HMOX1 and pulmonary arterial hypertension: Zheng W. et al. (2021) established an SCII rat model and a BV2 microglia model induced by oxygen and glucose deprivation/reoxygenation, and found that PAH treatment upregulated the levels of Nrf2 and HO-1 in the spinal cord of SCII rats, confirming that PAH can activate Nrf2/HO -1 pathway, thereby inhibiting the activation of microglia and alleviating inflammation and oxidative stress.