Objective:X-linked non-syndromic hearing loss is an extremely rare type of hearing impairment. This study conducted a phenotypic and genetic analysis of a family with X-linked dominant inheritance to explore the causes of hearing loss. Methods:Clinical data were collected from a patient with non-syndromic hearing loss who visited the Otorhinolaryngology Department of the First Affiliated Hospital of Zhengzhou University in June 2023. Phenotypic and genetic analyses were performed on family members, including audiometric tests, whole-exome sequencing, and PCR-Sanger sequencing verification. Audiological assessments comprised pure-tone audiometry, impedance audiometry, auditory brainstem response, and otoacoustic emission tests. Results:The affected individuals in this pedigree have X-linked dominant non-syndromic deafness caused by mutations in the SMPX gene. The proband, along with their mother and maternal grandmother, exhibit varying degrees of sensorineural hearing loss. Whole-exome sequencing revealed a novel pathogenic variant, NM_014332.3: c. 133-2A>C, in the SMPX gene in the proband. Sanger sequencing confirmed that the proband, proband's mother, and grandmother all carried this pathogenic variant. Conclusion:This study reports a novel pathogenic variant in the SMPX gene, providing additional medical evidence for the diagnosis and treatment of X-linked dominant inherited non-syndromic hearing loss. It enriches the mutation spectrum of the SMPX gene.
Humans ; Pedigree ; Mutation ; Phenotype ; Male ; Hearing Loss, Sensorineural/genetics* ; Exome Sequencing ; Female ; Adult ; Hearing Loss/genetics* ; Evoked Potentials, Auditory, Brain Stem ; Muscle Proteins

Objective:To investigate the molecular characteristics and clinical heterogeneity of Usher syndrome（USH） -related gene variants in patients with hereditary hearing loss in southwest China, providing a basis for early diagnosis and clinical management. Methods:Thirteen patients from twelve families with hearing loss who attended the Affiliated Children's Hospital of Kunming Medical University between January 2017 and March 2021 were enrolled. All patients were identified as carrying USH-related gene variants through next-generation sequencing. Sanger sequencing was performed for all patients and their parents to validate the pathogenic variants. Comprehensive clinical evaluations, including medical history collection, otologic and ophthalmologic examinations, and vestibular function assessments, were conducted. Results:Among the 13 patients, 4 were diagnosed with USH type 1 and 2 with USH type 2. A total of 19 pathogenic or likely pathogenic variants were detected in USH-related genes, including MYO7A,CDH23,USH1C, and USH2A. The causative gene was MYO7A in 3 probands, CDH23 in 5, USH1C in 3, and USH2Ain 2. All patients exhibited an autosomal recessive inheritance pattern. Vestibular dysfunction was observed in 4 patients, and retinitis pigmentosa（RP） in 3 patients. Based on the genotype-phenotype correlation, 6 patients were initially diagnosed with USH, while 7 were classified as having non-syndromic hearing loss（NSHL）. Conclusion:This study revealed the clinical heterogeneity of USH-related gene variants in patients with hereditary deafness in southwest China. Although the clinical manifestations of USH are complex and there are overlapping characteristics between different subtypes, genetic testing provides an important basis for early diagnosis and precise clinical management. Especially for those with typical hearing loss, early genetic diagnosis can provide a window of time for early detection and intervention of retinitis pigmentosa.
