Anxiolytic effect of alamandine in male transgenic rats with low brain angiotensinogen is dependent on activation of MrgD receptors.

Alamandine is a peptide hormone belonging to the renin-angiotensin system (RAS). It acts through the Mas-related G-protein coupled receptor type D, MrgD, which is expressed in different tissues, including the brain. In the present study, we hypothesize that a lack of alamandine, through MrgD, could cause the anxiety-like behavior in transgenic rats with low brain angiotensinogen [TGR(ASrAOGEN)680]. Adult male transgenic rats exhibited a significant increase in the latency to feeding time in the novelty suppressed feeding test and a decrease in the percentage of time and entries in the open arms in the elevated plus maze. These effects were reversed by intracerebroventricular infusion of alamandine. Pretreatment with D-Pro7-Ang-(1-7), a Mas and MrgD receptor antagonist, prevented the anxiolytic effects induced by this peptide. However, its effects were not altered by the selective Mas receptor antagonist, A779. In conclusion, our data indicates that alamandine, through MrgD, attenuates anxiety-like behavior in male TGR(ASrAOGEN)680, which reinforces the importance of the counter-regulatory RAS axis as promising target for the treatment of neuropsychiatric disorders.

ISCEV standard for clinical pattern electroretinography (2024 update).

The pattern electroretinogram (PERG) is a localized retinal response evoked by a contrast-reversing pattern, usually a black and white checkerboard, which provides information about macular and retinal ganglion cell function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV; www.iscev.org ) presents an updated and revised Standard for clinical PERG testing. This replaces the 2013 and all earlier versions. Minimum protocols for basic PERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis and monitoring purposes, while responding to evolving clinical practices and technology. The main changes in the updated ISCEV Standard for clinical PERG include expanded guidance about large stimulus fields, stimulus parameters for simultaneous PERG and pattern visual evoked potential recording, baseline drift correction, and use of consistent ambient room lighting. These changes aim to provide a clinically relevant document about current practice which will facilitate good quality recordings and inter-laboratory comparisons.

The Mas agonist CGEN-856S prevents Ang II induced cardiomyocyte hypertrophy via nitric oxide production.

With the previous knowledge of the cardioprotective effects of the Angiotensin-(1-7) axis, a agonist of Mas receptor has been described, the CGEN-856S. This peptide is more stable than Ang-(1-7), and has a low binding affinity to Angiotensin II receptors. Although the cardioprotective effects of CGEN-856S were previously shown in vivo, the mechanisms behind its effects are still unknown. Here, we employed a combination of molecular biology, confocal microscopy, and genetically modified mouse with Mas deletion to investigate the CGEN-856S protective signaling in cardiomyocytes. In isolated adult ventricular myocytes, CGEN-856S induced an increase in nitric oxide (NO) production which was absent in cells from Mas knockout mice. Using western blot, we observed a significant increase in phosphorylation of AKT after treatment with CGEN-856S. In addition, CGEN-856S prevented the Ang II induced hypertrophy and the nuclear translocation of GRK5 in a culture model of rat neonatal cardiomyocytes. Blockage of Mas receptor and inhibition of the NO synthase abolished the effects of CGEN-856S on Ang II treated cardiomyocytes. In conclusion, we show that CGEN-856S acting via receptor Mas induces NO raise to block Ang II induced cardiomyocyte hypertrophy. These results indicate that CGEN-856S acts very similarly to Ang-(1-7) in cardiac myocytes, highlighting its therapeutic potential for treating cardiovascular diseases.

Alternative Renin-Angiotensin System.

The renin-angiotensin system is the most important peptide hormone system in the regulation of cardiovascular homeostasis. Its classical arm consists of the enzymes, renin, and angiotensin-converting enzyme, generating angiotensin II from angiotensinogen, which activates its AT1 receptor, thereby increasing blood pressure, retaining salt and water, and inducing cardiovascular hypertrophy and fibrosis. However, angiotensin II can also activate a second receptor, the AT2 receptor. Moreover, the removal of the C-terminal phenylalanine from angiotensin II by ACE2 (angiotensin-converting enzyme 2) yields angiotensin-(1-7), and this peptide interacts with its receptor Mas. When the aminoterminal Asp of angiotensin-(1-7) is decarboxylated, alamandine is generated, which activates the Mas-related G-protein-coupled receptor D, MrgD (Mas-related G-protein-coupled receptor type D). Since Mas, MrgD, and the AT2 receptor have opposing effects to the classical AT1 receptor, they and the enzymes and peptides activating them are called the alternative or protective arm of the renin-angiotensin system. This review will cover the historical aspects and the current standing of this recent addition to the biology of the renin-angiotensin system.

