Association of gut microbiome and oral cavity cancer: A two sample mendelian randomization and case-control study.

INTRODUCTION: Considering the interconnectedness of the oral cavity and gut tract and the presence of abundant natural microbiota in both. We utilized Mendelian Randomization (MR) in a two-sample study to unveil the genetic causal impact of gut microbiota on the development of oral cavity cancer. MATERIALS & METHODS: The instrumental variables employed in this study consisted of single nucleotide polymorphisms (SNPs) that demonstrated a robust association with 211 distinct gut microbiota taxa, encompassing a sample size of 18,340 individuals. Our investigation sought to explore the potential causal relationship between these genetic variants and the incidence of oral cavity cancer. To accomplish this, we adopted a random effect inverse variance-weighted approach to analyze the causal effect. Additionally, sensitivity analyses were performed utilizing Cochran's Q tests, funnel plots, leave-one-out analyses, and MR-Egger intercept tests, to assess the robustness and validity of our findings. RESULTS: Five gut microbiota taxa (the family Prevotellaceae, the genus Alloprevotella, the genus Erysipelatoclostridium, the genus Parabacteroides, the genus Ruminococcus gauvreauii group) are predicted to play a causal role in promoting the initiation of the risk of oral cavity cancer. While the genus Christensenellaceae R 7 group, the genus Intestinimonas, the genus Ruminococcaceae, and the order Bacillales causally reduce the risk of oral cavity cancer. Furthermore, no significant evidence suggesting heterogeneity or pleiotropy was observed. DISCUSSION: The novel genetic causal effects of 211 gut microbiota taxa on oral cavity cancer are elucidated in this investigation, thus offering valuable insights for clinical interventions targeting oral cavity cancer.

UCHL1 alleviates apoptosis in chondrocytes via upregulation of HIF­1α­mediated mitophagy.

Stem cell­based tissue engineering has shown significant potential for rapid restoration of injured cartilage tissues. Stem cells frequently undergo apoptosis because of the prevalence of oxidative stress and inflammation in the microenvironment at the sites of injury. Our previous study demonstrated that stabilization of hypoxia­inducible factor 1α (HIF­1α) is key to resisting apoptosis in chondrocytes. Recently, it was reported that Ubiquitin C­terminal hydrolase L1 (UCHL1) can stabilize HIF­1α by abrogating the ubiquitination process. However, the effect of UCHL1 on apoptosis in chondrocytes remains unclear. Herein, adipose­derived stem cells were differentiated into chondrocytes. Next, the CRISPR activation (CRISPRa) system, LDN­57444 (LDM; a specific inhibitor for UCHL1), KC7F2 (a specific inhibitor for HIF­1α), and 3­methyladenine (a specific inhibitor for mitophagy) were used to activate or block UCHL1, HIF­1α, and mitophagy. Mitophagy, apoptosis, and mitochondrial function in chondrocytes were detected using immunofluorescence, TUNEL staining, and flow cytometry. Moreover, the oxygen consumption rate of chondrocytes was measured using the Seahorse XF 96 Extracellular Flux Analyzer. UCHL1 expression was increased in hypoxia, which in turn regulated mitophagy and apoptosis in the chondrocytes. Further studies revealed that UCHL1 mediated hypoxia­regulated mitophagy in the chondrocytes. The CRISPRa module was utilized to activate UCHL1 effectively for 7 days; endogenous activation of UCHL1 accelerated mitophagy, inhibited apoptosis, and maintained mitochondrial function in the chondrocytes, which was mediated by HIF­1α. Taken together, UCHL1 could block apoptosis in chondrocytes via upregulation of HIF­1α-mediated mitophagy and maintain mitochondrial function. These results indicate the potential of UCHL1 activation using the CRISPRa system for the regeneration of cartilage tissue.

Nanoparticles of Cerium-Doped Zeolitic Imidazolate Framework-8 Promote Soft Tissue Integration by Reprogramming the Metabolic Pathways of Macrophages.

