Magnetic graphene oxide nanocomposites induce cytotoxicity in ADSCs via GPX4 regulating ferroptosis.

Magnetic graphene oxide nanocomposites (MGO NPs) have been widely studied in biomedical applications. However, their cytotoxicity and underlying mechanisms remain unclear. In this study, the biosafety of MGO NPs was investigated, and the mechanism involved in ferroptosis was further explored. MGO can produce cytotoxicity in ADSCs, which is dependent on their concentration. Ferroptosis was involved in MGO NP-induced ADSC survival inhibition by increasing total ROS and lipid ROS accumulation as well as regulating the expression levels of ferroptosis-related genes and proteins. GPX4 played a critical role in the MGO NP-induced ADSC ferroptosis process, and overexpressing GPX4 suppressed ferroptosis to increase cell survival. This study provides a theoretical basis for the biosafety management of MGO NPs used in the field of biomedical treatment.

Bioinformatic analysis and verification of a lipid metabolism-related long noncoding RNA prognostic signature for head and neck squamous cell carcinoma.

PURPOSE: Both lipid metabolism reprogramming and lncRNAs exert effects on tumor development. We aimed to predict the prognosis of head and neck squamous cell carcinoma (HNSCC) based on lipid metabolism-related (LR)-lncRNAs. METHODS: LR-lncRNAs were determined from the RNA-ref profiles of HNSCC samples in The Cancer Genome Atlas (TCGA). The prognostic model was established by univariate Cox and Lasso regression analysis. Clinical relevance and predictive accuracy were investigated, and external validation was also performed in the Gene Expression Omnibus (GEO) cohort. Tumor immune infiltration and relevant functional analysis, including the association of autophagy with prognostic signatures, were conducted through single-sample gene set enrichment analysis (ssGSEA). The regulatory network of candidate LR-lncRNAs was investigated via coexpression, ceRNA and cis/trans acting interactions. Potential genes were selected through qRT-PCR analysis, and their effects on tumor biological activities and autophagic activity were explored after gene knockdown. RESULTS: A total of 222 LR-lncRNAs were identified. Among the 41 genes with prognostic significance, 17 lncRNAs were eligible for the risk model. Patients in the high-risk group had a poorer prognosis than those in the low-risk group, and the risk score was found to be positively associated with tumor microenvironment infiltration via multiple algorithms. Furthermore, improved prognosis was found in patients with high autophagic scores and low risk scores, and autophagy-related genes such as PINK1 and CCL2 showed significantly lower expression in the low-risk group. The expression of immune checkpoint genes such as CD28, CTLA4 and PDCD1 decreased dramatically in the high-risk group. The target genes of candidate lncRNAs were confirmed, such as ENO2 and PPAR-gamma. Furthermore, MIR4435-2HG was the most significantly overexpressed lncRNA in HNSCC cell lines and tumor samples, which could promote proliferation and migration and inhibit apoptosis. Additionally, MIR4435-2HG silencing activated autophagy by increasing LC3B expression. CONCLUSION: This study constructed an LR-lncRNA prognostic signature for HNSCC and indicated its relationships with tumor immunity and autophagy, which provides a promising future for LR-lncRNA-oriented prognostic tools and therapeutic targets.

Hydrazylpyridine salicylaldehyde-copper(II)-1,10-phenanthroline complexes as potential anticancer agents: synthesis, characterization and anticancer evaluation.

