PTHrP participates in the bone destruction of middle ear cholesteatoma via promoting macrophage differentiation into osteoclasts induced by RANKL. / PTHrP促进RANKLè¯±å¯¼å·¨å™¬ç»†èƒžåˆ†åŒ–ä¸ºç ´éª¨ç»†èƒžå‚ä¸Žä¸­è€³èƒ†è„‚ç˜¤éª¨ç ´å.

OBJECTIVES: Progressive bone resorption and destruction is one of the most critical clinical features of middle ear cholesteatoma, potentially leading to various intracranial and extracranial complications. However, the mechanisms underlying bone destruction in middle ear cholesteatoma remain unclear. This study aims to explore the role of parathyroid hormone-related protein (PTHrP) in bone destruction associated with middle ear cholesteatoma. METHODS: A total of 25 cholesteatoma specimens and 13 normal external auditory canal skin specimens were collected from patients with acquired middle ear cholesteatoma. Immunohistochemical staining was used to detect the expressions of PTHrP, receptor activator for nuclear factor-kappa B ligand (RANKL), and osteoprotegerin (OPG) in cholesteatoma and normal tissues. Tartrate-resistant acid phosphatase (TRAP) staining was used to detect the presence of TRAP positive multi-nucleated macrophages in cholesteatoma and normal tissues. Mono-nuclear macrophage RAW264.7 cells were subjected to interventions, divided into a RANKL intervention group and a PTHrP+ RANKL co-intervention group. TRAP staining was used to detect osteoclast formation in the 2 groups. The mRNA expression levels of osteoclast-related genes, including TRAP, cathepsin K (CTSK), and nuclear factor of activated T cell cytoplasmic 1 (NFATc1), were measured using real-time polymerase chain reaction (real-time PCR) after the interventions. Bone resorption function of osteoclasts was assessed using a bone resorption pit analysis. RESULTS: Immunohistochemical staining showed significantly increased expression of PTHrP and RANKL and decreased expression of OPG in cholesteatoma tissues (all P<0.05). PTHrP expression was significantly positively correlated with RANKL, the RANKL/OPG ratio, and negatively correlated with OPG expression (r=0.385, r=0.417, r=-0.316, all P<0.05). Additionally, the expression levels of PTHrP and RANKL were significantly positively correlated with the degree of bone destruction in cholesteatoma (r=0.413, r=0.505, both P<0.05). TRAP staining revealed a large number of TRAP-positive cells, including multi-nucleated osteoclasts with three or more nuclei, in the stroma surrounding the cholesteatoma epithelium. After 5 days of RANKL or PTHrP+RANKL co-intervention, the number of osteoclasts was significantly greater in the PTHrP+RANKL co-intervention group than that in the RANKL group (P<0.05), with increased mRNA expression levels of TRAP, CTSK, and NFATc1 (all P<0.05). Scanning electron microscopy of bone resorption pits showed that the number (P<0.05) and size of bone resorption pits on bone slices were significantly greater in the PTHrP+RANKL co-intervention group compared with the RANKL group. CONCLUSIONS: PTHrP may promote the differentiation of macrophages in the surrounding stroma of cholesteatoma into osteoclasts through RANKL induction, contributing to bone destruction in middle ear cholesteatoma.

Microarray analysis and functional prediction of differentially expressed circular RNAs in acquired middle ear cholesteatoma.

