This study tested whether combined dapagliflozin and entresto would be superior to mere one therapy on protecting the residual renal function and integrity of kidney parenchyma in hypertensive kidney disease (HKD) rat. In vitro results showed that the protein expressions of oxidative-stress/mitochondrial-damaged (NOX-1/NOX-2/oxidized-protein/cytosolic-cytochrome-C)/apoptotic (mitochondrial-Bax/cleaved caspeases 3, 9)/cell-stress (p-ERK/p-JNK/p-p38) biomarkers were significantly increased in H2O2-treated NRK-52E cells than those of controls that were reversed by dapagliflozin or entresto treatment. Adult-male SD rats (n = 50) were equally categorized into group 1 (sham-operated-control), group 2 (HKD by 5/6 nephrectomy + DOCA-salt/25 mg/kg/subcutaneous injection/twice weekly), group 3 (HKD + dapagliflozin/orally, 20 mg/kg/day for 4 weeks since day 7 after HKD induction), group 4 (HKD + entresto/orally, 100 mg/kg/day for 4 weeks since day 7 after HKD induction), and group 5 (HKD + dapagliflozin + entresto/the procedure and treatment strategy were identical to groups 2/3/4). By day 35, circulatory levels of blood-urine-nitrogen (BUN)/creatinine and urine protein/creatinine ratio were lowest in group 1, highest in group 2, and significantly lower in group 5 than in groups 3/4, but no difference between groups 3/4. Histopathological findings showed the kidney injury score/fibrotic area/cellular expressions of oxidative-stress/kidney-injury-molecule (8-OHdG+/KIM-1+) exhibited an identical trend, whereas the cellular expressions of podocyte components (synaptopodin/ZO-1/E-cadherin) exhibited an opposite pattern of BUN level among the groups. The protein expressions of oxidative stress/mitochondrial-damaged (NOX-1/NOX-2/oxidized protein/cytosolic-cytochrome-C/cyclophilin-D)/apoptotic (mitochondrial-Bax/cleaved-caspase 3)/mitochondrial-fission (PINK1/Parkin/p-DRP1)/autophagic (LC3BII/LC3BI ratio, Atg5/beclin-1)/MAPK-family (p-ERK/p-JNK/p-p38) biomarkers displayed a similar pattern, whereas the protein expression of mitochondria-biogenesis signaling (SIRT1/PGC-1α-Mfn2/complex I-V) displayed an opposite pattern of BUN among the groups. In conclusion, combined dapagliflozin-entresto therapy offered additional benefits on protecting the residual kidney function and architectural integrity in HKD rat.
Keywords: Chronic kidney disease; dapagliflozin; entresto; hypertension; kidney ultrastructure; renal function.