Reorganization of H3K9me heterochromatin leads to neuronal impairment via the cascading destruction of the KDM3B-centered epigenomic network.

Histone H3K9 methylated heterochromatin silences repetitive non-coding sequences and lineage-specific genes during development, but how tissue-specific genes escape from heterochromatin in differentiated cells is unclear. Here, we examine age-dependent transcriptomic profiling of terminally differentiated mouse retina to identify epigenetic regulators involved in heterochromatin reorganization. The single-cell RNA sequencing analysis reveals a gradual downregulation of Kdm3b in cone photoreceptors during aging. Disruption of Kdm3b (Kdm3b +/- ) of 12-month-old mouse retina leads to the decreasing number of cones via apoptosis, and it changes the morphology of cone ribbon synapses. Integration of the transcriptome with epigenomic analysis in Kdm3b +/- retinas demonstrates gains of heterochromatin features in synapse assembly and vesicle transport genes that are downregulated via the accumulation of H3K9me1/2. Contrarily, losses of heterochromatin in apoptotic genes exacerbated retinal neurodegeneration. We propose that the KDM3B-centered epigenomic network is crucial for balancing of cone photoreceptor homeostasis via the modulation of gene set-specific heterochromatin features during aging.

Concurrent loss of LKB1 and KEAP1 enhances SHMT-mediated antioxidant defence in KRAS-mutant lung cancer.

Non-small-cell lung cancer (NSCLC) with concurrent mutations in KRAS and the tumour suppressor LKB1 (KL NSCLC) is refractory to most therapies and has one of the worst predicted outcomes. Here we describe a KL-induced metabolic vulnerability associated with serine-glycine-one-carbon (SGOC) metabolism. Using RNA-seq and metabolomics data from human NSCLC, we uncovered that LKB1 loss enhanced SGOC metabolism via serine hydroxymethyltransferase (SHMT). LKB1 loss, in collaboration with KEAP1 loss, activated SHMT through inactivation of the salt-induced kinase (SIK)-NRF2 axis and satisfied the increased demand for one-carbon units necessary for antioxidant defence. Chemical and genetic SHMT suppression increased cellular sensitivity to oxidative stress and cell death. Further, the SHMT inhibitor enhanced the in vivo therapeutic efficacy of paclitaxel (first-line NSCLC therapy inducing oxidative stress) in KEAP1-mutant KL tumours. The data reveal how this highly aggressive molecular subtype of NSCLC fulfills their metabolic requirements and provides insight into therapeutic strategies.

Surgical technique for complicated preauricular sinus: Pilot study of double elliptical excision with coaptation suture.

OBJECTIVES: Preauricular sinus (PAS) is a congenital anomaly that can progress to complicated cases with granulation tissue around the PAS area due to skin inflammation. Treatment involves incision and drainage or continuous dressing; however, surgical treatment may be necessary. We evaluated a surgical method for the effective treatment of complicated PAS. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 152 patients with PAS who were treated at a tertiary medical institution between September 2015 and June 2022. Data regarding age, sex, preoperative history related to PAS, a joint operation with a plastic surgeon, operation time, admission duration, follow-up duration, and postoperative complications were collected. The study population was divided into single-excision and double-excision with coaptation suture groups. The clinical characteristics were analyzed and compared between the two groups. RESULTS: Surgical treatment for PAS was performed in 131 patients (166 ears) in the single-excision group and 21 patients (27 ears) in the double-excision group. The average age was 6.22 ± 4.06 years old, and the male-to-female ratio was similar in the single-excision group (M:F = 68:63) but higher for females in the double-excision group (M:F = 5:16) (p = 0.017). Joint surgeries with a plastic surgeon were more frequent in the double-excision group, and the operation time and admission duration were significantly longer. The preoperative history and postoperative complications (seven cases, 4.6 %) did not differ significantly between the two groups, although there was a higher percentage of complications in the double elliptical excision group. CONCLUSIONS: Double excision with one or more coaptation sutures is an effective one-step method for complicated PAS with an acceptable aesthetic appearance of the scar, although it requires a longer operation time and admission duration for wound care. Further studies with larger and more diverse patient populations are needed to validate these findings.

Transcanal endoscopic ear surgery for glomus tympanicum removal: A case series on the necessity of preoperative embolization.

