Serum antibody titers against heat shock protein 27 are associated with the severity of coronary artery disease

Mechanistic insights into heat shock protein 27, a potential therapeutic target for cardiovascular diseases

Heat shock protein 27 (HSP27) is a small chaperone protein that is overexpressed in a variety of cellular stress states. It is involved in regulating proteostasis and protecting cells from multiple sources of stress injury by stabilizing protein conformation and promoting the refolding of misfolded proteins. Previous studies have confirmed that HSP27 is involved in the development of cardiovascular diseases and plays an important regulatory role in this process. Herein, we comprehensively and systematically summarize the involvement of HSP27 and its phosphorylated form in pathophysiological processes, including oxidative stress, inflammatory responses, and apoptosis, and further explore the potential mechanisms and possible roles of HSP27 in the diagnosis and treatment of cardiovascular diseases. Targeting HSP27 is a promising future strategy for the treatment of cardiovascular diseases.

Circulating C1q/TNF-related protein-12 levels are associated with the severity of coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is the world's largest cause of death. The association of CAD with inflammation is well established. Recently, it has been confirmed that the C1q/TNF-related protein 12 (CTRP12) has a great anti-inflammatory effect. However, few data are available regarding the serum CTRP12 concentration levels in CAD patients.

OBJECTIVE

The study was performed to evaluate the correlation between the serum levels of CTRP12 and the CAD severity regarding to the number of affected vessels.

METHODS

About 200 suspected CAD patients and 50 healthy ones as a control, were evaluated based on case-control study. According to the results of angiography, patients were divided into CAD+ (n = 150) with any major coronary artery stenosis ≥50% and CAD- (n = 50) with <50% stenosis of the arteries. The CAD+patients were categorized into one- (1VD), two- (2VD) and three-vessel disease (3VD) based on the number of stenotic vessels. In the current study, different parameters such as CTRP12, tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), total oxidant status (TOS), total antioxidant capacity (TAC), and malondialdehyde (MDA) levels were evaluated, and also lipid profiles, hs-CRP and demographic factors were investigated as well.

RESULTS

Data revealed that CTRP12 and TAC levels in CAD + group were significantly lower than control subjects (P < 0.05). CTRP12 levels were found to be significantly lower in the 3VD compared with 1VD and 2VD subgroups (p < 0.01 and p < 0.05, respectively).

CONCLUSION

Our results confirmed that serum CTRP12 level is inversely associated with CAD severity. Therefore, it may be used as a prediction marker for CAD.

Effect of high-dose vitamin D supplementation on antibody titers to heat shock protein 27 in adolescent girls

Background Although vitamin D deficiency is associated with several inflammatory conditions, there have been few studies on the effects of vitamin D supplementation on markers of oxidative stress (OS) and inflammation. The aim of the current study was to evaluate the effects of high-dose vitamin D supplementation on heat shock protein 27 antibody (anti-Hsp27) titers in adolescent girls. Methods Five hundred and fifty adolescent girls received vitamin D3 at a dose of 50,000 IU/week for 9 weeks. Demographic, clinical and biochemical markers including serum fasting blood glucose (FBG), lipid profile and anti-Hsp27 titers as well as hematological parameters including white blood cell (WBC) count and red blood cell (RBC) distribution width (RDW) were determined in all the subjects at baseline and at the end of the study. Results Serum vitamin D significantly increased from 6.4 (4.2-9.6) ng/mL to 35.6 (25.8-47.5) ng/mL (p < 0.001) following the intervention. Furthermore, serum anti-Hsp27 titers were significantly lower after the 9-week vitamin D administration period (0.22 [0.12-0.33] optical density [OD] vs. 0.19 [0.11-0.31] OD; p = 0.002). A significant correlation was found between serum anti-Hsp27 and RDW (r = 0.13, p = 0.037). The reduction in RDW values after intervention was particularly evident in subjects with the greatest increase in serum vitamin D levels. Conclusions High-dose vitamin D supplementation was found to reduce antibody titers to Hsp27. Further randomized placebo-controlled trials are warranted to determine the long-term effect of vitamin D administration on the inflammatory process especially that associated with chronic disease.

