutch government declared its commitment to phasing out animal experiments by 2025. Although a high number of animal experiments are still performed and the 2025 target will not be met, the commitment remains. Efforts are being made to identify levers that might foster the transition to animal-free science. Education has been found to play a key role in the future of animal-free science and young generations are increasingly seen as key stakeholders. However, their attitudes toward the transition to animal-free innovations have not been investigated. The present article focuses on the values and beliefs held by students, who in 2022, participated in the course 'Replacing Animal Testing' (RAT) Challenge, organized by a consortium of Dutch universities. Contextually, students' motivations to follow the course were investigated. The research was based on a qualitative study, including semi-structured interviews and a literature review. Our analysis of the findings revealed that students feel aligned with the social, ethical, and scientific reasons that support the transition to animal-free innovations. Moreover, the participants identified a series of regulatory, educational, cultural, and political obstacles to the transition that align with those identified in recent literature. From the discussion of these findings, we extrapolated six fundamental challenges that need to be addressed to foster the transition to animal-free science in an acceptable and responsible way. [ABSTRACT FROM AUTHOR]

Steinbusch LK, Luiken JJ, Viasbiom R, Chabowski A, Hoebers NT, Coumans WA, Vroegrijk IO, Voshol PJ, Ouwens DM, Glatz JF, Diamant M. Absence of fatty acid transporter CD36 protects against Western-type diet-related cardiac dysfunction following pressure over- load in mice. Am J Physiol Endocrinol Metab 301: E61 8-E627, 2011. First published June 28, 2011; doi:10.1152/ajpendo.00106.2011.--Car- diac patients often are obese and have hypertension, but in most studies these conditions are investigated separately. Here, we aimed at l) elucidating the interaction of metabolic and mechanophysical stress in the development of cardiac dysfunction in mice and 2) preventing this interaction by ablation of the fatty acid transporter CD36. Male wild-type (WT) C57B1/6 mice and CD36-/- mice received chow or Western-type diet (WTD) for 10 wk and then underwent a sham surgery or transverse aortic constriction (TAC) under anesthesia. After a 6-wk continuation of the diet, cardiac function, morphology, lipid profiles, and molecular parameters were assessed. WTD admin- istration affected body and organ weights of WT and CD36~ mice, but it affected only plasma glucose and insulin concentrations in WT mice. Cardiac lipid concentrations increased in WT mice receiving WTD, decreased in CD36~ on chow, and remained unchanged in CD36~ receiving WTD. TAC induced cardiac hypertrophy in WT mice on chow but did not affect cardiac function and cardiac lipid concentrations. WTD or CD36 ablation worsened the outcome of TAC. Ablation of CD36 protected against the WTD-related aggrava- tion of cardiac functional and structural changes induced by TAC. In conclusion, cardiac dysfunction and remodeling worsen when the heart is exposed to two stresses, metabolic and mechanophysical, at the same time. CD36 ablation prevents the metabolic stress resulting from a WTD. Thus, metabolic conditions are a critical factor for the compromised heart and provide new targets for metabolic manipula- tion in cardioprotection. [ABSTRACT FROM AUTHOR]

In neonatal ventricular cardiomyocytes (NVCM), decreased contractile activity stimulates sarco-endoplasmic reticulum Ca2+-ATPase2a (SERCA2a), analogous to reduced myocardial load in vivo. This study investigated in contracting NVCM the role of load-dependent RhoA-ROCK signaling in SERCA2a regulation. Contractile arrest of NVCM resulted in low peri-nuclear localized RhoA levels relative to contracting NVCM. In arrested NVCM, ROCK activity was decreased (59%) and paralleled a loss in F-actin levels. Y-27632-induced ROCK inhibition in contracting NVCM increased SERCA2a messenger RNA expression by 150%. This stimulation was transcriptional, as evident from transfections with the SERCA2a promoter. A reciprocal effect of Y-27632 treatment on the promoter activity of atrial natriuretic factor was observed. SERCA2a transcription was not altered by co-transfection of the RhoA-ROCK-dependent serum response factor (SRF) alone or in combination with myocardin. Furthermore, GATA4, another ROCK-dependent transcription factor, induced rather than repressed SERCA2a transcription. This study shows that contractile activity suppresses SERCA2a gene expression via RhoA-ROCK-dependent transcription modulation. This modulation is likely to be accomplished by a transcription factor other than SRF, myocardin, or GATA4. [ABSTRACT FROM AUTHOR]

