MSC-derived exosomes protect auditory hair cells from neomycin-induced damage via autophagy regulation.

BACKGROUND: Sensorineural hearing loss (SNHL) poses a major threat to both physical and mental health; however, there is still a lack of effective drugs to treat the disease. Recently, novel biological therapies, such as mesenchymal stem cells (MSCs) and their products, namely, exosomes, are showing promising therapeutic potential due to their low immunogenicity, few ethical concerns, and easy accessibility. Nevertheless, the precise mechanisms underlying the therapeutic effects of MSC-derived exosomes remain unclear. RESULTS: Exosomes derived from MSCs reduced hearing and hair cell loss caused by neomycin-induced damage in models in vivo and in vitro. In addition, MSC-derived exosomes modulated autophagy in hair cells to exert a protective effect. Mechanistically, exogenously administered exosomes were internalized by hair cells and subsequently upregulated endocytic gene expression and endosome formation, ultimately leading to autophagy activation. This increased autophagic activity promoted cell survival, decreased the mitochondrial oxidative stress level and the apoptosis rate in hair cells, and ameliorated neomycin-induced ototoxicity. CONCLUSIONS: In summary, our findings reveal the otoprotective capacity of exogenous exosome-mediated autophagy activation in hair cells in an endocytosis-dependent manner, suggesting possibilities for deafness treatment.

Norepinephrine protects against cochlear outer hair cell damage and noise-induced hearing loss via α2A-adrenergic receptor.

BACKGROUND: The cochlear sympathetic system plays a key role in auditory function and susceptibility to noise-induced hearing loss (NIHL). The formation of reactive oxygen species (ROS) is a well-documented process in NIHL. In this study, we aimed at investigating the effects of a superior cervical ganglionectomy (SCGx) on NIHL in Sprague-Dawley rats. METHODS: We explored the effects of unilateral and bilateral Superior Cervical Ganglion (SCG) ablation in the eight-ten weeks old Sprague-Dawley rats of both sexes on NIHL. Auditory function was evaluated by auditory brainstem response (ABR) testing and Distortion product otoacoustic emissions (DPOAEs). Outer hair cells (OHCs) counts and the expression of α2A-adrenergic receptor (AR) in the rat cochlea using immunofluorescence analysis. Cells culture and treatment, CCK-8 assay, Flow cytometry staining and analysis, and western blotting were to explore the mechanisms of SCG fibers may have a protective role in NIHL. RESULTS: We found that neither bilateral nor unilateral SCGx protected the cochlea against noise exposure. In HEI-OC1 cells, H2O2-induced oxidative damage and cell death were inhibited by the application of norepinephrine (NE). NE may prevent ROS-induced oxidative stress in OHCs and NIHL through the α2A-AR. CONCLUSION: These results demonstrated that sympathetic innervation mildly affected cochlear susceptibility to acoustic trauma by reducing oxidative damage in OHCs through the α2A-AR. NE may be a potential therapeutic strategy for NIHL prevention.

MSC-derived exosomes protect auditory hair cells from neomycin-induced damage via autophagy regulation

Background Sensorineural hearing loss (SNHL) poses a major threat to both physical and mental health; however, there is still a lack of effective drugs to treat the disease. Recently, novel biological therapies, such as mesenchymal stem cells (MSCs) and their products, namely, exosomes, are showing promising therapeutic potential due to their low immunogenicity, few ethical concerns, and easy accessibility. Nevertheless, the precise mechanisms underlying the therapeutic effects of MSC-derived exosomes remain unclear. Results Exosomes derived from MSCs reduced hearing and hair cell loss caused by neomycin-induced damage in models in vivo and in vitro. In addition, MSC-derived exosomes modulated autophagy in hair cells to exert a protective effect. Mechanistically, exogenously administered exosomes were internalized by hair cells and subsequently upregulated endocytic gene expression and endosome formation, ultimately leading to autophagy activation. This increased autophagic activity promoted cell survival, decreased the mitochondrial oxidative stress level and the apoptosis rate in hair cells, and ameliorated neomycin-induced ototoxicity. Conclusions In summary, our findings reveal the otoprotective capacity of exogenous exosome-mediated autophagy activation in hair cells in an endocytosis-dependent manner, suggesting possibilities for deafness treatment.