Is there any association between Serum anti-HSP27 antibody level and the presence of metabolic syndrome; population based case-control study

Background: Heat shock protein 27 (HSP27) is an intracellular chaperone constitutively expressed in many cell types including cardio myocytes and endothelial cells. Circulating levels of HSP27 and anti-HSP27 antibody are higher in patients with CVD. Anti-HSP27 antibody concentrations were also reported to be increased in atherogenesis. We aimed to evaluate serum anti-HSP27 antibody titers in individuals with, or without, MetS in the MASHAD study cohort with large sample size in 6,568 subjects.

Methods: Participants with MetS were identified from MASHAD cohort (n=3358) using the IDF criteria, and the control group were those individuals who did not meet these criteria (n=3210). In-house enzyme-linked immune sorbent assay (ELISA) method was used for measuring Anti-HSP27 antibody levels. The two groups were matched for age, sex and smoking habit.

Results: As expected, there were significant differences in height (p= 0.004), waist and hip circumference, weight, BMI, systolic and diastolic blood pressure, TGs, TC, HDL-C, Hs-CRP, glucose, with the presence of diabetes mellitus, hypertension, hyperlipidemia (p<0.001) between the two groups. Serum HSP27 antibody titers did not show significant difference between the groups with and without metabolic syndrome (p= 0.740).

Conclusion: In conclusion, our results revealed serum anti-HSP27 antibody titers were not statistically different between individuals with and without MetS. However, it is possible that drug treatment may affect antibody titers and confound our findings in this population sample..

The Effects of Curcumin on Serum Heat Shock Protein 27 Antibody Titers in Patients with Metabolic Syndrome

Metabolic syndrome (MetS) is associated with an increased risk of cardiovascular disease and diabetes mellitus. Inflammation and oxidant stress are features of MetS that can enhance the expression and release of heat shock proteins (Hsps), including the small heat shock protein, Hsp 27, and that may subsequently lead to the production of Hsp27 antibodies (anti-Hsp 27). Curcumin is an anti-inflammatory and antioxidant phytochemical that may ameliorate these features of MetS. We investigated the effects of unformulated curcumin and phospholipidated curcumin on antibody titers to heat shock protein 27 (anti-Hsp 27) in patients with MetS. A randomized double-blind, placebo-controlled clinical trial design was used in 120 patients with MetS (diagnosed according to the International Diabetes Federation [IDF] criteria). Participants were randomly allocated to 3 groups, with 40 individuals per group, that received either 1 g/d curcumin, phospholipidated curcumin, or a placebo for 6 weeks. The changes in serum concentrations of anti-Hsp 27 did not differ significantly between study groups (p = .283). There was no significant difference between baseline and end-of-trial concentrations of anti-Hsp 27 in groups supplemented with curcumin (p = .177), phospholipidated curcumin (p = .798), or placebo (p = .663). Curcumin supplementation (1 g/d) has no significant effects on anti-Hsp 27 titers in patients with MetS.

Prophylactic salpingo-oophorectomy & surgical menopause for inherited risks of cancer: the need to identify biomarkers to assess the theoretical risk of premature coronary artery disease

Background

Some women with genetic risk of breast and/or ovarian cancer (e.g., BRCA1/2) opt to undergo prophylactic salpingo-oophorectomy (PSO, or surgical removal of the ovaries & fallopian tubes) in order to reduce their risk of cancer. As a consequence, these women experience “surgical menopause” – accompanied by more severe climacteric symptoms that occur in a much shorter time frame. While the risk of coronary artery disease (CAD) rises with menopause, little is known about how the sudden loss of ovarian function from PSO alters the whole-body physiology, and whether it predisposes women to premature CAD.

