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Updated: May 31, 2026
Isolation and Flow Cytometric Assessment of Neuroimmune Interactions in a Mini-Stroke Murine Model
Published on: June 20, 2025
Lack of macrophage migration inhibitory factor in mice does not affect hallmarks of the inflammatory/immune response
Ana R Inácio1, Richard Bucala, Tomas Deierborg
1Laboratory for Experimental Brain Research, Department of Clinical Sciences, Lund University, BMC A13, 22184 Lund, Sweden. ana.inacio@med.lu.se
Background:
Macrophage migration inhibitory factor (MIF) has been proposed to play a detrimental role in stroke. We recently showed that MIF promotes neuronal death and aggravates neurological deficits during the first week after experimental stroke, in mice. Since MIF regulates tissue inflammation, we studied the putative role of MIF in post-stroke inflammation.
Methods:
We subjected C57BL/6 mice, Mif-/- (MIF-KO) or Mif+/+ (WT), to a transient occlusion of the right middle cerebral artery (tMCAo) or sham-surgery. We studied MIF expression, GFAP expression and the number of CD74-positive cells in the ischemic brain hemisphere 7 days after tMCAo using primarily immunohistochemistry. We determined IFN-γ, IL-2, IL-4, IL-5, IL-10, IL-12, KC/CXCL-1 and TNF-α protein levels in the brain (48 h after surgery) and serum (48 h and 7 days after surgery) by a multiplex immunoassay.
Results:
We observed that MIF accumulates in neurons and astrocytes of the peri-infarct region, as well as in microglia/macrophages of the infarct core up to 7 days after stroke. Among the inflammatory mediators analyzed, we found a significant increase in cerebral IL-12 and KC levels after tMCAo, in comparison to sham-surgery. Importantly, the deletion of Mif did not significantly affect the levels of the cytokines evaluated, in the brain or serum. Moreover, the spleen weight 48 h and 7 days subsequent to tMCAo was similar in WT and MIF-KO mice. Finally, the extent of GFAP immunoreactivity and the number of MIF receptor (CD74)-positive cells within the ischemic brain hemisphere did not differ significantly between WT and MIF-KO mice subjected to tMCAo.
Conclusions:
We conclude that MIF does not affect major components of the inflammatory/immune response during the first week after experimental stroke. Based on present and previous evidence, we propose that the deleterious MIF-mediated effects in stroke depend primarily on an intraneuronal and/or interneuronal action.
Insights
Macrophage migration inhibitory factor (MIF) does not significantly impact post-stroke inflammation in mice. Previous detrimental effects of MIF in stroke are likely due to intraneuronal actions, not immune responses.
Area of Science:
- Neuroscience
- Immunology
- Stroke Research
Background:
- Macrophage migration inhibitory factor (MIF) is implicated in stroke pathology.
- Previous research indicated MIF exacerbates neuronal death and neurological deficits post-stroke.
Purpose of the Study:
- To investigate the role of MIF in the post-stroke inflammatory response.
- To determine if MIF influences key inflammatory mediators and cellular responses in the ischemic brain.
Main Methods:
- Transient middle cerebral artery occlusion (tMCAo) was performed on wild-type (WT) and MIF-deficient (MIF-KO) mice.
- Immunohistochemistry was used to assess MIF, GFAP, and CD74 expression.
- Multiplex immunoassay measured protein levels of various cytokines in brain and serum.
Main Results:
- MIF was found in neurons, astrocytes, and microglia/macrophages in the ischemic brain.
- Cerebral IL-12 and KC levels increased post-tMCAo, but MIF deletion did not alter these or other cytokine levels.
- GFAP immunoreactivity and CD74-positive cell counts were similar in WT and MIF-KO mice.
Conclusions:
- MIF does not significantly modulate the major inflammatory and immune responses within the first week after experimental stroke.
- The detrimental effects of MIF in stroke are proposed to stem from intraneuronal or interneuronal mechanisms rather than systemic inflammation.
