Heat shock protein 70 acts as a potential biomarker for early diagnosis of heart failure

Hsp70: A Multifunctional Chaperone in Maintaining Proteostasis and Its Implications in Human Disease

Hsp70, a 70 kDa molecular chaperone, plays a crucial role in maintaining protein homeostasis. It interacts with the DnaJ family of co-chaperones to modulate the functions of client proteins involved in various cellular processes, including transmembrane transport, extracellular vesicle trafficking, complex formation, and proteasomal degradation. Its presence in multiple cellular organelles enables it to mediate stress responses, apoptosis, and inflammation, highlighting its significance in disease progression. Initially recognized for its essential roles in protein folding, disaggregation, and degradation, later studies have demonstrated its involvement in several human diseases. Notably, Hsp70 is upregulated in multiple cancers, where it promotes tumor proliferation and serves as a tumor immunogen. Additionally, epichaperome networks stabilize protein-protein interactions in large and long-lived assemblies, contributing to both cancer progression and neurodegeneration. However, extracellular Hsp70 (eHsp70) in the tumor microenvironment can activate immune cells, such as natural killer (NK) cells, suggesting its potential in immunotherapeutic interventions, including CAR T-cell therapy. Given its multifaceted roles in cellular physiology and pathology, Hsp70 holds immense potential as both a biomarker and a therapeutic target across multiple human diseases. This review highlights the structural and functional importance of Hsp70, explores its role in disease pathogenesis, and discusses its potential in diagnostic and therapeutic applications.

Protective Effects of Oxyresveratrol in IsoproterenolInduced Myocardial Infarction in Rats: A Stereological Study

The aim of this study is to examine the protective effect of oxyresveratrol (OXY) against isoproterenol-induced myocardial infarction in rats, through routine biochemical parameters and oxidative stress parameters that show heart damage. Oxyresveratrol was administered by oral gavage at doses of 10 and 20 mg/kg, respectively, once a day for 5 days. On the fourth and fifth days, 180 mg/kg isoproterenol was administered intraperitoneally to the OXY treatment group and control groups. Twenty-four hours after the last isoproterenol application, blood and heart tissue were taken under anesthesia and transferred to -80 degrees and formalin for biochemical and histopathological studies. CK-MB and TnI levels were measured in serum obtained from blood. In the heart tissue, antioxidant parameters, superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA) levels, and histopathological and stereological evaluations were performed. Oxyresveratrol has antioxidant and anti-inflammatory activity depending on the dose. Oxyresveratrol showed potent protective effect against isoproterenol-induced myocardial infarction. It has been proven that at all doses of oxyresveratrol, statistically, isoproterenol decreased the MDA level, which was one of the oxidative stress markers, compared to the control group, and increased SOD activity and GSH levels. Similar to the biochemically determined parameters, oxyresveratrol treatment was also found to have a protective effect at the cell level, histopathologically and stereologically. All results show that oxyresveratrol has strong antioxidant and anti-inflammatory activity, especially at a dose of 20 mg/kg, it significantly reduces myocardial damage and this agent has a cardioprotective effect.

Heat Shock Protein 70 Constitutes a Promising Novel Biomarker in Differential Diagnosis between Takotsubo Syndrome and Non-ST-Segment Elevation Myocardial Infarction

(1) Background: Due to similar clinical presentation and a lack of specific biomarkers, initial differentiation between Takotsubo syndrome (TTS) and non-ST-segment elevation myocardial infarction (NSTEMI) remains challenging in daily practice. Heat Shock Protein 70 (HSP70) is a novel biomarker that is recognized for its potential in the diagnosis and differentiation of cardiovascular conditions. (2) Methods: Data from a total of 156 patients were analyzed (32.1% NSTEMI, 32.7% TTS, and 35.3% controls). Serum concentrations of HSP70 were determined using ELISA and compared between patients and controls. ROC curve analysis, logistic regression analysis and propensity-score-weighted logistic regression were conducted. (3) Results: Concentrations of HSP70 were highest in patients with TTS (median 1727 pg/mL vs. ACS: median 1545 pg/mL vs. controls: median 583 pg/mL, p < 0.0001). HSP70 was predictive for TTS in binary logistic regression analysis (B(SE) = 0.634(0.22), p = 0.004), which even remained significant after correction for possible confounders in propensity-score-weighted analysis. ROC curve analysis also revealed a significant association of HSP70 with TTS (AUC: 0.633, p = 0.008). (4) Conclusions: Based on our findings, HSP70 constitutes a promising biomarker for discrimination between TTS and NSTEMI, especially in combination with established cardiovascular biomarkers like pBNP or high-sensitivity cardiac troponin.

The Role of Extracellular Heat Shock Proteins in Cardiovascular Diseases

In the early 1960s, heat shock proteins (HSPs) were first identified as vital intracellular proteinaceous components that help in stress physiology and reprogram the cellular responses to enable the organism's survival. By the early 1990s, HSPs were detected in extracellular spaces and found to activate gamma-delta T-lymphocytes. Subsequent investigations identified their association with varied disease conditions, including autoimmune disorders, diabetes, cancer, hepatic, pancreatic, and renal disorders, and cachexia. In cardiology, extracellular HSPs play a definite, but still unclear, role in atherosclerosis, acute coronary syndromes, and heart failure. The possibility of HSP-targeted novel molecular therapeutics has generated much interest and hope in recent years. In this review, we discuss the role of Extracellular Heat Shock Proteins (Ec-HSPs) in various disease states, with a particular focus on cardiovascular diseases.

