Neuroprotection Role of Vitamin C by Upregulating Glutamate Transporter-1 in Auditory Cortex of Noise-Induced Tinnitus Animal Model.

Vitamin C (Vc) plays a pivotal role in a series of pathological processes, such as tumors, immune diseases, and neurological disorders. However, its therapeutic potential for tinnitus management remains unclear. In this study, we find that Vc relieves tinnitus in noise-exposed rats. In the 7-day therapy groups, spontaneous firing rate (SFR) increases from 1.17 ± 0.10 Hz to 1.77 ± 0.15 Hz after noise exposure. Vc effectively reduces the elevated SFR to 0.99 ± 0.07 and 0.55 ± 0.05 Hz at different doses. The glutamate level in auditory cortex of noise-exposed rats (3.78 ± 0.42 µM) increases relative to that in the control group (1.34 ± 0.22 µM). High doses of Vc (500 mg/kg/day) effectively reduce the elevated glutamate levels (1.49 ± 0.28 µM). Mechanistic studies show that the expression of glutamate transporter 1 (GLT-1) is impaired following noise exposure and that Vc treatment effectively restores GLT-1 expression in the auditory cortex. Meanwhile, the GLT-1 inhibitor, dl-threo-beta-benzyloxyaspartic acid (dl-TBOA), invalidates the protection role of Vc. Our finding shows that Vc substantially enhances glutamate clearance by upregulating GLT-1 and consequently alleviates noise-induced tinnitus. This study provides valuable insight into a novel biological target for the development of therapeutic interventions that may prevent the onset of tinnitus.

Progress of studies on natural products for glioblastoma therapy.

Glioblastoma (GBM) is the most common, malignant, and lethal primary brain tumor in adults. Up to now, the chemotherapy approaches for GBM are limited. Therefore, more studies on identifying and exploring new chemotherapy drugs or strategies overcome the GBM are essential. Natural products are an important source of drugs against various human diseases including cancers. With the better understanding of the molecular etiology of GBM, the development of new anti-GBM drugs has been increasing. Here, we summarized recent researches of natural products for the GBM therapy and their potential mechanisms in details, which will provide new ideas for the research on natural products and promote developing drugs from nature products for GBM therapy.

MSC-derived exosomes protect auditory hair cells from neomycin-induced damage via autophagy regulation.

BACKGROUND: Sensorineural hearing loss (SNHL) poses a major threat to both physical and mental health; however, there is still a lack of effective drugs to treat the disease. Recently, novel biological therapies, such as mesenchymal stem cells (MSCs) and their products, namely, exosomes, are showing promising therapeutic potential due to their low immunogenicity, few ethical concerns, and easy accessibility. Nevertheless, the precise mechanisms underlying the therapeutic effects of MSC-derived exosomes remain unclear. RESULTS: Exosomes derived from MSCs reduced hearing and hair cell loss caused by neomycin-induced damage in models in vivo and in vitro. In addition, MSC-derived exosomes modulated autophagy in hair cells to exert a protective effect. Mechanistically, exogenously administered exosomes were internalized by hair cells and subsequently upregulated endocytic gene expression and endosome formation, ultimately leading to autophagy activation. This increased autophagic activity promoted cell survival, decreased the mitochondrial oxidative stress level and the apoptosis rate in hair cells, and ameliorated neomycin-induced ototoxicity. CONCLUSIONS: In summary, our findings reveal the otoprotective capacity of exogenous exosome-mediated autophagy activation in hair cells in an endocytosis-dependent manner, suggesting possibilities for deafness treatment.

Actinomycin D synergizes with Doxorubicin in triple-negative breast cancer by inducing P53-dependent cell apoptosis.

OBJECTIVES: There are three major subtypes of breast cancer, ER+, HER2+ and triple-negative breast cancer (TNBC), namely ER-, PR-, HER2-. TNBC is the most aggressive breast cancer with poor prognosis and no target drug up to now. Actinomycin D (ActD) is a bioactive metabolite of marine bacteria that has been reported to have antitumor activity. The aim of study is to investigate whether ActD has a synergetic effect on TNBC with Doxorubicin (Dox), the major chemotherapeutic drug for TNBC, and explore the underlying mechanism. METHODS: TNBC cell lines HCC1937, MDA-MB-436 and nude mice were used in the study. Drug synergy determination, LDH assay, MMP assay, Hoechst 33342 staining, Flow cytometry, Flexible docking and CESTA assay were carried out. The expression of proteins associated with apoptosis was checked by Western blot and siRNA experiments were performed to investigate the role of P53 and PUMA induced by drugs. RESULTS: There was much higher apoptosis rate of cells in the ActD + Dox group than that in ActD group or Dox group. Expression of MDM2 and BCL-2 was reduced while expression of P53, PUMA and BAX were increased in the groups treated with ActD + Dox or Dox compared to the control group. Furthermore, P53 siRNA or PUMA siRNA tremendously abrogated the cell apoptosis in the groups treated by ActD, Dox and ActD + Dox. Flexible docking and CESTA showed that ActD can bind MDM2. CONCLUSIONS: ActD had a synergetic effect on TNBC with Dox via P53-dependent apoptosis and it may be a new choice for treatment of TNBC.

