Method Article
The protocol describes the identification of several novel disulfideptosis-related differential genes associated with myocardial ischemia-reperfusion injury by bioinformatics analysis and experimental validation.
Myocardial ischemia-reperfusion injury (MIRI) is an additional injury that occurs during the process of restoring heart tissue blood flow after ischemia-induced injury. MIRI seriously affects the efficacy and short-term and long-term prognosis of reperfusion after myocardial infarction. At present, the mechanism of MIRI is not fully clear. Disulfideptosis is a novel mode of cell death, and the relationship between MIRI and disulfideptosis-related genes (DRGs) expression is still unclear. Firstly, this study explores the differentially expressed genes associated with disulfideptosis in MIRI through bioinformatics analysis. Secondly, by constructing a rat model of MIRI, DRGs were further detected. This study identified 12 related genes, including Myh9, SLC7A11, SLC3A2, Myh7b, ACTB, FLNB, Actn1, Actn4, Flnc, Dbn1 and Pdlim1. Myocardial tissue of rats with MIRI shows obvious pathological damage and apoptosis events. The results of immunohistochemistry indicated that MIRI stimulation increased the expression of GLUT1 protein in myocardial tissue but restricted the expression of F-actin protein. In addition, significant differences in the expression of three proteins were validated using external datasets and MIRI rat models. This study demonstrated that DRGs had significant predictive value in MIRI, providing new prospects for exploring biomarkers and potential therapeutic targets of MIRI.
Acute myocardial infarction (AMI) is a severe cardiovascular condition and remains a leading global cause of mortality. Percutaneous coronary intervention has significantly reduced mortality rates in AMI patients1. However, reperfusion therapy aimed at restoring myocardial blood supply is accompanied by a series of adverse pathological and physiological responses. These processes can result in an increased infarct size, myocardial cell death, sustained ventricular arrhythmias, and sudden death2. Myocardial ischemia-reperfusion injury (MIRI) is a complex cardiovascular condition influenced by factors such as cytokines, chemokines, growth factors, oxidative stress, and calcium overload3. Mitigating MIRI remains a significant challenge.
Recently, disulfideptosis has emerged as a novel form of cell death characterized by rapid collapse of the cytoskeletal actin network due to excessive accumulation of disulfides, including cysteine, within cells, resulting from NADPH+ depletion. Excessive disulfide accumulation disrupts disulfide bonds among cytoskeletal proteins, leading to actin migration and cell death4,5. Unlike previously reported forms of cell death such as apoptosis, necrosis, pyroptosis, and ferroptosis, disulfideptosis is initiated by the excessive aggregation of intracellular disulfides and is not antagonized by specific inhibitors of other cell death pathways. As a distinctive cell death, evidence has indicated that cellular glucose deficiency-evoked SLC7A11-overexpressing can trigger disulfidptosis4. After MIRI, insufficient insulin secretion can induce hypoglycemia and subsequent disulfidptosis, which may cause further damage to myocardial cells and may be one of the novel mechanisms of MIRI5.
In this study, the primary objective was to utilize comprehensive gene expression databases, such as the Gene Expression Omnibus (GEO), to analyze differential gene expression between normal and MIRI samples. We conducted a cross-referential analysis between differentially expressed genes and genes associated with disulfideptosis, with the aim of identifying disulfideptosis-related genes (DRGs) that exhibit differential expression in MIRI. Machine learning algorithms were employed to identify key genes, and we validated the expression patterns of the selected differential genes of interest using an animal model. This approach provides a fresh perspective towards gaining a deeper understanding of the potential mechanisms underlying the onset and progression of MIRI. The primary focus of this research was to investigate a novel cell death mechanism within MIRI, uncover associated differential genes, and conduct preliminary experiments to validate these findings. The ultimate goal was to identify novel therapeutic targets for mitigating MIRI based on this emerging cell death mechanism.
For this study, nine Sprague-Dawley (SD) male rats, aged 6-8 weeks and weighing 180-220 g, were selected from the Hubei Experimental Animal Research Center [SCXK (Hubei) 20200018]. Rats were kept in specific pathogen free animal houses to acclimatize for 1 week, with a 12 h/12 h light and dark cycle, free drinking and eating. The current study was conducted with approval from the Animal Ethics Committee of The Third Affiliated Hospital of Zunyi Medical University (approval number: (2016)-1-56). All procedures were performed in accordance with the recommendations outlined in the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health. Stringent measures were implemented to minimize the number of animals used and to mitigate their suffering.