BACKGROUND: Transcanal endoscopic ear surgery (TEES) has become popular in recent years in the treatment of glomus tympanicum tumors (GTT). The most significant risk for TEES is bleeding. In some cases, preoperative vascular embolization is performed to mitigate bleeding during TEES. However, guidelines regarding the necessity and efficacy of preoperative vascular embolization have not been established yet. CASE PRESENTATION: This report aimed to assess the necessity and usefulness of preoperative vascular embolization in TEES for GTT by comparing the surgical findings of TEES without preoperative vascular embolization (Case 1) and TEES with preoperative vascular embolization (Case 2). Compared to Case 1, Case 2 included less bleeding and a more convenient procedure. However, no significant difference was observed. CONCLUSIONS: For GTT confined to the middle ear cavity (Glasscock-Jackson Grade II or less), when performed by a proficient otolaryngologist, TEES alone is sufficient without preoperative vascular embolization.

Prospective Study of Nonsurgical Auricular Correction According to Timing of Treatment.

BACKGROUND AND PURPOSE: Many studies recommend nonsurgical auricular correction during the early postnatal period, when cartilage plasticity is high; however, many patients are not eligible for the procedure. This study compared different timings of nonsurgical auricular correction to investigate benefit after the optimal period for correction. METHODS: In this prospective study, 53 ears from 35 patients with congenital auricular anomaly were assigned to two groups according to age at correction: the "early-group" with correction within 2 weeks of birth and "late-group" with correction 8 weeks after birth. Aesthetic outcomes, caregiver satisfaction, detachment rates and mean device-wearing periods, were compared. RESULTS: Thirty-one ears from 20 patients comprised the early-group, and 18 ears from 12 patients comprised the late-group. Mean time to treatment after birth was 9.09 days in the early-group and 134.7 days in the late-group. In the early-group, detachment occurred in 4/31 ears (12.9%), and in the late-group, detachment occurred in 12/18 ears (66.7%), which was statistically significant (p<0.01). The average period of applying devices was 4.7 ± 1.2 weeks in the early-group and 8.5 ± 4.1 weeks in the late-group, with a significantly longer treatment time in the late-group (p=0.001). The early-group had 87.1% "good" results vs. 55.6% in the late-group, with a statistically significant difference. CONCLUSIONS: The correction period was shorter, detachment rate was lower, and treatment outcome was better in the early-group. However, successful correction was also present in the late-group, showing that the patients who have passed the optimum correction period should proceed after counselling.

Differences in the metabolomic profile of the human palatine tonsil between pediatrics and adults.

Palatine tonsils (PT) are B cell-predominant lymphoid organs that provide primary immune responses to airborne and dietary pathogens. Numerous histopathological and immunological studies have been conducted on PT, yet no investigations have been conducted on its metabolic profile. We performed high-resolution magic angle spinning nuclear magnetic resonance spectroscopy-based metabolic profiling in 35 pediatric and 28 adult human palatine tonsillar tissue samples. A total of 36 metabolites were identified, and the levels of 10 metabolites were significantly different depending on age. Among them, partial correlation analysis shows that glucose levels increased with age, whereas glycine, phosphocholine, phosphoethanolamine, and ascorbate levels decreased with age. We confirmed the decrease in immunometabolic activity in adults through metabolomic analysis, which had been anticipated from previous histological and immunological studies on the PT. These results improve our understanding of metabolic changes in the PT with aging and serve as a basis for future tonsil-related metabolomic studies.

Hearing recovery prediction and prognostic factors of idiopathic sudden sensorineural hearing loss: a retrospective analysis with a deep neural network model.

OBJECTIVE: Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) is an otologic emergency, and an early prediction of prognosis may facilitate proper treatment. Therefore, we investigated the prognostic factors for predicting the recovery in patients with ISSHL treated with combined treatment method using machine learning models. METHODS: We retrospectively reviewed the medical records of 298 patients with ISSHL at a tertiary medical institution between January 2015 and September 2020. Fifty-two variables were analyzed to predict hearing recovery. Recovery was defined using Siegel's criteria, and the patients were categorized into recovery and non-recovery groups. Recovery was predicted by various machine learning models. In addition, the prognostic factors were analyzed using the difference in the loss function. RESULTS: There were significant differences in variables including age, hypertension, previous hearing loss, ear fullness, duration of hospital admission, initial hearing level of the affected and unaffected ears, and post-treatment hearing level between recovery and non-recovery groups. The deep neural network model showed the highest predictive performance (accuracy, 88.81%; area under the receiver operating characteristic curve, 0.9448). In addition, initial hearing level of affected and non-affected ear, post-treatment (2-weeks) hearing level of affected ear were significant factors for predicting the prognosis. CONCLUSION: The deep neural network model showed the highest predictive performance for recovery in patients with ISSHL. Some factors with prognostic value were identified. Further studies using a larger patient population are warranted. LEVEL OF EVIDENCE: Level 4.

