Establishment of a Mitochondrial Metabolism-Related Diagnostic Model in Schizophrenia Based on LASSO Algorithm

Article information

Psychiatry Investig. 2024;21(6):618-628
Publication date (electronic) : 2024 June 24
doi : https://doi.org/10.30773/pi.2024.0011
1Department of Pharmacy, The Third Hospital of Longyan, Longyan, China
2Department of Pharmacy, The First Hospital of Longyan, Longyan, China
3Department of Laboratory Medicine, The Third Hospital of Longyan, Longyan, China
Correspondence: Yaohui Wen Department of Laboratory Medicine, The Third Hospital of Longyan, NO.4 Baozhu South Road, Longyan, Fujian Province, 364000, China Tel: +86-13605911389, E-mail: wenyhuii@163.com
Received 2024 January 11; Revised 2024 March 18; Accepted 2024 March 25.

Abstract

Objective

Schizophrenia is a common mental disorder, and mitochondrial function represents a potential therapeutic target for psychiatric diseases. The role of mitochondrial metabolism-related genes (MRGs) in the diagnosis of schizophrenia remains unknown. This study aimed to identify candidate genes that may influence the diagnosis and treatment of schizophrenia based on MRGs.

Methods

Three schizophrenia datasets were obtained from the Gene Expression Omnibus database. MRGs were collected from relevant literature. The differentially expressed genes between normal samples and schizophrenia samples were screened using the limma package. Venn analysis was performed to identify differentially expressed MRGs (DEMRGs) in schizophrenia. Based on the STRING database, hub genes in DEMRGs were identified using the MCODE algorithm in Cytoscape. A diagnostic model containing hub genes was constructed using LASSO regression and logistic regression analysis. The relationship between hub genes and drug sensitivity was explored using the DSigDB database. An interaction network between miRNA-transcription factor (TF)-hub genes was created using the Network-Analyst website.

Results

A total of 1,234 MRGs, 172 DEMRGs, and 6 hub genes with good diagnostic performance were identified. Ten potential candidate drugs (rifampicin, fulvestrant, pentadecafluorooctanoic acid, etc.) were selected. Thirty-four miRNAs targeting genes in the diagnostic model (ANGPTL4, CPT2, GLUD1, MED1, and MED20), as well as 137 TFs, were identified.

Conclusion

Six potential candidate genes showed promising diagnostic significance. rifampicin, fulvestrant, and pentadecafluorooctanoic acid were potential drugs for future research in the treatment of schizophrenia. These findings provided valuable evidence for the understanding of schizophrenia pathogenesis, diagnosis, and drug treatment.

INTRODUCTION

Schizophrenia is a mentally debilitating disorder with unknown etiology that primarily affects young adults between the ages of 16 and 30 and often persists throughout their lives [1]. Current research suggests that schizophrenia is associated with biological factors such as genetics, abnormal neural development, and neurotransmitter abnormalities, as well as psychosocial factors including personality, mental endurance, and stress [2-5]. Clinical observations indicate that patients with different subtypes of schizophrenia exhibit varying symptoms, which are complex and diverse. These symptoms often involve impairments in perception, thinking, emotion, volition, behavior, and cognitive functions. Furthermore, there are significant inter-individual differences in symptom presentation, and even within the same patient, different symptoms may manifest during different stages or phases of the illness [6-8]. Therefore, early detection and treatment are crucial in managing schizophrenia [9]. Currently, pharmacological and psychological therapies have shown some efficacy in improving the recovery rate of individuals with schizophrenia [10]. However, the underlying causes of schizophrenia remain incompletely understood [11]. Therefore, exploring various factors that may influence the occurrence and development of schizophrenia could contribute to the diagnosis and treatment of the disorder.

Mitochondria are the primary producers of cellular energy and play a crucial regulatory role in iron homeostasis, amino acid metabolism, and nucleotide synthesis [12-15]. In recent years, numerous studies have demonstrated the significant involvement of mitochondria in brain development and the pathogenesis of various mental disorders [16]. In the central nervous system, mitochondria generate membrane ATPases and provide abundant energy to support the influx and efflux of neurotransmitters. They also participate in synaptic transmission, neuronal growth, and sprouting [17]. Schizophrenia has been associated with impaired immune function, abnormal neuronal differentiation, and various neurotransmitter system abnormalities [18]. Therefore, investigating the relationship between mitochondria and schizophrenia is of great research significance. With the advancement of studies, researchers have increasingly focused on the role of mitochondria in the pathophysiology of schizophrenia [19,20]. Ni et al. [21] found that enhancing mitochondrial function can serve as a potential therapeutic target for psychiatric disorders. However, the role of mitochondrial metabolism-related genes (MRGs) in the diagnosis of schizophrenia remains unknown.

