Journal: Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease

Article Title: Recombinant Extracellular Domain (p75ECD) of the Neurotrophin Receptor p75 Attenuates Myocardial Ischemia–Reperfusion Injury by Inhibiting the p‐JNK/Caspase‐3 Signaling Pathway in Rat Microvascular Pericytes

doi: 10.1161/JAHA.119.016047

Figure Lengend Snippet: AN (the myocardial infarct size), which was evaluated at 24 hours after reperfusion, was expressed as a percentage of AAR ( AN / AAR ). Compared with the I/R group, when given at 5 minutes before reperfusion (posttreatment), p75 NTR ectodomain (p75 ECD ‐Fc) at a dose of 3 mg/kg reduced AN / AAR . p75 ECD ‐induced cardioprotection was not altered by SP 600125, an inhibitor of JNK . Data are expressed as mean± SD . n=8 rats/group. * P <0.05, as compared with the I/R group. AAR indicates area at risk; AN , area of necrosis; I/R, ischemia–reperfusion; JNK , c‐Jun N‐terminal kinase; and p75 NTR , p75 neurotrophin receptor.

Article Snippet: The in vivo myocardial IRI model was established by occluding the left main coronary arteries for 45 minutes to induce ischemia (I) and subsequently relaxing them to achieve reperfusion (R)., Seventy‐two rats were randomly divided into 6 groups (Figure A): (1) Sham group, undergoing operation and snare placement without ligation; (2) I/R group, receiving I for 45 minutes and a subsequent R; (3–5) p75ECD groups, undergoing the same treatment as the I/R group and receiving a tail‐vein injection of p75ECD (1, 3, or 9 mg/kg, respectively), a p75NTR extracellular domain‐human IgG Fc fusion protein, 5 minutes before R (posttreatment); and (6) p75ECD+SP600125 group, receiving I for 45 minutes and a subsequent R, and a tail‐vein injection of 3 mg/kg p75ECD and 20 mg/kg SP600125 (JNK pathway inhibitor, MCE, USA) 5 minutes before R. Eight animals from each group received a 24‐hour R. In the Sham, I/R, and 3 mg/kg p75ECD groups, another 8 animals received a 28‐day R. To test the effects of SP600125 alone on myocardial IRI, an additional 16 wild‐type rats were divided into 2 groups (n=8): I/R group, receiving I for 45 minutes and a subsequent 24‐hour R; SP600125 group, receiving I for 45 minutes and a subsequent 24‐hour R, and a tail‐vein injection of 20 mg/kg SP600125.

Techniques:

Journal: Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease

Article Title: Recombinant Extracellular Domain (p75ECD) of the Neurotrophin Receptor p75 Attenuates Myocardial Ischemia–Reperfusion Injury by Inhibiting the p‐JNK/Caspase‐3 Signaling Pathway in Rat Microvascular Pericytes

doi: 10.1161/JAHA.119.016047

Figure Lengend Snippet: A , Evan's blue and TTC staining were used to evaluate the myocardial infarct size at 24 hours after reperfusion (Data are shown in Figure ). As representative pictures show in (A.1, A.2, and A.3), for each short‐axis sections of the left ventricles from hearts, blue areas indicate nonischemic tissue; white areas indicate infarcted tissue; and red areas represent risk region. B , Echocardiography was performed to determine whether the reduced infarct size by p75 ECD at 24 hours R may further confer an improvement in the cardiac function at 28 days after reperfusion. Representative echocardiograms in M‐mode from 3 groups are shown in (B.1, B.2, and B.3). Data are shown in bar chart ( D and E ). C , Masson's trichrome staining was conducted to assess whether the attenuated myocardial fibrosis was involved in p75 ECD ‐induced protection at 28 days after reperfusion. Representative pictures are shown in (B.1, B.2, and B.3). Normal myocardium is red, and collagen matrix (fibrosis area) is blue. Rectangular marker indicates a region that was chosen for representative Masson's trichrome micrographs. Data are shown in bar chart ( F ). R, reperfusion. Bars in ( A )=5 mm, and 100 μm in ( C ). All values are expressed as mean± SD . n=8 rats/group. * P <0.01, as compared with the I/R group. d indicates days; h, hours; I/R, ischemia–reperfusion; LVEDd, left ventricular end‐diastolic diameter; LVEF, left ventricular ejection fraction; LVFS, left ventricular fractional shortening; p75 ECD , ectodomain of p75NTR; and TTC, triphenyltetrazolium chloride.

