Calcium homeostasis in cardiomyocytes isolated from heat-shocked rats

1996 ◽  
Vol 271 (5) ◽  
pp. H1938-H1946 ◽  
Author(s):  
R. N. Cornelussen ◽  
L. Ver Donck ◽  
G. Verellen ◽  
M. Borgers ◽  
G. J. van der Vusse ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Simultaneous Measurement ◽  
Left Ventricular ◽  
Cellular Mechanism ◽  
Fluorescence Ratio ◽  
Adult Rats ◽  
Quiescent Cells ◽  
Contractile Performance

The cellular mechanism of heat shock-mediated cardioprotection is still under debate. Because heat pretreatment negatively affects the normoxic left ventricular contractile performance in vitro when the extracellular Ca2+ concentration ([Ca2+]o) is relatively low (0.65-1.25 mM), the intracellular Ca2+ homeostasis was studied in more detail in cardiomyocytes isolated from adult rats 24 h after heat stress (42 degrees C for 15 min) or anesthesia (control). Sensitivity to Ca2+ overload was assessed by exposure to veratridine (quiescent cells) or to [Ca2+]o ranging from 0.125 to 20 mM in quiescent and paced cardiomyocytes. The fraction of irreversibly hypercontracted cells was not different between groups. The fura-2 fluorescence ratio (I340/I380), which was used as a measure for cytoplasmic Ca2+ concentration ([Ca2+]i) in quiescent cells after exposure to [Ca2+]o (0.5-10 mM), was also not different between groups. Myofilament Ca2+ sensitivity was assessed in paced (0.5 Hz) cells by simultaneous measurement of [Ca2+]i transients and cell shortening. At stepwise increases of [Ca2+]o from 1 to 10 mM, these parameters were comparable between groups. The diastolic cell length shortened progressively and equally in both groups after increasing [Ca2+]o. However, within 2 min of return from 10 to 1 mM [Ca2+]o, cells from heat-shocked rats retained the same length, whereas cells from control rats contracted further (P = 0.05). These data suggest that heat stress improves relaxation after challenge with high [Ca2+]o.

scholarly journals Cytoprotective Effects of Taurine on Heat-Induced Bovine Mammary Epithelial Cells In Vitro

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 258
Author(s):  
Hui Bai ◽  
Tingting Li ◽  
Yan Yu ◽  
Ningcong Zhou ◽  
Huijuan Kou ◽  
...  
Keyword(s):  
T Cells ◽  
Heat Stress ◽  
Heat Shock ◽  
T Antigen ◽  
Mammary Epithelial ◽  
Epithelial Cell Line ◽  
Heat Shock Factor 1 ◽  
Alveolar Cells ◽  
Bovine Mammary Epithelial Cells

It is a widely known that heat stress induces a reduction in milk production in cows and impairs their overall health. Studies have shown that taurine protects tissues and organs under heat stress. However, there have yet to be studies showing the functions of taurine in mammary alveolar cells-large T antigen (MAC-T) (a bovine mammary epithelial cell line) cells under heat shock. Therefore, different concentrations of taurine (10 mM, 50 mM, and 100 mM) were tested to determine the effects on heat-induced MAC-T cells. The results showed that taurine protected the cells against heat-induced damage as shown by morphological observations in conjunction with suppressed the translocation and expression of heat shock factor 1 (HSF1). Moreover, taurine not only reversed the decline in antioxidase (superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX)) activities but also attenuated the accumulation of malondialdehyde (MDA). Meanwhile, mitochondrial damage (morphology and complex I activity) resulting from heat exposure was mitigated. Taurine also alleviated the rates of cell apoptosis and markedly depressed the mRNA expressions of BCL2 associated X, apoptosis regulator (BAX) and caspase3. Furthermore, compared with the heat stress (HS) group, the protein levels of caspase3 and cleaved caspase3 were decreased in all taurine groups. In summary, taurine improves the antioxidant and anti-apoptosis ability of MAC-T cells thereby alleviates damage of cells due to heat insults.