Heat shock proteins: Biological functions, pathological roles, and therapeutic opportunities

The heat shock proteins (HSPs) are ubiquitous and conserved protein families in both prokaryotic and eukaryotic organisms, and they maintain cellular proteostasis and protect cells from stresses. HSP protein families are classified based on their molecular weights, mainly including large HSPs, HSP90, HSP70, HSP60, HSP40, and small HSPs. They function as molecular chaperons in cells and work as an integrated network, participating in the folding of newly synthesized polypeptides, refolding metastable proteins, protein complex assembly, dissociating protein aggregate dissociation, and the degradation of misfolded proteins. In addition to their chaperone functions, they also play important roles in cell signaling transduction, cell cycle, and apoptosis regulation. Therefore, malfunction of HSPs is related with many diseases, including cancers, neurodegeneration, and other diseases. In this review, we describe the current understandings about the molecular mechanisms of the major HSP families including HSP90/HSP70/HSP60/HSP110 and small HSPs, how the HSPs keep the protein proteostasis and response to stresses, and we also discuss their roles in diseases and the recent exploration of HSP related therapy and diagnosis to modulate diseases. These research advances offer new prospects of HSPs as potential targets for therapeutic intervention.

Angiotensin II Exaggerates SARS-CoV-2 Specific T-Cell Response in Convalescent Individuals following COVID-19

Dysregulation of renin−angiotensin systems during coronavirus disease 2019 (COVID-19) infection worsens the symptoms and contributes to COVID-19 severity and mortality. This study sought to investigate the effect of exogenous angiotensin II (Ang-II) on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T-cells response in recovered COVID-19 patients. Human peripheral blood mononuclear cells (PBMCs) were treated with Ang II and then stimulated with a SARS-CoV-2 peptide pool. T-cell responses were measured using flow cytometry, while enzyme-linked immunosorbent assay (ELISA) and intracellular cytokine staining (ICS) assays determined functional capability and polarization. Additionally, the relative level of protein phosphorylation was measured using a phosphokinase array. Our results showed that Ang II treatment significantly increased the magnitude of SARS-CoV-2-specific T-cell response in stimulated PBMCs with a SARS-CoV-2 peptide pool. Moreover, the phosphorylation levels of numerous proteins implicated in cardiovascular diseases, inflammation, and viral infection showed significant increases in the presence of Ang II. The mitogenic stimulation of PBMCs after Ang II and SARS-CoV-2 peptide pool stimulation showed functional polarization of T-cells toward Th1/Th17 and Th17 phenotypes, respectively. Meanwhile, ELISA showed increased productions of IL-1β and IL-6 in Ang II-stimulated PBMCs without affecting the IL-10 level. To our knowledge, this study is the first to demonstrate that Ang II exaggerates SARS-CoV-2-specific T-cells response. Therefore, during COVID-19 infection, Ang II may aggravate the inflammatory response and change the immune response toward a more inflammatory profile against SARS-CoV-2 infection.

Acute Changes in Myocardial Expression of Heat Shock Proteins and Apoptotic Response Following Blood, delNido, or Custodiol Cardioplegia in Infants Undergoing Open-Heart Surgery

Stress caused by cardioplegic ischemic arrest was shown to alter the expression levels of heat shock proteins (Hsp), but little is known about their effects, particularly on pediatric hearts. This study aimed to investigate whether myocardial cellular stress and apoptotic response changes due to different cardioplegia (CP) solutions during cardiopulmonary bypass (CPB) in infants and to determine their influence on surgical/clinical outcomes. Therefore, twenty-seven infants for surgical closure of ventricular septal defect were randomly assigned to a CP solution: normothermic blood (BCP), delNido (dNCP), and Custodiol (CCP). Hsp levels and apoptosis were determined by immunoblotting in cardiac tissue from the right atrium before and after CP, and their correlations with cardiac parameters were evaluated. No significant change was observed in Hsp27 levels. Hsp60, Hsp70, and Hsp90 levels decreased significantly in the BCP-group but increased markedly in the CCP-group. Decreased Hsp60 and increased Hsp70 expression were detected in dNCP-group. Importantly, apoptosis was not observed in dNCP- and CCP-groups, whereas marked increases in cleaved caspase-3 and -8 were determined after BCP. Serum cardiac troponin-I (cTn-I), myocardial injury marker, was markedly lower in the BCP- and dNCP-groups than CCP. Additionally, Hsp60, Hsp70, and Hsp90 levels were positively correlated with aortic cross-clamp time, total perfusion time, and cTn-I release. Our findings show that dNCP provides the most effective myocardial preservation in pediatric open-heart surgery and indicate that an increase in Hsp70 expression may be associated with a cardioprotective effect, while an increase in Hsp60 and Hsp90 levels may be an indicator of myocardial damage during CPB.

Traditional Chinese Medicine Targeting Heat Shock Proteins as Therapeutic Strategy for Heart Failure

Heart failure (HF) is the terminal stage of multifarious heart diseases and is responsible for high hospitalization rates and mortality. Pathophysiological mechanisms of HF include cardiac hypertrophy, remodeling and fibrosis resulting from cell death, inflammation and oxidative stress. Heat shock proteins (HSPs) can ameliorate folding of proteins, maintain protein structure and stability upon stress, protect the heart from cardiac dysfunction and ameliorate apoptosis. Traditional Chinese medicine (TCM) regulates expression of HSPs and has beneficial therapeutic effect in HF. In this review, we summarized the function of HSPs in HF and the role of TCM in regulating expression of HSPs. Studying the regulation of HSPs by TCM will provide novel ideas for the study of the mechanism and treatment of HF.

