Predictive Value of Endoplasmic Reticulum Stress Markers in Low Ejection Fractional Heart Failure

Recent insights into the effect of endoplasmic reticulum stress in the pathophysiology of intestinal ischaemia‒reperfusion injury

Intestinal ischaemia‒reperfusion (I/R) injury is a surgical emergency. This condition is associated with a high mortality rate. At present, there are limited number of efficient therapeutic measures for this injury, and the prognosis is poor. Therefore, the pathophysiological mechanisms of intestinal I/R injury must be elucidated to develop a rapid and specific diagnostic and treatment protocol. Numerous studies have indicated the involvement of endoplasmic reticulum (ER) stress in the development of intestinal I/R injury. Specifically, the levels of unfolded and misfolded proteins in the ER lumen are increased due to unfolded protein response. However, persistent ER stress promotes apoptosis of intestinal mucosal epithelial cells through three signalling pathways in the ER, impairing intestinal mucosal barrier function and leading to the dysfunction of intestinal tissues and distant organ compartments. This review summarises the mechanisms of ER stress in intestinal I/R injury, diagnostic indicators, and related treatment strategies with the objective of providing novel insights into future therapies for this condition.

Identification of Ferroptosis-Related Genes in Heart Failure Induced by Transverse Aortic Constriction

Background

Heart failure (HF) is a common clinical syndrome due to ventricular dysfunction and is a major cause of mortality worldwide. Ferroptosis, marked by excessive iron-dependent lipid peroxidation, is closely related to HF. Therefore, the purpose of this study is to explore and validate ferroptosis-related markers in HF by bioinformatics analysis and animal experiments validation.

Materials and Methods

The gene expression profiles (GSE36074) of murine transverse aortic constriction (TAC) were obtained from the Gene Expression Omnibus (GEO); From the FerrDb database, ferroptosis-related genes (FRGs) were identified. Using GEO2R, differential expressed genes (DEGs) were screened. An overlapping analysis was conducted among DEGs and FRGs to identify ferroptosis-related DEGs (FRDEGs). We then performed clustering, functional enrichment analysis, and protein-protein interaction (PPI) analyses. In addition, the key FRDEGs were extracted by cytoHubba plugin and the networks of transcription factors (TFs)-key FRDEGs and microRNA-key FRDEGs were constructed. Lastly, the key FRDEGs were carried by quantitative reverse transcription PCR (RT-qPCR) and immunohistochemistry (IHC).

Results

Fifty-nine FRGs showing significantly different expression were identified from a total of 1918 DEGs in mice heart by transverse aortic constriction. GO and KEGG functional enrichment analysis revealed that these 59 ferroptosis-related DEGs mostly associated with positive regulation of apoptotic process, FoxO signaling pathway, VEGF signaling pathway, Apoptosis, Ferroptosis. Five key FRDEGs (Mapk14, Hif1a, Ddit3, Tlr4 and Ptgs2) were identified using PPI networks; Based on TFs-key FRDEGs networks, we found that Mapk14, Hif1a, Tlr4 and Ptgs2 were regulated by 3, 4, 5, and 29 TFs, respectively; however, Ddit3 was not regulated by any TF; By analyzing the miRNA-key FRDEGs networks, we found that 39, 74, 11, 28, and 18 miRNAs targets regulate the expression of Mapk14, Hif1a, Ddit3, Tlr4 and Ptgs2, respectively. Lastly, five key FRDEGs were validated at the mRNA and protein levels by RT-qPCR and IHC, which were in line with our bioinformatics analysis.

Conclusion

Our findings reveal that Mapk14, Hif1a, Ddit3, Tlr4 and Ptgs2 may be involved in the development of HF through regulating ferroptosis and as potential targets for HF.

The clinical significance of circulating glucose-regulated protein 78, Caspase-3, and C/EBP homologous protein levels in patients with heart failure

Background and aims

The destruction of endoplasmic reticulum (ER) homeostasis leads to heart failure (HF), which further aggravates ER stress. Limited data are available on the levels of ER stress markers in HF patients in clinical practice. This study aimed to determine the clinical significance of the ER stress markers, glucose-regulated protein 78 (GRP78), Caspase-3, and C/EBP homologous protein (CHOP), in predicting HF and its severity.

Materials and methods

A total of 62 patients with HF and 44 healthy controls were enrolled in the study, and all participants were followed-up for 2 years.

Results

Serum GRP78, Caspase-3, and CHOP levels were significantly higher in patients with HF than those in healthy controls. The level of GRP78 increased with the severity of HF. GRP78 levels were negatively correlated with left ventricular ejection fraction, and positively correlated with N-terminal B-type natriuretic peptide, D-dimer, and lactic acid. Serum GRP78 and Caspase-3 levels showed moderate predictive values for HF patients.

Conclusion

ER stress markers, GRP78 and Caspase-3, had a certain predictive value in HF and can be used as serum biomarkers for the diagnosis of HF. Additionally, GRP78 showed a certain predictive value in HF severity.

Pulmonary artery embolism: comprehensive transcriptomic analysis in understanding the pathogenic mechanisms of the disease

BACKGROUND

Pulmonary embolism (PE) is a severe disease that usually originates from deep vein thrombosis (DVT) of the lower extremities. This study set out to investigate the changes in the transcriptome of the pulmonary artery (PA) in the course of the PE in the porcine model.