BACKGROUND: Middle ear cholesteatoma is characterized by hyper-proliferation of keratinocytes. Circular RNA (circRNA) plays an essential role in the pathogenesis of many proliferative diseases. However, the role of circRNA in the etiopathogenesis of middle ear cholesteatoma is rarely investigated so far. We aimed to investigate the differential expression profiling of circRNAs between acquired middle ear cholesteatoma and normal skin, and to identify potential circRNAs contributing to the etiopathogenesis of middle ear cholesteatoma. Microarray analysis and functional prediction were performed to investigate the circRNA expression profiling between middle ear cholesteatoma and normal skin. Validation of differentially expressed circRNAs was conducted by qRT-PCR. Prediction of m6A modification was also carried out. RESULTS: Microarray analysis displayed that totally 93 up-regulated and 85 down-regulated circRNAs were identified in middle ear cholesteatoma. Through validation, expressions of hsa_circRNA_104327 and hsa_circRNA_404655 were significantly higher, while hsa_circRNA_000319 was significantly down-regulated in cholesteatoma. GO classification, KEGG pathway, and ceRNA network analyses suggested that these differentially expressed circRNAs might play important roles in the etiopathogenesis of middle ear cholesteatoma. Prediction of m6A modification exhibited that hsa_circRNA_000319 possessed 4 m6A sites with very high confidence, and hsa_circRNA_404655 had 3 m6A sites with high confidence. CONCLUSIONS: Our study revealed that these differentially expressed circRNAs might contribute to the etiopathogenesis of middle ear cholesteatoma. Further researches should be conducted to investigate the exact mechanism of these differentially expressed circRNAs in the etiopathogenesis of middle ear cholesteatoma. Targeting on these circRNAs may provide a new strategy for middle ear cholesteatoma therapy in the future.

Circle RNA hsa_circRNA_100290 serves as a ceRNA for miR-378a to regulate oral squamous cell carcinoma cells growth via Glucose transporter-1 (GLUT1) and glycolysis.

Aerobic glycolysis (the Warburg effect) is a robust metabolic hallmark of most tumors, including oral squamous cell carcinoma (OSCC). Glucose transporter 1 (GLUT1), a major glucose transporter regulating the glucose uptake, is upregulated in OSCC and participated in the cell glycolysis of OSCC. The deregulation and function of noncoding RNAs in cancers have been widely reported. Reportedly, hsa_circular RNA (circRNA)_100290 (circ_SLC30A7) is significantly upregulated (fold change = 6.91, p < 0.0000001) in OSCC. According to online tools prediction (miRWalk, miRanda, and Targetscan), miR-378a could simultaneously target circRNA_100290 and GLUT1. Herein, the expression of circRNA_100290 and GLUT1 remarkably increased in oral tumor tissue specimens and cells. In OSCC cell lines, cell proliferation and glycolysis could be remarkably downregulated by circRNA_100290 silence, which could be rescued by GLUT1 overexpression. Conversely, miR-378a expression could be remarkably inhibited in tumor tissue specimens and cells. The effect of miR-378a overexpression on OSCC cells was similar to those of circRNA_100290 silence. miR-378a directly bound to circRNA_100290 and GLUT1 3'-untranslated region, circRNA_100290 could remarkably relieve miR-378a-induced inhibition on GLUT1 via acting as a competing endogenous RNA (ceRNA). miR-378a inhibition remarkably attenuated the effect of circRNA_100290 silence on cell proliferation and glycolysis in OSCC cell lines. In summary, circRNA_100290 serves as a ceRNA to counteract miR-378a-mediated GLUT1 suppression, thus promoting glycolysis and cell proliferation in OSCC. We provide a reliable experimental basis for understanding the mechanism of cell growth and glycolysis deregulation in OSCC.

Microarray Analysis of Differentially-expressed MicroRNAs in Acquired Middle Ear Cholesteatoma.

Objectives: To analyze the miRNAs expression profiling between acquired middle ear cholesteatoma and normal skin, and to identify several novel miRNAs which may be involved in the etiopathogenesis of middle ear cholesteatoma. Methods: MiRNA microarray technology was adopted to analyze the miRNA expression profiling between acquired middle ear cholesteatoma and normal skin. qRT-PCR was used to validate selected differentially expressed miRNAs. Results: The miRNA microarray technology showed totally 44 upregulated (miRNA-21-3p, miRNA-584-5p, miRNA-16-1-3p, etc) and 175 downregulated (miRNA-10a-5p, miRNA-152-5p, miRNA-203b-5p, etc) miRNAs in cholesteatoma tissues with 2-fold change compared with normal skin. The qRT-PCR validation was in accordance with the microarray results partly: miRNA-21-3p and miRNA-16-1-3p expressed significantly higher while miRNA-10a-5p exhibited an obviously decreased expression in middle ear cholesteatoma tissues when compared with normal skin. The GO and KEGG pathway analyses provided clues that these differentially expressed miRNAs might play essential roles in the etiopathogenesis of middle ear cholesteatoma, including cell proliferation, apoptosis, cell cycle, differentiation, bone resorption and remodeling process. Conclusions: Our study suggests possible roles of differentially expressed miRNAs in the pathogenesis of middle ear cholesteatoma. Targeting on these miRNAs may provide a new strategy for cholesteatoma therapy in the future.

