Figure 7.

In vivo transfer of MALAT1-overexpressing dendritic cells (DCs) deferred autoimmune myocarditis progression. After induction of experimental autoimmune myocarditis (EAM) (immunization with α-myosin H-chain peptide), mice were transfused with MALAT1-overexpressing DCs, LPS-DC, or phosphate-buffered saline (PBS), respectively. Hearts were collected on day 21 post-immunization. (A) Consecutive cardiac sections were stained with hematoxylin and eosin (H&E) (original magnification 20×). (B) Analysis of H&E staining by grading as described in Section “Materials and Methods.” Transfusion with MALAT1-overexpressing DCs significantly alleviated acute myocardial inflammation in EAM mice compared with PBS transfusion. (C–E) Myocardial function was evaluated by echocardiography (C) on day 42 post-immunization, and the parameters of LVEDDs (E) and EF (D) were as shown. Animals injected with MALAT1-overexpressing DCs showed less LV and LVEDDs and more EF than did those that received LPS-DCs and PBS transfusion. (F–I) Splenic T cells were separated from EAM mice at day 21 post-immunization. (F) IL10, IL12, and IL6 production in the serum of EAM mice was detected by ELISA. The expressions of IL12 and IL6 were significantly decreased and that of IL10 was increased in mice injected with pMALAT1-DCs. (G) BrdU-ELISA determined the proliferating activity of splenic T cells. (H,I) Tregs (CD4⁺CD25⁺Foxp3⁺) in splenic T cells were assessed by flow cytometry (H) and are shown as percentages (I). Filled histograms represent isotype-matched irrelevant specificity controls. The data are presented as the mean ± SD from at least three independent experiments. *P < 0.05; **P < 0.01.