Ferrostatin-1 protects auditory hair cells from cisplatin-induced ototoxicity in vitro and in vivo.

Cisplatin is used in a wide variety of malignancies, but cisplatin-induced ototoxicity remains a major issue in clinical practice. Experimental evidence indicates that ferroptosis plays a key role in mediating the unwanted cytotoxicity effect caused by cisplatin. However, the role of ferroptosis in cisplatin-induced ototoxicity requires elucidation. Ferrostatin-1 (Fer-1) was identified as a potent inhibitor of ferroptosis and radical-trapping antioxidant with its ability to reduce the accumulation of lipid peroxides and chain-carrying peroxyl radicals. In the current study, we investigated the effects of Fer-1 in cisplatin-induced ototoxicity in in vitro, ex vivo, and in vivo models. We found, for the first time that Fer-1 efficiently alleviated cisplatin-induced cytotoxicity in HEI-OC1 cells via a concentration-dependent manner. Furthermore, Fer-1 mitigated cisplatin cytotoxicity in transgenic zebrafish sensory hair cells. In HEI-OC1 cells, Fer-1 pretreatment not only drastically reduced the generation of intracellular reactive oxygen species but also remarkably decreased lipid peroxidation levels induced by cisplatin. This was not only ascribed to the inhibition of 4-hydroxynonenal, the final product of lipid peroxides, but also to the promotion of glutathione peroxidase 4, the protein marker of ferroptosis. MitoTracker staining and transmission electron microscopy of mitochondrial morphology suggested that in HEI-OC1 cells, Fer-1 can effectively abrogate mitochondrial damage resulting from the interaction with cisplatin. In addition, Fer-1 pretreatment of cochlear explants substantially protected hair cells from cisplatin-induced damage. Therefore, our results demonstrated that ferroptosis might be involved in cisplatin ototoxicity. Fer-1 administration mitigated cisplatin-induced hair cell damage, further investigations are required to elucidate the molecular mechanisms of its otoprotective effect.

Trans-vaccenic acid inhibits proliferation and induces apoptosis of human nasopharyngeal carcinoma cells via a mitochondrial-mediated apoptosis pathway.

BACKGROUND: Intake of trans fatty acids (TFAs) from partially hydrogenated vegetable oil is associated with a variety of adverse outcomes, but little is known about the health effects of ruminant trans fats. Trans-vaccenic acid (TVA) is a naturally occurring TFA found in the fat of ruminants and in human dairy products. The present study was conducted to investigate the anticancer activity and underlying mechanisms of TVA on human nasopharyngeal carcinoma (NPC) 5-8F and CNE-2 cells. METHODS: A CCK8 assay was used to determine the effect of TVA and the Mcl-1 inhibitor S63845 on the proliferation of NPC cells. Apoptosis was measured using flow cytometry. Western blotting was used to detect the protein expression levels of factors associated with Bcl-2-family protein signaling and Akt signaling. RESULTS: TVA significantly inhibited cell proliferation in a dose-dependent manner. Mechanistic investigation demonstrated that TVA significantly decreased p-Akt levels and Bad phosphorylation on Ser-136 and Ser-112. More importantly, we discovered that the Mcl-1 inhibitor S63845 synergistically sensitized NPC cells to apoptosis induction by TVA. CONCLUSION: TVA can inhibit NPC cell growth and induced apoptosis through the inhibition of Bad/Akt phosphorylation. The combined use of TVA and Mcl-1 inhibitors offers a potential advantage for nasopharyngeal cancer treatment.

Characterization of the Transcriptome of Hair Cell Regeneration in the Neonatal Mouse Utricle.

BACKGROUND/AIMS: Hearing and balance deficits are mainly caused by loss of sensory inner ear hair cells. The key signals that control hair cell regeneration are of great interest. However, the molecular events by which the cellular signals mediate hair cell regeneration in the mouse utricle are largely unknown. METHODS: In the present study, we investigated gene expression changes and related molecular pathways using RNA-seq and qRT-PCR in the newborn mouse utricle in response to neomycin-induced damage. RESULTS: There were 302 and 624 genes that were found to be up-regulated and down-regulated in neomycin-treated samples. GO and KEGG pathway analyses of these genes revealed many deregulated cellular components, molecular functions, biological processes and signaling pathways that may be related to hair cell development. More importantly, the differentially expressed genes included 9 transcription factors from the zf-C2H2 family, and eight of them were consistently down-regulated during hair cell damage and subsequent regeneration. CONCLUSION: Our results provide a valuable source for future studies and highlighted some promising genes, pathways or processes that may be useful for therapeutic applications.

