Abstract 5851: Activation of Inflammatory and Apoptotic Pathways in Human Donor Heart Dysfunction

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Christian F Bulcao ◽  
Karen M D’Souza ◽  
Ricky Malhotra ◽  
Michelle Staron ◽  
Prakash K Pandalai ◽  
...  
Keyword(s):  
Heart Disease ◽  
Structural Heart Disease ◽  
Left Ventricular ◽  
Donor Heart ◽  
Stat3 Pathway ◽  
Stat3 Signaling ◽  
Brain Dead ◽  
Phosphorylated Stat3 ◽  
Proapoptotic Gene

Donor heart dysfunction (DHD) precluding procurement for transplantation occurs in up to 25% of brain dead donors in the absence of structural heart disease. The molecular mechanisms of DHD remain unclear. We investigated the potential role of myocardial interleukin (IL)-6 signaling through the JAK2/STAT3 pathway which leads to the generation of nitric oxide (NO) and decreased cardiac myocyte contractility in vitro. NO can also lead to induction of the proapoptotic gene Bnip3 in vitro. Hearts were procured using standard technique with UW solution from 14 brain dead donors with a left ventricular ejection fraction of < 30% (DHD) in the absence of structural heart disease. Six hearts with normal function (NF) that were procured but not transplanted for non-cardiac reasons served as controls. Left ventricular (LV) IL-6 levels were quantitated by ELISA and signaling through the JAK2/STAT3 pathway via IL-6 and gp130 receptors was assessed by expression of activated, or phosphorylated STAT3. NO signaling was measured by myocardial expression of inducible NO synthase (iNOS) and protein immunoblotting for Bnip3 was performed. Myocardial IL-6 protein levels were 8-fold greater in the DHD group vs. NF controls ( P < 0.02). Phosphorylated STAT3 expression was 5-fold higher in DHD vs. NF ( P < 0.01) indicating increased JAK2/STAT3 signaling as there was no difference in total STAT3 expression between groups ( P >0.05). LV expression of iNOS was 2-fold greater in DHD vs. NF ( P < 0.03) consistent with increased iNOS activity. In addition, LV expression of the proapoptotic gene Bnip3 was 3-fold greater in the DHD group vs. NF ( P < 0.04) suggesting that apoptosis may contribute to DHD. N= 14 for DHD and n= 6 for NF in all studies. Increased myocardial IL-6-mediated signaling through the JAK2/STAT3 pathway leading to upregulation of iNOS and NO production may be an important mechanism in human DHD. Increased myocardial NO also appears to lead to upregulation of proapoptotic Bnip3 in cardiac myocytes, and apoptotic cell death may also contribute to ventricular dysfunction following brain death. Inhibition of IL-6/JAK2/STAT3 signaling may represent a novel strategy to increase the severely limited number of cardiac donors.

scholarly journals Clinical Features of LMNA-Related Cardiomyopathy in 18 Patients and Characterization of Two Novel Variants

2021 ◽  
Vol 10 (21) ◽  
pp. 5075
Author(s):  
Valentina Ferradini ◽  
Joseph Cosma ◽  
Fabiana Romeo ◽  
Claudia De Masi ◽  
Michela Murdocca ◽  
...  
Keyword(s):  
Heart Disease ◽  
Functional Characterization ◽  
Clinical Manifestations ◽  
Structural Heart Disease ◽  
Left Ventricular ◽  
Dermal Fibroblasts ◽  
Lamin A ◽  
Lmna Gene