PTEN inhibitor bisperoxovanadium protects against noise-induced hearing loss.

Studies have shown that phosphatase and tensin homolog deleted on chromosome ten (PTEN) participates in the regulation of cochlear hair cell survival. Bisperoxovanadium protects against neurodegeneration by inhibiting PTEN expression. However, whether bisperoxovanadium can protect against noise-induced hearing loss and the underlying mechanism remains unclear. In this study, we established a mouse model of noise-induced hearing loss by exposure to 105 dB sound for 2 hours. We found that PTEN expression was increased in the organ of Corti, including outer hair cells, inner hair cells, and lateral wall tissues. Intraperitoneal administration of bisperoxovanadium decreased the auditory threshold and the loss of cochlear hair cells and inner hair cell ribbons. In addition, noise exposure decreased p-PI3K and p-Akt levels. Bisperoxovanadium preconditioning or PTEN knockdown upregulated the activity of PI3K-Akt. Bisperoxovanadium also prevented H2O2-induced hair cell death by reducing mitochondrial reactive oxygen species generation in cochlear explants. These findings suggest that bisperoxovanadium reduces noise-induced hearing injury and reduces cochlear hair cell loss.

TNN is first linked to auditory neuropathy.

Autosomal recessive nonsyndromic auditory neuropathy is attributed to a genetic etiology. We identified a compound heterozygous missense variant, c.G736A (p.G246S) and c.C2954T (p.T985 M) in TNN of affected patients in a pedigree via candidate gene screening and exome sequencing. To determine the genetic etiology of deafness in the pedigree with a heterozygous missense variant in the gene TNN encoding tenascin-W associated with autosomal recessive nonsyndromic auditory neuropathy, the cochlear expression of tenascin-W was evaluated at mRNA and protein levels in mice, and Tnn knock out mice were generated and utilized to study the function of Tnn in the auditory system. Immunofluorescence stainings showed that tenascin-W was mainly expressed in the somatic cytoplasm of spiral ganglion neurons of mice. Homozygous Tnn knockout was lethal in mice, whereas Tnn heterozygous mice showed decreases in spiral ganglion neuron density and progressive hearing loss. We demonstrate that tenascin-W is expressed in the murine cochleae and is essential for the development of spiral ganglion neurons. An abnormal expression of tenascin-W can influence the development and function of SGNs and affect the function of the auditory system.

A forskolin-loaded nanodelivery system prevents noise-induced hearing loss.

Hearing loss is the most common sensory disorder worldwide and may result from age, drugs, or exposure to excessive noise. Crossing the blood-labyrinth barrier to achieve targeted drug delivery to the inner ear is key to the treatment of hearing loss. We designed a nanoparticle (NP)-based system for targeted drug delivery of forskolin (FSK) to the inner ear, driven by the prestin-targeting peptide LS19 ("ligand-receptor type interaction"). In vivo experiments in developing zebrafish embryos (4-96 h past fertilization) and mice confirmed that LS19-FSK specifically targeted and accumulated in zebrafish lateral line neuromasts and mouse outer hair cells (OHCs). LS19 peptide modification enabled LS19-FSK-NPs to rapidly target OHCs with high specificity. Furthermore, the multifunctional LS19-FSK-NPs were successfully delivered to the OHCs via the round window membrane route and exhibited slow-release properties. The sustained release and intracellular accumulation of FSK inhibited apoptosis of OHCs. Compared with LS19-NPs and FSK-NPs, LS19-FSK-NPs provided significantly stronger protection against noise-induced hearing damage, based on auditory brainstem responses at 4, 8, 16, and 32 kHz. Thus, our specially designed targeted nano-delivery system may serve as a basis for future clinical applications and treatment platforms and has the potential to significantly improve the treatment results of many inner ear diseases.

