PGC-1α Agonist Rescues Doxorubicin-Induced Cardiomyopathy by Mitigating the Oxidative Stress and Necroptosis

Figures

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  Figure 1. Doxorubicin-induced model of cardiomyopathy. (a) Schematic diagram of dose schedule for doxorubicin-induced cardiomyopathy model. (b) Micrograph of cardiac tissue (upper right panel) and quantification of left ventricular area (lower right panel). (c) Hematoxylin and eosin staining of control and doxorubicin-treated heart. LV = Left Ventricle, RV = Right Ventricle. Scale bar = 50 µm, (*) = p < 0.05.

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  Figure 2. (a) Analysis of cardiac tissue fibrosis via Masson Trichrome Staining (muscle tissue = pink to red, collagen deposition = blue and nucleus = black), Picro-Sirius Red staining (muscle tissue, cell cytoplasm = yellow, collagen deposits = red and nucleus = black), and α-SMA (blue = nucleus and green = α-SMA). Scale = 50 μm. (b) qPCR-based transcripts expression for necroptosis markers (RIPK1, RIPK3, MLKL). (c) Immunofluorescence of necroptosis markers (RIPK1, RIPK3 and MLKL) in control and doxorubicin-treated groups. Magnification = 40×. (d) Quantification of immunofluorescence data. ns = non-significant, (****) = p < 0.0001.

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  Figure 3. PGC-1α agonist (ZLN005)-based intervention to rescue doxorubicin-induced model of cardiomyopathy. (a) Schematic diagram of dose schedule for ZLN005-based intervention in doxorubicin-induced cardiomyopathy model. (b) Micrograph of cardiac tissue (top) and hematoxylin and eosin staining (bottom) of doxorubicin-treated heart and intervention group. Scale bar = 50 µm. (c) Quantification of left ventricular area. (d) Comparison of body weights of mice with time (in days) in all the study groups. LV = Left Ventricle, RV = Right Ventricle. ns = non-significant, (*) = p < 0.05, (**) = p < 0.01.

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  Figure 4. (a) Analysis of fibrosis via Masson Trichrome Staining (muscle tissue = pink to red, collagen = blue and nucleus = black), Picro-Sirius Red staining (muscle tissue, cell cytoplasm = yellow, collagen = red and nucleus = black), and α-SMA (blue = nucleus and green = staining of α-SMA) in DOX, ZLN005, and ZLN005 + DOX groups. Scale bar = 50 μm. (b) qPCR-based transcripts expression for necroptosis markers (RIPK1, RIPK3, MLKL). (c) Immunofluorescence of necroptosis markers (RIPK1, RIPK3, and MLKL) in study groups. Magnification = 40×. (d) Quantification of immunofluorescence data. ns = non-significant, (**) = p < 0.01, (****) = p < 0.0001.

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  Figure 5. Transcript expression levels (qPCR) of alarmin molecules in control, DOX, ZLN005 and ZLN005 + Dox hearts. CTSB = Cathepsin-B, HMGB1 = High Mobility Group Box-1, S100b = S100 calcium binding protein B, ns = non-significant (significant p value is set as p < 0.05).

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  Figure 6. (a–g) Status of oxidative stress markers in cell lysates of cardiac tissue of control, DOX, ZLN005, and ZLN005 + DOX groups. (h–l) Tissue remodeling parameters for cardiac cell lysates of all the study groups. 8-OHdG = (8-oxo-7,8-dihydro-2′-deoxyguanosine), GSH: GSSG = ratio of glutathione to glutathione reductase. (*) = p < 0.05, (**) = p < 0.01, (***) = p < 0.001, (****) = p < 0.0001.

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  Figure 7. Schematic representation of DOX-induced cardiotoxic effects (enhanced oxidative stress, necroptosis, fibrosis, and cardiac remodeling) which were mitigated by PGC-1α agonist, i.e., ZLN005. (? = require further investigation). DOX= doxorubicin, DICM = DOX-induced cardiomyopathy, ECM = Extracellular Matrix.