Cyclic adenosine monophosphate critically modulates cardiac GLP-1 receptor's anti-inflammatory effects.

BACKGROUND: Glucagon-like peptide (GLP)-1 receptor (GLP1R) agonists exert a multitude of beneficial cardiovascular effects beyond control of blood glucose levels and obesity reduction. They also have anti-inflammatory actions through both central and peripheral mechanisms. GLP1R is a G protein-coupled receptor (GPCR), coupling to adenylyl cyclase (AC)-stimulatory Gs proteins to raise cyclic 3`-5`-adenosine monophosphate (cAMP) levels in cells. cAMP exerts various anti-apoptotic and anti-inflammatory effects via its effectors protein kinase A (PKA) and Exchange protein directly activated by cAMP (Epac). However, the precise role and importance of cAMP in mediating GLP1R`s anti-inflammatory actions, at least in the heart, remains to be determined. To this end, we tested the effects of the GLP1R agonist liraglutide on lipopolysaccharide (LPS)-induced acute inflammatory injury in H9c2 cardiac cells, either in the absence of cAMP production (AC inhibition) or upon enhancement of cAMP levels via phosphodiesterase (PDE)-4 inhibition with roflumilast. METHODS & RESULTS: Liraglutide dose-dependently inhibited LPS-induced apoptosis and increased cAMP levels in H9c2 cells, with roflumilast but also PDE8 inhibition further enhancing cAMP production by liraglutide. GLP1R-stimulated cAMP markedly suppressed the LPS-dependent induction of pro-inflammatory tumor necrosis factor (TNF)-a, interleukin (IL)-1b, and IL-6 cytokine expression, of inducible nitric oxide synthase (iNOS) expression and nuclear factor (NF)-kB activity, of matrix metalloproteinases (MMP)-2 and MMP-9 levels and activities, and of myocardial injury markers in H9c2 cardiac cells. The effects of liraglutide were mediated by the GLP1R since they were abolished by the GLP1R antagonist exendin(9-39). Importantly, AC inhibition completely abrogated liraglutide`s suppression of LPS-dependent inflammatory injury, whereas roflumilast significantly enhanced the protective effects of liraglutide against LPS-induced inflammation. Finally, PKA inhibition or Epac1/2 inhibition alone only partially blocked liraglutide`s suppression of LPS-induced inflammation in H9c2 cardiac cells, but, together, PKA and Epac1/2 inhibition fully prevented liraglutide from reducing LPS-dependent inflammation. CONCLUSIONS: cAMP, via activation of both PKA and Epac, is essential for GLP1R`s anti-inflammatory signaling in cardiac cells and that cAMP levels crucially regulate the anti-inflammatory efficacy of GLP1R agonists in the heart. Strategies that elevate cardiac cAMP levels, such as PDE4 inhibition, may potentiate the cardiovascular, including anti-inflammatory, benefits of GLP1R agonist drugs.

Cyclic Adenosine Monophosphate in Cardiac and Sympathoadrenal GLP-1 Receptor Signaling: Focus on Anti-Inflammatory Effects.

Glucagon-like peptide-1 (GLP-1) is a multifunctional incretin hormone with various physiological effects beyond its well-characterized effect of stimulating glucose-dependent insulin secretion in the pancreas. An emerging role for GLP-1 and its receptor, GLP-1R, in brain neuroprotection and in the suppression of inflammation, has been documented in recent years. GLP-1R is a G protein-coupled receptor (GPCR) that couples to Gs proteins that stimulate the production of the second messenger cyclic 3',5'-adenosine monophosphate (cAMP). cAMP, acting through its two main effectors, protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac), exerts several anti-inflammatory (and some pro-inflammatory) effects in cells, depending on the cell type. The present review discusses the cAMP-dependent molecular signaling pathways elicited by the GLP-1R in cardiomyocytes, cardiac fibroblasts, central neurons, and even in adrenal chromaffin cells, with a particular focus on those that lead to anti-inflammatory effects by the GLP-1R. Fully elucidating the role cAMP plays in GLP-1R's anti-inflammatory properties can lead to new and more precise targets for drug development and/or provide the foundation for novel therapeutic combinations of the GLP-1R agonist medications currently on the market with other classes of drugs for additive anti-inflammatory effect.

Differential Modulation of Catecholamine and Adipokine Secretion by the Short Chain Fatty Acid Receptor FFAR3 and α2-Adrenergic Receptors in PC12 Cells.

