Plasma Extravasation Research Articles

Gambaran Kadar Hematokrit pada Penderita Demam Berdarah Dengue di RSUD Al – Ihsan

Early signs of dengue virus infection are often nonspecific, which can result in delays in assessment. This disease can develop quickly, even in a matter of days or hours, and can result in serious conditions. The primary pathophysiology of dengue hemorrhagic fever (DHF) involves increased vascular permeability and impaired hemostasis. Increased blood vessel permeability can result in plasma leakage, hypovolemia, and even severe stress. Disturbances in hemostasis can result in thrombocytopenia and bleeding manifestations. In dengue fever sufferers, thrombocytopenia occurs due to antibodies attacking platelets, which make antigen-antibody complexes. Hematocrit levels can increase due to an increase in the number of blood cells or a decrease in the amount of plasma, which often occurs in cases of dengue fever. conversely, hematocrit levels can decrease due to an increase in plasma concentration, similar to the case of a decrease in the number of blood cells or anemia. Blood tests are very crucial in monitoring the patient's condition and determining the prognosis. Based on WHO testing guidelines, thrombocytopenia and plasma extravasation, which are reflected in blood concentrations, are crucial indicators in the assessment of dengue fever. The research method used in this research is narrative, carried out from March to May 2024 at Al-Ihsan Regional Hospital. The study population included 30 patients, and the sample was representative of the entire population. Research findings show that 24 out of 30 patients (80%) experienced an increase in hematocrit levels. Key terms: Dengue Hemorrhagic Fever, Hematocrit.

CXCL5 activates CXCR2 in nociceptive sensory neurons to drive joint pain and inflammation in experimental gouty arthritis.

Gouty arthritis evokes joint pain and inflammation. Mechanisms driving gout pain and inflammation remain incompletely understood. Here we show that CXCL5 activates CXCR2 expressed on nociceptive sensory neurons to drive gout pain and inflammation. CXCL5 expression was increased in ankle joints of gout arthritis model mice, whereas CXCR2 showed expression in joint-innervating sensory neurons. CXCL5 activates CXCR2 expressed on nociceptive sensory neurons to trigger TRPA1 activation, resulting in hyperexcitability and pain. Neuronal CXCR2 coordinates with neutrophilic CXCR2 to contribute to CXCL5-induced neutrophil chemotaxis via triggering CGRP- and substance P-mediated vasodilation and plasma extravasation. Neuronal Cxcr2 deletion ameliorates joint pain, neutrophil infiltration and gait impairment in model mice. We confirmed CXCR2 expression in human dorsal root ganglion neurons and CXCL5 level upregulation in serum from male patients with gouty arthritis. Our study demonstrates CXCL5-neuronal CXCR2-TRPA1 axis contributes to gouty arthritis pain, neutrophil influx and inflammation that expands our knowledge of immunomodulation capability of nociceptive sensory neurons.

Intimomedial tears of the aorta heal by smooth muscle cell-mediated fibrosis without atherosclerosis.

BACKGROUNDDisease of the aorta varies from atherosclerosis to aneurysms, with complications including rupture, dissection, and poorly characterized limited tears. We studied limited tears without any mural hematoma, termed intimomedial tears, to gain insight into aortic vulnerability to excessive wall stresses. Our premise is that minimal injuries in aortas with sufficient medial resilience to prevent tear progression correspond to initial mechanisms leading to complete structural failure in aortas with significantly compromised medial resilience.METHODSIntimomedial tears were macroscopically identified in 9 of 108 ascending aortas after surgery and analyzed by histology and immunofluorescence confocal microscopy.RESULTSNonhemorrhagic, nonatheromatous tears correlated with advanced aneurysmal disease and most lacked distinctive symptoms or radiological signs. Tears traversed the intima and part of the subjacent media, while the resultant defects were partially or completely filled with neointima characterized by differentiated smooth muscle cells, scattered leukocytes, dense fibrosis, and absent elastic laminae despite tropoelastin synthesis. Healed lesions contained organized fibrin at tear edges without evidence of plasma and erythrocyte extravasation or lipid accumulation.CONCLUSIONThese findings suggest a multiphasic model of aortic wall failure in which primary lesions of intimomedial tears either heal if the media is sufficiently resilient or progress as dissection or rupture by medial delamination and tear completion, respectively. Moreover, mural incorporation of thrombus and cellular responses to injury, two historically important concepts in atheroma pathogenesis, contribute to vessel wall repair with adequate conduit function, but even together are not sufficient to induce atherosclerosis.FUNDINGNIH (R01-HL146723, R01-HL168473) and Yale Department of Surgery.

