Integration of metabolomics and network pharmacology technology to explain the effect mechanisms of Danggui Buxue decoction in vascular dementia.

Danggui Buxue decoction (DBD) is a traditional Chinese medicine herbal decoction that has a good therapeutic effect on vascular dementia (VaD). However, its pharmacodynamic substances and underlying mechanisms are ambiguous. The work aimed to decipher the pharmacodynamic substances and molecular mechanisms of DBD against VaD rats based on gas chromatography-mass spectrometry metabonomics, network pharmacology, molecular docking, and experimental verification. The results indicated that DBD significantly improved the learning abilities and cognitive impairment in the VaD rat model. Integration analysis of the metabolomics and network pharmacology approach revealed that DBD might primarily affect arachidonic acid (AA) and inositol phosphate metabolic pathways by regulating the platelet activation signaling pathways. Six core targets (TNF [tumor necrosis factor], IL-6 [interleukin 6], PTGS2 [prostaglandin-endoperoxide synthase 2], MAPK1, MAPK3, and TP53) in the platelet activation signaling pathways also had a good affinity to seven main active components (saponins, organic acids, flavonoids, and phthalides) of DBD through the verification of molecular docking. Enzyme-linked immunosorbent assay results (ELISA) showed that the levels of TNF, IL-6, PTGS2, thromboxane B2, and caspase-3 in the platelet activation signaling pathway can be regulated by DBD. Our results indicated that DBD treated VaD mainly by modulating the platelet activation signaling pathway, and AA and inositol phosphate metabolism.

Epitranscriptomic modifications in mesenchymal stem cell differentiation: advances, mechanistic insights, and beyond.

RNA modifications, known as the "epitranscriptome", represent a key layer of regulation that influences a wide array of biological processes in mesenchymal stem cells (MSCs). These modifications, catalyzed by specific enzymes, often termed "writers", "readers", and "erasers", can dynamically alter the MSCs' transcriptomic landscape, thereby modulating cell differentiation, proliferation, and responses to environmental cues. These enzymes include members of the classes METTL, IGF2BP, WTAP, YTHD, FTO, NAT, and others. Many of these RNA-modifying agents are active during MSC lineage differentiation. This review provides a comprehensive overview of the current understanding of different RNA modifications in MSCs, their roles in regulating stem cell behavior, and their implications in MSC-based therapies. It delves into how RNA modifications impact MSC biology, the functional significance of individual modifications, and the complex interplay among these modifications. We further discuss how these intricate regulatory mechanisms contribute to the functional diversity of MSCs, and how they might be harnessed for therapeutic applications. The review also highlights current challenges and potential future directions in the study of RNA modifications in MSCs, emphasizing the need for innovative tools to precisely map these modifications and decipher their context-specific effects. Collectively, this work paves the way for a deeper understanding of the role of the epitranscriptome in MSC biology, potentially advancing therapeutic strategies in regenerative medicine and MSC-based therapies.

Diverse Pathways of Engineered Nanoparticle-Induced NLRP3 Inflammasome Activation.

With the rapid development of engineered nanomaterials (ENMs) in biomedical applications, their biocompatibility and cytotoxicity need to be evaluated properly. Recently, it has been demonstrated that inflammasome activation may be a vital contributing factor for the development of biological responses induced by ENMs. Among the inflammasome family, NLRP3 inflammasome has received the most attention because it directly interacts with ENMs to cause the inflammatory effects. However, the pathways that link ENMs to NLRP3 inflammasome have not been thoroughly summarized. Thus, we reviewed recent findings on the role of major ENMs properties in modulating NLRP3 inflammasome activation, both in vitro and in vivo, to provide a better understanding of the underlying mechanisms. In addition, the interactions between ENMs and NLRP3 inflammasome activation are summarized, which may advance our understanding of safer designs of nanomaterials and ENM-induced adverse health effects.