1. Differential expression analysis of genes related to MIRI and disulfideptosis
NOTE: RNA sequencing data from MIRI named GSE214122 were selected to screen genes associated with disulfideptosis according to literature report6.
2. Construction of the rat MIRI model
3. Harvest heart tissue3
4. Hematoxylin-eosin (H&E) staining
5. TUNEL assay
6. Immunohistochemical staining
7. Western blot detection
NOTE: Lysis buffer and protease inhibitor were included in a BCA protein quantification kit (see Table of Materials).
8. Statistical analysis
Screening of DRGs in MIRI
The GSE214122 dataset from Gene Expression Omnibus included three sham and three MIRI samples data. Using the DESeq2 package in R, 1233 differentially expressed genes (DEGs) were identified between MIRI and sham samples. Based on |log2FC|>2 and FDR<0.05, 417 significantly different genes were further selected using R's pheatmap package (Figure 1A). Then, 15 intersection genes between these 1233 DEGs and 106 DRGs were presented in Figure 1B. The 15 differentially expressed DRGs were further annotated by a volcano plot, with 12 DRGs being labeled on the volcano map, as depicted in Figure 1C. A PPI network for the 15 DRGs was then constructed using STRING with three genes in the network being not connected and consequently removed. The final PPI network comprised 12 genes, as illustrated in Figure 1D.
MIRI promotes rat myocardial cell damage
HE staining results demonstrated that in control (no surgical procedures) and sham (with the same surgical procedures as the model group but no ischemia-reperfusion procedures) groups, myocardial cells exhibited regular morphology, well-organized myocardial fibers, and no evident signs of edema or inflammatory cell infiltration. In contrast, the model group exhibited disorganized myocardial cell arrangement, swelling, reduced cell count, myocardial fiber fragmentation, and noticeable infiltration of foamy cells and a large number of inflammatory cells (Figure 2A).
TUNEL staining results revealed that, in comparison to the control and sham groups, the model group exhibited a significant increase in red fluorescent-labeled apoptotic cells within rat myocardial tissues (Figure 2B). The apoptosis rate was markedly elevated (Figure 2C, p < 0.01) in the model group, with no statistically significant differences observed between the control and sham groups.
Expression of F-actin and GLUT1 in rat myocardial tissue of MIRI
Compared to the control and sham groups, the model group exhibited a significant increase in GLUT1 expression (Figure 3A,B, p < 0.01) and a significant decrease in F-actin expression (Figure 3C,D, p < 0.01). No significant differences were observed between the control and sham groups for GLUT1 and F-actin protein expression.
Expression of Myh9, SLC7A11, and SLC3A2 in rat myocardial tissue of MIRI
Immunohistochemical analysis was first employed to assess expression levels of DRGs in the rat MIRI model. The results showed that, in comparison to the control and sham groups, the model group had significantly increased expression levels of Myh9 (Figure 4A,B, p < 0.01) and SLC3A2 (Figure 4E,F, p < 0.01). In contrast, the expression of SLC7A11 was significantly reduced (Figure 4C,D, p < 0.01). Conformably, the results of western blotting showed that, in comparison to the control and sham groups, the model group had significantly increased expression levels of Myh9 (Figure 5A,B, p < 0.01) and SLC3A2 (Figure 5A,D, p < 0.01) while the expression of SLC7A11 (Figure 5A,C, p < 0.01) was significantly reduced.
Figure 1: Screening of disulfideptosis-related genes in MIRI. (A) Heatmap of 1233 genes for differential expression analysis on MIRI and sham samples. (B) Venn diagram of DEGs and DRGs. There were 15 common genes among the 1233 DEGs and 99 DRGs, as shown in the box. (C) Volcano plots of DEGs in the GSE214122 dataset. Red and green dots on the plot, respectively, indicate upregulated and downregulated genes. (D) PPI network of the 12 hub DRGs was constructed using the STRING database. DEGs, differentially expressed genes; DRGs, disulfideptosis-related genes. Please click here to view a larger version of this figure.
Figure 2: MIRI promotes myocardial cell damage. (A) Representative images of the myocardial injuries evaluated by H&E staining (scale bar = 50 µm). (B) Apoptosis of cardiomyocytes detected by TUNEL assay. The model group exhibited a significant increase in red fluorescent-labeled apoptotic cells within rat myocardial tissues (scale bar = 50 µm). (C) The statistical results of apoptosis rate by analysing the red fluorescence signal intensity using Image J software. **p < 0.01, the model group vs. the sham group, n=3. Data is expressed as the mean ± standard deviation. Please click here to view a larger version of this figure.