Plasma obtained following murine hindlimb ischemic conditioning protects against oxidative stress in zebrafish models through activation of nrf2a and downregulation of duox

Ischemia/reperfusion of organ systems in trauma patients with resuscitated hemorrhagic shock (HSR) contributes to tissue injury and organ dysfunction. Previous studies using a murine model of HSR showed that remote ischemic preconditioning (RIC) protected against organ injury and that the plasma was able to prevent neutrophil migration in a zebrafish tailfin-cut inflammation model. In this study, we hypothesized that RIC plasma inhibits neutrophil function through a decrease in reactive oxygen species (ROS) production via the upregulation of the transcription factor Nrf2 and downstream antioxidative genes. Plasma from mice subjected to RIC (4 cycles of 5-min hindlimb ischemia/reperfusion) was microinjected into zebrafish. The results show that RIC plasma caused a reduction of ROS generation in response to tail injury. In addition, RIC plasma protected the fish larvae in the survival studies when exposed to either H2O2 or LPS. Oxidative stress PCR Array showed that RIC plasma treatment led to upregulation of antioxidative related genes including hsp70, hmox1a, nqo1 as well as downregulation of duox, the producer of H2O2. To explore the role of nrf2 in RIC, RIC plasma from Nrf2 KO mice were injected to the zebrafish and showed no inhibitory effect on neutrophil migration. Moreover, knockdown of nrf2a attenuated the anti-inflammatory and protective effect of RIC plasma. The downregulation of duox and upregulation of hmox1a were confirmed to require the activation of nrf2a. Therefore, we show that the protective effect of RIC may be related to the elaboration of humoral factors which counter injury-induced ROS generation in a nrf2-dependent fashion.

Heat Shock Proteins in Urine as Cancer Biomarkers

Heat shock proteins (HSPs) are a large family of molecular chaperones, which have shown to be implicated in various hallmarks of cancer such as resistance to apoptosis, invasion, angiogenesis, induction of immune tolerance, and metastasis. Several studies reported aberrant expression of HSPs in liquid biopsies of cancer patients and this has opened new perspectives on the use of HSPs as biomarkers of cancer. However, no specific diagnostic, predictive, or prognostic HSP chaperone-based urine biomarker has been yet discovered. On the other hand, divergent expression of HSPs has also been observed in other pathologies, including neurodegenerative and cardiovascular diseases, suggesting that new approaches should be employed for the discovery of cancer-specific HSP biomarkers. In this study, we propose a new strategy in identifying cancer-specific HSP-based biomarkers, where HSP networks in urine can be used to predict cancer. By analyzing HSPs present in urine, we could predict cancer with approximately 90% precision by machine learning approach. We aim to show that coupling the machine learning approach and the understanding of how HSPs operate, including their functional cycles, collaboration with and within networks, is effective in defining patients with cancer, which may provide the basis for future discoveries of novel HSP-based biomarkers of cancer.

Cardiac Thyrotropin-releasing Hormone Inhibition Improves Ventricular Function and Reduces Hypertrophy and Fibrosis After Myocardial Infarction in Rats

BACKGROUND

Cardiac thyrotropin-releasing hormone (TRH) is a tripeptide with still unknown functions. We demonstrated that the left ventricle (LV) TRH system is hyperactivated in spontaneously hypertensive rats and its inhibition prevented cardiac hypertrophy and fibrosis. Therefore, we evaluated whether in vivo cardiac TRH inhibition could improve myocardial function and attenuate ventricular remodeling in a rat model of myocardial infarction (MI).

METHODS AND RESULTS

In Wistar rats, MI was induced by a permanent left anterior descending coronary artery ligation. A coronary injection of a specific small interfering RNA against TRH was applied simultaneously. The control group received a scrambled small interfering RNA. Cardiac remodeling variables were evaluated one week later. In MI rats, TRH inhibition decreased LV end-diastolic (1.049 ± 0.102 mL vs 1.339 ± 0.102 mL, P < .05), and end-systolic volumes (0.282 ± 0.043 mL vs 0.515 ± 0.037 mL, P < .001), and increased LV ejection fraction (71.89 ± 2.80% vs 65.69 ± 2.85%, P < .05). Although both MI groups presented similar infarct size, small interfering RNA against TRH treatment attenuated the cardiac hypertrophy index and myocardial interstitial collagen deposition in the peri-infarct myocardium. These effects were accompanied by attenuation in the rise of transforming growth factor-β, collagen I, and collagen III, as well as the fetal genes (atrial natriuretic peptide, B-type natriuretic peptide, and beta myosin heavy chain) expression in the peri-infarct region. In addition, the expression of Hif1α and vascular endothelial growth factor significantly increased compared with all groups.

CONCLUSIONS

Cardiac TRH inhibition improves LV systolic function and attenuates ventricular remodeling after MI. These novel findings support the idea that TRH inhibition may serve as a new therapeutic strategy against the progression of heart failure.

Usefulness of cardiac biomarkers for prognosis of better outcomes in chronic heart failure: Retrospective 18-year follow-up study

Brain natriuretic peptide is an established, surrogate follow-up marker, strongly correlated with heart failure severity. Several other biomarkers and tests are useful for assessing the prognosis of patients with HF, such as oxidized low-density lipoprotein antibodies and C-reactive protein. Some inflammatory cells, including monocytes, lymphocytes, and neutrophils, are involved in coronary heart disease and may be useful for prognosis also. This study assessed the potential usefulness of various laboratory biomarkers in predicting long-term outcomes and hospitalization among a cohort of outpatients with chronic, advanced HF.This retrospective, 18-year follow-up study included all patients admitted to the Heart Failure Outpatient Unit in our tertiary care medical center from 2000 through 2001 due to chronic HF. Excluded were patients with malignant disease, severe stroke, active inflammatory disease, or infection. At the first visit, blood was sampled for routine analysis and biomarkers NT-proBNP, C-reactive protein, myeloperoxidase, heat shock protein, and antibodies to oxidized low density lipoprotein. left ventricular ejection fraction and New York Heart Association class class were also established. Patients were followed every 3 months. Study endpoints were mortality or first hospitalization.Among 305 study patients, HF duration ranged from 2 months to 18 years. Mean follow-up was 9.1 ± 6 years. Mean time to first hospitalization was 60 ± 58.1 months, median = 38 (range 0-179). Mortality rate was 41%. Regression analysis showed New York Heart Association class, lymphocyte count and alkaline phosphatase were independent predictors of survival, with hazard ratios of 1.0, 0.973, and 1.006, respectively (P < .05).N-terminal pro-B-type natriuretic peptide, alkaline phosphatase, and lymphocyte count are important prognostic predictors for very long-term follow-up among patients with chronic HF.