ISCEV and IPS guideline for the full-field stimulus test (FST).

The full-field stimulus test (FST) is a psychophysical technique designed for the measurement of visual function in low vision. The method involves the use of a ganzfeld stimulator, as used in routine full-field electroretinography, to deliver full-field flashes of light. This guideline was developed jointly by the International Society for Clinical Electrophysiology of Vision (ISCEV) and Imaging and Perimetry Society (IPS) in order to provide technical information, promote consistency of testing and reporting, and encourage convergence of methods for FST. It is intended to aid practitioners and guide the formulation of FST protocols, with a view to future standardisation.

Autoregulation of blood flow drives early hypotension in a rat model of systemic inflammation induced by bacterial lipopolysaccharide.

Uncontrolled vasodilation is known to account for hypotension in the advanced stages of sepsis and other systemic inflammatory conditions, but the mechanisms of hypotension in earlier stages of such conditions are not clear. By monitoring hemodynamics with the highest temporal resolution in unanesthetized rats, in combination with ex-vivo assessment of vascular function, we found that early development of hypotension following injection of bacterial lipopolysaccharide is brought about by a fall in vascular resistance when arterioles are still fully responsive to vasoactive agents. This approach further uncovered that the early development of hypotension stabilized blood flow. We thus hypothesized that prioritization of the local mechanisms of blood flow regulation (tissue autoregulation) over the brain-driven mechanisms of pressure regulation (baroreflex) underscored the early development of hypotension in this model. Consistent with this hypothesis, an assessment of squared coherence and partial-directed coherence revealed that, at the onset of hypotension, the flow-pressure relationship was strengthened at frequencies (<0.2 Hz) known to be associated with autoregulation. The autoregulatory escape to phenylephrine-induced vasoconstriction, another proxy of autoregulation, was also strengthened in this phase. The competitive demand that drives prioritization of flow over pressure regulation could be edema-associated hypovolemia, as this became detectable at the onset of hypotension. Accordingly, blood transfusion aimed at preventing hypovolemia brought the autoregulation proxies back to normal and prevented the fall in vascular resistance. This novel hypothesis opens a new avenue of investigation into the mechanisms that can drive hypotension in systemic inflammation.

Brown adipose tissue transcriptome unveils an important role of the Beta-alanine/alamandine receptor, MrgD, in metabolism.

Alamandine is a recently described heptapeptide component of the renin-angiotensin system (RAS), and its effects are mediated by the receptor Mas-related G protein-coupled receptor D (MrgD) RAS represents an important link between obesity and its consequences by directly modulating the thermogenesis and brown adipose tissue (BAT) function. The alamandine/MrgD metabolic effects and signaling remain unexplored. In this context, the main goal of the present study was to assess the metabolic consequences of MrgD genetic ablation in C57BL6/J mice by evaluating brown adipose tissue RNA sequencing. The main results showed that MrgD-KO mice have diminished brown adipose tissue and that a high-glucose diet (HG) decreased both circulating alamandine levels and MrgD expression in BAT from wild-type mice (WT). BAT transcriptome reveals that MrgD-KO HG mice regulated 45 genes, while WT HG mice regulated 1,148 genes. MrgD-KO mice fed a standard diet (ST) compared with WT ST mice regulated 476 genes, of which 445 genes were downregulated. BAT uses the MrgD receptor to display a normal pattern of gene expression and to respond, like WT mice, to an HG diet. In conclusion, the MrgD signaling is important for the metabolic regulation and manutention of BAT functionality.

Transgenic rat with overproduction of ubiquitous angiotensin-(1-7) presents neuroprotection in a model of ischemia and reperfusion.

