bluuebunny/crossref_metadata_2025_split huggingface dataset:
AT1 receptor on glutamatergic neurons regulate cardiac function through modulation of excitability and sympathetic outflow
Authors: Xu Jiaxi , Molinas Adrien , Zsombok Andrea , Lazartigues Eric 
Published: November 2023

Previously we generated a mouse model with Angiotensin (Ang)‐II type 1 (AT1) receptor deletion from the central nervous system (CNS) neurons. Compared to their control littermates, those mice exhibited attenuated hypertension and improved autonomic function after DOCA‐salt treatment (DOCA 1mg/g body weight sc + 1% saline po for 3 weeks). Moreover, unlike controls, no increase in left ventricle (LV) mass or decrease in cardiac systolic function was observed, suggesting those mice with neuronal AT1R deficiency were protected from the cardio‐hypertrophic process induced by DOCA‐salt treatment, indicating a possible role of neuronal AT1R in regulation of cardiac function. To further investigate this hypothesis, a new mouse model (AT1G) was generated, in which AT1aR was knocked‐out from glutamatergic neurons. Interestingly, at baseline, AT1G mice (n=7) already exhibit impaired cardiac function, as reflected by reductions in ejection fraction (−11.63 ±3.95%; P=0.0048) and fractional shortening (−6.61 ±2.25%; P=0.0049), despite no significant changes in morphology (such as LV mass, chamber size, and wall thickness). Blood pressure (BP) and heart rate (HR) were also unaltered even though spontaneous baroreflex sensitivity was slightly reduced (2.31 ±0.29 vs. 3.01 ±0.23 msec/mmHg, P=0.04). After 2 weeks of DOCA‐salt treatment (n=5/group), control mice exhibited a significant decrease in cardiac systolic function (P=0.01) and increase in the LV chamber size (P<0.01), which were not observed in DOCA‐salt‐treated AT1G mice. Moreover, when echocardiography was performed (14 day of DOCA‐salt treatment), there was no significant difference in BP and HR between AT1G mice and their control littermates, both of which were hypertensive due to DOCA‐salt treatment (127.3 ±8.89 vs. 131.5 ±1.84, P=0.27), suggesting the change in cardiac function is mediated directly by the CNS and not secondary to a BP rise. To further dissect the mechanism, qRT‐PCR and patch‐clamp recording were performed. In the hypothalamus of AT1G mice, mRNA levels for GABAA receptors and glutamic acid decarboxylase (GAD) 67 were significantly higher, by +52 ±17% and +36 ±14% respectively, compared to controls (n=4/group, P<0.01). Meanwhile, lower action potential (AP) frequency was recorded in kidney‐related PVN neurons of AT1G mice (0.43 ±0.06 vs. 2.04±0.96 Hz, n=3, P=0.01), suggesting that those neurons indeed have lower excitability compared to controls. Altogether, our data provide evidence that central renin‐angiotensin system has an essential role in regulating cardiac function by mediating neuronal excitability and sympathetic outflow.Support or Funding InformationThis work was supported by research grants from the National Institutes to Health (HL093178 and GM106392 to E.L.) and The American Heart Association to E.L. (12EIA8030004), J.X. (15POST25000010).
