The association of Hsp90 expression induced by aspirin with anti-stress damage in chicken myocardial cells

HSP90 Enhances Mitophagy to Improve the Resistance of Car-Diomyocytes to Heat Stress in Wenchang Chickens

Heat shock protein 90 (HSP90) is recognized for its protective effects against heat stress damage; however, the specific functions and underlying molecular mechanisms of HSP90 in heat-stressed cardiomyocytes remain largely unexplored, particularly in tropical species. In our study, Wenchang chickens (WCCs) were classified into two groups: the heat stress survival (HSS) group and the heat stress death (HSD) group, based on their survival following exposure to heat stress. Heat stress resulted in significant cardiomyocyte damage, mitochondrial dysfunction, and apoptosis in the HSD group, while the damage was less pronounced in the HSS group. We further validated these findings in primary cardiomyocytes derived from Wenchang chickens (PCWs). Additionally, heat stress was found to upregulate Pink1/Parkin-mediated mitophagy, which was accompanied by an increase in HSP90 expression in both cardiomyocytes and PCWs. Our results demonstrated that HSP90 overexpression enhances PINK1/Parkin-mediated mitophagy, ultimately inhibiting apoptosis and oxidative stress in heat-stressed PCWs. However, the application of Geldanamycin (GA) reversed these effects. Notably, we discovered that HSP90 interacts with Beclin-1 through mitochondrial translocation and directly regulates mitophagy levels in PCWs. In summary, we have elucidated a novel role for HSP90 and mitophagy in regulating heat stress-induced acute cardiomyocyte injury.

Hsp90 protected chicken primary myocardial cells from heat-stress injury by inhibiting oxidative stress and calcium overload in mitochondria

Severe heat stress can cause human and animal heart failure and sudden death, which is an important issue of public health worldwide. Our previous studies in animals showed that myocardial cells injury was critical in the above process, and Hsp90 induction has a definite anti-myocardial injury effect, especially through aspirin (ASA). But the mechanism has not been fully clarified. In this study, an in vitro heat stress model of chicken primary myocardial cells (CPMCs) most sensitive to heat stress was used to explore the cell injuries and corresponding molecular resistance mechanism. We found that heat stress resulted in serious oxidation stress and calcium overload in mitochondria, which destroyed the mitochondrial structure and function and then triggered the cell death mechanism of CPMCs. Hsp90 was proven to be a central regulator for resisting heat-stress injury in CPMCs mitochondria using its inhibitor and inducer (geldanamycin and ASA), respectively. The mechanism involved that Hsp90 could activate Akt and PKM2 signals to promote Bcl-2 translocation into mitochondria and its phosphorylation, thereby preventing ROS production and subsequent cell apoptosis. In addition, Hsp90 inhibited mitochondrial calcium overload to overcome MPTP opening and MMP suppression through the inhibitory effect of Raf-1-ERK activation on the CREB-IP3R pathway. This study is the first to reveal a pivotal reason for heat-stressed damage in chicken myocardial cells at subcellular level and identify an effective regulator, Hsp90, and its protective mechanisms responsible for maintaining mitochondrial homeostasis.

Gender differences in GRK2 in cardiovascular diseases and its interactions with estrogen

G protein-coupled receptor kinase 2 (GRK2) is a multifunctional protein involved in regulating G protein-coupled receptor (GPCR) and non-GPCR signaling in the body. In the cardiovascular system, increased expression of GRK2 has been implicated in the occurrence and development of several cardiovascular diseases (CVDs). Recent studies have found gender differences in GRK2 in the cardiovascular system under physiological and pathological conditions, where GRK2's expression and activity are increased in males than in females. The incidence of CVDs in premenopausal women is lower than in men of the same age, which is related to estrogen levels. Given the shared location of GRK2 and estrogen receptors, estrogen may interact with GRK2 by modulating vital molecules such as calmodulin (CaM), caveolin, RhoA, nitrate oxide (NO), and mouse double minute 2 homolog (Mdm2), via signaling pathways mediated by estrogen's genomic (ERα and ERβ), and non-genomic (GPER) receptors, conferring cardiovascular protection in females. Highlighting the gender differences in GRK2 and understanding its interaction with estrogen in the cardiovascular system is pertinent in treating gender-related CVDs. As a result, this article explores the gender differences of GRK2 in the cardiovascular system and its relationship with estrogen during disease conditions. Estrogen's protective and therapeutic effects and its mechanism on GRK2-related cardiovascular diseases have also been discussed.