Clinical insulin resistance is associated with decreased activation of phosphatidylinositol 3'-kinase (PI3K) and its downstream substrate protein kinase B (PKB)/Akt. However, its physiological protein substrates remain poorly characterized. In the present study, the effect of in vivo insulin action on phosphorylation of the PKB/Akt substrate 40 (PRAS40) was examined. In rat and mice, insulin stimulated PRAS40-Thr246 phosphorylation in skeletal and cardiac muscle, the liver, and adipose tissue in vivo. Physiological hyperinsulinemia increased PRAS40-Thr246 phosphorylation in human skeletal muscle biopsies. In cultured cell lines, insulin-mediated PRAS40 phosphorylation was prevented by the PI3K inhibitors wortmannin and LY294002. Immunohistochemical and immunofluorescence studies showed that phosphorylated PRAS40 is predominantly localized to the nucleus. Finally, in rats fed a high-fat diet (HFD), phosphorylation of PRAS40 was markedly reduced compared with low-fat diet-fed animals in all tissues examined. In conclusion, the current study identifies PRAS40 as a physiological target of in vivo insulin action. Phosphorylation of PRAS40 is increased by insulin in human, rat, and mouse insulin target tissues. In rats, this response is reduced under conditions of HFD-induced insulin resistance. Diabetes 55:3221-3228, 2006 [ABSTRACT FROM AUTHOR]

Objective: Downregulation of sarco-endoplasmic reticulum calcium ATPase 2a (SERCA2a) expression is a critical marker of pathological myocardial hypertrophy. The effects of calcium-dependent signaling and of contractile activity on the regulation of myocardial SERCA2a expression remain unclear. The present study dissociates effects of calcium-dependent signaling through calcineurin (CN) and calmodulin dependent protein kinase-II (CAMK-II), from effects of contractile activity in spontaneously contracting rat neonatal ventricular cardiomyocytes (NVCM) using 2,3-butanedione monoxime (BDM), which arrests contractions but maintains calcium fluxes. Methods: SERCA2a mRNA expression was analysed using Northern hybridisation in spontaneously contracting NVCM (control) and in NVCM treated with either BDM, L-type Ca2+-channel blocker (verapamil), CN-blocker (cyclosporin A; CsA), CAMK-II blocker (KN-93), or combinations thereof. Transient transfection of the CN-dependent transcription factor nuclear factor of activated T-lymphocytes (NFATc), coupled to GFP, was used to detect NFAT nuclear translocation. The effects of CN/CAMK-II-dependent signaling were further dissected into effects of the transcription factors NFATc4 and myocyte enhancer factor 2c (MEF2c) on the activity of various SERCA2a promoter fragments using transient transfection assays. Results: Treatment with BDM induced a 2.5-fold rise in SERCA2a mRNA, which was abolished by addition of verapamil and was reduced by addition of CsA (-40%) and KN-93 (-20%). NFAT nuclear translocation was similar in control and BDM-treated NVCM. SERCA2a promoter activity was stimulated by NFATc4 and MEF2c, but only when both factors were co-transfected. Conclusion: Following contractile arrest with BDM, upregulation of SERCA2a mRNA expression by CN/CAMK-II signaling becomes evident. This upregulation is likely the result of synergistic stimulation of SERCA2a promoter activity by NFATc4 and MEF2c. Contractile activity opposes this upregulation through distinct and independent pathways. [Copyright &y& Elsevier]