Ethanol Extract of Ampelopsis brevipedunculata Rhizomes Suppresses IgE-Mediated Mast Cell Activation and Anaphylaxis.

More than 20% of the world's population suffers from allergic diseases, including allergic asthma, rhinitis, and atopic dermatitis that severely reduce the patient's quality of life. The treatment of allergy has been developed, but there are still unmet needs. Ampelopsis brevipedunculata (Maxim.) Trautv. is a traditional medicinal herb with beneficial bioactivities, such as antioxidant, anti-hypertension, anti-viral, anti-mutagenic, and skin and liver (anti-hepatotoxic) protective actions. However, its anti-allergic effect has not been addressed. This study designed to investigate the pharmacological effect of an ethanol extract of A. brevipedunculata rhizomes (ABE) on mast cell and anaphylaxis models. For in vivo studies, we used ovalbumin-induced active systemic anaphylaxis (ASA) and immunoglobulin (Ig) E-mediated passive cutaneous anaphylaxis (PCA) models. In ASA model, oral administration of ABE (1, 10, and 100 mg/kg) attenuated the anaphylactic responses, such as hypothermia, serum histamine, and IgE productions. In PCA model, ABE also suppressed the plasma extravasation and swelling. The underlying mechanisms of action were identified in various mast cell types. In vitro, ABE (10, 30, and 60 µg/mL) inhibited the release of essential allergic mediators, such as histamine and β-hexosaminidase, in a concentration-dependent manner. ABE prevented the rapid increase in intracellular calcium levels induced by the DNP-HSA challenge. In addition, ABE downregulated the tumor necrosis factor-α and interleukin-4 by suppressing the activation of nuclear factor-κB. Collectively, this study is the first to identify the anti-allergic effect of ABE, suggesting that ABE is a promising candidate for treating allergic diseases.

Assessing the Impact of Influenza Vaccination Timing on Experimental Arthritis: Effects on Disease Progression and Inflammatory Biomarkers.

Numerous studies have indicated a link between vaccines and the exacerbation of autoimmune diseases including rheumatoid arthritis (RA). However, there is no consensus in clinical practice regarding the optimal timing of immunization. Therefore, this study aimed to investigate the impact of the 3Fluart influenza vaccine on the complete Freund's adjuvant (CFA)-induced chronic arthritis rat model and to identify new biomarkers with clinical utility. CFA was injected into the plantar surface of one hind paw and the root of the tail on day 0, and the tail root injection was repeated on day 1. Flu vaccination was performed on day 1 or 7. Paw volume was measured by plethysmometry, mechanonociceptive threshold by dynamic plantar aesthesiometry, neutrophil myeloperoxidase (MPO) activity, and vascular leakage using in vivo optical imaging throughout the 21-day experiment. Inflammatory markers were determined by Western blot and histopathology. CFA-induced swelling, an increase in MPO activity, plasma extravasation in the tibiotarsal joint. Mechanical hyperalgesia of the hind paw was observed 3 days after the injection, which gradually decreased. Co-administration of the flu vaccine on day 7 but not on day 1 resulted in significantly increased heme oxygenase 1 (HO-1) expression. The influenza vaccination appears to have a limited impact on the progression and severity of the inflammatory response and associated pain. Nevertheless, delayed vaccination could alter the disease activity, as indicated by the findings from assessments of edema and inflammatory biomarkers. HO-1 may serve as a potential marker for the severity of inflammation, particularly in the case of delayed vaccination. However, further investigation is needed to fully understand the regulation and role of HO-1, a task that falls outside the scope of the current study.