Hypoxia-induced RBBP7 promotes esophagus cancer progression by inducing CDK4 expression.

Hypoxia-induced epigenetic regulation calls for more effective therapeutic targets for esophageal cancer. We used GEPIA and UALCAN databases to screen survival-related and cancer stage-associated genes. Eca109 and KYSE450 esophageal cancer cell lines were cultured under normoxia, hypoxia, or CoCl-induced hypoxia conditions, which were further transfected with plasmids expressing RB binding protein 7 (RBBP7), hypoxia-inducible factor 1 (HIF1)-α, or RBBP7 shRNA. Colony formation and MTT assays were used to detect cell proliferation. Tumor sphere formation and stemness marker detection were applied to assess cell stemness. RT-PCR and western blot analysis were used to detect the relative mRNA level and protein expression, respectively. Luciferase assay was utilized to detect the direct interaction between HIF1α and RBBP7. Up-regulated RBBP7 was identified as one of the most prominent survival-related genes, which is negatively correlated with the overall survival (OS), disease recurrence-free survival (DFS), and tumor stages. Hypoxia-induced HIF1α up-regulates RBBP7 expression, which promotes esophagus cancer cell viability, proliferation, and stemness with increased cyclin-dependent kinase 4 (CDK4) expression. Luciferase reporter assay verified that HIF1α transcriptionally regulates the expression of RBBP7. We conclude that hypoxia induces high expression of RBBP7 which is at least partially mediated by HIF1α, up-regulates the expression of downstream CDK4, and thereby promotes tumor progression in esophageal cancer cells.

Motivators and barriers to social participation in two Chinese long-term care institutions: A focus-group study.

This study used focus group interviews with 40 older Chinese long-term care residents to explore their motivators and barriers to social participation in institutional settings informed by their lived experience. Using inductive thematic analysis, we found that motivators include pursuit of healthy ageing (better physical and mental health) and pursuit of meaningful ageing (sense of achievement and being useful, increased connectedness and realization of dreams from earlier life). The reported barriers illuminate structural components such as life-course experiences, long-term care-related barriers and Chinese policy-related barriers. The discussion highlights the importance of understanding the multidimensionality of motivators and barriers to social participation. To promote healthy ageing among institutionalized residents, staff and policy makers are recommended to initiate and support meaningful activities for residents. Residents' individual dreams and accumulated life-course disadvantages experienced long before admission to long-term care should also be considered when devising effective interventions to increase residents' level of social participation.

Modified subxiphoid approach for surgical resection of a retrosternal goiter.

Backgrounds: Unilateral Video-Assisted Thorascopic Surgery (VATS) is a traditional minimally invasive transthoracic approach for the surgical resection of a subxiphoid goiter. Recently, the subxiphoid approach was recommended for an anterior mediastinal mass. This study aims to investigate the feasibility and efficacy of a modified subxiphoid VATS for the resection of a retrosternal goiter as an alternative transthoracic approach. Methods: We retrospectively collected all patients who underwent subxiphoid VATS for the resection of a retrosternal goiter from June 2017 to June 2021 in the Zhongshan Hospital or the Zhongshan Hospital Xiamen branch. Ten patients were found. Patient characteristics, perioperative data, and surgical information were collected and further analyzed. Results: In our study, all 10 patients underwent a thoracoscopic subxiphoid resection of a retrosternal goiter. The mean age was 49.4 years, and all were female. The majority of patients (70%) were asymptomatic. All patients were assessed by CT imaging before surgery. The mean postoperative hospital stay was 4.9 days. The drainage tube was removed 3 days after operation, and the average drainage volume was 73.1 ml. Postoperative pain was mild, with an average pain grade of 2.4 (measured on a scale from 0 to 10, with lower scores indicating less pain). There were no conversions or perioperative complications in these 10 patients. Conclusions: Most retrosternal goiters can be completely resected through the modified subxiphoid approach after an adequate preoperative evaluation and careful intraoperative management. This thoracoscopic subxiphoid approach is feasible and safe for retrosternal goiter resection.