Dilated cardiomyopathy (DCM) refers to a spectrum of heterogeneous myocardial disorders characterized by ventricular dilation and depressed myocardial performance in the absence of hypertension, valvular, congenital, or ischemic heart disease. Mutations in LMNA gene, encoding for lamin A/C, account for 10% of familial DCM. LMNA-related cardiomyopathies are characterized by heterogeneous clinical manifestations that vary from a predominantly structural heart disease, mainly mild-to-moderate left ventricular (LV) dilatation associated or not with conduction system abnormalities, to highly pro-arrhythmic profiles where sudden cardiac death (SCD) occurs as the first manifestation of disease in an apparently normal heart. In the present study, we select, among 77 DCM families referred to our center for genetic counselling and molecular screening, 15 patient heterozygotes for LMNA variants. Segregation analysis in the relatives evidences other eight heterozygous patients. A genotype–phenotype correlation has been performed for symptomatic subjects. Lastly, we perform in vitro functional characterization of two novel LMNA variants using dermal fibroblasts obtained from three heterozygous patients, evidencing significant differences in terms of lamin expression and nuclear morphology. Due to the high risk of SCD that characterizes patients with lamin A/C cardiomyopathy, genetic testing for LMNA gene variants is highly recommended when there is suspicion of laminopathy.

scholarly journals Role of Stat3 Signaling in Control of EMT of Tubular Epithelial Cells During Renal Fibrosis

2017 ◽  
Vol 42 (6) ◽  
pp. 2552-2558 ◽  
Author(s):  
Jingsong Liu ◽  
Ying Zhong ◽  
Guoyong Liu ◽  
Xiaobai Zhang ◽  
Bofei Xiao ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Renal Injury ◽  
Renal Fibrosis ◽  
Critical Role ◽  
Dependent Manner ◽  
Tubular Epithelial Cells ◽  
Mesenchymal Transition ◽  
Stat3 Signaling ◽  
Phosphorylated Stat3

Background/Aims: Transforming growth factor β 1 (TGFβ1) plays a critical role in the epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (TECs) during renal injury, a major cause of acute renal failure, renal fibrosis and obstructive nephropathy. However, the underlying molecular mechanisms remain ill-defined. Here, we addressed this question. Methods: Expression of TGFβ1, Snail, and phosphorylated Stat3 was examined by immunohistochemistry in the kidney after induction of unilateral ureteral obstruction (UUO) in mice. In vitro, primary TECs were purified by flow cytometry, and then challenged with TGFβ1 with/without presence of specific inhibitors for phosphorylation of SMAD3 or Stat3. Protein levels were determined by Western blotting. Results: We detected significant increases in Snail and phosphorylated Stat3, an activated form for Stat3, in the kidney after induction of UUO in mice. In vitro, TGFβ1-challenged primary TECs upregulated Snail, in a SMAD3/Stat3 dependent manner. Conclusion: Our study sheds light on the mechanism underlying the EMT of TECs after renal injury, and suggests Stat3 signaling as a promising innovative therapeutic target for prevention of renal fibrosis.

scholarly journals Antiarrhythmic Medication for Atrial Fibrillation (AIM-AF) study: A physician survey of antiarrhythmic drug (AAD) treatment practices and guideline adherence in the EU and USA

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
AJ Camm ◽  
C Blomstrom-Lundqvist ◽  
G Boriani ◽  
A Goette ◽  
PR Kowey ◽  
...  
Keyword(s):  
Heart Disease ◽  
Structural Heart Disease ◽  
Left Ventricular ◽  
Rhythm Control ◽  
Left Ventricular Ejection ◽  
Primary Therapy ◽  
Physician Survey ◽  
Treatment Practices ◽  
The Usa ◽  
The Eu