Soft tissue integration around the abutment of implants is the basis of long-term retention of implants. Macrophages are an important component involved in the repair of soft tissue due to their crucial role in improving the biological structure of connective tissues by regulating the fiber synthesis, adhesion, and contraction of gingival fibroblasts. Recent studies have illustrated that cerium-doped zeolitic imidazolate framework-8 (Ce@ZIF-8) nanoparticles (NPs) can attenuate periodontitis via both antibacterial and anti-inflammatory effects. However, the effect of Ce@ZIF-8 NPs on soft tissue integration around the abutment is unknown. Herein, we first prepared Ce@ZIF-8 NPs by a one-pot synthesis. Then, we probed the regulatory effect of Ce@ZIF-8 NPs on macrophage polarization, and further experiments were performed to study the changes of fiber synthesis as well as adhesion and contraction of fibroblasts in the M2 macrophage environment stimulated by Ce@ZIF-8 NPs. Strikingly, Ce@ZIF-8 NPs can be internalized by M1 macrophages through macropinocytosis and caveolae-mediated endocytosis in addition to phagocytosis. By catalyzing hydrogen peroxide to produce oxygen, the mitochondrial function was remedied, while hypoxia inducible factor-1α was restrained. Then, macrophages were shifted from the M1 to M2 phenotype via this metabolic reprogramming pathway, provoking soft tissue integration. These results provide innovative insights into facilitating soft tissue integration around implants.

Repurposing Dihydroartemisinin to Combat Oral Squamous Cell Carcinoma, Associated with Mitochondrial Dysfunction and Oxidative Stress.

Oral squamous cell carcinoma (OSCC), with aggressive locoregional invasion, has a high rate of early recurrences and poor prognosis. Dihydroartemisinin (DHA), as a derivative of artemisinin, has been found to exert potent antitumor activity. Recent studies reported that DHA suppresses OSCC cell growth and viability through the regulation of reactive oxygen species (ROS) production and mitochondrial calcium uniporter. However, the mechanism underlying the action of DHA on OSCCs remains elusive. In the study, we observed that 159 genes were remarkably misregulated in primary OSCC tumors associated with DHA-inhibited pathways, supporting that OSCCs are susceptible to DHA treatment. Herein, our study showed that DHA exhibited promising effects to suppress OSCC cell growth and survival, and single-cell colony formation. Interestingly, the combination of DHA and cisplatin (CDDP) significantly reduced the toxicity of CDDP treatment alone on human normal oral cells (NOK). Moreover, DHA remarkably impaired mitochondrial structure and function, and triggered DNA damage and ROS generation, and activation of mitophagy. In addition, DHA induced leakage of cytochrome C and apoptosis-inducing factor (AIF) from mitochondria, elevated Bax/cleaved-caspase 3 expression levels and compromised Bcl2 protein expression. In the OSCC tumor-xenograft mice model, DHA remarkably suppressed tumor growth and induced apoptosis of OSCCs in vivo. Intriguingly, a selective mitophagy inhibitor Mdivi-1 could significantly reinforce the anticancer activity of DHA treatment. DHA and Mdivi-1 can synergistically suppress OSCC cell proliferation and survival. These data uncover a previously unappreciated contribution of the mitochondria-associated pathway to the antitumor activity of DHA on OSCCs. Our study shed light on a new aspect of a DHA-based therapeutic strategy to combat OSCC tumors.

Controlled and Sequential Delivery of Stromal Derived Factor-1 α (SDF-1α) and Magnesium Ions from Bifunctional Hydrogel for Bone Regeneration.

Bone healing is a complex process that requires the participation of cells and bioactive factors. Stromal derived factor-1 α (SDF-1α) and magnesium ions (Mg2+) both are significant bioactive factors for cell recruitment and osteogenesis during bone regeneration. Thus, a bifunctional hydrogel containing a sequential delivery system is fabricated to improve osteogenesis. During sequential delivery of the hydrogel, SDF-1α is predominantly released at the early stage of bone mesenchymal stem cells (BMSCs) recruitment, while Mg2+ are constantly delivered at a later stage to improve osteogenic differentiation of recruited cells. In addition, due to the early release of SDF-1α, the hydrogel showed strong BMSCs recruitment and proliferation activity. Mg2+ can not only induce up-regulation of osteogenic gene expression in vitro, but also promote bone tissue and angiogenesis in vivo. Taken together, the injection of xanthan gum-polydopamine crosslinked hydrogel co-loading SDF-1α and Mg2+ (XPMS hydrogel) provides a novel strategy to repair bone defects.

