Antinociceptive Effect of the Combination of a Novel α4ß2* Agonist with Donepezil in a Chronic Pain Model.

Chronic pain presents a major challenge in contemporary medicine, given the limited effectiveness and numerous adverse effects linked to available treatments. Recognizing the potential of the cholinergic pathway as a therapeutic target, the present work evaluates the antinociceptive activity of a combination of Cris-104, a novel α4ß2* receptor agonist, and donepezil, a central anticholinesterase agent. Isobolographic analysis revealed that equimolar combination was approximately 10 times more potent than theoretically calculated equipotent additive dose. Administration of Cris-104 and donepezil combination (3 µmol/kg) successfully reversed hyperalgesia and mechanical allodynia observed in rats subjected to spinal nerve ligation (SNL). The combination also modulated neuroinflammation by reducing astrocyte activation, evident in the decreased expression of glial fibrillary acidic protein (GFAP) in the spinal cord. The observed synergism in combining a nicotinic receptor agonist with an anticholinesterase agent underscores its potential for treating chronic pain. This alternative therapeutic distinct advantage, including dose reduction and high selectivity for the receptor, contribute to a more favorable profile with minimized adverse effects.

Heart Failure in Menopause: Treatment and New Approaches.

Aging is an important risk factor for the development of heart failure (HF) and half of patients with HF have preserved ejection fraction (HFpEF) which is more common in elderly women. In general, sex differences that lead to discrepancies in risk factors and to the development of cardiovascular disease (CVD) have been attributed to the reduced level of circulating estrogen during menopause. Estrogen receptors adaptively modulate fibrotic, apoptotic, inflammatory processes and calcium homeostasis, factors that are directly involved in the HFpEF. Therefore, during menopause, estrogen depletion reduces the cardioprotection. Preclinical menopause models demonstrated that several signaling pathways and organ systems are closely involved in the development of HFpEF, including dysregulation of the renin-angiotensin system (RAS), chronic inflammatory process and alteration in the sympathetic nervous system. Thus, this review explores thealterations observed in the condition of HFpEF induced by menopause and the therapeutic targets with potential to interfere with the disease progress.

Mesenchymal Stem Cell Therapy in Diabetic Cardiomyopathy.

The incidence and prevalence of diabetes mellitus (DM) are increasing worldwide, and the resulting cardiac complications are the leading cause of death. Among these complications is diabetes-induced cardiomyopathy (DCM), which is the consequence of a pro-inflammatory condition, oxidative stress and fibrosis caused by hyperglycemia. Cardiac remodeling will lead to an imbalance in cell survival and death, which can promote cardiac dysfunction. Since the conventional treatment of DM generally does not address the prevention of cardiac remodeling, it is important to develop new alternatives for the treatment of cardiovascular complications induced by DM. Thus, therapy with mesenchymal stem cells has been shown to be a promising approach for the prevention of DCM because of their anti-apoptotic, anti-fibrotic and anti-inflammatory effects, which could improve cardiac function in patients with DM.

ROCK Inhibition as Potential Target for Treatment of Pulmonary Hypertension.

Pulmonary hypertension (PH) is a cardiovascular disease caused by extensive vascular remodeling in the lungs, which ultimately leads to death in consequence of right ventricle (RV) failure. While current drugs for PH therapy address the sustained vasoconstriction, no agent effectively targets vascular cell proliferation and tissue inflammation. Rho-associated protein kinases (ROCKs) emerged in the last few decades as promising targets for PH therapy, since ROCK inhibitors demonstrated significant anti-remodeling and anti-inflammatory effects. In this review, current aspects of ROCK inhibition therapy are discussed in relation to the treatment of PH and RV dysfunction, from cell biology to preclinical and clinical studies.

Estrogen Receptors: Therapeutic Perspectives for the Treatment of Cardiac Dysfunction after Myocardial Infarction.

