Serine Mutations in Hsp27 abrogate its ability to inhibit p53 dependent apoptosis and Doxorubicin-induced Heart Failure in mice

Author(s):  
Ragu Kanagasabai ◽  
Krishnamurthy Karthikeyan ◽  
Jay L. Zweier ◽  
Govindasamy Ilangovan

Small heat shock proteins (sHsps) protect the heart from chemotherapeutics-induced heart failure, by inhibiting p53-dependant apoptosis. However, mechanism of such protection has not been elucidated yet. Here we test a hypothesis that serine phosphorylation of sHsps is essential to inhibit the Doxorubicin-induced p53-dependent apoptotic pathway. Three transgenic mice (TG) lines with cardiomyocyte specific overexpression of human heat shock protein 27 (hHsp27), namely, wild type (MHC-hHsp27), S82A single mutant (MHC-mut-hHsp27(S82A) and tri-mutant (MHC-mut-hHsp27(S15A/S78A/S82A)) were generated. TG mice were treated with Dox (6mg/kg body weight; once in a week; 4 weeks) along with age-matched non-transgenic (Non-TG) controls. The Dox-treated MHC-hHsp27 mice showed improved survival and cardiac function (both MRI and echocardiography), in terms of contractility (%EF) and left ventricular inner diameter (LVID), compared to the Dox-treated Non-TG mice. However, both MHC-mut-hHsp27(S82A) and MHC-mut-hHsp27(S82A/S15A/S76A) mutants overexpressing TG mice did not show such a cardioprotection. Furthermore, transactivation of p53 was found to be attenuated only in Dox-treated MHC-hHsp27 mice-derived cardiomyocytes in vitro, as low p53 was detected in the nuclei, not in mutant hHsp27 overexpressing cardiomyocytes. Similarly, only in MHC-hHsp27 overexpressing cardiomyocytes, low Bax, higher mTOR phosphorylation and low apoptotic PARP-1 cleavage (89kDa fragment) were detected. Pharmacological inhibition of p53 was more effective in mutant-TG mice, compared to MHC-hHsp27 mice. We conclude that phosphorylation of overexpressed Hsp27 at S82 and its association with p53 is essential for the overall cardioprotective effect of Hsp27 against Dox-induced dilated cardiomyopathy. Only phosphorylated Hsp27 protect the heart by inhibiting p53 transactivation.

2014 ◽  
Vol 21 (6) ◽  
pp. 564-571 ◽  
Author(s):  
Sourav Roy ◽  
Monobesh Patra ◽  
Suman Nandy ◽  
Milon Banik ◽  
Rakhi Dasgupta ◽  
...  

Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 471-477
Author(s):  
J Roger H Frappier ◽  
David B Walden ◽  
Burr G Atkinson

Abstract Etiolated maize radicles (inbred Oh43) subjected to a brief heat shock synthesize a family of small heat shock proteins (≃18 kD) that is composed of at least 12 members. We previously described the cDNA-derived sequence of three maize shsp mRNAs (cMHSP18-1, cMHSP18-3, and cMHSP18-9). In this report, we demonstrate that the mRNA transcribed in vitro from one of these cDNAs (cMHSP 18-9) is responsible for the synthesis of three members of the shsp family, and we suggest that cMHSP18-3 may be responsible for the synthesis of three additional members and cMHSP18-1 for the synthesis of two other members of this family. The fact that these genes do not contain introns, coupled with the observations reported herein, suggest that maize may have established another method of using a single gene to produce a number of different proteins.