Figure 3: Expression of F-actin and GLUT1 in myocardial tissue of rat MIRI. (A) IHC staining of GLUT1 and (B) statistical results of its protein expression. (C) IHC staining of F-actin and (D) statistical results of its protein expression. scale bar = 50 µm. **p < 0.01, the model group vs. the sham group, n=6. Data is expressed as the mean ± standard deviation. Please click here to view a larger version of this figure.
Figure 4: IHC staining analysis of the expression of disulfideptosis-related proteins Myh9, SLC7A11, and SLC3A2 in myocardial tissue of rat MIRI. (A) IHC staining of Myh9 and (B) statistical results of its protein expression. (C) IHC staining of SLC7A11 and (D) statistical results of its protein expression. (E) IHC staining of SLC3A2 and (F) statistical results of its protein expression. scale bar = 50 µm. **p < 0.01, the model group vs. the sham group, n=3. Data is expressed as the mean ± standard deviation. Please click here to view a larger version of this figure.
Figure 5: Western blot analysis of the expression of disulfideptosis-related proteins Myh9, SLC7A11, and SLC3A2 in myocardial tissue of rat MIRI. (A) Representative protein bands. Statistical results of (B) Myh9, (C) SLC7A11, and (D) SLC3A2 protein expression. **p < 0.01, the model group vs. the sham group, n=3. The grayscale values of the proteins were analyzed using Image J software. Data is expressed as the mean ± standard deviation. Please click here to view a larger version of this figure.
Disulfideptosis is closely associated with the actin cytoskeleton, a critical cellular structure essential for maintaining cell shape and viability. Composed of actin filaments, the actin cytoskeleton imparts overall cellular shape and structure. F-actin serves as a marker for the cellular cytoskeleton, and under conditions of glucose starvation, disulfide bonds increase significantly, leading to downregulation of F-actin. This phenomenon primarily affects processes and pathways related to the actin cytoskeleton and cell adhesion10,11.
In the context of glucose metabolism, glucose transporters (GLUTs) play a vital role in maintaining the dynamic balance of glucose. GLUT1, one of the earliest-discovered members of the GLUT family, is a glucose uptake-related protein with widespread tissue distribution. It is primarily expressed in red blood cells12 and endothelial cells of the blood-brain barrier13, where it participates in the transmembrane transport of glucose. GLUT1 may be closely related to the development of diseases associated with abnormal glucose metabolism. In glucose-starvation models, GLUT1 expression is upregulated, promoting tumor cell death. In the MIRI model, upregulation of GLUT1 expression worsens MIRI, but improvements are observed when GLUT1 is downregulated, making it a key target under glucose starvation14. Immunohistochemistry revealed a significant intracellular increase in the glucose transporter protein GLUT1 in the MIRI model compared to the control and sham groups. At the same time, F-actin was significantly decreased intracellularly compared to the control and sham groups. This suggests that the collapse of the actin cytoskeleton under glucose starvation conditions may contribute to the worsening of MIRI, making the collapse of the actin cytoskeleton the primary mechanism of disulfideptosis. Therefore, we speculate that the upregulation of GLUT1 in the MIRI model induces disulfideptosis, leading to aggravated ischemia-reperfusion injury.
The Myh9 gene encodes the heavy chain of non-muscle myosin IIA, a widely expressed cytoplasmic myosin involved in various processes requiring the generation of intracellular mechanical forces and actin cytoskeletal repositioning15. Patients with congenital thrombocytopenia due to Myh9 gene mutations are prone to thrombus formation and acute myocardial infarction16. Therefore, Myh9 may be a predictive factor for AMI or MIRI. SLC7A11 and SLC3A2 are proteins that assist cells in obtaining cysteine and glutathione, which are essential for maintaining cell health and balance. SLC7A11 can mitigate lipid peroxidation and oxidative stress to play a protective role in MIRI17. Our study explored the potential biological functions and therapeutic significance of genes related to disulfideptosis through the GEO database. We found a limited overlap between MIRI and disulfideptosis-related genes, with a total of 12 overlapping genes. Through P-value and Log2Fold Change analysis, we identified four genes that were most closely related in the MIRI model. The results indicated significant upregulation of Myh9 expression and significant downregulation of SLC7A11 expression in the MIRI group. However, no statistically significant difference was observed in ACTB expression. The experimental results confirmed that Myh9 and SLC7A11 are involved in MIRI, and their mechanisms may be closely related to disulfideptosis mediated by NADPH depletion. These findings provide important clues for identifying new predictive factors and personalized treatment strategies for MIRI (Figure 5).
