Dual role of lipids for genome stability and pluripotency facilitates full potency of mouse embryonic stem cells

While Mek1/2 and Gsk3β inhibition ("2i") supports the maintenance of murine embryonic stem cells (ESCs) in a homogenous naïve state, prolonged culture in 2i results in aneuploidy and DNA hypomethylation that impairs developmental potential. Additionally, 2i fails to support derivation and culture of fully potent female ESCs. Here we find that mouse ESCs cultured in 2i/LIF supplemented with lipid-rich albumin (AlbuMAX) undergo pluripotency transition yet maintain genomic stability and full potency over long-term culture. Mechanistically, lipids in AlbuMAX impact intracellular metabolism including nucleotide biosynthesis, lipid biogenesis, and TCA cycle intermediates, with enhanced expression of DNMT3s that prevent DNA hypomethylation. Lipids induce a formative-like pluripotent state through direct stimulation of Erk2 phosphorylation, which also alleviates X chromosome loss in female ESCs. Importantly, both male and female "all-ESC" mice can be generated from de novo derived ESCs using AlbuMAX-based media. Our findings underscore the importance of lipids to pluripotency and link nutrient cues to genome integrity in early development.

Clinical analysis of three cases of infratentorial dural arteriovenous fistula / 中华神经科杂志

Objective:To improve awareness about infratentorial dural arteriovenous fistula (DAVF).Methods:Three cases of DAVF in the First Affiliated Hospital of Soochow University from September 2017 to September 2019 were retrospectively analyzed in terms of clinical features, cerebrospinal fluid (CSF) analysis, brain imaging and treatment, and followed up through telephone call.Results:Case 1: A 43-year-old woman, in chronic but acute aggravated course, presented with weakness of both lower limbs and urination and defecation dysfunction. Brain magnetic resonance imaging (MRI) revealed abnormal signal in medulla. CSF analysis demonstrated aquaporin-4 antibodies positive. Misdiagnosed as neuromyelitis optica spectrum disorders, the treatment was poor. Then digital subtraction angiography (DSA) showed DAVF at the left infratentorial area, and endovascular treatment was operated. Relapse was not observed in two-year follow up. Case 2: A 57-year-old woman, in chronic progressive course, mainly manifested as memory loss, but progressed with dysphagia, fever, coma. Treatment as “central nervous infection” was poor. Then DSA showed DAVF at the bilateral transverse-sigmoid sinus area, and endovascular treatment was operated with embolized partial fistulas. The patient died from lung infection within two months. Case 3: A 52-year-old man, in subacute course, was treated in the Gastroenterology Department with clinical manifestion of stubborn nausea and vomiting. Brain MRI revealed abnormal signal in medulla, with prominent vessel flow voids nearby. Then DSA showed DAVF at the craniocervical junction, and endovascular treatment was operated. Relapse was not observed in six-month follow up.Conclusions:DAVF has a variety of clinical manifestations, and infratentorial DAVF can manifest as acute neurological dysfunction involving the brain stem, cerebellum, spinal cord, which may be easily misdiagnosed. When brain MRI showed intracranial abnormal signal, the possibility of DAVF should be considered. DSA remains the gold standard to diagnose DAVF. Endovascular embolization is the main treatment of infratentorial DAVF at present. Prognosis depends on clinical presentation and fistula classification.