Effects of Particulate Matter Exposure on the Eustachian Tube and Middle Ear Mucosa of Rats.

OBJECTIVES: Particulate matter (PM) is a risk factor for various diseases. Recent studies have established an association between otitis media (OM) and PM exposure. To confirm this relationship, we developed a novel exposure model designed to control the concentration of PM, and we observed the effects of PM exposure on the Eustachian tube (ET) and middle ear mucosa of rats. METHODS: Forty healthy, 10-week-old, male Sprague-Dawley rats were divided into 3-day, 7-day, 14-day exposure, and control groups (each, n=10). The rats were exposed to incense smoke as the PM source for 3 hours per day. After exposure, bilateral ETs and mastoid bullae were harvested, and histopathological findings were compared using microscopy and transmission electron microscopy (TEM). The expression levels of interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor (VEGF) in the middle ear mucosa of each group were compared using real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS: In the ET mucosa of the exposure group, the goblet cell count significantly increased after PM exposure (P=0.032). In the middle ear mucosa, subepithelial space thickening, increased angio-capillary tissue, and inflammatory cell infiltration were observed. Moreover, the thickness of the middle ear mucosa in the exposure groups increased compared to the control group (P<0.01). The TEM findings showed PM particles on the surface of the ET and middle ear mucosa, and RT-PCR revealed that messenger RNA (mRNA) expression of IL-1ß significantly increased in the 3-day and 7-day exposure groups compared to the control group (P=0.035). VEGF expression significantly increased in the 7-day exposure group compared to the control and 3-day exposure groups (P<0.01). CONCLUSION: The ET and middle ear mucosa of rats showed histopathologic changes after acute exposure to PM that directly reached the ET and middle ear mucosa. Therefore, acute exposure to PM may play a role in the development of OM.

E2F regulation of the Phosphoglycerate kinase gene is functionally important in Drosophila development.

The canonical role of the transcription factor E2F is to control the expression of cell cycle genes by binding to the E2F sites in their promoters. However, the list of putative E2F target genes is extensive and includes many metabolic genes, yet the significance of E2F in controlling the expression of these genes remains largely unknown. Here, we used the CRISPR/Cas9 technology to introduce point mutations in the E2F sites upstream of five endogenous metabolic genes in Drosophila melanogaster. We found that the impact of these mutations on both the recruitment of E2F and the expression of the target genes varied, with the glycolytic gene, Phosphoglycerate kinase (Pgk), being mostly affected. The loss of E2F regulation on the Pgk gene led to a decrease in glycolytic flux, tricarboxylic acid cycle intermediates levels, adenosine triphosphate (ATP) content, and an abnormal mitochondrial morphology. Remarkably, chromatin accessibility was significantly reduced at multiple genomic regions in PgkΔE2F mutants. These regions contained hundreds of genes, including metabolic genes that were downregulated in PgkΔE2F mutants. Moreover, PgkΔE2F animals had shortened life span and exhibited defects in high-energy consuming organs, such as ovaries and muscles. Collectively, our results illustrate how the pleiotropic effects on metabolism, gene expression, and development in the PgkΔE2F animals underscore the importance of E2F regulation on a single E2F target, Pgk.

Transcanal endoscopic myringoplasty with butterfly dermal allograft.