Humans ; Usher Syndromes/genetics* ; Myosin VIIa ; Phenotype ; Male ; Female ; Myosins/genetics* ; Mutation ; Cadherins/genetics* ; Child ; Extracellular Matrix Proteins/genetics* ; Adolescent ; Pedigree ; High-Throughput Nucleotide Sequencing ; Cadherin Related Proteins ; Cytoskeletal Proteins ; Cell Cycle Proteins

OBJECTIVES: To investigate the synergistic mechanism of the traditional Chinese medicine Rosa laevigata Michx. (RLM) for treatment of pulmonary arterial hypertension (PAH). METHODS: Network pharmacological analysis was carried out to screen the active ingredients of RLM and PAH disease targets and construct the "component-target-disease" interaction network, followed by gene enrichment analysis and molecular docking studies. In the cell experiments, primary cultures of rat pulmonary arterial smooth muscle cells were exposed to hypoxia for 24 h and treated with solvent or 100, 200 and 300 mg/mL RLM, and the changes in cell proliferation were detected using Western blotting for PCNA and immunofluorescence staining. In the animal experiment, male SD rats were randomized into 5 control group, monocrotaline (MCT) solvent group, and MCT with RLM (100, 200 and 300 mg/mL) treatment groups. HE staining and immunofluorescence staining were used to observe histopathological changes in the pulmonary blood vessels of the rats. RESULTS: Seven core active ingredients (including β-sitosterol and kaempferol) in RLM and 39 key disease targets were identified, and molecular docking showed that SRC was a high-affinity target. KEGG enrichment analysis showed that the differential genes were significantly enriched in calcium signaling and PI3K-AKT pathways. In rat pulmonary arterial smooth muscle cells, hypoxic exposure significantly up-regulated cellular expression of PCNA and phosphorylation levels of Src and AKT1, which were obviously lowered by RLM treatment. In RLM-treated rat models, the mean pulmonary artery pressure and right ventricular hypertrophy index (Fulton index) were significantly reduced, the tricuspid annular plane systolic excursion (TAPSE) was improved, and pulmonary vascular wall thickening and fibrosis were obviously ameliorated. CONCLUSIONS RLM inhibits pulmonary arterial smooth muscle cell proliferation in rat models of hypertension possibly by regulating the Src-AKT1 axis, suggesting the potential of RLM as a new natural drug for treatment of pulmonary hypertension.
Animals ; Cell Proliferation/drug effects* ; Proto-Oncogene Proteins c-akt/metabolism* ; Rats, Sprague-Dawley ; Pulmonary Artery/cytology* ; Male ; Rats ; Myocytes, Smooth Muscle/cytology* ; Hypertension, Pulmonary/pathology* ; Drugs, Chinese Herbal/pharmacology* ; Signal Transduction/drug effects* ; Muscle, Smooth, Vascular/cytology* ; src-Family Kinases/metabolism* ; Cells, Cultured

Microglial functions are linked to Ca²⁺ signaling, with endoplasmic reticulum (ER) calcium stores playing a crucial role. Microglial abnormality is a hallmark of Alzheimer's disease (AD), but how ER Ca²⁺ receptors regulate microglial functions under physiological and AD conditions remains unclear. We found reduced ryanodine receptor 2 (Ryr2) expression in microglia from an AD mouse model. Modulation of RyR2 using S107, a RyR-Calstabin stabilizer, blunted spontaneous Ca²⁺ transients in controls and normalized Ca²⁺ transients in AD mice. S107 enhanced ATP-induced migration and phagocytosis while reducing ramification in control microglia; however, these effects were absent in AD microglia. Our findings indicate that RyR2 stabilization promotes an activation state shift in control microglia, a mechanism impaired in AD. These results highlight the role of ER Ca²⁺ receptors in both homeostatic and AD microglia, providing insights into microglial Ca²⁺ malfunctions in AD.
Animals ; Microglia/pathology* ; Alzheimer Disease/pathology* ; Phagocytosis/drug effects* ; Ryanodine Receptor Calcium Release Channel/metabolism* ; Disease Models, Animal ; Mice ; Cell Movement/drug effects* ; Mice, Transgenic ; Calcium Signaling/physiology* ; Calcium/metabolism* ; Mice, Inbred C57BL ; Male ; Endoplasmic Reticulum/metabolism*

Five previously undescribed diterpenoids, named succipenoids D‒H (1‒5), along with four undescribed lignans, named succignans A‒D (6‒9), were isolated from the dichloromethane extract of Chinese medicinal succinum. Compounds 1‒5 were characterized as nor-abietane diterpenoids, while compounds 6‒9 were identified as lignans polymerized from two groups of phenylpropanoid units. The structures of these novel compounds, including their absolute configurations, were determined through spectroscopic and computational methods. Biological assessments of renal fibrosis demonstrated that compounds 6 and 7 effectively reduce the expression of proteins associated with renal fibrosis, including α-smooth muscle actin (α-SMA), collagen I, and fibronectin in transforming growth factor-β1 (TGF-β1) induced normal rat kidney proximal tubular epithelial cells (NRK-52e).