PLEK2 promotes cancer stemness and tumorigenesis of head and neck squamous cell carcinoma via the c-Myc-mediated positive feedback loop.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent malignancies worldwide and is characterized by unfavorable prognosis, high lymph node metastasis and early recurrence. However, the molecular events regulating HNSCC tumorigenesis remain poorly understood. Therefore, uncovering the underlying mechanisms is urgently needed to identify novel and promising therapeutic targets for HNSCC. In this study, we aimed to explore the role of pleckstrin-2 (PLEK2) in regulating HNSCC tumorigenesis. METHODS: The expression pattern of PLEK2 and its clinical significance in HNSCC were determined by analyzing publicly assessable datasets and our own independent HNSCC cohort. In vitro and in vivo experiments, including cell proliferation, colony formation, Matrigel invasion, tumor sphere formation, ALDEFLUOR, Western blotting assays and xenograft mouse models, were used to investigate the role of PLEK2 in regulating the malignant behaviors of HNSCC cells. The underlying molecular mechanisms for the tumor-promoting role of PLEK2 were elucidated using co-immunoprecipitation, cycloheximide chase analysis, ubiquitination assays, chromatin immunoprecipitation-quantitative polymerase chain reaction, luciferase reporter assays and rescue experiments. RESULTS: The expression levels of PLEK2 mRNA and protein were significantly increased in HNSCC tissues, and PLEK2 overexpression was strongly associated with poor overall survival and therapeutic resistance. Additionally, PLEK2 was important for maintaining the proliferation, invasion, epithelial-mesenchymal transition, cancer stemness and tumorigenesis of HNSCC cells and could alter the cellular metabolism of the cancer cells. Mechanistically, PLEK2 interacted with c-Myc and reduced the association of F-box and WD repeat domain containing 7 (FBXW7) with c-Myc, thereby avoiding ubiquitination and subsequent proteasome-mediated degradation of c-Myc. Moreover, the c-Myc signaling activated by PLEK2 was important for sustaining the aggressive malignant phenotypes and tumorigenesis of HNSCC cells. c-Myc also directly bounded to the PLEK2 promoter and activated its transcription, forming a positive feedback loop. CONCLUSIONS: Collectively, these findings uncover a previously unknown molecular basis of PLEK2-enhanced c-Myc signaling in HNSCC, suggesting that PLEK2 may represent a promising therapeutic target for treating HNSCC.

[Effect and mechanism of testosterone level on inflammatory bone resorption in periodontitis with mice].

PURPOSE: To investigate the effect of testosterone level on inflammatory bone resorption in periodontitis with mice. METHODS: Forty-eight SD mice were randomly divided into unligated group, sham operation group, castration group, castration + testosterone group, 12 mice in each group. At 6 weeks after ligation, serum testosterone levels were measured, and alveolar bone loss (ABL) and alveolar bone absorption area were compared by hematoxylin - eosin staining and methylene blue staining. The expression of inflammatory cytokine messenger RNA(mRNA) in gingival tissue was measured by real-time fluorescence quantitative PCR. SPSS 20.0 software package was used to analyze the data. RESULTS: Serum testosterone level among four groups was the highest in the unligated group, followed by castration + testosterone group, sham operation group and castration group, with significant difference(P<0.05). The ABL of the castration + testosterone group was significantly larger than that of the unligated group, the sham operation group and the castration group(P<0.05). The ABL of the castration group was significantly smaller than that of the sham operation group (P<0.05). The alveolar bone resorption area of the castration + testosterone group was significantly larger than that of the unligated group, the sham operation group and the castration group(P<0.05). The alveolar bone resorption area of the castration group was significantly smaller than that of the sham operation group (P<0.05). Interleukin-1ß (IL-1ß) mRNA, interleukin-6(IL-6) mRNA and tumor necrosis factor-α(TNF-α) mRNA levels in gingival tissues of sham operation group, castration group and castration + testosterone group were significantly higher than the unligated group. The levels of interleukin-10(IL-10) mRNA in gingival tissues of sham operation group, castration group and castration + testosterone group were significantly lower than those in unligated group(P<0.05). The level of IL-1ß mRNA in gingival tissues among four groups was the the highest in the unligated group, followed by castration + testosterone group, sham operation group and castration group, with significant difference (P<0.05). Serum testosterone levels were positively correlated with ABL, alveolar bone resorption area, and IL-1ß (P<0.05). CONCLUSIONS: Periodontitis with mice have decreased testosterone levels, and long-term testosterone depletion can reduce inflammatory bone resorption in alveolar bone, which may be achieved by reducing the level of IL-1ß, indicating that reduction of the level of testosterone in periodontitis patients may be a new treatment target for alveolar bone resorption.