ABT-199-mediated inhibition of Bcl-2 as a potential therapeutic strategy for nasopharyngeal carcinoma.

BACKGROUND: Aberrant overexpression of Bcl-2 protein has been detected in 80% of nasopharyngeal carcinoma (NPC), and Bcl-2 family proteins are implicated in both NPC oncogenesis and chemotherapy resistance. Previous studies have shown that while treatment of NPC cells with Bcl-2 family inhibitors alone is rarely effective, concomitant treatment with a cytotoxic reagent such as cisplatin can increase efficacy through a synergistic effect. The aim of the current work was to determine how we might increase the efficacy of Bcl-2 family inhibitors in the absence of cytotoxic reagents, which are associated with negative side effect profiles. METHODS: We assessed cell proliferation in Bcl-2 high-expressing NPC cells by CCK-8 assay after treatment with the Bcl-2 inhibitor ABT-199 and/or the Mcl-1 inhibitor S63845. Apoptotic induction by ABT-199 was evaluated by Annexin V-FITC and PI double staining. We also evaluated Bcl-2 family protein expression (Bim, Mcl-1, Bcl-xL, Noxa) after treatment with ABT-199 by western blotting. Finally, xenografted Balb/c nude mice were used to test ABT-199 efficacy in vivo, H&E and immunohistochemistry assay were used to analyze tumor samples. RESULTS: ABT-199 effectively induced NPC cell apoptosis in vitro and in the xenograft model. Following ABT-199 treatment in NPC cells, upregulation of Mcl-1 and Bcl-xL can lead to drug resistance, while concomitant Noxa overexpression partially neutralized the Mcl-1-caused resistance. Given that ABT-199 induces apoptosis in NPC cells through the Bcl-2/Noxa/Mcl-1 axis, treatment avenues further targeting this pathway should be promising. Indeed, the newly developed Mcl-1 inhibitor S63845 in combination with ABT-199 had a synergistic effect on NPC cell apoptosis. CONCLUSION: Bcl-2 inhibition in NPC cells with ABT-199 triggers apoptosis through the Bcl-2/Noxa/Mcl-1 axis, and dual inhibition of the anti-apoptotic Bcl-2 family proteins Bcl-2 and Mcl-1 provided a strong synergistic effect without the need for adjunctive cytotoxic agent treatment with cisplatin.

Novel Application of Eupatilin for Effectively Attenuating Cisplatin-Induced Auditory Hair Cell Death via Mitochondrial Apoptosis Pathway.

Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is a pharmacologically active flavone that has been isolated from a variety of medicinal plants and possesses a number of pharmacological properties. This study evaluates the antioxidant and antiapoptotic effects of eupatilin on cisplatin-induced ototoxicity using in vitro and in vivo models including HEI-OC1 cells, cochlear hair cells, and zebrafish. Employing a CCK8 assay and Annexin V-FITC/PI double staining, we found that eupatilin significantly alleviated cisplatin-induced apoptosis and increased hair cell viability. The level of reactive oxygen species (ROS) was evaluated by CellROX green and MitoSOX Red staining. The results showed that eupatilin possesses antioxidant activity. MitoTracker Red staining indicated that eupatilin remarkably decreased mitochondrial damage. Furthermore, we demonstrated that eupatilin protects hair cells from cisplatin-induced damage. Mechanistic studies in cisplatin-induced HEI-OC1 cells revealed that eupatilin promoted Bcl-2 expression, downregulated Bax expression, reversed the increase in caspase-3 and PARP activity, and reduced the expression of phosphorylated p38 and JNK. Our data suggest a novel role for eupatilin as a protective agent against ototoxic drug-induced hair cell apoptosis by inhibiting ROS generation and modulating mitochondrial-related apoptosis.

Low-dose naloxone for prophylaxis of sufentanil-induced choking and postoperative nausea and vomiting.

