DMXL2 Is Required for Endocytosis and Recycling of Synaptic Vesicles in Auditory Hair Cells.

Ribbon synapses of inner hair cells (IHCs) are uniquely designed for ultrafast and indefatigable neurotransmission of the sound. The molecular machinery ensuring the efficient, compensatory recycling of the synaptic vesicles (SVs), however, remains elusive. This study showed that hair cell knock-out of murine Dmxl2, whose human homolog is responsible for nonsyndromic sensorineural hearing loss DFNA71, resulted in auditory synaptopathy by impairing synaptic endocytosis and recycling. The mutant mice in the C57BL/6J background of either sex had mild hearing loss with severely diminished wave I amplitude of the auditory brainstem response. Membrane capacitance measurements of the IHCs revealed deficiency in sustained synaptic exocytosis and endocytic membrane retrieval. Consistent with the electrophysiological findings, 3D electron microscopy reconstruction showed reduced reserve pool of SVs and endocytic compartments, while the membrane-proximal and ribbon-associated vesicles remain intact. Our results propose an important role of DMXL2 in hair cell endocytosis and recycling of the SVs.

SIRT5 exacerbates eosinophilic chronic rhinosinusitis by promoting polarization of M2 macrophage.

BACKGROUND: Previous studies implied that local M2 polarization of macrophage promoted mucosal edema and exacerbated TH2 type inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP). However, the specific pathogenic role of M2 macrophages and the intrinsic regulators in the development of CRS remains elusive. OBJECTIVE: We sought to investigate the regulatory role of SIRT5 in the polarization of M2 macrophages and its potential contribution to the development of CRSwNP. METHODS: Real-time reverse transcription-quantitative PCR and Western blot analyses were performed to examine the expression levels of SIRT5 and markers of M2 macrophages in sinonasal mucosa samples obtained from both CRS and control groups. Wild-type and Sirt5-knockout mice were used to establish a nasal polyp model with TH2 inflammation and to investigate the effects of SIRT5 in macrophage on disease development. Furthermore, in vitro experiments were conducted to elucidate the regulatory role of SIRT5 in polarization of M2 macrophages. RESULTS: Clinical investigations showed that SIRT5 was highly expressed and positively correlated with M2 macrophage markers in eosinophilic polyps. The expression of SIRT5 in M2 macrophages was found to contribute to the development of the disease, which was impaired in Sirt5-deficient mice. Mechanistically, SIRT5 was shown to enhance the alternative polarization of macrophages by promoting glutaminolysis. CONCLUSIONS: SIRT5 plays a crucial role in promoting the development of CRSwNP by supporting alternative polarization of macrophages, thus providing a potential target for CRSwNP interventions.

Gut microbiota and chronic rhinosinusitis: a two-sample Mendelian randomization study.

BACKGROUND: The nasal cavity and gut are interconnected, both housing a rich natural microbiome. Gut microbiota may interact with nasal microbiota and contribute to the development of chronic rhinosinusitis (CRS). However, the specific role of gut microbiota in CRS has not been fully investigated. Therefore, we conducted a two-sample Mendelian randomization study to reveal the potential genetic causal effect of gut microbiota on CRS. METHODS: We performed a two-sample Mendelian Randomization (MR) analysis using aggregated data from genome-wide association studies (GWAS) on gut microbiota and CRS. The primary method used to assess the causal relationship between gut microbiota and CRS was the inverse variance weighting (IVW) method. In addition, sensitivity analyses were conducted to evaluate the robustness of the MR results, including heterogeneity, pleiotropy, and leave-one-out tests. RESULTS: Genetically predicted twelve gut microbiota, including class Coriobacteriia, class Methanobacteria, family Coriobacteriaceae, family Methanobacteriaceae, family Pasteurellaceae, genus Haemophilus, genus Ruminococcus torques group, genus Subdoligranulum, order Coriobacteriales, order Methanobacteriales, order Pasteurellales, and phylum Proteobacteria, demonstrated a potential inhibitory effect on CRS risk (P < 0.05). In addition, four gut microbiota, including family Streptococcaceae, genus Clostridium innocuum group, genus Oscillospira, and genus Ruminococcaceae NK4A214 group, exhibited a causal role in increasing CRS risk (P < 0.05). Sensitivity analyses showed no evidence of heterogeneity or pleiotropy (P > 0.05). CONCLUSIONS: This study reveals the causal relationship between specific gut microbiota and CRS, which provides a new direction and theoretical foundation for the future development of interventions and prevention and treatment strategies for CRS.