Article Snippet: The in vivo myocardial IRI model was established by occluding the left main coronary arteries for 45 minutes to induce ischemia (I) and subsequently relaxing them to achieve reperfusion (R)., Seventy‐two rats were randomly divided into 6 groups (Figure A): (1) Sham group, undergoing operation and snare placement without ligation; (2) I/R group, receiving I for 45 minutes and a subsequent R; (3–5) p75ECD groups, undergoing the same treatment as the I/R group and receiving a tail‐vein injection of p75ECD (1, 3, or 9 mg/kg, respectively), a p75NTR extracellular domain‐human IgG Fc fusion protein, 5 minutes before R (posttreatment); and (6) p75ECD+SP600125 group, receiving I for 45 minutes and a subsequent R, and a tail‐vein injection of 3 mg/kg p75ECD and 20 mg/kg SP600125 (JNK pathway inhibitor, MCE, USA) 5 minutes before R. Eight animals from each group received a 24‐hour R. In the Sham, I/R, and 3 mg/kg p75ECD groups, another 8 animals received a 28‐day R. To test the effects of SP600125 alone on myocardial IRI, an additional 16 wild‐type rats were divided into 2 groups (n=8): I/R group, receiving I for 45 minutes and a subsequent 24‐hour R; SP600125 group, receiving I for 45 minutes and a subsequent 24‐hour R, and a tail‐vein injection of 20 mg/kg SP600125.

Techniques: Staining, Marker

Journal: Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease

Article Title: Recombinant Extracellular Domain (p75ECD) of the Neurotrophin Receptor p75 Attenuates Myocardial Ischemia–Reperfusion Injury by Inhibiting the p‐JNK/Caspase‐3 Signaling Pathway in Rat Microvascular Pericytes

doi: 10.1161/JAHA.119.016047

Figure Lengend Snippet: The coverage of pericytes/endothelial cells and microvascular leakage, which are indices of microvascular dysfunction, were detected by IF staining at 28 days after reperfusion. A through C , Representative confocal IF micrographs for the expression of PDGFR ‐β (a marker of pericytes), CD 31 (a marker of endothelial cells), CD 68 (a marker of macrophages), and ICAM ‐2. The nuclei were stained blue by DAPI , CD 31, and ICAM ‐2 red by Texas‐Red, and PDGFR ‐β and CD 68 green by FITC staining. Positive cells of PDGFR‐β/CD31 co‐expression (A) (located in microvasculature), CD68 (B), and ICAM‐2 (C) were shown as merge (white arrows) and calculated for analysis (D, E, and F, respectively). Data are expressed as mean± SD , n=8 rat/group. * P <0.01, as compared with the I/R group. CD 31 indicates cluster of differentiation 31; DAPI , 4′,6‐diamidino‐2‐phenylindole; FITC , fluorescein isothiocyanate; ICAM ‐2, intercellular adhesion molecule‐2; IF , immunofluorescence; I/R, ischemia–reperfusion; PDGFR ‐β, platelet‐derived growth factor receptor‐β; and p75 ECD , ectodomain of p75NTR.

Article Snippet: The in vivo myocardial IRI model was established by occluding the left main coronary arteries for 45 minutes to induce ischemia (I) and subsequently relaxing them to achieve reperfusion (R)., Seventy‐two rats were randomly divided into 6 groups (Figure A): (1) Sham group, undergoing operation and snare placement without ligation; (2) I/R group, receiving I for 45 minutes and a subsequent R; (3–5) p75ECD groups, undergoing the same treatment as the I/R group and receiving a tail‐vein injection of p75ECD (1, 3, or 9 mg/kg, respectively), a p75NTR extracellular domain‐human IgG Fc fusion protein, 5 minutes before R (posttreatment); and (6) p75ECD+SP600125 group, receiving I for 45 minutes and a subsequent R, and a tail‐vein injection of 3 mg/kg p75ECD and 20 mg/kg SP600125 (JNK pathway inhibitor, MCE, USA) 5 minutes before R. Eight animals from each group received a 24‐hour R. In the Sham, I/R, and 3 mg/kg p75ECD groups, another 8 animals received a 28‐day R. To test the effects of SP600125 alone on myocardial IRI, an additional 16 wild‐type rats were divided into 2 groups (n=8): I/R group, receiving I for 45 minutes and a subsequent 24‐hour R; SP600125 group, receiving I for 45 minutes and a subsequent 24‐hour R, and a tail‐vein injection of 20 mg/kg SP600125.

Techniques: Staining, Expressing, Marker, Immunofluorescence, Derivative Assay