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

2021 ◽  
Author(s):  
Ragu Kanagasabai ◽  
Krishnamurthy Karthikeyan ◽  
Jay L. Zweier ◽  
Govindasamy Ilangovan
Keyword(s):  
Heart Failure ◽  
Heat Shock ◽  
Left Ventricular ◽  
Serine Phosphorylation ◽  
Apoptotic Pathway ◽  
Mtor Phosphorylation ◽  
Inner Diameter ◽  
Shock Proteins ◽  
Parp 1

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.

scholarly journals Transcriptome and translatome changes in germinated pollen under heat stress uncover roles of transporter genes involved in pollen tube growth

2020 ◽  
Author(s):  
Laetitia Poidevin ◽  
Javier Forment ◽  
Dilek Unal ◽  
Alejandro Ferrando
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
High Temperature ◽  
Heat Shock ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Heat Shock Genes ◽  
Germinated Pollen

ABSTRACTPlant reproduction is one key biological process very sensitive to heat stress and, as a consequence, enhanced global warming poses serious threats to food security worldwide. In this work we have used a high-resolution ribosome profiling technology to study how heat affects both the transcriptome and the translatome of Arabidopsis thaliana pollen germinated in vitro. Overall, a high correlation between transcriptional and translational responses to high temperature was found, but specific regulations at the translational level were also present. We show that bona fide heat shock genes are induced by high temperature indicating that in vitro germinated pollen is a suitable system to understand the molecular basis of heat responses. Concurrently heat induced significant down-regulation of key membrane transporters required for pollen tube growth, thus uncovering heat-sensitive targets. We also found that a large subset of the heat-repressed transporters is specifically up-regulated, in a coordinated manner, with canonical heat-shock genes in pollen tubes grown in vitro and semi in vivo, based on published transcriptomes from Arabidopsis thaliana. Ribosome footprints were also detected in gene sequences annotated as non-coding, highlighting the potential for novel translatable genes and translational dynamics.

Expressions of heat shock proteins under heat-stress and interferon-treatment: An in vitro study on osteosarcoma

1996 ◽  
Vol 3 (4) ◽  
pp. 233-239 ◽  
Author(s):  
Toshikazu Kubo ◽  
Yuji Tamura ◽  
Kenji Takahashi ◽  
Jiro Imanishi ◽  
Yasusuke Hirasawa
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
In Vitro Study ◽  
Vitro Study ◽  
Interferon Treatment ◽  
Shock Proteins

Chronic β-agonist administration affects cardiac function of adult but not old rats, independent of β-adrenoceptor density

2005 ◽  
Vol 289 (1) ◽  
pp. H344-H349 ◽  
Author(s):  
Paul Gregorevic ◽  
James G. Ryall ◽  
David R. Plant ◽  
Martin N. Sillence ◽  
Gordon S. Lynch
Keyword(s):  
Cardiac Function ◽  
Contractile Function ◽  
Heart Function ◽  
Relative Increase ◽  
Left Ventricular ◽  
Aged Rats ◽  
Adult Rats ◽  
Age Related ◽  
Heart Mass

Although β-adrenoceptor agonists have clinical merit for attenuating the age-related loss of skeletal muscle mass and strength (sarcopenia), potential cardiac-related side effects may limit their clinical application. The aim of this study was to determine whether chronic β-agonist administration impairs cardiac function in adult or aged rats. Adult (16 mo) and aged (28 mo) Fischer 344 rats were treated with fenoterol (1.4 mg·kg−1·day−1 ip) or vehicle for 4 wk. Heart function was assessed in vitro before analyses of cardiac structure and β-adrenoceptor density. Heart mass increased 17% and 25% in fenoterol-treated adult and aged rats, respectively. The increased heart mass in aged, but not adult, rats was associated with a relative increase in collagen content. Cardiac hypertrophy in adult rats was associated with an increase in left ventricular developed pressure, a marked reduction in cardiac output, and a reduction in coronary flow per unit heart mass. In contrast, negligible differences in ventricular function were observed in fenoterol-treated aged rats. The differential effect on contractile function was not associated with age-related differences in β-adrenoceptor density but, rather, an age-related increase in downregulation after treatment. Our results show that chronic β-agonist treatment impairs cardiac function to a greater extent in adult than in aged rats. These results provide important information regarding the potential effects of chronic β-agonist use on cardiac function and the future development of safe and effective treatments for sarcopenia.

scholarly journals Localization and expression of heat shock protein 70 with rat myocardial cell damage induced by heat stress in vitro and in vivo

2014 ◽  
Vol 11 (3) ◽  
pp. 2276-2284 ◽  
Author(s):  
HONGBO CHEN ◽  
ABDELNASIR ADAM ◽  
YANFEN CHENG ◽  
SHU TANG ◽  
JÖRG HARTUNG ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Cell Damage ◽  
Myocardial Cell ◽  
Myocardial Cell Damage