OBJECTIVE: Tympanic membrane perforation (TMP) is a common cause of visits to the otolaryngology clinic. For decades, various surgical methods and various grafts have been used to treat TMP. This study aimed to compare the efficacy of butterfly dermal allograft (BDA) and fat myringoplasty for the treatment of TMP. STUDY DESIGN: A retrospective case-control study. SETTING: Tertiary referral center. METHODS: We retrospectively analyzed 40 patients who underwent BDA (n = 20) and fat myringoplasty (n = 20) for TMP performed by a single surgeon between January 2019 and December 2021. The hearing outcomes, graft success rate, complications, operation time, and hospital stay were recorded and compared between the two groups. Hearing outcomes were determined by pure-tone audiometry. RESULTS: There was no significant difference between the BDA and fat groups regarding demographic characteristics. There was no significant difference in the pre and postoperative air conduction and bone conduction thresholds, or air-bone gap values between the two groups. A significant audiologic improvement was observed in both groups (p < 0.05), but there was no significant difference in the degree of hearing gain between the two groups. In terms of recurrence of tympanic membrane perforation, postoperative otorrhea, and discomfort symptoms; however, there was no significant difference between the groups (p > 0.05). The operation time and hospital stay were shorter in the BDA group than in the fat group (p < 0.05). CONCLUSION: BDA myringoplasty is as safe and medically efficacious as fat myringoplasty and shortens the operation time and hospital stay.

c-Jun N-terminal kinase 1 (JNK1) phosphorylates OTX2 transcription factor that regulates early retinal development.

BACKGROUND: The transcription factor orthodenticle homeobox 2 (OTX2) has critical functions in brain and eye development, and its mutations in humans are related to retinal diseases, such as ocular coloboma and microphthalmia. However, the regulatory mechanisms of OTX2 are poorly identified. OBJECTIVE: The identification of JNK1 as an OTX2 regulatory protein through the protein interaction and phosphorylation. METHODS: To identify the binding partner of OTX2, we performed co-immunoprecipitation and detected with a pooled antibody that targeted effective kinases. The protein interaction between JNK1 and OTX2 was identified with the co-immunoprecipitation and immunocytochemistry. In vivo and in vitro kinase assay of JNK1 was performed to detect the phosphorylation of OTX2 by JNK1. RESULTS: JNK1 directly interacted with OTX2 through the transactivation domain at the c-terminal region. The protein-protein interaction and co-localization between JNK1 and OTX2 were further validated in the developing P0 mouse retina. In addition, we confirmed that the inactivation of JNK1 K55N mutant significantly reduced the JNK1-mediated phosphorylation of OTX2 by performing an immune complex protein kinase assay. CONCLUSION: c-Jun N-terminal kinase 1 (JNK1) phosphorylates OTX2 transcription factor through the protein-protein interaction.

The Optimized Protocol of Hyperbaric Oxygen Therapy For Sudden Sensorineural Hearing Loss.

OBJECTIVE: This study aimed to determine the optimal protocol of hyperbaric oxygen therapy (HBOT) according to various treatment settings for sudden sensorineural hearing loss (SSNHL). METHODS: A 112 patients with SSNHL were enrolled in this prospective study. All patients were treated with systemic steroid therapy, intratympanic steroid therapy, and HBOT. According to the pressure and duration of HBOT (10 sessions in total), the patients were divided into three groups: group 1, 2.5 atmospheres absolute (ATA) for 1 h; group 2, 2.5 ATA for 2 h; and group 3, 1.5 ATA for 1 h. The pure-tone average (PTA), word discrimination score (WDS), and mean gain were compared. RESULTS: A total of 105 patients completed the 3-month follow-up, and 6 patients were excluded. Differences among groups were found in PTA, WDS, and mean gain. In the post-hoc analysis, group 3 had significantly lower WDS and mean gain than groups 1 and 2; however, group 2 showed no significant differences from group 1. The proportion of patients with hearing recovery after treatment was significantly higher in group 1 (57.6%) and group 2 (58.8%) than in group 3 (31.3%). CONCLUSIONS: When HBOT (10 sessions) was combined with corticosteroids as the initial therapy for SSNHL, a higher pressure (1.5 ATA vs. 2.5 ATA) provided better treatment results; however, increasing the duration (1 h vs. 2 h) under 2.5 ATA did not result in a significant difference. Therefore, HBOT for SSNHL may be performed at 2.5 ATA for 1 h in 10 sessions. Laryngoscope, 133:383-388, 2023.

