Postoperative bioactive adrenomedullin is associated with the onset of ARDS and adverse outcomes in patients undergoing open thoracoabdominal aortic surgery.

Cytokine-mediated systemic inflammation after open thoracoabdominal aortic aneurysm (TAAA) repairs plays a pivotal role in disrupting circulatory homeostasis, potentially leading to organ dysfunction. The bioactive form of adrenomedullin (bio-ADM) is a peptide hormone with immunomodulatory and vasomotor effects, making it a potential diagnostic agent in these cases. This retrospective, bicentric study, conducted between January 2019 and December 2022, recruited 36 elective open TAAA repair patients in two German centres. Serum and plasma samples were collected at multiple time points to measure bio-ADM levels. The primary objective was to evaluate the association of bio-ADM levels with the onset of acute respiratory distress syndrome (ARDS), with secondary endpoints focusing on mortality and SIRS-related morbidity. Results showed a significant association between postoperative bio-ADM levels (12-48 h after surgery) and the onset of ARDS (p < .001), prolonged ventilation (p = .015 at 12h after surgery), atrial fibrillation (p < .001), and mortality (p = .05 at 24h). The biomarker was also strongly associated with sepsis (p = .01 at 12 h) and multi-organ dysfunction syndrome (MODS) (p = .02 at 24 h after surgery). The study underscores the potential utility of bio-ADM as a diagnostic tool for identifying patients at risk of postoperative complications following open TAAA repairs.

Identification of hypoxic macrophages in glioblastoma with therapeutic potential for vasculature normalization.

Monocyte-derived tumor-associated macrophages (Mo-TAMs) intensively infiltrate diffuse gliomas with remarkable heterogeneity. Using single-cell transcriptomics, we chart a spatially resolved transcriptional landscape of Mo-TAMs across 51 patients with isocitrate dehydrogenase (IDH)-wild-type glioblastomas or IDH-mutant gliomas. We characterize a Mo-TAM subset that is localized to the peri-necrotic niche and skewed by hypoxic niche cues to acquire a hypoxia response signature. Hypoxia-TAM destabilizes endothelial adherens junctions by activating adrenomedullin paracrine signaling, thereby stimulating a hyperpermeable neovasculature that hampers drug delivery in glioblastoma xenografts. Accordingly, genetic ablation or pharmacological blockade of adrenomedullin produced by Hypoxia-TAM restores vascular integrity, improves intratumoral concentration of the anti-tumor agent dabrafenib, and achieves combinatorial therapeutic benefits. Increased proportion of Hypoxia-TAM or adrenomedullin expression is predictive of tumor vessel hyperpermeability and a worse prognosis of glioblastoma. Our findings highlight Mo-TAM diversity and spatial niche-steered Mo-TAM reprogramming in diffuse gliomas and indicate potential therapeutics targeting Hypoxia-TAM to normalize tumor vasculature.

Bioactive adrenomedullin as a marker of congestion and disease progression in patients with a systemic right ventricle.

BACKGROUND: Adults with a systemic right ventricle (sRV) are at a high risk for heart failure (HF) hospitalization and mortality. Bioactive adrenomedullin (bio-ADM) has been proposed as a marker of congestion and prognosis in patients with cardiovascular disease. We aimed to evaluate the association between bio-ADM and mortality and HF events in sRV patients. METHODS: Plasma bio-ADM was measured by a novel immunoassay in plasma of 85 sRV patients. A composite endpoint of all-cause mortality and HF events was used as outcome. HF events were defined as onset or progression of HF signs or symptoms requiring hospitalization, initiation or intensification of therapy. Multivariable Cox regression analyses were performed to evaluate the association between bio-ADM and outcome. RESULTS: The mean age of the patients was 37 ± 9 years and 65% were male. Patients with higher plasma bio-ADM concentrations were more often treated with diuretics (p = 0.007), possibly because of signs and/or symptoms of congestion. During a median follow-up of 10.2 years, 33.7% of the patients reached the endpoint. After adjustment for age and N-terminal pro B-type natriuretic peptide (NT-pro BNP), higher bio-ADM levels were associated with a higher risk of the composite endpoint (hazard ratio: 2.09 [95%-confidence interval: 1.15-3.78]). Bio-ADM improved risk prediction when added to NT-proBNP and age (C-statistic improved from 0.748 to 0.776 [p = 0.03]). CONCLUSIONS: Bio-ADM can be considered as a marker of congestion and independent predictor of death and HF events in adult patients with a sRV. Moreover, in terms of risk prediction, it has added value to NT-proBNP.

