1.Lysosomes as Regulators of Cancer Stemness and Drug Resistance
Fa-Xiao ZHOU ; Di-Ping YU ; Si-Qi TAN ; Hong-Yu DUAN ; Xiao-Ming WU
Progress in Biochemistry and Biophysics 2026;53(4):951-967
Cancer stem cells (CSCs) represent a distinct subpopulation of cells characterized by self-renewal capacity, differentiation potential, and critical roles in driving tumor progression, therapeutic resistance, recurrence, and maintenance of the tumor microenvironment. Targeting CSCs has emerged as a pivotal direction in cancer research, offering novel strategies to overcome drug resistance and prevent metastasis and relapse. Lysosomes, traditionally recognized as central organelles for intracellular degradation and recycling, are indispensable for cellular homeostasis. Dysregulation of lysosomal function is intimately linked to various diseases, including cancer. In tumors, aberrant lysosomal activity can promote malignant progression through mechanisms such as altering metabolic pathways, enhancing lysosomal exocytosis, modulating drug resistance, and interfering with autophagy-lysosomal pathways. Recent studies have underscored the involvement of lysosomes in regulating CSC properties. This review synthesizes findings on lysosomal regulation of CSCs through the following aspects. (1) Lysosomes exert complex and critical bidirectional control over CSC stemness maintenance through three degradation pathways that are dependent on their degradative function. (i) The lysophagy pathway. This pathway exhibits dual roles. Activation can sustain CSC functions; for instance, in glioblastoma, hypoxia upregulates Gal-8 via the STAT3/HIF1α signaling axis to induce autophagy, supporting stem cell survival. In head and neck squamous cell carcinoma, degradation of GSK3β activates the Wnt pathway, enhancing stemness. Conversely, this pathway can suppress stemness by degrading stemness-related proteins such as BMI-1 and OCT4A, thereby impairing CSC self-renewal capacity. (ii) Mitophagy pathway. In non-small cell lung cancer stem cells, mitophagy-related mechanisms, such as the accumulation of mitochondrial DNA (mtDNA) activating the TLR9-Notch1-AMPK signaling axis, have been shown to promote CSC proliferation. (iii) Autophagosome-dependent lysosomal degradation pathway. This pathway directly regulates stemness-related proteins in a bidirectional manner. Enhanced degradative function can promote CSC properties, exemplified by the degradation of NUMB to activate Notch signaling. Conversely, attenuated degradative function can also enhance stemness by stabilizing oncoproteins (e.g., protecting Frizzled-1 from degradation to sustain Wnt signaling) or preventing the degradation of tumor suppressors (e.g., inhibiting Notch degradation). (2) Constituent proteins of lysosomes, including membrane proteins and luminal acid hydrolases, participate in regulating CSC stemness. Regarding membrane proteins, LAMP2A facilitates chaperone-mediated autophagy to maintain stemness in glioblastoma and ovarian cancer. V-ATPase, by maintaining an acidic luminal environment, promotes proliferation and drug resistance in glioma stem cells. Among hydrolases, cathepsins B and L are highly expressed in pancreatic and ovarian cancers and correlate with poor prognosis. Furthermore, targeting lysosomes to induce lysosomal membrane permeabilization (LMP) triggers lysosome-mediated cell death, presenting a potential therapeutic strategy for eradicating CSCs.(3) The acidic luminal environment, single-membrane structure, and the presence of transmembrane transporters (e.g., ABCA3) enable lysosomes to passively trap or actively uptake and sequester chemotherapeutic drugs. Subsequent drug extrusion via exocytosis confers drug resistance. In CSCs, this lysosome-mediated drug sequestration, often cooperating with autophagy, establishes multimodal drug resistance. Therefore, targeting lysosomal function represents a potential strategy to overcome therapy resistance. The central role of lysosomes in regulating CSC stemness and resistance positions them as highly promising therapeutic targets. Strategies aimed at disrupting lysosomal function to selectively eliminate CSCs include: inhibiting the lysosome-autophagy system using agents like IITZ or lovastatin; inducing lysosomal membrane permeabilization (LMP) with compounds such as hexamethylene amiloride to compromise membrane stability; and disrupting the acidic luminal environment using drugs like siramesine or the K/H transport compound 2. In conclusion, lysosomes critically regulate CSC stemness maintenance and drug resistance through degradative pathways, membrane protein functions, luminal hydrolase activities, and drug sequestration mechanisms. This redefines the lysosome from a traditional “waste disposal unit” to a “signal integration center” in CSCs. The duality and context-dependency of lysosomal function in CSCs offer novel insights into the heterogeneity observed across different tumors. Targeting lysosomal vulnerabilities—such as inducing LMP, disrupting acidity, or blocking autophagic flux—provides a strategy to bypass canonical CSC resistance mechanisms and directly trigger cell death. This establishes the lysosome as a key target to overcome CSC-mediated therapy resistance, paving the way for developing diverse candidate drugs and innovative combination therapies in oncology.