Sympathetic nervous system (SNS) hyperactivity is mediated by elevated catecholamine (CA) secretion from the adrenal medulla, as well as enhanced norepinephrine (NE) release from peripheral sympathetic nerve terminals. Adrenal CA production from chromaffin cells is tightly regulated by sympatho-inhibitory α2-adrenergic (auto)receptors (ARs), which inhibit both epinephrine (Epi) and NE secretion via coupling to Gi/o proteins. α2-AR function is, in turn, regulated by G protein-coupled receptor (GPCR)-kinases (GRKs), especially GRK2, which phosphorylate and desensitize them, i.e., uncouple them from G proteins. On the other hand, the short-chain free fatty acid (SCFA) receptor (FFAR)-3, also known as GPR41, promotes NE release from sympathetic neurons via the Gi/o-derived free Gßγ-activated phospholipase C (PLC)-ß/Ca2+ signaling pathway. However, whether it exerts a similar effect in adrenal chromaffin cells is not known at present. In the present study, we examined the interplay of the sympatho-inhibitory α2A-AR and the sympatho-stimulatory FFAR3 in the regulation of CA secretion from rat adrenal chromaffin (pheochromocytoma) PC12 cells. We show that FFAR3 promotes CA secretion, similarly to what GRK2-dependent α2A-AR desensitization does. In addition, FFAR3 activation enhances the effect of the physiologic stimulus (acetylcholine) on CA secretion. Importantly, GRK2 blockade to restore α2A-AR function or the ketone body beta-hydroxybutyrate (BHB or 3-hydroxybutyrate), via FFAR3 antagonism, partially suppress CA production, when applied individually. When combined, however, CA secretion from PC12 cells is profoundly suppressed. Finally, propionate-activated FFAR3 induces leptin and adiponectin secretion from PC12 cells, two important adipokines known to be involved in tissue inflammation, and this effect of FFAR3 is fully blocked by the ketone BHB. In conclusion, SCFAs can promote CA and adipokine secretion from adrenal chromaffin cells via FFAR3 activation, but the metabolite/ketone body BHB can effectively inhibit this action.

Optimizing radiotherapy strategies for skull base chordoma: a comprehensive meta-analysis and systematic review of treatment modalities and outcomes.

OBJECTIVE: In the treatment of skull base chordoma (SBC) surgery is considered the mainstay approach, and gross-total resection has an established relationship with progression-free survival (PFS) and overall survival (OS). However, the tumor's location often interferes with attempts at complete resection. In this case, surgery for maximal resection followed by high-dose radiotherapy has been demonstrated to be the standard treatment. In this context, various modalities are available, yet no consensus exists on the most effective. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of different radiotherapy modalities for SBC. METHODS: Following PRISMA guidelines, the authors systematically searched for the treatment of SBC with radiation modalities in the PubMed, Cochrane, Web of Science, and EMBASE databases. Outcomes assessed for each modality were as follows: OS, PFS, local control (LC), and complications. The random-effects model was adopted. A single-proportion analysis with 95% CI was used to measure the effects in single-arm analysis. For the comparative analysis, the OR with 95% CI was used to compare outcome treatment effects. Heterogeneity was assessed using I2 statistics, and statistical significance was defined as p < 0.05. RESULTS: A total of 32 studies comprising 3663 patients, with 2322 patients who were treated with radiotherapeutic modalities, were included. Regarding 5-year OS findings in each modality study, the findings were as follows: in photon fractionated radiotherapy, an estimated rate of 77% (69%-84%, 568 patients); in conventional fractionated radiotherapy, 76% (65%-87%, 517 cases); in proton-based + carbon ion-based radiotherapy, 85% (82%-88%, 622 cases); and in a comparative analysis of proton-based and carbon ion-based therapy, there was an OR of 1.2 (95% CI 0.59-2.43, 306 cases). Regarding the 5-year PFS estimate, the rates were as follows: 35% (26%-45%, 95 cases) for photon fractionated therapy; 35% (25%-45%, 85 cases) for stereotactic radiotherapy; 77% (50%-100%, 180 cases) for proton-based and carbon ion-based radiotherapy; and 74% (45%-100%, 102 cases) for proton-based radiotherapy. Regarding LC in periods of 3 and 5 years after proton- and carbon ion-based therapy, the overall estimated rates were 84% (78%-90%, 326 cases) and 75% (65%-85%, 448 cases), respectively. For proton-based radiotherapy and carbon ion-based therapy, the 5-year LC rates were 76% (67%-86%, 259 cases) and 75% (59%-91%, 189 cases), respectively. CONCLUSIONS: The analysis highlights the finding that particle-based modalities like proton beam radiotherapy and carbon ion radiotherapy are the most effective radiation therapies available for the treatment of SBC. Furthermore, it reinforces the idea that surgery followed by radiotherapy constitutes the standard treatment.

Safety of local anesthesia in endovascular treatment of Aneurysms: A systematic review and Meta-Analysis.

