http://hdl.handle.net/20.500.11897/497322 State Key Laboratory of Membrane Biology Mon, 08 Jul 2024 12:50:36 GMT 2024-07-08T12:50:36Z http://hdl.handle.net/20.500.11897/712692 Title: Interleukin-33 ameliorates perioperative neurocognitive disorders by modulating microglial state Authors: Yang, Di; Sun, Yi; Lin, Dandan; Li, Sijie; Zhang, Yan; Wu, Anshi; Wei, Changwei Abstract: Perioperative neurocognitive disorders (PND) are cognitive dysfunctions that usually occur in elderly patients after anesthesia and surgery. Microglial overactivation is a key underlying mechanism. Interleukin-33 (IL-33) is a member of the IL-1 family that orchestrates microglial function. In the present study, we explored how IL-33, which regulates microglia, contributes to cognitive improvement in a male mouse model of PND. An exploratory laparotomy was performed to establish a PND model. The expression levels of IL-33 and its receptor ST2 were evaluated using Western blot. IL-33/ST2 secretion, microglial density, morphology, phagocytosis of synapse, and proliferation, and dystrophic microglia were assessed using immunofluorescence. Synaptic plasticity was measured using Golgi staining and long-term potentiation. The Morris water maze and open field test were used to evaluate cognitive function and anxiety. Hippocampal expression of IL-33 and ST2 were elevated on postoperative day 3. We confirmed that IL-33 was secreted by astrocytes and neurons, whereas ST2 mainly colocalized with microglia. IL-33 treatment induced microgliosis after anesthesia and surgery. These microglia had larger soma sizes and shorter and fragmented branches. Compared to the Surgery group, IL-33 treatment reduced the synaptic phagocytosis of microglia and increased microglial proliferation and dystrophic microglia. IL-33 treatment also reversed the impaired synaptic plasticity and cognitive function caused by anesthesia and surgery. In conclusion, these results indicate that IL-33 plays a key role in regulating microglial state and synaptic phagocytosis in a PND mouse model. IL-33 treatment has a therapeutic potential for improving cognitive dysfunction in PND. Thu, 01 Aug 2024 00:00:00 GMT http://hdl.handle.net/20.500.11897/712692 2024-08-01T00:00:00Z http://hdl.handle.net/20.500.11897/712616 Title: Apolipoprotein B Secretion Assay from Primary Hepatocytes Authors: Wang, Yawei; Li, Xin; Huang, Runze; Chen, Xiao-Wei; Wang, Xiao Abstract: Apolipoprotein B (APOB) is the primary structural protein of atherogenic lipoproteins, which drive atherogenesis and thereby lead to deadly cardiovascular diseases (CVDs). Plasma levels of APOB-containing lipoproteins are tightly modulated by LDL receptor-mediated endocytic trafficking and cargo receptor-initiated exocytic route; the latter is much less well understood. This protocol aims to present an uncomplicated yet effective method for detecting APOB/lipoprotein secretion. We perform primary mouse hepatocyte isolation and culture coupled with wellestablished techniques such as immunoblotting for highly sensitive, specific, and semi -quantitative analysis of the lipoprotein secretion process. Its inherent simplicity facilitates ease of operation, rendering it a valuable tool widely utilized to explore the intricate landscape of cellular lipid metabolism and unravel the mechanistic complexities underlying lipoprotein -related diseases. Wed, 01 May 2024 00:00:00 GMT http://hdl.handle.net/20.500.11897/712616 2024-05-01T00:00:00Z http://hdl.handle.net/20.500.11897/712599 Title: Spatiotemporal Organization of Prefrontal Norepinephrine In fl uences Neuronal Activity Authors: Glaeser-Khan, Samira; Savalia, Neil K.; Cressy, Jianna; Feng, Jiesi; Li, Yulong; Kwan, Alex C.; Kaye, Alfred P. Abstract: Norepinephrine (NE), a neuromodulator released by locus ceruleus (LC) neurons throughout the cortex, influences arousal and learning through extrasynaptic vesicle exocytosis. While NE within cortical regions has been viewed as a homogenous field, recent studies have demonstrated heterogeneous axonal dynamics and advances in GPCR-based fluorescent sensors permit direct observation of the local dynamics of NE at cellular scale. To investigate how the spatiotemporal dynamics of NE release in the prefrontal cortex (PFC) affect neuronal firing, we employed in vivo two -photon imaging of layer 2/3 of the PFC in order to observe fine -scale neuronal calcium and NE dynamics concurrently. In this proof of principle study, we found that local and global NE fields can decouple from one another, providing a substrate for local NE spatiotemporal activity patterns. Optic flow analysis revealed putative release and reuptake events which can occur at the same location, albeit at different times, indicating the potential to create a heterogeneous NE field. Utilizing generalized linear models, we demonstrated that cellular Ca 2+ fluctuations are influenced by both the local and global NE field. However, during periods of local/global NE field decoupling, the local field drives cell firing dynamics rather than the global field. These findings underscore the significance of localized, phasic NE fluctuations for structuring cell firing, which may provide local neuromodulatory control of cortical activity. Wed, 01 May 2024 00:00:00 GMT http://hdl.handle.net/20.500.11897/712599 2024-05-01T00:00:00Z http://hdl.handle.net/20.500.11897/712218 Title: An octopamine-specific GRAB sensor reveals a monoamine relay circuitry that boosts aversive learning Authors: Lv, Mingyue; Cai, Ruyi; Zhang, Renzimo; Xia, Xiju; Li, Xuelin; Wang, Yipan; Wang, Huan; Zeng, Jianzhi; Xue, Yifei; Mao, Lanqun; Li, Yulong Abstract: Octopamine (OA), analogous to norepinephrine in vertebrates, is an essential monoamine neurotransmitter in invertebrates that plays a significant role in various biological functions, including olfactory associative learning. However, the spatial and temporal dynamics of OA in vivo remain poorly understood due to limitations associated with the currently available methods used to detect it. To overcome these limitations, we developed a genetically encoded GPCR activation-based (GRAB) OA sensor called GRABOA1.0. This sensor is highly selective for OA and exhibits a robust and rapid increase in fluorescence in response to extracellular OA. Using GRABOA1.0, we monitored OA release in the Drosophila mushroom body (MB), the fly's learning center, and found that OA is released in response to both odor and shock stimuli in an aversive learning model. This OA release requires acetylcholine (ACh) released from Kenyon cells, signaling via nicotinic ACh receptors. Finally, we discovered that OA amplifies aversive learning behavior by augmenting dopamine-mediated punishment signals via Oct beta 1R in dopaminergic neurons, leading to alterations in synaptic plasticity within the MB. Thus, our new GRABOA1.0 sensor can be used to monitor OA release in real time under physiological conditions, providing valuable insights into the cellular and circuit mechanisms that underlie OA signaling. Mon, 01 Apr 2024 00:00:00 GMT http://hdl.handle.net/20.500.11897/712218 2024-04-01T00:00:00Z