The renin-angiotensin system (RAS) plays a pivotal role in the pathogenesis of cardiovascular diseases. New members of this system have been characterized and shown to have biologically relevant actions. Alamandine and its receptor MrgD are recently identified components of RAS. In the cardiovascular system, alamandine actions included vasodilation, antihypertensive, and antifibrosis effects. Currently, the actions of alamandine on cardiomyocytes are unknown. Here our goal was twofold: 1) to unravel the signaling molecules activated by the alamandine/MrgD axis in cardiomyocytes; and 2) to evaluate the ability of this axis to prevent angiotensin II (ANG II)-induced hypertrophy. In cardiomyocytes from C57BL/6 mice, alamandine treatment induced an increase in nitric oxide (NO) production, which was blocked by d-Pro-ANG-(1-7), a MrgD antagonist. This NO rise correlated with increased phosphorylation of AMPK. Alamandine-induced NO production was preserved in Mas myocytes and lost in MrgD cells. Binding of fluorescent-labeled alamandine was observed in wild-type cells, but it was dramatically reduced in MrgD myocytes. We also assessed the consequences of prolonged alamandine exposure to cultured neonatal rat cardiomyocytes (NRCMs) treated with ANG II. Treatment of NRCMs with alamandine prevented ANG II-induced hypertrophy. Moreover, the antihypertrophic actions of alamandine were mediated via MrgD and NO, since they could be prevented by d-Pro-ANG-(1-7) or inhibitors of NO synthase or AMPK. β-Alanine, a MrgD agonist, recapitulated alamandine's cardioprotective effects in cardiomyocytes. Our data show that alamandine via MrgD induces AMPK/NO signaling to counterregulate ANG II-induced hypertrophy. These findings highlight the therapeutic potential of the alamandine/MrgD axis in the heart.

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The cardiac circadian clock is responsible for the modulation of different myocardial processes, and its dysregulation has been linked to disease development. How this clock machinery is regulated in the heart remains an open question. Because noradrenaline (NE) can act as a zeitgeber in cardiomyocytes, we tested the hypothesis that adrenergic signaling resets cardiac clock gene expression in vivo. In its anti-phase with Clock and Bmal1, cardiac Per1 abundance increased during the dark phase, concurrent with the rise in heart rate and preceded by an increase in NE levels. Sympathetic denervation altered Bmal1 and Clock amplitude, while Per1 was affected in both amplitude and oscillatory pattern. We next treated mice with a β-adrenergic receptor (β-AR) blocker. Strikingly, the β-AR blockade during the day suppressed the nocturnal increase in Per1 mRNA, without altering Clock or Bmal1. In contrast, activating β-AR with isoproterenol (ISO) promoted an increase in Per1 expression, demonstrating its responsiveness to adrenergic

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The renin-angiotensin system (RAS) is a classical hormonal system involved in a myriad of cardiovascular functions. This system is composed of many different peptides that act in the heart through different receptors. One of the most important of these peptides is Angiotensin II, which in pathological conditions triggers a set of actions that lead to heart failure. On the other hand, another RAS peptide, Angiotensin-(1-7) is well known to develop powerful therapeutic effects in many forms of cardiac diseases. In the last decade, two new components of RAS were described, the heptapeptide Alamandine and its receptor, the Mas-related G protein-coupled receptor member D (MrgD). Since then, great effort was made to characterize their physiological and pathological function in the heart. In this review, we summarize the latest insights about the actions of Alamandine/MrgD axis in the heart, with particular emphasis in the cardiomyocyte. More specifically, we focused on their anti-hypertrophic and contractility effects, and the related molecular events activated in the cardiomyocyte.

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It is well known that cholinergic hypofunction contributes to cardiac pathology; yet, the mechanisms involved remain unclear. Our previous publication has shown that genetically engineered model of cholinergic deficit, the vesicular acetylcholine transporter knockdown homozygous (VAChT KDHOM) mice exhibit pathological cardiac remodeling and a gradual increase in cardiac mass with aging. Given that an increase in cardiac mass is often caused by adrenergic hyperactivity, we hypothesized that VAChT KDHOM mice might have an increase in cardiac norepinephrine (NE) levels. We thus investigated the temporal changes in NE content in the heart from 3, 6 and 12 month-old VAChT mutants. Interestingly, mice with cholinergic hypofunction showed a gradual elevation in cardiac NE content, which was already increased at 6 months of age. Consistent with this finding, 6 month-old VAChT KDHOM mice showed enhanced sympathetic activity and a greater abundance of tyrosine hydroxylase positive sympathetic nerves in the heart. VAChT mutants exhibited an increase in peak calcium transient, and mitochondrial oxidative stress in cardiomyocytes along with enhanced GRK5 and NFAT staining in the heart. These are known targets of adrenergic signaling in the cell. Moreover, vagotomized-mice displayed an increase in cardiac NE content confirming the data obtained in VAChT KDHOM mice. Establishing a causal relationship between acetylcholine and NE, VAChT KDHOM mice treated with pyridostigmine, a cholinesterase inhibitor, showed reduced cardiac NE content, rescuing the phenotype. Our findings unveil a yet unrecognized role of cholinergic signaling as a modulator of cardiac NE, providing novel insights into the mechanisms that drive autonomic imbalance.

Introduction: Osteoarthritis is a disease that affects millions of Brazilians.Therapeutic ultrasound has been used in its treatment, either alone or associated with drugs. Objective: The aim of this study was to evaluate the effects of ultrasound (US) associated with Copaiba oil (CO) on knee osteoarthritis. Methods: Patients were divided into three different groups: US, US+CO, CO.Ten treatment sessions were held twice a week, 30 minutes each.Pain intensity was assessed through the Visual Analog Scale (VAS) and Range of Motion (ROM) by goniometry, and muscle strength was assessed by means of the Medical Research Council Scale. Statistical analysis was performed by Cohen’s d test, student’s t test and ANOVA, considering p<0.05 as significant. Results: Pain reduced in all groups.The US+CO group (d = -3.50) presented larger effect size when compared to the other groups. Regarding ROM, the largest effect size was observed in the US+CO group for flexion (d = 0.86) and extension (d = 0.97) in comparison with the remainder groups. Muscle strength increased in the US (d = 1.54) and US+CO (d = 1.60) groups for flexion.Regarding extension, the US group presented the largest effect size (d = 1.80). Conclusion: Therapeutic ultrasound associated with copaiba oil is a practical and effective therapy for the treatment of inflammatory diseases such as osteoarthritis.