2001 ◽  
Vol 280 (3) ◽  
pp. C614-C620 ◽  
Author(s):  
Chantal Colmont ◽  
Stéphanie Michelet ◽  
Dominique Guivarc'h ◽  
Germain Rousselet

Urea, with NaCl, constitutes the osmotic gradient that allows water reabsorption in mammalian kidneys. Because NaCl induces heat shock proteins, we tested the responses to heat shock of mIMCD3 cells adapted to permissive urea and/or NaCl concentrations. We found that heat-induced cell death was stronger after adaptation to 250 mM urea. This effect was reversible, dose dependent, and, interestingly, blunted by 125 mM NaCl. Moreover, we have shown that urea-adapted cells engaged in an apoptotic pathway upon heat shock, as shown by DNA laddering. This sensitization is not linked to a defect in the heat shock response, because the induction of HSP70 was similar in isotonic and urea-adapted cells. Moreover, it is not linked to the presence of urea inside cells, because washing urea away did not restore heat resistance and because applying urea and heat shock at the same time did not lead to heat sensitivity. Together, these results suggest that urea modifies the heat shock response, leading to facilitated apoptosis.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Findlay ◽  
J.H Gill ◽  
R Plummer ◽  
C.J Plummer

Abstract   Anthracycline chemotherapy remains a key component of cancer treatment regimens in both paediatric and adult patients. A significant issue with their use is the development of anthracycline-induced cardiotoxicity (AIC), with subclinical AIC and clinical heart failure observed in 13.8% and 3.1% of patients, respectively. The major clinical complication of AIC is the development of late-onset cardiotoxicity, occurring several years after drug administration, presenting as life-threatening heart failure (HF). Determining the relationship between subclinical AIC and late-onset HF, strategies for mitigation of AIC, and impacts upon the cancer survivor population remains a complex challenge. Administration of drugs targeting the angiotensin system, specifically angiotensin converting enzyme inhibitors (ACEi), have been reported to reduce AIC in the clinic. Whilst the therapeutic effect of ACEi in management of left ventricular systolic dysfunction and consequent HF is principally through optimisation of cardiac haemodynamics, the mechanism involved with mitigation of late-onset AIC several years after anthracycline exposure are currently unknown. Using a variety of human cardiomyocyte in vitro models we have previously demonstrated induction of cardiomyocyte hypertrophy by angiotensin II and anthracyclines. Importantly, selective blockade of the angiotensin II receptor 1 (ATR1) on cardiomyocytes mitigated the anthracycline-induced hypertrophic response, implicating synergism between AIC and angiotensin signalling in cardiomyocytes. Adult human ventricular cardiac myocyte AC10 cell-line were treated in vitro with a range of clinically relevant doxorubicin doses for clinically appropriate durations, with AT1 receptor gene expression evaluated using semi-quantitative PCR. Our results confirm a positive correlation between clinically-relevant concentration of doxorubicin and induction of genetic expression of ATR1 in AC10 cells, with up to 200% increases in ATR1 expression observed. Maximal doxorubicin-induced gene expression being observed at 8 and 24-hours, respectively. These preliminary results agreeing with clinical exposure parameters for this drug with protein expression studies being optimised to support these gene expression study results. Our preliminary studies also imply patients developing AIC carry a deleted polymorphism within intron 16 of the ACE gene and increased systemic levels of the ACE product angiotensin II, both with a known association to hypertrophic cardiomyopathy. Taken together, these data support our mechanistic hypothesis that a relationship exists between AIC and modulation of the angiotensin signalling pathway in cardiomyocytes, involving structural cellular changes and asymptomatic cardiac hypertrophy. An elevation in angiotensin II levels, potentially through polymorphisms in ACE, could thereby exacerbate anthracycline-induced hypertrophy and promote the development of late-onset anthracycline-induced HF. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Cancer Research UK funded PhD


2021 ◽  
Vol 22 (7) ◽  
pp. 3700
Author(s):  
Junna Hayashi ◽  
Jennifer Ton ◽  
Sparsh Negi ◽  
Daniel E. K. M. Stephens ◽  
Dean L. Pountney ◽  
...  

