Low-Molecular-Weight Hyaluronic Acid Contributes to Noise-Induced Cochlear Inflammation.

INTRODUCTION: Our previous work indicated that the activation of the Toll-like receptor (TLR) 4 signaling pathway contributed to noise-induced cochlear inflammation. Previous studies have reported that low-molecular-weight hyaluronic acid (LMW-HA) accumulates during aseptic trauma and promotes inflammation by activating the TLR4 signaling pathway. We hypothesized that LMW-HA or enzymes synthesizing or degrading HA might be involved in noise-induced cochlear inflammation. METHODS: The present study included two arms. The first arm was the noise exposure study, in which TLR4, proinflammatory cytokines, HA, hyaluronic acid synthases (HASs), and hyaluronidases (HYALs) in the cochlea as well as auditory brainstem response (ABR) thresholds were measured before and after noise exposure. The second arm was analysis of HA delivery-induced reactions, in which control solution, high-molecular-weight HA (HMW-HA), or LMW-HA was delivered into the cochlea by cochleostomy or intratympanic injection. Then, the ABR threshold and cochlear inflammation were measured. RESULTS: After noise exposure, the expression of TLR4, proinflammatory cytokines, HAS1, and HAS3 in the cochlea significantly increased over the 3rd to 7th day post-noise exposure (PE3, PE7). The expression of HYAL2 and HYAL3 dramatically decreased immediately after noise exposure, gradually increased thereafter to levels significantly greater than the preexposure level on PE3, and then rapidly returned to the preexposure level on PE7. The expression of HA, HAS2, and HYAL1 in the cochlea remained unchanged after exposure. After cochleostomy or intratympanic injection, both the hearing threshold shifts and the expression of TLR4, TNF-α, and IL-1ß in the cochleae of the LMW-HA group were obviously greater than those of the control group and HMW-HA group. The expression of proinflammatory cytokines in the LMW-HA and control groups on the 7th day (D7) after cochleostomy tended to increase compared to that on the 3rd day (D3), whereas levels in the HMW-HA group tended to decrease on D7 compared to D3. CONCLUSION: HAS1, HAS3, HYAL2, and HYAL3 in the cochlea are involved in acoustic trauma-induced cochlear inflammation through the potential proinflammatory function of LMW-HA.

Molecular networking as a dereplication strategy for monitoring metabolites of natural product treated cancer cells.

RATIONALE: Natural products have been great sources for drug discovery. However, the structures of natural products are diverse and difficult to elucidate. Cordyceps militaris is a parasitic fungus which usually grows on host insects. The metabolites of C. militaris have been reported to act as chemotherapeutic agents. In this study, we aimed for the structural elucidation of specialized metabolites derived from C. militaris, and the metabolic impact in leukemia cells. METHODS: We describe a liquid chromatography data-dependent mass spectrometric platform combining tandem mass analysis and molecular networking. Leukemia cells treated with C. militaris extract and control groups were visualized in terms of their metabolic profiles using Global Natural Product Social (GNPS) molecular networking. By this method, we were able to elucidate the structures of metabolites from medicinal fungus extracts and cancer cells and then to recognize their changes in a semi-quantitative manner. RESULTS: Using C. militaris and leukemia cells as examples, we found that approximately 100 new ion species were present in the treated leukemia cells, suggesting a highly altered metabolic profile. Specifically, based on the tandem mass spectral similarity, we proposed that cordycepin, a key fungus-derived therapeutic agent known for its antitumor activity, was transformed into its methylthio form in leukemia cells. CONCLUSIONS: The platform described provides an ability to investigate complex molecular interactions of natural products in mammalian cells. By incorporating tandem mass spectrometry and molecular networking, we were able to reveal the chemical modification of crude bioactive compounds, for example potential bioactive compounds which might be modified from cordycepin. We envision that such a mass spectrometry (MS)-based workflow, combined with other metabolomics platforms, would enable much wider applicability to cell biology and be of great potential to pharmacological study as well as drug discovery.

A brief review of monoclonal antibody technology and its representative applications in immunoassays.

Modern immunoassay methods and techniques are important tools in labs of basic biology, biomedicine, clinical medicine, and even in home tests, such as pregnant test, many of which utilize antibody-antigen binding mechanism as their foundational principle in common. Meanwhile, compared with polyclonal anitbody, monoclonal antibody shows obvious advantages in their application of modern immunoassays. Furthermore, the progress of other technologies have also promoted the development of modern immunoassays robustly, and widely made it extend into more research and industry fields. In this review, we will first look back to the discovery of antibody-antigen binding mechanism, antibody structure, and the development of monoclonal antibody technology. Then, a brief description of different classical immunoassays will be introduced, such as enzyme-linked immunosorbent assay, flow cytometry, Immunoprecipitation, and lateral flow immunoassays, through of which, we hope a brief and clear picture can be displayed in front of readers. ABBREVIATIONS: ELISA: Enzyme-Linked Immunosorbent Assay; WB: western blot; Mab: monoclonal antibody; IP: immunoprecipitation; LFIAs: lateral flow immunoassays.

[Analysis on the relationship between tensor veli palatini and secretory otitis media in patients with nasopharyngeal carcinoma after radiotherapy].

OBJECTIVE: The analyze the relationship between secretory otitis media (SOM) and injury of tensor veli palatini (TVP) muscle injury after radiotherapy, then to explore the pathogenesis of SOM in patients with nasopharyngeal carcinoma (NPC) after radiotherapy. METHOD: The cross section area (CSA) of TVP and medial pterygoid (MP) muscle were measured in MRI of 32 patients with NPC before and after radiotherapy, meanwhile the incidence of SOM were surveyed after radiotherapy, then to analyze the relationship between the change of TVP and the incidence of SOM after radiotherapy. RESULT: Of 48 ears without SOM before radiotherapy, 27 ears developed post-irradiation SOM, including 24 ears with TVP atrophy and 3 ears without TVP atrophy, and 21 ears had no post-irradiation SOM, including 8 ears with TVP atrophy and 13 ears without TVP atrophy. chi2 test showed significant difference (P < 0.01). It indicated that post-irradiation SOM have correlation with TVP atrophy. The more possibility of TVP atrophy occurred after long time radiotherapy. CONCLUSION: The atrophy of TVP in patients with NPC usually occurs 6 months after radiotherapy, and this may result in the post-irradiation SOM. The pathogenesis of post-irradiation SOM need further study functionally.