Recent studies showed that angiotensin-(1-7) has cerebroprotective actions in stroke. In the present study, we aim to test whether tissue overexpression of Angiotensin-(1-7), mainly in the brain provides neuroprotection in a model of ischemia/reperfusion by bilateral common carotid arteries occlusion/reperfusion (BCCAo/R). Evaluation of neurological deficit scores and bilateral asymmetry test (BAT) were performed seven days after transient BCCAo/R in transgenic rats (TG-7371) overexpressing Angiotensin-(1-7) and Sprague-Dawley (SD) rats. To assess blood-brain barrier (BBB) permeability Evans blue dye (EB) was intravenously injected. Cytokine levels were quantified in the whole brain through Elisa assay and oxidative stress was measured 7 days after ischemia. The expression of AT1 and Mas receptors and inducible nitric oxide synthase (iNOS) was evaluated by RT-PCR. Neurological deficits were observed in both SD-BCCAo/R and TG-BCCAo/R, contrasting to sham-operated groups. However, TG-BCCAo/R showed a significant lower neurological score and latency in BAT when compared with SD-BCCAo/R. BBB integrity in TG-BCCAo/R was improved, since these animals showed lower extravasation of EB than SD-BCCAo/R. Interestingly, TG-BCCAo/R presented lower levels of pro-inflammatory cytokines when compared to SD-BCCAo/R. Levels of IL-10 were higher in SD-BCCAo/R than in SD control and even higher in TG-BCCAo/R. TG-BCCAo/R animals presented decreased levels of TBARS and increase in SOD activity and GSH levels when compared to SD sham rats. RT-PCR results showed higher levels of AT1 receptor and iNOS in SD-BCCAo/R compared to TG-BCCAo/R, but no difference was observed for Mas receptor. The present study shows that lifetime increase in cerebral expression of an Ang-(1-7)-producing fusion protein induces neuroprotection in experimental global cerebral ischemia and reperfusion, reassuring that, pharmacological strategies leading to increase in Ang-(1-7) can be an additional tool for stroke therapy.

Impact of genetic deletion of MrgD or Mas receptors in depressive-like behaviour in mice.

OBJECTIVES: To evaluate the impact of genetic deletion of receptors of the counterregulatory arms of the renin-angiotensin system in depressive-like behaviours. METHODS: 8-12 weeks-old male mice wild type (WT, C57BL/6J) and mice with genetic deletion of MrgD (MrgD KO) or Mas receptors (Mas KO) were subjected to the Forced Swim Test (FST) and the Tail Suspension Test (TST). Brain-derived neurotrophic factor (BDNF) levels were measured by enzyme-linked immunosorbent assay (ELISA). Blockade of Mas was performed by acute intracerebroventricular (icv) injection of its selective antagonist, A779. RESULTS: No statistical difference in immobility time was observed between MrgD KO and WT male animals subjected to FST and TST. However, acute icv injection of A779 significantly increased the immobility time of MrgD KO male mice subjected to FST and TST, suggesting the involvement of Mas in preventing depressive-like behaviour. Indeed, Mas KO male animals showed increased immobility time in FST and TST, evidencing a depressive-like behaviour in these animals, in addition to a reduction in BDNF levels in the prefrontal cortex and hippocampus. No changes in BDNF levels were observed in MrgD KO male animals. CONCLUSION: Our data showed that Mas plays an important role in the neurobiology of depression probably by modulating BDNF expression. On the contrary, lack of MrgD did not alter depressive-like behaviour, which was supported by the lack of alterations in BDNF levels.

Quantitative Phosphoproteomics of the Angiotensin AT2-Receptor Signaling Network Identifies HDAC1 (Histone-Deacetylase-1) and p53 as Mediators of Antiproliferation and Apoptosis.