Hearing recovery prediction and prognostic factors of idiopathic sudden sensorineural hearing loss: a retrospective analysis with a deep neural network model

Abstract Objective Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) is an otologic emergency, and an early prediction of prognosis may facilitate proper treatment. Therefore, we investigated the prognostic factors for predicting the recovery in patients with ISSHL treated with combined treatment method using machine learning models. Methods We retrospectively reviewed the medical records of 298 patients with ISSHL at a tertiary medical institution between January 2015 and September 2020. Fifty-two variables were analyzed to predict hearing recovery. Recovery was defined using Siegel's criteria, and the patients were categorized into recovery and non-recovery groups. Recovery was predicted by various machine learning models. In addition, the prognostic factors were analyzed using the difference in the loss function. Results There were significant differences in variables including age, hypertension, previous hearing loss, ear fullness, duration of hospital admission, initial hearing level of the affected and unaffected ears, and post-treatment hearing level between recovery and non-recovery groups. The deep neural network model showed the highest predictive performance (accuracy, 88.81%; area under the receiver operating characteristic curve, 0.9448). In addition, initial hearing level of affected and non-affected ear, post-treatment (2-weeks) hearing level of affected ear were significant factors for predicting the prognosis. Conclusion The deep neural network model showed the highest predictive performance for recovery in patients with ISSHL. Some factors with prognostic value were identified. Further studies using a larger patient population are warranted. Level of evidence: Level 4.

CRISPR/Cas9-Mediated Editing of AGAMOUS-like Genes Results in a Late-Bolting Phenotype in Chinese Cabbage (Brassica rapa ssp. pekinensis).

Due to the sudden change in temperature in spring, Chinese cabbage, a leafy vegetable cultivated for consumption, loses its commercial value due to the onset of bolting­the phenomenon of switching from vegetative to reproductive growth. In this study, we applied clustered regularly interspaced short palindromic repeats/(CRISPR)-associated system 9 (CRISPR/Cas9) technology to analyze AGAMOUS-like genes. We performed functional analysis of AGL19 and AGL24 genes related to bolting and flowering using CRISPR/Cas9-mediated Chinese cabbage transformation. Single-guide RNA (sgRNA) sequences were created with a low off-targeting probability to construct gene-editing vectors. Agrobacterium-mediated transformation was conducted, and tentative E0 AGL-edited lines were analyzed using molecular biotechnological methods. Two AGL19-edited lines with nucleotide sequence mutations in the target sequence of the AGL19 genes and four AGL24-edited lines with nucleotide sequence mutations in the target sequence of the AGL24 genes showed particularly late bolting compared to the inbred line 'CT001.' Generational progression using bud pollination obtained T-DNA-free E1 AGL-edited lines, which also showed late bolting. The loss of function of the AGL protein was caused by the occurrence of an indel mutation in the AGL19 and AGL24 genes, which results in an early stop codon. Furthermore, frameshift mutations led to structural changes and the introduction of an early stop codon in the AGL19 and AGL24 proteins. Our results indicate that CRISPR/Cas9-mediated editing of AGAMOUS-like genes results in a late-bolting phenotype and that CRISPR/Cas9 is a useful technology for analyzing gene function in Chinese cabbage (Brassica rapa ssp. pekinensis).

Treatment results for congenital cholesteatoma using transcanal endoscopic ear surgery.

PURPOSE: Transcanal endoscopic ear surgery for congenital cholesteatoma provides a smaller incision and better visibility than conventional surgical microscope ear surgery. We aimed to evaluate the treatment results of transcanal endoscopic ear surgery in ameliorating the recurrence and post-operative complications of pediatric congenital cholesteatoma. MATERIALS AND METHODS: A retrospective chart review was conducted on patients with congenital cholesteatoma who underwent transcanal endoscopic ear surgery at a tertiary referral medical center from January 2012 to December 2020. We categorized the patients into two groups according to the presence of remnant cholesteatoma and compared their characteristics. RESULTS: This study included 46 patients (32 males and 14 females; 46 ears). The mean age was 3.0 ± 2.6 (1-17) years. Congenital cholesteatoma was predominantly located in the anterior-superior quadrant (63.0 %), and ossicular involvement was confirmed in six cases. The mean cholesteatoma size identified by temporal bone computed tomography was 3.9 ± 2.0 (1.2-13) mm. Seven cases had remnant cholesteatoma lesions (15.2 %); four improved after revision surgery, and three were followed up without immediate further intervention. Postoperative complications (e.g., tympanic membrane perforation, retraction) were observed in 10 cases. Comparative evaluations of various characteristics after categorizing the participants into residual and non-residual lesion groups revealed no significant differences. CONCLUSIONS: Consequently, transcanal endoscopic ear surgery can be considered an effective and safe operation for treating congenital cholesteatoma in the pediatric population with no serious side effects. Further large-scale research with hearing test results should be conducted meticulously as a follow-up to this study.

