Abstract 205: Dysfunction of the 19S Proteosome Contributes to Adverse Cardiac Remodeling in Mice With Cardiac Restricted Overexpression of Tumor Necrosis Factor

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Wei Wang ◽  
Gabor Szalai ◽  
Natarajan Sivasubramanian ◽  
Douglas L Mann

We have shown previously that mice with cardiac restricted overexression of tumor necrosis factor (sTNF mice) develop progressive cardiac remodeling. Given that the ubiquitin/ proteasome system regulates protein turnover in eukaryotic cells and is thereby a major factor in controlling cell cycle, apoptosis, signal transduction pathways, which are important in cardiac remodeling, the purpose of this study was to assess the function of 19S, 20S and 26S proteasome in sTNF mice and littermate control mice. Results : Activity of the 26S proteasome was significantly suppressed in the hearts of the sTNF mice compared with the wild type littermates, and was detectable as early as 4-weeks of age. To explore the mechanism for the dysfunction of the 26S proteosome, we examined the activity of the 19S and 20S subunits. We observed cleavage of two subunits of the 19S regulatory complex of the proteasome, namely S1 and S10b, in the hearts of the sTNF mice. S1 is involved in the linking of the lid and the base of the 19S complex, while S10b is one of the six ATPase subunits in the base of the 19S complex. Interestingly, we observed that the expression of six subunits of the 20S core complex, β2, β2i, β3, β4, β5, and β7 were up-regulated in the hearts of the sTNF mice compared with the wild type littermate control mice. Despite the higher expression of the six β subunits in the 20S complex, we observed no difference in the 20S proteasome activity in hearts between the sTNF mice and the wild type littermate controls. Conclusion : Taken together, these results suggest that cleavage of S1 and S10b might contribute to the low 26S proteasome activity in the hearts of the sTNF mice. Given that the 26S proteasome is responsible for degrading pro-apoptotic pathways, as well as turning off pro-fibrotic signaling (TGF-beta), these results suggest that dysfunction of the 26S proteasome might be one of the mechanisms underlying left ventricular remodeling in the setting of sustained inflammation.

1999 ◽  
Vol 277 (2) ◽  
pp. H543-H550 ◽  
Author(s):  
Marina R. Bergman ◽  
Ruey H. Kao ◽  
Sylvia A. McCune ◽  
Bethany J. Holycross

Acute increases in blood pressure (BP) increase myocardial tumor necrosis factor (TNF)-α production, but it is not known whether chronic hypertensive stress elevates myocardial TNF-α production, possibly contributing to cardiac remodeling, decreased cardiac function, and faster progression to heart failure. BP, cardiac function, and size were evaluated in normotensive [Sprague-Dawley (SD)], spontaneously hypertensive (SHR), and spontaneously hypertensive heart failure-prone (SHHF) rats at 6, 12, 15, and 18 mo of age and in failing SHHF. Left ventricular tissues were evaluated for secretion of bioactive TNF-α and inhibition of TNF-α secretion by phosphodiesterase inhibitors. All ventricles secreted bioactive and immunoreactive TNF-α, but secretion decreased with age. SHR and SHHF rats secreted more TNF-α than SD rats at 6 mo of age, but only failing SHHF rats secreted significantly more TNF-α at 18 mo. Amrinone inhibited TNF-α secretion in all rats and was less potent but more efficacious than RO-201724 in all strains. TNF-α secretion correlated with BP and left ventricular mass in 6-mo-old rats, but this relationship disappeared with age. Results suggest that hypertension and/or cardiac remodeling is associated with elevated myocardial TNF-α, and, although hypertension, per se, did not maintain elevated cardiac TNF-α levels, SHHF rats increase TNF-α production during the end stages of failure.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Yang Yu ◽  
Baojian Xue ◽  
Hanzeng Li ◽  
Qing Chen ◽  
Mingxuan Li ◽  
...  