Abstract Background. Availability of the essential nutrient iron is thought to vary greatly in the gastric mucosa, and thus the human gastric pathogen Helicobacter pylori requires regulatory responses to these environmental changes. Bacterial iron-responsive regulation is often mediated by Ferric Uptake Regulator (Fur) homologs, and in this study we have determined the role of H. pylori Fur in regulation of H. pylori iron uptake. Methods. Wild-type H. pylori and fur mutant derivatives were compared after growth in iron-restricted and iron-replete conditions. Iron-uptake was measured using 55 Fe-labeled iron, whereas gene expression was monitored at the transcriptional level using Northern hybridization and lacZ reporter gene fusions. Results. Iron-uptake and total cellular iron content were approximately five-fold increased in the fur mutant compared with the wild-type strain, which indicated that in the fur mutant iron-uptake is not repressed by excess iron. A comprehensive screening of all H. pylori genes encoding putative iron-uptake proteins indicated that some of these H. pylori genes are constitutively expressed, while others are iron- and Fur-regulated. Conclusions. Iron uptake in H. pylori is in part differently regulated compared with other bacteria, since in H. pylori some iron-uptake systems are constitutively expressed. However, other iron uptake systems of H. pylori display the iron- and Fur-mediated repression that is common in bacteria. Taken together, this Fur-mediated modulation of iron-uptake capacity may be a specific adaptation to the conditions in the human stomach, where iron starvation and iron overload can be encountered in relatively short time intervals. [ABSTRACT FROM AUTHOR]

Type 2 diabetes (DM2) and the metabolic syndrome (MetS) are conditions associated with a high risk of coronary artery disease (CAD) and congestive heart failure (CHF). Although CAD contributes to diastolic dysfunction and left ventricular (LV) stiffness, the interaction between CAD, DM2 and the MetS, is largely unknown. We studied the impact of CAD, DM2 and the MetS on LV function and stiffness in patients who underwent a diagnostic coronary angiography. Sixty patients (n=22 with and n=21 without the MetS and n=17 with DM2; n=38 males were studied. Only subjects with LV ejection fraction >40% were included to avoid the confounding of post myocardial infarction remodeling. CAD severity was determined according to the number of the vessels with >50% stenosis. Thus, 26 patients had no CAD, 14 had 1, 9 had 2, 11 had 3 vessel disease. Hemodynamic and echocardiographic data were collected and combined to calculate percent LV wall thickening (LVWT%), a measure of systolic function, as well as LV end-diastolic wall thickness (LVWTed) and myocardial stiffness modulus, both variables of diastolic function. LVWT% did not differ among groups. DM2 subjects and those with the MetS had higher LVWTed than controls (P=0.019), but LV stiffness was not increased. Patients with vs those without CAD had higher LVWTed (P=0.022) and lower LVWT% (P=0.031). A trend for increased LV stiffness in CAD patients was observed (P=0.158). LV stiffness worsened according to the number of vessels involved (P=0.044). Multivariate analyses revealed CAD as an independent determinant of LV stiffness, after correction for age, gender and fasting glucose, in patients with MetS and DM2 (P=0.002), but not in controls (P=0.895). In conclusion, increased LVWTed was observed in subjects with the MetS and DM2, vs controls, and in patients with relative to those without CAD. We show that the contribution of CAD to LV stiffness depends on the presence of dysmetabolic conditions including the MetS and DM2. These findings implicate that strategies aiming early detection and treatment of CAD in people with MetS and DM2 may prevent future development of CHF. [ABSTRACT FROM AUTHOR]

Presents the table of contents for the August 2002 issue of the periodical 'Helicobacter.' 'The Role of Ferric Uptake Regulator (Fur) in Regulation of Helicobacter pylori Iron Uptake,' by Arnoud H.M. van Vliet and colleagues; 'A Novel Method for Assessing Gastritis in the Murine Model Demonstrates Genetically Determined Variation in Response to Helicobacter felis Infection,' by M.M. Walker, M. Worku, S. Coggle and M.R. Thursz.