Blunted respiratory responses in the STZ‐induced rat model of Alzheimer's disease
Authors: Ebel Dalton Louis , Torkilsen Christopher G , Ostrowski Tim Daniel 
Published: November 2023

Alzheimer's disease (AD) is a debilitating disease of the central nervous system that results in a drastic decline in cognition and memory. In addition, respiratory dysfunction is frequently observed in AD patients, as shown by altered breathing during sleep and blunted minute ventilation during heightened oxygen demand with peak exercise. The combination of AD symptoms leads to a decrease in day‐to‐day function and increased mortality. At this time, the mechanisms behind the respiratory alterations are widely unknown.For this study, an AD rat model was induced by injecting 1.5 mg/kg Streptozotocin (STZ) in the lateral ventricle to trigger pathological changes consistent with sporadic AD. We used plethysmography to analyze the peripheral and central chemoreflex in response to hypoxia (14 ‐ 8% O2, equilibrated with N2) or hypercapnia (5% CO2, equilibrated with O2), respectively. We compared respiratory parameters before and after injection of STZ or vehicle (aCSF). Morphological changes in the brainstem and hippocampus were immunohistochemically analyzed using an antibody against S‐100B for astrocytes.Similar to the inflammation in the CNS of AD patients, microinjection of STZ induced astrogliosis in the CA1 region of the hippocampus. We also found reactive astrocytes in the commissural part of the nucleus tractus solitarii, an important center for the control of respiration and responses to low oxygen conditions. In comparison, astrocytes in the pre‐Bötzinger complex of AD rats did not change. Analyzing the respiratory pattern, we found an expected age‐dependent decrease in minute ventilation in our control group. This age‐dependent decrease was absent in the AD group, indicating elevated minute ventilation following STZ administration. Peripheral chemoreflex activation with hypoxia showed significant alterations in the AD group, as observed by a blunted elevation of respiratory rate and minute ventilation. Central chemoreflex activation with hypercapnia only decreased respiratory rate following STZ.We show that the STZ‐induced AD rat model displays significant respiratory dysfunction at rest and in response to hypoxia. Thus, this study provides the first model to elucidate the mechanisms behind respiratory dysfunction of sporadic Alzheimer's disease.
An intrinsic tryptophan metabolite acts as pulmonary vasodilator in pulmonary hypertension
Authors: Nagy Bence , Nagaraj Chandran , Meinitzer Andreas , Papp Rita , Foris Vasile , Ghanim Bahil , Kwapiszewska Grazyna , Kovacs Gabor , Klepetko Walter , Pieber Thomas R. , Mangge Harald , Olschewski Horst , Olschewski Andrea 
Published: November 2023

The tryptophan metabolite kynurenine is associated with pulmonary hypertension (PH) in dyspnea patients and is increased in PH. In addition, it causes dilation in systemic arteries. Our aim was to investigate the role of kynurenine in the pulmonary circulation.Serum tryptophan, kynurenine and kynurenic‐acid levels were measured in 20 IPAH patients, 20 healthy controls and 20 patients with chronic lung disease or metabolic syndrome without PH. Laser‐dissected pulmonary arteries from IPAH and control lungs were tested for the expression of IDO, the enzyme responsible for tryptophan‐kynurenine conversion. Acute effects of kynurenine were tested in pulmonary vascular preparations, two different models of chronic PH, and in human pulmonary arterial smooth muscle cells (hPASMC).Among all investigated tryptophan metabolites, the strongest association to PH was found with kynurenine. In IPAH vs. control, kynurenine was significantly elevated (3.6±0.2μM vs. 2.6±0.1μM, p<0.0001), and strongly associated with PH (AUC=0.86), but kynurenine levels were not elevated in lung disease‐ and metabolic syndrome‐patients. Kynurenine displayed strongest correlation with mean pulmonary arterial pressure (mPAP) (ρ:0.770, p<0.0001). Tryptophan was significantly decreased in IPAH however, IDO expression was not changed. In hPASMCs, kynurenine increased both cAMP and cGMP; in the rat and mouse it relaxed preconstricted intrapulmonary arteries; and in two models of established PH it acutely decreased mPAP.Our data suggest that kynurenine elevation might be specifically associated with mPAP; kynurenine increases both cAMP and cGMP in hPASMC and it exerts acute pulmonary vasodilatation. Kynurenine might provide both a new biomarker for PH and a new therapeutic option.