Variable CGRP family peptide signaling durations and the structural determinants thereof.

Calcitonin gene-related peptides alpha and beta (αCGRP, ßCGRP), adrenomedullin (AM), and adrenomedullin 2/intermedin (AM2/IMD) function in pain signaling, neuroimmune communication, and regulation of the cardiovascular and lymphatic systems by activating either of two class B GPCRs, CLR and CTR, in complex with a RAMP1, -2, or -3 modulatory subunit. Inspired by our recent discovery that AM2/IMD(1-47) activation of CLR-RAMP3 elicits long duration cAMP signaling, here we used a live-cell cAMP biosensor assay to characterize the signaling kinetics of the two CGRP peptides and several bioactive AM and AM2/IMD fragments with variable N-terminal extensions. Remarkably, AM2/IMD(8-47) and AM2/IMD-53 exhibited even longer duration signaling than the 1-47 fragment. AM2/IMD(8-47) was a striking 8-fold longer acting than AM(13-52) at CLR-RAMP3. In contrast, the N-terminal extension of AM had no effect on signaling duration. AM(1-52) and (13-52) were equally short-acting. Analysis of AM2/IMD-AM mid-region chimeras and AM2/IMD R23 and R33 point mutants showed the importance of these residues for long-duration signaling and identified AM2/IMD peptides that exhibited up to 17-fold diminished signaling duration at CLR-RAMP3, while retaining near wildtype signaling potencies. ßCGRP was âˆ¼ 3-fold longer acting than αCGRP at the CGRP (CLR-RAMP1) and the amylin1 (CTR-RAMP1) receptors. Chimeric CGRP peptides showed that the single residue difference near the N-terminus, and the two differences in the mid-region, equally contributed to the longer duration of ßCGRP signaling. This work uncovers key temporal differences in cAMP signaling among the CGRP family peptides, elucidates the structural bases thereof, and provides pharmacological tools for studying long-duration AM2/IMD signaling.

Mineralised collagen regulated the secretion of adrenomedullin by macrophages to activate the PI3K/AKT signalling pathway to promote bone defect repair.

Biomaterials can affect the osteogenic process by regulating the function of macrophages and transforming the bone immune microenvironment. Mineralised collagen (MC) is an artificial bone that is highly consistent to the microstructure of the native osseous matrix. The studies have confirmed that MC can achieve effective regeneration of bone defects, but the potential mechanism of MC regulating osteogenesis is still unclear. This study confirmed that MC regulate the high expression of adrenomedullin (ADM) in macrophages and promote the osteogenic differentiation, proliferation and migration of BMSCs. Moreover, ADM activated the PI3K/Akt pathway, while the inhibition of PI3K/Akt hindered the proliferation, migration and osteogenic differentiation of BMSCs promoted by ADM. Additionally, the rat mandibular defect model confirmed that ADM promote the repair of mandibular defects, and the inhibition of PI3K/Akt pathway hinders the osteogenic effect of ADM. Our study suggests that MC regulates ADM secretion by macrophages, creates an ideal bone immune microenvironment, activates the PI3K/AKT signalling pathway, and promotes osteogenesis.

Biomarkers Improve Diagnostics of Sepsis in Adult Patients With Suspected Organ Dysfunction Based on the Quick Sepsis-Related Organ Failure Assessment (qSOFA) Score in the Emergency Department.