MiR-519d-3p enhances the sensitivity of non-small-cell lung cancer to tyrosine kinase inhibitors.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. Tyrosine kinase inhibitors (TKIs) are currently the most effective chemotherapy for NSCLC. However, most cancer patients develop TKI resistance at tumor relapse stage. We firstly measured the expression change of miR-519d-3p in TKI resistance NSCLC cells. We then ectopically expressed miR-519-3p in TKI resistant cells to study its functional impact on cell proliferation, migration, invasion and cell sensitivity to gefitinib. The downstream target of miR-519-3p was identified by bioinformatics and validated in luciferase reporter assay and western blotting analysis. We also studied the reversing effect of the candidate target in NSCLC cells expressing miR-519d-3p. Lastly, we compared the miR-519d-3p level in NSCLC patients with good or poor response to gefitinib. miR-519d-3p level was downregulated in TKI resistant NSCLC cells. The restoration of miR-519d-3p in these NSCLC cells inhibited cell proliferation, invasion and migration; enhanced cell sensitivity to gefitinib. EPAS1 was identified and validated as downstream target of miR-519d-3p. Co-expressing EPAS1 antagonized the inhibitory effect of miR-519d-3p on NSCLC cells. MiR-519d-3p was downregulated in NSCLC patients with poor response to gefitinib. Targeting miR-519d-3p/EPAS1 axis may provide alternative treatment for TKI-resistant NSCLC.

'It's like a double-edged sword': understanding Confucianism's role in activity participation among first-generation older Chinese migrants in the Netherlands and Belgium.

While activity participation in later life has attracted considerable attention from policymakers and scholars, indoor and outdoor engagement among older Chinese migrants in Europe is understudied. Using in-depth interviews with 21 older Chinese migrants in the Netherlands and seven in Belgium, this study is among the first to explore older Chinese migrants' activity participation experiences from the perspective of Confucianism, the cornerstone of Chinese culture. More specifically, the impact of four acknowledged principles of Confucianism are considered: hierarchical relationships, family system, benevolence and emphasis on education. The findings show that, like a double-edged sword, these four principles have positive and negative effects on older Chinese migrants' activity participation. Hierarchical relationships promote formal organisational participation, yet concurrently dividing the Chinese community into smaller subgroups and endangering solidarity within the community. With regard to family system, which emphasizes intergenerational responsibility and obligation, older Confucianist migrants prioritise taking care of their grandchildren, resulting in less time to participate in outdoor activities. Benevolence, the third principle of Confucianism, restrains older Chinese migrants from political participation while encouraging them to attend community meetings where food is shared. Lastly, emphasis on education, of which self-cultivation is an important aspect, helps older Chinese migrants overcome feelings of loneliness and makes them prefer self-learning activity above formal learning settings (e.g. language learning) organised by the government. The article ends with policy recommendations on how to increase older Chinese migrants' outdoor activities.

Identifying Lung Cancer Patients Suitable for Segmentectomy: A Brief Review.