2.From blood transfusion to blood use
Zonglong LI ; Chen HOU ; Yu SI ; Delong QIN ; Xiaoliang ZHOU ; Zhaohui TANG
Chinese Journal of Blood Transfusion 2026;39(1):8-15
The promulgation of the Technical Specifications for Clinical Use of Blood (2025 Edition) signifies that China's clinical blood transfusion management has transitioned from mere technical operations to a new stage centered on patient blood management (PBM). Through an in-depth comparison of the new and old specifications, this paper analyzes the core transformations regarding conceptual reconstruction, legal alignment, technological upgrades, and closed-loop management. The new specifications establish PBM principles, reinforce legal safeguards for informed consent and emergency treatment, and construct a comprehensive, refined quality control system by specifying compatibility testing standards and introducing a post-transfusion evaluation system. Medical institutions should seize this opportunity to update management protocols and information systems, deepen multidisciplinary collaboration, and drive the profound transformation of clinical blood use from focusing solely on safety assurance to placing equal emphasis on science and value.
3.Correlation Analysis of Huanglian Jiedu Wan on Syndrome Improvement and Clinical Biomarkers of "Excess Heat-Toxicity" Based on Machine Learning Model
Qi LI ; Keke LUO ; Baolin BIAN ; Hongyu YU ; Mengxiao WANG ; Mengyao TIAN ; Wen XIA ; Yuan MA ; Xinfang ZHANG ; Pengyue LI ; Nan SI ; Hongjie WANG ; Yanyan ZHOU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):162-173
ObjectiveThis paper aims to find the identified and validated clinical biomarker data building upon a clinical study of early-phase phase Ⅱ and investigate the correlation analysis of Huanglian Jiedu Wan on syndrome improvement and clinical biomarkers in the treatment of "excess heat-toxicity" based on a machine learning model. Additionally, the effective prediction of clinical biomarker values for the main symptoms of the "excess heat-toxicity" syndrome was assessed. MethodsA total of 229 patients meeting the inclusion criteria for "excess heat-toxicity" syndrome were randomly divided into the Huanglian Jiedu Wan group and the placebo group. Syndrome score transition matrices were constructed for the Huanglian Jiedu Wan group and the placebo group based on three main symptoms of "excess heat-toxicity" syndrome, such as oral ulcers, sore throat, and gum swelling and pain. Data from the patients with these three syndromes were also integrated for an overall analysis. The corresponding syndrome score transition matrices were further constructed to visualize symptom change trends of the patients in the two groups via heatmaps. Based on the identified and validated clinical biomarkers related to inflammation, oxidative stress, and energy metabolism in the early phase, Spearman correlation analysis was employed to analyze and evaluate the associations between clinical biomarkers and syndrome improvement. Key clinical biomarkers reflecting the effect of Huanglian Jiedu Wan were screened through the comparison of differences between groups. An extreme gradient boosting (XGBoost) algorithm was used to develop a prediction model for main symptom classification, with classification performance evaluated through 10-fold cross-validation. Feature importance analysis was applied to identify variables with the greatest contribution to the prediction result. ResultsThe syndrome transition matrix results indicated that the Huanglian Jiedu Wan group showed a superior effect to the placebo group in improving oral ulcers, sore throat, and overall symptoms, with significant effects observed especially in sore throat and overall symptom analyses (P<0.01). Spearman correlation analysis revealed that several clinical biomarkers positively correlated with "excess heat-toxicity" syndrome and its main symptom improvement, were also called "heat-related biomarkers", including succinic acid, α-ketoglutaric acid, glycine, lactic acid, adenosine monophosphate (AMP), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), and so on. Conversely, clinical biomarkers negatively correlated with symptom severity, were also called "heat-clearing related biomarkers" after administration of Huanglian Jiedu Wan, including malic