Cardiac hypertrophy in a dish: a human stem cell based model

Cardiac hypertrophy is an important and independent risk factor for the development of heart failure. To better understand the mechanisms and regulatory pathways involved in cardiac hypertrophy, there is a need for improved in vitro models. In this study, we investigated how hypertrophic stimulation affected human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs). The cells were stimulated with endothelin-1 (ET-1) for 8, 24, 48, 72, or 96 h. Parameters including cell size, ANP-, proBNP-, and lactate concentration were analyzed. Moreover, transcriptional profiling using RNA-sequencing was performed to identify differentially expressed genes following ET-1 stimulation. The results show that the CMs increase in size by approximately 13% when exposed to ET-1 in parallel to increases in ANP and proBNP protein and mRNA levels. Furthermore, the lactate concentration in the media was increased indicating that the CMs consume more glucose, a hallmark of cardiac hypertrophy. Using RNA-seq, a hypertrophic gene expression pattern was also observed in the stimulated CMs. Taken together, these results show that hiPSC-derived CMs stimulated with ET-1 display a hypertrophic response. The results from this study also provide new molecular insights about the underlying mechanisms of cardiac hypertrophy and may help accelerate the development of new drugs against this condition.

Thymoquinone attenuates doxorubicin-cardiotoxicity in rats

Contrary to the fact that doxorubicin is a powerful chemotherapeutic agent for the treatment of neoplastic diseases, cardiotoxicity is too important to be ignored. Thymoquinone serves as a powerful free radical scavenger. In the study, the effects of thymoquinone against doxorubicin-cardiotoxicity will be evaluated. Forty rats were divided into five groups. Group I: control group (n = 8); group II: olive oil group (n = 8); group III: thymoquinone group (n = 8); given 10 mg/kg thymoquinone intraperitoneally per day throughout the experiment; group IV: doxorubicin group (n = 8); injected with a single dose of 15 mg/kg ip doxorubicin on the 7th day of the experiment; group V: doxorubicin + thymoquinone group (n = 8); administered with 10 mg/kg thymoquinone per day during the experiment and 15 mg/kg doxorubicin ip on the 7th day. The experiment was planned for 14 days. Immunohistochemically, heat shock protein (HSP) 70 and HSP90, glucose-regulated protein 78 (GRP78), caspase-3 were stained. We made terminal deoxynucleotidyl transferase dUTP nick end labeling for apoptotic evaluation. Total oxidant status (TOS) levels and total antioxidant status (TAS) were measured in the heart tissue. Atrial natriuretic peptide (ANP) and pro-B type natriuretic peptide (proBNP) were evaluated. In the study, HSP70, HSP90, GRP78, and caspase-3 levels increased in group IV. TOS and TAS levels were significant compared to group I. Doxorubicin significantly increased ANP and NT-proBNP levels. Thymoquinone revealed significant differences in these values. Thymoquinone can be an important cardioprotective agent against doxorubicin-cardiotoxicity.

Stress proteins: the biological functions in virus infection, present and challenges for target-based antiviral drug development

Stress proteins (SPs) including heat-shock proteins (HSPs), RNA chaperones, and ER associated stress proteins are molecular chaperones essential for cellular homeostasis. The major functions of HSPs include chaperoning misfolded or unfolded polypeptides, protecting cells from toxic stress, and presenting immune and inflammatory cytokines. Regarded as a double-edged sword, HSPs also cooperate with numerous viruses and cancer cells to promote their survival. RNA chaperones are a group of heterogeneous nuclear ribonucleoproteins (hnRNPs), which are essential factors for manipulating both the functions and metabolisms of pre-mRNAs/hnRNAs transcribed by RNA polymerase II. hnRNPs involve in a large number of cellular processes, including chromatin remodelling, transcription regulation, RNP assembly and stabilization, RNA export, virus replication, histone-like nucleoid structuring, and even intracellular immunity. Dysregulation of stress proteins is associated with many human diseases including human cancer, cardiovascular diseases, neurodegenerative diseases (e.g., Parkinson’s diseases, Alzheimer disease), stroke and infectious diseases. In this review, we summarized the biologic function of stress proteins, and current progress on their mechanisms related to virus reproduction and diseases caused by virus infections. As SPs also attract a great interest as potential antiviral targets (e.g., COVID-19), we also discuss the present progress and challenges in this area of HSP-based drug development, as well as with compounds already under clinical evaluation.

Heat-shock proteins in diagnosis and treatment: an overview of different biochemical and immunological functions

Heat-shock proteins (HSPs) have been involved in different functions including chaperone activity, protein folding, apoptosis, autophagy and immunity. The HSP families have powerful effects on the stimulation of innate immune responses through Toll-like receptors and scavenger receptors. Moreover, HSP-mediated phagocytosis directly enhances the processing and presentation of internalized antigens via the endocytic pathway in adaptive immune system. These properties of HSPs have been used for development of prophylactic and therapeutic vaccines against infectious and noninfectious diseases. Several studies also demonstrated the relationship between HSPs and drug resistance as well as their use as a novel biomarker for detecting tumors in patients. The present review describes different roles of HSPs in biology and medicine especially biochemical and immunological aspects.