In this study, we downloaded three schizophrenia expression datasets from the Gene Expression Omnibus (GEO) database and obtained MRGs from relevant literature. Differential analysis and Venn analysis were performed to identify differentially expressed MRGs (DEMRGs) in schizophrenia. Subsequently, hub genes were selected from the DEMRGs, and a diagnostic model was constructed to identify key genes with diagnostic value. Additionally, candidate drugs potentially targeting hub genes were predicted, and potential miRNAs and transcription factors (TFs) were screened. Overall, this study not only predicted multiple diagnostic biomarkers for schizophrenia but also provided new insights for further research on miRNAs, TFs, and candidate drugs targeting MRGs.

METHODS

Data retrieval

Three expression datasets related to schizophrenia were downloaded from the GEO database: GSE21138 (normal: 29, disease: 30), GSE92538 (normal: 50, disease: 24), and GSE27383 (normal: 29, disease: 43). A total of 1,234 MRGs (Supplementary Table 1 in the online-only Data Supplement) were obtained from the previously published literature [22].

Identification and enrichment analysis of MRGs in schizophrenia

In the GSE21138 dataset, differentially expressed genes (DEGs) between normal and schizophrenia samples were screened using the limma package, with a threshold of p-value <0.05 and |LogFC| >0.1. The intersection between DEGs and MRGs was obtained through Venn analysis, resulting in the identification of DEMRGs specific to schizophrenia. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of DEMRGs were performed using the clusterProfiler R package [23] to explore their potential functions.

Identification of hub genes in DEMRGs

The DEMRGs were input into the STRING database (https://string-db.org/) to construct a protein-protein interaction (PPI) network with a confidence score >0.4. The hub genes in DEMRGs were identified using the MCODE algorithm in the cytoHubba plugin of Cytoscape software [24], based on the PPI network data obtained from the STRING database.

Construction and validation of the diagnostic model based on hub genes

The LASSO model was established using the gene expression profiles of hub genes based on the glmnet R package. The minimum lambda value was used as a reference to determine the optimal variables to be included in the model. A logistic regression analysis was performed using the genes obtained from the LASSO model to construct a model formula that included the hub gene expression values and regression coefficients. The specific formula was as follows:

Index= Coef1×ExpGene1+Coef2×ExpGene2+Coef3×ExpGene3+…+CoefN×ExpGeneN.

Receiver operating characteristic curve (ROC) curves were plotted using the pROC R package in each of the three datasets (GSE21138, GSE92538, and GSE27383) to evaluate the stability and sensitivity of the LASSO model. Additionally, ROC curves of hub genes were plotted in the three datasets to assess the accuracy of hub genes in diagnosing the disease.

Prediction of potential drugs

The online network tool Enrichr (https://maayanlab.cloud/Enrichr/) was used to explore the relationship between hub genes and drug sensitivity through access to the DSigDB database. The CellMiner database (https://discover.nci.nih.gov/cellminer/home.do) is a molecular and pharmacological database of 60 cell lines based on the National Cancer Institute, which contains transcriptome data for 60 cell lines and more than 100,000 natural products and compounds. Drugs approved by the U.S. Food and Drug Administration and drugs in clinical trials were selected for in-depth analysis. Then Spearman correlation analysis was conducted to determine the correlation between hub genes and drug sensitivity.

Construction of a miRNA-TF-hub gene network

The NetworkAnalyst website (https://www.networkanalyst.ca/) was used to create an interaction network between miRNA-TF-hub genes. The following parameters were specified: organism: Homo sapiens (human), collection ID type: official gene symbol, gene-miRNA interaction database: miRTarBase v8.0, and gene-TF interaction database: ENCODE.