acid, fumaric acid, cis-aconitic acid, adrenocorticotropic hormone (ACTH), IL-1β, IL-4, IL-8, succinic acid, and citric acid. The XGBoost classification model using all 52 biomarkers as variables achieved an average test accuracy of 0.754 and an average F1 score of 0.777. Feature importance analysis identified the scores of glutamic acid in saliva and IL-6 were the highest in all the variables, with importance scores of 0.081 and 0.080, respectively. After screening out 14 key variables and optimizing the parameters, model performance improved to an average accuracy of 0.758 and an F1 score of 0.798. Feature importance analysis further determined that the glutamic acid in saliva and IL-6 showed obvious changes after screening the variables, confirming the good syndrome prediction ability of the model constructed by these key clinical biomarkers. ConclusionThis study systematically elucidates the correlation between syndrome improvement and clinical biomarkers of Huanglian Jiedu Wan in the treatment of "excess heat-toxicity" syndrome. An XGBoost classification model based on key clinical biomarkers is successfully established, achieving effective prediction of the symptoms related to the "excess heat-toxicity" syndrome such as oral ulcers and sore throat and providing a new insight for objective identification of traditional Chinese medicine syndromes.
4.Correlation Analysis of Huanglian Jiedu Wan on Syndrome Improvement and Clinical Biomarkers of "Excess Heat-Toxicity" Based on Machine Learning Model
Qi LI ; Keke LUO ; Baolin BIAN ; Hongyu YU ; Mengxiao WANG ; Mengyao TIAN ; Wen XIA ; Yuan MA ; Xinfang ZHANG ; Pengyue LI ; Nan SI ; Hongjie WANG ; Yanyan ZHOU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):162-173
ObjectiveThis paper aims to find the identified and validated clinical biomarker data building upon a clinical study of early-phase phase Ⅱ and investigate the correlation analysis of Huanglian Jiedu Wan on syndrome improvement and clinical biomarkers in the treatment of "excess heat-toxicity" based on a machine learning model. Additionally, the effective prediction of clinical biomarker values for the main symptoms of the "excess heat-toxicity" syndrome was assessed. MethodsA total of 229 patients meeting the inclusion criteria for "excess heat-toxicity" syndrome were randomly divided into the Huanglian Jiedu Wan group and the placebo group. Syndrome score transition matrices were constructed for the Huanglian Jiedu Wan group and the placebo group based on three main symptoms of "excess heat-toxicity" syndrome, such as oral ulcers, sore throat, and gum swelling and pain. Data from the patients with these three syndromes were also integrated for an overall analysis. The corresponding syndrome score transition matrices were further constructed to visualize symptom change trends of the patients in the two groups via heatmaps. Based on the identified and validated clinical biomarkers related to inflammation, oxidative stress, and energy metabolism in the early phase, Spearman correlation analysis was employed to analyze and evaluate the associations between clinical biomarkers and syndrome improvement. Key clinical biomarkers reflecting the effect of Huanglian Jiedu Wan were screened through the comparison of differences between groups. An extreme gradient boosting (XGBoost) algorithm was used to develop a prediction model for main symptom classification, with classification performance evaluated through 10-fold cross-validation. Feature importance analysis was applied to identify variables with the greatest contribution to the prediction result. ResultsThe syndrome transition matrix results indicated that the Huanglian Jiedu Wan group showed a superior effect to the placebo group in improving oral ulcers, sore throat, and overall symptoms, with significant effects observed especially in sore throat and overall symptom analyses (P<0.01). Spearman correlation analysis revealed that several clinical biomarkers positively correlated with "excess heat-toxicity" syndrome and its main symptom improvement, were also called "heat-related biomarkers", including succinic acid, α-ketoglutaric acid, glycine, lactic acid, adenosine monophosphate (AMP), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), and so on. Conversely, clinical biomarkers negatively