Abstract 507: Activation of the Classically Pro-Apoptotic Death Receptor 5 Promotes Physiological Hypertrophy and Cardiomyocyte Survival

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Toby Thomas ◽  
Miles Tanner ◽  
Laurel Grisanti

Heart failure is hallmarked by a combination of cardiomyocyte hypertrophy and death. Apoptosis, one of the primary mechanisms of cell death, occurs through finely tuned extrinsic or intrinsic pathways. Of the mediators involved in extrinsic apoptotic signaling, some have been extensively studied, such as tumor necrosis factor ((TNF)-α), while others have been relatively untouched. One such receptor is Death Receptor 5 (DR5) which, along with its ligand TNF-Related Apoptosis Inducing Ligand (TRAIL), have recently been implicated as a biomarker in determining the progression and outcome in patients following multiple heart failure etiologies, suggesting a novel role of DR5 signaling in the heart. These studies suggest a potentially protective role for DR5 in the heart; however, the function of TRAIL/DR5 in the heart has been virtually unstudied. Our goal was to explore the role of TRAIL/DR5 in cardiomyocyte hypertrophy and survival with the hypothesis that DR5 promotes cardiomyocyte survival and growth through non-canonical mechanisms. Mice treated with the DR5 agonist bioymifi or a DR5 agonist antibody, MD5-1, were absent of cell death, while an increase in hypertrophy was observed without a decline in cardiac function. In isolated cardiomyocytes, this pro-hypertrophic phenotype was determined to operate through MMP-dependent cleavage of HB-EGFR, leading to transactivation of EGFR and ERK1/2 signaling. To determine the role of DR5 in heart failure, a chronic catecholamine administration model was used and DR5 activation was found to decrease cardiomyocyte death and cardiac fibrosis. ERK1/2, a well characterized pro-survival, pro-hypertrophic kinase is activated in the heart with DR5 agonist administration and may represent the mechanistic link through which DR5 is imparting cardioprotection. In summary, DR5 activation promotes cardiomyocyte hypertrophy and survival and prevents cardiac fibrosis via a non-canonical MMP-EGFR-ERK1/2 pathway. Taken together, these studies identify a previously undetermined role for DR5 in the heart and identify novel therapeutic target for the treatment of heart failure.

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Walter E Knight ◽  
Masayoshi Oikawa ◽  
Clint Miller ◽  
Chen Yan

The cyclic nucleotides cAMP and cGMP play important roles in mediating both protective and detrimental signaling in heart failure. By acting as regulators of cAMP and cGMP, the phosphodiesterases play important roles in modulating this signaling. A comparison of PDE expression between control mice and mice given transverse aortic constriction revealed that expression of phosphodiesterase 1C (PDE1C) was increased significantly by TAC, both on the mRNA and protein levels. To determine whether this was protective or maladaptive, we performed TAC on mice with a genetic deletion of PDE1C. While TAC-operated WT mice experienced significant overall cardiac hypertrophy and cardiomyocyte hypertrophy, these were reduced in PDE1C KO mice. Cardiac function, as assessed by echocardiography, was also reduced significantly in WT TAC mice, but was preserved in PDE1C KO TAC mice. Histological analysis indicated that TAC-operated PDE1C KO mice also experienced reduced cardiomyocyte apoptosis compared to WT mice, indicating a potential cardioprotective mechanism for PDE1C deletion. Cardiomyocytes isolated from PDE1C KO mice experienced reduced Ang II or Iso-induced cell death compared to WT myocytes, indicating that this was a cardiomyocytes-specific effect of PDE1C deletion. Ang II-induced cardiomyocyte cell death and apoptosis were also blocked via pharmacological PDE1 inhibition. PDE1C is able to hydrolyze either cAMP or cGMP; therefore, it seemed possible that this protective mechanism was dependent on either PKA- or PKG-mediated signaling. While PKG inhibition did not alter the protective effect of PDE1 inhibition in isolated cardiomyocytes, PKA inhibition blocked it. Overexpression studies also indicated that PDE1C is localized to the cell membrane in cardiomyocytes. Therefore, we propose that by modulating a novel, membrane-localized, anti-apoptotic, cAMP/PKA-dependent pathway in cardiomyocytes, PDE1C potentially represents a novel therapeutic target in heart failure.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Flamant ◽  
N. Mougenot ◽  
E. Balse ◽  
L. Le Fèvre ◽  
F. Atassi ◽  
...  