Sufentanil, a potent opioid, serves as the first option for perioperative analgesia owing to its analgesic effect, long duration and stable hemodynamics, whereas its side effects frequently blunt its application. The intravenous (IV) injection of sufentanil during anesthesia induction has high incidence of choking or bucking reaction, which is defined as sufentanil-induced cough (SIC). Moreover, postoperative nausea and vomiting (PONV) is a common and stressful complication, which is also related to the usage of opioid. High incidence of PONV is reported in the patients with SIC. Hence, we sought to determine whether naloxone, an opioid antagonist, at low dose would decrease the incidences of SIC and PONV. 216 female patients undergoing gynecological laparoscopic operation (<2 h) under general anesthesia were recruited in this study, and randomly assigned into two groups: Group N (patients receiving naloxone and Group C (patients receiving vehicle). Sufentanil (0.5 µg/kg within 5 s) was given in anesthesia induction, and low-dose naloxone (1.25 µg/kg) or identical vehicle was initially injected 5 min prior to induction, with the incidence and severity of SIC estimated. Subsequently, naloxone or vehicle was continuously infused at the rate of 0.5 µg/kg/h in the initiation of operation until the end of the operation, and the transverse abdominal fascia block (TAP) was performed for postoperative analgesia. The PONV profiles such as incidence and the severity, grading, and the frequencies of antiemetic usage within 24 h were evaluated, with VAS scores and remedial measures for analgesia during the first 24 h postoperatively were recorded. Our results revealed that one bolus of low-dose naloxone prior to the induction significantly mitigated the incidence of SIC, and intraoperative continuous infusion of low-dose naloxone reduced the incidence and the severity of PONV, so that the postoperative VAS scores and further remedial analgesia were not altered. These results not only provide clinical solutions for prophylaxis of SIC and PONV, but also suggests that opioids may act as a key role in both SIC and PONV, whereas opioid antagonist may hit two tasks with one stone. Moreover, further investigations are required to address the underlying mechanism of SIC and PONV. Clinical Trial Registration: [www.chictr.org.cn], identifier [ChiCTR2200064865].

Erratum to "Liproxstatin-1 Protects Hair Cell-Like HEI-OC1 Cells and Cochlear Hair Cells against Neomycin Ototoxicity".

[This corrects the article DOI: 10.1155/2020/1782659.].

Identification of differentially expressed circular RNAs in human nasopharyngeal carcinoma.

BACKGROUND: Circular RNAs (circRNAs) are endogenous RNAs that have a covalent closed cycle configuration. circRNAs have been found to be differentially expressed in many human cancers. Therefore, circRNAs may be ideal biomarkers for the diagnosis and treatment of cancer. However, we know very little about the function of circRNAs in nasopharyngeal carcinoma (NPC). The purpose of this study was to evaluate the circRNA expression profiles in NPC. METHODS: We utilized high-throughput RNA sequencing (RNA-Seq) to evaluate the circRNA expression profile in NPC A total of 13,561 unique circRNA candidates were detected. Selection of aberrantly expressed circRNAs was carried out using a q-value of < 0.001 with a fold change of > 2.0 or < 0.5. We carried out Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses to identify the biological functions of differentially expressed circRNAs. Moreover, bioinformatics analyses were implemented to predict the effects between circRNAs and cancer-related microRNAs (miRNAs), and we used Cytoscape to build a cancer-related circRNA-miRNA target gene map. Finally, to verify dysregulated circRNAs, quantitative real-time PCR was utilized. RESULTS: In NPC tissues, we found that 73 circRNAs were downregulated and 59 were upregulated. The top 12 candidate circRNAs were selected from several vital NPC pathways such as the human papillomavirus and Epstein-Barr virus infection signaling pathways (hsa05165 and hsa05169, respectively), Hepatitis B (hsa05161), and the Ras signaling pathway (hsa04014). A network map of circRNA-miRNA interactions of 12 differentially expressed circRNAs was built. Hsa_circ_0007637 expression distinguished NPC tissues from paired healthy tissues and NPC cell lines (HNE1 6-10B, 5-8F, CNE-2, and so on) from a normal epithelial (NP460) cell line. CONCLUSIONS: In this study, we investigated the profiles of differentially expressed circRNAs in NPC, and our results show that hsa_circ_0007637 may be a biomarker for NPC and play a role in its development. This observation-based research identified dysregulated circRNAs in NPC, which may assist in the development of biomarkers for this disease. Further studies on the mechanisms and functions of these circRNAs may promote our understanding of NPC tumorigenesis.