correlated with symptom severity, were also called "heat-clearing related biomarkers" after administration of Huanglian Jiedu Wan, including malic acid, fumaric acid, cis-aconitic acid, adrenocorticotropic hormone (ACTH), IL-1β, IL-4, IL-8, succinic acid, and citric acid. The XGBoost classification model using all 52 biomarkers as variables achieved an average test accuracy of 0.754 and an average F1 score of 0.777. Feature importance analysis identified the scores of glutamic acid in saliva and IL-6 were the highest in all the variables, with importance scores of 0.081 and 0.080, respectively. After screening out 14 key variables and optimizing the parameters, model performance improved to an average accuracy of 0.758 and an F1 score of 0.798. Feature importance analysis further determined that the glutamic acid in saliva and IL-6 showed obvious changes after screening the variables, confirming the good syndrome prediction ability of the model constructed by these key clinical biomarkers. ConclusionThis study systematically elucidates the correlation between syndrome improvement and clinical biomarkers of Huanglian Jiedu Wan in the treatment of "excess heat-toxicity" syndrome. An XGBoost classification model based on key clinical biomarkers is successfully established, achieving effective prediction of the symptoms related to the "excess heat-toxicity" syndrome such as oral ulcers and sore throat and providing a new insight for objective identification of traditional Chinese medicine syndromes.
5.Inhibitory Effect of Solute Carrier Family 7 Member 5 Inhibitor JPH203 on Renal Fibrosis Induced by Unilateral Ureteral Obstruction in Mice
Changwan CUI ; Yiping LU ; Miao YU ; Shuang WANG ; Si WU ; Zhengrong SUN
Laboratory Animal and Comparative Medicine 2026;46(2):205-211
ObjectiveTo investigate the effect of solute carrier family 7 member 5 (SLC7A5) inhibitor JPH203 on renal fibrosis induced by unilateral ureteral obstruction in mice. MethodsSixteen SPF male C57BL/6 mice were randomly divided into the control group and the experimental group, with 8 mice in each group. The mouse model of renal fibrosis was established by unilateral ureteral obstruction. From the third day after surgery, the mice in the control group were intraperitoneally injected with phosphate-buffered saline (PBS) for 11 consecutive days, and the injection dose was 200 μL/d. Mice in the experimental group received intraperitoneal injection of JPH203 (50 mg/kg) every day for 11 days. On day 14, the mice were euthanized, then the kidney tissues were obtained. Hematoxylin and eosin (HE) staining was used to assess renal tissue damage, Masson staining was used to evaluate collagen fiber deposition in the extracellular matrix, and immunohistochemistry was used to detect the levels of fibroblast activation markers α-smooth muscle actin (α-SMA) and collagen type Ⅰ (COL-Ⅰ) in kidney tissues. Western blotting was further performed to measure the expression levels of SLC7A5 and transforming growth factor-β1 (TGF-β1), as well as the phosphorylation levels of mammalian target of rapamycin complex 1 (mTORC1) signaling pathway-related molecules. Real-time quantitative PCR was used to verify changes in the mRNA levels of SLC7A5, α-SMA, and COL-Ⅰ in kidney tissues. ResultsCompared with the control group, the experimental group showed reduced destruction of renal tissue structure and a significantly lower pathological injury score (P<0.05). Additionally, collagen deposition in the extracellular matrix was decreased, and the percentage of collagen fiber area was significantly reduced (P<0.001) in the experimental group. The levels of fibroblast activation markers α-SMA and COL-Ⅰ were significantly lower in the experimental group (both P<0.001). The expression levels of SLC7A5 and TGF-β1 were also significantly decreased (P<0.001), and the phosphorylation levels of mTORC1 signaling pathway-related proteins 4E-BP1 and mTORC1 were significantly reduced (P<0.001). Real-time quantitative PCR confirmed that the mRNA levels of SLC7A5, α- SMA, and COL-Ⅰ in kidney tissues were significantly lower in the experimental group (P<0.001). ConclusionJPH203 may inhibit the progression of renal fibrosis in mice by suppressing SLC7A5 expression, regulating the mTORC1 signaling pathway, and altering fibroblast activation status.