HSF1 and GM-CSF expression, its association with cardiac health, and assessment of organ function during heat stress in crossbred Jersey cattle

The study aimed to evaluate the differential expression of HSF1 and GM-CSF mRNA in PBMCs and correlate it with myocardial injury in crossbred Jersey heifers during heat stress. The study also assessed the effect of heat stress on cardiac electrical activity, vascular health, liver function and kidney function. The experiment was conducted in two phases: for heat stressed animals; HS in June (THI ranged from 80.0 to 89.8) and for control group i.e. not exposed to heat stress in January (THI ranged between 70.1 and 71.4). Results of the study revealed that the relative abundance of HSF1 and GM-CSF mRNA increased significantly (P < 0.05) in HS. Serum cardiac biomarkers such as CK-MB, AST and CRP were significantly elevated (P < 0.05) in HS. cTnI was detected 'positive' in nineteen out of twenty four cases in HS. Correlation of HSF1 and GM-CSF expression with concentration of LDH, CKMB, CRP and AST in HS was negative but non-significant (P > 0.05). Significant (P < 0.05) ECG findings in HS were increased heart rate, decreased RR interval, decreased PR interval, decreased QRS amplitude and decreased amplitude of P wave. Marked reduction (P < 0.05) in serum cholesterol and triglyceride levels was observed in HS. ALP, AST, bilirubin and urea levels in serum were significantly elevated (P < 0.05) in HS. In conclusion, cardiac enzymes in serum were significantly elevated in HS indicating myocardial injury. HSF1 and GM-CSF mRNA expression alone was inadequate in conferring cytoprotection to cardiac cells in HS. Cardiac electrical activity, vascular status, liver and kidney function were significantly altered in HS.

Thermoregulatory responses in riverine buffaloes against heat stress: An updated review

High heat and humidity stress have been a perpetual perilous for the buffalo's production and productivity in tropics and subtropics including India. Productive potential of livestock's species including buffaloes is maximum with in thermo-neutral zone (TNZ) and if ambient temperature exceeds TNZ and upper critical temperature expose livestock's to heat stress conditions. For decades, heat stress has been the prime factor to plummet buffalo's growth, development, reproduction and production in tropics and subtropics including India. In general, buffaloes are homeotherms and known as temperature regulators as they resist the variations in ambient temperatures. Generally, buffaloes like other livestock's display amalgamation of thermoregulatory responses to withstand the changes occurred in their micro and macro environment. These thermoregulatory responses are behavioural, physiological, neuro-endocrine and molecular responses acting synergistically to counteract the deleterious effects of heat stress. Amidst all responses, molecular responses play major role to confer thermo-tolerance through expression of highly conserved family of proteins known as heat shock proteins (HSPs). Despite of these thermoregulatory responses, heat stress prodigiously muddles buffalo's production and productivity. The present review highlights the thermoregulatory responses manifested by riverine buffaloes against heat stress.

Gingko biloba extract EGB761 alleviates heat-stress damage in chicken heart tissue by stimulating Hsp70 expression in vivo in vascular endothelial cells

1. This study aimed to investigate the protective effects of Gingko biloba extract EGB761 on heat-stressed chicken heart in vivo and its underlying relevance to Hsp70.2. A total of 50 one-day-old female chicks were randomly divided into five groups: control (Con), heat-stress (HS), 0.1% EGB761 plus heat-stress (0.1%EGB+HS), 0.3%EGB761 plus heat-stress (0.3%EGB+HS) and 0.6%EGB761 plus heat-stress (0.6%EGB+HS) groups. After administration of EGB761 for 45 days, the chickens in each group were exposed to a single heat-stress event at 38 ± 1°C for 3 h.3. EGB761 attenuated the abnormal symptoms and pathological scores of myocardium of heat-stressed chickens. Despite a reduction in the transcription and translation of the Hsp70 gene in heat-stressed myocardium, EGB761 induced the expression of Hsp70 in endothelial cells of the microarteries and venules into the blood, and reduced heat-stress damage in vascular endothelial cells.4. Supplementation with EGB761 before heat-stress exposure protected chicken myocardium from damage by increasing serum Hsp70 protein from myocardial cells and cardiac microvascular endothelial cells and protected the microvascular system from adverse injury.