Background: In 1995, a clinical randomized controlled study (RCT) conducted by the Lung Cancer Study Group (LCSG) pointed out that the lobectomy was the gold standard for treating early lung cancer. However, with the development of technology, the results of several retrospective studies have shown that the efficacy of pulmonary segmentectomy is equivalent to that of lobectomy. Currently, it is still controversial whether segmental resection or lobectomy should be performed for early lung cancer. Thus, we aim to summarize the indications of segmentectomy. Methods: To conduct the review, previous researches involving indications of segmentectomy were collected from the literature using Pubmed. These articles were published and accepted in English in the medical literature from 2013 to 2020. We have focused on segmentectomy and its indications. Results: A total of 176 articles were retrieved from the Pubmed database, of which 31 articles included indications for segmentectomy. We summarized the relevant content, and the potential and prospect of segmentectomy for the treatment of lung cancer were emphasized. Conclusions: These findings have a number of important implications for future practice. Pulmonary segmentectomy is a very vital surgical procedure for select patients with lung cancer, which provides a novel approach for the treatment of lung cancer and the survival of lung cancer patients.

A study of three-dimensional reconstruction and printing models in two cases of soft tissue sarcoma of the thigh.

PURPOSE: The aim of our study was to demonstrate the value of three-dimensional (3D) reconstruction and three-dimensional printing (3DP) models in two cases of soft tissue sarcoma (STS) of the thigh. MATERIALS AND METHODS: Two patients with STS were recruited and underwent enhanced CT and MRI scans. Then, the 3D models were reconstructed and printed using the obtained data, and five experts were invited to assess the segmentation quality. In addition, 34 junior, intermediate and senior general surgeons were recruited to demonstrate the value of 3D models in preoperative planning and invited five surgeons to complete the assessment of 3D models-assisted intraoperative navigation. Finally, 32 interns were enrolled to explore the significance of 3D models in medical education. RESULTS: All experts agree with the accuracy of the 3D models. The application of 3D models in preoperative planning improved the understanding of general surgeons (P = 0.000, P = 0.000, P = 0.000). After the planning tools were exchanged between the two groups, senior surgeons in group A showed more significant improvements in performance than junior and intermediate surgeons in group A (P = 0.001, P = 0.006). Surgeons unanimously agree on the value of 3D models in intraoperative navigation. When applied for the education of medical interns, these models could enhance their understanding of pathologic anatomies (P = 0.036). CONCLUSION: In two operations for STS of the thigh with complex adjacencies, our study demonstrates that 3D models are of great value for preoperative planning, intraoperative navigation and medical education. More importantly, these models were more helpful to senior general surgeons.

EPAS1 promotes peritoneal carcinomatosis of non-small-cell lung cancer by enhancing mesothelial-mesenchymal transition.

BACKGROUND: Non-small-cell lung cancer (NSCLC) is a major cause of cancer-related death globally. Endothelial PAS domain-containing protein 1 (EPAS1) is a homolog of the hypoxia-inducible factor 1α and has been reported to confer tyrosine kinase inhibitor (TKI) resistance in NSCLC, but its role in peritoneal carcinomatosis of NSCLC is unknown. METHODS: PC14HM, a high metastatic potential subline of NSCLC cell line PC14, was derived. Stable shRNA knockdown of EPAS1 was then established in PC14HM cells and subjected to assessment regarding the effects on proliferation and viability, xenograft tumor growth, metastatic potential, mesothelial-mesenchymal transition (MMT)-related characteristics and peritoneal carcinomatosis in a mouse model. RESULTS: EPAS1 expression was elevated in PC14HM cells. Knockdown of EPAS1 inhibited the proliferation and viability of PC14HM cells in vitro and suppressed tumorigenesis in vivo. In addition, the metastatic features and in vitro productions of MMT-inducing factors in PC14HM cells was also associated with EPAS1. More importantly, knockdown of EPAS1 drastically suppressed peritoneal carcinomatosis of PC14HM cells in vivo. CONCLUSION: EPAS1 promotes peritoneal carcinomatosis of NSCLC through enhancement of MMT and could therefore serve as a prognostic marker or a therapeutic target in treating NSCLC, particularly in patients with peritoneal carcinomatosis.

Analysis of the variation pattern in left upper division veins and establishment of simplified vein models for anatomical segmentectomy.