Profile of Urticaria and Angioedema Patients at Dr. Moewardi General Hospital Surakarta, Indonesia

Background: Urticaria is a heterogeneous inflammatory skin disease that results from the activation and degranulation of cutaneous mast cells, followed by the release of histamine and other mediators that cause sensory nerve activation, vasodilation, plasma extravasation, and recruitment of immune cells. The prevalence and incidence of urticaria and angioedema have been extensively studied worldwide, but there is still limited data in Indonesia, especially regarding the profile of urticaria and angioedema patients. The purpose of this study was to determine the profile of urticaria and angioedema patients at Dr. Moewardi General Hospital for the period January 1st, 2020 - December 31st, 2022.
 Methods: This study is a cross-sectional retrospective study with secondary data derived from medical records of urticaria and angioedema patients.
 Results: There were 152 patients with urticaria, most of whom were in the age group >60 years (20.39%), female with a male to female ratio of 1:1.92, and worked as housewives (17.76%) and students (16.45%). Most cases were diagnosed with urticaria (86.84%) with some patients having angioedema (13.16%). The most common comorbidities rhinoconjunctivitis (2.63%), atopic dermatitis (1.97%) and asthma (1.32%). The dominant symptoms were itching and bumps (100%). The main treatment received by patients was single AH1 (71.71%) followed by combination therapy of AH1 and systemic corticosteroids (14.47%), combination therapy of AH1 and topical corticosteroids (10.53%), and the rest received combination therapy of AH1, topical corticosteroids, and systemic corticosteroids (3.29%). The skin prick test was positive in 16 patients (35.56%), with the most common allergens found being peanut (37.5%), egg yolk (37.5%), and tomato (37.5%).
 Conclusion: The characteristics of urticaria patients were dominated by elderly patients, female gender, and working as housewives or not working. Patients were predominantly diagnosed with urticaria with the most common comorbidities being diabetes mellitus. The main treatment received was AH1 class drugs. The most common types of allergens identified were peanuts, egg yolks, and tomatoes.

Unlocking endothelial barrier restoration: FX06 in systemic capillary leak syndrome and beyond

Increased vascular permeability is a prevalent feature in a wide spectrum of clinical conditions, but no effective treatments to restore the endothelial barrier are available. Idiopathic systemic capillary leak syndrome (ISCLS) is a life-threatening Paroxysmal Permeability Disorder characterized by abrupt, massive plasma extravasation. This condition serves as a robust model for investigating therapeutic approaches targeting interendothelial junctions. We conducted a single-center, interventional in vitro study at the Referral Center for ISCLS in Italy, involving four diagnosed ISCLS patients, aiming at investigating the effects of FX06, a Bβ15–42 fibrin-derived peptide binding to VE-Cadherin, on endothelial barrier exposed to intercritical and acute ISCLS sera. The Transwell Permeability Assay was used to assess the permeability of human umbilical vein endothelial cells (HUVECs) exposed to ISCLS sera with or without FX06 (50 µg/ml). Acute ISCLS serum was also tested in a three-dimensional microfluidic device. Nitric oxide (NO), VE-Cadherin localization, and cytoskeletal organization were also assessed. In two and three-dimensional systems, ISCLS sera increased endothelial permeability, with a more pronounced effect for acute sera. Furthermore, acute sera altered VE-Cadherin localization and cytoskeletal organization. NO levels remained unchanged. FX06 restored the endothelial barrier function by influencing cellular localization rather than VE-Cadherin levels. In conclusion, FX06 prevents and reverts the hyperpermeability induced by ISCLS sera. These preliminary yet promising results provide initial evidence of the in vitro efficacy of a drug targeting the underlying pathophysiological mechanisms of ISCLS. Moreover, this approach may hold potential for addressing hyperpermeability in a spectrum of clinical conditions beyond ISCLS.