Infratemporal Fossa Schwannoma Surgery via a Combined Prelacrimal Recess, Caldwell-Luc, and Distal Intraoral Approach.

BACKGROUND: The deep location of infratemporal fossa (ITF) combined with the abundant vascular plexus in it increased the difficulty of removing the mass in ITF through endoscope surgery approach. However, under appropriate circumstances, the excision of ITF tumors through a combined prelacrimal recess, Caldwell-Luc, and distal intraoral approach can be safely performed with minimal impact on the surrounding tissues. CASE PRESENTATION: The Department of Neurology received a 69-year-old male patient who had been experiencing headache, dizziness, and numbness from the mastoid region of his left ear to the corner of his mouth for a duration of 22 days. Cranial magnetic resonance imaging revealed the presence of a tumor located in the ITF. Following transfer to our department, surgical intervention was performed using a combined approach involving the prelacrimal recess, the anterior wall of maxillary sinus, and lateral ITF to successfully remove the tumor. Postoperative pathologic examination confirmed schwannoma as its nature. The patient was discharged in excellent condition without any functional impairment. CONCLUSIONS: On the basis of this case, the authors believe that this combined approach can offer a distinct endoscopic perspective and adequate surgical workspace, which is crucial for tumor removal while preserving the integrity of surrounding normal tissues. Moreover, the utilization of multiple small incisions has minimal impact on postoperative recovery.

Analysis of Diagnosis and Treatment Strategies for Parapharyngeal Space Tumors With Follicular Dendritic Sarcoma.

BACKGROUND: Parapharyngeal space tumor is a tumor that occurs in the parapharyngeal space. Parapharyngeal space tumors are uncommon, accounting for about 0.5% of head and neck tumors. Eighty percent of them are benign and 20% are malignant. The pathologic types of tumors are varied, mainly neurogenic tumors and salivary gland tumors. Follicular dendritic sarcomas are much rarer, with an inert biological behavior and a low-grade malignant sarcoma. Clinicians face difficulties in the management of this lesion. Therefore, a comprehensive analysis of the management of this disease is necessary. CASE PRESENTATIONS: In May 2023, a 22-year-old male presented with pharyngeal discomfort, dysphagia, and sleep apnea. The patient underwent MRI which showed a rounded hypodense shadow with a size of 3.2×2.1×4.5 cm in the left lateral pharyngeal wall and a mass located in the posterior aspect of the left submandibular gland. After preliminary diagnosis of left parapharyngeal space tumor and left neck mass, the clinician performed transoral endoscopy-assisted resection of the left parapharyngeal space tumor and transcervical resection of the left cervical mass. The patient has been followed up without recurrence. CONCLUSIONS: This case provided a reference for the diagnosis and management of parapharyngeal space tumors. In particular, new insights into the diagnosis and management of a rare pathologic type were presented, which had the potential to improve the overall understanding of this disease.

Analysis of Diagnosis and Treatment Strategies for Primary Juvenile Psammomatoid Ossifying Fibroma Complicated With Primary Aneurysmal Bone Cyst.