Exposure of neonatal rats to carbon monoxide alters cardiac adaptation to aortic constriction

1991 ◽  
Vol 70 (6) ◽  
pp. 2697-2702 ◽  
Author(s):  
M. O. Boluyt ◽  
D. G. Penney ◽  
F. J. Clubb ◽  
T. P. White
Keyword(s):  
Carbon Monoxide ◽  
Adaptive Response ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Control Group ◽  
Neonatal Rats ◽  
Aortic Constriction ◽  
Adult Rats ◽  
Control Value

We tested the hypothesis that a 32-day exposure of newborn rats to 500 ppm carbon monoxide (CO) would alter the adaptive response of the heart to aortic constriction in adulthood. At 110 days of age aortic constriction or sham operations were performed, and hearts were studied 28 days later. Aortic constriction increased left ventricular (LV) mass by 40% over the control value of 611 +/- 27 mg; this adaptive response was not altered by CO exposure. Aortic constriction and CO exposure increased right ventricular (RV) mass by 10 and 11%, respectively, over the control value of 185 +/- 10 mg. The effects of both experimental procedures on RV mass were additive (23%). Peak LV pressure development (dP/dtmax) in vitro increased 29% after aortic constriction in the nonexposed rats. CO exposure blunted the increase in peak LV systolic pressure due to aortic constriction. Maximum positive and negative dP/dtmax decreased by 19% after aortic constriction and were unaffected by CO exposure. The percentage of alpha-myosin heavy chain (MHC) in the ventricles was 94 +/- 2% in the control group and was decreased to 81 +/- 3% by aortic constriction. In contrast, the percentage of alpha-MHC was 87 +/- 2% for CO-exposed rats and was not significantly altered after aortic constriction. In vitro coronary flow was increased 18% in hearts of adult rats exposed to CO as neonates. Exposure of neonatal rats to CO induced chronic adaptations in the myocardium, some of which became evident in adulthood only when hearts were challenged by aortic constriction.

The Heat-Shock Response and Expression of Heat-Shock Proteins in Wheat Under Diurnal Heat Stress and Field Conditions

1994 ◽  
Vol 21 (6) ◽  
pp. 857 ◽  
Author(s):  
HT Nguyen ◽  
CP Joshi ◽  
N Klueva ◽  
J Weng ◽  
KL Hendershot ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Tolerance ◽  
Heat Shock Response ◽  
Field Conditions ◽  
Shock Response ◽  
Heat Tolerant ◽  
Shock Proteins

The occurrence of heat-shock proteins (HSPs) in response to high temperature stress is a universal phenomenon in higher plants and has been well documented. However, in agriculturally important species, less is known about the expression of HSPs under natural environments. A review of the heat-shock response in wheat (Triticum aestivum L.) is presented and recent results on the expression of wheat HSPs under diurnal stress and field conditions are reported. In the field experiment, flag leaf blade temperatures were obtained and leaf blades collected for northern blot analysis using HSP 16.9 cDNA as a probe. Temperatures of leaf blades ranged from 32 to 35�C under the tested field conditions at New Deal near Lubbock, Texas. Messenger RNAs encoding a major class of low molecular weight HSPs, HSP 16.9, were detected in all wheat genotypes examined. The results suggested that HSPs are synthesised in response to heat stress under agricultural production, and furthermore, that HSPs are produced in wheats differing in geographic background. In the controlled growth chamber experiment, HSP expression in two wheat cultivars, Mustang (heat tolerant) and Sturdy (heat susceptible) were analysed to determine if wheat genotypes differing in heat tolerance differ in in vitro HSP synthesis (translatable HSP mRNAs) under a chronic, diurnal heat-stress regime. Leaf tissues were collected from seedlings over a time-course and poly (A)+RNAs were isolated for in vitro translation and 2-D gel electrophoresis. The protein profiles shown in the 2-D gel analysis revealed that there were not only quantitative differences of individual HSPs between these two wheat lines, but also some unique HSPs which were only found in the heat tolerant line. This data provides evidence of a correlation between HSP synthesis and heat tolerance in wheat under a simulated field environment and suggests that further genetic analysis of HSPs in a segregating population is worthy of investigation. In conclusion, the results of this study provide an impetus for the investigation of the roles of HSP genes in heat tolerance in wheat.

Sign in / Sign up

Export Citation Format

Share Document