Dnmt1 is required for the development of auditory organs via cell cycle arrest and Fgf signalling.

OBJECTIVES: To explore the role of DNA methyltransferase 1 (DNMT1) in the development of auditory system using zebrafish as experimental model. METHODS: Morpholino oligonucleotide was used to induce Dnmt1 deficiency. RNA sequencing, in situ hybridization (ISH), whole genomic bisulfide sequencing (WGBS) and immunostaining were used to investigate the morphologic alterations and mechanisms. RESULTS: We found that downregulation of Dnmt1 induced decreased number of neuromasts and repressed cell proliferation of primordium in the developing posterior lateral line system of zebrafish. The ISH data uncovered that Fgf signalling pathway was inhibited and the expression of chemokine members cxcr4b, cxcr7b and cxcl12a were interfered, while lef1 expression was increased after inhibiting Dnmt1. Additionally, Dnmt1 downregulation led to malformed otoliths and deformed semicircular canals, and hair cell differentiation in utricle and saccule was inhibited severely. The in situ staining of otic placode markers pax2/5 and fgf 3/8/10 was decreased when Dnmt1 downregulated. The WGBS analysis demonstrated that the global methylation status was markedly downregulated, and cell cycle genes were among those most differently expressed between Dnmt1 morphants and the controls. Further ISH analysis confirmed the findings by RNA-seq and WGBS assay that cdkn1a and tp53 were both upregulated after knockdown of Dnmt1. CONCLUSION: Our results revealed that Dnmt1 is essential for the development of zebrafish auditory organ through regulating cell cycle genes together with Wnt and Fgf signalling pathways.

Silencing MR-1 Protects against Myocardial Injury Induced by Chronic Intermittent Hypoxia by Targeting Nrf2 through Antioxidant Stress and Anti-Inflammation Pathways.

BACKGROUND: Patients with obstructive sleep apnea hypopnea syndrome (OSAHS) often have cardiac insufficiency mainly due to hypoxia/reperfusion injury caused by chronic intermittent hypoxia (CIH). Inflammation and oxidative stress are involved in the cardiovascular events of OSAHS patients. Studies have found that myofibrillation regulator-1 (MR-1) participates in the pathological process of OSAHS-induced myocardial injury, but the specific mechanism is still unclear. METHODS: We used a CIH-induced rat model to simulate the process of OSAHS disease. Indices of myocardial injury, inflammation, and oxidative stress were detected using quantitative PCR and enzyme-linked immunosorbent assay (ELISA). After administration of adenoassociated viral vector (AAV) encoding silencing RNA against MR-1, we examined expression of the classic antioxidant stress pathway protein NF-E2-related factor 2 (Nrf2) using western blotting. RESULTS: We found that levels of serum inflammatory factors tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, and IL-8 were increased, and we further observed disturbance of the oxidative stress system, in which the content of reactive oxygen species (ROS), superoxide dismutase (SOD), reduced glutathione (GSH), and malondialdehyde (MDA) was enhanced in CIH-induced rats. Subsequently, we detected that expression of Nrf2 and heme oxygenase-1 (HO-1) was slightly increased, while the expression of Kelch-like ECH-associated protein 1 (Keap-1) was significantly increased in the CIH model. Interestingly, after administration of silencing MR-1 AAV, the elevated levels of inflammatory factors were reduced, and the disordered oxidative stress system was corrected. Additionally, the expression of Nrf2 and HO-1 was distinctly increased, but the high expression of Keap-1 was decreased. CONCLUSIONS: Our research results demonstrate that silencing MR-1 rescued the myocardium the injury from inflammatory and oxidative stress in CIH-induced rats by administration of the Nrf2 signaling pathway.

Preliminary comparison of the efficacy of several surgical treatments based on maxillomandibular advancement procedures in adult patients with obstructive sleep apnoea: a systematic review and network meta-analysis.

PURPOSE: To evaluate the efficacy of eight different surgical treatments based on maxillomandibular advancement (MMA), which has emerged in recent years, for adult obstructive sleep apnoea (OSA) patients. METHODS: The literature was searched from January 2010 to May 2020 for studies of adult OSA patients with different types of MMA procedures to perform a network meta-analysis. The outcomes were changes in the apnoea-hypopnoea index (AHI), the lowest pulse oxygen saturation (SpO2 min) and the Epworth Sleepiness Scale (ESS). Treatment hierarchy was summarized according to the rank charts. RESULTS: Eight studies were included and encompassed a total of 227 adult patients diagnosed with OSA. Among them, 225 patients underwent combined surgery or simple MMA surgery, including modified maxillomandibular advancement (MMMA),counterclockwise maxillomandibular advancement (CMMA), drug-induced sleep endoscopy and maxillomandibular advancement (MMA + DISE), transoral robotic surgery and maxillomandibular advancement (MMA + TORS), uvulopalatopharyngoplasty (UPPP), maxillomandibular advancement and uvulopalatopharyngoplasty (MMA + UPPP), uvulopalatopharyngoplasty with uvula preservation and maxillomandibular advancement (MMA + HUPPP); MMA consisting of Le Fort I osteotomy and bilateral inverted-L osteotomy (ILOs), genioplasty and iliac bone grafting; and MMA consisting of Le Fort I osteotomy, bilateral sagittal split ramus osteotomies and genioplasty. The results showed that the most effective surgical treatment is MMA + HUPPP [- 56.79 (WMD); 95% confidence interval (CI): - 113.02 to - 3.33] (P < 0.00001), which was far superior to other approaches. CONCLUSION: MMA combined with HUPPP had the highest efficacy. The MMA consisted of Le Fort I osteotomy, bilateral sagittal split ramus osteotomies and genioplasty; CMMA and MMA + TORS are likely also great choices.

Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L.) Assisted by Corynebacterium variabile.

The accumulation of a considerable quantity of gibberellin fermentation residue (GFR) during gibberellic acid A3 (GA3) production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL) and microbes (Corynebacterium variabile) to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26 °C. A total of 371 g housefly larvae meal and 2,064 g digested residue were bio-converted from 3,500 g raw GFR mixture contaning1, 400 g rice straw in the unit of (calculated) dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.