Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Biochemistry

The regulation by immune checkpoints is able to prevent excessive tissue damage caused by ischemia/reperfusion (I/R); therefore, the study aims to investigate the behavior of phosphoprotein associated with glycosphingolipid-enriched microdomains 1 (PAG1) mRNA, miR-1206 and small nucleolar RNA host gene 14 (SNHG14) during I/R and intake of pentoxifylline (PTX) as a protective drug.The relative expression level of PAG1/miR- 1206/SNHG14 was determined by qRT-PCR. Cardiac tissue levels of cytotoxic T-lymphocyte associated antigen 4 (CTLA4) and PAG1 protein expression were determined by ELISA technique. The regulatory T cells were achieved by the flow cytometry. The results indicated that the relative expression of SNHG14 was significantly up regulated in I/R, but suppressed in PTX treated groups with enhancement of the relative expression level of miR-1206. The gene and protein expression of PAG1 were down regulated with effective doses of PTX.The results showed that PTX dose between 30 and 40 mg/kg suppressed the CTLA4 development significantly.The mean of the regulatory T cell in PTX protective groups was significantly reduced at (p < 0.001) in a comparison with I/R group. Spearman{u2019}s correlation analysis revealed a significant negative correlation between SNHG14 and miR-1206, while a significant positive correlation between SNHG14 and PAG1 in I/R heart tissue. Based on the obtained results it is concluded that miR-1206 and SNHG14 may be used as biomarkers with perfect sensitivity and specificity in I/R. Further of PTX also reduced cardiac tissue damage

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