Animals ; Rats ; Lignans/isolation & purification* ; Diterpenes/isolation & purification* ; Fibrosis/drug therapy* ; Drugs, Chinese Herbal/pharmacology* ; Molecular Structure ; Cell Line ; Kidney Diseases/pathology* ; Transforming Growth Factor beta1/genetics* ; Kidney/metabolism* ; Actins/genetics* ; Fibronectins/genetics* ; Collagen Type I/genetics* ; Epithelial Cells/metabolism*

OBJECTIVE: To explore the effect and mechanism of acupuncture at "Weizhong" (BL40) on microcirculation of paravertebral skeletal muscle in rats with chronic blunt injury of lumbar muscle based on the insulin-like growth factor-1 (IGF-1)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway. METHODS: Forty-eight SPF-grade SD rats were randomized into a blank group (8 rats) and a modeling group (40 rats). Chronic blunt injury model was established by weight impact method in the modeling group. Forty rats were successfully modeled, and were randomly divided into a model group, an acupuncture at Weizhong group (Weizhong group), an acupuncture at non-acupoint group (non-acupoint group), an inhibitor group, and an inhibitor+acupuncture at Weizhong group (inhibitor+Weizhong group), 8 rats in each group. In the Weizhong group and the inhibitor+Weizhong group, acupuncture was applied at bilateral "Weizhong" (BL40). In the non-acupoint group, acupuncture was applied at non-acupoints, i.e. points 0.5 cm inward from bilateral "Weizhong" (BL40). The acupuncture intervention was delivered 20 min each time, once a day for continuous 2 weeks. In the inhibitor group and the inhibitor+Weizhong group, intraperitoneal injection of IGF-1 receptor (IGF-1R) inhibitor was given once a day, at a dosage of 2 mg/100 g, for continuous 2 weeks. Before modeling and on the 1st, 7th and 14th days of intervention, the body mass was measured. Before and after modeling, and after intervention, the limb grip strength and paw withdrawal threshold (PWT) were measured. After intervention, the morphology of psoas muscle was observed by HE staining; the ultrastructure of psoas muscle capillaries was observed by electron microscopy; the levels of serum vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) were detected by ELISA; and the protein and mRNA expression of IGF-1, IGF-1R, PI3K, AKT of psoas muscle was detected by Western blot and real-time PCR. RESULTS: Compared with the blank group, in the model group, the body mass on the 7th and 14th days of intervention, the limb grip strength, and the PWT of left and right hind feet were decreased (P<0.001, P<0.01); the skeletal muscle cells showed enlarged intercellular space, loosely arranged and irregularly shaped, the capillaries in the psoas muscle tissues were edematous, and the lumen of the blood vessels was obviously atrophied; the levels of serum VEGF and eNOS were decreased (P<0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K, p-AKT/AKT values were decreased (P<0.001), the mRNA expression of IGF-1, IGF-1R, PI3K and AKT was decreased (P<0.001, P<0.05). Compared with the model group, in the Weizhong group, the body weight was increased on the 7th and 14th days of intervention (P<0.001), the limb grip strength and the PWT of the left and right hind feet were increased (P<0.001, P<0.01); the arrangement of the skeletal muscle cells was relatively tight and the intercellular space was reduced, the blood vessels tended to be regular and the structure of the basement membrane was continuous, while the lumens of blood vessels were collapsed locally; the levels of serum VEGF and eNOS were increased (P<0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K, p-AKT/AKT values were increased (P<0.001), the mRNA expression of IGF-1, IGF-1R, PI3K and AKT was increased (P<0.001, P<0.01). Compared with the model group, in the inhibitor group, the body mass was decreased on the 7th and 14th days of intervention (P<0.05, P<0.01); the limb grip strength and the PWT of the left hind foot were decreased (P<0.01, P<0.001); the intercellular space of skeletal muscle cells was larger, the nuclei of the cells and erythrocytes were scattered in the intercellular space, the damage of the capillaries in the muscular tissues was serious, the collagen fibers were sparsely distributed and disorganized; the levels of serum VEGF and eNOS were decreased (P<0.001, P<0.01); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K and p-AKT/AKT values were decreased (P<0.01, P<0.05, P<0.001), the mRNA expression of IGF-1, IGF-1R, PI3K, and AKT was decreased (P<0.01, P<0.001, P<0.05). Compared with the Weizhong group, in the non-acupoint group and the inhibitor+Weizhong group, the body mass was decreased on the 7th and 14th days of intervention (P<0.001, P<0.01), the limb grip strength was decreased (P<0.001); the morphology of muscle cell was relatively poor, with generally irregular, there was mild collapse and atrophy in the vascular lumen, and mild edema in the endothelial cells; the levels of serum VEGF and eNOS were decreased (P<0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K and p-AKT/AKT values were decreased (P<0.01, P<0.001), the mRNA expression of IGF-1, IGF-1R, PI3K, and AKT was decreased (P<0.001, P<0.01, P<0.05). Compared with the Weizhong group, the PWT of the left hind foot was decreased in the non-acupoint group (P<0.001), and PWT of the left and right hind feet was decreased in the inhibitor+Weizhong group (P<0.001). CONCLUSION Acupuncture at "Weizhong" (BL40) promotes lumbar muscle repair in chronic low back pain, its mechanism may be related to the activation of the IGF-1/PI3K/AKT pathway, thereby improving the microcirculation.