Oxidation of the neurotransmitter, dopamine (DA), is a pathological hallmark of Parkinson’s disease (PD). Oxidized DA forms adducts with proteins which can alter their functionality. αB-crystallin and Hsp27 are intracellular, small heat-shock molecular chaperone proteins (sHsps) which form the first line of defense to prevent protein aggregation under conditions of cellular stress. In vitro, the effects of oxidized DA on the structure and function of αB-crystallin and Hsp27 were investigated. Oxidized DA promoted the cross-linking of αB-crystallin and Hsp27 to form well-defined dimer, trimer, tetramer, etc., species, as monitored by SDS-PAGE. Lysine residues were involved in the cross-links. The secondary structure of the sHsps was not altered significantly upon cross-linking with oxidized DA but their oligomeric size was increased. When modified with a molar equivalent of DA, sHsp chaperone functionality was largely retained in preventing both amorphous and amyloid fibrillar aggregation, including fibril formation of mutant (A53T) α-synuclein, a protein whose aggregation is associated with autosomal PD. In the main, higher levels of sHsp modification with DA led to a reduction in chaperone effectiveness. In vivo, DA is sequestered into acidic vesicles to prevent its oxidation and, intracellularly, oxidation is minimized by mM levels of the antioxidant, glutathione. In vitro, acidic pH and glutathione prevented the formation of oxidized DA-induced cross-linking of the sHsps. Oxidized DA-modified αB-crystallin and Hsp27 were not cytotoxic. In a cellular context, retention of significant chaperone functionality by mildly oxidized DA-modified sHsps would contribute to proteostasis by preventing protein aggregation (particularly of α-synuclein) that is associated with PD.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Sven T Pleger ◽  
Changguang Shan ◽  
Jan Kziencek ◽  
Oliver Mueller ◽  
Raffi Bekeredjian ◽  
...  

Background: Cardiac expression of the Ca-dependent inotropic protein S100A1 is decreased in human end-stage heart failure (HF) and cardiomyocyte-targeted viral-based S100A1 gene transfer rescued failing myocardium in small animal models in vivo and in vitro via improved systolic and diastolic sarcoplasmic reticulum Ca-handling. We therefore hypothesized that cardioselective AAV9-S100A1 gene therapy will improve cardiac performance in a large animal experimental HF model under clinical conditions. Methods and Results: Left ventricular (LV) posterolateral myocardial infarction (MI) was induced in pigs by occlusion of the left coronary circumflex artery and resulted in LV failure (HF) 2 weeks post-MI reflected by a 40% and 27% reduction in LV +dp/dt max. and EF, respectively, as assessed by LV catheterization and echocardiography. Post-MI HF pigs were then randomized for retroinfusion of AAV9-luciferase (luc; n=6, 1.5×10 13 total viral particles, tvp) and AAV9-S100A1 (S100A1; n=6, 1.5×10 13 tvp) driven by a cardioselective promoter via the anterior cardiac vein while the left anterior descending artery was temporarily occluded. 14 weeks after cardiac gene transfer, the S100A1-treated HF group showed significantly enhanced S100A1 protein expression (+46.7±17.9%, P<0.05 vs. control groups) in targeted remote LV myocardium and improved indices of cardiac function and remodeling (luc vs. S100A1: +dp/dtmax: 983±81 vs. 1526±83 mmHg/s, EF: 39±2.1 vs. 61±3.7 %, P<0.05 S100A1 vs. luc, LV endsystolic diameter: luc 4.45±0.1 vs. S100A1 3.43 ±0.1 cm, P<0.05 S100A1 vs. luc, HR: 72±4 vs. 69±2, beats/min, P=n.s. S100A1 vs. luc). Importantly, analyses of renal, hepatic and hematopoetic function showed no alteration as assessed by unchanged transaminases, retention values and white blood cell counts compared to sham pigs. Conclusions: Our translational study provides proof of concept that AAV9-S100A1 based HF gene therapy is feasible and restores cardiac function in a large animal HF model under clinical conditions. Next, certified toxicological analysis and different AAV9-S100A1 dosage protocols will be assessed to eventually advance to first phase I/II clinical studies determining therapeutic efficiency of cardiac S100A1 gene therapy in HF patients.