Methods/Design

To manage CAD risk there is a prerequisite for reliable biomarkers that can help guide risk assessment and therapeutic interventions. To address these needs, this prospective, observational cohort study will evaluate surrogate markers reflective of CAD health in women experiencing surgical menopause after PSO. Twenty women representing each of the following groups will be enrolled over 3 years (total participants = 240): (i) pre-menopausal PSO, (ii) post-menopausal PSO, (iii) pre-menopausal women undergoing other pelvic surgery, and (iv) pre-menopausal controls (no surgery). All participants will provide blood plasma samples pre- and 1, 3, 6, & 12 months post-operatively, with serial samples collectively assessed for measurements of the study’s primary endpoints of interest. These include a hormone profile (estradiol, follicle stimulating hormone (FSH), luteinizing hormone (LH), and progesterone) and both conventional (lipid profile) and novel biomarkers (Heat Shock Protein 27 (HSP27), HSP27-antibodies (HSP27 Ab), proprotein convertase subtilisin/kexin 9 (PCSK9), inflammatory cytokines) of CAD. Another aspect of this study is the measurement and analysis of retinal vessel diameters – an emerging physiological parameter reflective of CAD risk. Finally, a patient engagement exercise will result in the drafting of patient-generated questionnaires that address the well-being and health concerns of these women as they transition through premature menopause and work with our research team to identify and discuss their health priorities.

Discussion

The protocol of our planned study investigating the effects of PSO on CAD is described herein. Characterization of novel CAD markers in women experiencing surgical menopause will yield new insights into the role of the functional ovary in modulating lipid parameters and other CAD risk factors such as HSP27 and HSP27 Ab.

Extracellular Release and Signaling by Heat Shock Protein 27: Role in Modifying Vascular Inflammation

Heat shock protein 27 (HSP27) is traditionally viewed as an intracellular chaperone protein with anti-apoptotic properties. However, recent data indicate that a number of heat shock proteins, including HSP27, are also found in the extracellular space where they may signal via membrane receptors to alter gene transcription and cellular function. Therefore, there is increasing interest in better understanding how HSP27 is released from cells, its levels and composition in the extracellular space, and the cognate cell membrane receptors involved in effecting cell signaling. In this paper, the knowledge to date, as well as some emerging paradigms about the extracellular function of HSP27 is presented. Of particular interest is the role of HSP27 in attenuating atherogenesis by modifying lipid uptake and inflammation in the plaque. Moreover, the abundance of HSP27 in serum is an emerging new biomarker for ischemic events. Finally, HSP27 replacement therapy may represent a novel therapeutic opportunity for chronic inflammatory disorders, such as atherosclerosis.

GCAP1, Rab6, and HSP27: Novel Autoantibody Targets in Cancer-Associated Retinopathy and Autoimmune Retinopathy

PURPOSE

Autoantibodies (AAbs) with different retinal specificities were reported in cancer-associated retinopathy (CAR) and autoimmune retinopathy (AR). The goal was to identify the small retinal proteins of apparent molecular mass of 23-kDa often recognized by patients' AAbs.

METHODS

Sera specific for a 23-kDa retinal protein of 173 patients were investigated retrospectively by Western blotting and double immunofluorescence confocal microscopy. A proteomic analysis revealed new 23-kDa protein candidates, including guanylyl cyclase-activating proteins (GCAPs), heat shock protein 27 (HSP27), and Rab6A GTPase (Rab6A).

RESULTS

Among the cohort of 173 patients, only 68 had anti-recoverin AAbs and the remaining 105 reacted with 4 unique proteins, which were identified as a Rab6A, HSP27, GCAP1, and GCAP2. Confocal images from a double labeling study confirmed the reactivity of AAbs with different types of cells in human retina, consistent with the target protein's respective cellular functions. Patients (62/173) had been diagnosed with various kinds of cancer, including 20% of patients who had anti-recoverin, 11% anti-Rab6A, and 5% anti-HSP27 AAbs. Only 50% of recoverin-seropositive patients had cancer and the individuals with anti-recoverin AAbs had a significantly higher likelihood to be diagnosed with cancer than patients with other anti-23-kDa AAbs.

CONCLUSIONS

The newly discovered retinal autoantigens may be involved in pathogenicity of CAR and AR. The recognition of AAbs against various retinal proteins associated with autoimmune retinal degeneration broadens the group of proteins related with these entities.

TRANSLATIONAL RELEVANCE

Patients with anti-recoverin, anti-GCAP1, anti-Rab6A, and anti-HSP27 AAbs represented diverse clinical phenotypes, so the presence of disease-associated AAbs provides important information for molecular diagnosis.