Animals ; Insulin-Like Growth Factor I/genetics* ; Acupuncture Therapy ; Rats, Sprague-Dawley ; Rats ; Proto-Oncogene Proteins c-akt/genetics* ; Male ; Humans ; Muscle, Skeletal/metabolism* ; Signal Transduction ; Phosphatidylinositol 3-Kinases/genetics* ; Wounds, Nonpenetrating/metabolism* ; Acupuncture Points

BACKGROUND: The main cause of restenosis after percutaneous transluminal angioplasty (PTA) is the excessive proliferation and migration of vascular smooth muscle cells (VSMCs). Lin28a has been reported to play critical regulatory roles in this process. However, whether CCAAT/enhancer-binding proteins β (C/EBPβ) binds to the Lin28a promoter and drives the progression of restenosis has not been clarified. Therefore, in the present study, we aim to clarify the role of C/EBPβ-Lin28a axis in restenosis. METHODS: Restenosis and atherosclerosis rat models of type 2 diabetes ( n   =  20, for each group) were established by subjecting to PTA. Subsequently, the difference in DNA methylation status and expression of C/EBPβ between the two groups were assessed. EdU, Transwell, and rescue assays were performed to assess the effect of C/EBPβ on the proliferation and migration of VSMCs. DNA methylation status was further assessed using Methyltarget sequencing. The interaction between Lin28a and ten-eleven translocation 1 (TET1) was analysed using co-immunoprecipitation (Co-IP) assay. Student's t -test and one-way analysis of variance were used for statistical analysis. RESULTS: C/EBPβ expression was upregulated and accompanied by hypomethylation of its promoter in restenosis when compared with atherosclerosis. In vitroC/EBPβ overexpression facilitated the proliferation and migration of VSMCs and was associated with increased Lin28a expression. Conversely, C/EBPβ knockdown resulted in the opposite effects. Chromatin immunoprecipitation assays further demonstrated that C/EBPβ could directly bind to Lin28a promoter. Increased C/EBPβ expression and enhanced proliferation and migration of VSMCs were observed after decitabine treatment. Further, mechanical stretch promoted C/EBPβ and Lin28a expression accompanied by C/EBPβ hypomethylation. Additionally, Lin28a overexpression reduced C/EBPβ methylation via recruiting TET1 and enhanced C/EBPβ-mediated proliferation and migration of VSMCs. The opposite was noted in Lin28a knockdown cells. CONCLUSION Our findings suggest that the C/EBPβ-Lin28a axis is a driver of restenosis progression, and presents a promising therapeutic target for restenosis.
Animals ; Cell Proliferation/genetics* ; Cell Movement/genetics* ; Muscle, Smooth, Vascular/metabolism* ; Rats ; DNA Methylation/physiology* ; CCAAT-Enhancer-Binding Protein-beta/genetics* ; Male ; Myocytes, Smooth Muscle/cytology* ; Rats, Sprague-Dawley ; RNA-Binding Proteins/genetics* ; Cells, Cultured ; Coronary Restenosis/metabolism*

The present study aimed to investigate the effects of eccentric treadmill exercise on adaptive hypertrophy of skeletal muscle in rats. Thirty-two 3-month-old Sprague Dawley (SD) rats were selected and randomly assigned to one of the four groups based on their body weights: 2-week quiet control group (2C), 2-week downhill running exercise group (2E), 4-week quiet control group (4C), and 4-week downhill running exercise group (4E). The downhill running protocol for rats in the exercise groups involved slope of -16°, running speed of 16 m/min, training duration of 90 min, and 5 training sessions per week. Twenty-four hours after the final session of training, all the four groups of rats underwent an exhaustion treadmill exercise. After resting for 48 h, all the rats were euthanized and their gastrocnemius muscles were harvested for analysis. HE staining was used to measure the cross-sectional area (CSA) and diameter of muscle fibers. Transmission electron microscope was used to observe the ultrastructural changes in muscle fibers. Purithromycin surface labeling translation method was used to measure protein synthesis rate. Immunofluorescence double labeling was used to detect the colocalization levels of lysosomal-associated membrane protein 2 (Lamp2)-leucyl-tRNA synthetase (LARS) and Lamp2-mammalian target of rapamycin (mTOR). Western blot was used to measure the protein expression levels of myosin heavy chain (MHC) IIb