南方医科大学学报杂志最新文献

Objective: To investigate the effect of human colorectal fibroblast (CCD-18Co)-conditioned medium (CCD18-Co-CM) on biological behaviors of colorectal cancer (CRC) cells and explore the possible molecular mechanisms.

Methods: Real-time cellular analysis (RTCA), clone formation assay and wound healing assay were used to analyze the changes in proliferation, clone formation, and migration abilities of CRC cell lines HCT116 and Caco-2 treated with CCD18-Co-CM. Western blotting was used to detect the changes in ATK, ERK and STAT3 signaling pathways in the CRC cells activated by CCD18-Co-CM. The effect of CCD18-Co-CM on spheroidization ability of the cells was assessed with sphere-formation assay, and the changes in expressions of CRC stemness markers were detected using RT-PCR.

Results: CCD-18Co-CM significantly promoted proliferation, colony formation, and migration of HCT116 and Caco-2 cells, enhanced sphere-forming ability and expressions of CRC stemness markers, and increased ERK phosphorylation in the cells. Treatment with SCH772984 effectively inhibited CCD-18Co-CM-induced ERK signaling pathway activation, suppressed the malignant phenotype, and lowered the sphere-forming ability and expression of stemness markers of the two CRC cells.

Conclusion: Colorectal fibroblasts promote malignant phenotype of CRC cells by activating the ERK signaling pathway.

Objective: To investigate whether quercetin inhibits pyroptosis of mouse fibroblast NIH-3T3 cells by regulating the NLRP3/caspase-1/GSDMD signaling pathway.

Methods: NIH-3T3 cells were treated with quercetin or MCC950 (a specific inhibitor of NLRP3) before stimulation with lipopolysaccharide (LPS) and ATP to induce cell pyroptosis. The optimal quercetin concentration and duration were screened using the CCK-8assay after testing various concentrations and times. Morphological changes of the treated cells was observed, and the levels of IL-18 and IL-1β in the cell culture supernatant were detected with ELISA; the protein expressions of NLRP3, cleaved caspase-1, and GSDMD-N and the mRNA levels of NLRP3, caspase-1 and GSDMD were detected using Western blotting and qRT-PCR. The changes in cell pyroptosis were examined with TUNEL staining and LDH release assay.

Results: The CCK-8 assay indicated that 24-hour treatment with 20 μmol/L quercetin yielded the most favorable results. LPS and ATP stimulation of NIH-3T3 cells induced obvious swelling, cell membrane rupture and leakage of cell contents, significantly increased IL-18 and IL-1β levels, and enhanced protein expressions of NLRP3, cleaved caspase-1 and GSDMD-N and mRNA levels of NLRP3, caspase-1 and GSDMD. LPS and ATP stimulation also caused a significant increment of TUNEL-positive cell counts and LDH release in NIH-3T3 cells. Treatment with quercetin or MCC950 significantly reduced cell pyroptosis induced by LPS and ATP, lowered the concentrations of IL-18 and IL-1β, decreased the expression levels of NLRP3, caspase-1/cleaved caspase-1, GSDMD/GSDMD-N, and reduced the number of TUNEL-positive cells and LDH release.

Conclusion: Quercetin suppresses pyroptosis of mouse fibroblasts stimulated with LPS and ATP and reduces secretion of inflammatory cytokines by inhibiting the NLRP3/caspase-1/GSDMD pathway.

Objective: To investigate the mechanism mediating the regulatory effect of lncRNA MAGI2-AS3 on cisplatin (DDP) resistance in non-small cell lung cancer (NSCLC).

Methods: MAGI2-AS3 and miR-1269a expression levels were detected by qRT-PCR in DDP-sensitive lung cancer cell lines (A549 and H1299) and their resistant counterparts (A549/DDP and H1299/DDP). In A549 and H1299 cells with MAGI2-AS3 silencing and A549/DDP and H1299/DDP cells overexpressing MAGI2-AS3, the effects of 20 μmol/L DDP on cell viability and apoptosis were examined with CCK-8 assay, colony formation assay, flow cytometry and Western blotting, and the changes in epithelial-mesenchymal transition (EMT) were assessed with wound healing and Transwell assays. The interaction between MAGI2-AS3, miR-1269a and PTEN was predicted using GEPIA, StarBase and miRDB and verified with luciferase reporter gene assay and radioimmunoprecipitation (RIP) assay. A miR-1269a mimic and pcDNA3.1-PTEN plasmid were used to perform the rescue assay.