OBJECTIVES: Consensus regarding biomarkers for detection of infection-related organ dysfunction in the emergency department is lacking. We aimed to identify and validate biomarkers that could improve risk prediction for overt or incipient organ dysfunction when added to quick Sepsis-related Organ Failure Assessment (qSOFA) as a screening tool. DESIGN: In a large prospective multicenter cohort of adult patients presenting to the emergency department with a qSOFA score greater than or equal to 1, admission plasma levels of C-reactive protein, procalcitonin, adrenomedullin (either bioavailable adrenomedullin or midregional fragment of proadrenomedullin), proenkephalin, and dipeptidyl peptidase 3 were assessed. Least absolute shrinkage and selection operator regression was applied to assess the impact of these biomarkers alone or in combination to detect the primary endpoint of prediction of sepsis within 96 hours of admission. SETTING: Three tertiary emergency departments at German University Hospitals (Jena University Hospital and two sites of the Charité University Hospital, Berlin). PATIENTS: One thousand four hundred seventy-seven adult patients presenting with suspected organ dysfunction based on qSOFA score greater than or equal to 1. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cohort was of moderate severity with 81% presenting with qSOFA = 1; 29.2% of these patients developed sepsis. Procalcitonin outperformed all other biomarkers regarding the primary endpoint (area under the curve for receiver operating characteristic [AUC-ROC], 0.86 [0.79-0.93]). Adding other biomarkers failed to further improve the AUC-ROC for the primary endpoint; however, they improved the model regarding several secondary endpoints, such as mortality, need for vasopressors, or dialysis. Addition of procalcitonin with a cutoff level of 0.25 ng/mL improved net (re)classification by 35.2% compared with qSOFA alone, with positive and negative predictive values of 60.7% and 88.7%, respectively. CONCLUSIONS: Biomarkers of infection and organ dysfunction, most notably procalcitonin, substantially improve early prediction of sepsis with added value to qSOFA alone as a simple screening tool on emergency department admission.

Bioactive adrenomedullin and interleukin-6 in COVID-19: potential biomarkers of acute kidney injury and critical illness.

BACKGROUND: The aim of this study was to investigate whether bioactive adrenomedullin (bio-ADM) and interleukin-6 (IL-6) are related to acute kidney injury (AKI) and severe illness in COVID-19 patients. METHODS: 153 patients with COVID-19 admitted to the emergency department (ED) were included. Blood samples were collected from each patient at admission. Bio-ADM and IL-6, as well as DPP3 and routinely measured markers were evaluated regarding the endpoints AKI (22/128 hospitalized patients) and a composite endpoint of admission to intensive care unit and/or in-hospital death (n = 26/153 patients). RESULTS: Bio-ADM and IL-6 were significantly elevated in COVID-19 patients with AKI compared to COVID-19 patients without AKI (each p < 0.001). According to ROC analyses IL-6 and bio-ADM had the largest AUC (0.84 and 0.81) regarding the detection of AKI. Furthermore, bio-ADM and IL-6 were significantly elevated in COVID-19 patients reaching the composite endpoint (each p < 0.001). Regarding the composite endpoint ROC analysis showed an AUC of 0.89 for IL-6 and 0.83 for bio-ADM in COVID-19 patients. In the multivariable logistic model bio-ADM and IL-6 presented as independent significant predictors regarding both endpoints AKI and the composite endpoint in COVID-19 patients (as well as creatinine regarding the composite endpoint; each p < 0.05), opposite to leukocytes, C-reactive protein (CRP) and dipeptidyl peptidase 3 (DPP3; each p = n.s.). CONCLUSION: Elevated levels of bio-ADM and IL-6 are associated with AKI and critical illness in patients with COVID-19. Therefore, both biomarkers may be potential tools in risk stratification in COVID-19 patients at presentation in the ED.

New insight into prurigo nodularis: Proadrenomedullin N-terminal 20 peptide mediates mouse mast cell activation via Mrgprb2.

BACKGROUND: Prurigo nodularis (PN) is a chronic inflammatory skin disorder that is characterized by extremely itchy nodules. Proadrenomedullin N-terminal 20 (PAMP) activates mast cell degranulation via Mas-related G protein-coupled receptor X2 (MRGPRX2), which is associated with pruritus in allergic contact dermatitis. However, the mechanisms underlying the action of PAMP and MRGPRX2 in PN remain unclear. OBJECTIVE: To determine the role of PAMP-induced mast cell activation via MRGPRX2 (mouse homologous Mrgprb2) in PN. METHODS: The expression of PAMP and the number of MRGPRX2-expressing mast cells in the skin biopsies of patients with PN, atopic dermatitis (AD), and healthy participants were analyzed using immunohistochemistry and immunofluorescence, respectively. The biphasic response of PAMP9-20 mediated by Mrgprb2 in mouse peritoneal mast cells (PMC) was validated in vitro using qRT-PCR, ELISA, flow cytometry, and siRNA techniques. RESULTS: PAMP expression and the number of MRGPRX2+ mast cells in lesional PN skin, but not in AD, were elevated compared to healthy skin. PAMP9-20 mediates the immediate and delayed phase responses of PMC, such as degranulation, histamine and ß-hexosaminidase release, and secretion of inflammatory factors such as CCL2, TNF-α, and GM-CSF. These effects were inhibited when Mrgprb2 expression was silenced. Silencing Mrgprb2 did not affect the biphasic response of PMC that was induced by IgE-FcεRI activation. CONCLUSIONS: The results show that PAMP mediates mouse mast cell activation via Mrgprb2, which may be involved in the pathogenesis of PN. The PAMP/ Mrgprb2 pathway, independent of classical IgE signaling, could be developed as a candidate drug target for treating PN.