AbstractWe recently highlighted a novel potential protective paracrine role of cardiac myeloid CD11b/c cells improving resistance of adult hypertrophied cardiomyocytes to oxidative stress and potentially delaying evolution towards heart failure (HF) in response to early β-adrenergic stimulation. Here we characterized macrophages (Mφ) in hearts early infused with isoproterenol as compared to control and failing hearts and evaluated the role of upregulated CX3CL1 in cardiac remodeling. Flow cytometry, immunohistology and Mφ-depletion experiments evidenced a transient increase in Mφ number in isoproterenol-infused hearts, proportional to early concentric hypertrophy (ECH) remodeling and limiting HF. Combining transcriptomic and secretomic approaches we characterized Mφ-enriched CD45+ cells from ECH hearts as CX3CL1- and TNFα-secreting cells. In-vivo experiments, using intramyocardial injection in ECH hearts of either Cx3cl1 or Cx3cr1 siRNA, or Cx3cr1−/− knockout mice, identified the CX3CL1/CX3CR1 axis as a protective pathway delaying transition to HF. In-vitro results showed that CX3CL1 not only enhanced ECH Mφ proliferation and expansion but also supported adult cardiomyocyte hypertrophy via a synergistic action with TNFα. Our data underscore the in-vivo transient protective role of the CX3CL1/CX3CR1 axis in ECH remodeling and suggest the participation of CX3CL1-secreting Mφ and their crosstalk with CX3CR1-expressing cardiomyocytes to delay HF.


2021 ◽  
Vol 8 ◽  
Author(s):  
Miles A. Tanner ◽  
Laurel A. Grisanti

The fibrotic response is involved in nearly all forms of heart failure and dysregulated responses can lead to enhanced cardiac dysfunction. TNF-related apoptosis-inducing ligand (TRAIL) and its receptor, death receptor (DR) 5, are associated with multiple forms of heart failure, but their role in the heart is poorly defined. Our previous study identified DR5 expression on cardiac fibroblasts however, the impact of DR5 on fibroblast function remains unexplored. To investigate the role of DR5 in cardiac fibroblasts, a variety of fibroblast functions were examined following treatment with the endogenous ligand, TRAIL, or small molecule agonist, bioymifi. DR5 activation did not induce apoptosis in naïve fibroblasts but activated ERK1/2 signaling to increase proliferation. However, upon activation and differentiation to myofibroblasts, DR5 expression was elevated, and DR5 agonists induced caspase 3 activation resulting in myofibroblast apoptosis. To investigate the impact of DR5 regulation of fibroblasts in vivo, a chronic isoproterenol administration model of heart failure was used. Wild-type (WT) mice receiving isoproterenol had increased hypertrophy, cardiomyocyte death, and fibrosis and decreased contractility compared to vehicle treated animals. DR5 knockout (KO) mice had no overt baseline phenotype however, following isoproterenol infusion, increased cardiomyocyte death and hypertrophy in comparison to isoproterenol treated WT animals was observed. DR5KO mice had an augmented fibrotic response with isoproterenol treatment compared with WT, which corresponded with additional decreases in contractility. These findings identify a dual role for DR5 in cardiac fibroblast function through enhanced naïve fibroblast proliferation, which switches to a pro-apoptotic function upon differentiation to myofibroblasts. This is important in heart failure where DR5 activation suppresses maladaptive remodeling and may represent a novel therapeutic target for the treatment of heart failure.


BMB Reports ◽  
2004 ◽  
Vol 37 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Soo-Mi Kweon ◽  
Zee-Won Lee ◽  
Sun-Ju Yi ◽  
Young-Myeong Kim ◽  
Jeong-A Han ◽  
...  

2020 ◽  
Vol 134 (1) ◽  
pp. 71-72
Author(s):  
Naseer Ahmed ◽  
Masooma Naseem ◽  
Javeria Farooq

Abstract Recently, we have read with great interest the article published by Ibarrola et al. (Clin. Sci. (Lond.) (2018) 132, 1471–1485), which used proteomics and immunodetection methods to show that Galectin-3 (Gal-3) down-regulated the antioxidant peroxiredoxin-4 (Prx-4) in cardiac fibroblasts. Authors concluded that ‘antioxidant activity of Prx-4 had been identified as a protein down-regulated by Gal-3. Moreover, Gal-3 induced a decrease in total antioxidant capacity which resulted in a consequent increase in peroxide levels and oxidative stress markers in cardiac fibroblasts.’ We would like to point out some results stated in the article that need further investigation and more detailed discussion to clarify certain factors involved in the protective role of Prx-4 in heart failure.