Antinociceptive Efficacy of 15-Deoxy-Δ12,14-Prostaglandin J2 Therapy in Response to Experimentally Induced Temporomandibular Joint Arthritis: A Systematic Review of Studies in Rats

The aim of the present systematic review was to assess the antinociceptive efficacy of 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) therapy in rats with experimentally induced temporomandibular joint (TMJ) arthritis. The focused question was “Is 15d-PGJ2 therapy effective in the management of TMJ nociception?” Indexed databases were searched without time and language restrictions up to and including September 2023 using different key words. Original studies were included. Risk of Bias (RoB) was assessed using the SYRCLE tool. Six studies performed in male Wistar rats with experimentally induced TMJ arthritis were included. The observation or follow-up period ranged between 45 min and 14 days. Four studies reported that 15d-PGJ2 therapy retards the production of proinflammatory cytokines in TMJ tissues. Four studies reported that 15d-PGJ2 therapy inhibits leukocyte migration and plasma extravasation in TMJ tissues. In one study, the expression of decay-accelerating factor in TMJ tissues increased after 15d-PGJ2 therapy. One study showed that 15d-PGJ2 inhibits nociception in a dose-dependent manner via the activation of peripheral kappa/delta opioid receptors. Prior sample-size-estimation (SSE) was performed in none of the studies and all studies had a high RoB. Due to a high RoB, methodological variations, and the absence of prior SSE within the included studies, it is demanding to derive an absolute verdict regarding the antinociceptive efficacy of 15d-PGJ2 therapy in response to experimentally induced TMJ arthritis.

Pharmacologic Inhibition of Transient Receptor Potential Ion Channel Ankyrin 1 Counteracts 2-Chlorobenzalmalononitrile Tear Gas Agent-Induced Cutaneous Injuries.

Deployment of the tear gas agent 2-chlorobenzalmalononitrile (CS) for riot control has significantly increased in recent years. The effects of CS have been believed to be transient and benign. However, CS induces severe pain, blepharospasm, lachrymation, airway obstruction, and skin blisters. Frequent injuries and hospitalizations have been reported after exposure. We have identified the sensory neuronal ion channel, transient receptor potential ankyrin 1 (TRPA1), as a key CS target resulting in acute irritation and pain and also as a mediator of neurogenic inflammation. Here, we examined the effects of pharmacologic TRPA1 inhibition on CS-induced cutaneous injury. We modeled CS-induced cutaneous injury by applying 10 μl CS agent [200 mM in dimethyl sulfoxide (DMSO)] to each side of the right ears of 8- to 9-week-old C57BL/6 male mice, whereas left ears were applied with solvent only (DMSO). The TRPA1 inhibitor HC-030031 or A-967079 was administered after CS exposure. CS exposure induced strong tissue swelling, plasma extravasation, and a dramatic increase in inflammatory cytokine levels in the mouse ear skin. We also showed that the effects of CS were not transient but caused persistent skin injuries. These injury parameters were reduced with TRPA1 inhibitor treatment. Further, we tested the pharmacologic activity of advanced TRPA1 antagonists in vitro. Our findings showed that TRPA1 is a crucial mediator of CS-induced nociception and tissue injury and that TRPA1 inhibitors are effective countermeasures that reduce key injury parameters when administered after exposure. Additional therapeutic efficacy studies with advanced TRPA1 antagonists and decontamination strategies are warranted. SIGNIFICANCE STATEMENT: 2-Chlorobenzalmalononitrile (CS) tear gas agent has been deployed as a crowd dispersion chemical agent in recent times. Exposure to CS tear gas agents has been believed to cause transient acute toxic effects that are minimal at most. Here we found that CS tear gas exposure causes both acute and persistent skin injuries and that treatment with transient receptor potential ion channel ankyrin 1 (TRPA1) antagonists ameliorated skin injuries.

Systemic mapping of organ plasma extravasation at multiple stages of chronic heart failure.