Adrenomedullin, transcriptionally regulated by vitamin D receptors, alleviates atherosclerosis in mice through suppressing AMPK-mediated endothelial ferroptosis.

PURPOSE: Vitamin D receptors (VDR) play important roles in cardiovascular, immune, metabolic and other functions. Activation of VDR may help improve endothelial dysfunction, atherosclerosis, vascular calcification, and cardiac hypertrophy. However, the specific target genes and mechanisms of VDR in improving Human Umbilical Vein Endothelial Cell (HUVEC) functions remain unclear. This study aims to investigate the function and mechanism of VDR in HUVECs. METHODS: Endothelial dysfunction cell model was constructed by oxidized low-density lipoprotein (ox-LDL). An animal model of atherosclerosis was established in male homozygous Apoe-/- mice (6 weeks) on a high fat diet for 6 weeks. The relationship between VDR and adrenomedullin (ADM) was studied by bioinformatics analysis, ChIP, and luciferase reporter gene analysis. Endothelial cell function was evaluated by Transwell migration and Tube Formation tests. Ferroptosis was detected by measuring intracellular iron content, levels of oxidative stress markers, and ferroptosis related proteins. RESULTS: Overexpression of VDR in HUVECs inhibits ox-LDL-induced endothelial dysfunction and ferroptosis. VDR binds to the ADM promoter sequence and regulates the transcription of ADM. Inhibition of ADM promotes ox-LDL-induced endothelial dysfunction and ferroptosis. ADM regulates ox-LDL-induced endothelial dysfunction and ferroptosis through the AMPK signaling pathway. Overexpression of VDR in Apoe-/- mice inhibited lipid deposition and plaque area in atherosclerotic mice. CONCLUSION: VDR inhibits ox-LDL-induced endothelial dysfunction and ferroptosis by regulating ADM transcription and acting on AMPK signaling pathway. Overexpression of VDR in Apoe-/- mice reduced lipid deposition and plaque area in the thoracic aorta of atherosclerotic mice.

Bioactive adrenomedullin (bio-ADM) is associated with endothelial dysfunction in infants and children with complex congenital heart disease undergoing open-heart surgery on cardiopulmonary bypass.

OBJECTIVES: Children with congenital heart disease (CHD) undergoing cardiac surgery on cardiopulmonary bypass (CPB) are at risk for systemic inflammation leading to endothelial dysfunction associated with increased morbidity. Bioactive adrenomedullin (bio-ADM) is a peptide regulating vascular tone and endothelial permeability. The aim of this study was to evaluate the dynamics of plasma bio-ADM in this patient cohort and its role in capillary leak. METHODS: Plasma samples from 73 pediatric CHD patients were collected for bio-ADM measurement at five different timepoints (TP) in the pre-, intra-, and post-operative period. The primary endpoint was a net increase in bio-ADM levels after surgery on CPB. Secondary endpoints included association of bio-ADM levels with clinical signs for endothelial dysfunction. RESULTS: Bio-ADM levels increased after surgery on CPB from pre-operative median of 12 pg/mL (IQR [interquartile range] 12.0-14.8 pg/mL) to a maximum post-operative median of 48.8 pg/mL (IQR 34.5-69.6 pg/mL, p<0.001). Bio-ADM concentrations correlated positively with post-operative volume balance, (r=0.341; p=0.005), increased demand for vasoactive medication (duration: r=0.415; p<0.001; quantity: TP3: r=0.415, p<0.001; TP4: r=0.414, p<0.001), and hydrocortisone treatment for vasoplegia (bio-ADM median [IQR]:129.1 [55.4-139.2] pg/mL vs. 37.9 [25.2-64.6] pg/mL; p=0.034). Patients who required pleural effusion drainage revealed higher bio-ADM levels compared to those who did not (median [IQR]: 66.4 [55.4-90.9] pg/mL vs. 40.2 [28.2-57.0] pg/mL; p<0.001). CONCLUSIONS: Bio-ADM is elevated in children after cardiac surgery and higher levels correlate with clinical signs of capillary leakage. The peptide should be considered as biomarker for endothelial dysfunction and as potential therapeutic target in this indication.

