Identification of receptors and factors associated with human coronaviruses in the oral cavity using single-cell RNA sequencing.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) ravaged the world, and Coronavirus Disease 2019 (COVID-19) exhibited highly prevalent oral symptoms that had significantly impacted the lives of affected patients. However, the involvement of four human coronavirus (HCoVs), namely SARS-CoV-2, SARS-CoV, MERS-CoV, and HCoV-229E, in oral cavity infections remained poorly understood. We integrated single-cell RNA sequencing (scRNA-seq) data of seven human oral tissues through consistent normalization procedure, including minor salivary gland (MSG), parotid gland (PG), tongue, gingiva, buccal, periodontium and pulp. The Seurat, scDblFinder, Harmony, SingleR, Ucell and scCancer packages were comprehensively used for analysis. We identified specific cell clusters and generated expression profiles of SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFs) in seven oral regions, providing direction for predicting the tropism of four HCoVs for oral tissues, as well as for dental clinical treatment. Based on our analysis, it appears that various SCARFs, including ACE2, ASGR1, KREMEN1, DPP4, ANPEP, CD209, CLEC4G/M, TMPRSS family proteins (including TMPRSS2, TMPRSS4, and TMPRSS11A), and FURIN, are expressed at low levels in the oral cavity. Conversely, BSG, CTSB, and CTSL exhibit enrichment in oral tissues. Our study also demonstrates widespread expression of restriction factors, particularly IFITM1-3 and LY6E, in oral cells. Additionally, some replication, assembly, and trafficking factors appear to exhibit broad oral tissues expression patterns. Overall, the oral cavity could potentially serve as a high-risk site for SARS-CoV-2 infection, while displaying a comparatively lower degree of susceptibility towards other HCoVs (including SARS-CoV, MERS-CoV and HCoV-229E). Specifically, MSG, tongue, and gingiva represent potential sites of vulnerability for four HCoVs infection, with the MSG exhibiting a particularly high susceptibility. However, the expression patterns of SCARFs in other oral sites demonstrate relatively intricate and may only be specifically associated with SARS-CoV-2 infection. Our study sheds light on the mechanisms of HCoVs infection in the oral cavity as well as gains insight into the characteristics and distribution of possible HCoVs target cells in oral tissues, providing potential therapeutic targets for HCoVs infection in the oral cavity.

Antimicrobial agent chloroxylenol targets ß­catenin­mediated Wnt signaling and exerts anticancer activity in colorectal cancer.

Chloroxylenol is the active ingredient of the antibacterial agent Dettol. The anticancer effect and underlying mechanisms of this compound and other common antimicrobial agents have not been clearly elucidated. In the present study, the effects of chloroxylenol, benzalkonium chloride, benzethonium chloride, triclosan and triclocarban on ß­catenin­mediated Wnt signaling in colorectal cancer were evaluated using the SuperTOPFlash reporter assay. It was demonstrated that chloroxylenol, but not the other antimicrobial agents tested, inhibited the Wnt/ß­catenin signaling pathway by decreasing the nuclear translocation of ß­catenin and disrupting ß­catenin/T­cell factor 4 complex, which resulted in the downregulation of the Wnt target genes Axin2, Survivin and Leucine­rich G protein­coupled receptor­5. Chloroxylenol effectively inhibited the viability, proliferation, migration and invasion, and sphere formation, and induced apoptosis in HCT116 and SW480 cells. Notably, chloroxylenol attenuated the growth of colorectal cancer in the MC38 cell xenograft model and inhibited organoid formation by the patient­derived cells. Chloroxylenol also demonstrated inhibitory effects on the stemness of colorectal cancer cells. The results of the present study demonstrated that chloroxylenol could exert anti­tumor activities in colorectal cancer by targeting the Wnt/ß­catenin signaling pathway, which provided an insight into its therapeutic potential as an anticancer agent.

Isoxazole 9 (ISX9), a small molecule targeting Axin, activates Wnt/ß-catenin signalling and promotes hair regrowth.

