Journal: MedComm

Article Title: Spatial Transcriptional Heterogeneity in the Infarct Core and Its Surrounding Regions Targeting Piezo1 Signals in Rats With Myocardial Ischemia‐Reperfusion Injury

doi: 10.1002/mco2.70537

Figure Lengend Snippet: Integration of single‐cell and spatial transcriptomics reveals dynamic activation of Piezo1 after MIR. (A–E) The gene expression of Piezo1, RyR2, MMP2, and Rac1 was specifically upregulated, whereas the SERCA2 was downregulated in the infarcted and incomplete infarct zones. (F and G) Dot plots comparing expression patterns of Piezo1, Ryr2, Mmp2, and Atp2a2 between MIR and control sections. Dot color represents average expression (Exp. avg), and dot size represents the proportion of expressing spots (Exp%). (H) Gene Ontology (GO) enrichment analysis of upregulated genes in the MIRI group. (I) Integration of spatial transcriptomics and scRNA‐seq using RCTD, which mapped cardiomyocytes into eight subclusters (CM1–CM8), visualized by UMAP (top) and projected onto Visium sections (bottom). (J) Dot plot of Piezo1 expression across CM1–CM8. (K) Pseudotime trajectory of cardiomyocytes, color denotes pseudotime rank along the inferred manifold. (L) Heatmap of trajectory‐associated gene modules ordered by pseudotime, stratified by pre‐branch and branch states. (M) GO enrichment results for Module 2. (N) Expression of Module 2 along the two branch states across pseudotime. (O) Feature map of Piezo1 expression over the pseudotime manifold, color denotes log‐normalized expression. (P) Piezo1 expression along pseudotime for CM1–CM8, showing subcluster‐specific dynamics.

Article Snippet: The membranes were blocked with 5% nonfat milk in TBST (Tris‐buffered saline with 0.1% Tween 20) at room temperature for 1 h. Subsequently, the membranes were incubated overnight at 4°C with the primary antibodies against Piezo1 (1:1000, A4340, ABclonal), Ryr2 (1:1000, 19765‐1‐AP, Proteintech), SERCA2 (1:1000, ab150453, Abcam), and MMP2 (1:1000, ab92536, Abcam).

Techniques: Activation Assay, Gene Expression, Expressing, Control

Journal: MedComm

Article Title: Spatial Transcriptional Heterogeneity in the Infarct Core and Its Surrounding Regions Targeting Piezo1 Signals in Rats With Myocardial Ischemia‐Reperfusion Injury

doi: 10.1002/mco2.70537

Figure Lengend Snippet: Piezo1 may mediate myocardial ischemia‐reperfusion injury through activation of MMP2–RyR2/SERCA2 signaling. (A) Representative Western blots and quantification showing protein levels of Piezo1, RyR2, SERCA2, and MMP2 proteins in the left ventricle from rats that underwent IR (30 min of ischemia followed by 2 h of reperfusion) or Sham. Sham and I/R group samples were obtained from separate cohorts of four rats each, with I/R samples collected distal to the ligation site. Each target band was first normalized with GAPDH, and then the fold change was calculated versus the Sham group ( n = 4). (B–E) Representative immunofluorescence images showing expression of Piezo1 (B), RyR2 (C), SERCA2 (D), and MMP2 (E) (magenta) co‐stained with ACTN2 (green) in sections from another set of Sham rats and I/R rats, with the latter obtained distal to the ligation site. Scale bars = 10 µm ( n = 4). (F) Ca 2+ fluorescent staining with Fluo‐4 AM in H9C2 cells (left) and quantification of the Ca 2+ fluorescence intensity (right, n = 4). (G) Potential model indicating Piezo1 mediation of myocardial ischemia‐reperfusion injury through activation of MMP2–RyR2/SERCA2 signaling.

Article Snippet: The membranes were blocked with 5% nonfat milk in TBST (Tris‐buffered saline with 0.1% Tween 20) at room temperature for 1 h. Subsequently, the membranes were incubated overnight at 4°C with the primary antibodies against Piezo1 (1:1000, A4340, ABclonal), Ryr2 (1:1000, 19765‐1‐AP, Proteintech), SERCA2 (1:1000, ab150453, Abcam), and MMP2 (1:1000, ab92536, Abcam).

Techniques: Activation Assay, Western Blot, Ligation, Immunofluorescence, Expressing, Staining, Fluorescence