Receptor activity-modifying proteins of adrenomedullin (RAMP2/3): Roles in the pathogenesis of ARDS.

Acute respiratory distress syndrome (ARDS) is a life-threatening lung condition characterized by widespread inflammation and pulmonary edema. Adrenomedullin (AM), a bioactive peptide with various functions, is expected to be applied in treating ARDS. Its functions are regulated primarily by two receptor activity-modifying proteins, RAMP2 and RAMP3, which bind to the AM receptor calcitonin receptor-like receptor (CLR). However, the roles of RAMP2 and RAMP3 in ARDS remain unclear. We generated a mouse model of ARDS via intratracheal administration of lipopolysaccharide (LPS), and analyzed the pathophysiological significance of RAMP2 and RAMP3. RAMP2 expression declined with LPS administration, whereas RAMP3 expression increased at low doses and decreased at high doses of LPS. After LPS administration, drug-inducible vascular endothelial cell-specific RAMP2 knockout mice (DI-E-RAMP2-/-) showed reduced survival, increased lung weight, and had more apoptotic cells in the lungs. DI-E-RAMP2-/- mice exhibited reduced expression of Epac1 (which regulates vascular endothelial cell barrier function), while RAMP3 was upregulated in compensation. In contrast, after LPS administration, RAMP3-/- mice showed no significant changes in survival, lung weight, or lung pathology, although they exhibited significant downregulation of iNOS, TNF-α, and NLRP3 during the later stages of inflammation. Based on transcriptomic analysis, RAMP2 contributed more to the circulation-regulating effects of AM, whereas RAMP3 contributed more to its inflammation-regulating effects. These findings indicate that, while both RAMP2 and RAMP3 participate in ARDS pathogenesis, their functions differ distinctly. Further elucidation of the pathophysiological significance and functional differences between RAMP2 and RAMP3 is critical for the future therapeutic application of AM in ARDS.

Mid-Regional Proadrenomedullin in COVID-19-May It Act as a Predictor of Prolonged Cardiovascular Complications?

The rising prevalence of cardiovascular disease (CVD) and the impact of the SARS-CoV-2 pandemic have both led to increased mortality rates, affecting public health and the global economy. Therefore, it is essential to find accessible, non-invasive prognostic markers capable of identifying patients at high risk. One encouraging avenue of exploration is the potential of mid-regional proadrenomedullin (MR-proADM) as a biomarker in various health conditions, especially in the context of CVD and COVID-19. MR-proADM presents the ability to predict mortality, heart failure, and adverse outcomes in CVD, offering promise for improved risk assessment and treatment strategies. On the other hand, an elevated MR-proADM level is associated with disease severity and cytokine storms in patients with COVID-19, making it a predictive indicator for intensive care unit admissions and mortality rates. Moreover, MR-proADM may have relevance in long COVID, aiding in the risk assessment, triage, and monitoring of individuals at increased risk of developing prolonged cardiac issues. Our review explores the potential of MR-proADM as a predictor of enduring cardiovascular complications following COVID-19 infection.

Mid-Regional Pro-Adrenomedullin Can Predict Organ Failure and Prognosis in Sepsis?