RESULTS

Identification and analysis of DEMRGs

Through differential expression analysis, a total of 2,582 DEGs were identified in the GSE21138 dataset (Figure 1A). By conducting Venn analysis, we obtained 172 DEMRGs (Figure 1B). The results of enrichment analysis showed that DEMRGs were enriched in GO terms such as phospholipid metabolic process, phospholipid biosynthetic process, mitochondrial matrix, tricarboxylic acid cycle enzyme complex, and phosphatidylinositol phosphate phosphatase activity (Figure 1C). Furthermore, they were also found to be enriched in KEGG pathways including Carbon metabolism, peroxisome proliferator-activated receptor signaling pathway, citrate cycle (tricarboxylic acid cycle), phosphatidylinositol signaling system, biosynthesis of amino acids, alanine, aspartate and glutamate metabolism, tryptophan metabolism, and fatty acid degradation (Figure 1D).

Figure 1.

Identification of DEMRGs and pathway enrichment analysis. A: Volcano plot of DEGs between schizophrenia samples and normal samples in GSE21138. B: Venn diagram of DEGs and MRGs in GSE21138. C: GO enrichment analysis of DEMRGs. D: KEGG enrichment analysis of DEMRGs. DEGs, differentially expressed genes; MRGs, mitochondrial metabolism-related genes; DEMRGs, differentially expressed MRGs; GO, Gene Ontology.

Selection of hub genes in DEMRGs

Using the STRING database, we constructed a PPI network of interactions among genes in DEMRGs. The results revealed complex interactions among most of the genes (Figure 2A). Furthermore, using the MCODE algorithm in the cytoHubba plugin, we identified 18 hub genes from the DEMRGs (Figure 2B).

Figure 2.

Filter Hub gene in DEMRGs. A: PPI network of DEMRGs. B: Hub genes selected by the MCODE algorithm in the cytoHubba plugin. PPI, protein-protein interaction; DEMRGs, differentially expressed MRGs.

Diagnostic model construction based on hub genes and model validation

Furthermore, using the MCODE algorithm, 18 hub genes selected were used to construct a LASSO logistic regression diagnostic model. The minimum lambda value was used as a reference during the process to determine the optimal variables to be included in the model. Eventually, six diagnostic model genes (ANGPTL4, CPT2, GLUD1, MED1, MED13L, and MED20) were identified (Figure 3A). The model formula was as follows:

Figure 3.

Construction and validation of the diagnostic model. A: LASSO regression analysis determining the optimal variable for the diagnostic model. B: ROC curves plotted in GSE21138, GSE92538, and GSE27383. ROC, receiver operating characteristic curve; AUC, area under curve; TP, true positive; FP, false positive.

Index=0.1417×ANGPTL4+0.2044×CPT2+0.3251×GLU D1+0.2990×MED1+0.6585×MED13L-0.7082×MED20.

Afterwards, the ROC curves of the model were plotted using the pROC R package in three datasets (GSE21138, GSE92538, and GSE27383). The results showed that the area under curve (AUC) values of the ROC curves in all three datasets were greater than 0.62, indicating that the diagnostic model constructed based on the six genes had good stability and sensitivity (Figure 3B). In addition, the evaluation of the diagnostic performance of the six individual genes revealed the following AUC values in GSE21138: 0.695 for ANGPTL4, 0.692 for CPT2, 0.714 for GLUD1, 0.685 for MED1, 0.738 for MED13L, and 0.692 for MED20 (Figure 4A); in GSE92538: 0.646 for ANGPTL4, 0.531 for CPT2, 0.571 for GLUD1, 0.67 for MED1, 0.631 for MED13L, and 0.595 for MED20 (Figure 4B); and in GSE27383: 0.499 for ANGPTL4, 0.493 for CPT2, 0.522 for GLUD1, 0.542 for MED1, 0.613 for MED13L, and 0.617 for MED20 (Figure 4C). These analyses collectively indicated that both the diagnostic model constructed using the six genes and the individual genes themselves exhibited good diagnostic performance.

Figure 4.

Prediction of potential drugs. A: ROC curve analysis of the six genes in the diagnostic model in GSE21138. B: ROC curve analysis of the six genes in the diagnostic model in GSE92538. C: ROC curve analysis of the six genes in the diagnostic model in GSE27383. ROC, receiver operating characteristic curve.