Increased expression of phosphorylated forms of heat-shock protein-27 and p38MAPK in macrophage-rich regions of fibro-fatty atherosclerotic lesions in the rabbit

We aimed to assess the expression and distribution of Hsp27, pHsp27 (Ser82), p38MAPK and p-p38MAPK in fibro-fatty atherosclerotic lesions and the myocardium of hypercholesterolaemic rabbits. Male New Zealand white rabbits were fed a high-cholesterol diet for 18 weeks, maintaining serum cholesterol at approximately 20 mmol/l over this period. Aortic arch and myocardial tissues were analysed by Western blot, immunohistochemistry and double immunofluorescence. Plasma Hsp27 levels were measured by ELISA. There was a significant increase in the expression of monomeric and dimeric forms of Hsp27, together with pHsp27 (Ser82), p38MAPK and p-p38MAPK in the fibro-fatty atherosclerotic lesions (P < 0.01; P < 0.05; P < 0.001; and P < 0.001, respectively) and the myocardial tissues (P < 0.001) from the cholesterol-fed rabbits compared with equivalent tissues from controls when the plasma concentration was low. Immunohistochemical analysis of the fibro-fatty lesions showed marked increases in Hsp27 and pHsp27 (Ser82) immunoreactivity. Double immunostaining showed intense expression of pHsp27 and p-p38MAPK in regions that were rich in macrophages, suggesting a close association with these inflammatory cells, whereas, in regions rich in smooth muscle cells, only p-p38MAPK was found to be strongly expressed. An increased expression of pHsp27 (Ser82) was spatially associated with increased p-p38MAPK within fibro-fatty atherosclerotic lesions and was colocalized to regions rich in macrophages. The initial increase in plasma Hsp27 levels may reflect the increase in systemic inflammation and oxidative stress in the early phases of disease. The falling concentrations subsequently may be coincident with the development of the advanced atherosclerotic lesions.

Diagnosis and Therapy of Atrial Fibrillation: The Past, The Present and The Future

Atrial fibrillation (AF) is the most common age-related cardiac arrhythmia. It is a progressive disease, which makes treatment difficult. The progression of AF is caused by the accumulation of damage in cardiomyocytes which makes the atria more vulnerable for AF. Especially structural remodeling and electrical remodeling, together called electropathology are sustainable in the atria and impair functional recovery to sinus rhythm after cardioversion. The exact electropathological mechanisms underlying persistence of AF are at present unknown. High resolution wavemapping studies in patients with different types of AF showed that longitudinal dissociation in conduction and epicardial breakthrough were the key elements of the substrate of longstanding persistent AF. A double layer of electrically dissociated waves propagating transmurally can explain persistence of AF (Double Layer Hypothesis) but the molecular mechanism is unknown. Derailment of proteasis -defined as the homeostasis in protein synthesis, folding, assembly, trafficking, guided by chaperones, and clearance by protein degradation systems - may play an important role in remodeling of the cardiomyocyte. As current therapies are not effective in attenuating AF progression, step-by-step analysis of this process, in order to identify potential targets for drug therapy, is essential. In addition, novel mapping approaches enabling assessment of the degree of electropathology in the individual patient are mandatory to develop patient-tailored therapies. The aims of this review are to 1) summarize current knowledge of the electrical and molecular mechanisms underlying AF 2) discuss the shortcomings of present diagnostic instruments and therapeutic options and 3) to present potential novel diagnostic tools and therapeutic targets.

Plasma heat shock protein 27 is associated with coronary artery disease, abdominal aortic aneurysm and peripheral artery disease

Low protein levels of Hsp27 have been reported in atherosclerotic plaques. In addition, human studies have indicated that circulating Hsp27 levels are lower in coronary artery disease patients compared with controls. It remains, however, unclear whether this applies to other forms of atherosclerotic disease.

Plasma Hsp27 from 280 subjects was examined by ELISA. The cohort included 80 coronary artery disease (CAD), 40 peripheral artery disease (PAD) and 80 abdominal aortic aneurysm (AAA) patients. Eighty elderly subjects, without any clinical history of vascular diseases, were used as a control group. Receiver operating curve (ROC) and logistic regression model analysis were performed to evaluate the potential value of Hsp27 as a circulating biomarker.