Identification and validation of an alternative splicing-based prognostic signature for head and neck squamous cell carcinoma.

Increasing evidence has demonstrated that changes in alternative splicing (AS) events are closely associated with the initiation and progression of cancer. However, the concrete role of AS in tumorigenesis of head and neck squamous cell carcinoma (HNSCC) is poorly known. In this study, we aimed to investigate the AS profile in HNSCC, and build up a robust AS-based prognostic signature for HNSCC. Our results revealed a total of 4068 overall survival (OS) associated AS events in the TCGA HNSCC cohort. The whole TCGA HNSCC cohort was randomly divided into discovery cohort and validation cohort. A prognostic signature including five AS events was developed with the discovery cohort based on the most significant OS-associated AS events. Then it was further successfully validated in the validation cohort. The AS-based risk signature was an independent prognostic indicator in both discovery cohort and validation cohort. This prognostic signature-based nomogram model showed excellent performance for predicting the OS of HNSCC. Splicing network analysis have identified the most correlated splicing factor-AS network in HNSCC. Collectively, we have constructed a robust AS-based prognostic signature which might contribute to improve the clinical outcome of HNSCC.

Biocompatibility of bone marrow mesenchymal cells on polyetheretherketone and titanium surfaces in vitro / 口腔疾病防治

Objective@#To compare the in vitro biocompatibility of bone marrow mesenchymal cells on polyetheretherketone (PEEK) and titanium (Ti) surfaces.@*Methods @#PEEK and Ti foils with thicknesses of 1 mm and diameters of 10 mm were prepared. First, bone marrow mesenchymal cells were separated and purified by the whole bone marrow adherent culture method in vitro. Then, osteogenesis-induced bone marrow mesenchymal cells were cultivated on the surfaces of the PEEK and Ti foils. Scanning electron microscopy (SEM), the Alamar Blue test, an alkaline phosphatase (ALP) kit and Alizarin Red staining were used to analyze calcium nodules and compare the adhesion, proliferation and osteogenic differentiation ability of bone marrow mesenchymal cells on the surfaces of the PEEK and Ti foils.@*Results @# ① The morphology of the bone marrow mesenchymal cells cultured on the PEEK and Ti foils at 1 h, 4 h and 24 h showed no significant differences. ② In the 1 h, 3 h, 1 d and 3 d cultures of the bone marrow mesenchymal cells inoculated on the surfaces of the foils, the number of living cells in the PEEK group was greater than that in the Ti group (P < 0.05). ③ In the 7 d and 14 d osteogenesis-induced cultures of the inoculated bone marrow mesenchymal cells, the ALP activity of the PEEK group cells was significantly greater than that of the Ti group cells (P < 0.05). ④ Semiquantitative analysis after Alizarin Red staining showed that the mineralization degree of the bone marrow mesenchymal cells induced by osteoblasts was greater in the PEEK group than in the Ti group (P < 0.05). @*Conclusion@#PEEK has better in vitro biocompatibility than Ti and can better promote cell adhesion, proliferation and osteogenic differentiation compared with Ti, and so it is expected to become a new dental implant material.