Estrogen receptors (ER) mediate functions beyond their endocrine roles, as modulation of cardiovascular, renal, and immune systems through anti-inflammatory and anti-apoptotic effects, preventing necrosis of cardiomyocytes and endothelial cells, and attenuating cardiac hypertrophy. Estradiol (E2) prevents cardiac dysfunction, increases nitric oxide synthesis, and reduces the proliferation of vascular cells, yielding protective effects, regardless of gender. Such actions are mediated by ER (ER-alpha (ERα), ER-beta (ERß), or G protein-coupled ER (GPER)) through genomic or non-genomic pathways, which regulate cardiovascular function and prevent tissue remodeling. Despite the extensive knowledge on the cardioprotective effects of estrogen, clinical studies conducted on myocardial infarction (MI) and cardiovascular diseases still include favorable and unfavorable profiles. The purpose of this review is to provide up-to-date information regarding molecular, preclinical, and clinical aspects of cardiovascular E2 effects and ER modulation as a potential therapeutic target for the treatment of MI-induced cardiac dysfunction.

SAXS signature of the lamellar ordering of ionic domains of perfluorinated sulfonic-acid ionomers by electric and magnetic field-assisted casting.

At present, small angle X-ray scattering (SAXS) studies of perfluorinated sulfonic-acid ionomers (PFSAs) are unable to fully determine the true shape of their building blocks, as recent SAXS modelling predicts disk- and rod-like nanoionic domains as being equally possible. This scenario requires evidence-based findings to unravel the real shape of PFSA building blocks. Herein, a SAXS pattern signature for a lamellar nanophase separation of the ionic domains of Nafion is presented, backed by mid and far infrared spectroscopy (MIR and FIR) and wide angle X-ray scattering (WAXS) data of Nafion in different ionic forms, a broad range of ionic phase contents (EW ∼ 859-42 252 g eq-1) and temperatures. The study indicates that the lamellar arrangement of the ionic domains is the most representative morphology that accounts for the physical properties of this ionomer. The lamellar SAXS reflections of Nafion are enhanced in electric and magnetic field-aligned membranes, as confirmed by atomic force microscopy (AFM). Electric and magnetic field-assisted casting of Nafion allowed producing nanostructured and anisotropic films with the lamellas stacked perpendicularly to the field vector, which is the direction of interest for several applications. Such nanostructured Nafion membranes are bestowed with advanced optical and proton transport properties, making them promising materials for solar and fuel cells.

Reduction of cardiac and renal dysfunction by new inhibitor of DPP4 in diabetic rats.

BACKGROUND: Increased mortality due to type 2 diabetes mellitus (T2DM) has been associated with renal and/or cardiovascular dysfunction. Dipeptidyl dipeptidase-4 inhibitors (iDPP-4s) may exert cardioprotective effects through their pleiotropic actions via glucagon-like peptide 1-dependent mechanisms. In this study, the pharmacological profile of a new iDPP-4 (LASSBio-2124) was investigated in rats with cardiac and renal dysfunction induced by T2DM. METHODS: T2DM was induced in rats by 2 weeks of a high-fat diet followed by intravenous injection of streptozotocin. Metabolic disturbance and cardiac, vascular, and renal dysfunction were analyzed in the experimental groups. RESULTS: Sitagliptin and LASSBio-2124 administration after T2DM induction reduced elevated glucose levels to 319.8 ±â€¯13.2 and 279.7 ±â€¯17.8 mg/dL, respectively (p < 0.05). LASSBio-2124 also lowered the cholesterol and triglyceride levels from 76.8 ±â€¯8.0 to 42.7 ±â€¯3.2 mg/dL and from 229.7 ±â€¯25.4 to 100.7 ±â€¯17.1 mg/dL, in diabetic rats. Sitagliptin and LASSBio-2124 reversed the reduction of the plasma insulin level. LASSBio-2124 recovered the increased urinary flow in diabetic animals and reduced 24-h proteinuria from 23.7 ±â€¯1.5 to 13.3 ±â€¯2.8 mg (p < 0.05). It also reduced systolic and diastolic left-ventricular dysfunction in hearts from diabetic rats. CONCLUSION: The effects of LASSBio-2124 were superior to those of sitagliptin in the cardiovascular systems of T2DM rats. This new prototype showed promise for the avoidance of comorbidities in a T2DM experimental model, and thus may constitute an innovative therapeutic agent for the treatment of these conditions in the clinical field in future.

G-Protein-Coupled Estrogen Receptor Agonist G1 Improves Diastolic Function and Attenuates Cardiac Renin-Angiotensin System Activation in Estrogen-Deficient Hypertensive Rats.