BACKGROUND: Angiotensin AT2-receptor signaling is atypical for a G-protein coupled receptor and incompletely understood. To obtain novel insights into AT2-receptor signaling, we mapped changes in the phosphorylation status of the entire proteome of human aortic endothelial cells in response to AT2-receptor stimulation. METHODS: Phosphorylation status of human aortic endothelial cells after stimulation with C21 (1 µM; 0, 1, 3, 5, 20 minutes) was determined utilizing time-resolved quantitative phosphoproteomics. Specific changes in protein phosphorylation and acetylation were confirmed by Western Blotting. Functional tests included resazurin assay for cell proliferation, and caspase 3/7 luminescence assay or FACS analysis of annexin V expression for apoptosis. RESULTS: AT2-receptor stimulation significantly altered the phosphorylation status of 172 proteins (46% phosphorylations, 54% dephosphorylations). Bioinformatic analysis revealed a cluster of phospho-modified proteins involved in antiproliferation and apoptosis. Among these proteins, HDAC1 (histone-deacetylase-1) was dephosphorylated at serine421/423 involving serine/threonine phosphatases. Resulting HDAC1 inhibition led to p53 acetylation and activation. AT2-receptor stimulation induced antiproliferation and apoptosis, which were absent when cells were co-incubated with the p53 inhibitor pifithrin-α, thus indicating p53-dependence of these AT2-receptor mediated functions. CONCLUSIONS: Contrary to the prevailing view that AT2-receptor signaling largely involves phosphatases, our study revealed significant involvement of kinases. HDAC1 inhibition and resulting p53 activation were identified as novel, AT2-receptor coupled signaling mechanisms. Furthermore, the study created an openly available dataset of AT2-receptor induced phospho-modified proteins, which has the potential to be the basis for further discoveries of currently unknown, AT2-receptor coupled signaling mechanisms.

Pattern ERGs suggest a possible retinal contribution to the visual acuity loss in acute optic neuritis.

PURPOSE: Macular involvement in optic neuritis (ON) is well-recognised but poorly understood and may be of clinical relevance. This study explores macular structure-function correlates in acute ON. METHODS: This cross-sectional cohort study recruited ON patients within 14 days of symptom onset. Subjects underwent pattern electroretinography (PERG), pattern visual evoked potentials (PVEP) and optical coherence tomography (OCT) imaging. PERG P50 and N95 components were correlated with OCT data. RESULTS: Twenty-six individuals with ON were recruited, comprising eleven multiple sclerosis (MS-ON), six myelin oligodendrocyte glycoprotein associated (MOG-ON) and nine with isolated ON. These were compared with 28 healthy controls. PVEPs were undetectable in 11 (42%) of individuals with ON. When detectable, PVEP P100 was delayed (median 136 ms range 110-173 ms) and amplitude reduced (median 6 µV, range 3-14 µV) in ON compared with controls (both p < 0.001). PERG P50 component amplitudes, largely reflecting macular function, were reduced in affected eyes (median 2.3 µV; range 0.8-5.0 µV) compared with controls (3.3 µV; range 2.8-5.7 µV) and compared with fellow eyes (p < 0.001). The N95:P50 ratio was below the reference range in the affected eyes of five patients. Eight cases (32%) had subnormal P50 amplitudes (< 2.0 µV), and these patients had poorer visual acuity (p = 0.020). P50 amplitudes were positively correlated with an increase in inner nuclear layer thickness (rs = 0.36; p = 0.009) and macular ganglion cell and inner plexiform layer (mGCIPL) thickness (rs = 0.44, p = 0.022). CONCLUSION: PERG P50 component reduction reveals dysfunction of inner macular layers in acute ON and correlates with structural alterations on OCT. These early macular pathologic processes are likely to contribute to the visual loss.