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Sanofi Introduction The 2020 European Society of Cardiology and the 2019 USA (AHA/ACC/HRS) guidelines recommend the use of AADs for rhythm control in patients with symptomatic AF. This study sought to understand AAD treatment practices and adherence to guidelines across the EU and the USA. Method An online physician survey of cardiologists, cardiac electrophysiologists and interventional electrophysiologists (N = 569) was conducted in the USA, Germany, Italy and the UK. All respondents were actively treating ≥10 AF patients who received drug therapy and/or who had received or were referred for ablation. This extensively detailed survey explored questions on physician demographics, AF types, and drug treatment and ablation practices. Results: Of the responses obtained (1) Amiodarone was used frequently across co-morbidity categories (highest use in those with heart failure with reduced left ventricular ejection fraction [LVEF] [80%]), including in those in which it is not indicated for initial therapy (minimal or no structural heart disease: 26%). Other deviations from guideline recommendations, include: class 1C drugs were used with structural heart disease, including coronary artery disease (CAD) (average class 1C use in CAD-related comorbidities: 6%); sotalol was used with renal dysfunction (22%); and drugs such as sotalol and dofetilide were initiated out of hospital (56% and 17% of respondents, respectively). (2) Nonetheless, a majority of respondents (53%) considered guidelines as the most important non-patient factor in influencing their choice of AF management. (3) Rhythm control was selected more frequently as primary therapy for paroxysmal AF (PAF) (59% of patients) while rate control was used more often for persistent AF (53%). (4) For PAF, AADs were preferred as 1st line more often than ablation, especially if PAF was infrequent and mildly symptomatic (59% of respondents) while ablation was preferred more if frequent symptomatic PAF and for recurrent persistent AF. (5) Rhythm control (AAD or ablation) was chosen in notable numbers for asymptomatic AF and subclinical AF (AADs: 36% and 37%, respectively; ablation: 9% and 14%, respectively). (6) AAD use for those with a first or recurrent episodes of symptomatic AF was 60% or 47%, respectively. (7) Efficacy and safety were chosen as the most important considerations for choice of specific rhythm control therapy (49% and 33%, respectively), and reduction of mortality and cardiovascular hospitalisation (23%) were as important as maintaining sinus rhythm (26%) for rhythm therapy goals. Conclusions Although surveyed clinicians consider guidelines important, deviations in patient types and treatments chosen that compromise safety or were not indicated were common. Findings suggest a lack of understanding of the pharmacology and safe use of AADs, highlighting an important need for further education. Abstract Figure.

scholarly journals Dl-3-n-Butylphthalide Alleviates Hippocampal Neuron Damage in Chronic Cerebral Hypoperfusion via Regulation of the CNTF/CNTFRα/JAK2/STAT3 Signaling Pathways

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenxian Li ◽  
Di Wei ◽  
Zheng Zhu ◽  
Xiaomei Xie ◽  
Shuqin Zhan ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Signaling Pathways ◽  
Neuronal Death ◽  
Neuronal Apoptosis ◽  
Vascular Cognitive Impairment ◽  
Chronic Cerebral Hypoperfusion ◽  
Cerebral Hypoperfusion ◽  
Stat3 Pathway ◽  
Stat3 Signaling

Chronic cerebral hypoperfusion (CCH) contributes to cognitive impairments, and hippocampal neuronal death is one of the key factors involved in this process. Dl-3-n-butylphthalide (D3NB) is a synthetic compound originally isolated from the seeds of Apium graveolens, which exhibits neuroprotective effects against some neurological diseases. However, the protective mechanisms of D3NB in a CCH model mimicking vascular cognitive impairment remains to be explored. We induced CCH in rats by a bilateral common carotid artery occlusion (BCCAO) operation. Animals were randomly divided into a sham-operated group, CCH 4-week group, CCH 8-week group, and the corresponding D3NB-treatment groups. Cultured primary hippocampal neurons were exposed to oxygen-glucose deprivation/reperfusion (OGD/R) to mimic CCH in vitro. We aimed to explore the effects of D3NB treatment on hippocampal neuronal death after CCH as well as its underlying molecular mechanism. We observed memory impairment and increased hippocampal neuronal apoptosis in the CCH groups, combined with inhibition of CNTF/CNTFRα/JAK2/STAT3 signaling, as compared with that of sham control rats. D3NB significantly attenuated cognitive impairment in CCH rats and decreased hippocampal neuronal apoptosis after BCCAO in vivo or OGD/R in vitro. More importantly, D3NB reversed the inhibition of CNTF/CNTFRα expression and activated the JAK2/STAT3 pathway. Additionally, JAK2/STAT3 pathway inhibitor AG490 counteracted the protective effects of D3NB in vitro. Our results suggest that D3NB could improve cognitive function after CCH and that this neuroprotective effect may be associated with reduced hippocampal neuronal apoptosis via modulation of CNTF/CNTFRα/JAK2/STAT3 signaling pathways. D3NB may be a promising therapeutic strategy for vascular cognitive impairment induced by CCH.