The role of bone resorption in the etiopathogenesis of acquired middle ear cholesteatoma.

Cholesteatoma is a destructive squamous epithelial lesion of the temporal bone which gradually expands and leads to serious complications by destruction of nearby bony structures. Erosion caused by bone resorption of the ossicular chain and bony labyrinth may result in hearing loss, vestibular dysfunction, facial paralysis, labyrinthine fistulae and intracranial complications. The exact underlying cellular and molecular mechanism of bone resorption in acquired cholesteatoma still remains unexplained. Pubmed database and China National Knowledge Infrastructure were screened for articles focusing on bone resorption in acquired cholesteatoma. Osteoclast activation, pressure necrosis, acid lysis, enzyme mediation, inflammatory mediators and several newly discovered biomolecules are outlined as main theories behind bone resorption in acquired cholesteatoma, aiming to facilitate the development of potential therapeutic targets for preventing intracranial and extracranial complications caused by bone resorption in acquired middle ear cholesteatoma.

Activation of the EGFR/Akt/NF-κB/cyclinD1 survival signaling pathway in human cholesteatoma epithelium.

Cholesteatoma is a benign keratinizing squamous epithelial lesion characterized by the hyper-proliferation of keratinocytes with abundant production of keratin debris in the middle ear. The epidermal growth factor receptor (EGFR)/Akt/nuclear factor-kappa B (NF-κB)/cyclinD1 signaling pathway is one of the most important pathways in regulating cell survival and proliferation. We hypothesized that the EGFR/Akt/NF-κB/cyclinD1 signaling pathway may be activated and involved in the cellular hyperplasia mechanism in acquired cholesteatoma epithelium. Immunohistochemical staining of phosphorylated EGFR (p-EGFR), phosphorylated Akt (p-Akt), activated NF-κB and cyclinD1 protein was performed in 40 cholesteatoma samples and 20 samples of normal external auditory canal (EAC) epithelium. Protein expression of p-EGFR, p-Akt, activated NF-κB and cyclinD1 in cholesteatoma epithelium was significantly increased when compared with normal EAC epithelium (p < 0.01). In cholesteatoma epithelium, a significant positive association was observed between p-EGFR and p-Akt expression and between the expressions of p-Akt and NF-κB, NF-κB and cyclinD1, respectively (p < 0.01). No significant relationships were observed between the levels of investigated proteins and the degree of bone destruction (p > 0.05). The increased protein expression of p-EGFR, p-Akt, NF-κB and cyclinD1 and their associations in cholesteatoma epithelium suggest that the EGFR/Akt/NF-κB/cyclinD1 survival signaling pathway is active and may be involved in the regulatory mechanisms of cellular hyperplasia in cholesteatoma epithelium.

The role of EGFR/PI3K/Akt/cyclinD1 signaling pathway in acquired middle ear cholesteatoma.

Cholesteatoma is a benign keratinizing and hyper proliferative squamous epithelial lesion of the temporal bone. Epidermal growth factor (EGF) is one of the most important cytokines which has been shown to play a critical role in cholesteatoma. In this investigation, we studied the effects of EGF on the proliferation of keratinocytes and EGF-mediated signaling pathways underlying the pathogenesis of cholesteatoma. We examined the expressions of phosphorylated EGF receptor (p-EGFR), phosphorylated Akt (p-Akt), cyclinD1, and proliferating cell nuclear antigen (PCNA) in 40 cholesteatoma samples and 20 samples of normal external auditory canal (EAC) epithelium by immunohistochemical method. Furthermore, in vitro studies were performed to investigate EGF-induced downstream signaling pathways in primary external auditory canal keratinocytes (EACKs). The expressions of p-EGFR, p-Akt, cyclinD1, and PCNA in cholesteatoma epithelium were significantly increased when compared with those of control subjects. We also demonstrated that EGF led to the activation of the EGFR/PI3K/Akt/cyclinD1 signaling pathway, which played a critical role in EGF-induced cell proliferation and cell cycle progression of EACKs. Both EGFR inhibitor AG1478 and PI3K inhibitor wortmannin inhibited the EGF-induced EGFR/PI3K/Akt/cyclinD1 signaling pathway concomitantly with inhibition of cell proliferation and cell cycle progression of EACKs. Taken together, our data suggest that the EGFR/PI3K/Akt/cyclinD1 signaling pathway is active in cholesteatoma and may play a crucial role in cholesteatoma epithelial hyper-proliferation. This study will facilitate the development of potential therapeutic targets for intratympanic drug therapy for cholesteatoma.