Angiotensin 1-7 in severe COVID-19 patients: a phase 1 clinical trial

BackgroundThe coronavirus-related disease (COVID-19) is mainly characterized by a respiratory involvement, with few available therapeutics for critically cases. The renin-angiotensin system (RAS) has a relevant role in the pathogenesis of COVID-19, as the virus enter hosts cells via the angiotensin-converting enzyme 2 (ACE2) and RAS disequilibrium promote inflammation and fibrosis. Exogenous angiotensin-(1-7) might modulate RAS in COVID-19 patients; however, no data on its safety are available in this setting. MethodsThis investigator-initiated, open label, phase I clinical trial was conducted to test the safety of intravenous administration of Angiotensin-(1-7) in severe COVID-19 patients admitted in two intensive care units (ICU) in Belo Horizonte, Brazil. In addition to standard of care, intravenous administration of Angiotensin-(1-7) was started at 5 mcg/Kg*day and increased to 10 mcg/Kg*day after 24 hours and continued for a maximum of 7 days or until ICU discharge. The rate of serious adverse events (SAEs) served as the primary outcome of the study. ResultsBetween August and December 2020, 28 patients were included (mean age of 55.8{+/-}12.0 years). All but one patient underwent dose escalation after 24 hours and 8 (28.5%) received the treatment until day 7. No significant differences in mean blood pressure and heart rate were observed before and after the initiation of the drug. During the period of intervention, 5/28 (17.8%) patients required vasopressors, 4 at low dose norepinephrine (i.e. <0.05 mcg/kg*min), while one patient required higher doses because of septic shock. One patient presented with sinus bradycardia, which was considered possibly related to the study drug and resolved after discontinuation. Six patients (21.4%) died before ICU discharge. ConclusionsIntravenous infusion of Angiotensin-(1-7) up to 10 mcg/Kg*day was safe in severe COVID-19 patients and could represent a potential therapeutic strategy in this setting. Trial RegistrationRegistro Brasileiro de Ensaios Clinicos, UTN code: U1111-1255-7167, registered on 08/05/2020; ClinicalTrials.gov Identifier: NCT04633772; retrospectively registered on November 18 2020

Physical activity reduces intradermal bacterial load in a murine model submitted to forced swim training - a pilot study.

Regular exercise is beneficial to health. This study evaluated the effects of moderate and intense physical exercise modalities on intradermal infection by Staphylococcus aureus in a murine model. Mice that practiced moderate exercise had lower bacterial load on lymph nodes and less inflammatory infiltrate in dermis. They presented greater weight, however, less amount of epididymal fat: the weight was increased while they had fat diminished. A positive correlation was observed between lipid content and bacterial load in mice trained at moderate intensity. Animals that were under high intensity exercises presented superior bacterial load on the lymph nodes, increased neutrophil count and circulating lymphocytes, and had leukocyte recruitment to the dermis augmented, when compared to the ones in moderate exercise. These findings suggest that moderate physical activity modulates the immune response in dermal infection caused by S. aureus in a murine model.

Variability of retinopathy consequent upon novel mutations in LAMA1.

PURPOSE: Bi-allelic mutations in LAMA1 (laminin 1) (OMIM # 150320) cause Poretti-Boltshauser Syndrome (PTBHS), a rare non-progressive cerebellar dysplasia disorder with ophthalmic manifestations including oculomotor apraxia, high myopia, and retinal dystrophy. Only 38 variants, nearly all loss of function have been reported. Here, we describe novel LAMA1 variants and detailed retinal manifestations in two unrelated families. METHODS: Whole-genome sequencing was conducted on three siblings of a consanguineous family with myopia and retinal dystrophy and on a child from an unrelated non-consanguineous couple. Clinical evaluation included full ophthalmic examination, detailed colour, autofluorescence retinal imaging, retinal optical coherence tomography (OCT), fluorescein angiography under anesthesia, and pattern and full-field electroretinography. RESULTS: Genetic analysis revealed a novel homozygous LAMA1 frameshift variant, c.1492del p.(Arg498Glyfs *25), in the affected siblings in family 1 and a novel frameshift c.3065del p.(Gly1022Valfs *2) and a deletion spanning exons 17-23 in an unrelated individual in family 2. Two of the three siblings and the unrelated child had oculomotor apraxia in childhood; none of the siblings had symptoms of other neurological dysfunction as adults. All four had myopia. The affected siblings had a qualitatively similar retinopathy of wide-ranging severity. The unrelated patient had a severe abnormality of retinal vascular development, which resulted in vitreous haemorrhage and neovascular glaucoma in the left eye and a rhegmatogenous retinal detachment in the right eye. CONCLUSIONS: This report describes the detailed retinal structural and functional consequences of LAMA1 deficiency in four patients from two families, and these exhibit significant variability with evidence of both retinal dystrophy and abnormal and incomplete retinal vascularisation.

Reshaping the Preterm Heart: Shifting Cardiac Renin-Angiotensin System Towards Cardioprotection in Rats Exposed to Neonatal High-Oxygen Stress.

