Myocardial damage post short-term self-administration cocaine usage in rat

Abstract

Cocaine abuse remains a significant risk with profound adverse impact on cardiovascular health. While long-term cocaine addiction-induced cardiotoxicity is well-documented, the underlying mechanism and the molecular effects of short-term recreational usage of cocaine on the heart have not been well studied. We established a short-term cocaine exposure rat model through self-administration, mimicking real-world recreational cocaine usage. Our results indicate that even such short-term cocaine usage induces deleterious effect on the heart including pathological remodeling and transcriptome reprogramming associated with major metabolic and contractile processes. This study sheds important insight on the molecular mechanisms of short-term exposure of cocaine-induced cardiovascular damage.

Keywords: Cocaine; Mitochondria; Myocardial damage; Transcriptome.

Graphical abstract

Fig. 1

Short-term recreational cocaine usage induced transcriptome remodeling in rat hearts A. Schematic view of experimental design. B. Infusion amount during acquisition days between saline and cocaine self-administration groups. Saline SA n = 8, cocaine SA n = 9 rats over indicated time points. ****, p < 0.001, two-way repeated measures ANOVA was used for statistical analysis. C. Infusion amount throughout the self-administration days between saline and cocaine self-administration groups. Saline SA n = 8, cocaine SA n = 9 rats over indicated time point. ****, p < 0.001, two-way repeated measures ANOVA was used for statistical analysis. D. Cumulative cocaine intake in saline and cocaine self-administration rat groups. Saline SA n = 8, cocaine SA n = 9 rats ****, p < 0.001, student t-test was used for statistical analysis. E. Body weight in saline and cocaine self-administration rat groups. Saline SA n = 5, cocaine SA n = 5 rats *, p < 0.05, student t-test was used for statistical analysis. F–G. Western blot (F) and quantification (G) for TH (tyrosine hydroxylase) protein expression in adrenal gland tissues in saline and cocaine self-administration rat groups. Saline SA n = 5, cocaine SA n = 5 rats adrenal gland tissues, *, p < 0.05, student t-test was used for statistical analysis in G. H. H&E staining for cardiac section in saline and cocaine self-administration rat groups. Scale bar: 1 mm I–J. Masson Trichrome staining (I) and quantification (J) for rat cardiac section. Saline SA n = 3, cocaine SA n = 3 rat hearts were stained, each heart was quantified under three different areas/views. ****, p < 0.001, Scale bar: 250 μm. Student t-test was used for statistical analysis. K–L. KEGG pathway analysis for differentially expressed genes in saline and cocaine self-administration rat left ventricle tissues. M–N. Real-time PCR analysis for Pfkp (M) and Epor (N) expression in saline and cocaine self-administration rat heart tissues. Saline SA n = 5, cocaine SA n = 5 rats left ventricle, experiment was performed in duplicate. *, p < 0.05, **, p < 0.01, student t-test was used for statistical analysis. All error bars represent Mean with SEM.

Fig. 2

Short-term recreational cocaine usage induced cardiac pathological remodeling A-B. TUNEL staining (A) and quantification for TUNEL positive cells (B) in saline and cocaine self-administration rat cardiac sections. Saline SA n = 3, cocaine SA n = 3 rat hearts were stained, each heart was quantified under two different areas/views. ****, p < 0.001, student t-test was used for statistical analysis. Scale bar: 200 μm C. Real-time PCR analysis of Bax expression in saline and cocaine self-administration hearts. Saline SA n = 5, cocaine SA n = 5 rats left ventricle tissues were used, experiment was performed in duplicate. *, p < 0.05, student t-test was used for statistical analysis. D-E. WGA staining (D) and cardiomyocytes cross-section area (E) in saline and cocaine self-administration rat hearts. Saline SA n = 3, cocaine SA n = 3 rats were stained, each heart has been quantified under three different areas/views, 30 myocytes were quantified under each view. ****, p < 0.001, student t-test was used for statistical analysis. Scale bar: 200 μm F. Real-time PCR analysis of Nppb expression in saline and cocaine self-administration rat hearts. Saline SA n = 5, cocaine SA n = 5 rat left ventricle tissues were used, experiment was performed in duplicate. *, p < 0.05, student t-test was used for statistical analysis. G-H. Western blot (G) and quantification (H) of mitochondrial complexes in saline and cocaine self-administration rat hearts. Saline SA n = 3, cocaine SA n = 3 rat left ventricle were used, experiment was repeated three times. *, p < 0.05, student t-test was used for statistical analysis. I. Real-time PCR analysis of Cox4l1 expression in saline and cocaine self-administration rat hearts. Saline SA n = 5, cocaine SA n = 5 rat left ventricle tissues were used, experiment was performed in duplicate. ***, p < 0.005, student t-test was used for statistical analysis. All error bars represent Mean with SEM.

Supplementary material 2