BACKGROUND: Juvenile Psammomatoid Ossifying Fibroma (JPOF) is a type of noncancerous bone tumor that usually affects adolescents in the craniomaxillofacial area. Clinical manifestations are usually symptoms caused by the tumor's invasive compression of surrounding tissues. Aneurysmal Bone Cyst (ABC) is also a benign bone tumor, and it typically occurs in long bones and the spine. Only 2% to 3% of cases occur in the head and neck. Due to the rarity of this combination of clinical cases, clinicians face difficulties in comprehensively understanding this complex lesion. Therefore, a comprehensive review of the clinical manifestations and characteristic imaging findings is necessary for surgeons. CASE PRESENTATIONS: On April 6, 2019, a 13-year-old boy presented with left maxillofacial bulge and pain for 1 month. Magnetic resonance imaging of the paranasal sinuses showed an irregular hive-like mass signal in the left maxillary sinus, and cystic changes with fluid levels were seen in the lesion. After the initial diagnosis of JPOF with primary ABC, we decided to perform a facial mid-facial resection of maxillary sinus tumor to remove the tumor tissue. Finally, after 3 recurrences and 4 operations, there was no tumor recurrence for 20 months after the last operation, and the patient was still under continuous follow-up. CONCLUSIONS: This case provided a reference for the diagnosis and treatment of JPOF combined with ABC. In particular, a new understanding of the association between the two diseases and the management of recurrence were proposed, which had the potential to improve clinical understanding of this complicated condition.

Profiling of the chemical space on the phenyl group of substituted benzothiazole RIPK3 inhibitors.

Necroptosis is confirmed as a precisely programmed cell death that is activated in caspase-deficient conditions. Receptor-interacting protein kinase 1 (RIPK1), RIPK3 and mixed-lineage kinase domain-like pseudokinase (MLKL) are the key regulators involved in the signaling pathway. However, accumulating evidence suggests that RIPK1 also works in apoptosis and inflammation pathways independent of necroptosis. Differently, RIPK3 signals necroptosis independent of RIPK1. Thus, identification of specific RIPK3 inhibitors is of great importance for the drug development associated with necroptosis. The benzothiazole carboxamide is a privileged scaffold as RIPK3 inhibitors developed by our group recently. In this study, we work on the phenyl group in-between of benzothiazole and carboxamide to profile the chemical space. Finally, a chlorinated derivative XY-1-127 was found to specifically inhibit necroptosis rather than apoptosis with an EC50 value of 676.8 nM and target RIPK3 with a Kd of 420 nM rather than RIPK1 (Kd = 4300 nM). It was also confirmed to block the formation of necrosome by inhibiting RIPK3 phosphorylation at 1 µM in necroptosis cells. This work discovers the chemical space insights on the phenyl group of the substituted benzothiazole RIPK3 inhibitors and provides a new lead compound for further development.

Identification and analysis of lipid metabolism-related genes in allergic rhinitis.

BACKGROUND: Studies have shown that the lipid metabolism mediator leukotriene and prostaglandins are associated with the pathogenesis of allergic rhinitis (AR). The aim of this study was to identify key lipid metabolism-related genes (LMRGs) related to the diagnosis and treatment of AR. MATERIALS AND METHODS: AR-related expression datasets (GSE75011, GSE46171) were downloaded through the Gene Expression Omnibus (GEO) database. First, weighted gene co-expression network analysis (WGCNA) was used to get AR-related genes (ARRGs). Next, between control and AR groups in GSE75011, differentially expressed genes (DEGs) were screened, and DEGs were intersected with LMRGs to obtain lipid metabolism-related differentially expressed genes (LMR DEGs). Protein-protein interaction (PPI) networks were constructed for these LMR DEGs. Hub genes were then identified through stress, radiality, closeness and edge percolated component (EPC) analysis and intersected with the ARRGs to obtain candidate genes. Biomarkers with diagnostic value were screened via receiver operating characteristic (ROC) curves. Differential immune cells screened between control and AR groups were then assessed for correlation with the diagnostic genes, and clinical correlation analysis and enrichment analysis were performed. Finally, real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was made on blood samples from control and AR patients to validate these identified diagnostic genes. RESULTS: 73 LMR DEGs were obtained, which were involved in biological processes such as metabolism of lipids and lipid biosynthetic processes. 66 ARRGs and 22 hub genes were intersected to obtain four candidate genes. Three diagnostic genes (LPCAT1, SGPP1, SMARCD3) with diagnostic value were screened according to the AUC > 0.7, with markedly variant between control and AR groups. In addition, two immune cells, regulatory T cells (Treg) and T follicular helper cells (TFH), were marked variations between control and AR groups, and SMARCD3 was significantly associated with TFH. Moreover, SMARCD3 was relevant to immune-related pathways, and correlated significantly with clinical characteristics (age and sex). Finally, RT-qPCR results indicated that changes in the expression of LPCAT1 and SMARCD3 between control and AR groups were consistent with the GSE75011 and GSE46171. CONCLUSION: LPCAT1, SGPP1 and SMARCD3 might be used as biomarkers for AR.