BACKGROUND: Endovascular treatment of intracranial aneurysms (EVTIAs) is increasingly popular due to its minimally invasive nature and high success rate. While general anesthesia (GA) has been the historical preference for EVTIAs, there's growing interest in local anesthesia (LA). However, concerns persist about LA safety for EVTIAs. Therefore, we conducted a systematic review and meta-analysis to assess LA safety for EVTIAs. METHODS: Following PRISMA guidelines, we searched PubMed, Embase, and Web of Science databases. Pooled analysis with 95 % confidence intervals (CI) assessed effects, I2 statistics gauged heterogeneity, and a random-effects model was adopted. Conversion to GA, neurological or procedure-related complications, intraoperative intracranial hemorrhagic complications (IIHC), and mortality were assessed. Subanalyses for ruptured and unruptured cases were performed. RESULTS: The analysis included eleven studies, 2,133 patients, and 2,369 EVTIAs under LA. Conversion to GA rate was 1 % (95 %CI: 0 to 2 %). Neurological or procedure-related complications rate was 13 % (95 % CI: 8 % to 17 %). IIHC analysis revealed a rate of 1 % (95 % CI: 1 % to 2 %). The mortality rate was 0 % (95 %CI: 0 % to 0 %). Subanalyses revealed similar rates in ruptured and unruptured subgroups, except for a slightly high rate of complications and IIHC in the ruptured subgroup. CONCLUSION: Findings indicate that EVTIA under LA is safe, with low conversion and mortality rates, even for ruptured aneurysms. Complications rates, also in IIHC rates, are comparable to those reported for GA, emphasizing LA's comparable safety profile in EVTIAs. Considering these promising outcomes, the decision to opt for the LA approach emerges as meaningful and well-suited for the endovascular treatment of aneurysms. Beyond its safety, LA introduces inherent supplementary advantages, including shortened hospitalization periods, cost-effectiveness, and an expedited patient recovery process.

Nicotine Diminishes Alpha2-Adrenergic Receptor-Dependent Protection Against Oxidative Stress in H9c2 Cardiomyocytes.

Introduction: Nicotine is a major component of cigarette smoke with various detrimental cardiovascular effects, including increased oxidative stress in the heart. Agonism of α2-adrenergic receptors (ARs), such as with dexmedetomidine, has been documented to exert cardioprotective effects against oxidative stress and related apoptosis and necroptosis. α2-ARs are membrane-residing G protein-coupled receptors (GPCRs) that primarily activate Gi/o proteins. They are also subjected to GPCR-kinase (GRK)-2-dependent desensitization, which entails phosphorylation of the agonist-activated receptor by GRK2 to induce its decoupling from G proteins, thus terminating α2AR-mediated G protein signaling. Objective: In the present study, we sought to examine the effects of nicotine on α2AR signaling and effects in H9c2 cardiomyocytes exposed to H2O2 to induce oxidative cellular damage. Methods and Results: As expected, treatment of H9c2 cardiomyocytes with H2O2 significantly decreased cell viability and increased oxidative stress, as assessed by reactive oxygen species (ROS)-associated fluorescence levels (DCF assay) and superoxide dismutase activity. Both H2O2 effects were partly rescued by α2AR activation with brimonidine in control cardiomyocytes but not in cells pretreated with nicotine for 24 hours, in which brimonidine was unable to reduce H2O2-induced cell death and oxidative stress. This was due to severe α2AR desensitization, manifested as very low Gi protein activation by brimonidine, and accompanied by GRK2 upregulation in nicotine-treated cardiomyocytes. Finally, pharmacological inhibition of adenylyl cyclase (AC) blocked H2O2-dependent oxidative damage in nicotine-pretreated H9c2 cardiomyocytes, indicating that α2AR activation protects against oxidative injury via its classic coupling to Gai-mediated AC inhibition. Discussion/Conclusions: Nicotine can negate the cardioprotective effects of α2AR agonists against oxidative injury, which may have important implications for patients treated with this class of drugs that are chronic tobacco smokers.

Assessing the efficacy and safety of hemangioblastoma embolization: A comprehensive systematic review and meta-analysis.