TACE is a key metalloprotease involved in ectodomain shedding of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-α. We previously reported that TACE-mediated production of TNF-α in the hypothalamic paraventricular nucleus (PVN) contributes to the sympathetic excitation in heart failure (HF). Additionally, the upregulated TGF-α in the PVN transactivates the epidermal growth factor receptor (EGFR) to activate extracellular signal-regulated kinase (ERK) 1/2 in HF. Here we sought to determine whether central inhibition of TACE attenuates neuroinflammation and prevents the progress of HF. Male rats underwent coronary artery ligation to induce HF or sham surgery (Sham). These rats were treated with bilateral PVN microinjection of a TACE siRNA or control siRNA while some rats received a 4-week intracerebroventricular (ICV) infusion of TACE inhibitor TAPI-0 or vehicle. Compared with Sham rats, HF rats treated with control siRNA, had higher (*P<0.05) levels of TNF-α (7.88±1.32* vs 2.77±0.98 pg/mL) and TGF-α (28.27±2.76* vs 11.62±2.48 pg/mL) in cerebrospinal fluid, and increased mRNA expression of TACE (2.53±0.30* vs 1.04±0.12), TNF-α (3.43±0.55* vs 1.03±0.11), TNF-α receptor 1 (2.32±0.27* vs 1.07±0.19), cyclooxygenase-2 (2.96±0.31* vs 1.10±0.19) and TGF-α (2.68±0.41* vs 1.06±0.14) in the PVN, but these levels were markedly reduced (39-54%*) in TACE siRNA-treated HF rats. Compared with control HF rats, HF rats treated with TACE siRNA had reduced expression of phosphorylated (p-) NF-κB p65 (1.27±0.14 vs 0.84±0.07*), p-EGFR (0.52±0.05 vs 0.37±0.04*) and p-ERK1/2 (1.06±0.10 vs 0.62±0.09*) in the PVN. Moreover, the elevated plasma norepinephrine levels, lung/body weight, heart/body weight and left ventricular (LV) end-diastolic pressure along with decreased LV dP/dt max in HF rats-treated with control siRNA were significantly attenuated in HF rats treated with TACE siRNA. Treatments with TACE siRNA in the PVN also improved the indicators of cardiac hypertrophy and fibrosis of HF. ICV infusion of TAPI-0 had the similar effects with PVN TACE siRNA on these variables in HF. These data indicate that central interventions suppressing TACE activity ameliorate neuroinflammation, sympathetic activation and cardiac dysfunction in HF.


2001 ◽  
Vol 280 (5) ◽  
pp. F777-F785 ◽  
Author(s):  
Guangjie Guo ◽  
Jeremiah Morrissey ◽  
Ruth McCracken ◽  
Timothy Tolley ◽  
Helen Liapis ◽  
...  

Angiotensin II upregulates tumor necrosis factor-α (TNF-α) in the rat kidney with unilateral ureteral obstruction (UUO). In a mouse model of UUO, we found that tubulointerstitial fibrosis is blunted when the TNF-α receptor, TNFR1, is functionally knocked out. In this study, we used mutant mice with UUO in which the angiotensin II receptor AT1a or the TNF-α receptors TNFR1 and TNFR2 were knocked out to elucidate interactions between the two systems. The contribution of both systems to renal fibrosis was assessed by treating TNFR1/TNFR2-double knockout (KO) mice with an angiotensin-converting enzyme inhibitor, enalapril. The increased interstitial volume (Vvint) in the C57BI/6 wild-type mouse was decreased in the AT1a KO from 32.8 ± 4.0 to 21.0 ± 3.7% ( P < 0.005) or in the TNFR1/TNFR2 KO to 22.3 ± 2.1% ( P < 0.005). The Vvint of the TNFR1/TNFR2 KO was further decreased to 15.2 ± 3.7% ( P < 0.01) by enalapril compared with no treatment. The induction of TNF-α mRNA and transforming growth factor-β1 (TGF-β1) mRNA in the kidney with UUO was significantly blunted in the AT1a or TNFR1/TNFR2 KO mice compared with the wild-type mice. Treatment of the TNFR1/TNFR2 KO mouse with enalapril reduced both TNF-α and TGF-β1 mRNA and their proteins to near normal levels. Also, α-smooth muscle actin expression and myofibroblast proliferation were significantly inhibited in the AT1a or TNFR1/TNFR2 KO mice, and they were further inhibited in enalapril-treated TNFR1/TNFR2 KO mice. Incapacitating the angiotensin II or the TNF-α systems individually leads to partial blunting of fibrosis. Incapacitating both systems, by using a combination of genetic and pharmacological means, further inhibited interstitial fibrosis and tubule atrophy in obstructive nephropathy.