We synthesized and analyzed nine unique copper(II) hydrazylpyridine salicylaldehyde and 1,10-phenanthroline complexes, [Cu(L1a)(phen)] (Cugdupt1), [Cu(L2a)(phen)]·(CH3CN) (Cugdupt2), [Cu(L3a)(phen)] (Cugdupt3), [Cu(L4a)(phen)]·(CH3CN) (Cugdupt4), [Cu(L5a)(phen)] (Cugdupt5), [Cu(L6a)(phen)] (Cugdupt6), [Cu(L7a)(phen)] (Cugdupt7) [Cu(L8a)(phen)] (Cugdupt8) and [Cu(L9a)(phen)]·0.5(H2O) (Cugdupt9). We were motivated by the intriguing properties of the coupled ligands of hydrazylpyridine, salicylaldehyde, and 1,10-phenanthroline. The MTT assay demonstrated that Cugdupt1-Cugdupt9 have higher anticancer activity than L1H2-L9H2, phen and cisplatin on A549/DDP cancer cells (A549cis). Cugdupt1-Cugdupt9 were superior to cisplatin with IC50 values of 1.6-100.0 fold on A549cis cells (IC50(Cugdupt1-Cugdupt9) = 0.5-30.5 µM, IC50(cisplatin) = 61.5 ± 1.0 µM). However, Cugdupt1-Cugdupt9 had lower cytotoxicity toward the HL-7702 normal cells. Cugdupt1 and Cugdupt8 can induce reduction of mitochondrial respiratory chain complexes I/IV (MRCC-I/IV), mitophagy pathways, and eventually protein regulation and adenosine triphosphate (ATP) depletion in A549cis cells. The findings indicated that Cugdupt1 and Cugdupt8 caused cell death via both ATP diminution and mitophagy pathways. Finally, Cugdupt8 demonstrated high efficacy and no obvious cytotoxicity in A549 tumor-bearing mice. This study thus helps evaluate the potential of the hydrazylpyridine salicylaldehyde-copper(II)-1,10-phenanthroline compounds for cisplatin-resistant tumor therapy.

GPX8 deficiency-induced oxidative stress reprogrammed m6A epitranscriptome of oral cancer cells.

Glutathione peroxidase 8 (GPX8) is a key regulator of redox homoeostasis. Whether its antioxidant activity participates in the regulation of m6A modification is a crucial issue, which has important application value in cancer treatment. In this study, MeRIP-seq was used to explore the characteristics of transcriptome-wide m6A modification in GPX8-deficient oral cancer cells. Oxidative stress caused by the lack of GPX8 resulted in 1,279 hyper- and 2,287 hypo-methylated m6A peaks and 2,036 differentially expressed genes in GPX8-KO cells. Twenty-eight differentially expressed genes were related to the cell response to oxidative stress, and half of them changed their m6A modification. In GPX8-KO cells, m6A regulators IGF2BP2 and IGF2BP3 were upregulated, while FTO, RBM15, VIRMA, ZC3H13, and YTHDC2 were downregulated. After H2O2 treatment, the expression changes of RBM15, IGF2BP2, and IGF2BP3 were further enhanced. These data indicated that GPX8-mediated redox homoeostasis regulated m6A modification, thereby affecting the expression and function of downstream genes. This study highlights the possible significance of GPX8 and the corresponding m6A regulatory or regulated genes as novel targets for antioxidant intervention in cancer therapy.

Lack of GPX8 caused oxidative stress of oral cancer cells.Oxidative stress induced by GPX8 deficiency reprogrammed m⁶A epitranscriptome.GPX8 deletion­caused oxidative stress regulated expression of m⁶A regulatory genes.m⁶A modification of antioxidant genes is the adaptive response of cells to oxidative stress.

Graphdiyne Oxide-Mediated Photodynamic Therapy Boosts Enhancive T-Cell Immune Responses by Increasing Cellular Stiffness.

Purpose: Nanomaterial-based photodynamic therapy (PDT) has been commonly used for the treatment of cancerous tumors. Despite significant achievements made in this field, the intrinsic impact of nanomaterials-based PDT on the mechanical properties of oral squamous cell carcinoma (OSCC) cells is not entirely understood. Here, we used atomic force microscopy (AFM) to measure the stiffness of OSCC cells subjected to PDT in co-culture systems to evaluate the T cell-mediated cancer cell-killing effects. Methods: In this study, AFM was used to assess the stiffness of PDT-subjected cells. The phototoxicity of graphdiyne oxide (GDYO) was assessed using confocal laser scanning microscopy (CLSM), measurements of membrane cholesterol levels, and assessments of the F-actin cytoskeleton. A co-culture system was used to evaluate the effects of CD8+ T cells (cytotoxic T lymphocytes), demonstrating how PDT modulates the mechanical properties of cancer cells and activates T cell responses. The antitumor immunotherapeutic effect of GDYO was further evaluated in a murine xenograft model. Results: GDYO increased the mechanical stiffness of tumor cells and augmented T-cell cytotoxicity and inflammatory cytokine secretion (IFN-γ and TNF-α) under laser in vitro. Furthermore, GDYO-based PDT exerted inhibitory effects on OSCC models and elicited antitumor immune responses via specific cytotoxic T cells. Conclusion: These results highlight that GDYO is a promising candidate for OSCC therapy, shifting the mechanical forces of OSCC cells and breaking through the barriers of the immunosuppressive tumor microenvironment. Our study provides a novel perspective on nanomaterial-based antitumor therapies.

