Chemical shift imaging at 4.7 tesla of brown adipose tissue.

In vivo distinction between small deposits of brown adipose tissue (BAT) and surrounding tissues may be difficult. In this article, we propose an experiment paradigm, based on techniques of chemical shift magnetic resonance imaging (CSI), which can improve the methods presently available for the study of BAT. Male rats were examined in an imager-spectrometer equipped with a 4.7 T magnet. Proton spectra of isolated BAT deposits showed that both fat and water protons contributed significantly to the genesis of the magnetic resonance signal. An equivocal definition of BAT deposits was obtained by three (respectively, spin-echo, water-selective, and fat-selective) images. The spin-echo (SE), T1-weighted image provided the best anatomical description of the structures. The images selective for fat-protons displayed the degree of lipid accumulation in each area. The images selective for water-protons provided an internal control of adipose tissue localization. The proposed paradigm allows an unequivocal definition of BAT deposits and appears particularly useful in studies where experimental manipulation (i.e., cold acclimation or drug treatment) produces changes in this issue

The role of HMG-CoA reductase inhibition in endothelial dysfunction and inflammation

Statin-induced inhibition of HMG-CoA reductase reduces cholesterol production and prevents the formation of many non-steroidal isoprenoid compounds, such as farnesylpyrophosphate and geranylgeranylpyrophosphate, that act as lipid attachments for the post-translational modification of various proteins, including the G-proteins and transcription factors involved in a number of cell processes. However, the blockade of isoprenylation elicited by statin treatment also has biological effects on cell function that go beyond the decrease in cholesterol synthesis: these are the so-called “pleiotropic” effects that mainly relate to vascular function. Endothelial dysfunction is an independent predictor of cardiovascular events that correlates with inflammation markers/mediators and robust predictors of cardiovascular diseases such as increased high-sensitivity C-reactive protein levels. The results of in vivo and in vitro studies indicate that the statins have beneficial effects unrelated to cholesterol lowering, such as improving endothelial function, increasing myocardial perfusion, and enhancing the availability of nitric oxide. This review describes the pleiotropic effects of statins that may be involved in modulating/preventing endothelial dysfunction and inflammatory processes, as well as the cellular and molecular mechanisms through which they improve endothelial function

Terutroban, a Thromboxane/Prostaglandin Endoperoxide Receptor Antagonist, Increases Survival in Stroke-Prone Rats by Preventing Systemic Inflammation and Endothelial Dysfunction: Comparison with Aspirin and Rosuvastatin

ABSTRACT This study investigated the efficacy of terutroban, a specific thromboxane/prostaglandin endoperoxide receptor antagonist, on stroke incidence in spontaneously hypertensive strokeprone rats (SHRSP). The effects of terutroban were compared with those of aspirin, another antiplatelet agent, and rosuvastatin, known to exert end-organ protection in SHRSP. Saltloaded male SHRSP were treated orally once a day with vehicle, terutroban (30 mg/kg/day), aspirin (60 mg/kg/day), or rosuvastatin (10 mg/kg/day). Compared with vehicle, and regardless of any effect on blood pressure or serum thromboxane B 2 levels, terutroban significantly increased survival (p Ͻ 0.001) as a consequence of a delayed brain lesion occurrence monitored by magnetic resonance imaging (p Ͻ 0.001), and a delayed increase of proteinuria (p Ͻ 0.001). Terutroban decreased cerebral mRNA transcription of interleukin-1␤, transforming growth factor-␤, and monocyte chemoattractant protein-1 after 6 weeks of dietary treatment. Terutroban also prevented the accumulation of urinary acute-phase proteins at high molecular weight, identified as markers of systemic inflammation, and assessed longitudinally by one-dimensional electrophoresis. Terutroban also has protective effects on the vasculature as suggested by the preservation of endothelial function and endothelial nitric-oxide synthase expression in isolated carotid arteries. These effects are similar to those obtained with rosuvastatin, and superior to those of aspirin. Terutroban increases survival in SHRSP by reducing systemic inflammation as well as preserving endothelial function. These data support clinical development of terutroban in the prevention of cerebrovascular and cardiovascular complications of atherothrombosis. Several clinical and experimental studies Spontaneously hypertensive stroke-prone rats (SHRSP) develop hypertension and proteinuria and die after the onset Article, publication date, and citation information can be found a

The Recently Identified P2Y-Like Receptor GPR17 Is a Sensor of Brain Damage and a New Target for Brain Repair