Nutrients ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1549 ◽  
Author(s):  
Putcharawipa Maneesai ◽  
Sarawoot Bunbupha ◽  
Prapassorn Potue ◽  
Thewarid Berkban ◽  
Upa Kukongviriyapan ◽  
...  

Hesperidin is a major flavonoid isolated from citrus fruits that exhibits several biological activities. This study aims to evaluate the effect of hesperidin on cardiovascular remodeling induced by n-nitro l-arginine methyl ester (l-NAME) in rats. Male Sprague-Dawley rats were treated with l-NAME (40 mg/kg), l-NAME plus hesperidin (15 mg/kg), hesperidin (30 mg/kg), or captopril (2.5 mg/kg) for five weeks (n = 8/group). Hesperidin or captopril significantly prevented the development of hypertension in l-NAME rats. l-NAME-induced cardiac remodeling, i.e., increases in wall thickness, cross-sectional area (CSA), and fibrosis in the left ventricular and vascular remodeling, i.e., increases in wall thickness, CSA, vascular smooth muscle cells, and collagen deposition in the aorta were attenuated by hesperidin or captopril. These were associated with reduced oxidative stress markers, tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta 1 (TGF-β1), and enhancing plasma nitric oxide metabolite (NOx) in l-NAME treated groups. Furthermore, up-regulation of tumor necrosis factor receptor type 1 (TNF-R1) and TGF- β1 protein expression and the overexpression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) was suppressed in l-NAME rats treated with hesperidin or captopril. These data suggested that hesperidin had cardioprotective effects in l-NAME hypertensive rats. The possible mechanism may involve antioxidant and anti-inflammatory effects.


2000 ◽  
Vol 91 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Kensei Kuroda ◽  
Keizo Miyata ◽  
Yasuo Tsutsumi ◽  
Shinichi Tsunoda ◽  
Koji Nishimura ◽  
...  

Author(s):  
Putcharawipa Maneesai ◽  
Sarawoot Bunbupha ◽  
Prapassorn Potue ◽  
Thewarid Berkban ◽  
Upa Kukongviriyapan ◽  
...  

Hesperidin is a major flavonoid isolated from citrus fruits that exhibits several biological activities. This study aims to evaluate the effect of hesperidin on cardiovascular remodeling induced by N-nitro L-arginine methyl ester (L-NAME) in rats.&nbsp; Male Sprague-Dawley rats were treated with L-NAME (40 mg/kg); L-NAME plus hesperidin (15 mg/kg), or hesperidin (30 mg/kg), or captopril (2.5 mg/kg) for five weeks (n = 8/group). Hesperidin or captopril significantly prevented the development of hypertension in L-NAME rats.&nbsp; Moreover, hesperidin or captopril alleviated L-NAME-induced cardiac remodeling; increases in wall thickness, cross sectional area (CSA) and fibrosis of left ventricular (LV), and vascular remodeling; increases in wall thickness, CSA, vascular smooth muscle cells and collagen deposition in the aorta. These were associated with reduced oxidative stress markers, tumor necrosis factor-alpha (TNF-&alpha;), transforming growth factor-beta 1 (TGF-&beta;1) and enhancing plasma nitric oxide metabolite (NOx) in L-NAME treated groups. Furthermore, up-regulation of tumor necrosis factor receptor type 1 (TNF-R1) and TGF-&beta;1 protein expression and the over-expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) were suppressed in L-NAME rats treated with hesperidin or captopril. These data suggested that hesperidin had cardioprotective effects in L-NAME hypertensive rats. The possible mechanism may involve its antioxidant and anti-inflammatory effects.


