Targeting the PHD2/HIF-1α/HO-1 pathway: A key role of trimetazidine in hypertensive nephropathy.

OBJECTIVE

This study seeks to unravel the effects of trimetazidine (TMZ) on hypertensive nephropathy (HN) in mice and its underlying mechanisms.

METHODS

Sixty male 129 mice (8-10 weeks old) were randomly categorized into six groups (n = 10 per group): control, model, TMZ, TMZ + small interfering RNA targeting prolyl hydroxylase domain protein 2 (si-PHD2), TMZ + zinc protoporphyrin [ZnPP, a heme oxygenase-1 (HO-1) inhibitor], and TMZ + KC7F2 [a hypoxia-inducible factor-1 alpha (HIF-1α) inhibitor]. All groups except the control group received angiotensin II to induce HN models. TMZ was administered by gavage for 28 days, while the other TMZ-based groups received additional si-PHD2, ZnPP, or KC7F2. Blood pressure, renal function, proinflammatory cytokines, and kidney pathology were measured. Protein/mRNA levels of PHD2, HO-1, HIF-1α, and Collagen I were analyzed via reverse transcription quantitative polymerase chain reaction/Western blot.

RESULTS

The model group showed increased blood pressure, renal injury, fibrosis, and elevated levels of PHD2, HIF-1α, HO-1, Collagen I, and inflammatory markers compared to the control group (P < 0.05). TMZ treatment alleviated renal damage and downregulated PHD2, while upregulating HIF-1α and HO-1. These effects were further enhanced by PHD2 knockdown (TMZ + si-PHD2), but reversed by the inhibition of HO-1 or HIF-1α (TMZ + ZnPP, TMZ + KC7F2).

CONCLUSION

TMZ improves HN in mice by modulating the PHD2/HIF-1α/HO-1 pathway.