Sepsis causes immune dysregulation and endotheliitis, with an increase in mid-regional pro-adrenomedullin (MR-proADM). The aim of the study is to determine an MR-proADM value that, in addition to clinical diagnosis, can identify patients with localized infection or those with sepsis/septic shock, with specific organ damage or with the need for intensive care unit (ICU) transfer and prognosis. The secondary aim is to correlate the MR-proADM value with the length of stay (LOS). In total, 301 subjects with sepsis (124/301 with septic shock) and 126 with localized infection were retrospectively included. In sepsis, MR-proADM ≥ 3.39 ng/mL identified acute kidney injury (AKI); ≥2.99 ng/mL acute respiratory distress syndrome (ARDS); ≥2.28 ng/mL acute heart failure (AHF); ≥2.55 ng/mL Glascow Coma Scale (GCS) < 15; ≥3.38 multi-organ involvement; ≥3.33 need for ICU transfer; ≥2.0 Sequential Organ Failure Assessment (SOFA) score ≥ 2; and ≥3.15 ng/mL non-survivors. The multivariate analysis showed that MR-proADM ≥ 2 ng/mL correlates with AKI, anemia and SOFA score ≥ 2, and MR-proADM ≥ 3 ng/mL correlates with AKI, GCS < 15 and SOFA score ≥ 2. A correlation between mortality and AKI, GCS < 15, ICU transfer and cathecolamine administration was found. In localized infection, MR-proADM at admission ≥ 1.44 ng/mL identified patients with AKI; ≥1.0 ng/mL with AHF; and ≥1.44 ng/mL with anemia and SOFA score ≥ 2. In the multivariate analysis, MR-proADM ≥ 1.44 ng/mL correlated with AKI, anemia, SOFA score ≥ 2 and AHF. MR-proADM is a marker of oxidative stress due to an infection, reflecting severity proportionally to organ damage.

Adrenomedullin has a pivotal role in trophoblast differentiation: A promising nanotechnology-based therapeutic target for early-onset preeclampsia.

Early-onset preeclampsia (EOPE) is a severe pregnancy complication associated with defective trophoblast differentiation and functions at implantation, but manifestation of its phenotypes is in late pregnancy. There is no reliable method for early prediction and treatment of EOPE. Adrenomedullin (ADM) is an abundant placental peptide in early pregnancy. Integrated single-cell sequencing and spatial transcriptomics confirm a high ADM expression in the human villous cytotrophoblast and syncytiotrophoblast. The levels of ADM in chorionic villi and serum were lower in first-trimester pregnant women who later developed EOPE than those with normotensive pregnancy. ADM stimulates differentiation of trophoblast stem cells and trophoblast organoids in vitro. In pregnant mice, placenta-specific ADM suppression led to EOPE-like phenotypes. The EOPE-like phenotypes in a mouse PE model were reduced by a placenta-specific nanoparticle-based forced expression of ADM. Our study reveals the roles of trophoblastic ADM in placental development, EOPE pathogenesis, and its potential clinical uses.

Peptidylglycine α-amidating monooxygenase and adrenomedullin measurement in patients with hepatic cirrhosis.

Background: Peptidylglycine α-amidating monooxygenase (PAM) is an enzyme involved in the maturation of regulatory peptides. Here we examined PAM activity and adrenomedullin (bio-ADM) concentrations in patients with hepatic cirrhosis and determined net changes across the liver, kidneys and leg. Materials & methods: A total of 48 patients with hepatic cirrhosis and 16 control subjects were included. All patients and controls underwent an invasive procedure with blood collected across organs. Results: PAM activity was increased in cirrhotic patients but without a net change across the liver, leg or kidney. In contrast, bio-ADM concentrations were associated with severity of disease and found to be higher in venous blood from the liver. Conclusion: Increased PAM activity in patients with hepatic cirrhosis may reflect other organs involved in cirrhotic disease.

Severe liver disease is a life-threatening condition that affects people all over the world. To improve doctors' ability to diagnose the disease and to follow the disease as it progresses, there is a need for new tools. Biomarkers are often used as such tools for measuring the presence and severity of a disease. In this study, we examined two potential biomarkers in blood from patients with severe liver disease: peptidylglycine α-amidating monooxygenase (PAM) activity and bioactive adrenomedullin (bio-ADM). We examined whether these biomarkers are present in blood and in amounts associated with disease severity. We also tested if the diseased liver releases the biomarkers. We found that bio-ADM is increased in blood from patients with severe liver disease and that the liver itself releases bio-ADM to the bloodstream. For PAM activity, we also detected increased activity in blood associated with disease severity. In contrast, however, this biomarker was not shown to be released by the liver. Taken together, the two biomarkers may help to improve severe liver disease diagnosis and maybe allow for biochemical follow-up as the disease progresses.