Patients with atherosclerotic vascular diseases had significantly lower levels of Hsp27 than control subjects (p < 0.001). Moreover, Hsp27 was significantly lower in CAD patients than other atherosclerotic vascular disease groups (p < 0.001). There was no difference in Hsp27 levels between the AAA and PAD groups. Using the ROC-generated optimal cut-off values for Hsp27, logistic regression modeling indicated that low plasma Hsp27 was independently associated with the presence of multiple forms of atherosclerotic disease.

In conclusion, circulating Hsp27 is significantly lower in patients with multiple forms of atherosclerotic arterial disease.

Heat shock proteins and cardiovascular disease

Atherosclerosis is the leading global cause of mortality, morbidity, and disability. Heat shock proteins (HSPs) are a highly conserved family of proteins with diverse functions expressed by all cells exposed to environmental stress. Studies have reported that several HSPs may be potential risk markers of atherosclerosis and related cardiovascular diseases, or may be directly involved in the atherogenic process itself. HSPs are expressed by cells in atherosclerotic plaque and anti-HSP has been reported to be increased in patients with vascular disease. Autoimmune responses may be generated against antigens present within the atherosclerotic plaque, including HSP and may lead to a cycle of ongoing vascular injury. It has been suggested that by inducing a state of tolerance to these antigens, the atherogenic process may be limited and thus provide a potential therapeutic approach. It has been suggested that anti-HSPs are independent predictors of risk of vascular disease. In this review, we summarize the current understanding of HSP in cardiovascular disease and highlight their potential role as diagnostic agents and therapeutic targets.

Saffron in metabolic syndrome: its effects on antibody titers to heat-shock proteins 27, 60, 65 and 70

BACKGROUND

The metabolic syndrome is the most important risk factor for cardiovascular disease. The heat shock proteins (HSPs) are highly conserved families of proteins expressed by a number of cell types following exposure to stressful environmental conditions include several known risk factors for cardiovascular disease. Recent studies have shown the potential of constituents of saffron in the treatment of atherosclerosis. We aimed on investigating the effect of saffron on antibody titers to HSP in patients with metabolic syndrome.

METHODS

This was a randomized, placebo-controlled clinical trial. One-hundred and five subjects with metabolic syndrome were randomly allocated to one of the three groups: the case group received 100 mg/day saffron, the placebo control group received a capsule of placebo and a non-placebo control group received no capsule, for 12 weeks.

RESULTS

Antibodies against heat shock proteins 27, 60, 65 and 70 were determined in all patients before (week 0) and after (week 6 and 12) intervention. At 12 weeks, saffron produced a significantly decrease in AntiHSP27, 70 levels. Saffron can decrease AntiHSP27, 70 levels in patients with metabolic syndrome.

CONCLUSIONS

The results of this study indicate the efficacy of saffron in the improvement of some markers of autoimmunity HSPs in patients with metabolic syndrome.

Concept of atherosclerosis velocity: is it a better measure of cardiovascular risk?

In most cases atherosclerosis is the underlying cause of vascular diseases, including heart disease and stroke. It is believed that endothelial injury is the earliest change in the artery wall and that this precedes the formation of lesions of atherosclerosis. Recent developments in the field of atherosclerosis have led to a renewed interest in the recognition of the parameter of time in the atherosclerosis process. We believe that the factors determining the time-dependent rate of atherosclerosis progression are important, and it is in this context that we wish to propose for the first time the term "atherosclerosis velocity". In this review article, we summarize the existing evidence regarding atherosclerosis velocity and discuss the importance of this issue.

Evidence on the pathogenic role of auto-antibodies in acute cardiovascular diseases

Atherothrombosis is the major determinant of acute ischaemic cardiovascular events, such as myocardial infarction and stroke. Inflammatory processes have been linked to all phases of atherogenesis In particular, the identification of autoimmunity mediators in the complex microenvironment of chronic inflammation has become the focus of attention in both early and advanced atherogenic processes. Auto-antibodies against self-molecules or new epitopes generated by oxidative processes infiltrate atherosclerotic plaques and were shown to modulate the activity of immune cells by binding various types of receptors. However, despite mounting evidence for a pathophysiological role of autoantibodies in atherothrombosis, the clinical relevance for circulating autoantibodies in cardiovascular outcomes is still debated. This review aims at illustrating the mechanisms by which different types of autoantibodies might either promote or repress atherothrombosis and to discuss the clinical studies assessing the role of auto-antibodies as prognostic biomarkers of plaque vulnerability.

