中文摘要：

小膠質細胞是大腦駐留的巨噬細胞，可以獲得不同的功能表型，這些表型得到了細胞代謝差異重編程的支持。這些適應包括糖酵解和線粒體代謝通量的重塑，可能會改變組織水平的能量底物可用性。這種現(xiàn)象可能與大腦高度相關，因為在大腦中，新陳代謝必須得到精確調節(jié)，以維持適當?shù)纳窠?jīng)元興奮性和突觸傳遞。然而，小膠質細胞可以影響神經(jīng)元能量代謝的直接證據(jù)一直缺乏。結合分子分析、電生理學、氧微傳感器記錄和數(shù)學建模，我們研究了神經(jīng)炎癥期間小膠質細胞介導的大腦能量紊亂。我們的結果表明，促炎小膠質細胞表現(xiàn)出增強的一氧化氮釋放和 CX3CR1 表達降低，短暫增加了組織乳酸/葡萄糖比率，這取決于小膠質細胞中的轉錄重編程，而不是神經(jīng)元中的轉錄重編程。在這種情況下，神經(jīng)網(wǎng)絡活動，如伽馬振蕩（30-70 Hz）可以通過線粒體中ATP的產生增加來推動，這反映在耗氧量增加上。在失調的炎癥期間，高能量需求和低葡萄糖可用性可能是神經(jīng)元代謝適應性的邊界條件，正如單神經(jīng)元能量學的動力學模型所揭示的那樣。總的來說，這些發(fā)現(xiàn)表明，在中度神經(jīng)炎癥期間，代謝靈活性可以保護神經(jīng)元網(wǎng)絡功能免受局部底物可用性的改變。。

英文摘要：

Microglia, brain-resident macrophages, can acquire distinct functional phenotypes, which are supported by differential reprogramming of cell metabolism. These adaptations include remodeling in glycolytic and mitochondrial metabolic fluxes, potentially altering energy substrate availability at the tissue level. This phenomenon may be highly relevant in the brain, where metabolism must be precisely regulated to maintain appropriate neuronal excitability and synaptic transmission. Direct evidence that microglia can impact on neuronal energy metabolism has been widely lacking, however. Combining molecular profiling, electrophysiology, oxygen microsensor recordings and mathematical modeling, we investigated microglia-mediated disturbances in brain energetics during neuroinflammation. Our results suggest that proinflammatory microglia showing enhanced nitric oxide release and decreased CX3CR1 expression transiently increase the tissue lactate/glucose ratio that depends on transcriptional reprogramming in microglia, not in neurons. In this condition, neuronal network activity such as gamma oscillations (30–70 Hz) can be fueled by increased ATP production in mitochondria, which is reflected by elevated oxygen consumption. During dysregulated inflammation, high energy demand and low glucose availability can be boundary conditions for neuronal metabolic fitness as revealed by kinetic modeling of single neuron energetics. Collectively, these findings indicate that metabolic flexibility protects neuronal network function against alterations in local substrate availability during moderate neuroinflammation.

論文信息：

論文題目：Metabolic flexibility ensures proper neuronal network function in moderate neuroinflammation

期刊名稱：Scientific Reports

時間期卷：volume 14, Article number: 14405 (2024) pages685–700 (2024)

在線時間：2024年6月22日

研究亮點：

代謝靈活性確保了炎癥期間神經(jīng)元網(wǎng)絡的正常功能。在體內平衡中，血液輸入葡萄糖的消耗和腦細胞平行產生乳酸，從乳酸/葡萄糖比值低的血管周圍空間到實質（該比率增加）產生溫和的能量底物梯度。在炎癥期間，小膠質細胞葡萄糖消耗和乳酸產生通過代謝重編程得到增強，這導致更高的乳酸/葡萄糖比率，加劇了血管周圍空間和腦實質之間的能量底物梯度。在這種情況下，神經(jīng)元網(wǎng)絡活動可能會通過平行增加耗氧量來保持。炎癥期間神經(jīng)元能量適應性的邊界是高能量需求伴隨著極低的葡萄糖可用性。在炎癥失調的生態(tài)位中可能會達到這些限制，其中反應性小膠質細胞的聚集可能發(fā)生在遠離毛細血管的區(qū)域。

材料方法：

氯膦酸鹽脂質體巨噬細胞清除劑Clodronateliposomes（liposoma，CP-005-005）加入培養(yǎng)基清除小膠質巨噬細胞，可以參考這篇文獻。腦切片體外培養(yǎng)，文獻濃度是100ug/ml。荷蘭liposoma巨噬細胞清除劑Clodronate Liposomes的濃度是5mg/ml。僅僅體外實驗才建議稀釋，用無菌PBS稀釋。