This study was aimed to clarify differences in how specific agonists of the 3 estrogen receptors (ERs) influence diastolic function and the renin-angiotensin system (RAS) after ovariectomy (OVX) in 24 female spontaneously hypertensive rat (SHR) undergoing bilateral OVX at 12 weeks of age. Eight weeks after surgery, rats were randomized (n = 6/group) to receive equipotent, daily treatments of one of the ER agonists (ERα agonist, propyl pyrazole trisphenol 94 µg/kg; ERß agonist, diarylpropionitrile 58 µg/kg; G-protein-coupled estrogen receptor [GPER] agonist, G1 100 µg/kg), or vehicle (peanut oil). After 4 weeks of treatment, left ventricular function/structure and systemic/intracardiac pressure measurements were obtained by echocardiography and a fluid-filled catheter attached to a pressure transducer, respectively. Selective ER agonist treatment with G1 or propyl pyrazole trisphenol led to improvements in diastolic function after estrogen loss when compared with vehicle-treated OVX rats. Although mean arterial blood pressure was not overtly different among groups, chronic G1, but not the other ER ligands, enhanced the in vitro vasorelaxant responsiveness to acetylcholine in aortic rings. These favorable effects of G1 were further linked to reductions in cardiac angiotensin-converting enzyme activity, AT1R protein expression, and Ang II immunoreactivity. Activation of ERß had no effect on cardiac function and did not alter components of the canonical cardiac RAS in comparison with vehicle-treated OVX SHR. These data imply that of the 3 ERs, GPER has a unique role in preserving diastolic function and favorably modulating the cardiac RAS independent of arterial pressure. Specifically, if GPER is pharmacologically activated, it could provide a therapeutic opportunity to limit the development and/or progression of diastolic dysfunction in hypertensive women after estrogen loss.

Mesenchymal stromal cell therapy reduces lung inflammation and vascular remodeling and improves hemodynamics in experimental pulmonary arterial hypertension.

BACKGROUND: Experimental research has reported beneficial effects of mesenchymal stromal cell (MSC) therapy in pulmonary arterial hypertension (PAH). However, these studies either were based on prophylactic protocols or assessed basic remodeling features without evaluating possible mechanisms. We analyzed the effects of MSC therapy on lung vascular remodeling and hemodynamics and its possible mechanisms of action in monocrotaline (MCT)-induced PAH. METHODS: Twenty-eight Wistar rats were randomly divided into two groups. In the PAH group, animals received MCT 60 mg/kg intraperitoneally, while a control group received saline (SAL) instead. On day 14, both groups were further randomized to receive 105 adipose-derived MSCs or SAL intravenously (n = 7/group). On day 28, right ventricular systolic pressure (RVSP) and the gene expression of mediators associated with apoptosis, inflammation, fibrosis, Smad-1 levels, cell proliferation, and endothelial-mesenchymal transition were determined. In addition, lung histology (smooth muscle cell proliferation and plexiform-like injuries), CD68+ and CD163+ macrophages, and plasma levels of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) were evaluated. RESULTS: In the PAH group, adipose-derived MSCs, compared to SAL, reduced mean RVSP (29 ± 1 vs 39 ± 2 mmHg, p < 0.001), lung tissue collagen fiber content, smooth muscle cell proliferation, CD68+ macrophages, interleukin-6 expression, and the antiapoptotic mediators Bcl-2 and survivin. Conversely, expression of the proapoptotic mediator procaspase-3 and plasma VEGF increased, with no changes in PDGF. In the pulmonary artery, MSCs dampened the endothelial-mesenchymal transition. CONCLUSION: In MCT-induced PAH, MSC therapy reduced lung vascular remodeling, thus improving hemodynamics. These beneficial effects were associated with increased levels of proapoptotic markers, mesenchymal-to-endothelial transition, reduced cell proliferation markers, and inflammation due to a shift away from the M1 phenotype.

Adenosine A2A receptor agonist prevents cardiac remodeling and dysfunction in spontaneously hypertensive male rats after myocardial infarction.

