isolation-culture-primary-cochlear-hair-cells-from-neonatal

Isolation and Culture of Primary Cochlear Hair Cells from Neonatal Mice

Cochlear hair cells are the sensory receptors of the auditory system. These cells are located in the organ of Corti, the sensory organ responsible for ...

The Second Affiliated Hospital of Xi’an Jiaotong University

Allergic rhinitis (AR) is a common chronic inflammatory condition of the nasal mucosal tissue. Platycodin D (PLD), a triterpenoid saponin isolated from the root of Platycodon grandiflorum, has anti-inflammatory effects in a mouse model of allergic asthma. However, the anti-inflammatory effects of PLD in the nasal mucosa have not been deeply investigated. The objective was to investigate the effect of PLD on inflammatory cytokines and mucus production from nasal epithelial cells. Our study showed that PLD inhibited the levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and eotaxin in interleukin (IL)-13-stimulated RPMI2650 cells. PLD also suppressed IL-13-induced mucin 5AC (MUC5AC) expression in RPMI2650 cells. Moreover, PLD treatment prevented IL-13-induced p-NF-κB p65 expression in RPMI2650 cells, as well as MAPK signaling pathway activation. Taken together, our results provided evidence that PLD inhibits IL-13-induced the expression of inflammatory cytokines and mucus in nasal epithelial cells by inhibiting the activation of NF-κB and MAPK signaling pathways.

Platycodin D inhibits interleukin-13-induced the expression of inflammatory cytokines and mucus in nasal epithelial cells.

Malignant melanoma is an aggressive form of cancer which is highly resistant to chemotherapy. We have previously found that gambogic acid (GA), a kind of polyprenylated xanthone, exhibits an antitumour role in melanoma. The study was designed to investigate novel mechanisms of the antitumour effect of GA in melanoma cells and implanted nude mice. Gambogic acid significantly decreased cell viability, increased apoptosis and reduced migration and invasion in A375 cells. In addition, cisplatin-induced cytotoxicity in both A375 and A375/CDDP cells was increased by GA. The expression of miR-199a-3p was increased by GA in A375 cells and implanted tumours, and inhibition of miR-199a-3p significantly prevented GA-induced effect on cell viability, apoptosis, migration, invasion and cisplatin sensitivity in A375 cells. miR-199a-3p mimics reduced tumour weight and volume in vivo and decreased cell viability, increased apoptosis and reduced migration and invasion in vitro. miR-199a-3p expression was decreased in melanoma tissues and cells, as compared with their controls. miR-199a-3p possessed a potential binding site in the 3'-UTR of zinc finger E-box binding homeobox (ZEB1). ZEB1 expression was increased in melanoma tissues and cells, as compared with their controls. ZEB1 and miR-199a-3p expression was negatively correlated in melanoma tissues. The expression of ZEB1 was decreased by GA in A375 cells and implanted tumours, and up-regulation of ZEB1 significantly prevented GA-induced effect on cell viability, apoptosis, migration, invasion and cisplatin sensitivity. Down-regulation of ZEB1 reduced tumour weight and volume in vivo and decreased cell viability, increased apoptosis and reduced migration and invasion in vitro. We identified the important roles of miR-199a-3p and ZEB1 in melanoma and elucidated the tumour suppressor function of miR-199a-3p through inhibition of ZEB1. The results highlight the importance of miR-199a-3p-ZEB1 signalling in antitumour effect of GA in malignant melanoma and provide novel targets for the chemotherapy of melanoma.

Gambogic Acid Inhibits Melanoma through Regulation of miR-199a-3p/ZEB1 Signalling.

Aberrant proliferation and migration of airway smooth muscle cells (ASMCs) contribute to the pathogenesis of airway remodeling during asthma development. Here, the potential function of microRNA-217 (miR-217) on the cell proliferation and migration of TGF-β1-induced ASMCs and the involved mechanisms were investigated in this study. We found that miR-217 expression was apparently downregulated in a time and dose dependent characteristic in ASMCs exposed to transforming growth factor-β (TGF-β1) stimulation. Overexpression of miR-217 significantly inhibited TGF-β1-induced proliferation, migration, extracellular matrix (ECM) deposition, but promoted apoptosis in ASMCs, whereas, miR-217 inhibitor showed an opposed effect. Bioinformatics analyses revealed that the 3'-untranslated region (UTR) of ZEB1 was a potential target for miR-217, which was further confirmed by luciferase activity, qRT-PCR and western blot assay. In addition, rescue experiment also displayed that restoration of ZEB1 expression partially abrogated the inhibitory effect of miR-217 on TGF-β1-induced proliferation and migration in ASMCs. By chromatin immunoprecipitation (ChIP) assay, we further confirmed that the binding of ZEB1 to the fibronectin promoter in TGF-β1-treated ASMCs was reduced by miR-217 overexpression. Therefore, our findings suggested the potential protective role of miR-217 on the attenuation of cell proliferation and migration was through targeting ZEB1 in TGF-β1-stimulated ASMCs.

miR-217 represses TGF-β1-induced airway smooth muscle cell proliferation and migration through targeting ZEB1.

To understand the pathogenesis of cartilage damage in Kashin-Beck disease (KBD) and rheumatoid arthritis (RA) which similar clinical symptoms.