Introduction: Chronic Heart failure (CHF) is a highly prevalent disease that leads to significant morbidity and mortality. Diffuse vasculopathy is a commonmorbidity associated with CHF. Increased vascular permeability leading to plasma extravasation (PEx) occurs in surrounding tissues following endothelial dysfunction. Such micro- and macrovascular complications develop over time and lead to edema, inflammation, and multi-organ dysfunction in CHF. However, a systemic examination of PEx in vital organs among different time windows of CHF has never been performed. In the present study, we investigated time-dependent PEx in several major visceral organs including heart, lung, liver, spleen, kidney, duodenum, ileum, cecum, and pancreas between sham-operated and CHF rats induced by myocardial infarction (MI). Methods: Plasma extravasation was determined by colorimetric evaluation of Evans Blue (EB) concentrations at 3days, ∼10weeks and 4months following MI. Results: Data show that cardiac PEx was initially high at day 3 post MI and then gradually decreased but remained at a moderately high level at ∼10weeks and 4months post MI. Lung PEx began at day 3 and remained significantly elevated at both ∼10weeks and 4months post MI. Spleen PExwas significantly increased at ∼10weeks and 4months but not on day 3 post MI. Liver PEx occurred early at day 3 and remain significantly increased at ∼10weeks and 4months post MI. For the gastrointestinal (GI) organs including duodenum, ileum and cecum, there was a general trend that PEx level gradually increased following MI and reached statistical significance at either 10weeks or 4months post MI. Similar to GI PEx, renal PEx was significantly elevated at 4months post MI. Discussion: In summary, we found that MI generally incites a timedependent PEx of multiple visceral organs. However, the PEx time window for individual organs in response to the MI challenge was different, suggesting that different mechanisms are involved in the pathogenesis of PEx in these vital organs during the development of CHF.

Activation of endothelial TRPM2 exacerbates blood-brain barrier degradation in ischemic stroke.

Damage of the blood-brain barrier (BBB) is a hallmark of brain injury during the early stages of ischemic stroke. The subsequent endothelial hyperpermeability drives the initial pathological changes and aggravates neuronal death. Transient receptor potential melastatin 2 (TRPM2) is a Ca2+-permeable nonselective cation channel activated by oxidative stress. However, whether TRPM2 is involved in BBB degradation during ischemic stroke remains unknown. We aimed to investigate the role of TRPM2 in BBB degradation during ischemic stroke and the underlying molecular mechanisms. Specific deletion of Trpm2 in endothelial cells using Cdh5 Cre produces a potent protective effect against brain injury in mice subjected to middle cerebral artery occlusion (MCAO), which is characterized by reduced infarction size, mitigated plasma extravasation, suppressed immune cell invasion, and inhibited oxidative stress. In vitro experiments using cultured cerebral endothelial cells (CECs) demonstrated that either Trpm2 deletion or inhibition of TRPM2 activation attenuates oxidative stress, Ca2+ overload, and endothelial hyperpermeability induced by oxygen-glucose deprivation (OGD) and CD36 ligand thrombospondin-1 (TSP1). In transfected HEK293T cells, OGD and TSP1 activate TRPM2 in a CD36-dependent manner. Noticeably, in cultured CECs, deleting Trpm2 or inhibiting TRPM2 activation also suppresses the activation of CD36 and cellular dysfunction induced by OGD or TSP1. In conclusion, our data reveal a novel molecular mechanism in which TRPM2 and CD36 promote the activation of each other, which exacerbates endothelial dysfunction during ischemic stroke. Our study suggests that TRPM2 in endothelial cells is a promising target for developing more effective and safer therapies for ischemic stroke.

Aedes aegypti salivary gland extract alleviates acute itching by blocking TRPA1 channels.

Aedes aegypti (Ae. aegypti) saliva induces a variety of anti-inflammatory and immunomodulatory activities. Interestingly, although it is known that mosquito bites cause allergic reactions in sensitised hosts, the primary exposure of humans to Ae. aegypti does not evoke significant itching. Whether active components in the saliva of Ae. aegypti can counteract the normal itch reaction to injury produced by a histaminergic or non-histaminergic pathway in vertebrate hosts is unknown. This study investigated the effects of Ae. aegypti mosquito salivary gland extract (SGE) on sensitive reactions such as itching and associated skin inflammation. Acute pruritus and plasma extravasation were induced in mice by the intradermal injection of either compound 48/80 (C48/80), the Mas-related G protein-coupled receptor (Mrgpr) agonist chloroquine (CQ), or the transient receptor potential ankyrin 1 (TRPA1) agonist allyl isothiocyanate (AITC). The i.d. co-injection of Ae. aegypti SGE inhibited itching, plasma extravasation, and neutrophil influx evoked by C48/80, but it did not significantly affect mast cell degranulation in situ or in vitro. Additionally, SGE partially reduced CQ- and AITC-induced pruritus in vivo, suggesting that SGE affects pruriceptive nerve firing independently of the histaminergic pathway. Activation of TRPA1 significantly increased intracellular Ca2+ in TRPA-1-transfected HEK293t lineage, which was attenuated by SGE addition. We showed for the first time that Ae. aegypti SGE exerts anti-pruriceptive effects, which are partially regulated by the histamine-independent itch TRPA1 pathway. Thus, SGE may possess bioactive molecules with therapeutic potential for treating nonhistaminergic itch.