Research progress on the regulatory mechanisms of FOXC1 expression in cancers and its role in drug resistance.

The Forkhead box C1 (FOXC1) transcription factor is an important member of the FOX family. After initially being identified in triple-negative breast cancer (TNBC) with significant oncogenic function, FOXC1 was subsequently demonstrated to be involved in the development of more than 16 types of cancers. In recent years, increasing studies have focused on the deregulatory mechanisms of FOXC1 expression and revealed that FOXC1 expression was regulated at multiple levels including transcriptional regulation, post-transcription regulation and post-translational modification. Moreover, dysregulation of FOXC1 is also implicated in drug resistance in various types of cancer, especially in breast cancer, which further emphasizes the translational and clinical significance of FOXC1 as a therapeutic target in cancer treatment. This review summarizes recent findings on mechanisms of FOXC1 dysregulation in cancers and its role in chemoresistance, which will help to better understand the oncogenic role of FOXC1, overcome FOXC1-mediated drug resistance and develop targeted therapy for FOXC1 in cancers.

MSC-derived exosomes protect auditory hair cells from neomycin-induced damage via autophagy regulation

BACKGROUND: Sensorineural hearing loss (SNHL) poses a major threat to both physical and mental health; however, there is still a lack of effective drugs to treat the disease. Recently, novel biological therapies, such as mesenchymal stem cells (MSCs) and their products, namely, exosomes, are showing promising therapeutic potential due to their low immunogenicity, few ethical concerns, and easy accessibility. Nevertheless, the precise mechanisms underlying the therapeutic effects of MSC-derived exosomes remain unclear. RESULTS: Exosomes derived from MSCs reduced hearing and hair cell loss caused by neomycin-induced damage in models in vivo and in vitro. In addition, MSC-derived exosomes modulated autophagy in hair cells to exert a protective effect. Mechanistically, exogenously administered exosomes were internalized by hair cells and subsequently upregulated endocytic gene expression and endosome formation, ultimately leading to autophagy activation. This increased autophagic activity promoted cell survival, decreased the mitochondrial oxidative stress level and the apoptosis rate in hair cells, and ameliorated neomycin-induced ototoxicity. CONCLUSIONS: In summary, our findings reveal the otoprotective capacity of exogenous exosome-mediated autophagy activation in hair cells in an endocytosis-dependent manner, suggesting possibilities for deafness treatment.

Loss of SENP3 mediated the formation of nasal polyps in nasal mucosal inflammation by increasing alternative activated macrophage.

BACKGROUND AND AIM: Small ubiquitin-like modifier (SUMO)-specific protease (SENP)3 is a protease molecule that responds to reactive oxygen species (ROS) with high sensitivity. However, the role of ROS and SENP3 in the formation of nasal polyps (NPs) remains unclear. This study aimed to explore how SENP3 influenced the outcome of chronic rhinosinusitis (CRS) by altering macrophage function, that is, the formation of NPs. METHODS: The alternative activation of macrophage (M2) was detected with CD68+ CD206+ in humans and CD206+ in mice. The nasal mucosa of patients with CRS was tested using flow cytometry (CD68, CD80, and CD206) and triple-color immunofluorescence staining (CD68, CD206, and SENP3). The bone marrow-derived macrophages from SENP3 knockout and control mice were stimulated with interleukin (IL)-4 and IL-13 to analyze alternative macrophage polarization in vitro. An animal model of allergic rhinitis was constructed using SENP3 knockout mice. CD206 was detected by immunofluorescence staining. The thickening of eosinophil-infiltrated mucosa was detected by Luna staining. RESULTS: The number of CD68+ CD206+ M2 increased in the nasal mucosa of patients with CRS with NP (CRSwNP) compared with patients with CRS without NP (CRSsNP), but with no significant difference between the groups. SENP3 knockout increased the polarization of F4/80+ CD206+ M2. Meanwhile, the number of CD206+ M2 significantly increased in the allergic rhinitis model constructed using SENP3 knockout mice and controls, with a more obvious proliferation of the nasal mucosa. CONCLUSION: Downregulation of SENP3 promotes the formation of nasal polyps mediated by increasing alternative activated macrophage in nasal mucosal inflammation.