In summary, the identification and characterization of cell death mechanisms not only promote our fundamental understanding of cellular homeostasis but also highlight the significant role played by disulfideptosis in MIRI. The shortcoming of this method is the lack of critical validation experiments for disulfideptosis. Currently, it is possible to detect and identify disulfideptosis using the fluorescent probe DCP-Bio1, which binds to disulfide bonds, labeling intracellular and extracellular disulfides and facilitating the observation of disulfides in cells or tissues18. Such novel probes can be employed to study the spatiotemporal dynamics between disulfideptosis and MIRI.
The authors have nothing to disclose.
This research was supported by the Guizhou Provincial Bureau of Science and Technology (Qiankehe [2022]-583) and the Guizhou Provincial Administration of Traditional Chinese Medicine (QZYY-2016-019).
Name | Company | Catalog Number | Comments |
75% alcohol | Hunan Tongruijian Pharmaceutical Co. Ltd., Hunan, China | 85026 | |
6-0 nylon suture | Shanghai Pudong Jinhuan Medical Supplies Co. Ltd., Shanghai, China | CS002 | |
BCA protein quantification kit | Beyotime Biotechnology, Shanghai, China | P0011 | |
Bull serum albumin | Beyotime Biotechnology, Shanghai, China | ST2254 | |
Centrifuge | Hunan Kaida Scientific Instrument Co. Ltd., Hunan, China | KH19A | |
DAB horseradish peroxidase color development kit | Beyotime Biotechnology, Shanghai, China | P0203 | |
DAPI staining solution | Beyotime Biotechnology, Shanghai, China | C1006 | |
DESeq2 package | Version 4.1 | ||
Electric razor | Kelmerpp | 235376 | |
Enhanced endogenous peroxidase blocking buffer | Beyotime Biotechnology, Shanghai, China | P0100B | |
Filter paper | Nanjing Keruicai Equipment Co., Ltd., Nanjing, China | 1.00049E+11 | |
Fluorescence microscope | Nikon | ECLIPSE Ci | |
GEO database | https://www.ncbi.nlm.nih.gov/geo/ | ||
Glass grinder | Shanghai Leigu Instrument Co. Ltd., Shanghai, China | B-013002 | |
GraphPad Prism | GraphPad Software | V8.0 | |
Hematoxylin and eosin staining kit | Beyotime Biotechnology, Shanghai, China | C0105M | |
Image J software | National Institutes of Health, Bethesda, USA | v1.8.0 | |
Improved citrate antigen retrieval solution (50X) | Beyotime Biotechnology, Shanghai, China | P0083 | |
Iodophor | Folca, Shenzhen, China | 1.00077E+11 | |
Optical microscope | Nikon | ECLIPSE Ci | |
Phosphate buffer solution | Beyotime Biotechnology, Shanghai, China | C0221A | |
Primary antibodies against GLUT1 | Proteintech Group, Inc, Wuhan, China | 21829-1-AP | |
Primary antibodies against MYH9 | Proteintech Group, Inc, Wuhan, China | 11128-1-AP | |
Primary antibodies against SLC3A2 | Wuhan Lingsi Biotechnology Co., Ltd., Wuhan, China | LJS-D-7468 | |
Primary antibodies against SLC7A11 | Proteintech Group, Inc, Wuhan, China | 26864-1-AP | |
Protein visualization instrument | Thermo Fisher Scientific Inc. | iBright CL750 | |
Rat board | Zhengzhou Haopai Biotechnology Co. Ltd., Zhengzhou, China | JPB-E | |
Scalpel | Shanghai Lianhui Medical Supplies Co., Ltd., Shanghai, China | 1.00471E+13 | |
Secondary antibody | Wuhan Boster Biological Technology, Ltd., Wuhan, China | BA1054 | |
STRING database | https://cn.string-db.org/ | Version 12.0 | |
Triton X-100 | Beyotime Biotechnology, Shanghai, China | ST1722 | |
TUNEL apoptosis detection kit | Proteintech Group, Inc., Wuhan, China | PF00009 |
Request permission to reuse the text or figures of this JoVE article
Request PermissionThis article has been published
Video Coming Soon
Copyright © 2025 MyJoVE Corporation. All rights reserved