Microparticles from Aged Stored Platelets Impair Microvascular Pulmonary Endothelial Cell Barrier Function
Authors: McVey Mark J , Maishan Mazharul , Srbely Victoria , Lee Warren , Spring Chris , Semple John , Kuebler Wolfgang M 
Published: November 2023

BACKGROUNDTransfusion‐related acute lung injury (TRALI) has a mortality of 5–15% and an incidence ranging from 0.02–1%. TRALI causes chest infiltrates and hypoxia in part due to lung endothelial cell (EC) barrier failure and edema formation. Aged platelets which have a high risk of causing TRALI, accumulate microparticles (PMPs) throughout storage. PMPs have been shown to mediate pro‐inflammatory processes such as neutrophil priming.RESEARCH QUESTIONConsidering the role of ECs in TRALI, we set out to determine if aged platelet derived PMPs could mediate EC barrier disruption?HYPOTHESISSpecifically, we hypothesized that PMPs from aged but not fresh platelets will lead to EC monolayer disruption.METHODSC57BL/6 mouse platelets were stored for 1 (fresh) or 5 (aged) days duration prior to PMP isolation (centrifugation/filtration) and enumeration (flow cytometry). Human microvascular pulmonary ECs (passage 6–8) were cultured with PBS (sham) or 0.1 mg/ml LPS two hours prior to addition of PBS, 5×105 of fresh or aged PMPs, or PMP depleted supernatants from stored platelet pools. Transendothelial electrical resistance (TEER) readings were obtained every 30 minutes for 8 hours in triplicate. Alternatively aged 10 ml/kg PMPs (≈ 5×106) or saline (sham) was transfused into primed (2 mg/kg LPS intraperitoneal) BALB/c mice for assessment of lung tissue wet‐to‐dry (W/D) ratios 6 hours post transfusion.RESULTSPMPs were found to be increased more than 2 fold in aged as compared to fresh platelet storage pools. ECs exposed to LPS alone did not reveal decreases in TEER relative to PBS sham. When aged PMPs were added 2 hours after PBS there was a marked drop in TEER within 2 hours which became maximal (nearly 50% decrease relative to PBS alone) by 5 hours. Addition of LPS instead of PBS prior to aged PMPs led to similar decreases in TEER readings but with faster onset. Addition of platelet and PMP depleted supernatants (fresh or aged) or fresh PMPs with LPS did not show signs of decreased TEER readings relative to PBS sham. Beyond being more numerous, aged PMPs appear more injurious than fresh PMPs when delivered in our EC model at identical doses. Aged PMPs are able to reduce EC monolayer integrity within 2 hours and sustain this effect for up to 6 hours +/− LPS. LPS primed mice transfused aged PMPs had higher W/D ratios than LPS primed mice transfused saline (p<0.05).CONCLUSIONSPMPs may in part contribute to TRALI when aged platelets which are a rich source of PMPs are transfused. In our model aged PMPs were injurious, impairing EC barrier integrity in vitro and leading to increased W/D ratios in vivo. Targeting aged PMPs may prove a therapeutic option to reduce the risk of aged cellular blood products from causing TRALI.Support or Funding InformationCanadian Institutes of Health Research (CIHR)Canadian Blood Services (CBS)
Novel PKA‐mediated mechanisms of microvascular endothelial barrier enhancement
Authors: Batori Robert Karoly , Kumar Sanjiv , Shaw Mary , Bordan Zsuzsanna , Gorshkov Boris , Kovacs‐Kasa Anita , Fulton David , Verin Alexander 
Published: November 2023

Acute lung injury (ALI) is devastating disorder with an unacceptably high level of mortality. The pharmacological treatment of ALI relies on supportive care and control of initiating causes. Therefore, novel therapies are urgently needed to improve clinical outcomes. Endothelial cells (EC) form a semi‐permeable barrier between the interior space of blood vessels and the underlying tissues. ALI is characterized by significant pulmonary inflammatory response resulting in a protein‐rich pulmonary edema due to the loss of endothelial barrier integrity. The mechanisms that govern increased EC permeability are under intense investigation, however, the processes