scholarly journals Janus Kinase Inhibition Ameliorates Ischemic Stroke Injury and Neuroinflammation Through Reducing NLRP3 Inflammasome Activation via JAK2/STAT3 Pathway Inhibition

2021 ◽  
Vol 12 ◽  
Author(s):  
Hua Zhu ◽  
Zhihong Jian ◽  
Yi Zhong ◽  
Yingze Ye ◽  
Yonggang Zhang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Tissue ◽  
Proinflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Immunofluorescence Staining ◽  
Western Blots ◽  
Stat3 Pathway ◽  
Stat3 Signaling

BackgroundInflammatory responses play a multiphase role in the pathogenesis of cerebral ischemic stroke (IS). Ruxolitinib (Rux), a selective oral JAK 1/2 inhibitor, reduces inflammatory responses via the JAK2/STAT3 pathway. Based on its anti-inflammatory and immunosuppressive effects, we hypothesized that it may have a protective effect against stroke. The aim of this study was to investigate whether inhibition of JAK2 has a neuroprotective effect on ischemic stroke and to explore the potential molecular mechanisms.MethodsRux, MCC950 or vehicle was applied to middle cerebral artery occlusion (MCAO) mice in vivo and an oxygen-glucose deprivation/reoxygenation (OGD/R) model in vitro. After 3 days of reperfusion, neurological deficit scores, infarct volume and brain water content were assessed. Immunofluorescence staining and western blots were used to measure the expression of NLRP3 inflammasome components. The infiltrating cells were investigated by flow cytometry. Proinflammatory cytokines were assessed by RT-qPCR. The expression of the JAK2/STAT3 pathway was measured by western blots. Local STAT3 deficiency in brain tissue was established with a lentiviral vector carrying STAT3 shRNA, and chromatin immunoprecipitation (ChIP) assays were used to investigate the interplay between NLRP3 and STAT3 signaling.ResultsRux treatment improved neurological scores, decreased the infarct size and ameliorated cerebral edema 3 days after stroke. In addition, immunofluorescence staining and western blots showed that Rux application inhibited the expression of proteins related to the NLRP3 inflammasome and phosphorylated STAT3 (P-STAT3) in neurons and microglia/macrophages. Furthermore, Rux administration inhibited the expression of proinflammatory cytokines, including TNF-α, IFN-γ, HMGB1, IL-1β, IL-2, and IL-6, suggesting that Rux may alleviate IS injury by inhibiting proinflammatory reactions via JAK2/STAT3 signaling pathway regulation. Infiltrating macrophages, B, T, cells were also reduced by Rux. Local STAT3 deficiency in brain tissue decreased histone H3 and H4 acetylation on the NLRP3 promoter and NLRP3 inflammasome component expression, indicating that the NLRP3 inflammasome may be directly regulated by STAT3 signaling. Rux application suppressed lipopolysaccharide (LPS)-induced NLRP3 inflammasome secretion and JAK2/STAT3 pathway activation in the OGD/R model in vitro.ConclusionJAK2 inhibition by Rux in MCAO mice decreased STAT3 phosphorylation, thus inhibiting the expression of downstream proinflammatory cytokines and the acetylation of histones H3 and H4 on the NLRP3 promoter, resulting in the downregulation of NLRP3 inflammasome expression.