RNA-seq analysis reveals different gene ontologies and pathways in rheumatoid arthritis and Kashin-Beck disease.

Melanoma is the deadliest form of skin cancer and one of the most aggressive cancers. ZFAS1 is a newly identified lncRNA, playing an oncogenic role in several types of cancer. The present study aimed to investigate the function and mechanism of ZFAS1-induced regulation of melanoma. ZFAS1 expression was increased in melanoma tissues and cells compared with normal controls. ZFAS1 expression in metastatic tissues was higher than that in nonmetastatic subjects. Higher expression of ZFAS1 predicted lower survival rates. Knockdown of ZFAS1 decreased proliferation, increased apoptosis, decreased migration and invasion, and reduced epithelial-mesenchymal transition potential in melanoma cells. Moreover, ZFAS1 knockdown inhibited tumor growth in nude mice. There was a direct binding between ZFAS1 and miR-150-5p. ZFAS1 negatively regulated miR-150-5p expression and upregulation of miR-150-5p was involved in ZFAS1 knockdown-induced effect on proliferation, apoptosis, migration, and invasion. Using bioinformatics, we predicted the binding between RAB9A and miR-150-5p, and the direct interaction between RAB9A and miR-150-5p was confirmed by luciferase reporter and RNA immunoprecipitation assays. We also showed that RAB9A expression was regulated negatively by miR-150-5p, but was regulated positively by ZFAS1. Downregulation of RAB9A significantly inhibited the increase in proliferation, decrease in apoptosis, and increase in migration and invasion induced by miR-150-5p inhibitors. Moreover, RAB9A knockdown decreased proliferation, increased apoptosis, and decreased migration and invasion in melanoma cells. In summary, we confirmed the tumor-promoting role of ZFAS1 in melanoma and provide evidence for the role and mechanism of the ZFAS1/miR-150-5p/RAB9A axis. These findings may lead to novel therapeutic strategies for melanoma.

Long noncoding RNA ZFAS1 promotes tumorigenesis through regulation of miR-150-5p/RAB9A in melanoma.

Time restricted feeding (TRF), which is an intermittent fasting protocol, has been reported to decrease the toxicity and mortality rate associated with systemic gentamicin (GM) administration. The aim of this study is to evaluate the effect of TRF on GM-induced vestibular and auditory function in mice.

Beneficial effects of time-restricted feeding on gentamicin cytotoxicity in mouse cochlea and vestibular organs.

The aim of this study was to investigate the effects of pyrroloquinoline quinone (PQQ), an oxidoreductase cofactor, on the HO-induced premature senescence model in HEI-OC1 auditory cells and to elucidate its mechanism of action in vitro. Cells were treated with PQQ for 1 day before HO (100 μM) exposure. Mitochondrial respiratory capacity was damaged in this premature senescence model but was restored in cells pretreated with PQQ (0.1 nM or 1.0 nM). A decrease in mitochondrial potential, the promotion of mitochondrial fusion and the accelerated movement of mitochondria were all observed in PQQ-pretreated cells. The protein expression of sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) were significantly decreased under HO exposure while they were increased with PQQ pretreatment, and PGC-1α acetylation was significantly decreased. In conclusion, PQQ has a protective effect on the premature senescence model of HEI-OC1 auditory cells and is associated with the SIRT1/PGC-1α signaling pathway, mitochondrial structure, and mitochondrial respiratory capacity.

Pyrroloquinoline quinone (PQQ) protects mitochondrial function of HEI-OC1 cells under premature senescence.

We investigated whether the oxidoreductase cofactor pyrroloquinoline quinone (PQQ) prevents noise-induced and age-related hearing loss (NIHL and ARHL) in mice. To assess NIHL, 8 week-old mice with and without PQQ administration were exposed to noise for 4 h. PQQ was orally administered for one week before and after noise exposure and subcutaneously once before noise exposure. For ARHL evaluation, mice were given drinking water with or without PQQ starting at 2 months of age. In the NIHL model, PQQ-treated mice had auditory brainstem response (ABR) thresholds of significantly reduced elevation at 8 kHz, a significantly increased number of hair cells at the basal turn, and significantly better maintained synapses beneath the inner hair cells compared to controls. In the ARHL model, PQQ significantly attenuated the age-related increase in ABR thresholds at 8 and 32 kHz at 10 months of age compared to controls. In addition, the hair cells, spiral ganglion cells, ribbon synapses, stria vascularis and nerve fibers were all significantly better maintained in PQQ-treated animals compared to controls at 10 months of age. These physiological and histological results demonstrate that PQQ protects the auditory system from NIHL and ARHL in mice.

Effects of pyrroloquinoline quinone on noise-induced and age-related hearing loss in mice.

Author Correction: Pyrroloquinoline quinone (PQQ) protects mitochondrial function of HEI-OC1 cells under premature senescence.

Retraction notice to "miR-217 represses TGF-β1-induced airway smooth muscle cell proliferation and migration through targeting ZEB1 " [Biomed. Pharmacother. 108 (2018) 27-35].

Ying Gao

Department of Otolaryngology

The Second Affiliated Hospital of Xi’an Jiaotong University

Isolation and Culture of Primary Cochlear Hair Cells from Neonatal Mice