Results: MAGI2-AS3 expression was significantly downregulated in lung cancer tissues (P < 0.05) in association with a poor prognosis (P < 0.05). In the two DDP-resistant lung cancer cell lines, MAGI2-AS3 expression was significantly lowered as compared with the sensitive cells. Silencing MAGI2-AS3 significantly enhanced cell viability and promoted EMT of A549 and H1299 cells irrespective of DDP treatment, and also decreased DDP-induced apoptosis of the cells. In A549/DDP and H1299/DDP cells, MAGI2-AS3 overexpression strongly repressed cell viability and EMT irrespective of DDP treatment and promoted DDP-induced cell apoptosis. Luciferase reporter gene and RIP assays confirmed the binding of MAGI2-AS3 with miR-1269a and the binding of miR-1269a with 3 '-UTR domain of PTEN. The rescue assay demonstrated that MAGI2-AS3 acted as a sponge for miR-1269a to promote PTEN expression and downregulate AKT phosphorylation, thus inhibiting EMT and promoting DDP-induced apoptosis of A549/DDP cells.

Conclusion: MAGI2-AS3 enhances DDP sensitivity of NSCLC by targeted regulation of the miR-1269a/PTEN/AKT signaling axis.

Objective: To observe the effects of restricted and high-fat diets on behavioral changes of wild-type (Adrb1^+/+) and transgenic mice carrying Adrb1-A187V mutation (Adrb1^+/m) with short sleep durations.

Methods: Adrb1^+/+ and Adrb1^+/m C57BL/6 mice were randomized into normal chow group (25 Adrb1^+/+ and 26 Adrb1^+/m mice for behavioral monitoring), odor retention fasting group (17 Adrb1^+/+ and 19 Adrb1^+/m mice for behavioral monitoring; 6 Adrb1^+/+ mice and 6 Adrb1^+/m mice for EEG/EMG monitoring), absolute fasting group (6 Adrb1^+/+ and 4-5 Adrb1^+/m mice for behavioral monitoring; 6 Adrb1^+/+ and 6 Adrb1^+/m mice for EEG/EMG monitoring), and high-fat diet group (6 Adrb1^+/+ and 7 Adrb1^+/m mice for behavioral monitoring; 6 Adrb1^+/+ and 6 Adrb1^+/m mice for EEG/EMG monitoring). Electrodes for EEG and muscle activity monitoring were implanted on the skulls of the mice. After 24 h of odor retention fasting, absolute fasting, or high-fat feeding, the mice were observed for behavioral changes adapted to diet changes.

Results: In odor retention fasting experiment, Adrb1^+/m mice exhibited more stable fluctuations of activities with mildly reduced movement and prolonged sleep duration, indicating enhanced starvation resistance. In absolute fasting experiment, Adrb1^+/m mice showed significantly increased nighttime water intake, improved rhythmicity in water intake (frequent intakes in small amounts), and increased duration of non-rapid eye movement sleep (NREM). In the high-fat diet experiment, Adrb1^+/m mice showed higher levels of activity with increased instances of nighttime rearing, longer movement distances, and increased rapid eye movement sleep during daytime.

Conclusion: Adrb1^+/m mice can quickly respond to environmental changes and under restricted dietary conditions, they can conserve energy by increasing sleep to maintain energy homeostasis but show higher levels of activity under high-fat dietary conditions.

Objective: To establish a predictive model for survival outcomes of glioma patients based on both brain radiomics features from preoperative MRI multi-sequence images and clinical features.

Methods: We retrospectively analyzed the MRI images and clinical data of 388 glioma patients and extracted the radiomics features from the peritumoral edema zone, tumor core, and whole tumor on T1, T2, and T1-weighted contrast-enhanced (T1CE) and fluid attenuated inversion recovery (FLAIR) sequences. The cases were divided into a training set (271 cases) and a test set (117 cases). Random survival forest algorithms were used to select the radiomics features associated with overall survival (OS) in the training set to construct a radiomic score (Rad-score), based on which the patients were classified into high- and low-risk groups for Kaplan-Meier survival analysis. Cox proportional hazard regression models for the 3 different tumor zones were constructed, and their performance for predicting 1- and 3-year survival rates was evaluated using 5-fold cross-validation and AUC analysis followed by external validation using data from another 10 glioma patients. The best-performing model was used for constructing a nomogram for survival predictions.

Results: Five radiomics features from the tumor core, 7 from the peritumoral edema zone, and 5 from the whole tumor were selected. In both the training and test sets, the high- and low-risk groups had significantly different OS (P < 0.05), and age, IDH status and Rad-score were independent factors affecting OS. The combined model showed better performance than the Rad-score model with AUCs for 1-year and 3-year survival prediction of 0.750 and 0.778 in the training set, 0.764 and 0.800 in the test set, and 0.938 and 0.917 in external validation, respectively.