BACKGROUND AND PURPOSE: Isoxazole 9 (ISX9) is a neurogenesis-promoting small molecule compound that can up-regulate the expression of NeuroD1 and induce differentiation of neuronal, cardiac and islet endocrine progenitors. So far, the molecular mechanisms underlying the action of ISX9 still remain elusive. EXPERIMENTAL APPROACH: To identify a novel agonist of the Wnt/ß-catenin, a cell-based SuperTOPFlash reporter system was used to screen known-compound libraries. An activation effect of ISX9 on the Wnt/ß-catenin pathway was analysed with the SuperTOPFlash or SuperFOPFlash reporter system. Effects of ISX9 on Axin1/LRP6 interaction were examined using a mammalian two-hybrid system, co-immunoprecipitation, microscale thermophoresis, emission spectra and mass spectrometry assays. The expression of Wnt target and stemmness marker genes were evaluated with real-time PCR and immunoblotting. In vivo hair regeneration abilities of ISX9 were analysed by immunohistochemical staining, real-time PCR and immunoblotting in hair regrowth model using C57BL/6J mice. KEY RESULTS: In this study, ISX9 was identified as a novel agonist of the Wnt/ß-catenin pathway. ISX9 targeted Axin1 by covalently binding to its N-terminal region and potentiated the LRP6-Axin1 interaction, thereby resulting in the stabilization of ß-catenin and up-regulation of Wnt target genes and stemmness marker genes. Moreover, the topical application of ISX9 markedly promoted hair regrowth in C57BL/6J mice and induced hair follicle transition from telogen to anagen via enhancing Wnt/ß-catenin pathway. CONCLUSIONS AND IMPLICATIONS: Taken together, our study unravelled that ISX9 could activate Wnt/ß-catenin signalling by potentiating the association between LRP6 and Axin1, and may be a promising therapeutic agent for alopecia treatment.

A Therapeutic Whole-Tumor-Cell Vaccine Covalently Conjugated with a TLR7 Agonist.

A single-protein or -peptide vaccine is not sufficient to arouse immune responses in cancer therapy. A whole-tumor-cell vaccine with complete cancer cell antigens and all conformations elicits robust immune responses and is a promising method for the treatment of advanced malignant tumors. In this study, we used 5-azacitidine to stimulate B16-F10 melanoma cells to express toll-like receptor (TLR) 3 on the cell surface and then chemically linked SZU-106, a small-molecule TLR7 agonist, to the cell surface with a pegylated linker to produce a novel whole-tumor-cell vaccine, abbreviated as Aza-BFcell-106. The vaccine stimulated mouse splenic lymphocytes and bone marrow-derived dendritic cells to secrete cytokines, promoted the maturation of dendritic cells and enhanced the capability of dendritic cells to present antigens. In a mouse model of melanoma, the vaccine effectively inhibited tumor growth, decreased tumor volume and prolonged survival. Further combination of the vaccine with a chemokine inhibitor, reparixin, significantly increased the infiltration of CD4+ and CD8+ T cells into the tumor environment, while the antitumor effect was significantly enhanced. The whole-tumor-cell vaccine Aza-BFcell-106 induced immune-activating responses in both in vitro and in vivo experiments, indicating that this vaccine has great potential to treat advanced malignant tumors.

The CK1δ/ϵ-Tip60 Axis Enhances Wnt/ß-Catenin Signaling via Regulating ß-Catenin Acetylation in Colon Cancer.

Casein kinase 1δ/ϵ (CK1δ/ϵ) are well-established positive modulators of the Wnt/ß-catenin signaling pathway. However, the molecular mechanisms involved in the regulation of ß-catenin transcriptional activity by CK1δ/ϵ remain unclear. In this study, we found that CK1δ/ϵ could enhance ß-catenin-mediated transcription through regulating ß-catenin acetylation. CK1δ/ϵ interacted with Tip60 and facilitated the recruitment of Tip60 to ß-catenin complex, resulting in increasing ß-catenin acetylation at K49. Importantly, Tip60 significantly enhanced the SuperTopFlash reporter activity induced by CK1δ/ϵ or/and ß-catenin. Furthermore, a CK1δ/CK1ϵ/ß-catenin/Tip60 complex was detected in colon cancer cells. Simultaneous knockdown of CK1δ and CK1ϵ significantly attenuated the interaction between ß-catenin and Tip60. Notably, inhibition of CK1δ/ϵ or Tip60, with shRNA or small molecular inhibitors downregulated the level of ß-catenin acetylation at K49 in colon cancer cells. Finally, combined treatment with CK1 inhibitor SR3029 and Tip60 inhibitor MG149 had more potent inhibitory effect on ß-catenin acetylation, the transcription of Wnt target genes and the viability and proliferation in colon cancer cells. Taken together, our results revealed that the transcriptional activity of ß-catenin could be modulated by the CK1δ/ϵ-ß-catenin-Tip60 axis, which may be a potential therapeutic target for colon cancer.

BDE-47 induced PC-12 cell differentiation via TrkA downstream pathways and caused the loss of hippocampal neurons in BALB/c mice.