Prediction of potential drugs

After screening using DSigDB, we obtained ten potential candidate drugs: rifampicin, fulvestrant, pentadecafluorooctanoic acid, eldecalcitol, aluminum chloride, digoxin, 2,2'-bipyridine, tesaglitazar, perfluoroundecanoic acid, and alfacalcidol (Figure 5A). Furthermore, the prediction results of the gene-drug interaction network showed that rifampicin may be associated with ANGPTL4 and MED1, fulvestrant with MED13L and MED1, pentadecafluorooctanoic acid with CPT2 and ANGPTL4, eldecalcitol with MED1, aluminum chloride with GLUD1, digoxin with MED13L and MED1, 2,2'-bipyridine with ANGPTL4, tesaglitazar with CPT2, and perfluoroundecanoic acid and GW0742 with ANGPTL4 (Figure 5B).

Figure 5.

Construction of the miRNA-TF-gene interaction network. A: Top ten ranked drugs predicted by DSigDB. B: Gene-drug interaction network predicted by DSigDB. TF, transcription factor.

To further explore the clinical value of hub genes, we used CellMiner database to explore the correlation between hub genes and drug sensitivity. ANGPTL4 was correlated significantly and negatively with nilotinib, BP-102, vincristine, desfluoro-TAK-960, lexibulin, and OSU-03012. CPT2 was correlated significantly and negatively with dasatinib. MED13L was correlated significantly and negatively with vinorelbine. MED1 was correlated significantly and negatively with alectinib (Figure 6).

Figure 6.

Scatter plot of relationship between model genes expression and drug sensitivity. The horizontal axis represents the gene expression. The vertical axis represents the IC50 values.

Construction of the miRNA-TF-gene interaction network

Through analysis, we identified a total of 34 miRNAs that potentially targeted and regulated the diagnostic model genes (ANGPTL4, CPT2, GLUD1, MED1, and MED20), as well as 137 TFs. Noteworthily, the TF SMAD5 may simultaneously interact with all five genes (ANGPTL4, CPT2, GLUD1, MED1, and MED20) (Figure 7).

Figure 7.

The network diagram of the miRNA-TF-gene interactions. The red circles represent mRNAs, the blue diamonds represent miRNAs, and the green pentagons represent TFs. TF, transcription factor.

DISCUSSION

Schizophrenia is a complex mental disorder with its etiology involving neurochemical and neurodevelopmental components [25]. Increasing evidence suggests that individuals with schizophrenia exhibit multifaceted mitochondrial dysfunctions [26,27]. For instance, a study by Beeraka et al. [28] revealed that mitochondrial DNA alterations, Nrf2 signaling pathway, dynamic changes in the dorsolateral prefrontal cortex, and oxidative stress activation contribute to the progression of schizophrenia [28]. Furthermore, it has been found that impaired cellular function, neuroplasticity, and disruption of brain circuits in individuals with schizophrenia may be attributed to compromised energy metabolism and increased oxidative stress, primarily regulated by mitochondria [17,29,30]. The aim of this study was to further explore the relationship between MRGs and schizophrenia, develop valuable diagnostic biomarkers and potential therapeutic targets for schizophrenia, and provide insights for future research in the diagnosis and treatment of individuals with schizophrenia.

Several biological processes, such as phospholipid biosynthetic process, phospholipid metabolic process, biosynthesis of amino acids, and alanine, aspartate, and glutamate metabolism, were found to be enriched among the identified DEMRGs in this study. Previous research has implicated disturbances in phospholipid metabolism in the pathogenesis of schizophrenia. Wang et al. [31], using untargeted liquid chromatography-mass spectrometry metabolomics, found differential expression of multiple phospholipids (phosphatidylcholines, lysophosphatidylcholines, phosphatidylethanolamines, lysophosphatidylethanolamines, and sphingomyelins) in individuals with schizophrenia compared to healthy controls, suggesting their association with the development of schizophrenia. Alanine and glutamate are both important amino acids that have been shown to be closely related to schizophrenia. Clinical research by Hatano et al. [32] revealed a correlation between increased plasma levels of alanine from the acute phase to the remission phase of schizophrenia and improvement in symptoms, suggesting that endogenous plasma alanine levels could serve as clinical markers for the severity and improvement of schizophrenia. Additionally, recent studies have implicated glutamate-mediated neurotransmission dysfunction in various neuropsychiatric disorders, including schizophrenia [33]. Meta-analysis of glutamate proton magnetic resonance spectroscopy studies has shown an elevation of glutamate metabolites in multiple brain regions in schizophrenia, suggesting that compounds that reduce glutamate transmission may hold therapeutic potential [34]. Taken together, these findings suggest that DEMRGs may regulate the disease progression of individuals with schizophrenia by modulating these biological processes.