Conclusion: The predictive model combining preoperative multi-modal MRI radiomics features and clinical features can effectively predict survival outcomes of glioma patients.

Objective: To investigate the mechanism behind the protective effects of gastrodin against microglia-mediated inflammatory responses following hypoxic-ischemic brain damage (HIBD) in neonatal mice.

Methods: Thirty-six 10-day-old C57BL/6J mice were randomized into sham-operated group, HIBD (induced by ligation of the left common carotid artery followed by hypoxia for 40 min) group, and HIBD with gastrodin treatment groups (n=12). In gastrodin treatment group, 100 mg/kg gastrodin was injected intraperitoneally 1 h before and at 2 and 12 h after hypoxia. After the treatments, the expressions of CCR5, AKT, p-AKT, and TNF-α and the co-expression of IBA1 and CCR5 in the corpus callosum of the mice were detected with Western blotting and immunofluorescence double staining. In a BV2 microglial cell model of oxygen-glucose deprivation (OGD), the effects of pretreatment with gastrodin and Maraviroc (an CCR5 antagonist) on protein expressions of CCR5, AKT, p-AKT, TNF-α and IL-1β were evaluated using Western blotting and immunofluorescence double staining.

Results: The neonatal mice with HIBD showed significantly increased expressions of CCR5 and TNF-α with lowered p-AKT expression in the brain tissues, and GAS treatment obviously reversed these changes. HIBD also significantly increased the co-expression of IBA1 and CCR5 in the corpus callosum of the mice, which was obviously lowered by gastrodin treatment. In BV2 cells, OGD significantly increased the expressions of CCR5, TNF-α, and IL-1β and decreased the expression of p-AKT, and these changes were inhibited by treatment with gastrodin, Maraviroc or their combination; the inhibitory effect of the combined treatment did not differ significantly from that of gastrodin or Maraviroc alone.

Conclusion: Gastrodin can produce neuroprotective effects in neonatal mice with HIBD by inhibiting inflammatory cytokine production and activate AKT phosphorylation via inhibiting CCR5.

Objective: To investigate whether cisplatin induces tumor necrosis factor-α (TNF-α) secretion in human head and neck squamous cell carcinoma (HNSCC) cells to trigger RIP1/RIP3/MLKL-dependent necroptosis of the cells.

Methods: HNSCC cell lines HN4 and SCC4 treated with cisplatin (CDDP) or the combined treatment with CDDP and z-VAD-fmk (a caspase inhibitor) or Nec-1 (a necroptosis inhibitor) for 24 h were examined for changes in cell viability using CCK8 assay and expressions of caspase-8 and necroptosis pathway proteins (RIP1/RIP3/MLKL) using Western blotting. The changes in migration of the cells were assessed with cell scratch assay, and the expressions of epithelial-mesenchymal transition (EMT) marker proteins N-cadherin, vimentin, and E-cadherin as well as the expressions of NF-κB (p65) and TNF-α were detected with Western blotting.

Results: The IC₅₀ of cisplatin was 10 μg/mL in HN4 cells and 15 μg/mL in SCC4 cells. Cisplatin treatment significantly decreased the expressions of caspase-8, N-cadherin and vimentin and increased the expressions of Ecadherin, the necroptosis pathway proteins (RIP1/RIP3/MLKL), TNF-α, and NF-κB (p65), and these changes were obviously inhibited by treatment with Nec-1. Cisplatin stimulation also significantly lowered migration of the cells, and this inhibitory effect was strongly attenuated by Nec-1 treatment.

Conclusion: Cisplatin activates nuclear factor-κB signaling in HNSCCs to promote TNF-α autocrine and induce RIP1/RIP3/MLKL-dependent necroptosis, thus leading to inhibition of cell proliferation.

Methods: To investigate how the timing of cooling therapy affects organ injuries in rats with exertional heat stroke (EHS) and explore the possible mechanisms.

Methods: A total of 60 adult male Wistar rat models of EHS were randomized into model group without active cooling after modeling, immediate cooling group with cold water bath immediately after modeling, delayed cooling groups with cold water bath at 5, 15 and 30 min after modeling, with another 12 mice without EHS as the normal control group. The changes in core body temperature of the mice were recorded and the cooling rate was calculated. After observation for 24 h, the mice were euthanized and blood samples were collected for detection of interleukin-1β (IL-1β), IL-2, IL-4, IL-6, IL-10, and interferon-γ, followed by pathological examination of the vital organs. The rats that died within 24 h were immediately dissected for examination.