Water-Soluble Photoluminescent Adenosine-Functionalized Gold Nanoclusters as Highly Sensitive and Selective Receptors for Riboflavin Detection in Rat Brain.

Simple, selective, and sensitive detection of cerebral riboflavin is of great significance due to the vital roles of riboflavin in physiological and pathological processes. In the work, water-soluble photoluminescent adenosine-functionalized gold nanoclusters (Ade-AuNCs) are exploited as highly sensitive and selective receptors for cerebral riboflavin detection. The Ade-AuNCs are prepared under aqueous conditions by the one-step "synthesis-functionalization integration" strategy, using chloroauric acid as gold precursors and adenosine as outer-shell ligands. During the Ade-AuNCs synthesis process, adenosine and ascorbic acid are demonstrated to respectively serve as a stabilizer and a reductant, and citrate buffer plays multiple roles including a pH regulator, reductant, and complexing agent. The added riboflavin causes photoluminescence quenching of Ade-AuNCs, and the quenching photoluminescence is applied for well quantifying riboflavin in the range of 0.005-0.1 nM with a detection limit of 0.002 nM. The detailed analytical characterizations reveal that the photoluminescence quenching results from the static photoinduced electron transfer process from the surface functional Ade-AuNCs to riboflavin and the strong affinity between Ade-AuNCs and riboflavin. Moreover, the Ade-AuNC-based sensor exhibits a high selectivity for riboflavin over metal ions, anions, amino acids, and biological substances that possibly exist in the rat brain. Finally, by coupling the microdialysis technique, the proposed sensor is successfully applied to detect riboflavin in living rat brain microdialysates with a basal value of 13.1 ± 2.5 nM (n = 3), and the results are comparable well with those from a reference high-performance liquid chromatography method.

[Expression and predictive value of type â ¡ inflammatory cytokines in nasal secretion in eosinophilic chronic rhinosinusitis with nasal polyps].

Objective:To analyze the expression of type Ⅱ inflammatory-related cytokines in nasal secretions of patients with eosinophilic chronic rhinosinusitis with nasal polyps（ECRSwNP）, and to preliminarily explore the role of type Ⅱ inflammatory cytokines in nasal secretions in predicting ECRSwNP. Methods:A prospective analysis was made of 91 patients with CRSwNP who underwent endoscopic sinus surgery in Peking University Third Hospital from November 2020 to June 2021. All the selected patients had their SNOT-22 score, Lund-Mackay score and blood eosinophilia collected before surgery. Percentage and absolute value; the nasal secretions of patients were collected before operation, and enzyme-linked immunosorbent assay was used to detect the typeⅡinflammatory cytokines（IL-4, IL-5, IL-13, IL-25, IL-33, Eotaxin-3, periostin）, intraoperative nasal polyp tissue was collected for eosinophil count. According to the proportion of eosinophils in the tissue≥10%, they were divided into ECRSwNP group and nECRSwNP group. The clinical baseline data and type Ⅱ inflammatory cytokines were compared between the two groups, and the related factors of ECRSwNP were evaluated by univariate logistic regression analysis. The receiver operating characteristic（ROC） curve was used to evaluate the predictive potential of each clinical index. Results:The SNOT-22 score, Lund-Mackay score, blood eosinophil percentage and absolute value in the ECRSwNP group were higher than those in the nECRSwNP group（P<0.05）. In the nECRSwNP group（P<0.01）. Logistic regression analysis found that IL-5, Eotaxin-3 and blood eosinophil percentage were risk factors for ECRSwNP（P<0.05）. ROC analysis found that IL-5, Eotaxin-3 and blood eosinophil percentage had predictive diagnostic value（P<0.01）, among which blood eosinophil percentage had the greatest predictive value（AUC=0.756）. The prediction model composed of Eotaxin-3, SNOT-22 score, sinus CT Lund-Mackay score, blood eosinophil percentage and blood eosinophil absolute value had better prediction effect on ECRSwNP（AUC=0.873）. Conclusion:Type Ⅱ inflammatory cytokines IL-5 and Eotaxin-3 in nasal secretions may be involved as biomarkers for early diagnosis of ECRSwNP.