2010 ◽  
Vol 6 (2) ◽  
pp. 33 ◽  
Author(s):  
Christopher R deFilippi ◽  
G Michael Felker ◽  
◽  

For many with heart failure, including the elderly and those with a preserved ejection fraction, both risk stratification and treatment are challenging. For these large populations and others there is increasing recognition of the role of cardiac fibrosis in the pathophysiology of heart failure. Galectin-3 is a novel biomarker of fibrosis and cardiac remodelling that represents an intriguing link between inflammation and fibrosis. In this article we review the biology of galectin-3, recent clinical research and its application in the management of heart failure patients.


2021 ◽  
Vol 22 (4) ◽  
pp. 2177
Author(s):  
Shulamit B. Wallach-Dayan ◽  
Dmytro Petukhov ◽  
Ronit Ahdut-HaCohen ◽  
Mark Richter-Dayan ◽  
Raphael Breuer

By dint of the aging population and further deepened with the Covid-19 pandemic, lung disease has turned out to be a major cause of worldwide morbidity and mortality. The condition is exacerbated when the immune system further attacks the healthy, rather than the diseased, tissue within the lung. Governed by unremittingly proliferating mesenchymal cells and increased collagen deposition, if inflammation persists, as frequently occurs in aging lungs, the tissue develops tumors and/or turns into scars (fibrosis), with limited regenerative capacity and organ failure. Fas ligand (FasL, a ligand of the Fas cell death receptor) is a key factor in the regulation of these processes. FasL is primarily found in two forms: full length (membrane, or mFasL) and cleaved (soluble, or sFasL). We and others found that T-cells expressing the mFasL retain autoimmune surveillance that controls mesenchymal, as well as tumor cell accumulation following an inflammatory response. However, mesenchymal cells from fibrotic lungs, tumor cells, or cells from immune-privileged sites, resist FasL+ T-cell-induced cell death. The mechanisms involved are a counterattack of immune cells by FasL, by releasing a soluble form of FasL that competes with the membrane version, and inhibits their cell death, promoting cell survival. This review focuses on understanding the previously unrecognized role of FasL, and in particular its soluble form, sFasL, in the serum of aged subjects, and its association with the evolution of lung disease, paving the way to new methods of diagnosis and treatment.


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Ming Liu ◽  
Zikun Xie ◽  
Guang Sun ◽  
Liujun Chen ◽  
Dake Qi ◽  
...  

Abstract Background Osteoarthritis (OA) is the most prevalent form of arthritis and the major cause of disability and overall diminution of quality of life in the elderly population. Currently there is no cure for OA, partly due to the large gaps in our understanding of its underlying molecular and cellular mechanisms. Macrophage migration inhibitory factor (MIF) is a procytokine that mediates pleiotropic inflammatory effects in inflammatory diseases such as rheumatoid arthritis (RA) and ankylosing spondylitis (AS). However, data on the role of MIF in OA is limited with conflicting results. We undertook this study to investigate the role of MIF in OA by examining MIF genotype, mRNA expression, and protein levels in the Newfoundland Osteoarthritis Study. Methods One hundred nineteen end-stage knee/hip OA patients, 16 RA patients, and 113 healthy controls were included in the study. Two polymorphisms in the MIF gene, rs755622, and -794 CATT5-8, were genotyped using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) and PCR followed by automated capillary electrophoresis, respectively. MIF mRNA levels in articular cartilage and subchondral bone were measured by quantitative polymerase chain reaction. Plasma concentrations of MIF, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) were measured by enzyme-linked immunosorbent assay. Results rs755622 and -794 CATT5-8 genotypes were not associated with MIF mRNA or protein levels or OA (all p ≥ 0.19). MIF mRNA level in cartilage was lower in OA patients than in controls (p = 0.028) and RA patients (p = 0.004), while the levels in bone were comparable between OA patients and controls (p = 0.165). MIF protein level in plasma was lower in OA patients than in controls (p = 3.01 × 10−10), while the levels of TNF-α, IL-6 and IL-1β in plasma were all significantly higher in OA patients than in controls (all p ≤ 0.0007). Multivariable logistic regression showed lower MIF and higher IL-1β protein levels in plasma were independently associated with OA (OR per SD increase = 0.10 and 8.08; 95% CI = 0.04–0.19 and 4.42–16.82, respectively), but TNF-α and IL-6 became non-significant. Conclusions Reduced MIF mRNA and protein expression in OA patients suggested MIF might have a protective role in OA and could serve as a biomarker to differentiate OA from other joint disorders.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Qinghang Liu ◽  
Lei Li ◽  
Yi Chen ◽  
Jessica Doan ◽  
Jeffery Molkentin