As the most abundant congener of polybrominated diphenyl ethers (PBDEs) detected in environment and human biotic samples, 2, 2', 4, 4'-tetrabromodiphenyl ether (BDE-47) has been found to accumulate in brain and induce neurotoxicity, however, the detailed mechanism has not been clearly elucidated. To investigate the neurotoxicity of BDE-47, undifferentiated PC-12 cells were exposed to different doses of BDE-47, and BDE-47 dissolved in corn oil was orally administered to mice for 8 consecutive weeks. Our data showed that BDE-47 obviously changed cell morphology, altered cell viability, promoted cell apoptosis, and induced reactive oxygen species (ROS) production. BDE-47 promoted the differentiation of PC-12 cells by enhancing the expression of TrkA receptor and the phosphorylation levels of ERK and Akt. Moreover, BDE-47-induced differentiation of PC-12 cells was suppressed by inhibitors of corresponding pathways (MAPK/ERK and PI3K/Akt). H&E staining of brain showed neurons in DG and CA1 areas of hippocampus decreased after BDE-47 exposure. Transcriptome sequencing of brain tissue suggested that multiple signaling pathways related to neuron death and nerve function were significantly regulated. In conclusion, these results provided new evidence for revealing the neurotoxicity of BDE-47, and offered important experimental basis for environmental controlling and post-exposure health risk assessment of BDE-47.

The oral manifestations and related mechanisms of COVID-19 caused by SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19) was reported to be associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, and patients present mostly with respiratory symptoms. There have been an increasing number of reports on oral manifestations, and some of these signs are informative in terms of identifying SARS-CoV-2 infection. The goal of present study was to review and synthesize the clinical characteristics and underlying mechanisms of COVID-19 oral manifestations, as well as to evaluate the factors influencing SARS-CoV-2 infectivity, in order to conduct further in-depth investigations and help clinicians diagnose COVID-19 patients exhibiting oral symptoms.

Transmembrane protein 97 exhibits oncogenic properties via enhancing LRP6-mediated Wnt signaling in breast cancer.

Upregulation of transmembrane protein 97 (TMEM97) has been associated with progression and poor outcome in multiple human cancers, including breast cancer. Recent studies suggest that TMEM97 may be involved in the activation of the Wnt/ß-catenin pathway. However, the molecular mechanism of TMEM97 action on Wnt/ß-catenin signaling is completely unclear. In the current study, TMEM97 was identified as an LRP6-interacting protein. TMEM97 could interact with LRP6 intracellular domain and enhance LRP6-mediated Wnt signaling in a CK1δ/ε-dependent manner. The binding of TMEM97 to LRP6 facilitated the recruitment of CK1δ/ε to LRP6 complex, resulting in LRP6 phosphorylation at Ser 1490 and the stabilization of ß-catenin. In breast cancer cells, knockout of TMEM97 attenuated the Wnt/ß-catenin signaling cascade via regulating LRP6 phosphorylation, leading to a decrease in the expression of Wnt target genes AXIN2, LEF1, and survivin. TMEM97 deficiency also suppressed cell viability, proliferation, colony formation, migration, invasion, and stemness properties in breast cancer cells. Importantly, TMEM97 knockout suppressed tumor growth through downregulating the Wnt/ß-catenin signaling pathway in a breast cancer xenograft model. Taken together, our results revealed that TMEM97 is a positive modulator of canonical Wnt signaling. TMEM97-mediated Wnt signaling is implicated in the tumorigenesis of breast cancer, and its targeted inhibition may be a promising therapeutic strategy for breast cancer.

A Multi-Gene Model Effectively Predicts the Overall Prognosis of Stomach Adenocarcinomas With Large Genetic Heterogeneity Using Somatic Mutation Features.

BACKGROUND: Stomach adenocarcinoma (STAD) is one of the most common malignancies worldwide with poor prognosis. It remains unclear whether the prognosis is associated with somatic gene mutations. METHODS: In this research, we collected two independent STAD cohorts with both genetic profiling and clinical follow-up data, systematically investigated the association between the prognosis and somatic mutations, and analyzed the influence of heterogeneity on the prognosis-genetics association. RESULTS: Typical association was identified between somatic mutations and overall prognosis for individual cohorts. In The Cancer Genome Atlas (TCGA) cohort, a list of 24 genes was also identified that tended to mutate within cases of the poorest prognosis. The association showed apparent heterogeneity between different cohorts, although common signatures could be identified. A machine-learning model was trained with 20 common genes that showed a similar mutation rate difference between prognostic groups in the two cohorts, and it classified the cases in each cohort into two groups with significantly different prognosis. The model outperformed both single-gene models and TNM-based staging system significantly. CONCLUSION: The study made a systematic analysis on the association between STAD prognosis and somatic mutations, identified signature genes that showed mutation preference in different prognostic groups, and developed an effective multi-gene model that can effectively predict the overall prognosis of STAD in different cohorts.