determining the preservation/restoration of the EC barrier function remain poorly understood. Our group has previously shown that extracellular purines, ATP and adenosine are able to preserve vascular barrier in murine model of LPS‐induced ALI and enhance EC barrier in human pulmonary artery EC (HPAEC) via activation of myosin light chain (MLC) phosphatase (MLCP). MLCP activation may involve PKA‐dependent phosphorylation of the MLCP targeting subunit 1 (MYPT1) at S695, which may activate MLCP directly or indirectly by preventing its Rho kinase‐mediated phosphorylation of the subsequent T696 residue, however, the direct link between MLCP, PKA and purine‐induced EC barrier enhancement was not established.Our new data demonstrated that stable ATP analog, ATPγS, is able to strengthen the EC barrier in human lung microvascular EC (HLMVEC). In contrast to ATP, this effect is not accompanied by an inflammatory response but involved PKA activation and decrease in MLC20 phosphorylation suggesting the involvement of MLCP. Surprisingly, in contrast to adenosine, ATPγS‐induced PKA activation does not acompanied by increase in cAMP level suggesting the existance of an unconventional cAMP‐independent model of PKA activation. Further, ATPγS‐induced EC barrier strengthening is not involved EPAC1, but dependent upon a non‐receptor type 11 tyrosine‐phosphatase (PTPN11, also known as Shp2) and AKAP2 (PKA anchoring protein 2) expression. Furher, we demonstrated that AKAP2 can directly interact with MYPT1 and depletion of AKAP2 restored MLC20 phosphorylation level reduced by ATPγS treatment. Collectively, our data suggest that ATPγS‐, but not adenosine‐induced EC barrier enhancement requires coordinated Shp2‐mediated activation of PKA which is then guided by AKAP2 to activate MLCP and dephosphorylate MLC.Support or Funding InformationSupported by HL101902
Paternal Hyperandrogenism Promotes Behavioral Changes in Swiss Mice Offspring
Authors: Conceição Rodrigo Rodrigues , Souza Janaina Sena , Laureano‐Melo Roberto , Lau Raphael Silva , da Rocha Natalino Monteiro Livia , Dos‐Santos Raoni Conceição , da Silva Almeida Claudio , Giannocco Gisele , da Silva Cortes Wellington 
Published: November 2023

The paternal environmental factors before conception and during sperm development determine the health of the offspring in later life. Thus, the aim of our study was to verify how paternal hyperandrogenism is able to change behavioral parameters in mice's offspring during adulthood. For this purpose, two groups (n=6 each, and ~35g) of male Swiss mice were randomly divided into two groups. The control was treated with peanut oil, while the treated group received testosterone cypionate (7.5mg/kg, s.c.) twice a week for five weeks. After this period, these animals were mated and the offspring obtained, by completing 70 days of life, were underwent to a battery tests consisting of the following tests: open field, dark‐light box, elevated plus maze and tail suspension test. At the end of the experiment, hippocampus was dissected for RNA analysis. Statistical analysis was performed by t‐Student and the means were considered significantly different when p<0.05. According to our results, the treated group had higher immobility time in tail suspension test (28%, p=0.02) and decreased opened arms time in elevated plus maze test (27%, p=0.01). Moreover, in light‐dark box test, the treated group offspring had less time in the light side than control (156%, p=0.002). These behavioral changes were accompanied by reduced GAD 67 (17%, p = 0.01) and BDNF (37%, p = 0.005) expression, as well as a higher GABAA receptor α2 subunit (50%, p = 0.03) expression in hippocampus. These findings indicate that paternal hyperandrogenism alters hippocampal neurotrophin and gabaergic system, promoting anxiety and depression‐like behaviors in adults. Also, these results are of important significance when we consider the abusive use of anabolic steroids for fitness purposes.Support or Funding InformationFAPERJ & CNPq.