ANGPTL4, CPT2, GLUD1, MED1, MED13L, and MED20 were identified as diagnostic biomarkers with diagnostic value in this study. Mediator complex (MED) is a large, evolutionarily conserved multi-protein complex that facilitates the interaction between TFs and RNA polymerase II in eukaryotes, and some MED subunits (such as MED13L, MED1, and MED20) have been found to undergo changes in the brain. Among them, MED13L and MED20 are associated with various genetic diseases, while MED1 is involved in post-stroke cognitive impairment [35]. Although the relationship between MED13L, MED1, MED20, and schizophrenia has not been discovered yet, research has found that MED1 is closely related to mitochondrial metabolism. Studies by Becerril et al. [36] and Li et al. [37] have shown that MED1 is involved in lipid synthesis, lipid metabolism, biosynthetic processes, glucose metabolism, and mitochondrial metabolic pathways. Enhancing MED1 can eliminate the promoting effect of miR-146a on lipid metabolism and mitochondrial function. ANGPTL4 is a secreted protein and an inhibitor of lipoprotein lipase-mediated plasma triglyceride clearance. It has been shown to be involved in the development of various diseases, including coronary artery disease, type 2 diabetes, and tumors [38-41]. Although the relationship between ANGPTL4 and schizophrenia has not been discovered yet, Wang et al. [42] found that many mitochondrial proteins are largely downregulated by ANGPTL4, and ANGPTL4 may induce its metabolic effects by regulating mitochondrial function and methionine. Carnitine palmitoyltransferase (CPT) 2 is a mitochondrial fatty acid oxidation enzyme that is involved in the entry of long-chain fatty acids into the mitochondria for β-oxidation and energy production [43,44]. Research by Virmani et al. [45] suggests that the activity of the CPT system (CPT1 and CPT2) is associated with Parkinson’s disease, Alzheimer’s disease, and schizophrenia, mainly related to changes in insulin balance in the brain. GLUD1 in the central nervous system is a crucial metabolic enzyme in glutamate metabolism and can lead to behavioral abnormalities and increased mPFC glutamate in schizophrenia patients [46]. Research by Yadav et al. [47] found that the absence of GLUD1 leads to abnormal emotional and social behavior. Therefore, based on these analyses, we speculated that ANGPTL4, CPT2, GLUD1, MED1, MED13L, and MED20 may be key genes influencing the progression of schizophrenia.

Through screening with DSigDB, we obtained ten potential candidate drugs: rifampicin, fulvestrant, pentadecafluorooctanoic acid, eldecalcitol, aluminum chloride, digoxin, 2,2'-bipyridine, tesaglitazar, perfluoroundecanoic acid, and alfacalcidol. Gene and drug targeting predictions showed that rifampicin may be associated with ANGPTL4 and MED1; fulvestrant may be associated with MED13L and MED1; pentadecafluorooctanoic acid may be associated with CPT2 and ANGPTL4; eldecalcitol may be associated with MED1; aluminum chloride may be associated with GLUD1; digoxin may be associated with MED13L and MED1; 2,2'-bipyridine may be associated with ANGPTL4; tesaglitazar may be associated with CPT2; and perfluoroundecanoic acid and GW0742 may be associated with ANGPTL4. However, there is limited research on the relationship between these drugs and schizophrenia or their target genes. Therefore, further research is still needed in this area.

In conclusion, this study identified six MRGs (ANGPTL4, CPT2, GLUD1, MED1, MED13L, and MED20) with diagnostic significance for schizophrenia through bioinformatics analysis. Additionally, several miRNAs, TFs, and candidate drugs targeting MRGs were identified. These findings provide potential research directions for understanding the pathogenesis of schizophrenia and exploring the possible drugs. However, this study is limited by the lack of corresponding clinical research and experimental confirmation.

Supplementary Materials

The online-only Data Supplement is available with this article at https://doi.org/10.30773/pi.2024.0011.

Supplementary Table 1.

Collection of 1234 MRGs

pi-2024-0011-Supplementary-Table-1.pdf

Notes

Availability of Data and Material

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.

Conflicts of Interest

The authors have no potential conflicts of interest to disclose.