Systemic Mapping of Organ Plasma Extravasation Post Myocardial Infarction

Chronic Heart failure (CHF) is a highly prevalent disease that leads to significant morbidity and mortality. Diffuse vasculopathy is a common feature of the morbidity associated with CHF. Increased vascular permeability leading to plasma extravasation (PEx) occurs in surrounding tissues following endothelial dysfunction. Such micro- and macro-vascular complications develop over time and lead to edema, inflammation, and multi-organ dysfunction in CHF. However, a systemic examination of PEx in vital organs among different time windows of CHF has never been performed before. In the present study, we investigated time-dependent PEx in several major visceral organs including heart, lung, liver, spleen, kidney, duodenum, ileum, cecum and pancreas between sham-operated and CHF rats induced by myocardial infarction (MI). Plasma extravasation was determined by evaluating Evans Blue concentrations calorimetrically at fluorescence excitation wavelength of 620 nm (bandwidth 10 nm) and an emission wavelength of 680 nm (bandwidth 40 nm) at 3 days, 8-10 weeks and 4 months following MI. Data show that heart PEx level was initially high at day 3 post MI and then gradually decreased but still remained at a moderately high level at 8-10 weeks and 4 months post MI. Lung PEx began at day 3 and remained significantly high at both 8-10 weeks and 4 months post MI. Spleen PEx level was significantly high at 8-10 weeks and 4 months but not day 3 post MI. Liver PEx occurs early at day 3 and remain significantly high at 8-10 weeks and 4 months post MI. For the gastrointestinal (GI) organs including Duodenum, ileum and cecum, there was a general trend that PEx level gradually increased following MI and reached a statistical significance at 4 months post MI. Different with GI PEx, renal PEx level was initially high at day 3 but back to normal level at 8-10 weeks post MI. However, renal PEx was significantly elevated again at 4 months post MI. In summary, we found that MI generally incites a time-dependent PEx of multiple visceral organs. However, the PEx time window for individual organ in response to the MI challenge was different, suggesting that different mechanisms might be involved in the pathogenesis of PEx in these vital organs during CHF. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Efficacy and Safety of Autologous Serum Therapy in Chronic Spontaneous Urticaria in the Pediatric Population: A Prospective Pilot Study.

Chronic spontaneous urticaria (CSU) in children is mostly spontaneous in onset (57%). Treatment comprises long-term antihistaminic therapy without need for elaborate investigations. A subset of such patients don't respond to conventional treatment and novel therapies to help reduce pill burden is the need of the hour. To determine the efficacy and safety of autologous serum therapy (AST) in pediatric patients with chronic spontaneous urticaria. All pediatric patients, aged between 6-16 years, attended to our OPD from March 2019 to March 2020 were recruited. Clinico-demographic data and baseline investigations of all patients were performed. Two-weekly AST therapy was given for 8 visits with levocetrizine tablet 5mg on an on-demand basis. Urticaria activity score (UAS) sheet was provided to record and return every 2 weeks. Statistical analysis was done using the IBM SPSS 26 software package. Autologous serum skin test (ASST) was positive in 63% patients. Both the ASST positive and ASST negative group showed significant reduction in UAS7 score at week 14 compared to baseline. The reduction in mean UAS7 score was associated with a decreased pill burden and positive response in the patient and physician global assessment scale. No statistically significant difference between the two groups in terms of mean UAS7 reduction was found. This study has explored the efficacy and safety of autologous serum therapy in the pediatric CSU patients. Both ASST positive and ASST negative group respond to AST therapy.