Intratympanic dexamethasone perfusion versus injection for treatment of refractory sudden sensorineural hearing loss.

Intratympanic steroid treatment for the sudden sensorineural hearing loss (SSNHL) has a long history and many techniques have been developed. The efficacies are varied in different studies owing to different criteria, steroid type and dose, delivery methods, or absence of comparison groups. Recently, animal experiments suggested that continuous delivery systems produce the higher inner ear drug concentrations than other ways. This study was aimed at evaluating the efficacies of intratympanic dexamethasone perfusion versus injection for treatment of refractory sudden sensorineural hearing loss (RSSNHL). A total of 136 patients were enrolled in this nonrandomized, prospective, controlled study. Thirty-two patients were treated with continuous intratympanic dexamethasone perfusion via round window microcatheter by an electronic pump at a rate of 10 µl/min twice daily for 7 days and 34 patients underwent intratympanic dexamethasone injection of the same dosage. Seventy patients who refused to undertake further treatment were selected as a control group. Pure-tone audiometry results were obtained before and after treatments. Minimum follow-up time from the last treatment was 1 month. There were no serious adverse events in the treatment groups. Hearing improvement rate (HIR) of SSNHL in perfusion group was 40.6 %, which was significantly higher than in the injection and control groups (20.6 and 7.7 %, respectively). HIR had no relation with sex, age, and associated symptoms. Results indicated that intratympanic dexamethasone perfusion by external electronic pump with gelatin sponge placement in round window niche is an efficacious and safe method for the treatment of RSSNHL, showing superiority to simple injection through the drum.

Efficacy of endoscopic porcine small intestinal submucosa graft myringoplasty: a retrospective comparative study.

BACKGROUND: The surgical outcomes following tympanic membrane (TM) repair are affected by many factors. OBJECTIVES: To evaluate the efficacy of endoscopic porcine small intestine submucosa graft (PSISG) myringoplasty by comparing with endoscopic myringoplasty with temporal fascia (TF) and perichondrium (PC). METHODS: We conducted a retrospective comparative study that a total of 98 patients with TM perforations were included. The patients underwent endoscopic myringoplasty using PSISG, TF or PC as the graft. The closure rate, hearing outcomes, operative time and complications in three groups were compared. RESULTS: At 3 months postoperatively, the closure rate were 85.2% (23/27), 92.1% (35/38) and 87.9% (29/33) in the PSISG, TF and PC groups respectively (p = .667); Hearing improved after surgery in three groups (p < .001), and showed no significant difference among the three groups. The mean operative time of the PSISG group was shorter than autologous TF (p < .001) and PC groups (p < .001) in this study; No operative or postoperative complications were found among the three groups. CONCLUSION: Compare to autologous temporal fascia or perichondrium, the PSISG appears to be an effective and safe material for TM perforations closure. Endoscopic PSISG myringoplasty may be an alternative technique for repairing TM perforations, especially for revision cases.

Analysis of mRNA m6A modification and mRNA expression profiles in middle ear cholesteatoma.