Multidisciplinary Team in Severe Infectious Complications Caused by Pharyngeal Foreign Body.

BACKGROUND: Pharyngeal foreign body is not only a common emergency in people's daily life, but also a common simple disease in otorhinolaryngology. However, the disease is easy to be ignored due to its common occurrence, which may lead to a series of serious complications including sepsis and local abscess. CASE PRESENTATION: In this case, a patient with sepsis, piriform fistula, deep neck abscess, and mediastinal abscess caused by a fishbone was reported. After reviewing the international literature on severe infectious complications caused by foreign bodies in pharynx, the authors emphasize the important role of multidisciplinary team in dealing with complex complications. RESULT: The whole process of patient from onset to recovery was summarized in a timeline. During hospitalization, the value of leukocyte counts and C-reactive protein in routine blood test was record dynamically. The electronic laryngoscopy, neck computed tomography and chest computed tomography were used to judge treatment efficacy. After about 2 months of hospitalization, the patient was recovered without sequelae. No adverse reactions were found during the follow-up. CONCLUSION: The incorrect method of removing foreign body after mis-swallowing may develop serious complications. Therefore, It is important to strengthen medical preaching for general population of correct treatments after foreign body ingestion. In addition, the case reminds clinicians to pay more attention to patients' medical history and details of all medical examinations, which may provide significant clues for making the correct diagnosis and treatment quickly.

A Review of Microsurgical Resection of Recurrent Laryngeal Neurilemmoma Under Nerve Monitoring.

BACKGROUND: Laryngeal neurilemmoma, especially recurrent laryngeal neurilemmoma, is a rare neural sheath tumor in head and neck. The most common symptom of laryngeal neurilemmoma is hoarseness or dysphonia, followed by dysphagia, dyspnea, and foreign body sensation. At present, surgical resection is the most effective treatment for this kind of tumor, thus making how to remove it become the most concerned problem of surgeons. CASE PRESENTATION: On February 18, 2021, a 64-year-old male presented to our clinic with recurrent sore throat and intermittent hoarseness for 3 years. The results of electronic laryngoscope and magnetic resonance imaging showed a 25×10×21 mm well-defined tumor in the left pyriform sinus without laryngeal cartilage destruction and enlarged lymph nodes. After the initial diagnosis of recurrent laryngeal neurilemmoma, to preserve the continuity of recurrent laryngeal nerve as much as possible, the authors determine to perform anatomical resection of recurrent laryngeal neurilemmoma with operating microscope under the monitoring of recurrent laryngeal nerve function. Finally, the patient recovered completely from hoarseness during postoperative follow-up. CONCLUSION: A complete diagnosis and treatment process of recurrent laryngeal neurilemmoma was presented by the case. Particularly, it shows the application of recurrent laryngeal nerve monitoring in the operation helps to protect the continuity of the recurrent laryngeal nerve, which lays a anatomical bases for the follow-up nerve repair.