Effects of heme oxygenase-1 upregulation on isoproterenol-induced myocardial infarction

The present study was designed to examine the effect of heme oxygenase-1 (HO-1) induction by cobalt protoporphyrin (CoPP) on the cardiac functions and morphology, electrocardiogram (ECG) changes, myocardial antioxidants (superoxide dismutase [SOD] and glutathione [GSH]), and expression of heat shock protein (Hsp) 70 and connexin 43 (Cx-43) in myocardial muscles in isoproterenol (ISO) induced myocardial infarction (MI). Thirty two adult male Sprague Dawely rats were divided into 4 groups (each 8 rats): normal control (NC) group, ISO group: received ISO at dose of 150 mg/kg body weight intraperitoneally (i.p.) for 2 successive days; ISO + Trizma group: received (ISO) and Trizma (solvent of CoPP) at dose of 5 mg/kg i.p. injection 2 days before injection of ISO, with ISO at day 0 and at day 2 after ISO injections; and ISO + CoPP group: received ISO and CoPP at a dose of 5 mg/kg dissolved in Trizma i.p. injection as Trizma. We found that, administration of ISO caused significant increase in heart rate, corrected QT interval, ST segment, cardiac enzymes (lactate dehydrogenase, creatine kinase-muscle/brain), cardiac HO-1, Hsp70 with significant attenuation in myocardial GSH, SOD, and Cx-43. On the other hand, administration of CoPP caused significant improvement in ECG parameters, cardiac enzymes, cardiac morphology; antioxidants induced by ISO with significant increase in HO-1, Cx-43, and Hsp70 expression in myocardium. In conclusions, we concluded that induction of HO-1 by CoPP ameliorates ISO-induced myocardial injury, which might be due to up-regulation of Hsp70 and gap junction protein (Cx-43).

The Expression of and Preoperative Correlation between Heat-Shock Protein 70, EuroSCORE, and Lactate in Patients undergoing CABG with Cardiopulmonary Bypass

Objetive

Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) improved symptoms and increased survival and quality of life in patients with coronary artery disease. However, it should be the main cause of a complex organic systemic inflammatory response that greatly contributes to several postoperative adverse effects.

Methods

We aimed to evaluate heat-shock protein 70 (HSP 70) expression as a morbimortality predictor in patients with preserved ventricular function undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) and to determine their association with the lactate as a marker of tissue hypoperfusion and the EuroSCORE risk score. This is a prospective, observational study including 46 patients and occurring between May and July 2016. Patients without ventricular dysfunction undergoing myocardial revascularization with extracorporeal circulation were included. They were divided into (1) complicated and (2) uncomplicated postoperative evolution groups. EuroSCORE, lactate levels, and HSP 70 expression and their correlations were determined.

Results

Statistical analysis showed that the group with complicated evolution had higher EuroSCORE values than the other group. HSP 70 protein levels were significantly increased in the group with uncomplicated evolution and showed similar results. According to our results, HSP family proteins may be independent predictors of uncomplicated evolution in patients without ventricular dysfunction undergoing CABG with CPB.

Conclusion

HSP 70 should be a good discriminator and protection marker for complications in cardiac surgery.

Heat Shock Proteins: Protection and Potential Biomarkers for Ischemic Injury of Cardiomyocytes After Surgery

The heat shock proteins are endogenous proteins with the ability to act as molecular chaperones. Methods that provide cell protection by way of some damage can positively influence the results of surgery. The present review summarizes current knowledge concerning the cardioprotective role of the heat shock proteins as occurs in heart damage, including relevant information about the stresses that regulate the expression of these proteins and their potential role as biomarkers of heart disease.

Elevated heat shock proteins in bipolar disorder patients with hypothalamic pituitary adrenal axis dysfunction

BACKGROUND

Heat shock proteins (HSP) might be useful as biomarkers for bipolar disorder (BD) which would be clinically valuable since no reliable biomarker for BD has so far been identified. The purpose of this study was to assess the heat shock proteins CPN10, CPN60, and CPN70 as potential biomarkers of BD.

METHODS

The study included 100 BD patients recruited from a hospital during 2012 and 2013. The study also included 94 healthy controls. Among the BD patients, 33 had abnormal hypothalamic-pituitary-adrenal (HPA) axis activity. Blood samples were obtained from the patients and controls. The chemiluminescence method, mass spectrometry, and flow cytometry were used for analysis.

RESULTS

The BD patients compared with the controls had a significantly lower level of CPN10 and significantly higher levels of CPN60 and CPN70. The BD patients with abnormal HPA axis activity had a significantly lower level of CPN60 compared with the normal HPA axis activity group of BD patients. The CPN60 level significantly inversely correlated with adrenocorticotropic hormone (ACTH) level in patients with bipolar depression and in patients with bipolar hypomania, and CPN70 significantly correlated with ACTH level in patients with bipolar depression and hypomania.

CONCLUSIONS

Our findings suggest that the heat shock proteins CPN10, CPN60, and CPN70 might have potential as biomarkers for BD and CPN60 blood level might distinguish patients with abnormal HPA axis activity from those with normal HPA axis activity.

Identification of key genes and miRNAs associated with carotid atherosclerosis based on mRNA-seq data

This study was aimed to explore the crucial genes and microRNAs (miRNAs) associated with the carotid atherosclerosis (CA).Two public datasets GSE28829 and GSE43292 were obtained from Gene Expression Omnibus databases to analyze the differentially expressed genes (DEGs) between primary and advanced atherosclerotic plaque tissues. The Gene Ontology (GO) terms, pathways, and protein-protein interactions (PPIs) of these DEGs were analyzed. miRNAs and transcription factor (TF) were predicted.A total of 112 upregulated and 179 downregulated intersection DEGs were identified between 2 datasets. In the PPI network, HSP90AB1 (degree = 19), RAP1A (degree = 14), and integrin subunit beta 1 (ITGB1) had higher degrees. A total of 23 miRNAs were predicted, such as miR-126, miR-155, miR-19A, and miR-19B. Four TFs were associated with upregulated DEGs, while 10 TFs were identified to be associated with downregulated genes.Our study suggests the important roles of HSP90AB1, RAP1A, and integrins proteins of ITGB1, ITGA11, ITGA9, and ITGB2 in the progression of CA plaque. Additionally, miR-126, miR-155, miR-19B, and miR-19A may be considered as biomarkers of CA.