Results: The number of deaths of the model rats within 24 h increased significantly with the time of delay of cooling treatment. The delay of cooling was positively correlated (r=0.996, P=0.004) while the cooling rate negatively correlated with the mortality rate (r=-0.961, P=0.009). The inflammatory cytokine levels presented with different patterns of variations among the cooling intervention groups. All the rat models of EHS had significant organ damages characterized mainly by epithelial shedding, edema, effusion, and inflammatory cell infiltration, and brain and renal injuries reached the peak level at 24 h after EHS.

Conclusion: EHS causes significant nonspecific pathologies of varying severities in the vital organs of rats, and the injuries worsen progressively with the delay of cooling. There is a significant heterogeneity in changes of serum inflammatory cytokines in rats with different timing of cooling intervention following EHS.

Objective: To investigate the molecular mechanism of lipid metabolism disorder in mouse spleen tissues due to high-altitude hypoxia.

Methods: Ten C57BL/6 male mice were randomly divided into normoxia group (maintained at an altitude of 400 m) and high-altitude hypoxia group (maintained at 4200 m) for 30 days (n=5). Lipidomics and metabolomics analyses of the spleen tissue of the mice were conducted using liquid chromatography-mass spectrometry (LC-MS) to identify the differential metabolites, which were further analyzed by KEGG enrichment and pathway analyses, and the differential genes were screened through transcriptome sequencing. Bioinformatics analysis was conducted to identify the upstream target genes of the differential metabolites in specific metabolic pathways. RT-qPCR and Western blotting were used to detect mRNA expressions of 11β-hydroxysteroid dehydrogenase 1 (HSD11B1), steroid 5α reductase 1 (SRD5A1), prostaglandin-endoperoxide synthase 1 (PTGS1), hematopoietic prostaglandin D synthetase (HPGDS), xanthine dehydrogenase (XDH), purine nucleoside phosphorylase (PNP), hypoxanthine guanine-phosphoribosyltransferase (HPRT) and extracellular 5'-nucleotidase (NT5E) and protein expressions of HSD11B1, SRD5A1, XDH, PNP and HPRT in the mouse spleens.

Results: We identified a total of 41 differential lipid metabolites in the mouse spleens, and these metabolites and the differential genes were enriched in steroid hormone biosynthesis, arachidonic acid metabolism, and purine metabolism pathways. Compared to the mice kept in normoxic conditions, the mice exposed to high-altitude hypoxia showed significantly upregulated expressions of adrenosterone, androsterone, prostaglandin D2, prostaglandin J2, xanthine, xanthosine, and uric acid in the spleen with also changes in the expression levels of HSD11B1, SRD5A1, PTGS1, HPGDS, XDH, PNP, HPRT, and NT5E.

Conclusion: High-altitude hypoxia can result in lipid metabolism disorder in mouse spleen tissue by affecting steroid hormone biosynthesis, arachidonic acid metabolism, and purine metabolism pathways.

Objective: To propose a dual-domain CBCT reconstruction framework (DualSFR-Net) based on generative projection interpolation to reduce artifacts in sparse-view cone beam computed tomography (CBCT) reconstruction.

Methods: The proposed method DualSFR-Net consists of a generative projection interpolation module, a domain transformation module, and an image restoration module. The generative projection interpolation module includes a sparse projection interpolation network (SPINet) based on a generative adversarial network and a full-view projection restoration network (FPRNet). SPINet performs projection interpolation to synthesize full-view projection data from the sparse-view projection data, while FPRNet further restores the synthesized full-view projection data. The domain transformation module introduces the FDK reconstruction and forward projection operators to complete the forward and gradient backpropagation processes. The image restoration module includes an image restoration network FIRNet that fine-tunes the domain-transformed images to eliminate residual artifacts and noise.

Results: Validation experiments conducted on a dental CT dataset demonstrated that DualSFR-Net was capable to reconstruct high-quality CBCT images under sparse-view sampling protocols. Quantitatively, compared to the current best methods, the DualSFR-Net method improved the PSNR by 0.6615 and 0.7658 and increased the SSIM by 0.0053 and 0.0134 under 2-fold and 4-fold sparse protocols, respectively.

Conclusion: The proposed generative projection interpolation-based dual-domain CBCT sparse-view reconstruction method can effectively reduce stripe artifacts to improve image quality and enables efficient joint training for dual-domain imaging networks in sparse-view CBCT reconstruction.