Related Experiment Video
Updated: Dec 29, 2025
Isolation and Flow Cytometric Assessment of Neuroimmune Interactions in a Mini-Stroke Murine Model
Published on: June 20, 2025
Brain-Derived Microparticles (BDMPs) Contribute to Neuroinflammation and Lactadherin Reduces BDMP Induced
Zhili Chen1, Michael Chopp1,2, Alex Zacharek1
1Department of Neurology, Henry Ford Hospital, Detroit, MI, United States.
Abstract:
Microparticles (MPs, ~size between 0.1 and 1 mm) are lipid encased containers derived from intact cells which contain antigen from the parent cells. MPs are involved in intercellular communication and regulate inflammation. Stroke increases secretion of brain derived MP (BDMP) which activate macrophages/microglia and induce neuroinflammation. Lactadherin (Milk fat globule-EGF factor-8) binds to anionic phospholipids and extracellular matrices, promotes apoptotic cell clearance and limits pathogenic antigen cross presentation. In this study, we investigate whether BDMP affects stroke-induced neuroinflammation and whether Lactadherin treatment reduces stroke initiated BDMP-induced neuroinflammation, thereby improving functional outcome after stroke. Middle aged (8-9 months old) male C57BL/6J mice were subjected to distal middle cerebral artery occlusion (dMCAo) stroke, and BDMPs were extracted from ischemic brain 24 h after dMCAo by ultracentrifugation. Adult male C57BL/6J mice were subjected to dMCAo and treated via tail vein injection at 3 h after stroke with: (A) +PBS (n = 5/group); (B) +BDMPs (1.5 × 108, n = 6/group); (C) +Lactadherin (400 μg/kg, n = 5/group); (D) +BDMP+Lactadherin (n = 6/group). A battery of neurological function tests were performed and mice sacrificed for immunostaining at 14 days after stroke. Blood plasma was used for Western blot assay. Our data indicate: (1) treatment of Stroke with BDMP significantly increases lesion volume, neurological deficits, blood brain barrier (BBB) leakage, microglial activation, inflammatory cell infiltration (CD45, microglia/macrophages, and neutrophils) into brain, inflammatory factor (TNFα, IL6, and IL1β) expression in brain, increases axon/white matter (WM) damage identified by decreased axon and myelin density, and increases inflammatory factor expression in the plasma when compared to PBS treated stroke mice; (2) when compared to PBS and BDMP treated stroke mice, Lactadherin and BDMP+Lactadherin treatment significantly improves neurological outcome, and decreases lesion volume, BBB leakage, axon/WM injury, inflammatory cell infiltration and inflammatory factor expression in the ischemic brain, respectively. Lactadherin treatment significantly increases anti-inflammatory factor (IL10) expression in ischemic brain and decreases IL1β expression in plasma compared to PBS and BDMP treated stroke mice, respectively. BDMP increases neuroinflammation and aggravates ischemic brain damage after stroke. Thus, Lactadherin exerts anti-inflammatory effects and improves the clearance of MPs to reduce stroke and BDMP induced neurological deficits.
Insights
Brain derived microparticles (BDMPs) worsen stroke-induced neuroinflammation and brain damage. Lactadherin treatment reduces this inflammation and improves functional outcomes after stroke by enhancing microparticle clearance.
Area of Science:
- Neuroscience
- Immunology
- Biochemistry
Background:
- Microparticles (MPs) are cell-derived vesicles involved in intercellular communication and inflammation.
- Stroke elevates brain-derived MPs (BDMPs), which promote neuroinflammation by activating microglia and macrophages.
- Lactadherin facilitates apoptotic cell clearance and limits antigen presentation.
Purpose of the Study:
- To investigate the role of BDMPs in stroke-induced neuroinflammation.
- To determine if Lactadherin treatment can mitigate BDMP-induced neuroinflammation and improve stroke outcomes.
Main Methods:
- Middle-aged male C57BL/6J mice underwent distal middle cerebral artery occlusion (dMCAo) to induce stroke.
- Brain-derived MPs (BDMPs) were isolated from ischemic brain tissue.
- Mice were treated with PBS, BDMPs, Lactadherin, or BDMP+Lactadherin via tail vein injection post-stroke. Neurological function, lesion volume, blood-brain barrier integrity, inflammatory markers, and white matter damage were assessed.
Main Results:
- BDMP treatment significantly exacerbated stroke-induced lesion volume, neurological deficits, blood-brain barrier leakage, microglial activation, inflammatory cell infiltration, and pro-inflammatory cytokine expression (TNFα, IL6, IL1β).
- BDMP treatment also increased white matter damage and plasma inflammatory markers.
- Lactadherin treatment, alone or combined with BDMPs, significantly improved neurological outcomes, reduced lesion volume, BBB leakage, white matter injury, and inflammatory cell infiltration. Lactadherin increased anti-inflammatory IL10 in the brain and decreased IL1β in plasma.
Conclusions:
- Brain-derived microparticles significantly contribute to neuroinflammation and brain damage following stroke.
- Lactadherin treatment demonstrates potent anti-inflammatory effects, reduces microparticle-induced neurological deficits, and improves functional recovery after stroke.
- Lactadherin may represent a therapeutic strategy for mitigating stroke-related brain injury by modulating microparticle-driven inflammation.