2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Jordan Lancaster ◽  
Elizabeth Juneman ◽  
Nicholle Johnson ◽  
Joseph Bahl ◽  
Steven Goldman

Background: Cell-based regenerative therapies hold promise as a new treatment for heart failure. Tissue engineered scaffolds used for cell delivery enhance potential improvements in cardiac function by providing the structural and nutrient support for transplanted cell survival, integration, and re-population of injured tissues. Previously, our laboratory reported improvements in left ventricular (LV) function in rats with chronic heart failure (CHF) after placement of a neonatal cardiomyocyte (NCM) seeded 3-dimensional fibroblast construct (3DFC). In brief, 3 weeks after implantation of the NCM-3DFC, LV function improves by increasing (p<0.05) ejection fraction 26% and cardiac index 33%, while decreasing (p<0.05) LV end diastolic pressure 38%. The current report focuses on NCM survival and LV improvements out to 7 weeks post NCM-3DFC implantation. Methods and Results: Cardiomyocytes were isolated from neonatal rat hearts and seeded onto a 3DFC. We evaluated NCM-3DFC in vitro for cellular organization and the presence of functional gap junctions, which demonstrated extensive cell-to-cell connectivity. At 5 days in culture, the seeded patch contracted spontaneously in a rhythmic and directional fashion, beating at 43±3 beats/min with a mean displacement of 1.3±0.3 mm and contraction velocity of 0.8±0.2 mm/sec. The seeded patch could be electrically paced at near physiological rates (270±30 beats/min) while maintaining coordinated, directional contractions. For in vivo evaluation, rats underwent coronary artery ligation and allowed to recover for 3 weeks to establish CHF. NCM-3DFC were implanted 3 weeks after ligation and evaluated 3 and 7 weeks later (6 and 10 weeks after ligation respectively). Live cell tracking of implanted NCM using Q-Dots revealed ∼9% survival of transplanted cells 3 weeks after implantation. In addition, improvements in LV function continued at 7 weeks after implantation of the NCM-3DFC by increasing (p<0.05) ejection fraction 37%. Conclusion: A multicellular, electromechanically organized, cardiomyocyte scaffold, engineered in vitro can improve LV function when implanted directly on the hearts of rats with CHF; the transplanted cells survive and improve LV function chronically.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Andrea Iorga ◽  
Rangarajan Nadadur ◽  
Salil Sharma ◽  
Jingyuan Li ◽  
Mansoureh Eghbali

Heart failure is generally characterized by increased fibrosis and inflammation, which leads to functional and contractile defects. We have previously shown that short-term estrogen (E2) treatment can rescue pressure overload-induced decompensated heart failure (HF) in mice. Here, we investigate the anti-inflammatory and anti-fibrotic effects of E2 on reversing the adverse remodeling of the left ventricle which occurs during the progression to heart failure. Trans-aortic constriction procedure was used to induce HF. Once the ejection fraction reached ∼30%, one group of mice was sacrificed and the other group was treated with E2 (30 αg/kg/day) for 10 days. In vitro, co-cultured neonatal rat ventricular myocytes and fibroblasts were treated with Angiotensin II (AngII) to simulate cardiac stress, both in the presence or absence of E2. In vivo RT-PCR showed that the transcript levels of the pro-fibrotic markers Collagen I, TGFβ, Fibrosin 1 (FBRS) and Lysil Oxidase (LOX) were significantly upregulated in HF (from 1.00±0.16 to 1.83±0.11 for Collagen 1, 1±0.86 to 4.33±0.59 for TGFβ, 1±0.52 to 3.61±0.22 for FBRS and 1.00±0.33 to 2.88±0.32 for LOX) and were reduced with E2 treatment to levels similar to CTRL. E2 also restored in vitro AngII-induced upregulation of LOX, TGFβ and Collagen 1 (LOX:1±0.23 in CTRL, 6.87±0.26 in AngII and 2.80±1.5 in AngII+E2; TGFβ: 1±0.08 in CTRL, 3.30±0.25 in AngII and 1.59±0.21 in AngII+E2; Collagen 1: 1±0.05 in CTRL.2±0.01 in AngII and 0.65±0.02 (p<0.05, values normalized to CTRL)). Furthermore, the pro-inflammatory interleukins IL-1β and IL-6 were upregulated from 1±0.19 to 1.90±0.09 and 1±0.30 to 5.29±0.77 in the in vivo model of HF, respectively, and reversed to CTRL levels with E2 therapy. In vitro, IL-1β was also significantly increased ∼ 4 fold from 1±0.63 in CTRL to 3.86±0.14 with AngII treatment and restored to 1.29±0.77 with Ang+E2 treatment. Lastly, the anti-inflammatory interleukin IL-10 was downregulated from 1.00±0.17 to 0.49±0.03 in HF and reversed to 0.67±0.09 in vivo with E2 therapy (all values normalized to CTRL). This data strongly suggests that one of the mechanisms for the beneficial action of estrogen on left ventricular heart failure is through reversal of inflammation and fibrosis.