AQP1 suppression by ATF4 triggers trabecular meshwork tissue remodelling in ET-1-induced POAG.

Primary open-angle glaucoma (POAG) is the second leading cause of irreversible blindness worldwide. Increased endothelin-1 (ET-1) has been observed in aqueous humour (AH) of POAG patients, resulting in an increase in the out-flow resistance of the AH. However, the underlining mechanisms remain elusive. Using established in vivo and in vitro POAG models, we demonstrated that water channel Aquaporin 1 (AQP1) is down-regulated in trabecular meshwork (TM) cells upon ET-1 exposure, which causes a series of glaucomatous changes, including actin fibre reorganization, collagen production, extracellular matrix deposition and contractility alteration of TM cells. Ectopic expression of AQP1 can reverse ET-1-induced TM tissue remodelling, which requires the presence of ß-catenin. More importantly, we found that ET-1-induced AQP1 suppression is mediated by ATF4, a transcription factor of the unfolded protein response, which binds to the promoter of AQP1 and negatively regulates AQP1 transcription. Thus, we discovered a novel function of ATF4 in controlling the process of TM remodelling in ET-1-induced POAG through transcription suppression of AQP1. Our findings also detail a novel pathological mechanism and a potential therapeutic target for POAG.

Docetaxel-loaded PAMAM-based poly (γ-benzyl-l-glutamate)-b-d-α-tocopheryl polyethylene glycol 1000 succinate nanoparticles in human breast cancer and human cervical cancer therapy.

Taxane-based chemotherapy-loaded drug delivery systems have great potential for cancer treatment. The docetaxel (DTX)-loaded PAMAM-based poly (γ-benzyl-l-glutamate)-b-d-α-tocopheryl polyethylene glycol 1000 succinate (PAM-PBLG-b-TPGS) nanoparticles and the docetaxel (DTX)-loaded PAMAM-based poly (γ-benzyl-l-glutamate) (PAM-PBLG) nanoparticles were designed using a modified nanoprecipitation method. The particle size, encapsulation efficiency (EE), and in vitro release characteristics of the nanoparticles were tested. The effects of the two nanoparticles on the cellular uptake and cell viability on human cervical cancer cell line Hela and the human breast cancer cell line MCF-7 were compared. Furthermore, their antitumor efficiency was evaluated through in vivo tumour growth experiment in comparison with free DTX. PAM-PBLG-b-TPGS nanoparticles displayed high EE, smaller diameter, and a nice releasing profile. Besides, based on the high EE and 'self-controlled' drug release of the DTX-loaded PAM-PBLG-b-TPGS nanoparticles, they exhibited stronger cytotoxicity (lower survival rate) and higher uptake rate than DTX-loaded PAM-PBLG nanoparticles in Hela cells and MCF-7 cells. Furthermore, compared with DTX-loaded PAM-PBLG nanoparticles and free DTX, DTX-loaded PAM-PBLG-b-TPGS nanoparticles produced a potent anti-tumour effect. Thus, the DTX-loaded PAM-PBLG-b-TPGS nanoparticles provide a novel attractive nanocarrier for the DTX delivery of chemotherapy to human breast cancer cells and human cervical cancer cells.

Metallothionein-1 suppresses rheumatoid arthritis pathogenesis by shifting the Th17/Treg balance.

It is now well accepted that an imbalance between the Th17 and regulatory T-cell responses is closely associated with the development of rheumatoid arthritis (RA). However, the precise regulatory mechanism for the differentiation of Th17 and Treg in RA is not well characterized. The present study showed that metallothionein-1 (MT-1), which is a low molecular weight protein that is involved in the detoxification of heavy metals and scavenging of free radicals, was upregulated in RA. Furthermore, the synovial inflammation and pathologic symptoms in collagen-induced arthritis and collagen antibody-induced arthritis mice were significantly suppressed when MT-1 was expressed intraarticularly. Further investigation revealed that MT-1 inhibited the differentiation of Th17 cells but enhanced that of Treg cells. Furthermore, it markedly decreased both STAT3 and RAR-related orphan receptor gamma t (RORγt) expression in vitro and in vivo. Collectively, our studies demonstrated that MT-1 might manifest as a protein involved in immunosuppression of RA pathogenesis by shifting Th17/Treg balance and may prove to be a potential therapeutic target for RA autoimmune diseases.