Author Contributions

Conceptualization: Yinfang Liu. Data curation: Han Lin, Meicen Liu. Formal analysis: Yinfang Liu. Funding acquisition: Han Lin. Investigation: Han Lin. Methodology: Yinfang Liu. Project administration: Yaohui Wen. Resources: Yaohui Wen. Software: Liping Lin. Supervision: Meicen Liu. Validation: Liping Lin, Yaohui Wen. Visualization: Meicen Liu. Writing—original draft: Yinfang Liu. Writing—review & editing: Liping Lin.

Funding Statement

Project supported by the joint foundation of Longyan, FuJian province, China (FLY2023CWS010162).

Acknowledgements

None

References

1. Mueser KT, McGurk SR. Schizophrenia. Lancet 2004;363:2063–2072.
2. Cheng W, Frei O, van der Meer D, Wang Y, O’Connell KS, Chu Y, et al. Genetic association between schizophrenia and cortical brain surface area and thickness. JAMA Psychiatry 2021;78:1020–1030.
3. Ross CA, Margolis RL, Reading SA, Pletnikov M, Coyle JT. Neurobiology of schizophrenia. Neuron 2006;52:139–153.
4. Mandal PK, Gaur S, Roy RG, Samkaria A, Ingole R, Goel A. Schizophrenia, bipolar and major depressive disorders: overview of clinical features, neurotransmitter alterations, pharmacological interventions, and impact of oxidative stress in the disease process. ACS Chem Neurosci 2022;13:2784–2802.
5. Stilo SA, Murray RM. Non-genetic factors in schizophrenia. Curr Psychiatry Rep 2019;21:100.
6. Ahmed AO, Strauss GP, Buchanan RW, Kirkpatrick B, Carpenter WT. Schizophrenia heterogeneity revisited: clinical, cognitive, and psychosocial correlates of statistically-derived negative symptoms subgroups. J Psychiatr Res 2018;97:8–15.
7. Chai C, Ding H, Du X, Xie Y, Man W, Zhang Y, et al. Dissociation between neuroanatomical and symptomatic subtypes in schizophrenia. Eur Psychiatry 2023;66:e78.
8. Fervaha G, Agid O, Foussias G, Siddiqui I, Takeuchi H, Remington G. Neurocognitive impairment in the deficit subtype of schizophrenia. Eur Arch Psychiatry Clin Neurosci 2016;266:397–407.
9. Hasan A, Falkai P, Wobrock T. [Early detection and treatment of schizophrenia]. MMW Fortschr Med 2010;152:53–55. German.
10. Bighelli I, Rodolico A, García-Mieres H, Pitschel-Walz G, Hansen WP, Schneider-Thoma J, et al. Psychosocial and psychological interventions for relapse prevention in schizophrenia: a systematic review and network meta-analysis. Lancet Psychiatry 2021;8:969–980.
11. Sabaie H, Gharesouran J, Asadi MR, Farhang S, Ahangar NK, Brand S, et al. Downregulation of miR-185 is a common pathogenic event in 22q11.2 deletion syndrome-related and idiopathic schizophrenia. Metab Brain Dis 2022;37:1175–1184.
12. Vigani G, Zocchi G, Bashir K, Philippar K, Briat JF. Signals from chloroplasts and mitochondria for iron homeostasis regulation. Trends Plant Sci 2013;18:305–311.
13. Choudhury M, Fu T, Amoah K, Jun HI, Chan TW, Park S, et al. Widespread RNA hypoediting in schizophrenia and its relevance to mitochondrial function. Sci Adv 2023;9:eade9997.
14. Lv T, Xiong X, Yan W, Liu M, Xu H, He Q. Mitochondrial general control of amino acid synthesis 5 like 1 promotes nonalcoholic steatohepatitis development through ferroptosis-induced formation of neutrophil extracellular traps. Clin Transl Med 2023;13:e1325.
15. Richter-Dennerlein R, Dennerlein S, Rehling P. Integrating mitochondrial translation into the cellular context. Nat Rev Mol Cell Biol 2015;16:586–592.
16. Kim Y, Vadodaria KC, Lenkei Z, Kato T, Gage FH, Marchetto MC, et al. Mitochondria, metabolism, and redox mechanisms in psychiatric disorders. Antioxid Redox Signal 2019;31:275–317.
17. Fizíková I, Dragašek J, Račay P. Mitochondrial dysfunction, altered mitochondrial oxygen, and energy metabolism associated with the pathogenesis of schizophrenia. Int J Mol Sci 2023;24:7991.
18. Ben-Shachar D. Mitochondrial multifaceted dysfunction in schizophrenia; complex I as a possible pathological target. Schizophr Res 2017;187:3–10.
19. Whitehurst T, Howes O. The role of mitochondria in the pathophysiology of schizophrenia: a critical review of the evidence focusing on mitochondrial complex one. Neurosci Biobehav Rev 2022;132:449–464.
20. Konradi C, Öngür D. Role of mitochondria and energy metabolism in schizophrenia and psychotic disorders. Schizophr Res 2017;187:1–2.
21. Ni P, Ma Y, Chung S. Mitochondrial dysfunction in psychiatric disorders. Schizophr Res 2022 Sep 26 [Epub]. https://doi.org/10.1016/j.schres.2022.08.027.
22. Meng C, Sun Y, Liu G. Establishment of a prognostic model for ovarian cancer based on mitochondrial metabolism-related genes. Front Oncol 2023;13:1144430.
23. Wu T, Hu E, Xu S, Chen M, Guo P, Dai Z, et al. clusterProfiler 4.0: a universal enrichment tool for interpreting omics data. Innovation (Camb) 2021;2:100141.