6.Network Pharmacology and Experimental Verification Unraveled The Mechanism of Pachymic Acid in The Treatment of Neuroblastoma
Hang LIU ; Yu-Xin ZHU ; Si-Lin GUO ; Xin-Yun PAN ; Yuan-Jie XIE ; Si-Cong LIAO ; Xin-Wen DAI ; Ping SHEN ; Yu-Bo XIAO
Progress in Biochemistry and Biophysics 2025;52(9):2376-2392
ObjectiveTraditional Chinese medicine (TCM) constitutes a valuable cultural heritage and an important source of antitumor compounds. Poria (Poria cocos (Schw.) Wolf), the dried sclerotium of a polyporaceae fungus, was first documented in Shennong’s Classic of Materia Medica and has been used therapeutically and dietarily in China for millennia. Traditionally recognized for its diuretic, spleen-tonifying, and sedative properties, modern pharmacological studies confirm that Poria exhibits antioxidant, anti-inflammatory, antibacterial, and antitumor activities. Pachymic acid (PA; a triterpenoid with the chemical structure 3β-acetyloxy-16α-hydroxy-lanosta-8,24(31)-dien-21-oic acid), isolated from Poria, is a principal bioactive constituent. Emerging evidence indicates PA exerts antitumor effects through multiple mechanisms, though these remain incompletely characterized. Neuroblastoma (NB), a highly malignant pediatric extracranial solid tumor accounting for 15% of childhood cancer deaths, urgently requires safer therapeutics due to the limitations of current treatments. Although PA shows multi-mechanistic antitumor potential, its efficacy against NB remains uncharacterized. This study systematically investigated the potential molecular targets and mechanisms underlying the anti-NB effects of PA by integrating network pharmacology-based target prediction with experimental validation of multi-target interactions through molecular docking, dynamic simulations, and in vitro assays, aimed to establish a novel perspective on PA’s antitumor activity and explore its potential clinical implications for NB treatment by integrating computational predictions with biological assays. MethodsThis study employed network pharmacology to identify potential targets of PA in NB, followed by validation using molecular docking, molecular dynamics (MD) simulations, MM/PBSA free energy analysis, RT-qPCR and Western blot experiments. Network pharmacology analysis included target screening via TCMSP, GeneCards, DisGeNET, SwissTargetPrediction, SuperPred, and PharmMapper. Subsequently, potential targets were predicted by intersecting the results from these databases via Venn analysis. Following target prediction, topological analysis was performed to identify key targets using Cytoscape software. Molecular docking was conducted using AutoDock Vina, with the binding pocket defined based on crystal structures. MD simulations were performed for 100 ns using GROMACS, and RMSD, RMSF, SASA, and hydrogen bonding dynamics were analyzed. MM/PBSA calculations were carried out to estimate the binding free energy of each protein-ligand complex. In vitro validation included RT-qPCR and Western blot, with GAPDH used as an internal control. ResultsThe CCK-8 assay demonstrated a concentration-dependent inhibitory effect of PA on NB cell viability. GO analysis suggested that the anti-NB activity of PA might involve cellular response to chemical stress, vesicle lumen, and protein tyrosine kinase activity. KEGG pathway enrichment analysis suggested that the anti-NB activity of PA might involve the PI3K/AKT, MAPK, and Ras signaling pathways. Molecular docking and MD simulations revealed stable binding interactions between PA and the core target proteins AKT1, EGFR, SRC, and HSP90AA1. RT-qPCR and Western blot analyses further confirmed that PA treatment significantly decreased the mRNA and protein expression of AKT1, EGFR, and SRC while increasing the HSP90AA1 mRNA and protein levels. ConclusionIt was suggested that PA may exert its anti-NB effects by inhibiting AKT1, EGFR, and SRC expression, potentially modulating the PI3K/AKT signaling pathway. These findings provide crucial evidence supporting PA’s development as a therapeutic candidate for NB.