and LARS, as well as the phosphorylation levels of mTOR, p70 ribosomal protein S6 kinase (p70S6K), and eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1). The results showed that, compared with the 2C group rats, the 2E group rats showed significant increases in wet weight of gastrocnemius muscle, wet weight/body weight ratio, running distance, running time, pre- and post-exercise blood lactate levels, myofibrillar protein content, colocalization levels of Lamp2-LARS and Lamp2-mTOR, and LARS protein expression. Besides these above changes, compared with the 4C group, the 4E group further exhibited significantly increased fiber CSA, fiber diameter, protein synthesis rate, and phosphorylation levels of mTOR, p70S6K, and 4E-BP1. Compared with the quiet control groups, the exercise groups exhibited ultrastructural damage of rat gastrocnemius muscle, which was more pronounced in the 4E group. These findings suggest that eccentric treadmill exercise may promote mTOR translocation to lysosomal membrane, activating mTOR signaling via up-regulating LARS expression. This, in turn, increases protein synthesis rate through the mTOR-p70S6K-4E-BP1 signaling pathway, promoting protein deposition and inducing adaptive skeletal muscle hypertrophy. Although the ultrastructural changes of skeletal muscle are more pronounced, the relatively long training cycles during short-term exercise periods have a more significant effect on promoting gastrocnemius muscle protein synthesis and adaptive hypertrophy.
Animals ; Rats, Sprague-Dawley ; Physical Conditioning, Animal/physiology* ; Rats ; Muscle, Skeletal/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; Male ; Hypertrophy ; Adaptation, Physiological/physiology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Ribosomal Protein S6 Kinases, 70-kDa/metabolism* ; Intracellular Signaling Peptides and Proteins

Objective To explore the mechanism by which gentiopicroside (GPS) prevents macrophage-mediated hepatic fibrosis by regulating the macrophage migration inhibitory factor (MIF)-secreted phosphoprotein 1 (SPP1) signaling pathway in hepatic stellate cells. Methods LX-2 cells were divided into control group, transforming growth factor β(TGF-β) group, and TGF-β combined with GPS (25, 50, 100, 150 μmol/mL) groups. Cell proliferation was detected by EDU assay, cell invasion was assessed by Transwell^TM assay, and the protein expressions of α-smooth muscle actin (α-SMA) and type I collagen (COL1A1) were measured by Western blot. M1-type macrophage-conditioned medium (M1-CM) was used to treat LX-2 cells in the TGF-β group and TGF-β combined with GPS group. The concentrations of inducible nitric oxide synthase (iNOS) and arginase 1 (Arg1) in the cell supernatant, as well as cell proliferation, invasion ability, and the expressions of α-SMA and COL1A1 were detected. Bioinformatics analysis was performed to identify the target intersections of GPS, hepatic fibrosis, and macrophage-related genes. Drug affinity responsive target stability (DARTS) experiments and Western blot were used to verify the regulatory effect of GPS on MIF. Furthermore, LX-2 cells were divided into control group, TGF-β group, TGF-β combined with M2-CM group, TGF-β and oe-NC combined with M2-CM group, and TGF-β and oe-MIF combined with M2-CM group to analyze the concentrations of iNOS and Arg1 in the cell supernatant, as well as changes in cell proliferation, invasion, and the expressions of α-SMA and COL1A1. LX-2 cells were also divided into control group, TGF-β group, TGF-β combined with oe-NC group, TGF-β combined with oe-MIF group, and TGF-β and oe-MIF combined with GPS group to determine the protein expressions of MIF and SPP1 by Western blot. A rat model of hepatic fibrosis was constructed to explore the potential therapeutic effects of GPS on hepatic fibrosis in vivo. Results Compared with the control group, the proliferation and invasion abilities of LX-2 cells in the TGF-β group were increased, and the protein expressions of α-SMA and COL1A1 were enhanced. GPS intervention inhibited the proliferation and invasion of LX-2 cells under TGF-β conditions and reduced the expressions of α-SMA and COL1A1. Compared with the control group, the concentration of iNOS in the cell supernatant of the TGF-β group was upregulated, while