BACKGROUND: Hemangioblastomas (HBs) are highly vascular tumors linked to substantial morbidity and mortality. Recently, interventional neuroradiology has evolved rapidly, spurring interest in preoperative embolization as a possible HB treatment. PURPOSE: This study evaluates the effectiveness and safety of preoperative embolization in managing HB. METHODS: Adhering to PRISMA guidelines, this meta-analysis considered randomized and nonrandomized studies meeting specific criteria, encompassing intracranial HB and preoperative embolization. Primary outcomes were preoperative embolization efficacy and safety. Complications were classified as major (cerebellar ischemia, ischemic strokes, intratumoral hemorrhage, subarachnoid hemorrhage) and minor (transient nystagmus, slight facial nerve palsy, nausea, transient dysarthria, hemiparesis, hemisensory impairment, thrombotic complications, extravasation). RESULTS: Thirteen studies involving 166 patients with preoperative embolization before HB resection were included. Two studies using the Glasgow Outcome Scale (GOS) showed 5 patients with good recovery, 6 with moderate disability, and 3 with severe disability. Major complications occurred in 1% (95% CI: 0% to 3%), and minor complications occurred in 1% (95% CI: 0% to 4%). Intraoperative blood loss during resection was estimated at 464.29 ml (95% CI: 350.63 ml to 614.80 ml). CONCLUSION: Preoperative embolization holds promise in reducing intraoperative bleeding risk in neurosurgical intracranial HB treatment, primarily due to its low complication rates. Nonetheless, additional research and larger-scale studies are essential to establish its long-term efficacy and safety. These findings highlight preoperative embolization as a valuable tool for HB management, potentially enhancing future patient outcomes.

Serological levels of IGF-1 and IGFBP-3 in patients with Barrett's esophagus and esophageal adenocarcinoma: Longitudinal study. / Niveles séricos de IGF-1 e IGFBP-3 en pacientes con esófago de Barrett y adenocarcinoma de esófago. Estudio longitudinal.

BACKGROUND: Barrett's esophagus (BE) is an entity with a known histological progression to malignancy. The insulin-like growth factor (IGF) system is involved in the carcinogenesis through obesity-related mechanisms that include IGF and it has been associated with several types of cancer. OBJECTIVES: To evaluate the serological levels of IGF-1 and IGFBP-3 in patients with BE and esophageal adenocarcinoma. PATIENTS AND METHODS: Prospective study of patients with BE and esophageal adenocarcinoma who underwent upper endoscopy between September 2012 and December 2015. A baseline determination of IGF-1 and IGFBP-3 was performed. We included a control group of patients without BE. RESULTS: One hundred sixteen patients were included: 36 controls, 62 with BE (42 without dysplasia and 20 with dysplasia) and 18 with adenocarcinoma. IGF-1 and IGF-1/IGFBP-3 molar ratio showed a progression to high levels in BE and adenocarcinoma than in controls (IGF-1: 135.55±66.07ng/ml, 148.33±81.5ng/ml, 108.19±46.69ng/ml, respectively; P=.049) (molar ratio: 0.23±0.91, 0.29±0.11, 0.19±0.06, respectively; P=.001), without differences between the histological types of BE. Fifty-four out of the 65 patients with BE were followed up (median of 58.50 months, range 12-113) and 11 of them (20.4%) presented progression to low-grade dysplasia (n=8) or high-grade dysplasia/adenocarcinoma (n=3), without differences in the IGF system compared with patients without progression. CONCLUSIONS: Patients with BE and esophageal adenocarcinoma have changes in the IGF system although the serological levels of IGF-1 and IGFBP-3 do not correlate with histological progression of BE.

Impact of Aldosterone on the Failing Myocardium: Insights from Mitochondria and Adrenergic Receptors Signaling and Function.

The mineralocorticoid aldosterone regulates electrolyte and blood volume homeostasis, but it also adversely modulates the structure and function of the chronically failing heart, through its elevated production in chronic human post-myocardial infarction (MI) heart failure (HF). By activating the mineralocorticoid receptor (MR), a ligand-regulated transcription factor, aldosterone promotes inflammation and fibrosis of the heart, while increasing oxidative stress, ultimately induding mitochondrial dysfunction in the failing myocardium. To reduce morbidity and mortality in advanced stage HF, MR antagonist drugs, such as spironolactone and eplerenone, are used. In addition to the MR, aldosterone can bind and stimulate other receptors, such as the plasma membrane-residing G protein-coupled estrogen receptor (GPER), further complicating it signaling properties in the myocardium. Given the salient role that adrenergic receptor (ARs)-particularly ßARs-play in cardiac physiology and pathology, unsurprisingly, that part of the impact of aldosterone on the failing heart is mediated by its effects on the signaling and function of these receptors. Aldosterone can significantly precipitate the well-documented derangement of cardiac AR signaling and impairment of AR function, critically underlying chronic human HF. One of the main consequences of HF in mammalian models at the cellular level is the presence of mitochondrial dysfunction. As such, preventing mitochondrial dysfunction could be a valid pharmacological target in this condition. This review summarizes the current experimental evidence for this aldosterone/AR crosstalk in both the healthy and failing heart, and the impact of mitochondrial dysfunction in HF. Recent findings from signaling studies focusing on MR and AR crosstalk via non-conventional signaling of molecules that normally terminate the signaling of ARs in the heart, i.e., the G protein-coupled receptor-kinases (GRKs), are also highlighted.