7.Adiposity, circulating metabolic markers, and risk of cardiometabolic multimorbidity.
Si CHENG ; Zhiqing ZENG ; Jun LV ; Canqing YU ; Dianjianyi SUN ; Pei PEI ; Ling YANG ; Yiping CHEN ; Huaidong DU ; Li GAO ; Xiaoming YANG ; Daniel AVERY ; Junshi CHEN ; Zhengming CHEN ; Liming LI ; Yuanjie PANG
Chinese Medical Journal 2025;138(8):991-993
8.Identification of novel pathogenic variants in genes related to pancreatic β cell function: A multi-center study in Chinese with young-onset diabetes.
Fan YU ; Yinfang TU ; Yanfang ZHANG ; Tianwei GU ; Haoyong YU ; Xiangyu MENG ; Si CHEN ; Fengjing LIU ; Ke HUANG ; Tianhao BA ; Siqian GONG ; Danfeng PENG ; Dandan YAN ; Xiangnan FANG ; Tongyu WANG ; Yang HUA ; Xianghui CHEN ; Hongli CHEN ; Jie XU ; Rong ZHANG ; Linong JI ; Yan BI ; Xueyao HAN ; Hong ZHANG ; Cheng HU
Chinese Medical Journal 2025;138(9):1129-1131
9.SMUG1 promoted the progression of pancreatic cancer via AKT signaling pathway through binding with FOXQ1.
Zijian WU ; Wei WANG ; Jie HUA ; Jingyao ZHANG ; Jiang LIU ; Si SHI ; Bo ZHANG ; Xiaohui WANG ; Xianjun YU ; Jin XU
Chinese Medical Journal 2025;138(20):2640-2656
BACKGROUND:
Pancreatic cancer is a lethal malignancy prone to gemcitabine resistance. The single-strand selective monofunctional uracil DNA glycosylase (SMUG1), which is responsible for initiating base excision repair, has been reported to predict the outcomes of different cancer types. However, the function of SMUG1 in pancreatic cancer is still unclear.
METHODS:
Gene and protein expression of SMUG1 as well as survival outcomes were assessed by bioinformatic analysis and verified in a cohort from Fudan University Shanghai Cancer Center. Subsequently, the effect of SMUG1 on proliferation, cell cycle, and migration abilities of SMUG1 cells were detected in vitro . DNA damage repair, apoptosis, and gemcitabine resistance were also tested. RNA sequencing was performed to determine the differentially expressed genes and signaling pathways, followed by quantitative real-time polymerase chain reaction and Western blotting verification. The cancer-promoting effect of forkhead box Q1 (FOXQ1) and SMUG1 on the ubiquitylation of myelocytomatosis oncogene (c-Myc) was also evaluated. Finally, a xenograft model was established to verify the results.
RESULTS:
SMUG1 was highly expressed in pancreatic tumor tissues and cells, which also predicted a poor prognosis. Downregulation of SMUG1 inhibited the proliferation, G1 to S transition, migration, and DNA damage repair ability against gemcitabine in pancreatic cancer cells. SMUG1 exerted its function by binding with FOXQ1 to activate the Protein Kinase B (AKT)/p21 and p27 pathway. Moreover, SMUG1 also stabilized the c-Myc protein via AKT signaling in pancreatic cancer cells.
CONCLUSIONS
SMUG1 promotes proliferation, migration, gemcitabine resistance, and c-Myc protein stability in pancreatic cancer via protein kinase B signaling through binding with FOXQ1. Furthermore, SMUG1 may be a new potential prognostic and gemcitabine resistance predictor in pancreatic ductal adenocarcinoma.
