Lysophosphatidic acid exerts protective effects on HEI-OC1 cells against cytotoxicity of cisplatin by decreasing apoptosis, excessive autophagy, and accumulation of ROS.

Lysophosphatidic acid (LPA) is an active phospholipid signaling molecule that binds to six specific G protein-coupled receptors (LPA1-6) on the cell surface and exerts a variety of biological functions, including cell migration and proliferation, morphological changes, and anti-apoptosis. The earliest study from our group demonstrated that LPA treatment could restore cochlear F-actin depolymerization induced by noise exposure, reduce hair cell death, and thus protect hearing. However, whether LPA could protect against cisplatin-induced ototoxicity and which receptors play the major role remain unclear. To this end, we integrated the HEI-OC1 mouse cochlear hair cell line and zebrafish model, and found that cisplatin exposure induced a large amount of reactive oxygen species accumulation in HEI-OC1 cells, accompanied by mitochondrial damage, leading to apoptosis and autophagy. LPA treatment significantly attenuated autophagy and apoptosis in HEI-OC1 cells after cisplatin exposure. Further investigation revealed that all LPA receptors except LPA3 were expressed in HEI-OC1 cells, and the mRNA expression level of LPA1 receptor was significantly higher than that of other receptors. When LPA1 receptor was silenced, the protective effect of LPA was reduced and the proportion of apoptosis cells was increased, indicating that LPA-LPA1 plays an important role in protecting HEI-OC1 cells from cisplatin-induced apoptosis. In addition, the behavioral trajectory and in vivo fluorescence imaging results showed that cisplatin exposure caused zebrafish to move more actively, and the movement speed and distance were higher than those of the control and LPA groups, while LPA treatment reduced the movement behavior. Cisplatin caused hair cell death and loss in zebrafish lateral line, and LPA treatment significantly protected against hair cell death and loss. LPA has a protective effect on hair cells in vitro and in vivo against the cytotoxicity of cisplatin, and its mechanism may be related to reducing apoptosis, excessive autophagy and ROS accumulation.

Cuproptosis-related LINC02454 as a biomarker for laryngeal squamous cell carcinoma based on a novel risk model and in vitro and in vivo analyses.

PURPOSE: Laryngeal squamous cell carcinomas (LSCCs) are aggressive tumors with the second-highest morbidity rate in patients with head and neck squamous cell carcinoma. Cuproptosis is a type of programmed cell death that impacts tumor malignancy and progression. The purpose of this study was to investigate the relationship between cuproptosis-related long non-coding RNAs (crlncRNAs) and the tumor immune microenvironment and chemotherapeutic drug sensitivity in LSCC, and crlncRNA impact on LSCC malignancy. MATERIALS AND METHODS: Clinical and RNA-sequencing data from patients with LSCC were retrieved from the Cancer Genome Atlas. Differentially expressed prognosis-related crlncRNAs were identified based on univariate Cox regression analysis, a crlncRNA signature for LSCC was developed and validated using LASSO Cox regression. Finally, the effect of LINC02454, the core signature crlncRNA, on LSCC malignancy progression was evaluated in vitro and in vivo. RESULTS: We identified a four-crlncRNA signature (LINC02454, AC026310.1, AC090517.2, and AC000123.1), according to which we divided the patients into high- and low-risk groups. The crlncRNA signature risk score was an independent prognostic indicator for overall and progression-free survival, and displayed high predictive accuracy. Patients with a higher abundance of infiltrating dendritic cells, M0 macrophages, and neutrophils had worse prognoses and those in the high-risk group were highly sensitive to multiple chemotherapeutic drugs. Knockdown of LINC02454 caused tumor suppression, via cuproptosis induction. CONCLUSIONS: A novel signature of four crlncRNAs was found to be highly accurate as a risk prediction model for patients with LSCC and to have potential for improving the diagnosis, prognosis, and treatment of LSCC.

N-acetylcysteine protect inner hair cells from cisplatin by alleviated celluar oxidative stress and apoptosis.

Cisplatin is a well-known platinum-based chemotherapy drug widely used to treat a variety of malignant tumors. However, cisplatin has serious side-effects include nephrotoxicity and ototoxicity, Cisplatin chemotherapy causes permanent hearing loss at least 40% of treated patients. Our results showed that 20 mM N-acetylcysteine (NAC) can completely protect 50 µM cisplatin-induced hair cell loss in rat cochlear culture and protects against cisplatin-induced hair cell loss in zebrafish in vivo. The fluorescence intensity of mitochondrial ROS significantly increased after the cultures were treated with 15 µM cisplatin for 48 h and was decreased in the group treated with 15 µM cisplatin add 20 mM NAC. In addition, the number of TUNEL positive hair cells was increased after the cultures were treated with 15 µM cisplatin for 48 h and there are null in cisplatin and NAC co-treated group.

