Cystathionine γ-lyase inhibits mitochondrial oxidative stress by releasing H2S nearby through the AKT/NRF2 signaling pathway.

Cystathionine γ-lyase (CSE) is a major enzyme that produces hydrogen sulfide (H2S). Herein, we report how CSE plays a previously unknown role in regulating the antioxidant effects of the mitochondria in human umbilical vein endothelial cells by releasing H2S nearby under stress conditions. We found that H2S partially promoted angiogenesis in the endothelial cells through the AKT/nuclear factor erythroid 2-related factor 2 (AKT/NRF2) signaling pathway. H2S improved mitochondrial function by altering the expressions of the mitofusin2 and dynamin-1-like mitochondrial fission proteins to inhibit oxidative stress and enhance NRF2 nuclear translocation. CSE is located only in the cytoplasm and not in the mitochondria, but it is transported to the vicinity of the mitochondria to produce H2S, which plays an antioxidant role in human umbilical vein endothelial cells under stress. The CSE mutant (with mutated CSE activity center: CSED187A) partially decreased the effects on promoting angiogenesis, resisting oxidative stress, and entering the mitochondria. These results show that CSE translocation is a unique mechanism that promotes H2S production inside the mitochondria under stress stimulation. Therefore, the CSE mutant site (CSED187A) may be a potential target for drug therapy.

Step into the era of large multimodal models: a pilot study on ChatGPT-4V(ision)'s ability to interpret radiological images.

BACKGROUND: The introduction of ChatGPT-4V's 'Chat with images' feature represents the beginning of the era of large multimodal models (LMMs), which allows ChatGPT to process and answer questions based on uploaded images. This advancement has the potential to transform how surgical teams utilize radiographic data, as radiological interpretation is crucial for surgical planning and postoperative care. However, a comprehensive evaluation of ChatGPT-4V's capabilities in interpret radiological images and formulating treatment plans remains to be explored. PATIENTS AND METHODS: Three types of questions were collected: (1) 87 USMLE-style questions, submitting only the question stems and images without providing options to assess ChatGPT's diagnostic capability. For questions involving treatment plan formulations, a five-point Likert scale was used to assess ChatGPT's proposed treatment plan. The 87 questions were then adapted by removing detailed patient history to assess its contribution to diagnosis. The diagnostic performance of ChatGPT-4V was also tested when only medical history was provided. (2) We randomly selected 100 chest radiography from the ChestX-ray8 database to test the ability of ChatGPT-4V to identify abnormal chest radiography. (3) Cases from the 'Diagnose Please' section in the Radiology journal were collected to evaluate the performance of ChatGPT-4V in diagnosing complex cases. Three responses were collected for each question. RESULTS: ChatGPT-4V achieved a diagnostic accuracy of 77.01% for USMLE-style questions. The average score of ChatGPT-4V's treatment plans was 3.97 (Interquartile Range: 3.33-4.67). Removing detailed patient history dropped the diagnostic accuracy to 19.54% (P<0.0001). ChatGPT-4V achieved an AUC of 0.768 (95% CI: 0.684-0.851) in detecting abnormalities in chest radiography, but could not specify the exact disease due to the lack of detailed patient history. For cases from 'Diagnose Please' ChatGPT provided diagnoses consistent with or very similar to the reference answers. CONCLUSION: ChatGPT-4V demonstrated an impressive ability to combine patient history with radiological images to make diagnoses and directly design treatment plans based on images, suggesting its potential for future application in clinical practice.

Transcriptome analysis of effects of Tecrl deficiency on cardiometabolic and calcium regulation in cardiac tissue.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a hereditary heart disease characterized by bidirectional or polymorphic ventricular tachycardia and an increased risk of sudden cardiac death. Although trans-2,3-enoyl-CoA reductase like (TECRL) is a newly reported pathogenic gene leading to CPVT that can influence intracellular calcium regulation, the unidentified mechanism underlying the pathogenesis of TECRL deficiency-mediated CPVT remains mainly elusive. In the present study, Tecrl knockout (KO) mice were established and the differentially expressed genes (DEGs) were investigated by RNA-sequencing from the heart tissues. In addition, 857 DEGs were identified in Tecrl KO mice. Subsequently, a weighted gene co-expression network analysis was conducted to discern the pivotal pathways implicated in the Tecrl-mediated regulatory network. Moreover, pathway mapping analyses demonstrated that essential metabolism-related pathways were significantly enriched, notably the fatty acid metabolic process and calcium regulation. Collectively, the data suggested a synergistic relationship between Tecrl deficiency and cardiometabolic and calcium regulation during the development of CPVT. Therefore, further studies on the potential function of TECRL in cardiac tissues would be beneficial to elucidate the pathogenesis of CPVT.

Serum Metabolomic Profile in Hypoxia-Induced Pulmonary Hypertension Mice after C75 Treatment.

BACKGROUND: Inhibition of fatty acid synthase (FAS) plays a crucial protective role in pulmonary hypertension (PH). Our aim was to identify novel metabolites in mice with hypoxia-induced PH after treatment with C75 (FAS inhibitor) and to confirm the presence of these metabolites in paediatric patients with PH. METHODS: The PH mouse model was built by chronic hypoxia and ovalbumin (OVA) assistance. Untargeted metabolomics was used to analyse mouse serum. Six children with PH and six relative controls (patients without lung and heart disease) were selected in Shanghai Children's Hospital and they all performed blood tandem mass spectrometry during hospitalization. RESULTS: First, a total of 29 differential metabolites, including lipid metabolites, polyamine, and glutamine were identified as differential metabolites in the hypoxia group compared with the control group. After C75 treatment, symptoms were partially relieved in the PH mouse, and 15 differential metabolites, including lipid metabolites, polyamine, and glutamine were identified in the hypoxia + C75 group compared with the hypoxia group. These differential metabolites were enriched in arginine and glycerolipid metabolism through metabolite set enrichment analyses and were involved in excessive cell proliferation, which was a characteristic of PH. Second, glutamine and caproyl carnitine levels were increased in paediatric patients with PH. CONCLUSIONS: FAS may be a potential PH therapeutic target. Lipid metabolites, polyamine, and glutamine, are closely related to PH. Putrescine and glutamine might be biomarkers for PH.

The Emerging Role of Fatty Acid Synthase in Hypoxia-Induced Pulmonary Hypertensive Mouse Energy Metabolism.

AIMS: This study is aimed at examining whether fatty acid synthase (FAS) can regulate mitochondrial function in hypoxia-induced pulmonary arterial hypertension (PAH) and its related mechanism. RESULTS: The expression of FAS significantly increased in the lung tissue of mice with hypoxia-induced PAH, and its pharmacological inhibition by C75 ameliorated right ventricle cardiac function as revealed by echocardiographic analysis. Based on transmission electron microscopy and Seahorse assays, the mitochondrial function of mice with hypoxia was abnormal but was partially reversed after C75 injection. In vitro studies also showed an increase in the expression of FAS in hypoxia-induced human pulmonary artery smooth muscle cells (HPASMCs), which could be attenuated by FAS shRNA as well as C75 treatment. Meanwhile, C75 treatment reversed hypoxia-induced oxidative stress and activated PI3K/AKT signaling. shRNA-mediated inhibition of FAS reduced its expression and oxidative stress levels and improved mitochondrial respiratory capacity and ATP levels of hypoxia-induced HPASMCs. CONCLUSIONS: Inhibition of FAS plays a crucial role in shielding mice from hypoxia-induced PAH, which was partially achieved through the activation of PI3K/AKT signaling, indicating that the inhibition of FAS may provide a potential future direction for reversing PAH in humans.