Humans
;
Pancreatic Neoplasms/pathology*
;
Forkhead Transcription Factors/genetics*
;
Signal Transduction/genetics*
;
Animals
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Cell Line, Tumor
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Cell Proliferation/physiology*
;
Mice
;
Uracil-DNA Glycosidase/genetics*
;
Female
;
Male
;
Gemcitabine
;
Mice, Nude
;
Apoptosis/physiology*
;
Deoxycytidine/analogs & derivatives*
;
Cell Movement/genetics*
10.The regulation and mechanism of apolipoprotein A5 on myocardial lipid deposition.
Xiao-Jie YANG ; Jiang LI ; Jing-Yuan CHEN ; Teng-Teng ZHU ; Yu-Si CHEN ; Hai-Hua QIU ; Wen-Jie CHEN ; Xiao-Qin LUO ; Jun LUO
Acta Physiologica Sinica 2025;77(1):35-46
The current study aimed to clarify the roles of apolipoprotein A5 (ApoA5) and milk fat globule-epidermal growth factor 8 (Mfge8) in regulating myocardial lipid deposition and the regulatory relationship between them. The serum levels of ApoA5 and Mfge8 in obese and healthy people were compared, and the obesity mouse model induced by the high-fat diet (HFD) was established. In addition, primary cardiomyocytes were purified and identified from the hearts of suckling mice. The 0.8 mmol/L sodium palmitate treatment was used to establish the lipid deposition cardiomyocyte model in vitro. ApoA5-overexpressing adenovirus was used to observe its effects on cardiac function and lipids. The expressions of the fatty acid uptake-related molecules and Mfge8 on transcription or translation levels were detected. Co-immunoprecipitation was used to verify the interaction between ApoA5 and Mfge8 proteins. Immunofluorescence was used to observe the co-localization of Mfge8 protein with ApoA5 or lysosome-associated membrane protein 2 (LAMP2). Recombinant rMfge8 was added to cardiomyocytes to investigate the regulatory mechanism of ApoA5 on Mfge8. The results showed that participants in the simple obesity group had a significant decrease in serum ApoA5 levels (P < 0.05) and a significant increase in Mfge8 levels (P < 0.05) in comparison with the healthy control group. The adenovirus treatment successfully overexpressed ApoA5 in HFD-fed obese mice and palmitic acid-induced lipid deposition cardiomyocytes, respectively. ApoA5 reduced the weight of HFD-fed obese mice (P < 0.05), shortened left ventricular isovolumic relaxation time (IVRT), increased left ventricular ejection fraction (LVEF), and significantly reduced plasma levels of triglycerides (TG) and cholesterol (CHOL) (P < 0.05). In myocardial tissue and cardiomyocytes, the overexpression of ApoA5 significantly reduced the deposition of TG (P < 0.05), transcription of fatty acid translocase (FAT/CD36) (P < 0.05), fatty acid-binding protein (FABP) (P < 0.05), and fatty acid transport protein (FATP) (P < 0.05), and protein expression of Mfge8 (P < 0.05), while the transcription levels of Mfge8 were not significantly altered (P > 0.05). In vitro, the Mfge8 protein was captured using ApoA5 as bait protein, indicating a direct interaction between them. Overexpression of ApoA5 led to an increase in co-localization of Mfge8 with ApoA5 or LAMP2 in cardiomyocytes under lipid deposition status. On this basis, exogenous added recombinant rMfge8 counteracted the improvement of lipid deposition in cardiomyocytes by ApoA5. The above results indicate that the overexpression of ApoA5 can reduce fatty acid uptake in myocardial cells under lipid deposition status by regulating the content and cellular localization of Mfge8 protein, thereby significantly reducing myocardial lipid deposition and improving cardiac diastolic and systolic function.
Animals
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Humans
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Mice
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Myocytes, Cardiac/metabolism*
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Obesity/physiopathology*
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Male
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Apolipoprotein A-V/blood*
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Lipid Metabolism/physiology*
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Milk Proteins/blood*
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Myocardium/metabolism*
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Diet, High-Fat
;
Antigens, Surface/physiology*
;
Mice, Inbred C57BL
;
Cells, Cultured
;
Female

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