Symptoms: Sudden Hearing Loss and Aural Fullness

Symptoms: Sudden Hearing Loss and Aural Fullness

Cardiac sympathetic afferent denervation reduces matrix metalloproteinase expression and improves cardiac remodeling in rats post myocardial infarction

Abstract In a previous study from our laboratory, we demonstrated that chronic and selective cardiac sympathetic afferent (spinal) denervation at the time of myocardial infarction (MI) using epicardial application of resiniferatoxin (RTX), a neuronal toxin capable of inducing rapid degeneration of transient receptor potential vanilloid 1 (TRPV1)-expressing afferent neurons and fibers, markedly reduced the cardiac remodeling process 9–11 weeks post-MI in rats. This included reduced cardiac hypertrophy, fibrosis and apoptosis. Here, we further investigated the effect of epicardial application of RTX at the time of MI on cardiac extracellular matrix (ECM) and remodeling post-MI. Echocardiographic and morphologic data demonstrated that, compared to MI+vehicle, MI+RTX exhibited a significantly slower LV chamber dilation (6-week echocardiographic data: left ventricular end-diastolic diameter, 10.7±0.2 vs. 9.6±0.3 mm; left ventricular end-systolic diameter: 8.8±0.2 vs. 7.8±0.3 mm; MI+vehicle vs. MI+RTX, n=18, p<0.05; mean±SE). Scanning electron microscopy showed that RTX reduced collagen deposition in the peri-infarct area in post-MI rats. Western blot and zymography were used to further evaluate the effect of RTX application on matrix metalloproteinase (MMP) expression and activity, which is responsible for degrading ECM and contributing to cardiac dilation post MI. Our data suggest time-dependent increases in MMP expression in infarcted hearts post MI. RTX application largely prevented the increase in MMP9 but not MMP2, 4 weeks post-MI. RTX prevented both increased MMP2 and MMP9 activities in the peri-infarct myocardium at 8–10 weeks post-MI. We further investigated the effect of RTX application on MI-induced cardiac inflammation, which has been reported as an upstream mechanism triggering MMP activation post-MI. The data show that RTX largely abolished MI-induced plasma extravasation and reduced macrophage infiltration and cardiac cytokine content in the peri-infarct or remote myocardium of post-MI rats. These data suggest that cardiac sympathetic afferent denervation at the time of MI exerts a local anti-inflammatory effect and reduces ECM remodeling by preventing excessive MMP activation in post-MI rats. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health Grant HL126796

Abstract P3002: Endothelial Trpm2 Deletion Attenuates Ischemic Stroke By Preventing Blood-brain Barrier Disruption

Introduction: Endothelial hyperpermeability is a hallmark of brain damage at the early stage of ischemic stroke. The subsequent blood-brain barrier (BBB) disruption drives the initial pathological changes and aggregates neuronal death. Ca 2+ overload is an important cause of endothelial dysfunction. TRPM2 is a Ca 2+ -permeable ion channel activated by oxidative stress, and oxidative stress is a critical contributor for endothelial hyperpermeability during ischemic stroke. Hypothesis: We hypothesized that TRPM2-mediated Ca 2+ influx plays a key role in causing endothelial hyperpermeability during ischemic stroke. Methods: Specific deletion of Trpm2 in endothelial cells was achieved by crossing Cdh5-cre mice with Trpm2 fl/fl mice. Middle cerebral artery occlusion (MCAO) was performed to simulate ischemic stroke. Tetrazolium chloride and Evans blue assays were used to evaluate infarct size and BBB leakage. Occludin and F4-80 / myeloperoxidase staining were used to detect tight junction degradation and immune cell invasion. Cerebral endothelial cells (CECs) were isolated and cultured. Oxygen-glucose deprivation (OGD) was used to simulate in vitro ischemic conditions. In vitro endothelial leakage assays were used to examine CEC permeability. Rhodamine-123 imaging and Ca 2+ imaging were used to evaluate oxidative stress and Ca 2+ overload in CECs. WB was used to examine CD36 signaling activation and whole-cell current recording was used to detect TRPM2 activation. Results: Specific deletion of Trpm2 in endothelial cells protects mice against MCAO-induced brain injury, which is characterized by reduced infarct size, mitigated plasma extravasation, reduced neutrophil / macrophage invasion and inhibited oxidative stress in the brain. In vitro experiments demonstrated that Trpm2 deletion alleviates ROS production, Ca 2+ overload and endothelial hyperpermeability induced by OGD and CD36 ligand thrombospondin-1 (TSP1). In CECs, activation of CD36 signaling induced by OGD and TSP1 was impaired by TRPM2 knockout. In transfected HEK293T cells, OGD and TSP1 induce the activation of TRPM2 currents in a CD36-dependent manner. Conclusion: Endothelial specific TRPM2 knockout attenuates ischemic stroke by preserving BBB integrity.