Introduction: Middle ear cholesteatoma is characterized by the hyperproliferation of keratinocytes. In recent decades, N6-methyladenosine (m6A) modification has been shown to play an essential role in the pathogenesis of many proliferative diseases. However, neither the m6A modification profile nor its potential role in the pathogenesis of middle ear cholesteatoma has currently been investigated. Therefore, this study aimed to explore m6A modification patterns in middle ear cholesteatoma. Materials and methods: An m6A mRNA epitranscriptomic microarray analysis was performed to analyze m6A modification patterns in middle ear cholesteatoma tissue (n = 5) and normal post-auricular skin samples (n = 5). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to predict the potential biological functions and signaling pathways underlying the pathogenesis of middle ear cholesteatoma. Subsequently, m6A modification levels were verified by methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) in middle ear cholesteatoma tissue and normal skin samples, respectively. Results: A total of 6,865 distinctive m6A-modified mRNAs were identified, including 4,620 hypermethylated and 2,245 hypomethylated mRNAs, as well as 9,162 differentially expressed mRNAs, including 4,891 upregulated and 4,271 downregulated mRNAs, in the middle ear cholesteatoma group relative to the normal skin group. An association analysis between methylation and gene expression demonstrated that expression of 1,926 hypermethylated mRNAs was upregulated, while expression of 2,187 hypomethylated mRNAs and 38 hypermethylated mRNAs was downregulated. Moreover, GO analysis suggested that differentially methylated mRNAs might influence cellular processes and biological behaviors, such as cell differentiation, biosynthetic processes, regulation of molecular functions, and keratinization. KEGG pathway analysis demonstrated that the hypermethylated transcripts were involved in 26 pathways, including the Hippo signaling pathway, the p53 signaling pathway, and the inflammatory mediator regulation of transient receptor potential (TRP) channels, while the hypomethylated transcripts were involved in 13 pathways, including bacterial invasion of epithelial cells, steroid biosynthesis, and the Hippo signaling pathway. Conclusion: Our study presents m6A modification patterns in middle ear cholesteatoma, which may exert regulatory roles in middle ear cholesteatoma. The present study provides directions for mRNA m6A modification-based research on the epigenetic etiology and pathogenesis of middle ear cholesteatoma.

Aggressive sinonasal natural killer/T-cell lymphoma mimicking refractory sinusitis in a 4-year-old boy.

Pediatric patients with nasal symptoms are common, and most of them usually have inflammatory diseases, such as sinusitis, chronic rhinitis, nasal polyp, or adenotonsillar hypertrophy. Rarely, however, these inflammatory symptoms may be associated with more sinister pathology. Recently, we experienced a case of a 4-year-old boy with sinonasal natural killer (NK)/T-cell lymphoma whose initial symptoms were of nasal obstruction and mucopurulent nasal discharge.

Effectiveness of salvage intratympanic dexamethasone treatment for refractory sudden sensorineural hearing loss classified by audiogram patterns.

BACKGROUND: Intratympanic dexamethasone is commonly conducted to treat refractory sudden sensorineural hearing loss (RSSNHL). However, no consensus has been reached on its effectiveness. OBJECTIVES: The study aimed to evaluate the effectiveness of otoendoscope-assisted salvage intratympanic dexamethasone treatment (IDT) on RSSNHL with different audiogram patterns after failure of initial therapy. MATERIAL AND METHODS: A total of 108 patients with unilateral RSSNHL were classified into 4 groups according to audiogram patterns. Hearing results were evaluated by pure-tone audiometry (PTA), which was performed at baseline and one month after otoendoscope-assisted salvage IDT. The effectiveness of otoendoscope-assisted salvage IDT was assessed in each group. RESULTS: The efficiency in low-frequency, high-frequency, flat, and deaf group was 48%, 24.1%, 46.2%, 17.9%, respectively. The efficacy did not differ between the high-frequency and deaf group. Notably, the efficacy in the low-frequency and flat group was significantly higher than that in the deaf group. CONCLUSIONS: Otoendoscope-assisted salvage IDT is a safe and effective treatment for RSSNHL. This treatment provided better results for patients with low-frequency damaged and flat curve audiogram than patients with other audiogram patterns. SIGNIFICANCE: Audiogram patterns should be considered in the clinical management of patients with RSSHNL prior to salvage IDT.

Nuclear factor E2 related factor (NRF2) inhibits mast cell- mediated allergic inflammation via SIRT4-mediated mitochondrial metabolism.