Notoginsenoside R7 suppresses cervical cancer via PI3K/PTEN/Akt/mTOR signaling.

Notoginsenoside R7 was isolated from Panax notoginseng, a plant used commonly in traditional Chinese medicine. We investigated the anti-cancer effects of R7 in HeLa cells in vitro and in vivo, and explored the underlying mechanisms of action. R7 dose-dependently inhibited HeLa cell proliferation and induced apoptosis in vitro, In silico docking-based screening assays showed that R7 can directly bind Akt. Pretreatment with the Akt inhibitor LY294002 synergistically enhanced the R7 anti-proliferation and anti-apoptosis effects in HeLa cells, confirming that R7 acts through the PI3K/Akt pathway. Consistent with the in vitro findings, R7 exerted anti-tumor effects in a mouse xenograft model by targeting PI3K (PTEN) and Akt, activating the pro-apoptotic Bcl-2 family and, subsequently, caspase family members. R7 treatment activated PTEN and downregulated mTOR phosphorylation without affecting mTOR expression, though regulatory-associated protein of mTOR (raptor) expression declined. Our study suggests that R7 is a promising chemotherapeutic agent for the treatment of cervical cancer and other PI3K/PTEN/Akt/mTOR signaling-associated tumors.

Local administration of a novel Toll-like receptor 7 agonist in combination with doxorubicin induces durable tumouricidal effects in a murine model of T cell lymphoma.

BACKGROUND: Conventional chemotherapy and radiotherapy for the treatment of lymphoma have notable drawbacks, and passive immunotherapy using a monoclonal antibody is restricted to CD20-positive B cell lymphoma. Therefore, new treatment types are urgently required, especially for T cell lymphoma. One type of new antitumour therapy is the use of active immunotherapeutic agents, such as agonists of the Toll-like receptors (TLRs), which facilitate the induction of prolonged antitumour immune responses. METHODS: We have synthesised a novel TLR7 agonist called SZU-101 and investigated the systemic antitumour effect on a murine model of T cell lymphoma in vivo. RESULTS: Here, we report that the intratumoural administration of SZU-101 enhanced the effectiveness of a conventionally used chemotherapeutic agent, doxorubicin (DOX). SZU-101 administration improved tumour clearance in a murine model of T cell lymphoma. The novel combination of intratumourally administered SZU-101 and DOX generated strong cytokine production and enhanced the cytotoxic T lymphocyte response, leading to the eradication of both local and distant tumours in tumour-bearing mice. CONCLUSIONS: These findings suggested that combined active immunotherapy can be developed as a promising treatment for T cell lymphoma, which may further improve the effectiveness of the current standard cyclophosphamide, DOX, vincristine and prednisone (CHOP) therapy.

Immunomodulatory effects of crude phenylethanoid glycosides from Ligustrum purpurascens.

ETHNOPHARMACOLOGICAL RELEVANCE: Ligustrum purpurascens, named as "Ku ding cha", has been used as a kind of functional tea in southern China for about two thousand years, which has the effects on diuresis, anti-hypertension, weight-loss and anti-inflammation. THE AIM OF THE STUDY: This study was aimed to investigate the immune enhancement effects of the crude phenylethanoid glycosides (CPGs) from Ligustrum. Purpurascens on mice and analyze the chemical profiles of phenylethanoid glycosides in the CPGs. MATERIALS AND METHODS: The immune functions enhancing potential of CPGs was determined using serum hemolysin antibody, phagocytosis, splenocyte antibody production, and NK cells activity assays. The contents of five major constituents in the crude glycosides of Ligustrum purpurascens were determined by using liquid chromatography, other five glycosides were deduced according to their UV and MS spectra compared with the literature as well. RESULTS: In the immunizing experiment, mice treated with different doses of CPGs showed an increase (p<0.01) in the haemagglutination titre compared with the control group. The increases (p<0.05) were found to be significant at doses of 440 mg/kg and 1.32 g/kg in the experiments of antibody production of spleen cells, MΦ phagocytosis of chicken RBCs and NK cell activity. Further chemical characterization yielded 10 constituents from CPGs, five glycosides were quantified by HPLC and the structures of other five compounds were speculated according to their UV and MS spectra. CONCLUSION: The results suggested that phenylethanoid glycosides from Ligustrum purpurascens have immunomodulatory effects on mice.