Scaffold 3D-Printed from Metallic Nanoparticles-Containing Ink Simultaneously Eradicates Tumor and Repairs Tumor-Associated Bone Defects.

Bone metastasis occurs in about 70% of breast cancer patients. The surgical resection of metastatic tumors often leads to bone erosion and destruction, which greatly hinders the treatment and prognosis of breast cancer patients with bone metastasis. Herein, a bifunctional scaffold 3D-printed from nanoink is fabricated to simultaneously eliminate the tumor cells and repair the tumor-associated bone defects. The metallic polydopamine (PDA) nanoparticles (FeMg-NPs) may effectively load and sustainably release the metal ions Fe3+ and Mg2+ in situ. Fe3+ exerts a chemodynamic therapy to synergize with the photothermal therapy induced by PDA with effective photothermal conversion under NIR laser, which efficiently eliminates the bone-metastatic tumor. Meanwhile, the sustained release of osteoinductive Mg2+ from the bony porous 3D scaffold enhances the new bone formation in the bone defects. Taken together, the implantation of scaffold (FeMg-SC) 3D-printed from the FeMg-NPs-containing nanoink provides a novel strategy to simultaneously eradicate bone-metastatic tumor and repair the tumor-associated bone defects.

Cadmium exposure induces osteoporosis through cellular senescence, associated with activation of NF-κB pathway and mitochondrial dysfunction.

Cadmium (Cd) is a heavy metal toxicant as a common pollutant derived from many agricultural and industrial sources. The absorption of Cd takes place primarily through Cd-contaminated food and water and, to a significant extent, via inhalation of Cd-contaminated air and cigarette smoking. Epidemiological data suggest that occupational or environmental exposure to Cd increases the health risk for osteoporosis and spontaneous fracture such as itai-itai disease. However, the direct effects and underlying mechanism(s) of Cd exposure on bone damage are largely unknown. We used primary bone marrow-derived mesenchymal stromal cells (BMMSCs) and found that Cd significantly induced BMMSC cellular senescence through over-activation of NF-κB signaling pathway. Increased cell senescence was determined by production of senescence-associated secretory phenotype (SASP), cell cycle arrest and upregulation of p21/p53/p16INK4a protein expression. Additionally, Cd impaired osteogenic differentiation and increased adipogenesis of BMMSCs, and significantly induced cellular senescence-associated defects such as mitochondrial dysfunction and DNA damage. Sprague-Dawley (SD) rats were chronically exposed to Cd to verify that Cd significantly increased adipocyte number, and decreased mineralization tissues of bone marrow in vivo. Interestingly, we observed that Cd exposure remarkably retarded bone repair and regeneration after operation of skull defect. Notably, pretreatment of melatonin is able to partially prevent Cd-induced some senescence-associated defects of BMMSCs including mitochondrial dysfunction and DNA damage. Although Cd activated mammalian target of rapamycin (mTOR) pathway, rapamycin only partially ameliorated Cd-induced cell apoptosis rather than cellular senescence phenotypes of BMMSCs. In addition, a selective NF-κB inhibitor moderately alleviated Cd-caused the senescence-related defects of the BMMSCs. The study shed light on the action and mechanism of Cd on osteoporosis and bone ageing, and may provide a novel option to ameliorate the harmful effects of Cd exposure.