Heat shock protein 90 relieves heat stress damage of myocardial cells by regulating Akt and PKM2 signaling in vivo

Heat shock protein 90 (Hsp90) is associated with resisting heat-stress injury to the heart, particularly in myocardial mitochondria. However, the mechanism underlying this effect remains unclear. The present study was based on the high expression of Hsp90 during heat stress (HS) and involved inducing higher expression of Hsp90 using aspirin in mouse hearts. Higher Hsp90 levels inhibited HS-induced myocardial damage and apoptosis, and mitochondrial dysfunction, by stimulating Akt (protein kinase B) activation and PKM2 (pyruvate kinase M2) signaling, and subsequently increasing mitochondrial Bcl-2 (B-cell lymphoma 2) levels and its phosphorylation. Functional inhibition of Hsp90 using geldanamycin verified that reducing the association of Hsp90 with Akt and PKM2 caused the functional decline of phosphorylated (p)-Akt and PKM2 that initiate Bcl-2 to move into mitochondria, where it is phosphorylated. Protection by Hsp90 was weakened by blocking Akt activation using Triciribine, which could not be recovered by normal initiation of the PKM2 pathway. Furthermore, increased Hsp70 levels induced by Akt activation in myocardial cells may flow into the blood to resist heat stress. The results provided in vivo mechanistic evidence that in myocardial cells, Hsp90 resists heat stress via separate activation of the Akt-Bcl-2 and PKM2-Bcl-2 signaling pathways, which contribute toward preserving cardiac function and mitochondrial homeostasis.

Aspirin Enhances the Protection of Hsp90 from Heat-Stressed Injury in Cardiac Microvascular Endothelial Cells Through PI3K-Akt and PKM2 Pathways

Heat stress (HS) often causes sudden death of humans and animals due to heart failure, mainly resulting from the contraction of cardiac microvasculature followed by myocardial ischemia. Cardiac microvascular endothelial cells (CMVECs) play an important role in maintaining vasodilatation. Aspirin (ASA) is well known for its protective abilities of febrile animals. However, there is little knowledge about molecular resistance mechanisms of CMVECs and which role ASA may play in this context. Therefore, we used a heat stress model of rat cardiac microvascular endothelial cell cultures in vitro and investigated the cell injuries and molecular resistance mechanism of CMVECs caused by heat stress, and the effect of aspirin (ASA) on it. HS induced severe pathological damage of CMVECs and cellular oxidative stress and dysfunction of NO release. Hsp90 was proven to be indispensable for resisting HS-injury of CMVECs through PI3K-Akt and PKM2 signaling pathways. Meanwhile, PKM2 functioned in reducing Akt phosphorylation. ASA treatment of CMVECs induced a significant expression of Hsp90, which promoted both Akt and PKM2 signals, which are beneficial for relieving HS damage and maintaining the function of CMVECs. Akt activation also promoted HSF-1 that regulates the expression of Hsp70, which is known to assist Hsp90′s molecular chaperone function and when released to the extracellular liquid to protect myocardial cells from HS damage. To the best of our knowledge, this is the first study to show that HS damages CMVECs and the protection mechanism of Hsp90 on it, and that ASA provides a new potential strategy for regulating cardiac microcirculation preventing HS-induced heart failure.

Impact of heat stress on transcriptional abundance of HSP70 in cardiac cells of goat

The present study was aimed to document the effect of heat stress on the transcriptional abundance of heat shock protein 70 (HSP70) mRNA in cultured cardiac cells of goat. The heart tissues (n = 6) from different goats were used for the culture study. The cardiac cells obtained from different heart tissues were cultured in 24 well cell culture plates and incubated in a humidified CO₂ (5%) incubator at 37 °C. The cardiac cells were allowed to become 75-80% confluent after 72 h of incubation. Thereafter, the cardiac cells were subjected to heat exposure at 42 °C (heat exposed) for 0, 20, 60 and 100 min. The cardiac cells exposed to heat stress at 42 °C for 0 min was taken as control. The relative abundance of HSP70 mRNA was gradually up-regulated (p < .05) from 20 to 100 min of heat exposure and reached the zenith (p < .05) at 100 min of heat challenge. The present finding highlights that, HSP70 could possibly act as a cytoprotective factor and may promote cardiac cell survival against the detrimental effect of heat stress. Moreover, this study may serve as the harbinger to conduct further research work on expression kinetics of HSP70 in cardiac cells of goat including other livestock species.