Determining the Contribution of Mast Cell‐specific Neurokinin‐1 Receptors in Pressure Overload‐Induced Cardiac Fibrosis
Authors: Widiapradja Alexander , Manteufel Edward , Pena James , Goldspink Paul , Sharma Amit , Imig John D , Lu Bao , Levick Scott 
Published: November 2023

Substance P (SP) and mast cells (MCs) both play a detrimental role in initiating myocardial remodeling, including fibrosis, in response to pressure overload. However, it is not known whether MC activation is an underlying mechanism mediating the effects of SP in this setting. We sought to determine whether SP and its cognate receptor, the neurokinin‐1 receptor (NK‐1R), regulate MC function and whether this is a mechanism underlying the pro‐fibrotic actions of SP. Administration of the NK‐1R antagonist, L732138 to spontaneous hypertensive rats (SHR) reduced cardiac MC density by reducing levels of stem cell factor (SCF), which promotes MC proliferation and maturation. SP treatment of bone marrow derived mast cells (BMMCs), as a model of cardiac MCs, showed no change in c‐kit levels (SCF receptor) or apoptosis, ruling out the possibility of SP/NK‐1R in regulating MC number through increasing the response to SCF or via altering apoptosis. Interestingly, SP activation of the NK‐1R does not activate MCs since conditioned media from SP treated MCs had no effect on collagen synthesis by cultured fibroblasts, and reconstitution of MC‐deficient mice with MCs lacking the NK‐1R did not reduce cardiac fibrosis in angiotensin II‐infused mice. Further, whilst SCF is important in MC proliferation, it also does not activate MCs as there was no increase in cardiac collagen in SCF injected mice. In conclusion, SP activation of the NK‐1R increases MC density in the overloaded heart via production of SCF, however, neither SP nor SCF activate MCs in this setting. Thus, the stimulus activating MCs in the setting of cardiac fibrosis is still unknown.Support or Funding InformationNational Institutes of Health HL093215 (S.P.L.), HL132908 (S.P.L.), Greater Milwaukee Foundation–Elsa Schoeneich Medical Research Fund (S.P.L.), MCW Presidential Postdoctoral Fellow Award (A.W.).
Administration of anti‐inflammatory interleukin‐37 ameliorates age‐related vascular, metabolic and physical dysfunction in mice
Authors: Sapinsley Zachary J , Ballak Dov B , Brunt Vienna E , Zigler Melanie C , Gioscia‐Ryan Rachel A , Richey James J , Dinarello Charles A , Seals Douglas R 
Published: November 2023

Chronic, low‐grade inflammation that occurs with age, termed inflammaging, is a key mechanism in the etiology of age‐related disease and dysfunction, which has been linked to the pathophysiology of cardiovascular diseases, metabolic diseases including type 2 diabetes mellitus, and physical decline. Interleukin‐37 (IL‐37), a member of the interleukin‐1 family of cytokines, broadly inhibits inflammation and therefore carries strong potential as an anti‐aging intervention.PURPOSEWe tested the hypothesis that two weeks of recombinant IL‐37 (recIL‐37) administration would improve vascular, metabolic, and motor function in old mice.METHODSTwenty old (27 mo) and fourteen young (9–10 mo) male C57BL/6 mice were treated with recIL‐37 or vehicle (phosphate buffered saline) for two weeks, injected intraperitoneally (IP) (200μL of 5μg/L) daily. Vascular, metabolic, and motor functions were measured at baseline and again post‐intervention using blood pressure and large elastic artery stiffness testing with pulse wave velocity, 2‐hr glucose and insulin tolerance tests, and RotaRod endurance run time, respectively. Vascular function was further evaluated through ex vivo carotid artery endothelium‐dependent dilation to increasing doses of acetylcholine (10−9 to 10−4 M) without and with nitric oxide (NO) synthase inhibition via 10−4M L‐NG‐nitroarginine methyl ester (L‐NAME).RESULTSTwo weeks of recIL‐37 administration in old mice: (1) improved ex vivo endothelium‐dependent dilation of carotid arteries (p < 0.05 for 10−7 to 10−5M ACh, n=7–9 per group; 10−5M ACh: recIL‐37: 86.2±2.7%max vs. vehicle: 64.6±3.0%max, p=0.01) seemingly by improving NO‐dependent dilation (difference between dilation to max ACh dose without and with L‐NAME: recIL‐37: 67.4±7%max vs. vehicle 50.5±5.3%max, p=0.08, n=6 per group); (2) improved insulin sensitivity (2‐hr glucose AUC following IP insulin injection [0.75U/kg body weight], recIL‐37: 232±23 mM·min vs. vehicle: 293±17 mM·min, p=0.05) and tended to improve glucose tolerance in a subset of mice (20‐min peak blood glucose following IP glucose injection [2μg/g body weight], recIL‐37: 10.4±0.8mM vs. vehicle: 13.3±1.2mM, p=0.08), and (3) completely restored RotaRod endurance run time (recIL‐37: 36±7 m vs. vehicle: 17±7, p=0.03) to levels comparable to young vehicle‐treated mice (34±8m, P=0.86 vs. old recIL‐37). No changes were observed in blood pressure or pulse wave velocity or in any variables in young mice.CONCLUSIONSTwo‐week administration of anti‐inflammatory recIL‐37 improves selective vascular, metabolic, and motor functions in old mice. Anti‐inflammatory treatments such as recIL‐37 present a novel strategy for preserving physiological function with advancing age and preventing age‐related diseases.Support or Funding InformationSupported by NIA grant #RAG053804A.