BACKGROUND: Approximately 10% of infants are born preterm. Preterm birth leads to short and long-term changes in cardiac shape and function. By using a rat model of neonatal high-oxygen (80%O2) exposure, mimicking the premature hyperoxic transition to the extrauterine environment, we revealed a major role of the renin-angiotensin system peptide Angio II (angiotensin II) and its receptor AT1 (angiotensin receptor type 1) on neonatal O2-induced cardiomyopathy. Here, we tested whether treatment with either orally active compounds of the peptides Angio-(1-7) or alamandine included in cyclodextrin could prevent postnatal cardiac remodeling and the programming of cardiomyopathy induced by neonatal high-O2 exposure. METHODS: Sprague-Dawley pups were exposed to room air or 80% O2 from postnatal day 3 (P3) to P10. Neonatal rats were treated orally from P3 to P10 and assessed at P10 and P28. Left ventricular (LV) shapes were characterized by tridimensional computational atlases of ultrasound images in addition to histomorphometry. RESULTS: At P10, high O2-exposed rats presented a smaller, globular and hypertrophied LV shape versus controls. Treatment with cyclodextrin-Angio-(1-7) significantly improved LV function in the O2-exposed neonatal rats and slightly changed LV shape. Cyclodextrin-alamandine and cyclodextrin-Angio-(1-7) treatments similarly reduced hypertrophy at P10 as well as LV remodeling and dysfunction at P28. Both treatments upregulated cardiac angiotensin-converting enzyme 2 in O2-exposed rats at P10 and P28. CONCLUSIONS: Our findings demonstrate LV remodeling changes induced by O2-stress and the potential benefits of treatments targeting the cardioprotective renin-angiotensin system axis, supporting the neonatal period as an important window for interventions aiming at preventing cardiomyopathy in people born preterm.

Plasma copeptin is increased and associated with smaller kidney volume in young adults born very preterm.

Background: Plasma copeptin, a surrogate marker for vasopressin levels, is increased in neonates born preterm, particularly in those with a more severe neonatal course, as reflected by bronchopulmonary dysplasia. Copeptin levels in adulthood are unknown. Methods: In this case-control study of 101 adults born very preterm (<30 weeks of gestation) and 105 control adults born full-term, a comprehensive clinical and biological assessment was performed, including blood pressure measurements, kidney ultrasound and determination of plasma copeptin, renin activity, angiotensin II, aldosterone, apelin, sodium and potassium, serum and morning urine osmolality. Results: The median age in the study was 23.1 years [interquartile range (IQR) 21.2-24.8] and 57% were females. In males, the median copeptin levels were 8.2 pmol/L (IQR 6.3-12.4) and 6.1 pmol/L (IQR 4.3-9.0) in the preterm and term groups, respectively (P = 0.022). In females, the median copeptin levels were 5.2 pmol/L (IQR 3.9-7.6) and 4.0 pmol/L (IQR 2.8-5.7) in the preterm and term groups, respectively (P = 0.005). Adults born preterm with a history of bronchopulmonary dysplasia had further increased copeptin levels. The kidney volume, adjusted for height, was smaller and albuminuria was higher in the preterm group, and both were associated with higher plasma copeptin levels. Conclusions: Plasma copeptin is higher in young adults born preterm and is related to a more severe neonatal course and smaller kidney volume.

Alamandine Induces Neuroprotection in Ischemic Stroke Models.

BACKGROUND AND OBJECTIVE: Stroke, a leading cause of mortality and disability, characterized by neuronal death, can be induced by a reduction or interruption of blood flow. In this study, the role of Alamandine, a new peptide of the renin-angiotensin system, was evaluated in in-vitro and in-vivo brain ischemia models. METHODS: In the in-vitro model, hippocampal slices from male C57/Bl6 mice were placed in a glucose-free aCSF solution and bubbled with 95% N2 and 5% CO2 to mimic brain ischemia. An Alamandine concentration-response curve was generated to evaluate cell damage, glutamatergic excitotoxicity, and cell death. In the in-vivo model, cerebral ischemia/ reperfusion was induced by bilateral occlusion of common carotid arteries (BCCAo-untreated) in SD rats. An intracerebroventricular injection of Alamandine was given 20-30 min before BCCAo. Animals were subjected to neurological tests 24 h and 72 h after BCCAo. Cytokine levels, oxidative stress markers, and immunofluorescence were assessed in the brain 72 h after BCCAo. RESULTS: Alamandine was able to protect brain slices from cellular damage, excitotoxicity and cell death. When the Alamandine receptor was blocked, protective effects were lost. ICV injection of Alamandine attenuated neurological deficits of animals subjected to BCCAo and reduced the number of apoptotic neurons/cells. Furthermore, Alamandine induced anti-inflammatory effects in BCCAo animals as shown by reductions in TNFα, IL- 1ß, IL-6, and antioxidant effects through attenuation of the decreased SOD, catalase, and GSH activities in the brain. CONCLUSION: This study showed, for the first time, a neuroprotective role for Alamandine in different ischemic stroke models.