Deciphering the mechanisms regulating the generation of new neurons and new oligodendrocytes, the myelinating cells of the central nervous system, is of paramount importance to address new strategies to replace endogenous damaged cells in the adult brain and foster repair in neurodegenerative diseases. Upon brain injury, the extracellular concentrations of nucleotides and cysteinyl-leukotrienes (cysLTs), two families of endogenous signaling molecules, are markedly increased at the site of damage, suggesting that they may act as “danger signals” to alert responses to tissue damage and start repair. Here we show that, in brain telencephalon, GPR17, a recently deorphanized receptor for both uracil nucleotides and cysLTs (e.g., UDP-glucose and LTD4), is normally present on neurons and on a subset of parenchymal quiescent oligodendrocyte precursor cells. We also show that induction of brain injury using an established focal ischemia model in the rodent induces profound spatiotemporal-dependent changes of GPR17. In the lesioned area, we observed an early and transient up-regulation of GPR17 in neurons expressing the cellular stress marker heat shock protein 70. Magnetic Resonance Imaging in living mice showed that the in vivo pharmacological or biotechnological knock down of GPR17 markedly prevents brain infarct evolution, suggesting GPR17 as a mediator of neuronal death at this early ischemic stage. At later times after ischemia, GPR17 immuno-labeling appeared on microglia/macrophages infiltrating the lesioned area to indicate that GPR17 may also acts as a player in the remodeling of brain circuitries by microglia. At this later stage, parenchymal GPR17+ oligodendrocyte progenitors started proliferating in the peri-injured area, suggesting initiation of remyelination. To confirm a specific role for GPR17 in oligodendrocyte differentiation, the in vitro exposure of cortical pre-oligodendrocytes to the GPR17 endogenous ligands UDP-glucose and LTD4 promoted the expression of myelin basic protein, confirming progression toward mature oligodendrocytes. Thus, GPR17 may act as a “sensor” that is activated upon brain injury on several embryonically distinct cell types, and may play a key role in both inducing neuronal death inside the ischemic core and in orchestrating the local remodeling/repair response. Specifically, we suggest GPR17 as a novel target for therapeutic manipulation to foster repair of demyelinating wounds, the types of lesions that also occur in patients with multiple sclerosis

Magnetic resonance imaging of human endothelial progenitors reveals opposite effects on vascular and muscle regeneration into ischaemic tissues

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Molecular Modelling of NONO and SFPQ Dimerization Process and RNA Recognition Mechanism

NONO and SFPQ are involved in multiple nuclear processes (e.g., pre-mRNA splicing, DNA repair, and transcriptional regulation). These proteins, along with NEAT1, enable paraspeckle formation, thus promoting multiple myeloma cell survival. In this paper, we investigate NONO and SFPQ dimer stability, highlighting the hetero- and homodimer structural differences, and model their interactions with RNA, simulating their binding to a polyG probe mimicking NEAT1guanine-rich regions. We demonstrated in silico that NONO::SFPQ heterodimerization is a more favorable process than homodimer formation. We also show that NONO and SFPQ RRM2 subunits are primarily required for protein–protein interactions with the other DBHS protomer. Simulation of RNA binding to NONO and SFPQ, beside validating RRM1 RNP signature importance, highlighted the role of β2 and β4 strand residues for RNA specific recognition. Moreover, we demonstrated the role of the NOPS region and other protomer’s RRM2 β2/β3 loop in strengthening the interaction with RNA. Our results, having deepened RNA and DBHS dimer interactions, could contribute to the design of small molecules to modulate the activity of these proteins. RNA-mimetics, able to selectively bind to NONO and/or SFPQ RNA-recognition site, could impair paraspeckle formation, thus representing a first step towards the discovery of drugs for multiple myeloma treatment

Murine left atrium and left atrial appendage structure and function: echocardiographic and morphologic evaluation.

Aim of this study was to provide an echocardiographic protocol for the description of the normal murine venous reservoir (atrium, appendage and pulmonary veins) and to investigate the possibility to use this approach to discriminate changes on left atrium (LA) and left atrial appendage (LAA) in a stress-induced model such us myocardial infarction. Global left ventricular function and the venous reservoir were assessed by a Vevo2100 in 20 female C57BL/6N. LA and LAA were also studied in 10 CD-1 and 10 FVB mice, whereas modifications investigated in 15 C57BL/6N subjected to coronary artery ligation. Left ventricle function was evaluated as well as pulsed Doppler mitral valve, pulmonary vein, and LAA velocities. From 2D view monoplane LA volumes were obtained and LAA long axis measured. Macroscopic inspection with casts and immunohistochemistry were performed. Results show that compared to humans, in C57BL/6N mice left atrium was disproportionately smaller (5.2±1.4 μL) than the left ventricle (53±8 μL) and connected through a duct by a large LAA and posteriorly to three pulmonary veins. The LA volume increased 2-fold during reservoir with two distinct phases, early and late divided by a short pause. LAA long axis (4.1±0.5 mm) was almost 2 times longer than the LA. LAA flow volume together with LA volume reservoir account for about 36% of stroke volume and the rest was provided by conduit flow. Linear regressions showed that stroke volume was strongly influenced by LAA flow, LA early filling volume and left ventricle base descent. Moreover, we also report the ability to assess LA and LAA in other mice strains and discriminate size increase following myocardial infarction. In conclusion, we performed a complete characterization of murine left venous reservoir establishing an optimized protocol that can be used in both investigative and pharmacological studies requiring rapid and serial determination of cardiac structure and function