Increased serum heat shock protein 27 antibody titers and prooxidant-antioxidant balance in patients with beta-thalassemia major

OBJECTIVE

Determination of the serum heat shock protein 27 (Hsp27) antibody titers and prooxidant-antioxidant balance (PAB) in patients with thalassemia as markers of cell and oxidative stress, respectively.

METHODS

Serum PAB and anti-Hsp27 antibody titers were measured in 140 patients with thalassemia major and 140 sex- and age-matched healthy volunteers.

RESULTS

A significantly higher serum PAB value was observed in patients in comparison to controls. In the patient group, anti-Hsp27 antibody titers were significantly higher than for the control group (p < 0.001). We found a weak negative correlation between anti-Hsp27 antibody concentrations and the PAB (p = 0.03), but these values were not correlated with serum superoxide dismutase activity in the thalassemic patients.

CONCLUSIONS

Increased levels of serum PAB and Hsp27 antibodies may be involved in the pathological consequences of β-thalassemia major and may contribute to the development of endothelial injury.

Changes in anti-heat shock protein 27 antibody and C-reactive protein levels following cardiac surgery and their association with cardiac function in patients with cardiovascular disease

The relationship between serum anti-heat shock protein (Hsp)27 antibody and high sensitive C-reactive protein (hs-CRP) levels and indices of cardiac function were investigated in patients undergoing coronary artery bypass grafting (CABG) or heart valve replacement. The changes in anti-Hsp27 antibody titers and hs-CRP levels were compared among patients undergoing off-pump and on-pump CABG or valvular heart replacement. Fifty-three patients underwent off-pump, on-pump CABG, and heart valvular replacement in each group. Serum anti-Hsp27 titers and hs-CRP values were measured 24 h before and after the operation and at discharge. Echocardiography was performed before surgery and before discharge. The results were compared with values from 83 healthy controls. hs-CRP levels increased and anti-Hsp27 antibody decreased following surgery (P < 0.001 and P < 0.05, respectively), although these changes were independent of operative procedure (P = 0.361 and P = 0.120, respectively). Anti-Hsp27 antibody levels were higher at the time of discharge (P = 0.016). Only in coronary patients were anti-Hsp27 antibody levels negatively associated with E/E' (r = -0.268, P = 0.022), a marker of pulmonary capillary wedge pressure. In conclusions, anti-Hsp27 antibody levels are associated with indices of cardiac function in coronary patients. Cardiopulmonary bypass had no significant effect on the induction of changes in anti-Hsp27 levels. Moreover, anti-Hsp27 antibody levels fell in all groups postoperatively; this may be due to the formation of immune complexes of antigen-antibody, and antibody levels were higher at the time of discharge.

Coronary artery disease and its risk factors status in iran: a review

Background

Coronary artery disease (CAD) is a leading cause of mortality, morbidity, and disability in the world. The high prevalence and morbidity associated with CAD in Iran is one of the most pressing health problems.

Methods

We have reviewed the status of CAD and prevalence of its traditional and novel risk factors based on the published papers in recent years that may have an impact on the rate of CAD in Iran. Evaluation of current impact of metabolic syndrome in Iran was the other aim of this review, as it contributes to pathogenesis of coronary artery disease. We reviewed all PubMed indexed related studies. Some evidences from national articles which were published by the Ministry Of Health and Medical Education Research Council Certified Medical Journals of Islamic Republic of Iran were also included.

Results

The prevalence of CAD, coronary risk factors and metabolic syndrome in Iran is higher than Western countries and similar to some Middle East countries. There are limited data with regard to novel coronary risk factors in Iran.

Conclusion

Primary and secondary prevention of CAD including life style modifications and dietary interventions strongly recommended in Iranian population.