BACKGROUND: This work evaluated the hypothesis that 3,4-methylenedioxybenzoyl-2-thienylhydrazone (LASSBio-294), an agonist of adenosine A2A receptor, could be beneficial for preventing cardiac dysfunction due to hypertension associated with myocardial infarction (MI). METHODS: Male spontaneously hypertensive rats (SHR) were randomly divided into four groups (six animals per group): sham-operation (SHR-Sham), and myocardial infarction rats (SHR-MI) were treated orally either with vehicle or LASSBio-294 (10 and 20 mg.kg-1.d-1) for 4 weeks. Echocardiography and in vivo hemodynamic parameters measured left ventricle (LV) structure and function. Exercise tolerance was evaluated using a treadmill test. Cardiac remodeling was accessed by LV collagen deposition and tumor necrosis factor α expression. RESULTS: Early mitral inflow velocity was significantly reduced in the SHR-MI group, and there was significant recovery in a dose-dependent manner after treatment with LASSBio-294. Exercise intolerance observed in the SHR-MI group was prevented by 10 mg.kg-1.d-1 of LASS-Bio-294, and exercise tolerance exceeded that of the SHR-Sham group at 20 mg.kg-1.d-1. LV end-diastolic pressure increased after MI, and this was prevented by 10 and 20 mg.kg-1.d-1 of LASSBio-294. Sarcoplasmic reticulum Ca2+ ATPase levels were restored in a dose-dependent manner after treatment with LASSBio-294. Fibrosis and inflammatory processes were also counteracted by LASSBio-294, with reductions in LV collagen deposition and tumor necrosis factor α expression. CONCLUSION: In summary, oral administration of LASSBio-294 after MI in a dose-dependent manner prevented the development of cardiac dysfunction, demonstrating this compound's potential as an alternative treatment for heart failure in the setting of ischemic heart disease with superimposed chronic hypertension.

Effect of Age, Estrogen Status, and Late-Life GPER Activation on Cardiac Structure and Function in the Fischer344×Brown Norway Female Rat.

Age-associated changes in cardiac structure and function, together with estrogen loss, contribute to the progression of heart failure with preserved ejection fraction in older women. To investigate the effects of aging and estrogen loss on the development of its precursor, asymptomatic left ventricular diastolic dysfunction, echocardiograms were performed in 10 middle-aged (20 months) and 30 old-aged (30 months) female Fischer344×Brown-Norway rats, 4 and 8 weeks after ovariectomy (OVX) and sham procedures (gonads left intact). The cardioprotective potential of administering chronic G1, the selective agonist to the new G-protein-coupled estrogen receptor (GPER), was further evaluated in old rats (Old-OVX+G1) versus age-matched, vehicle-treated OVX and gonadal intact rats. Advanced age and estrogen loss led to decreases in myocardial relaxation and elevations in filling pressure, in part, due to reductions in phosphorylated phospholamban and increases in cardiac collagen deposition. Eight weeks of G-protein-coupled estrogen receptor activation in Old-OVX+G1 rats reversed the adverse effects of age and estrogen loss on myocardial relaxation through increases in sarcoplasmic reticulum Ca2+ ATPase expression and reductions in interstitial fibrosis. These findings may explain the preponderance of heart failure with preserved ejection fraction in older postmenopausal women and provide a promising, late-life therapeutic target to reverse or halt the progression of left ventricular diastolic dysfunction.

Oral treatment with Euterpe oleracea Mart. (açaí) extract improves cardiac dysfunction and exercise intolerance in rats subjected to myocardial infarction.

BACKGROUND: This study was designed to evaluate the cardioprotective effects of Euterpe oleracea Mart., popularly known as "açaí", on rats subjected to myocardial infarction (MI). METHODS: Hydroalcoholic extracts of açaí were obtained from a decoction of the seeds. Two male Wistar rat groups were delineated: 1) the sham-operated group (control, n = 6), with no surgical amendment, and 2) the MI group (n = 12), in which the anterior descendent coronary artery was occluded during surgery. MI group was divided into two subgroups, in which rats were either treated with hydroalcoholic extract of Euterpe oleracea seeds (100 mg/kg/day p.o.) or received no treatment. Treatment began on the day of surgery, and lasted 4 weeks. Subsequently, rats were subject to an exercise test protocol, hemodynamic evaluation, and histological analysis of the left ventricle. Groups were compared using one-way analysis of variance (ANOVA), followed by Dunnett's test. RESULTS: The total running distance of sham rats was 1339.0 ± 276.6 m, MI rats was 177.6 ± 15.8 m (P < 0.05), and MI-açaí rats was 969.9 ± 362.2 m. Systolic arterial pressure was significantly decreased in MI rats (86.88 ± 4.62 mmHg) compared to sham rats (115.30 ± 7.24 mmHg; P < 0.05). Açaí treatment prevented a reduction in systolic arterial pressure (130.00 ± 8.16 mmHg) compared to MI rats (P < 0.05). Left ventricular (LV) end-diastolic pressure was significantly augmented in MI rats (17.62 ± 1.21 mmHg) compared to sham rats (4.15 ± 1.60 mmHg; P < 0.05), but was 3.69 ± 2.69 mmHg in açaí-treated rats (P < 0.05 vs. MI). The LV relaxation rate (-dp/dt) was reduced in MI rats compared to the sham group, whereas açaí treatment prevented this reduction. Açaí treatment prevented cardiac hypertrophy and LV fibrosis in MI rats. CONCLUSIONS: Euterpe oleracea treatment of MI rats prevented the development of exercise intolerance, cardiac hypertrophy, fibrosis, and dysfunction.