A forskolin-loaded nanodelivery system prevents noise-induced hearing loss.

Hearing loss is the most common sensory disorder worldwide and may result from age, drugs, or exposure to excessive noise. Crossing the blood-labyrinth barrier to achieve targeted drug delivery to the inner ear is key to the treatment of hearing loss. We designed a nanoparticle (NP)-based system for targeted drug delivery of forskolin (FSK) to the inner ear, driven by the prestin-targeting peptide LS19 ("ligand-receptor type interaction"). In vivo experiments in developing zebrafish embryos (4-96 h past fertilization) and mice confirmed that LS19-FSK specifically targeted and accumulated in zebrafish lateral line neuromasts and mouse outer hair cells (OHCs). LS19 peptide modification enabled LS19-FSK-NPs to rapidly target OHCs with high specificity. Furthermore, the multifunctional LS19-FSK-NPs were successfully delivered to the OHCs via the round window membrane route and exhibited slow-release properties. The sustained release and intracellular accumulation of FSK inhibited apoptosis of OHCs. Compared with LS19-NPs and FSK-NPs, LS19-FSK-NPs provided significantly stronger protection against noise-induced hearing damage, based on auditory brainstem responses at 4, 8, 16, and 32 kHz. Thus, our specially designed targeted nano-delivery system may serve as a basis for future clinical applications and treatment platforms and has the potential to significantly improve the treatment results of many inner ear diseases.

Immune safety evaluation of polymerized porcine hemoglobin (pPolyHb): a potential red blood cell substitute.

Polymerized Porcine Hemoglobin (pPolyHb), a hemoglobin-based oxygen carrier (HBOC), was developed as a potential red blood substitute for clinical applications. Assessment of its effects on the immune system is an important component of the overall safety evaluation of HBOC. For this purpose, we assessed three inflammation indicators, including complement C3a, IL-6, and TNF-? in cultured cells and in a rat model when pPolyHb was incubated or administrated with the cells/animals. Our results suggested that the levels of these three indicators were not statistically changed upon pPolyHb stimulation, indicating that pPolyHb is not immunotoxic to cells and animals in this aspect.

Enzymic synthesis of gastrodin through microbial transformation and purification of gastrodin biosynthesis enzyme.

Gastrodin, a major bioactive component of a famous Chinese herb Gastrodia elata B1., has diverse pharmaceutical functions. It is usually obtained by extraction from a plant or through chemical synthesis. However, traditional extraction from Gastrodia elata B1. is time and money consuming, while chemical synthesis is a complicated procedure and always leads to very serious environmental pollution. Thus it is urgent to explore a new gastrodin source which is more economical and environmental. The present study reports a novel approach to the production of gastrodin through biosynthesis and microbial transformation. Rhizopus chinensis SAITO AS3.1165 was screened from about 50 fungal and bacterial strains and found capable of biotransforming p-hydroxybenzaldehyde into gastrodin for use in gastrodin production. A series of purification steps including (NH(4))(2)SO(4) precipitation, ion exchange chromatography and gel filtration column chromatography was successfully used for purification of the gastrodin biosynthesis enzyme (GBE). The purity of GBE was above 95% and its molecular weight was about 63.2 kDa. We further characterized GBE's function condition, and found that the optimal temperature was 50 °C and the optimum pH 6.0. The enzyme was stable at a temperature lower than 50 °C and a pH between 6.0 and 9.0. The result indicated that gastrodin could be successfully synthesized by microbial transformation, providing a new approach for gastrodin production.

Outer hair cells isolation from postnatal Sprague-Dawley rats.

Outer hair cells (OHCs) damage is a general phenomenon in clinical disorders such as noise-induced hearing loss and drug-induced hearing loss. In order to elucidate the mechanism underlying these disorders, OHCs - its diseased region needs to be deeply investigated. However, OHCs array on the basilar membrane which contains massive cells with different types. Therefore, to isolate OHCs from this huge population is significant for revealing its pathological and molecular changes during disease processing. In the present study, we tried to isolate OHCs from the commonly used animal model -Sprague-Dawley (SD) rats. By separating outer hair cells from SD rats with different day ages, we found that 9 days after birth was a suitable time for the separation of the OHCs. At this time, the number of OHCs isolated from rats was large, and the cell morphology was typical of cylindrical shape. OHCs isolated using this method are histologically suitable and quantitatively adequate for molecular biological and electrophysiological analyses.