Tissue eosinophils and mucous inflammatory cytokines for the evaluation of olfactory recovery after endoscopic sinus surgery in patients with nasal polyposis.

The etiologies of chronic rhinosinusitis with nasal polyps (CRSwNP)-associated olfactory dysfunction have several potentially overlapping hypotheses. Understanding the association of tissue eosinophils and mucous inflammatory cytokines with olfactory function and identifying predictors of olfactory outcomes in patients with nasal polyposis after surgery is fundamental for future clinical care and research. METHODS: Eighty-five patients who underwent endoscopic surgery for nasal polyposis were enrolled in this study. Olfactory measurements were performed before surgery and 3-6 months after surgery using a T&T olfactometer. Baseline characteristics of CRSwNP patients were collected, and Spearman's rho correlation was performed to assess the association of olfactory function with tissue eosinophils and mucous inflammatory cytokines. A multivariate logistic regression model was used to assess the independent predictors of olfactory outcomes after surgery. RESULTS: Here, 85 CRSwNP patients, including 25 patients without olfactory disorder and 60 patients with hypo-anosmia, were evaluated. Of the 60 patients with preoperative hypo-anosmia, 22 did not have improved olfactory function, and 38 demonstrated normal olfactory function after surgery based on the T&T olfactometer results. The levels of tissue eosinophil, interleukin-5 (IL-5), IL-13, eotaxin-3, and periostin in the preoperative hypo-anosmia group were higher than those in the preoperative normosmia group. Tissue eosinophil count, IL-5, and periostin levels in patients without olfactory improvement were higher than those in patients with olfactory improvement. The tissue eosinophil count, blood eosinophil count, and nasal mucus levels of IL-5, eotaxin-3, and periostin were significantly correlated with olfactory function in all patients with CRSwNP. The IL-5 level remained a strong predictor of poor olfactory outcomes after surgery. CONCLUSIONS: Both tissue eosinophils and mucous inflammatory cytokines, including IL-5, IL-13, eotaxin-3, and periostin, may contribute to the pathogenesis of CRSwNP-associated olfactory dysfunction. Higher IL-5 levels are associated with a lower chance of olfactory function recovery after each surgical revision.

Sinus Microbiota in Patients With Eosinophilic and Non-Eosinophilic Chronic Rhinosinusitis With Nasal Polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by Th2-skewed inflammation and increased colonization by Staphylococcus aureus. CRSwNP can be distinguished as eosinophilic (ECRSwNP) and non-eosinophilic (NECRSwNP) by the infiltration of eosinophils. The local microbiota plays an important role in the persistent inflammation of CRSwNP. To evaluate the bacterial community composition on the distinct types of CRSwNP patients, we collected nasal swabs from 16 ECRSwNP patients, 18 NECRSwNP patients, and 39 healthy control subjects. The microbiome structure for all the samples were analyzed by high-throughput 16S rRNA gene sequencing. Concentration of S. aureus was determined using TaqMan quantitative polymerase chain reaction (qPCR) targeting the nuclease (nuc) gene. The result showed significant differences in the sinus microbiome among healthy control subjects and CRSwNP patients. Microbiota community diversity was significantly lower in NECRSwNP samples compared to that of healthy control subjects. Interestingly, the abundance of several pathogenic bacteria was diverse between ECRSwNP and NECRSwNP patients. Although Staphylococcus prevailed in all groups, the abundance of Staphylococcus was significantly higher in the healthy control group than the ECRSwNP group. More importantly, the abundance of S. aureus was much higher in NECRSwNP patients. This study highlights that microbiota composition may contribute to the different clinical types of CRSwNP, inspiring new therapeutic strategies to resolve this chronic inflammation process.

Post-Surgery Subcutaneous Seeding of Laryngeal Squamous Cell Carcinoma: A Rare Case.

Laryngeal squamous cell carcinoma (LSCC) is the most common malignant head and neck cancer, with a 40% recurrence rate in the first 3 years after radical treatment. Recurrence of LSCC mostly comprises lymphogenous metastasis, hematogenic metastasis, and locoregional recurrence, while LSCC seeding is rarest: there are only 4 cases reported in PubMed, and none of them is one of subcutaneous seeding. We report a case with post-surgery subcutaneous seeding of LSCC. The final biopsy demonstrated that the subcutaneous seeding of the LSCC was 2 cm away from the primary lesion, with no recurrent foci observed in the larynx and tracheostoma and little relation to the primary lesion. Thus, we drew the conclusion that LSCC surgeries should stick to the principle of the non-tumor technique to prevent subcutaneous seeding.