Exercise Training under Exposure to Low Levels of Fine Particulate Matter: Effects on Heart Oxidative Stress and Extra-to-Intracellular HSP70 Ratio

Fine particulate matter (PM_2.5) promotes heart oxidative stress (OS) and evokes anti-inflammatory responses observed by increased intracellular 70 kDa heat shock proteins (iHSP70). Furthermore, PM_2.5 increases the levels of these proteins in extracellular fluids (eHSP70), which have proinflammatory roles. We investigated whether moderate and high intensity training under exposure to low levels of PM_2.5 modifies heart OS and the eHSP70 to iHSP70 ratio (H-index), a biomarker of inflammatory status. Male mice (n = 32), 30 days old, were divided into six groups for 12 weeks: control (CON), moderate (MIT) and high intensity training (HIT), exposure to 5 μg of PM_2.5 daily (PM_2.5), and moderate and high intensity training exposed to PM_2.5 (MIT + PM_2.5 and HIT + PM_2.5 groups). The CON and PM_2.5 groups remained sedentary. The MIT + PM_2.5 group showed higher heart lipid peroxidation levels than the MIT and PM_2.5 groups. HIT and HIT + PM_2.5 showed higher heart lipid peroxidation levels and lower eHSP70 and H-index levels compared to sedentary animals. No alterations were found in heart antioxidant enzyme activity or iHSP70 levels. Moderate exercise training under exposure to low levels of PM_2.5 induces heart OS but does not modify eHSP70 to iHSP70 ratio (H-index). High intensity exercise training promotes anti-inflammatory profile despite exposure to low levels of PM_2.5.

Heart irradiation reduces microvascular density and accumulation of HSPA1 in mice

PURPOSE

Improvement of radiotherapy techniques reduces the exposure of normal tissues to ionizing radiation. However, the risk of radiation-related late effects remains elevated. In the present study, we investigated long-term effects of radiation on heart muscle morphology.

MATERIALS AND METHODS

We established a mouse model to study microvascular density (MVD), deposition of collagen fibers, and changes in accumulation of heat shock 70 kDa protein 1 (HSPA1) in irradiated heart tissue. Hearts of C57BL/6 mice received a single dose of X‑ray radiation in the range 0.2-16 Gy. Analyses were performed 20, 40, and 60 weeks after irradiation.

RESULTS

Reduction in MD was revealed as a long-term effect observed 20-60 weeks after irradiation. Moreover, a significant and dose-dependent increase in accumulation of HSPA1, both cytoplasmic and nuclear, was observed in heart tissues collected 20 weeks after irradiation. We also noticed an increase in collagen deposition in hearts treated with higher doses.

CONCLUSIONS

This study shows that some changes induced by radiation in the heart tissue, such as reduction in microvessel density, increase in collagen deposition, and accumulation of HSPA1, are observed as long-term effects which might be associated with late radiation cardiotoxicity.

HSP70 is associated with the severity of inflammation in chronic rhinosinusitis

BACKGROUND

Nasal secretions include cytokines and inflammatory mediators that are involved in the pathogenesis of upper airway inflammation.

OBJECTIVE

We tried to find unknown biomolecules that are involved in the pathogenesis of chronic rhinosinusitis (CRS).

METHODS

We collected nasal mucosal secretions from patients who were diagnosed as having CRS and who underwent endoscopic sinus surgery. A total of 63 patients who underwent nasal secretion collection were reviewed. Enzyme-linked immunosorbent assay was performed by using nasal lavage samples to evaluate which biomolecules were associated with the severity of inflammation based on the Lund-Mackay score. By using human nasal epithelial cells, we performed Western blot, real-time polymerase chain reaction, and enzyme-linked immunosorbent assay to evaluate the secretory mechanism of heat shock protein (HSP) 70.

RESULTS

We found that the level of interleukin 8 and HSP70 were significantly associated with the Lund-Mackay score and interleukin 17C, C-X-C motif chemokine 10, and HSP27 were not significantly associated. HSP70 was also significantly associated with the surgical outcome of the enrolled patients. Furthermore, we found that exposure to hypoxia and treatment of lipoteichoic acid induced the secretion of HSP70 but that lipopolysaccharide did not induce the secretion of HSP70 in human nasal epithelial cells.

CONCLUSION

Our findings indicated that HSP70 might play a role in the pathogenesis of CRS and the possibility of HSP70 as a biomolecule that represents the severity of CRS.

Post-translational regulation of neuronal nitric oxide synthase: implications for sympathoexcitatory states

INTRODUCTION

Nitric oxide (NO) synthesized via neuronal nitric oxide synthase (nNOS) plays a significant role in regulation/modulation of autonomic control of circulation. Various pathological states are associated with diminished nNOS expression and blunted autonomic effects of NO in the central nervous system (CNS) including heart failure, hypertension, diabetes mellitus, chronic renal failure etc. Therefore, elucidation of the molecular mechanism/s involved in dysregulation of nNOS is essential to understand the pathogenesis of increased sympathoexcitation in these diseased states. Areas covered: nNOS is a highly regulated enzyme, being regulated at transcriptional and posttranslational levels via protein-protein interactions and modifications viz. phosphorylation, ubiquitination, and sumoylation. The enzyme activity of nNOS also depends on the optimal concentration of substrate, cofactors and association with regulatory proteins. This review focuses on the posttranslational regulation of nNOS in the context of normal and diseased states within the CNS. Expert opinion: Gaining insight into the mechanism/s involved in the regulation of nNOS would provide novel strategies for manipulating nNOS directed therapeutic modalities in the future, including catalytically active dimer stabilization and protein-protein interactions with intracellular protein effectors. Ultimately, this is expected to provide tools to improve autonomic dysregulation in various diseases such as heart failure, hypertension, and diabetes.

