Silencing of METTL3 inhibits m6A methylation of NEK7 to suppress pyrolysis in an HT-22 cell-based model of intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) induces severe neurological damage, and its progression is driven by METTL3. This study aimed to investigate the role of METTL3 in ICH via in vitro experiments. For this purpose, HT-22 cells were treated with hemin to mimic ICH in vitro, followed by evaluating cell pyroptosis using flow cytometry, lactic dehydrogenase release analysis, enzyme-linked immunosorbent assay, and western blotting. Moreover, N6-methyl adenosine (m6A) methylation of NEK7 was assessed using methylated RNA immunoprecipitation, RNA immunoprecipitation, dual-luciferase reporter assay, and quantitative real-time polymerase chain reaction. Results indicated that knockdown of METTL3 inhibited hemin-induced pyroptosis and suppressed m6A methylation of NEK7 due to METTL3 downregulation, reducing NEK7 mRNA stability. The effects on METTL3-induced cell pyroptosis were abrogated by overexpressing NEK7, while IGF2BP2 increased NEK7 expression. Similarly, IGF2BP2 silence downregulated NEK7 expression mediated by METTL3. In conclusion, silencing of METTL3 inhibited hemin-induced HT-22 cell pyroptosis by suppressing m6A methylation of NEK7, which was recognized by IGF2BP2. These findings are envisaged to identify a novel therapeutic strategy for ICH.

Brain-Derived Neurotrophic Factor Inhibits the Wound-Healing and Cell Proliferative Ability of Human Airway Epithelial Cells in Asthmatic Children.

BACKGROUND Asthma is a chronic disease with high morbidity rates. Brain-derived neurotrophic factor (BDNF) has been proven to induce airway hyper-responsiveness, but the function of BDNF in the wound-healing process of asthmatic human airway epithelial cells (HAECs) remains unclear. This study investigated the effects of BDNF in asthmatic children with injured HAECs. MATERIAL AND METHODS HAECs were obtained from healthy children and asthmatic children through bronchoscopy, and then cultured in air-liquid (ALI) interface with or without BDNF. A mechanical injury model was established for the wound-healing assay. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was performed to measure BDNF mRNA expressions, while western blot assay was used for the measurement of BDNF and CCND1 protein expressions. Cell proliferation of impaired HAECs was assayed in a ³H-thymidine incorporation experiment. RESULTS The mRNA and protein levels of BDNF were overexpressed, and the wound-healing ability of HAECs decreased in asthma samples. Also, the cell proliferation of HAECs was suppressed in the asthmatic injury model and the injury-induced increase of CCND1 protein expressions was inhibited in asthma. Although mRNA and protein expressions of BDNF remained unchanging in healthy HAECs, there was an increase in impaired asthmatic HAECs. Upregulating BDNF led to a decrease in wound-healing ability of HAECs in both healthy children and children with asthma. Simultaneously, overexpressed BDNF reduced the CCND1 protein expressions in healthy HAECs, but had little impact on asthmatic HAECs. CONCLUSIONS Brain-derived neurotrophic factor (BDNF) inhibited wound-healing and cell proliferative ability of human airway epithelial cells (HAECs) in asthmatic children.

Cholangiocarcinoma accompanied by desmoid-type fibromatosis.

BACKGROUND: Cholangiocarcinoma complicated by intra-abdominal desmoid-type fibromatosis (DTF) is uncommon. There are no reports on patients with this type of fibromatosis, in which the pre-operative treatment (including diagnosis), surgical approach, post-operative pathologic reports, and prognosis are discussed. METHOD: The clinicopathological features of a 49-year-old man were retrospectively analyzed. RESULTS: Cholangiocarcinoma located in the inferior segment of the bile duct was considered pre-operatively on the basis of clinical findings. At the time of pancreaticoduodenectomy, the mesojejunum was stiff without nodules or a mass at a distance of approximately 80 cm from the ligament of Treitz. Complete excision of the entire lesion of the intestinal mesenteric contracture and its subsidiary was performed. Post-operative pathologic findings confirmed an adenocarcinoma located at the extremity of the common bile duct and infiltrating the full thickness of the common bile duct as well as the deep muscular layer of the duodenum. The contracted jejunal mesentery was shown to have DTF. The patient was alive with no evidence of recurrence after a follow-up of 6 months. CONCLUSIONS: The patient had a rare hereditary disease with intra-abdominal DTF, which manifests the characteristics of an aggressive growth pattern and a high rate of local recurrence; conservative therapy is recommended. Complete excision of the fibromatous lesion during pancreaticoduodenectomy may maximally decrease the risk of local recurrence.