Management of Acute Episodes of Clarkson Disease (Monoclonal Gammopathy-Associated Systemic Capillary Leak Syndrome) With Intravenous Immunoglobulins.

Monoclonal gammopathy-associated idiopathic systemic capillary leak syndrome (ISCLS, Clarkson disease) is a rare disorder defined by transient but recurrent bouts of hypotensive shock and anasarca resulting from plasma extravasation. Although prophylactic treatment with high-dose intravenous immunoglobulins (IVIG, 1–2 g/kg/mo) prevents most disease flares, its utility for acute episodes of ISCLS is unclear. Here, we report the results of a retrospective study of subjects with acute ISCLS treated at or near the onset of symptoms with IVIG. We found that administration of IVIG with minimal additional intravenous fluids was safe and associated with rapid clinical improvement. IVIG given close to the onset of ISCLS-related symptoms is associated with a favorable outcome.

Bitter taste signaling in tracheal epithelial brush cells elicits innate immune responses to bacterial infection.

Constant exposure of the airways to inhaled pathogens requires efficient early immune responses protecting against infections. How bacteria on the epithelial surface are detected and first-line protective mechanisms are initiated are not well understood. We have recently shown that tracheal brush cells (BCs) express functional taste receptors. Here we report that bitter taste signaling in murine BCs induces neurogenic inflammation. We demonstrate that BC signaling stimulates adjacent sensory nerve endings in the trachea to release the neuropeptides CGRP and substance P that mediate plasma extravasation, neutrophil recruitment, and diapedesis. Moreover, we show that bitter tasting quorum-sensing molecules from Pseudomonas aeruginosa activate tracheal BCs. BC signaling depends on the key taste transduction gene Trpm5, triggers secretion of immune mediators, among them the most abundant member of the complement system, and is needed to combat P. aeruginosa infections. Our data provide functional insight into first-line defense mechanisms against bacterial infections of the lung.

From spreading depolarization to epilepsy with neuroinflammation: The role of CGRP in cortex

CGRP release plays a major role in migraine pain by activating the trigeminal pain pathways. Here we explored putative additional effects of CGRP on cortical circuits and investigated whether CGRP affects cortical excitability, cortical spreading depolarization (CSD), a phenomenon associated with migraine aura, blood-brain-barrier (BBB) and microglial morphology. We used immunohistochemistry to localize CGRP and the CGRP receptor (CGRP-R) in native cortex and evaluated morphology of microglia and integrity of the BBB after exposure to CGRP. In anesthetized rats we applied CGRP and the CGRP-R antagonist BIBN4096BS locally to the exposed cortex and monitored the spontaneous electrocorticogram and CSDs evoked by remote KCl pressure microinjection. In mouse brain slices CGRP effects on neuronal activity were explored by multielectrode array. CGRP immunoreactivity was detectable in intracortical vessels, and all cortical neurons showed CGRP-R immunoreactivity. In rat cortex in vivo, topical CGRP induced periods of epileptiform discharges, however, also dose-dependently reduced CSD amplitudes and propagation velocity. BIBN4096BS prevented these effects. CGRP evoked synchronized bursting activity in mouse cortical but not in cerebellar slices. Topical application of CGRP to rat cortex induced plasma extravasation and this was associated with reduced ramification of microglial cells. From these findings we conclude that CGRP induces a pathophysiological state in the cortex, consisting in neuronal hyperexcitability and neuroinflammation. Thus, CGRP may have a pronounced impact on brain functions during migraine episodes supporting the benefit of CGRP antagonists for clinical use. However, increased cortical CGRP may end the CSD-induced aura phase of migraine.