The human HSP70 family of chaperones: where do we stand?

The 70-kDa heat shock protein (HSP70) family of molecular chaperones represents one of the most ubiquitous classes of chaperones and is highly conserved in all organisms. Members of the HSP70 family control all aspects of cellular proteostasis such as nascent protein chain folding, protein import into organelles, recovering of proteins from aggregation, and assembly of multi-protein complexes. These chaperones augment organismal survival and longevity in the face of proteotoxic stress by enhancing cell viability and facilitating protein damage repair. Extracellular HSP70s have a number of cytoprotective and immunomodulatory functions, the latter either in the context of facilitating the cross-presentation of immunogenic peptides via major histocompatibility complex (MHC) antigens or in the context of acting as "chaperokines" or stimulators of innate immune responses. Studies have linked the expression of HSP70s to several types of carcinoma, with Hsp70 expression being associated with therapeutic resistance, metastasis, and poor clinical outcome. In malignantly transformed cells, HSP70s protect cells from the proteotoxic stress associated with abnormally rapid proliferation, suppress cellular senescence, and confer resistance to stress-induced apoptosis including protection against cytostatic drugs and radiation therapy. All of the cellular activities of HSP70s depend on their adenosine-5'-triphosphate (ATP)-regulated ability to interact with exposed hydrophobic surfaces of proteins. ATP hydrolysis and adenosine diphosphate (ADP)/ATP exchange are key events for substrate binding and Hsp70 release during folding of nascent polypeptides. Several proteins that bind to distinct subdomains of Hsp70 and consequently modulate the activity of the chaperone have been identified as HSP70 co-chaperones. This review focuses on the regulation, function, and relevance of the molecular Hsp70 chaperone machinery to disease and its potential as a therapeutic target.

Soluble Glycoprotein 130 and Heat Shock Protein 27 as Novel Candidate Biomarkers of Chronic Heart Failure with Preserved Ejection Fraction

BACKGROUND

Despite their importance, the current clinical biomarkers of chronic heart failure have limitations. In this study, soluble glycoprotein 130 (sgp130), heat shock protein 27 (hsp27), dipeptidyl peptidase IV (dpp4) and cathepsin S (CTSS) were tested for their potential as novel biomarkers for diagnosing chronic heart failure (CHF) with preserved ejection fraction.

METHODS

We compared the circulating levels of sgp130, hsp27, dpp4, and cathepsin S in patients with CHF with preserved ejection fraction (n=50) and in controls (n=50), determined how well these candidate biomarkers distinguish patients with CHF from controls, and assessed whether these candidates are superior to N-terminal pro brain natriuretic peptide (NT-pro-BNP) as diagnostic tools.

RESULTS

After adjusting for clinical covariates, patients with CHF showed significantly higher mean concentrations of sgp130 (317.38pg/ml vs. 215.90 pg/ml), hsp27 (2601.02 pg/ml vs. 923.61 pg/ml) and NT-pro-BNP (982.35 pg/ml vs. 331.99 pg/ml), but not dpp4 (6930.9 4pg/ml vs. 7081.37 pg/ml) or CTSS (1050.46 pg/ml vs. 984.96 pg/ml), than did controls. In the receiver operating characteristic curve analysis, hsp27 showed the most notable difference between CHF patients and controls, with the largest area under the curve (AUC) (0.920); the AUC values for sgp130 and NT-pro-BNP were 0.877 and 0.882, respectively.

CONCLUSIONS

Soluble glycoprotein 130 and hsp27 are novel candidate biomarkers for diagnosing CHF with preserved ejection fraction and thus warrant further investigation; neither dpp4 nor CTSS showed promise as biomarkers of CHF.

Expression of calcineurin, calpastatin and heat shock proteins during ischemia and reperfusion

Objective

Calcineurin (CaN) interacts with calpains (Calpn) and causes cellular damage eventually leading to cell death. Calpastatin (Calp) is a specific Calpn inhibitor, along with CaN stimulation has been implicated in reduced cell death and self-repair. Molecular chaperones, heat shock proteins (Hsp70 and Hsp90) acts as regulators in Calpn signaling. This study aims to elucidate the role of CaN, Calp and Hsps during induced ischemia and reperfusion in primary cardiomyocyte cultures (murine).

Methods and results

Protein expression was analyzed concurrently with viability using flow cytometry (FACS) in ischemia- and reperfusion-induced murine cardiomyocyte cultures. The expression of Hsp70 and Hsp90, both being molecular chaperones, increased during ischemia with a concurrent increase in death of cells expressing these proteins. The relative expression of Hsp70 and Hsp90 during ischemia with respect to CaN was enhanced in comparison to Calp. Reperfusion slightly decreased the number of cells expressing these chaperones. There was no increase in death of cells co-expressing Hsp70 and Hsp90 along with CaN and Calp. CaN expression peaked during ischemia and subsequent reperfusion reduced its expression and cell death. Calp expression increased both during ischemia and subsequent reperfusion but cell death decreased during reperfusion.

Conclusion

The present study adds to the existing knowledge that Hsp70, Hsp90, CaN and Calp interact with each other and play significant role in cardio protection.

•

Differential expression of calcineurin and calpastatin during ischemia and reperfusion.

•

Enhanced ischemia induced cell death in cells expressing Hsp70 and Hsp90.