Efficacy of botulinum-A for nocturnal bruxism pain and the occurrence of bruxism events: a meta-analysis and systematic review.

The purpose of this study was to explore the treatment efficacy of botulinum-A (BTX-A) in nocturnal bruxism. Five electronic databases (PubMed, Web of Science, Cochrane, Embase and Clinical Trials) were searched to identify related randomised controlled trials up to September 1, 2020. Five evaluation indices were extracted, namely, the pain at rest and at chewing (PR and PC), the number of bruxism events (NBE) and the self-assessment by patients (SA), to assess the treatment efficacy of BTX-A in bruxism. All data analyses were conducted using Review Manager (Version 5.3; The Cochrane Collaboration, London, United Kingdom). Six studies were included in this review. The sample was composed of 148 participants. Compared with the placebo group, the BTX-A group showed the significantly improved the PR index scores (MD, 1.16 cm; 95%CI, 0.65 to 1.67 cm; p < 0.00001), slightly improved the PC index scores (SMD, 0.25; 95%CI -0.14 to 0.64; p = 0.21), and the NBEs were significantly decreased in the before-injection group compared with that in the after-injection group (MD, 1.72; 95%CI, 0.60 to 2.85; p = 0.003). The results of this study suggest that BTX-A possesses significant therapeutic efficiency for the relief of pain and events of bruxism. However, whether the events of bruxism would recur or rebound after botulinum toxin injection needs more follow-up clinical evidence.

Does the Lingual-Based Mucoperiosteal Flap Reduce Postoperative Morbidity Compared With the Buccal-Based Mucoperiosteal Flap After the Surgical Removal of Impacted Third Molars? A Meta-analysis Review.

PURPOSE: The lingual-based mucoperiosteal flap, a novel flap, was unclear about the effects on the prognosis of surgery for impacted mandibular third molars. This study aimed to compare the lingual- and buccal-based mucoperiosteal flaps with respect to postoperative responses and complications. MATERIALS AND METHODS: A systematic review with a meta-analysis was designed and the PubMed, Cochrane Library, EMBASE, and Web of Science databases and Google Scholar from January 1, 2000 to April 30, 2020 were searched for randomized clinical trials. The predictor variable was buccal- or lingual-based flap in the surgery, and the outcome variables were pain, swelling, trismus, operative time, and wound dehiscence. Other study variables were sex and retention depth of impacted teeth. RevMan 5.3 software was used for data analysis. Mean differences or standardized mean differences and risk ratios were computed to assess associations between 2 variables, where statistical significance was set at P < .05. RESULTS: Seven publications met the inclusion criteria, contributing 370 subjects who had 590 teeth removed to sample. The lingual-based flap failed to significantly reduce postoperative discomfort. However, subgroup analysis revealed that subjects who underwent comma flap (a type of lingual-based flap) surgeries complained of milder pain than those who underwent buccal-based flap surgeries on day 1 (mean difference = -1.18, 95% confidence interval [CI] [-1.53, -0.83], P < .001) and day 7 (mean difference = -1.80, 95% CI [-2.13, -1.48], P < .001) after surgery. Significant differences were also observed on days 1, 3, and 7 regarding postoperative swelling and trismus (P < .01). In addition, the lingual-based flap was reported to cause a significantly lower rate of wound dehiscence (relative risk = 0.46, 95% CI [0.30, 0.69], P = .0002). CONCLUSIONS: The lingual-based flap was associated with better primary wound closure in third molar removal. The comma flap, as a subtype, was preferable for relieving postoperative pain, swelling, and trismus over the buccal-based flap.