24. Guo A, Gao B, Zhang M, Shi X, Jin W, Tian D. Bioinformatic identification of hub genes Myd88 and Ccl3 and TWS-119 as a potential agent for the treatment of massive cerebral infarction. Front Neurosci 2023;17:1171112.
25. Park C, Park SK. Molecular links between mitochondrial dysfunctions and schizophrenia. Mol Cells 2012;33:105–110.
26. Roberts RC. Mitochondrial dysfunction in schizophrenia: with a focus on postmortem studies. Mitochondrion 2021;56:91–101.
27. Gonçalves VF, Andreazza AC, Kennedy JL. Mitochondrial dysfunction in schizophrenia: an evolutionary perspective. Hum Genet 2015;134:13–21.
28. Beeraka NM, Avila-Rodriguez MF, Aliev G. Recent reports on redox stress-induced mitochondrial DNA variations, neuroglial interactions, and NMDA receptor system in pathophysiology of schizophrenia. Mol Neurobiol 2022;59:2472–2496.
29. Fišar Z. Biological hypotheses, risk factors, and biomarkers of schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2023;120:110626.
30. Duarte JMN, Xin L. Magnetic resonance spectroscopy in schizophrenia: evidence for glutamatergic dysfunction and impaired energy metabolism. Neurochem Res 2019;44:102–116.
31. Wang D, Cheng SL, Fei Q, Gu H, Raftery D, Cao B, et al. Metabolic profiling identifies phospholipids as potential serum biomarkers for schizophrenia. Psychiatry Res 2019;272:18–29.
32. Hatano T, Ohnuma T, Sakai Y, Shibata N, Maeshima H, Hanzawa R, et al. Plasma alanine levels increase in patients with schizophrenia as their clinical symptoms improve-results from the Juntendo University Schizophrenia Projects (JUSP). Psychiatry Res 2010;177:27–31.
33. Moghaddam B, Javitt D. From revolution to evolution: the glutamate hypothesis of schizophrenia and its implication for treatment. Neuropsychopharmacology 2012;37:4–15.
34. Merritt K, Egerton A, Kempton MJ, Taylor MJ, McGuire PK. Nature of glutamate alterations in schizophrenia: a meta-analysis of proton magnetic resonance spectroscopy studies. JAMA Psychiatry 2016;73:665–674.
35. Schiano C, Luongo L, Maione S, Napoli C. Mediator complex in neurological disease. Life Sci 2023;329:121986.
36. Becerril S, Rodríguez A, Catalán V, Sáinz N, Ramírez B, Gómez-Ambrosi J, et al. Transcriptional analysis of brown adipose tissue in leptin-deficient mice lacking inducible nitric oxide synthase: evidence of the role of Med1 in energy balance. Physiol Genomics 2012;44:678–688.
37. Li K, Zhao B, Wei D, Wang W, Cui Y, Qian L, et al. miR‑146a improves hepatic lipid and glucose metabolism by targeting MED1. Int J Mol Med 2020;45:543–555.
38. Okamoto H, Cavino K, Na E, Krumm E, Kim S, Stevis PE, et al. Angptl4 does not control hyperglucagonemia or α-cell hyperplasia following glucagon receptor inhibition. Proc Natl Acad Sci U S A 2017;114:2747–2752.
39. Aryal B, Price NL, Suarez Y, Fernández-Hernando C. ANGPTL4 in metabolic and cardiovascular disease. Trends Mol Med 2019;25:723–734.
40. Dewey FE, Gusarova V, O’Dushlaine C, Gottesman O, Trejos J, Hunt C, et al. Inactivating variants in ANGPTL4 and risk of coronary artery disease. N Engl J Med 2016;374:1123–1133.
41. Zheng X, Liu R, Zhou C, Yu H, Luo W, Zhu J, et al. ANGPTL4-mediated promotion of glycolysis facilitates the colonization of Fusobacterium nucleatum in colorectal cancer. Cancer Res 2021;81:6157–6170.
42. Wang Y, Lam KS, Lam JB, Lam MC, Leung PT, Zhou M, et al. Overexpression of angiopoietin-like protein 4 alters mitochondria activities and modulates methionine metabolic cycle in the liver tissues of db/db diabetic mice. Mol Endocrinol 2007;21:972–986.
43. Jiang N, Xie B, Xiao W, Fan M, Xu S, Duan Y, et al. Fatty acid oxidation fuels glioblastoma radioresistance with CD47-mediated immune evasion. Nat Commun 2022;13:1511.
44. Aires V, Delmas D, Djouadi F, Bastin J, Cherkaoui-Malki M, Latruffe N. Resveratrol-induced changes in MicroRNA expression in primary human fibroblasts harboring carnitine-palmitoyl transferase-2 gene mutation, leading to fatty acid oxidation deficiency. Molecules 2017;23:7.
45. Virmani A, Pinto L, Bauermann O, Zerelli S, Diedenhofen A, Binienda ZK, et al. The carnitine palmitoyl transferase (CPT) system and possible relevance for neuropsychiatric and neurological conditions. Mol Neurobiol 2015;52:826–836.
46. Asraf K, Zaidan H, Natoor B, Gaisler-Salomon I. Synergistic, long-term effects of glutamate dehydrogenase 1 deficiency and mild stress on cognitive function and mPFC gene and miRNA expression. Transl Psychiatry 2023;13:248.
47. Yadav R, Gupta SC, Hillman BG, Bhatt JM, Stairs DJ, Dravid SM. Deletion of glutamate delta-1 receptor in mouse leads to aberrant emotional and social behaviors. PLoS One 2012;7:e32969.