•

Cardio protective role of calcineurin, calpastatin, Hsp70 and Hsp90.

Class III PI3K-mediated prolonged activation of autophagy plays a critical role in the transition of cardiac hypertrophy to heart failure

Pathological cardiac hypertrophy often leads to heart failure. Activation of autophagy has been shown in pathological hypertrophic hearts. Autophagy is regulated positively by Class III phosphoinositide 3-kinase (PI3K). However, it is unknown whether Class III PI3K plays a role in the transition of cardiac hypertrophy to heart failure. To address this question, we employed a previously established cardiac hypertrophy model in heat shock protein 27 transgenic mice which shares common features with several types of human cardiomyopathy. Age-matched wild-type mice served as control. Firstly, a prolonged activation of autophagy, as reflected by autophagosome accumulation, increased LC3 conversion and decreased p62 protein levels, was detected in hypertrophic hearts from adaptive stage to maladaptive stage. Moreover, morphological abnormalities in myofilaments and mitochondria were presented in the areas accumulated with autophagosomes. Secondly, activation of Class III PI3K Vacuolar protein sorting 34 (Vps34), as demonstrated by upregulation of Vps34 expression, increased interaction of Vps34 with Beclin-1, and deceased Bcl-2 expression, was demonstrated in hypertrophic hearts from adaptive stage to maladaptive stage. Finally, administration with Wortmaninn, a widely used autophagy inhibitor by suppressing Class III PI3K activity, significantly decreased autophagy activity, improved morphologies of intracellular apartments, and most importantly, prevented progressive cardiac dysfunction in hypertrophic hearts. Collectively, we demonstrated that Class III PI3K plays a central role in the transition of cardiac hypertrophy to heart failure via a prolonged activation of autophagy in current study. Class III PI3K may serve as a potential target for the treatment and management of maladaptive cardiac hypertrophy.

Effects of Lycium barbarum polysaccharides on oxidative stress in hyperlipidemic mice following chronic composite psychological stress intervention

Chronic composite psychological stress intervention is the accumulation of factors which may induce psychological stress, including food deprivation, water deprivation and swimming in cold water. Approximately 40% of cases of atherosclerosis are associated with chronic composite psychological stress. The aim of the present study was to explore the effects of Lycium barbarum polysaccharides (LBP) on blood lipid levels and oxidative stress in hyperlipidemic mice, following chronic composite psychological stress. A hyperlipidemic mouse model was generated, and the mice were subjected to chronic composite psychological stress and treated with LBP for 30 days. After 30 days the triglyceride (TG) and total cholesterol (TC) levels were measured in the serum, and the mRNA expression levels of cholesterol 7α‑hydroxylase (CYP7A1) were determined in the liver, in order to observe any changes to lipid metabolism. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were measured in the liver to evaluate the effects of LBP on oxidative stress. The blood serum levels of interleukin‑6 (IL‑6) and heat shock protein 70 (HSP‑70) were measured to evaluate the extent of the aortic inflammatory response, and to determine the protective effects of LBP. The levels of TG, TC, MDA and IL‑6 were significantly higher in the mice subjected to chronic composite psychological stress (HS), as compared with the mice treated with LBP alone (HL), or treated with LBP and subjected to stress (HLS). In addition, SOD and HSP‑70 levels, and the mRNA expression levels of CYP7A1 were significantly lower in the HS group, as compared with that in the HL and HLS groups. These results suggest that chronic composite psychological stress may promote the occurrence and development of atherosclerosis, by inducing the aortic inflammatory response and lipid peroxidation. Furthermore, treatment with LBP significantly inhibited oxidative stress and the aortic inflammatory response.

The role of heat shock proteins in atherosclerosis

Atherosclerosis is a chronic, multifactorial disease that starts in youth, manifests clinically later in life, and can lead to myocardial infarction, stroke, claudication, and death. Although inflammatory processes have long been known to be involved in atherogenesis, interest in this subject has grown in the past 30-40 years. Animal experiments and human analyses of early atherosclerotic lesions have shown that the first pathogenic event in atherogenesis is the intimal infiltration of T cells at arterial branching points. These T cells recognize heat shock protein (HSP)60, which is expressed together with adhesion molecules by endothelial cells in response to classic risk factors for atherosclerosis. Although these HSP60-reactive T cells initiate atherosclerosis, antibodies to HSP60 accelerate and perpetuate the disease. All healthy humans develop cellular and humoral immunity against microbial HSP60 by infection or vaccination. Given that prokaryotic (bacterial) and eukaryotic (for instance, human) HSP60 display substantial sequence homology, atherosclerosis might be the price we pay for this protective immunity, if risk factors stress the vascular endothelial cells beyond physiological conditions.

Danger signals in the initiation of the inflammatory response after myocardial infarction

During myocardial infarction, sterile inflammation occurs. The danger model is a solid theoretic framework that explains this inflammation as danger associated molecular patterns activate the immune system. The innate immune system can sense danger signals through different pathogen recognition receptors (PRR) such as toll-like receptors, nod-like receptors and receptors for advanced glycation endproducts. Activation of a PRR results in the production of cytokines and the recruitment of leukocytes to the site of injury. Due to tissue damage and necrosis of cardiac cells, danger signals such as extracellular matrix (ECM) breakdown products, mitochondrial DNA, heat shock proteins and high mobility box 1 are released. Matricellular proteins are non-structural proteins expressed in the ECM and are upregulated upon injury. Some members of the matricellular protein family (like tenascin-C, osteopontin, CCN1 and the galectins) have been implicated in the inflammatory and reparative responses following myocardial infarction and may function as danger signals. In a clinical setting, danger signals can function as prognostic and/or diagnostic biomarkers and for drug targeting. In this review we will provide an overview of the established knowledge on the role of danger signals in myocardial infarction and we will discuss areas of interest for future research.