scholarly journals Epigenetic Silencing of Tumor Suppressor miR-124 Directly Supports STAT3 Activation in Cutaneous T-Cell Lymphoma

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2692
Author(s):  
Lidia García-Colmenero ◽  
Jéssica González ◽  
Juan Sandoval ◽  
Yolanda Guillén ◽  
Angel Diaz-Lagares ◽  
...  
Keyword(s):  
T Cell ◽  
Ectopic Expression ◽  
Tumor Stage ◽  
Stat3 Pathway ◽  
Stat3 Signaling ◽  
T Cell Lymphomas ◽  
Pathway Activation ◽  
Pathway Regulation ◽  
Genetic Signatures ◽  
Phosphorylated Stat3

Increasing evidence supports a potential role for STAT3 as a tumor driver in cutaneous T-cell lymphomas (CTCL). The mechanisms leading to STAT3 activation are not fully understood; however, we recently found that miR-124, a known STAT3 regulator, is robustly silenced in MF tumor-stage and CTCL cells. Objective: We studied here whether deregulation of miR-124 contributes to STAT3 pathway activation in CTCL. Methods: We measured the effect of ectopic mir-124 expression in active phosphorylated STAT3 (p-STAT3) levels and evaluated the transcriptional impact of miR-124-dependent STAT3 pathway regulation by expression microarray analysis. Results: We found that ectopic expression of miR-124 results in massive downregulation of activated STAT3 in different CTCL lines, which resulted in a significant alteration of genetic signatures related with gene transcription and proliferation such as MYC and E2F. Conclusions: Our study highlights the importance of the miR-124/STAT3 axis in CTCL and demonstrates that the STAT3 pathway is regulated through epigenetic mechanisms in these cells. Since deregulated STAT3 signaling has a major impact on CTCL initiation and progression, a better understanding of the molecular basis of the miR-124/STAT3 axis may provide useful information for future personalized therapies.

scholarly journals Echocardiographic Predictors of Ventricular Tachycardia

2014 ◽  
Vol 8s4 ◽  
pp. CMC.S18499 ◽  
Author(s):  
John N. Catanzaro ◽  
John N. Makaryus ◽  
Amgad N. Makaryus ◽  
Cristina Sison ◽  
Christos Vavasis ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ventricular Tachycardia ◽  
Left Atrial ◽  
Structural Heart Disease ◽  
Left Ventricular ◽  
Pharmacologic Therapy ◽  
Cardioverter Defibrillator ◽  
First Occurrence ◽  
Echocardiographic Parameters

Background Patients with structural heart disease are prone to ventricular tachycardia (VT) and ventricular fibrillation (VF), which account for the majority of sudden cardiac deaths (SCDs). We sought to examine echocardiographic parameters that can predict VT as documented by implantable cardioverter-defibrillator (ICD) appropriate discharge. We examine echocardiographic parameters other than ejection fraction that may predict VT as recorded via rates of ICD discharge. Methods Analysis of 586 patients (469 males; mean age = 68 ± 3 years; mean follow-up time of 11 ± 14 months) was undertaken. Echo parameters assessed included left ventricular (LV) internal end diastolic/systolic dimension (LVIDd, LVIDs), relative wall thickness (RWT), and left atrial (LA) size. Results The incidence of VT was 0.22 (114 VT episodes per 528 person-years of follow-up time). Median time-to-first VT was 3.8 years. VT was documented in 79 patients (59 first VT incidence, 20 multiple). The echocardiographic parameter associated with first VT was LVIDs >4 cm ( P = 0.02). Conclusion The main echocardiographic predictor associated with the first occurrence of VT was LVIDs >4 cm. Patients with an LVIDs >4 cm were 2.5 times more likely to have an episode of VT. Changes in these echocardiographic parameters may warrant aggressive pharmacologic therapy and implantation of an ICD.

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