Plasma Heat Shock Protein 70 Is Associated With the Onset of Acute Myocardial Infarction and Total Occlusion in Target Vessels

Serum oxidative stress factors predict myocardial ischemia reperfusion injury after percutaneous coronary intervention in patients with acute myocardial infarction and type 2 diabetes mellitus

Introduction

Serum oxidative stress factors may be considered to be essential parameters for indicating cell oxidative damage.

Aim

We designed this study to investigate the clinical diagnostic value of serum oxidative stress factors (superoxide dismutase (SOD), malondialdehyde (MDA), and myeloperoxidase (MPO)) combined with ischemia-modified albumin (IMA) and heat shock protein 70 (HSP70) for myocardial ischemia-reperfusion injury (MIRI) after percutaneous coronary intervention (PCI) in elderly patients with acute myocardial infarction (AMI) and type 2 diabetes mellitus (T2DM).

Material and methods

From November 2020 to August 2021, 94 patients with AMI + T2DM and 86 patients with AMI were enrolled in the study; they were sub-grouped into the MIRI and non-MIRI groups following the occurrence of MIRI within 48 h after PCI. SOD, MDA, MPO, IMA, and HSP70 levels were determined. The clinical values of the combined serum oxidative stress factors, IMA, and HSP70 levels to predict MIRI events were analyzed.

Results

There was a higher probability of MIRI events in the AMI + T2DM group than the AMI group (p < 0.05). The ROC curve for the combined prediction of SOD, MDA, MPO, IMA, and HSP70 for the occurrence of MIRI events was higher in both the AMI and the AMI + T2DM groups than for predictive factors alone (all p < 0.05).

Conclusions

Combined prediction of SOD, MDA, MPO, IMA, and HSP70 has the highest diagnostic value for predicting MIRI events after PCI in AMI patients, especially in patients with AMI combined with T2DM.

Exogenous heat shock proteins HSPA1A and HSPB1 regulate TNF-α, IL-1β and IL-10 secretion from monocytic cells

Endogenous molecules, such as heat shock proteins (HSP), can function as danger signals when released into the extracellular environment in response to cell stress, where they elicit an immune response such as cytokine secretion. There has also been some suggestion that contamination of exogenous HSPs with lipopolysaccharide (LPS) may be responsible for these effects. This study investigates the effects of exogenous HSPA1A and HSPB1 on the activation of immune cells and the resulting secretion of cytokines, which are involved in inflammatory responses. To address whether exogenous HSPs can directly activate cytokine secretion, naïve U937 cells, differentiated U937 cells and peripheral blood mononuclear cells (PBMCs) were treated with either exogenously applied HSPA1A or HSPB1 and then secreted IL-1β, TNF-α and IL-10 were measured by ELISA. Both HSPs were able to induce a dose-dependent increase in IL-10 secretion from naïve U937 cells and dose-dependent IL-1β, TNF-α and IL-10 secretion were also observed in differentiated U937 cells and PBMCs. We also observed that CD14 affects the secretion levels of IL-1β, TNF-α and IL-10 from cells in response to exogenous HSP treatment. In addition, HSPA1A and HSPB1 were shown to interact with CD14, CD36 and CD11b extracellular receptor proteins. Several approaches used in this study indicate that HSP-induced cytokine secretion is largely independent of any contaminating LPS in the samples.

The Correlation between Extracellular Heat Shock Protein 70 and Lipid Metabolism in a Ruminant Model

Metabolic stress in early lactation cows is characterized by lipolysis, ketogenesis, insulin resistance and inflammation because of negative energy balance and increased use of lipids for energy needs. In this study the relationship between lipid metabolite, lipid-based insulin resistance, and hepatocyte functionality indexes and tumor necrosis factor alpha (TNF-α) with extracellular heat shock protein 70 (eHsp70) was investigated. The experiment included 50 cows and all parameters were measured in blood serum. In cows with a more pronounced negative energy balance, the following was determined: a higher concentration of eHsp70, TNF-α, non-esterified fatty acid (NEFA), beta-hydroxybutyrate (BHB), NEFA to insulin and NEFA to cholesterol ratio and lower concentration of cholesterol, very low-density lipoproteins (VLDL), low density lipoproteins (LDL) and liver functionality index (LFI). The eHsp70 correlated negatively with the values of cholesterol, VLDL, LDL, and triglycerides, while correlated positively with the level of NEFA and BHB. A higher concentration of eHsp70 suggests the development of fatty liver (due to a higher NEFA to cholesterol ratio and lower LFI) and insulin resistance (due to a lower revised quantitative insulin sensitivity check index RQUICKI-BHB and higher NEFA to insulin ratio). The eHsp70 correlated positively with TNF-α. Both TNF-α and eHsp70 correlated similarly to lipid metabolites. In cows with high eHsp70 and TNF-α values we found higher concentrations of NEFA, BHB, NEFA to insulin and NEFA to cholesterol ratio and a lower concentration of triglycerides and VLDL cholesterol compared to cows that had only high TNF-α values. Based on the positive correlation between eHsp70 and TNF-α, their similar relations, and the additional effect of eHsp70 (high TNF-α + eHsp70 values) on lipid metabolites we conclude that eHsp70 has pro-inflammatory effects implicating lipolysis, fatty liver, and fat tissue insulin resistance.