Knockout of miR-21-5p alleviates cartilage matrix degradation by targeting Gdf5 in temporomandibular joint osteoarthritis.

AIMS: The study aimed to determine whether the microRNA miR21-5p (MiR21) mediates temporomandibular joint osteoarthritis (TMJ-OA) by targeting growth differentiation factor 5 (Gdf5). METHODS: TMJ-OA was induced in MiR21 knockout (KO) mice and wild-type (WT) mice by a unilateral anterior crossbite (UAC) procedure. Mouse tissues exhibited histopathological changes, as assessed by: Safranin O, toluidine blue, and immunohistochemistry staining; western blotting (WB); and quantitative real-time polymerase chain reaction (RT-qPCR). Mouse condylar chondrocytes were transfected with a series of MiR21 mimic, MiR21 inhibitor, Gdf5 siRNA (si-GDF5), and flag-GDF5 constructs. The effects of MiR-21 and Gdf5 on the expression of OA related molecules were evaluated by immunofluorescence, alcian blue staining, WB, and RT-qPCR. RESULTS: UAC altered the histological structure and extracellular matrix content of cartilage in the temporomandibular joint (TMJ), and KO of MiR21 alleviated this effect (p < 0.05). Upregulation of MiR21 influenced the expression of TMJ-OA related molecules in mandibular condylar chondrocytes via targeting Gdf5 (p < 0.05). Gdf5 overexpression significantly decreased matrix metalloproteinase 13 (MMP13) expression (p < 0.05) and reversed the effects of MiR21 (p < 0.05). CONCLUSION: MiR21, which acts as a critical regulator of Gdf5 in chondrocytes, regulates TMJ-OA related molecules and is involved in cartilage matrix degradation, contributing to the progression of TMJ-OA. Cite this article: Bone Joint Res 2020;9(10):689-700.

Estrogen-Related Receptor γ Induces Angiogenesis and Extracellular Matrix Degradation of Temporomandibular Joint Osteoarthritis in Rats.

The main causes of cartilage destruction during temporomandibular joint osteoarthritis (TMJOA) are extracellular matrix degradation and angiogenesis, accompanied by an increased level of matrix-degrading enzymes and proangiogenic factors. Interleukin 6 and extracellular signal-regulated kinase (ERK) signaling pathways may play a critical role in these two processes simultaneously, but researchers have not clearly determined the mechanism. We hypothesized that estrogen-related receptor γ (ERRγ) is involved in both cartilage degeneration and angiogenesis in TMJOA. The interactions between ERRγ and the Mmp9 and Vegfa promoter regions were investigated using a chromatin immunoprecipitation (ChIP) assay. A chick embryo chorioallantoic membrane (CAM) assay was performed to investigate the inhibitory effects of U0126 and GSK5182 on angiogenesis. Western blotting, reverse transcription-quantitative PCR (RT-qPCR), immunofluorescence staining, toluidine blue staining, and transfection with cDNAs or small interfering RNAs (siRNAs) were performed on primary mandibular condylar chondrocytes (MCCs). Unilateral anterior crossbite-induced TMJOA models were established in rats, and Western blotting, RT-qPCR, immunohistochemistry, and Safranin O-Fast Green staining were performed to evaluate changes in vivo. ERK1/2 activated matrix metalloproteinase 9 (MMP9) and vascular endothelial growth factor A (VEGFA), which are involved in cartilage destruction, through ERRγ. Based on the ChIP assay results, ERRγ directly activated the transcription of the Mmp9 and Vegfa genes. In chick embryo CAM models, U0126 and GSK5182 significantly inhibited angiogenesis. In conclusion, ERRγ is a downstream transcription factor of ERK1/2, and its upregulation leads to extracellular matrix degradation and angiogenesis in TMJOA. This study identified a common factor between inflammation and vascularization in OA as well as a new therapeutic target for OA: ERRγ.