Intermedin alleviates diabetic vascular calcification by inhibiting GLUT1 through activation of the cAMP/PKA signaling pathway.

BACKGROUND AND AIMS: Vascular calcification (VC) is regarded as an independent risk factor for cardiovascular events in type 2 diabetic patients. Glucose transporter 1 (GLUT1) involves VC. Intermedin/Adrenomedullin-2 (IMD/ADM2) is a cardiovascular protective peptide that can inhibit multiple disease-associated VC. However, the role and mechanism of IMD in diabetic VC remain unclear. Here, we investigated whether IMD inhibits diabetic VC by inhibiting GLUT1. METHODS AND RESULTS: It was found that plasma IMD concentration was significantly decreased in type 2 diabetic patients and in fructose-induced diabetic rats compared with that in controls. Plasma IMD content was inversely correlated with fasting blood glucose level and VC severity. IMD alleviated VC in fructose-induced diabetic rats. Deficiency of Adm2 aggravated and Adm2 overexpression attenuated VC in high-fat diet-induced diabetic mice. In vitro, IMD mitigated high glucose-induced calcification of vascular smooth muscle cells (VSMCs). Mechanistically, IMD reduced advanced glycation end products (AGEs) content and the level of receptor for AGEs (RAGE). IMD decreased glucose transporter 1 (GLUT1) levels. The inhibitory effect of IMD on RAGE protein level was blocked by GLUT1 knockdown. GLUT1 knockdown abolished the effect of IMD on alleviating VSMC calcification. IMD receptor antagonist IMD17-47 and cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) inhibitor H89 abolished the inhibitory effects of IMD on GLUT1 and VSMC calcification. CONCLUSIONS: These findings revealed that IMD exerted its anti-calcification effect by inhibiting GLUT1, providing a novel therapeutic target for diabetic VC.

Adrenomedullin has no effect on segmental bone defect healing but increases bone mineral density in rat model.

OBJECTIVE: This study aimed to investigate the effect of adrenomedullin on the healing of the segmental bone defect in a rat model. METHODS: Thirty-six Wistar rats were randomly divided into 6 groups based on follow-up periods and administered a dose of adrenomedullin hormone. In each group, bilaterally, a 2-mm bone defect was created at the diaphysis of the radius. Sodium chloride solution was administered to sham groups 3 times a week for 4 and 8 weeks intraperitoneally. Adrenomedullin was administered to the study groups 3 times a week: 15 µg-4 weeks, 15 µg-8 weeks, 30 µg-4 weeks, and 30 µg-8 weeks, respectively. After euthanasia, the segmental defects were evaluated by histomorphometric [new bone area (NBA)] and microtomographic [bone volume (BV), bone surface (BS), and bone mineral density (BMD)] analyses. RESULTS: Although the 4- and 8-week 15 µg administered study groups had higher NBA values than the other study and control groups, the histomorphometric analysis did not reveal any statistical difference between the control and study groups regarding NBA (P > .05). In microtomographic analysis, BV was higher in the 15 µg 4-week group than 30 µg 4-week group (296.9 vs. 208.5, P=.003), and BS was lower in the 30 µg 4-week group than in the 4-week control group (695.5 vs. 1334.7, P=.005), but overall, no significant difference was found between the control and study groups (P > .05). Despite these minor differences in histomorphometric and microtomographic criteria indicating new bone formation, the BMD values of the 15 µg 8-week study group showed a significant increase compared with the control group (P=.001, respectively). CONCLUSION: Adrenomedullin positively affected BMD at 15 µg, but this study could not show healing in the segmental defect site at different dose regimens. Further studies are needed to assess its effects on bone tissue trauma.

Adrenomedullin/FOXO3 enhances sunitinib resistance in clear cell renal cell carcinoma by inhibiting FDX1 expression and cuproptosis.