Genetic deletion of Mas receptor in FVB/N mice impairs cardiac use of glucose and lipids.

Angiotensin-(1-7) is a biologically active product of the renin-angiotensin system cascade and exerts inhibitory effects on inflammation, vascular and cellular growth mechanisms signaling through the G protein-coupled Mas receptor. The major purpose of the present study was to investigate the use of glucose and fatty acids by cardiac tissue in Mas knockout mice models. Serum levels of glucose, lipids, and insulin were measured in Mas-deficient and wild-type FVB/N mice. To investigate the cardiac use of lipids, the lipoprotein lipase, the gene expression of peroxisome proliferator-activated receptor alpha; carnitine palmitoyltransferase I and acyl-CoA oxidase were evaluated. To investigate the cardiac use of glucose, the insulin signaling through Akt/GLUT4 pathway, glucose-6-phosphate (G-6-P) and fructose-6-phosphate (F-6-P) glycolytic intermediates, in addition to ATP, lactate and the glycogen content were measured. Despite normal body weight, cholesterol and insulin, Mas-Knockout mice presented hyperglycemia and hypertriglyceridemia, impaired insulin signaling, through reduced phosphorylation of AKT and decreased translocation of GLUT4 in response to insulin, with subsequent decrease of the cardiac G-6-P and F-6-P. Lactate production and glycogen content were not altered in Mas-KO hearts. Mas-KO presented reduced cardiac lipoprotein lipase activity and decreased translocation of CD36 in response to insulin. The expression of peroxisome proliferator-activated receptor alpha and carnitine palmitoyltransferase I genes were lower in Mas-KO animals compared to wild-type animals. The ATP content of Mas-KO hearts was smaller than in wild-type. The present results suggest that genetic deletion of Mas produced a devastating effect on cardiac use of glucose and lipids, leading to lower energy efficiency in the heart.

Diminazene Aceturate, an angiotensin converting enzyme 2 (ACE2) activator, promotes cardioprotection in ischemia/reperfusion-induced cardiac injury.

This study aimed to investigate whether the Diminazene Aceturate (DIZE), an angiotensin-converting enzyme 2 (ACE2) activator, can revert cardiac dysfunction in ischemia reperfusion-induced (I/R) injury in animals and examine the mechanism underlying this effect. Wistar rats systemically received DIZE (1 mg/kg) for thirty days. Cardiac function in isolated rat hearts was evaluated using the Langendorff technique. After I/R, ventricular non-I/R and I/R samples were used to evaluate ATP levels. Mitochondrial function was assessed using cardiac permeabilized fibers and isolated cardiac mitochondria. Cardiac cellular electrophysiology was evaluated using the patch clamp technique. DIZE protected the heart after I/R from arrhythmia and cardiac dysfunction by preserving ATP levels, independently of any change in coronary flow and heart rate. DIZE improved mitochondrial function, increasing the capacity for generating ATP and reducing proton leak without changing the specific citrate synthase activity. The activation of the ACE2 remodeled cardiac electrical profiles, shortening the cardiac action potential duration at 90 % repolarization. Additionally, cardiomyocytes from DIZE-treated animals exhibited reduced sensibility to diazoxide (KATP agonist) and a higher KATP current compared to the controls. DIZE was able to improve mitochondrial function and modulate cardiac electrical variables with a cardio-protective profile, resulting in direct myocardial cell protection from I/R injury.