the concentration of Arg1 was decreased. M1-CM treatment further increased the concentration of iNOS, decreased the concentration of Arg1, and promoted cell proliferation and invasion, as well as upregulated the expressions of α-SMA and COL1A1 on the basis of TGF-β intervention. However, GPS could reverse the effects of M1-CM intervention. Bioinformatics analysis revealed that MIF was one of the target intersections of GPS, hepatic fibrosis, and macrophage-related genes, and GPS could target and inhibit its expression. Compared with the TGF-β group, after M2-CM intervention, the concentration of iNOS in the cell supernatant decreased, the concentration of Arg1 increased, the proliferation and invasion abilities of LX-2 cells were reduced, and the expressions of α-SMA and COL1A1 were weakened. However, overexpression of MIF reversed the effects of M2-CM intervention. Western blot results showed that compared with the control group, the protein expressions of MIF and SPP1 were enhanced in the TGF-β group. Overexpression of MIF further enhanced the expressions of MIF and SPP1, while GPS intervention inhibited the expressions of MIF and SPP1. In the animal experiment, GPS intervention treatment alleviated liver injury in rats with hepatic fibrosis and inhibited the expressions of MIF and SPP1, as well as α-SMA and COL1A1 in liver tissue. Conclusion GPS may prevent macrophage-mediated hepatic fibrosis by inhibiting the MIF-SPP1 signaling pathway in hepatic stellate cells.
Hepatic Stellate Cells/metabolism* ; Signal Transduction/drug effects* ; Macrophage Migration-Inhibitory Factors/genetics* ; Liver Cirrhosis/prevention & control* ; Macrophages/drug effects* ; Iridoid Glucosides/pharmacology* ; Humans ; Cell Proliferation/drug effects* ; Animals ; Cell Line ; Collagen Type I/metabolism* ; Collagen Type I, alpha 1 Chain ; Intramolecular Oxidoreductases/genetics* ; Rats ; Transforming Growth Factor beta/pharmacology* ; Actins/metabolism*

Objective To explore the role and mechanism of mammalian target of rapamycin (mTOR) in oxidized low-density lipoprotein (oxLDL)-induced ferroptosis in vascular smooth muscle cells (VSMCs). Methods A model of oxLDL-induced VSMC ferroptosis was established. VSMCs were co-treated with either the mTOR inhibitor rapamycin or the autophagy inducer carbonyl cyanide m-chlorophenylhydrazone (CCCP), followed by detection of autophagy and ferroptosis-related indexes. Quantitative real-time PCR and Western blot were used respectively to analyze the expression of mTOR, glutathione peroxidase 4 (GPX4), sequestosome 1 (p62), and microtubule-associated protein 1 light chain 3 (LC3). Flow cytometry was employed to assess VSMC death. C11 BODIPY fluorescent staining was used to measure cellular lipid peroxidation levels. Colorimetric assays were performed to determine the contents of malondialdehyde (MDA), ferrous ion (Fe²⁺) and glutathione (GSH). Results oxLDL significantly upregulated mTOR expression in VSMCs, while increasing p62 expression and reducing LC3 expression, thereby suppressing VSMC autophagy. Compared with oxLDL treatment alone, rapamycin co-treatment reversed oxLDL-induced VSMC ferroptosis, as characterized by reduced VSMC death, increased GPX4 expression and GSH contents, along with decreased MDA content, Fe²⁺ content and lipid peroxidation levels. Similarly, CCCP co-treatment activated autophagy characterized by reduced p62 expression and elevated LC3 expression, which subsequently alleviated oxLDL-induced ferroptosis, showing reduced VSMC death, increased GPX4 expressions and GSH contents, and decreased MDA content, Fe²⁺ content and lipid peroxidation levels. Moreover, mTOR inhibition by rapamycin significantly reversed the oxLDL-induced upregulation of p62 and downregulation of LC3. Conclusion mTOR may promote oxLDL-induced VSMC ferroptosis by suppressing autophagy.
Ferroptosis/drug effects* ; Lipoproteins, LDL/metabolism* ; TOR Serine-Threonine Kinases/physiology* ; Autophagy/drug effects* ; Muscle, Smooth, Vascular/metabolism* ; Animals ; Rats ; Myocytes, Smooth Muscle/cytology* ; Cells, Cultured ; Lipid Peroxidation/drug effects* ; Sequestosome-1 Protein/genetics* ; Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism* ; Microtubule-Associated Proteins/genetics* ; Sirolimus/pharmacology*