Cuproptosis, a new type of copper-induced cell death, is involved in the antitumor activity and resistance of multiple chemotherapeutic drugs. Our previous study revealed that adrenomedullin (ADM) was engaged in sunitinib resistance in clear cell renal cell carcinoma (ccRCC). However, it has yet to be investigated whether and how ADM regulates sunitinib resistance by cuproptosis. This study found that the ADM expression was elevated in sunitinib-resistant ccRCC tissues and cells. Furthermore, the upregulation of ADM significantly enhanced the chemoresistance of sunitinib compared with their respective control. Moreover, cuproptosis was involved in ADM-regulated sunitinib resistance by inhibiting mammalian ferredoxin 1 (FDX1) expression. Mechanically, the upregulated ADM activates the p38/MAPK signaling pathway to promote Forkhead box O3 (FOXO3) phosphorylation and its entry into the nucleus. Consequently, the increased FOXO3 in the nucleus inhibited FDX1 transcription and cell cuproptosis, promoting chemoresistance. Collectively, cuproptosis has a critical effector role in ccRCC progress and chemoresistance and thus is a relevant target to eradicate the cell population of sunitinib resistance.

Protein Biomarkers of Early Menopause and Incident Cardiovascular Disease.

Background Premature and early menopause are independently associated with greater risk of cardiovascular disease (CVD). However, mechanisms linking age of menopause with CVD remain poorly characterized. Methods and Results We measured 71 circulating CVD protein biomarkers in 1565 postmenopausal women enrolled in the FHS (Framingham Heart Study). We examined the association of early menopause with biomarkers and tested whether early menopause modified the association of biomarkers with incident cardiovascular outcomes (heart failure, major CVD, and all-cause death) using multivariable-adjusted linear regression and Cox models, respectively. Among 1565 postmenopausal women included (mean age 62 years), 395 (25%) had a history of early menopause. Of 71 biomarkers examined, we identified 7 biomarkers that were significantly associated with early menopause, of which 5 were higher in women with early menopause including adrenomedullin and resistin, and 2 were higher in women without early menopause including insulin growth factor-1 and CNTN1 (contactin-1) (Benjamini-Hochberg adjusted P<0.1 for all). Early menopause also modified the association of specific biomarkers with incident cardiovascular outcomes including adrenomedullin (Pint<0.05). Conclusions Early menopause is associated with circulating levels of CVD protein biomarkers and appears to modify the association between select biomarkers with incident cardiovascular outcomes. Identified biomarkers reflect several distinct biological pathways, including inflammation, adiposity, and neurohormonal regulation. Further investigation of these pathways may provide mechanistic insights into the pathogenesis, prevention, and treatment of early menopause-associated CVD.

Changes in mid-regional pro-adrenomedullin during treatment with sacubitril/valsartan.

AIMS: Adrenomedullin is a vasodilatory peptide with a role in microcirculatory and endothelial homeostasis. Adrenomedullin is a substrate for neprilysin and may therefore play a role in beneficial effects of sacubitril/valsartan (Sac/Val) treatment. METHODS AND RESULTS: Mid-regional pro-adrenomedullin (MR-proADM) was measured in 156 patients with heart failure with reduced ejection fraction (HFrEF) treated with Sac/Val and 264 patients with heart failure with preserved ejection fraction (HFpEF) randomized to treatment with Sac/Val or valsartan. Echocardiography and Kansas City Cardiomyopathy Questionnaire results were collected at baseline and after 6 and 12 months in the HFrEF cohort. Median (Q1-Q3) baseline MR-proADM concentrations were 0.80 (0.59-0.99) nmol/L in HFrEF and 0.88 (0.68-1.20) nmol/L in HFpEF. After 12 weeks of treatment with Sac/Val, MR-proADM increased by median 49% in HFrEF and 60% in HFpEF, while there were no significant changes in valsartan-treated patients (median 2%). Greater increases in MR-proADM were associated with higher Sac/Val doses. Changes in MR-proADM correlated weakly with changes in N-terminal pro-B-type natriuretic peptide, cardiac troponin T and urinary cyclic guanosine monophosphate. Increases in MR-proADM were associated with decreases in blood pressure, but not significantly associated with changes in echocardiographic parameters or health status. CONCLUSIONS: MR-proAD concentrations rise substantially following treatment with Sac/Val, in contrast to no change from valsartan. Change in MR-proADM from neprilysin inhibition did not correlate with improvements in cardiac structure and function or health status. More data are needed regarding the role of adrenomedullin and its related peptides in the treatment of heart failure. CLINICAL TRIAL REGISTRATION: PROVE-HF ClinicalTrials.gov Identifier: NCT02887183, PARAMOUNT ClinicalTrials.gov Identifier: NCT00887588.