Co-enzyme Q10 protects chicken hearts from in vivo heat stress via inducing HSF1 binding activity and Hsp70 expression

In this report, we investigated the protective function of co-enzyme Q10 on chicken hearts during in vivo heat stress (HS) and the relationship with Hsp70 expression. The concentration of co-enzyme Q10 (Q10) in the serum indicated that Q10 exogenously added prior HS was fully absorbed by chickens and is maintained at high levels during HS. The level of heart and oxidative damage-associated enzymes in the serum revealed that treatment with Q10 decreased the activity of CK-MB, CK, and LDH compared with the HS group; moreover, oxidative injury was also alleviated by Q10 according to the level of SOD, MDA, and T-AOC in the serum compared with HS group during heat stress. A pathological examination indicated that the chicken hearts suffered serious damage during HS, including hemorrhage, granular changes, karyopyknosis, and cardiac muscle fiber disorder; however, the extent of heart damage was reduced in HS + Q10 group. Our results indicated that the addition of Q10 could upregulate the expression of Hsp70 during HS compared with the HS group. Compared with the HS group, the addition of Q10 significantly increased the gene expression of hsf1 during HS and hsf3 at 5 h of HS. The expression of hsf2 and hsf4 was not influenced by HS. Q10 could only accelerate the trimerization of HSF1 as well binding activities to Hsp70 HSE according to native page and ChIP assays. These findings suggest that co-enzyme Q10 can protect chicken hearts from in vivo HS by inducing HSF1 binding activity and Hsp70 expression.

Hsp70 expression induced by Co-Enzyme Q10 protected chicken myocardial cells from damage and apoptosis under in vitro heat stress

The aim of this study was to investigate whether induction of Hsp70 expression by co-enzyme Q10 (Q10) treatment protects chicken primary myocardial cells (CPMCs) from damage and apoptosis in response to heat stress for 5 hours. Analysis of the expression and distribution of Hsp70 and the levels of the damage-related enzymes creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH), as well as pathological analysis showed that co-enzyme Q10 alleviated the damage caused to CPMCs during heat stress. Further, analysis of cell apoptosis and the expression of cleaved caspase-3 indicated that co-enzyme Q10 did have an anti-apoptotic role during heat stress. Western blot analysis showed that pretreatment with co-enzyme Q10 led to a significant increase in the expression of Hsp70 during heat stress. Immunostaining assays confirmed the results of western blot analysis and also showed that co-enzyme Q10 could accelerate the translocation of Hsp70 into the nucleus during heat stress, but this was not observed in the group that was treated with only co-enzyme Q10. These findings seem to indicate that co-enzyme Q10 protected CPMCs from heat stress via the induction of Hsp70. To investigate this, 200 μM quercetin, an Hsp70 inhibitor, was used to inhibit the expression of Hsp70 2 h before heat stress. Quercetin pre-treatment was observed to suppress the expression of Hsp70 as well the protective function of co-enzyme Q10 at 5 h of heat stress. This finding confirms that Q10 brought about its effects via Hsp70 expression, but the mechanism underlying this needs further investigation.

Co-enzyme Q10 and acetyl salicylic acid enhance Hsp70 expression in primary chicken myocardial cells to protect the cells during heat stress

We investigated the effects of co-enzyme Q10 (Q10) and acetyl salicylic acid (ASA) on expression of Hsp70 in the protection of primary chicken myocardial cells during heat stress. Western blot analysis showed that Q10 and ASA accelerated the induction of Hsp70 when chicken myocardial cells were exposed to hyperthermia. In the absence of heat stress, however, neither Q10 nor ASA are able to upregulate Hsp70 expression. Analysis of enzymes that respond to cellular damage and pathological examination revealed that ectopic expression of ASA and Q10 alleviate cellular damage during heat stress. Quantification of heat shock factors (HSF) indicated that treatment of ASA increased the expression of HSF-1 and HSF-3 during heat stress. Treatment with Q10 resulted in the elevation of HSF-1 expression. Expression of HSF-2 and HSF-4 was not affected by ASA or Q10. Subcellular distribution analysis of HSF-1 and HSF-3 showed that in response to heat stress ASA promoted nuclear translocation of HSF-1 and HSF-3, while Q10 promoted only HSF-1 nuclear translocation. Chromatin immunoprecipitation (ChIP) analysis indicated that HSF-1 occupies the Hsp70 promoter in chicken primary myocardial cells during heat stress and under normal conditions, while HSF-3 occupies the Hsp70 promoter only during heat stress. Real-time PCR analysis revealed that ASA induces HSF-1 and HSF-3 binding to Hsp70 HSE, while Q10 only induces HSF1 binding to Hsp70 HSE, in agreement with the impact of HSF1 and HSF3 silencing on Hsp70 expression. These data demonstrate that ASA and Q10 both induce the expression of Hsp70 to protect chicken primary myocardial cells during heat stress, but through distinct pathways.