LASSBio-294, A compound with inotropic and lusitropic activity, decreases cardiac remodeling and improves Ca²(+) influx into sarcoplasmic reticulum after myocardial infarction.

BACKGROUND: Myocardial infarction (MI) is commonly associated with cardiac hypertrophy, reduced Ca²(+) uptake into the sarcoplasmic reticulum (SR) and impaired myocardial relaxation. Treatment to prevent MI-associated complications is currently lacking. The purpose of the present study was to investigate the remodeling and function of hearts subjected to experimental MI and to evaluate the response to treatment with a new thienylhydrazone: 3,4-methylenedioxybenzoyl-2-thienylhydrazone (LASSBio-294), which has demonstrated positive inotropic properties. METHODS: LASSBio-294 (2 mg/kg) or vehicle (dimethyl sulfoxide) was administered daily by intraperitoneal injection for 4 weeks in sham-operated rats and rats with MI. Cardiac remodeling and hemodynamic parameters were monitored through histological and intraventricular pressure analyses. Intracellular Ca²(+) regulation (uptake and release) and the sensitivity of contractile proteins to Ca²(+) were evaluated by determining the contractile response of saponin-skinned cardiac cells from infarcted hearts. RESULTS: Cardiac hypertrophy occurred at 4 weeks post-MI and was partially reverted by treatment with LASSBio-294. LASSBio-294 treatment also reduced the nuclear density, collagen volume fraction, and left ventricular end-diastolic pressure (LV EDP) induced by MI. MI led to reduced Ca²(+) uptake from the SR, but did not modify the Ca²(+) release or the Ca²(+)-force relationship. LASSBio-294 restored SR function and enhanced the sensitivity of contractile proteins to Ca²(+). CONCLUSION: LASSBio-294 is a promising candidate for improving intracellular Ca²(+) regulation and preventing MI-induced cardiac dysfunction, which could potentially prevent heart failure (HF).

Pharmacological activation of liver X receptors promotes reverse cholesterol transport in vivo.

BACKGROUND: Liver X receptors (LXRs) are ligand-activated transcription factors involved in the control of lipid metabolism and inflammation. Synthetic LXR agonists have been shown to inhibit the progression of atherosclerosis in mice, but the mechanism is uncertain. LXR agonism upregulates the genes encoding ATP binding cassette transporters A1 (ABCA1) and G1 (ABCG1) in macrophages, thus promoting efflux of cholesterol; it also upregulates liver and intestinal ABCG5 and ABCG8, helping to promote biliary and fecal excretion of cholesterol. Thus, LXR agonism may inhibit atherosclerosis through promotion of reverse cholesterol transport (RCT) in vivo, but this has not been proven. We previously described an in vivo method to trace the movement of cholesterol from 3H-cholesterol-labeled J774 macrophages into plasma, into liver, and ultimately into the bile and feces as free cholesterol or bile acids. In the present study we used this approach to test the hypothesis that administration of the synthetic LXR agonist GW3965 would increase the rate of macrophage RCT in vivo. METHODS AND RESULTS: Three different mouse models-wild-type C57BL/6 mice, LDLR/apobec-1 double knockout mice, and human apolipoprotein (apo)B/cholesteryl ester transfer protein (CETP) double transgenic mice-were treated with either vehicle or GW3965. Mice were injected intraperitoneally with 3H-cholesterol-labeled and cholesterol-loaded macrophages and monitored for the appearance of 3H-tracer in plasma, liver, and feces. Administration of GW3965 significantly increased the levels of 3H-tracer in plasma and feces in all 3 mouse models. CONCLUSIONS: These results demonstrate that administration of the LXR agonist GW3965 increases the rate of RCT from macrophages to feces in vivo.