Combined inhibition of RNA polymerase I and mTORC1/2 synergize to combat oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is the major cause of morbidity and mortality in head and neck cancer patients worldwide. This malignant disease is challenging to treat because of the lack of effective curative strategies and the high incidence of recurrence. This study aimed to investigate the efficacy of a single and dual approach targeting ribosome biogenesis and protein translation to treat OSCC associated with the copy number variation (CNV) of ribosomal DNA (rDNA). Here, we found that primary OSCC tumors frequently exhibited a partial loss of 45S rDNA copy number and demonstrated a high susceptibility to CX5461 (a selective inhibitor of RNA polymerase I) and the coadministration of CX5461 and INK128 (a potent inhibitor of mTORC1/2). Combined treatment displayed the promising synergistic effects that induced cell apoptosis and reactive oxygen species (ROS) generation, and inhibited cell growth and proliferation. Moreover, INK128 compromised NHEJ-DNA repair pathway to reinforce the antitumor activity of CX5461. In vivo, the cotreatment synergistically suppressed tumor growth, triggered apoptosis and strikingly extended the survival time of tumor-bearing mice. Additionally, treatment with the individual compounds and coadministration appeared to reduce the incidence of enlarged inguinal lymph nodes. Our study supports that the combination of CX5461 and INK128 is a novel and efficacious therapeutic strategy that can combat this cancer and that 45S rDNA may serve as a useful indicator to predict the efficacy of this cotreatment.

Promoted Bone Regeneration by 3D-Printed Porous Scaffolds with the Synergy of a Nanotopological Morphology and Amino Modification.

Three-dimensional (3D)-printed scaffolds have great advantages for bone repair, and the combination of physical and chemical modifications of the surface can improve deficient biological properties to promote bone regeneration. In this study, a nanotopological morphology and an amino group were introduced into scaffold surfaces in sequence by alkaline solution and amination, respectively. The surface properties and the ability for osteogenic induction were investigated. The nanotopological morphology of the surface slightly enhanced the hydrophilic property of the material, while amination obviously increased the hydrophilicity of the surface. The aminated surface improved cell adhesion and proliferation, while the nanotopological morphology was able to facilitate the spread of stem cells, pseudopod extension, and osteogenic differentiation by changing the cell skeleton. The study confirmed that a nanotopological morphology and an amino group can play synergistic roles in improving the osteogenic efficiency and hydrophilicity, which was also confirmed in vivo by showing that effective surface modification of polylactic acid scaffolds enhanced high-quality bone formation, thus demonstrating great potential for clinical applications. The results indicate that scaffolds with the synergy of a nanotopological morphology and amino modification improve the osteogenic induction ability of scaffolds.

In Vitro and Clinical Studies of Gene Therapy with Recombinant Human Adenovirus-p53 Injection for Malignant Melanoma.

Malignant melanoma is an aggressive tumor with high fatality rates and poor prognosis, mainly due to the lack of efficient treatment methods. The present study investigated the potential antitumor effects of recombinant adenovirus p53 (rAd-p53) on human malignant melanoma. The optimal viral titer on a human malignant melanoma (A-375) cell line was determined for the rAd-p53 treatment. The invasive abilities, apoptosis, variations in the cell cycle, and molecular expression levels of A-375 cells were detected after infection by rAd-p53. A tumor growth curve and hematoxylin and eosin staining were carried out for experiments in nude mice. Twenty-one patients with malignant melanoma were evaluated, including 12 cases without gene therapy and nine cases with rAd-p53 gene therapy. The overall survival rate and the median survival time were analyzed between the two groups of patients. When the multiplicity of infection was 100, the cells showed the best transfection efficiency. The invasive ability, apoptosis, cycle changes of the cells, and the expression of the p53, p21, and Bax genes and proteins were significantly changed in the experimental group. In nude mice, the tumor growth curve and the tumor size in the experimental group were significantly smaller than those of the control group. Hematoxylin and eosin staining revealed tumor metastasis in the blank group and the control group but not in the experimental group. Between the two groups of patients, the median survival of the gene therapy group (38 months) was greater than that of the group without gene therapy (27 months). In this study, high expression of the p53 gene could regulate the gene expression and reduce the invasive and metastatic abilities of the tumor cells. Furthermore, rAd-p53 effectively improved the survival of patients with malignant melanoma. Therefore, rAd-p53 may be a potential treatment method for human malignant melanoma.