We recently identified a novel signaling molecule, TAK1 (TGFβ-activated kinase 1, also known as MAP3K7), as a key regulator of the hypertrophic signaling network. Importantly, TAK1 is activated in mouse models of heart failure as well as in diseased human myocardium. Here, we defined a previously unidentified, novel role for TAK1 in promoting cardiac cell survival and homeostasis using cardiac-specific gene-targeted mice. Indeed, cardiac-specific ablation of TAK1 in mice using a Cre-LoxP system showed enhanced pathological cardiac remodeling and massive cell death, and these mice gradually developed heart failure and spontaneous death. Remarkably, ablation of TNF receptor 1 (TNFR1) largely rescued the pathological phenotype of TAK1-deficient mice, preventing early lethality and cardiac fibrosis, suggesting that TNFR1 signaling is critical in mediating adverse remodeling and heart failure associated with TAK1 deficiency. Genetic or pharmacological inactivation of TAK1 in cardiomyocytes markedly induced programmed necrosis and apoptosis in response to TNFα. Conversely, overexpression of the constitutively active TAK1 mutant, or TAK1 plus its activator TAB1, protected cardiomyocytes from TNFα-induced cell death. Mechanistically, inactivation of TAK1 promoted formation of the necroptotic cell death complex consisting of RIP1, RIP3, caspase 8, and FADD. Genetic ablation of RIP1, RIP3, caspase 8, or FADD largely blocked TNFα-induced cell death in TAK1-deficient cells, whereas deletion of Bax/Bak or cyclophilin D showed no effects. Further, IKK/NFκB-mediated cell survival signaling was greatly impaired in TAK1-deficient cardiomyocytes. Taken together, our data indicate that TAK1 functions as a critical “molecular switch” in TNFα-induced programmed necrosis in cardiomyocytes, by interacting with the RIP1/3-caspase 8-FADD cell death pathway as well as the IKK-NFκB cell survival pathway. These findings thus define an important TAK1-mediated cardio-protective signaling network in the heart, which may suggest new therapeutic strategies in the treatment of heart disease.


2018 ◽  
Vol 20 (1) ◽  
pp. 39 ◽  
Author(s):  
Shih-Kai Chiang ◽  
Shuen-Ei Chen ◽  
Ling-Chu Chang

Heme oxygenase (HO)-1 is known to metabolize heme into biliverdin/bilirubin, carbon monoxide, and ferrous iron, and it has been suggested to demonstrate cytoprotective effects against various stress-related conditions. HO-1 is commonly regarded as a survival molecule, exerting an important role in cancer progression and its inhibition is considered beneficial in a number of cancers. However, increasing studies have shown a dark side of HO-1, in which HO-1 acts as a critical mediator in ferroptosis induction and plays a causative factor for the progression of several diseases. Ferroptosis is a newly identified iron- and lipid peroxidation-dependent cell death. The critical role of HO-1 in heme metabolism makes it an important candidate to mediate protective or detrimental effects via ferroptosis induction. This review summarizes the current understanding on the regulatory mechanisms of HO-1 in ferroptosis. The amount of cellular iron and reactive oxygen species (ROS) is the determinative momentum for the role of HO-1, in which excessive cellular iron and ROS tend to enforce HO-1 from a protective role to a perpetrator. Despite the dark side that is related to cell death, there is a prospective application of HO-1 to mediate ferroptosis for cancer therapy as a chemotherapeutic strategy against tumors.


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