METHODS

The study was performed on 11 male pigs: a thrombus was formed in each right femoral vein in six animals, and then was released to induce PE, the remaining five animals served as a control group. In the experimental animals total RNA was isolated from the PA where the blood clot lodged, and in the control group, from the corresponding PA segments. High-throughput RNA sequencing was used to analyse the global changes in the transcriptome of PA with induced PE (PA-E).

RESULTS

Applied multistep bioinformatics revealed 473 differentially expressed genes (DEGs): 198 upregulated and 275 downregulated. Functional Gene Ontology annotated 347 DEGs into 27 biological processes, 324 to the 11 cellular components and 346 to the 2 molecular functions categories. In the signaling pathway analysis, KEGG 'protein processing in endoplasmic reticulum' was identified for the mRNAs modulated during PE. The same KEGG pathway was also exposed by 8 differentially alternative splicing genes. Within single nucleotide variants, the 61 allele-specific expression variants were localised in the vicinity of the genes that belong to the cellular components of the 'endoplasmic reticulum'. The discovered allele-specific genes were also classified as signatures of the cardiovascular system.

CONCLUSIONS

The findings of this research provide the first thorough investigation of the changes in the gene expression profile of PA affected by an embolus. Evidence from this study suggests that the disturbed homeostasis in the biosynthesis of proteins in the endoplasmic reticulum plays a major role in the pathogenesis of PE.

High GRP78 levels in Covid-19 infection: A case-control study

Introduction

Covid-19 infection was declared a global pandemic by WHO on March 11, 2020. GRP78 protein is known to be involved in the intrusion of numerous viruses. Our current study tries to provide some insight into the variation of GRP78 protein levels in patients with Covid-19 (−) pneumonia, Covid-19 (+) pneumonia, and CT negative Covid-19 infection in comparison to the normal population through a larger number of cases.

Materials and methods

42 patients who have Covid-19 (−) pneumonia; 72 patients who have Covid-19 infection (30 pneumonia,42 CT negative patients) and 30 patient who have no known diseases (control group) have included in the study after the clinical and radiological evaluation. Serum GRP78 levels of the subjects were measured through a commercially available enzyme-linked immunosorbent assay (ELISA) kit.

Results

The GRP78 level was found to be significantly higher in the Covid-19 infection group than both Covid-19 (−) pneumonia and control group (p = 0.031 and p = 0.0001, respectively).No significant difference was evident between Covid-19 (−) pneumonia, Covid-19 (+) pneumonia and CT negative Covid 19 infection groups with respect to GRP78 levels (p = 0.09). In addition, the GRP78 levels were significantly higher in the Covid-19 (−) pneumonia group than the control group (p = 0.0001).

Conclusion

This prospective case-control study reveals that the serum GRP78 levels significantly increased during Covid-19 infection in comparison to both the Covid-19 (−) pneumonia and the control group. As the association between SARS-CoV-2 virus and GRP78 protein is revealed more clearly, this association may come to the fore as a therapeutic target.

Endoplasmic Reticulum Stress Markers in SARS-COV-2 Infection and Pneumonia: Case-Control Study

BACKGROUND/AIM

A novel human coronavirus, named SARS-COV-2, has recently caused thousands of deaths all around the world. Endoplasmic reticulum (ER) stress plays an important role in the development of diseases.

PATIENTS AND METHODS

We aimed to to investigate the relationship between ER stress markers in patients infected with SARS-COV-2 and patients with pneumonia. A total of 9 patients (4 patients diagnosed with pneumonia and 5 patients diagnosed with SARS-COV-2 infection) who admitted to the emergency Department with symptoms of pneumonia and SARS-COV-2 were included in the study. A total of 18 healthy individuals without any known chronic or acute disease and drug use were included as the healthy control group. Serum human glucose regulated protein 78 (GRP78), serum human C/EBP homologous protein (CHOP) and serum human phospho extracellular signal regulated kinase (PERK) levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

GRP78 levels were found to be significantly higher in SARS-COV-2 positive cases compared to individuals in other groups. Serum GRP-78 level median value was statistically significantly higher in SARS-COV-2-positive group compared to the other groups (p=0.0003). Serum PERK level was statistically significantly higher in SARS-COV-2-positive pneumonia cases (p=0.046).

CONCLUSION

An association was shown between GRP78 and SARS-COV-2 infection. Although a small number of patients was investigated, these results will be important and guide future treatments of SARS-COV-2.

Endoplasmic reticulum stress and focused drug discovery in cardiovascular disease

Endoplasmic reticulum (ER) is an intracellular membranous organelle involved in the synthesis, folding, maturation and post-translation modification of secretory and transmembrane proteins. Therefore, ER is closely related to the maintenance of intracellular homeostasis and the good balance between health and diseases. Endoplasmic reticulum stress (ERS) occurs when unfolded/misfolded proteins accumulate after disturbance of ER environment. In response to ERS, cells trigger an adaptive response called the Unfolded protein response (UPR), which helps cells cope with the stress. In recent years, a large number of studies show that ERS can aggravate cardiovascular diseases. ERS-related proteins expression in cardiovascular diseases is on the rise. Therefore, down-regulation of ERS is critical for alleviating symptoms of cardiovascular diseases, which may be used in the near future to treat cardiovascular diseases. This article reviews the relationship between ERS and cardiovascular diseases and drugs that inhibit ERS. Furthermore, we detail the role of ERS inhibitors in the treatment of cardiovascular disease. Drugs that inhibit ERS are considered as promising strategies for the treatment of cardiovascular diseases.