BACKGROUND: Three-dimensional computed tomography bronchography and angiography (3D-CTBA) is a powerful tool to analyze pulmonary anatomy. We used 3D-CTBA to analyze variations of the pulmonary veins of the left upper division (LUD) and created a simplified LUD vein model. METHODS: Between January 2019 and October 2019, 124 patients with left-sided pulmonary lesions were admitted and underwent 3D-CTBA prior to surgery. We reviewed the anatomical variations of the LUD veins in these patients using 3D-CTBA images and classified them according to their position in relation to the bronchus. To facilitate this process, the same nomenclature as that used to describe the veins of the right upper lobe (RUL) is used for the LUD. RESULTS: The pattern of LUD veins could be classified into three forms: an anterior + central form, an anterior form and a central form. For the central form, V 1+2 a, V 1+2 b, V 1+2 c and V 1+2 d drained into V. cent. For the anterior form, V 1+2 d drained into V. ant. The anterior + central form could be further classified into three subtypes (V abc, V ab and V a). CONCLUSIONS: This is the first report to categorize the pattern of veins in the LUD. This may facilitate the creation of simplified models for use in pre-operative planning for segmentectomy.

Social Participation in Older Adults after Relocation to Long-Term Care Institutions in China: A Qualitative Study.

This study used focus group interviews with older Chinese long-term care residents (N = 40), to explore their perspectives and experiences of social participation in long-term care institutions. Based on previously established taxonomy of different activity levels, we found that their social participation centered on level 3 (involvement with others), level 4 (task-oriented activities), and level 5 activities (helping others). Participants indicated that their social participation had changed after relocation. Thematic analysis revealed three main themes: increased spare time, increased presence of peers, and new participation opportunities with lost old hobbies. Focusing on the positive changes after relocation and promoting meaningful activities of different levels may benefit long-term care residents.

miR-182 prevented ototoxic deafness induced by co-administration of kanamycin and furosemide in rats.

Ototoxic drugs may induce auditory sensory hair cell loss and permanent deafness; however, there is still no effective treatments or prevention strategies for this side effect. A recent study found that microRNA182 (miR-182) protected cochlear hair cells from ototoxic drug-induced apoptosis in vitro. However, it remains unclear whether miR-182 can protect drug-induced deafness in vivo. In this study, we overexpressed cochlear miR-182 in Sprague-Dawley rats by trans-round window niche delivery of miR-182 mimics. The rats subsequently received intraperitoneal injections of kanamycin and furosemide to induce acute cochlear outer hair cell death and permanent deafness. Auditory brainstem response tests showed that miR-182 attenuated permanent threshold shifts. Consistent with this result, miR-182 reduced the loss of outer hair cells and missing stereocilia. miR-182 treatment also increased the level of phosphoinositide-3 kinase regulatory subunit p85α in the outer hair cells after co-administration of kanamycin and furosemide. Our findings suggest that miR-182 has powerful protective potential against ototoxic drug-induced acute auditory sensory hair cell loss and permanent deafness.

Outer hair cells isolation from postnatal Sprague-Dawley rats.

Outer hair cells (OHCs) damage is a general phenomenon in clinical disorders such as noise-induced hearing loss and drug-induced hearing loss. In order to elucidate the mechanism underlying these disorders, OHCs - its diseased region needs to be deeply investigated. However, OHCs array on the basilar membrane which contains massive cells with different types. Therefore, to isolate OHCs from this huge population is significant for revealing its pathological and molecular changes during disease processing. In the present study, we tried to isolate OHCs from the commonly used animal model -Sprague-Dawley (SD) rats. By separating outer hair cells from SD rats with different day ages, we found that 9 days after birth was a suitable time for the separation of the OHCs. At this time, the number of OHCs isolated from rats was large, and the cell morphology was typical of cylindrical shape. OHCs isolated using this method are histologically suitable and quantitatively adequate for molecular biological and electrophysiological analyses.