BACKGROUND: Mast cell (MC)-mediated inflammation is essential for allergic rhinitis, and nuclear factor E2 related factor (NRF2) is found to inhibit inflammation. This study investigated whether NRF2 could inhibit MC inflammation and its molecular mechanisms concerning SIRT4. METHODS: Real-time quantitative PCR (RT-qPCR) and western blot were used to detect gene expression, and Elisa kit was used to detect the content of histamine and inflammatory cytokines in the medium of MCs, and Seahorse XF instrument was used to measure the mitochondrial metabolism of MCs. Knockdown SIRT4 and establish SIRT4 overexpression of HMC-1 cells to study the function of SIRT4. RESULTS: As an activator of NRF2, 4-Octyl Itaconate increases not only NRF2 expression but also increases SIRT4 expression. Although 4-Octyl Itaconate could reduce the histamine release and degranulation of MCs, which was induced by compound 48/80, SIRT4 knockdown decreased the inhibition of 4-Octyl Itaconate. Similarly,4-Octyl Itaconate inhibited the secretion of inflammatory cytokines (TNF-α, IL-1ß, IL6, and IL-8) by MCs, which was induced by LPS, but SIRT4 knockdown decreases the inhibition of 4-Octyl Itaconate. Also, the up-regulation of SIRT4 significantly inhibited mitochondrial metabolism in MCs and inhibited SIRT1 and P-p65 protein expression after inducing by 100 ng/mL LPS for 1 hour. CONCLUSIONS: NRF2 inhibits MC degranulation and MC-mediated inflammation by promoting SIRT4, and SIRT4 overexpression inhibits the mitochondrial metabolism of MCs.

Expression of PTHrP and RANKL in acquired middle ear cholesteatoma epithelium.

Background: Regarded as the most important clinical characteristic of middle ear cholesteatoma, the exact mechanism of bone resorption in cholesteatoma still remains unknown.Objectives: To investigate protein expression of PTHrP and RANKL in acquired middle ear cholesteatoma epithelium and analyze their functional roles in the etiopathogenesis of bone resorption in middle ear cholesteatoma.Material and methods: A total of 22 patients who underwent surgical treatment for middle ear cholesteatoma were recruited in the study. Protein expression of PTHrP and RANKL in middle ear cholesteatoma and normal postauricular skin was investigated by immunohistochemical staining. Correlations between bone resorption degree and expression of PTHrP and RANKL were also analyzed.Results: Protein expression of PTHrP and RANKL in cholesteatoma epithelium significantly increased when compared with normal postauricular skin epithelium. In cholesteatoma epithelium, a significantly positive association was observed between PTHrP and RANKL expression. Meanwhile, obviously positive correlations between protein expression of PTHrP and RANKL and bone resorption degree were discovered.Conclusions and significance: The increased protein expression of PTHrP and RANKL in cholesteatoma epithelium, and their associations with the degree of bone resorption, revealing that PTHrP might promote bone resorption process in middle ear cholesteatoma through RANKL signaling pathway.

Otoprotective Effects of Stephania tetrandra S. Moore Herb Isolate against Acoustic Trauma.

Noise is the most common occupational and environmental hazard, and noise-induced hearing loss (NIHL) is the second most common form of sensorineural hearing deficit. Although therapeutics that target the free-radical pathway have shown promise, none of these compounds is currently approved against NIHL by the United States Food and Drug Administration. The present study has demonstrated that tetrandrine (TET), a traditional Chinese medicinal alkaloid and the main chemical isolate of the Stephania tetrandra S. Moore herb, significantly attenuated NIHL in CBA/CaJ mice. TET is known to exert antihypertensive and antiarrhythmic effects through the blocking of calcium channels. Whole-cell patch-clamp recording from adult spiral ganglion neurons showed that TET blocked the transient Ca2+ current in a dose-dependent manner and the half-blocking concentration was 0.6 + 0.1 µM. Consistent with previous findings that modulations of calcium-based signaling pathways have both prophylactic and therapeutic effects against neural trauma, NIHL was significantly diminished by TET administration. Importantly, TET has a long-lasting protective effect after noise exposure (48 weeks) in comparison to 2 weeks after noise exposure. The otoprotective effects of TET were achieved mainly by preventing outer hair cell damage and synapse loss between inner hair cells and spiral ganglion neurons. Thus, our data indicate that TET has great potential in the prevention and treatment of NIHL.