Peripheral blood eosinophil levels in chronic rhinosinusitis and its predictive value in eosinophilic chronic rhinosinusitis.

BACKGROUND: The prevalence of eosinophilic CRSwNP in China has increased significantly over the last 20 years, noninvasive methods that could assist in diagnosis are urgently needed. AIMS: The aim of this study is to explore the clinical significance of peripheral blood eosinophil in diagnosing ECRS. MATERIALS AND METHODS: We conducted a prospective study of 221 patients diagnosed with CRS. Lund-Mackay score, peripheral blood eosinophil absolute count, peripheral blood eosinophil percentage were detection to compare the clinical features with ECRS and non-ECRS. ROC curve was performed to assess the efficiency of clinical index to predict ECRS. RESULTS: The ECRS group of patients had significantly higher scores compared with those of the non-ECRS group. Different extent and severity of mucosal thickening on total Lund-Mackay scores, anterior ethmoidal, posterior ethmoidal and ostiomeatal complex have confirmed different blood eosinophil levels in CRS patients. The combination of peripheral blood eosinophil percentage and posterior ethmoidal score to predict ECRS was 0.807. CONCLUSIONS AND SIGNIFICANCE: The increase in peripheral blood eosinophil percent indicates the deterioration the inflammation of chronic rhinosinusitis and the level of posterior ethmoidal score and peripheral blood eosinophil percentage have a positive predictive value regarding ECRS identification.

Lysosomal exocytosis of ATP is coupled to P2Y2 receptor in marginal cells in the stria vascular in neonatal rats.

Adenosine triphosphate (ATP) is stored as lysosomal vesicles in marginal cells of the stria vascular in neonatal rats, but the mechanisms of ATP release are unclear. Primary cultures of marginal cells from 1-day-old Sprague-Dawley rats were established. P2Y2 receptor and inositol 1,4,5-trisphosphate (IP3) receptor were immunolabelled in marginal cells of the stria vascular. We found that 30 µM ATP and 30 µM uridine triphosphate (UTP) evoked comparable significant increases in the intracellular Ca2+ concentration ([Ca2+]i) in the absence of extracellular Ca2+, whereas the response was suppressed by 100 µM suramin, 10 µM 1-(6-(17ß-3-methoxyester-1,3,5(10)-trien-17-yl)amino)-hexyl)-1H-pyrrole-2,5-dione(U-73122), 100 µM 2-aminoethoxydiphenyl borate (2-APB) and 5 µM thapsigargin (TG), thus indicating that ATP coupled with the P2Y2R-PLC-IP3 pathway to evoke Ca2+ release from the endoplasmic reticulum (ER). Incubation with 200 µM Gly-Phe-ß-naphthylamide (GPN) selectively disrupted lysosomes and caused significant increases in [Ca2+]I; this effect was partly inhibited by P2Y2R-PLC-IP3 pathway antagonists. After pre-treatment with 5 µM TG, [Ca2+]i was significantly lower than that after treatment with P2Y2R-PLC-IP3 pathway antagonists under the same conditions, thus indicating that lysosomal Ca2+ triggers Ca2+ release from ER Ca2+ stores. Baseline [Ca2+]i declined after treatment with the Ca2+ chelator 50 µM bis-(aminophenolxy) ethane-N,N,N',N'-tetra-acetic acid acetoxyme-thyl ester (BAPTA-AM) and 4 IU/ml apyrase. 30 µM ATP decrease of the number of quinacrine-positive vesicles via lysosome exocytosis, whereas the number of lysosomes did not change. However, lysosome exocytosis was significantly suppressed by pre-treatment with 5 µM vacuolin-1. Release of ATP and ß-hexosaminidase both increased after treatment with 200 µM GPN and 5 µM TG, but decreased after incubation with 50 µM BAPTA-AM, 4 IU/ml apyrase and 5 µM vacuolin-1. We suggest that ATP triggers Ca2+ release from the ER, thereby contributing to secretion of lysosomal ATP via lysosomal exocytosis. Lysosomal stored Ca2+ triggers Ca2+ release from the ER directly though the IP3 receptors, and lysosomal ATP evokes Ca2+ signals indirectly via the P2Y2R-PLC-IP3 pathway.