Liproxstatin-1 Protects Hair Cell-Like HEI-OC1 Cells and Cochlear Hair Cells against Neomycin Ototoxicity.

Ferroptosis is a recently discovered iron-dependent form of oxidative programmed cell death distinct from caspase-dependent apoptosis. In this study, we investigated the effect of ferroptosis in neomycin-induced hair cell loss by using selective ferroptosis inhibitor liproxstatin-1 (Lip-1). Cell viability was identified by CCK8 assay. The levels of reactive oxygen species (ROS) were determined by DCFH-DA and cellROX green staining. The mitochondrial membrane potential (ΔΨm) was evaluated by TMRM staining. Intracellular iron and lipid peroxides were detected with Mito-FerroGreen and Liperfluo probes. We found that ferroptosis can be induced in both HEI-OC1 cells and neonatal mouse cochlear explants, as evidenced by Mito-FerroGreen and Liperfluo staining. Further experiments showed that pretreatment with Lip-1 significantly alleviated neomycin-induced increased ROS generation and disruption in ΔΨm in the HEI-OC1 cells. In parallel, Lip-1 significantly attenuated neomycin-induced hair cell damage in neonatal mouse cochlear explants. Collectively, these results suggest a novel mechanism for neomycin-induced ototoxicity and suggest that ferroptosis inhibition may be a new clinical intervention to prevent hearing loss.

Engineering cell signaling using tunable CRISPR-Cpf1-based transcription factors.

The catalytically dead Cpf1 endonuclease from Acidaminococcus sp. BV3L6 (dAsCpf1) has been used to construct effective transcriptional repressors in bacteria and plants. However, it is still unclear if dAsCpf1 can function in human cells as a transcriptional regulator or a signal conductor. Here, we repurpose the dAsCpf1 system in human cells for a variety of functions, including the activation or repression of gene transcription. Moreover, we construct programmable ligand-controlled dAsCpf1 systems either by coupling crRNAs with engineered riboswitches or by fusing dAsCpf1 proteins with G protein-coupled receptors. These generalizable approaches allow us to regulate the transcription of endogenous genes in response to diverse classes of ligands, thus constructing artificial signaling pathways with rewired cellular input-output behaviors. The systems exhibit signal amplification, an important feature in cell signaling, when multiple crRNAs are processed from a single transcript. The results provide a robust and efficient platform for engineering customized cell signaling circuits.

A micro-potentiometric hemoglobin immunosensor based on electropolymerized polypyrrole-gold nanoparticles composite.

We report a novel micro-potentiometric hemoglobin (Hb) immunosensor based on electrochemically synthesized polypyrrole (PPy)-gold nanoparticles (AuNPs) composite. PPy-AuNPs film with AuNPs uniformly distributed in it was deposited on gold electrode surface by a simple and direct procedure, without the addition of any nanoparticles or reducing agent. And this generic method makes it possible to deposite different polymers on miniaturized electrodes. With the existence of AuNPs, the antibody immobilization onto the electrode surface was facilitated. Morphology study by field emission scanning electron microscope (FE-SEM) confirms the presence of AuNPs in PPy. Based on an ion-sensitive field-effect transistors (ISFETs) integrated chip, a micro-potentiometric immunosensor for Hb and hemoglobin-A1c (HbA1c) has been constructed. The sensor response was linear over the concentration range 60-180 microg/ml Hb and 4-18 microg/ml HbA1c. The Hb concentration in whole blood samples has also been analysed, with a linear dose-response behavior between 125 and 197 microg/ml and a sensitivity of 0.20 mV microg(-1)ml. The measuring ranges of the developed Hb and HbA1c immunosensors meet the clinical demand for measuring the HbA1c/Hb ratio of 5-20%. This sensor results in simple and rapid differential measurement of Hb and HbA1c, and has great potential to become an inexpensive and portable device for monitoring of diabetes.