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Updated: Jun 20, 2026
Characterization and Isolation of Mouse Primary Microglia by Density Gradient Centrifugation
Published on: February 16, 2018
Millepurpan from Astragali Radix binds condensin SMC2 to reverse microglial cell cycle arrest and metabolic
Yue Li1, Xue-Fei Yang2, Shui-Yuan Yang1
1State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
Abstract:
Microglia are key immune cells in the central nervous system, whose dysfunction contributes to neuroinflammation and neurological disorders. Astragali Radix (AR), the root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao, is known for neuroprotective effects, yet its active compounds remain underexplored. This study reports the first isolation of Millepurpan (MPP) from AR extract and reveals its potent anti-inflammatory effects in BV-2 microglial cells stimulated with lipopolysaccharide (LPS). Binding assays show MPP targets the ATPase head domain of structural maintenance of chromosomes 2 (SMC2), a condensin complex subunit, inducing steric hindrance that obstructs the ATP-binding pocket. LPS suppresses SMC2 nuclear translocation, causing p21-mediated G0/G1 arrest; MPP restores nuclear SMC2 and promotes G1/S transition. Seahorse metabolic analysis indicates MPP reverses LPS-induced glycolytic reprogramming, an effect abolished by Palbociclib co-treatment, highlighting cell cycle progression's role in metabolic regulation. In vivo, MPP crosses the blood-brain barrier, reduces microglial hyperactivation, and protects neurons in LPS-treated C57BL/6 mice. Immunofluorescence confirms MPP rescues nuclear SMC2 depleted by LPS, supporting its anti-neuroinflammatory action. Reanalysis of single-cell RNA sequencing datasets indicates dysregulation of SMC2 and downstream genes in Alzheimer's disease patients, suggesting SMC2 as a potential biomarker for neuroinflammation. Together, findings reveal an SMC2-mediated pathway whereby MPP binding promotes SMC2 nuclear translocation, mitigating neuroinflammation via regulation of microglial cell cycle and metabolic homeostasis. Given cell cycle regulation's importance in cellular homeostasis, SMC2 emerges as a promising therapeutic target, and MPP as a candidate agent for neuroinflammatory disorder treatment.
Insights
Millepurpan (MPP), isolated from Astragali Radix, targets SMC2 to reduce neuroinflammation by restoring microglial cell cycle and metabolism. This compound shows promise for treating neurological disorders.
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Microglia are central nervous system immune cells; their dysfunction drives neuroinflammation and neurological disorders.
- Astragali Radix (AR) possesses neuroprotective properties, but its active compounds are not well understood.
- The specific mechanisms of AR's neuroprotective effects require further investigation.
Purpose of the Study:
- To isolate and characterize active compounds from Astragali Radix (AR).
- To investigate the anti-inflammatory effects and molecular mechanisms of Millepurpan (MPP) in microglia.
- To evaluate the therapeutic potential of MPP in neuroinflammatory models.
Main Methods:
- Isolation of Millepurpan (MPP) from AR extract.
- In vitro studies using BV-2 microglial cells stimulated with lipopolysaccharide (LPS).
- Binding assays, cell cycle analysis, Seahorse metabolic analysis, in vivo studies in LPS-treated mice, and reanalysis of single-cell RNA sequencing data.
Main Results:
- MPP was isolated from AR and demonstrated potent anti-inflammatory effects in LPS-stimulated microglia.
- MPP binds to the ATPase head domain of structural maintenance of chromosomes 2 (SMC2), obstructing its ATP-binding pocket.
- MPP restores nuclear SMC2 translocation, promotes cell cycle progression (G1/S transition), reverses LPS-induced glycolytic reprogramming, and exhibits neuroprotective effects in vivo.
Conclusions:
- MPP mitigates neuroinflammation by modulating the SMC2 pathway, regulating microglial cell cycle, and maintaining metabolic homeostasis.
- SMC2 is identified as a potential therapeutic target and biomarker for neuroinflammation.
- MPP represents a promising candidate agent for treating neuroinflammatory disorders.
