Aryl Hydrocarbon Receptor (AhR) and Vascular Endothelial Growth Factor (VEGF) Crosstalk in Doxorubicin Nephrotoxicity: Mechanisms and Therapeutic Perspectives

Figures

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  Figure 1. Expermintal animal design. A schematic illustration of the experimental design and treatment protocol used in the animal study. The dose of curcumin nanoparticles (CUR-NP) was selected based on our previously published work [24], while the doxorubicin (DOX) dose was chosen according to established protocols reported in the literature [25].

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  Figure 2. Effects of curcumin nanoparticles (CUR-NP) on body and kidney weight parameters in doxorubicin (DOX)-induced nephrotoxicity. CUR-NP treatment did not alter body weight loss (A), significantly reduced kidney weight increase (B), and had no effect on the kidney weight-to-body weight ratio (C) in DOX-treated rats. Data are presented as mean ± SEM (n = 8). Statistical significance is indicated as follows: ns, not significant; * p < 0.05; ** p < 0.01; *** p < 0.001. DOX, doxorubicin; CUR-NP, curcumin nanoparticles.

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  Figure 3. CUR-NP improves kidney function markers in DOX-induced nephrotoxicity in rats. Data are expressed as mean ± SEM (n = 8). (ns; non significant, ** p < 0.01, *** p < 0.001). DOX, doxorubicin, CUR-NP, curcumin-nanoparticle.

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  Figure 4. Representative kidney sections are shown (scale bar = 100 µm). (A) Kidney section from a normal control rat exhibiting normal renal cortical architecture with intact renal corpuscles (arrowheads) and renal tubules (arrow). (B) Kidney section from a CUR-NP–treated rat showing preserved renal corpuscles (arrowhead) and tubular structures (arrow) comparable to the control group. (C) Kidney section from a doxorubicin (DOX)-treated rat demonstrating extensive degeneration of renal corpuscles (arrowhead) and tubular damage characterized by luminal casts and degenerated epithelial lining (arrows). (D) Kidney section from a rat treated with DOX and CUR-NP showing a marked attenuation of DOX-induced pathological alterations in both renal corpuscles (arrowhead) and renal tubules (arrows).

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  Figure 5. CUR-NP improves renal pro-inflammatory mediators (A) NF-κB-P65, (B) TNF-α, and (C) IL-6 in DOX-induced nephrotoxicity in rats. Data are expressed as mean ± SEM (n = 8). (ns; non significant, *** p < 0.001). DOX, doxorubicin, CUR-NP, curcumin-nanoparticle.

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  Figure 6. Effect of CUR-NP on renal AhR and VEGF expression. (A) Representative Western blotting of AhR, VEGF, and β-actin. (B,C) CUR-NP down-regulated renal AhR and VEGF, respectively. Data are expressed as mean ± SEM (ns; non-significant, * p < 0.05, ** p < 0.01, *** p < 0.001). DOX, doxorubicin, CUR-NP, curcumin-nanoparticle.

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  Figure 7. Vascular endothelial growth factor (VEGF) immunohistochemical expression in renal tissue. (A) Representative VEGF-immuno-stained kidney sections (scale bar = 50 µm). (Control) Kidney section from a normal control rat showing absence of VEGF immunoreactivity in the epithelial cells of renal corpuscles (arrowheads) and renal tubules (arrow). (CUR-NP) Kidney section from a CUR-NP–treated rat exhibiting similarly negative VEGF immunoreactivity in renal corpuscles (arrowhead) and tubules (arrow). (DOX) Kidney section from a doxorubicin (DOX)-treated rat demonstrating marked VEGF immunopositivity in renal corpuscles (arrowhead) and renal tubules (arrows). (DOX + CUR-NP) Kidney section from a rat treated with DOX and CUR-NP showing a pronounced reduction in VEGF immunoreactivity in both renal corpuscles (arrowhead) and tubules (arrows). (B) Quantitative analysis of VEGF-immuno-positive cells in renal tissue. Data are expressed as mean ± SEM. Statistical significance is indicated as follows: ns, not significant; * p < 0.05; *** p < 0.001. DOX, doxorubicin; CUR-NP, curcumin nanoparticles.

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  Figure 8. Aryl hydrocarbon receptor (AhR) immunohistochemical expression in renal tissue. (A) Representative AhR-immuno-stained kidney sections (scale bar = 50 µm). (Control) Kidney section from a normal control rat showing absence of AhR immunoreactivity in renal corpuscles (arrowheads) and renal tubules (arrow). (CUR-NP) Kidney section from a CUR-NP–treated rat exhibiting similarly negative AhR immunoreactivity in renal corpuscles (arrowhead) and renal tubules (arrow). (DOX) Kidney section from a doxorubicin (DOX)-treated rat showing marked AhR immunopositivity in tubular epithelial cells lining the renal tubules (arrows), while renal corpuscle cells remain unstained (arrowheads). (DOX + CUR-NP) Kidney section from a rat treated with DOX and CUR-NP demonstrating a pronounced reduction in AhR immunoreactivity in renal tubular cells (arrows), with renal corpuscle cells remaining negative (arrowheads). (B) Quantitative analysis of AhR-immunopositive reactions in renal tissue. Data are expressed as mean ± SEM. Statistical significance is indicated as follows: ** p < 0.01; *** p < 0.001. DOX, doxorubicin; CUR-NP, curcumin nanoparticles.