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Zhengjia Su ◽  
Shuya Tian ◽  
Wei Liang

This study aimed to investigate the correlation between complement C1q tumor necrosis factor-related protein 1 (CTRP1) and subclinical target organ damage (STOD) in essential hypertension (EH). 720 patients were enrolled in this study, including 360 healthy subjects and 360 patients with EH. The EH group included 183 patients complicated with STOD and 177 patients without STOD. In the STOD group, there were 87 patients with left ventricular hypertrophy (LVH), 32 patients with microalbuminuria (MAU), and 58 patients with complication of LVH and MAU. Enzyme-linked immunosorbent assay (ELISA) was used to detect the CTRP1, adiponectin (APN), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). We found that CTRP1 levels were higher in patients with EH than those in healthy subjects; moreover, the level of CTRP1 of patients in the group complicated with EH and STOD was increased compared with EH patients without STOD. CTRP1 levels in the group complicated with LVH and MAU were significantly higher than those in the LVH group and the MAU group. Furthermore, APN, CTRP1, and IL-6 were three factors that influenced the STOD of EH patients, among which CTRP1 and IL6 were positively related with the complication of hypertension and STOD. In conclusion, CTRP1 levels are increased and associated with the STOD (heart and kidney) in essential hypertension, which can be regarded as a novel biomarker in the prediction of prognosis for patients with essential hypertension.


2004 ◽  
Vol 24 (10) ◽  
pp. 4438-4447 ◽  
Author(s):  
B. Nelson Chau ◽  
Tung-Ti Chen ◽  
Yisong Y. Wan ◽  
James DeGregori ◽  
Jean Y. J. Wang

ABSTRACT The retinoblastoma protein (RB) suppresses cell proliferation and apoptosis. We have previously shown that RB degradation is required for tumor necrosis factor alpha (TNF-α) to induce apoptosis. We show here the identification of two apoptotic effectors, i.e., c-ABL tyrosine kinase and p73, which are activated by TNF-α following RB degradation. In cells expressing a degradation-resistant RB protein (RB-MI), TNF-α does not activate c-ABL. RB-MI also inhibits TNF-α-mediated activation of p73. Genetic deletion and pharmacological inhibition of c-ABL or p73 diminish the apoptotic response to TNF-α in human cell lines and mouse fibroblasts. Thymocytes isolated from RbMI/MI , Abl −/−, or p73 −/− mice are resistant to TNF-α-induced apoptosis compared to their wild-type counterparts. This is in contrast to p53 −/− thymocytes, which exhibit a wild-type level of apoptosis in response to TNF-α. Thus, c-ABL and p73 contribute to apoptosis induced by TNF-α, in addition to their role in promoting DNA damage-associated cell death.


2004 ◽  
Vol 24 (16) ◽  
pp. 7072-7081 ◽  
Author(s):  
Stéphane Gilbert ◽  
Anne Loranger ◽  
Normand Marceau

ABSTRACT Among the large family of intermediate filament proteins, the keratin 8 and 18 (K8/K18) pair constitutes a hallmark for all simple epithelial cells, such as hepatocytes and mammary cells. Functional studies with different cell models have suggested that K8/K18 are involved in simple epithelial cell resistance to several forms of stress that may lead to cell death. We have reported recently that K8/K18-deprived hepatocytes from K8-null mice are more sensitive to Fas-mediated apoptosis. Here we show that upon Fas, tumor necrosis factor alpha receptor, or tumor necrosis factor alpha-related apoptosis-inducing ligand receptor stimulation, an inhibition of extracellular signal-regulated kinase 1 and 2 (ERK1/2) activation sensitizes wild-type but not K8-null mouse hepatocytes to apoptosis and that a much weaker ERK1/2 activation occurs in K8-null hepatocytes. In turn, this impaired ERK1/2 activation in K8-null hepatocytes is associated with a drastic reduction in c-Flip protein, an event that also holds in a K8-null mouse mammary cell line. c-Flip, along with Raf-1, is part of a K8/K18-immunoisolated complex from wild-type hepatocytes, and Fas stimulation leads to further c-Flip and Raf-1 recruitment in the complex. This points to a new regulatory role of simple epithelium keratins in the c-Flip/ERK1/2 antiapoptotic signaling pathway.


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