RORγt‐Dependent Pro‐inflammatory Cytokine IL‐17F in SHR Impairs Endothelium‐Dependent Vascular Relaxation
Authors: Singh Madhu V. , Cicha Michael Z. , Kumar Santosh , Irani Kaikobad , Chapleau Mark W. , Abboud François M. 
Published: November 2023

We have previously shown that SHR (spontaneously hypertensive rat) have an abnormally large population of CD161+ immune cells that express RORγt (retinoic acid receptor related orphan receptor gamma) transcription factor. RORγt is the master regulator of T helper 17 (Th17) cell differentiation of CD4+ naive T cells that express CD161, IL‐17A and IL‐17F. This CD161+ abundance in the SHR spleen increases with age and produces a potent pro inflammatory cytokine IL‐17F in a RORγt‐dependent manner. In this study, we tested whether the enhanced inflammatory response seen in splenocytes is manifested in the vascular tissue of the SHR and contributes to a pathological response. We determined CD161+ cell infiltration of the aorta by flow cytometry and measured changes in RNA expression by real time quantitative PCR. We also performed wire myography on aortic rings to determine the effect of IL‐17F on vasorelaxation. We found significantly greater infiltration of CD161+ cells in age‐matched SHR aorta than in WKY (0.2% in WKY vs. 6.2% in SHR), whereas total CD4+ cell infiltration was not different (15.1% in WKY vs. 14.2% in SHR). Upon ex vivo treatment of aorta with phorbol 12‐myristate 13‐acetate (PMA) and ionomycin to induce cytokine production, both WKY and SHR showed increased IL‐17A RNA expression (1.6 fold in WKY vs. 2.4 fold in SHR), whereas IL‐17F expression was increased to a much greater extent in SHR aorta than in WKY (7.9 fold in WKY vs. 15.3 fold in SHR, P<0.05). These results are consistent with our previous findings of greater IL‐17F induction in SHR immune cells. Furthermore, we found that PMA‐ionomycin induces a modest increase in IL‐17A RNA expression in the peri‐vascular adipose tissue (PVAT) of both WKY and SHR (1.7 fold in WKY vs. 2.9 fold in SHR) with a much larger increase in IL‐17F RNA in SHR PVAT (2.8 fold in WKY vs. 13.9 fold in SHR, P<0.05). Treatment of aortic rings from WKY rats with IL‐17F, but not IL‐17A, impaired endothelium‐dependent relaxation of preconstricted vessels by acetylcholine in a dose‐dependent manner. The treatment did not affect endothelium‐independent, sodium nitroprusside‐induced vasorelaxation. We conclude that in SHR, a genetically predisposed abundance of CD161+ immune cells leads to a greater infiltration of these cells in the vasculature and increased potential for IL‐17F production. Moreover, IL‐17F impairs endothelium‐dependent vascular relaxation, a function previously unknown that would contribute to vascular pathology in SHR.Support or Funding InformationNIH Program Project Grant to FMA (HL 14388) VA Merit Review Award to MWC (1I01BX001414), and AHA Innovative Research Grant to MVS (16IRG27260323).