A new role for ammonia in tumorigenesis?

Tumor-supporting roles of ammonia have gained greater appreciation in recent years and normally focus on ammonia's role as a nitrogen source. Recently in Nature Metabolism,Cheng et al. (2022) demonstrate a novel, non-nitrogen, metabolism-related role of ammonia as a key activator for lipogenesis by facilitating SREBP-1 activation.

Role of heat shock protein 60 in primed and naïve states of human pluripotent stem cells.

Human pluripotent stem cells (hPSCs) exist in at least two distinct states in mammals: naïve pluripotency that represents several molecular characteristics in pre-implantation epiblast and primed pluripotency that corresponds to cells poised for differentiation in post-implantation epiblast. To identify and characterize the surface molecules that are necessary for the maintenance of naïve hPSCs, we generated a panel of murine monoclonal antibodies (MAbs) specific to the naïve state of hPSCs. Flow cytometry showed that N1-A4, one of the MAbs, bound to naïve hPSCs but not to primed hPSCs. Cell surface biotinylation and immunoprecipitation analysis identified that N1-A4 recognized heat shock protein 60 (HSP60) expressed on the surface of naïve hPSCs. Quantitative polymerase chain reaction (qPCR) analysis showed that HSP60 expression was rapidly downregulated during the embryoid body (EB) differentiation of primed hPSCs. HSP60 knockdown led to a decrease in the expression of pluripotency genes in primed hPSCs. HSP60 depletion also led to a decrease in the expression of pluripotency genes and representative naïve-state-specific genes in naïve hPSCs. Taken together, the results suggest that HSP60 is downregulated during differentiation of hPSCs and is required for the maintenance of pluripotency genes in both primed and naïve hPSCs, suggesting that HSP60 is a regulator of hPSC pluripotency and differentiation.

Using Transcriptome Analysis to Explore Gray Mold Resistance-Related Genes in Onion (Alliumcepa L.).

Gray mold disease caused by Botrytis in onions (Allium cepa L.) during growth and storage negatively affects their yield and quality. Exploring the genes related to gray mold resistance in onion and their application to the breeding of resistant onion lines will support effective and ecological control methods of the disease. Here, the genetic relationship of 54 onion lines based on random amplified polymorphic DNA (RAPD) and in vitro-cultured onion lines infected with gray mold were used for screening resistance and susceptibility traits. Two genetically related onion lines were selected, one with a resistant and one with a susceptible phenotype. In vitro gray mold infection was repeated with these two lines, and leaf samples were collected for gene expression studies in time series. Transcript sequences obtained by RNA sequencing were subjected to DEG analysis, variant analysis, and KEGG mapping. Among the KEGG pathways, 'α-linoleic acid metabolism' was selected because the comparison of the time series expression pattern of Jasmonate resistant 1 (JAR1), Coronatine-insensitive protein 1 (COI 1), and transcription factor MYC2 (MYC2) genes between the resistant and susceptible lines revealed its significant relationship with gray-mold-resistant phenotypes. Expression pattern and SNP of the selected genes were verified by quantitative real-time PCR and high-resolution melting (HRM) analysis, respectively. The results of this study will be useful for the development of molecular marker and finally breeding of gray-mold-resistant onions.

Effects of cigarette smoke on Haemophilus influenzae-induced otitis media in a rat model.

Exposure to cigarette smoke (CS) is a factor that could delay or worsen the recovery of otitis media (OM) by causing inflammatory swelling of the Eustachian tube (ET). However, despite the suggested relationship, little is known about the association between OM and CS. Therefore, we aimed to evaluate the effects of CS on the development, progression, and recovery of OM, as well as the histological and molecular changes caused by CS exposure, by using a rat model of OM infected with non-typeable Haemophilus influenzae (NTHi). Eighty Sprague-Dawley rats with normal middle ears (MEs) were divided into four groups (n = 20 rats/group): control, CS, OM, and CS + OM. The CS and CS + OM groups were exposed to CS for 2 weeks. The inflammatory reaction to NTHi was more intense and lasted longer in the CS + OM group than in the other groups. Goblet cell proliferation and mucus secretion in the ET were more significant in the CS and CS + OM groups than in the other groups. These findings suggested that because CS directly affects the ET and ME mucosa, bacterial OM can become more severe and may resolve more slowly in the presence of CS exposure rather than in its absence.