Article information Continued

Figure 1.

Identification of DEMRGs and pathway enrichment analysis. A: Volcano plot of DEGs between schizophrenia samples and normal samples in GSE21138. B: Venn diagram of DEGs and MRGs in GSE21138. C: GO enrichment analysis of DEMRGs. D: KEGG enrichment analysis of DEMRGs. DEGs, differentially expressed genes; MRGs, mitochondrial metabolism-related genes; DEMRGs, differentially expressed MRGs; GO, Gene Ontology.

Figure 2.

Filter Hub gene in DEMRGs. A: PPI network of DEMRGs. B: Hub genes selected by the MCODE algorithm in the cytoHubba plugin. PPI, protein-protein interaction; DEMRGs, differentially expressed MRGs.

Figure 3.

Construction and validation of the diagnostic model. A: LASSO regression analysis determining the optimal variable for the diagnostic model. B: ROC curves plotted in GSE21138, GSE92538, and GSE27383. ROC, receiver operating characteristic curve; AUC, area under curve; TP, true positive; FP, false positive.

Figure 4.

Prediction of potential drugs. A: ROC curve analysis of the six genes in the diagnostic model in GSE21138. B: ROC curve analysis of the six genes in the diagnostic model in GSE92538. C: ROC curve analysis of the six genes in the diagnostic model in GSE27383. ROC, receiver operating characteristic curve.

Figure 5.

Construction of the miRNA-TF-gene interaction network. A: Top ten ranked drugs predicted by DSigDB. B: Gene-drug interaction network predicted by DSigDB. TF, transcription factor.

Figure 6.

Scatter plot of relationship between model genes expression and drug sensitivity. The horizontal axis represents the gene expression. The vertical axis represents the IC50 values.

Figure 7.

The network diagram of the miRNA-TF-gene interactions. The red circles represent mRNAs, the blue diamonds represent miRNAs, and the green pentagons represent TFs. TF, transcription factor.