2001 ◽  
Vol 281 (3) ◽  
pp. H1346-H1352 ◽  
Author(s):  
Karyn L. Hamilton ◽  
Scott K. Powers ◽  
Takao Sugiura ◽  
Sunjoo Kim ◽  
Shannon Lennon ◽  
...  

We examined the effects of 3 days of exercise in a cold environment on the expression of left ventricular (LV) heat shock proteins (HSPs) and contractile performance during in vivo ischemia-reperfusion (I/R). Sprague-Dawley rats were divided into the following three groups ( n = 12/group): 1) control, 2) exercise (60 min/day) at 4°C (E-Cold), and 3) exercise (60 min/day) at 25°C (E-Warm). Left anterior descending coronary occlusion was maintained for 20 min, followed by 30 min of reperfusion. Compared with the control group, both the E-Cold and E-Warm groups maintained higher ( P < 0.05) LV developed pressure, first derivative of pressure development over time (+dP/d t), and pressure relaxation over time (−dP/d t) throughout I/R. Relative levels of HSP90, HSP72, and HSP40 were higher ( P < 0.05) in E-Warm animals compared with both control and E-Cold. HSP10, HSP60, and HSP73 did not differ between groups. Exercise increased manganese superoxide dismutase (MnSOD) activity in both E-Warm and E-Cold hearts ( P < 0.05). Protection against I/R-induced lipid peroxidation in the LV paralleled the increase in MnSOD activity whereas lower levels of lipid peroxidation were observed in both E-Warm and E-Cold groups compared with control. We conclude that exercise-induced myocardial protection against a moderate duration I/R insult is not dependent on increases in myocardial HSPs. We postulate that exercise-associated cardioprotection may depend, in part, on increases in myocardial antioxidant defenses.


2005 ◽  
Vol 391 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Renu Wadhwa ◽  
Syuichi Takano ◽  
Kamaljit Kaur ◽  
Satoshi Aida ◽  
Tomoko Yaguchi ◽  
...  

Mortalin/mtHsp70 (mitochondrial Hsp70) and HSP60 (heat-shock protein 60) are heat-shock proteins that reside in multiple subcellular compartments, with mitochondria being the predominant one. In the present study, we demonstrate that the two proteins interact both in vivo and in vitro, and that the N-terminal region of mortalin is involved in these interactions. Suppression of HSP60 expression by shRNA (short hairpin RNA) plasmids caused the growth arrest of cancer cells similar to that obtained by suppression of mortalin expression by ribozymes. An overexpression of mortalin, but not of HSP60, extended the in vitro lifespan of normal fibroblasts (TIG-1). Taken together, this study for the first time delineates: (i) molecular interactions of HSP60 with mortalin; (ii) their co- and exclusive localizations in vivo; (iii) their involvement in tumorigenesis; and (iv) their functional distinction in pathways involved in senescence.


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