HB-EGF expression as a potential biomarker of acquired middle ear cholesteatoma.

CONCLUSIONS: The heparin-binding epidermal growth factor-like growth factor (HB-EGF) plays an essential role in the development and invasiveness of cholesteatoma. This study may help to realize the molecular mechanisms underlying the pathogenesis of cholesteatoma and make HB-EGF a promising target for drug intervention of cholesteatoma. OBJECTIVE: To detect HB-EGF expression in human surgical specimens of acquired middle ear cholesteatoma and analyze its functional role as a regulator of epithelial keratinocytes hyperproliferation. METHODS: A total of 34 patients who underwent surgical treatment for middle ear cholesteatoma were recruited in the study. The mRNA and protein expression of HB-EGF in middle ear cholesteatoma tissues and normal postauricular skin tissues was investigated by real-time quantitative reverse-transcription-polymerase chain reaction (RT-qPCR), immunohistochemical staining, and western blot. The correlation between bone resorption degree and HB-EGF expression was also analyzed. RESULTS: On average, compared with normal postauricular skin, expression of HB-EGF mRNA in the cholesteatoma epithelium was significantly elevated 2.41-fold by RT-qPCR, and HB-EGF protein significantly upregulated 2.32-fold by western blot. Positive HB-EGF immunostaining observed in the basal and suprabasal layers of cholesteatoma epithelium was significantly stronger than in normal postauricular skin. Meanwhile, an obviously positive correlation between HB-EGF protein expression and bone resorption degree was discovered.

Acquired cholesteatoma epithelial hyperproliferation: Roles of cell proliferation signal pathways.

OBJECTIVES/HYPOTHESIS: To review the recent cell proliferation signal pathways in the etiopathogenesis of acquired middle ear cholesteatoma. DATA SOURCES: PubMed (to September 2015). REVIEW METHODS: Articles about cell proliferation signal pathways in the etiopathogenesis of acquired cholesteatoma and treatment advances were searched in the PubMed database, from which 73 were included in this review. RESULTS: The exact underlying cellular and molecular mechanism of acquired cholesteatoma still remains unknown. Recent research tends to regard the proliferation of cholesteatoma epithelial cells as the mechanism of cholesteatoma pathogenesis. Cell proliferation signal pathways including epidermal growth factor receptor/phosphoinositide 3-kinase/protein kinase B signal pathway, mitogen-activated protein kinase signal pathway, interleukin-6/signal transducer and activator of transcription 3 signal pathway, inhibitor of DNA binding/differentiation-1/nuclear factor-κB/cyclinD1 signal pathway, microRNA-mediated proliferation signal pathway, and keratinocyte growth factor/keratinocyte growth factor receptor signal pathway have been proven to play important roles in acquired middle ear cholesteatoma. CONCLUSIONS: This review outlines the main biological properties of certain cell proliferation signal pathways, aiming to facilitate the development of potential therapeutic targets for intratympanic drug therapy for the nonsurgical or complementary treatment of cholesteatoma. LEVEL OF EVIDENCE: NA Laryngoscope, 126:1923-1930, 2016.

DAPT mediates atoh1 expression to induce hair cell-like cells.

Hearing loss is currently an incurable degenerative disease characterized by a paucity of hair cells (HCs), which cannot be spontaneously replaced in mammals. Recent technological advancements in gene therapy and local drug delivery have shed new light for hearing loss. Atoh1, also known as Math1, Hath1, and Cath1, is a proneural basic helix-loop-helix (bHLH) transcription factor that is essential for HC differentiation. At various stages in development, Atoh1 activity is sufficient to drive HC differentiation in the cochlea. Thus, Atoh1 related gene therapy is the most promising option for HC induction. DAPT, an inhibitor of Notch signaling, enhances the expression of Atoh1 indirectly, which in turn promotes the induction of a HC fate. Here, we show that DAPT cooperates with Atoh1 to synergistically promote HC fate in ependymal cells in vitro and promote hair cell regeneration in the cultured basilar membrane (BM) which mimics the microenvironment in vivo. Taken together, our findings demonstrated that DAPT is sufficient to induce HC-like cells via enhancing of the expression of Atoh1 to inhibit the progression of HC apoptosis and to induce new HC formation.