Figure 3.

The ipsilateral hemisphere is distinguished by CD3⁺ FoxP3⁺ T_H cell recruitment and differential regulation of S1P receptors after acute ischemic stroke. (A) mRNA levels of CD3, STAT3, and FoxP3 were quantified by measuring fold change (FC) normalized to GAPDH expression in the murine brain (24 h) after MCAO. An expansion of CD3⁺ regulatory T_H cells was observed in the ipsilateral hemisphere. (B) Likewise, mRNA levels of the sphingosine 1-phosphate receptors S1P₁, S1P₂, S1P₃, S1P₄, and S1P₅, respectively, were quantified. In particular, S1P₁ was subject to a downregulation as opposed to upregulated S1P₂ and S1P₃ in the ipsilateral hemisphere. The Mann–Whitney U-test was applied to calculate statistical differences between sham (S) and the contralateral hemisphere (CL) or ipsilateral hemisphere (IL) in MCAO-treated mice. A Wilcoxon test was used when comparing CL with IL. In (A), each data point refers to the average of four homogenized whole brain lysates (sham), or half-brain lysates, i.e., ipsilateral or contralateral, respectively. The data are presented as median ± IQR; * p < 0.05, ** p < 0.01, **** p < 0.0001.