Background Increasing evidence supports the role of heme oxygenase-1 (HO-1) in cytoprotective response and iron homeostasis. The object of this study was to investigate whether adenovirus-mediated gene transfer of HO-1 in arteries reduces iron overload and inhibits lesion formation in apolipoprotein E (apoE)–deficient mice. Methods and Results Infection of rat aortic smooth muscle cells with adenovirus carrying the human HO-1 gene (Adv-HO-1) resulted in a high-level expression of HO-1 protein, which effectively reduced the hemin-induced iron overload in these cells. Adenovirus-mediated gene transfer in arteries in vivo was achieved by direct injection of Adv-HO-1 into the left ventricles of anesthetized animals. Transgene was expressed in the endothelium and aortic lesion of apoE-deficient mice after they had received recombinant adenovirus for 1 week and gradually decayed during the next 5 weeks. When young apoE-deficient mice (14 weeks old) received Adv-HO-1 (2.5×10 ⁹ pfu) for 6 weeks, lesions that developed in the aortic root or aortic arch were significantly smaller than those in control littermates receiving empty viral vector. Furthermore, the iron deposition as well as tissue iron content was much less in aortic tissue of Adv-HO-1–treated mice. The inhibitory effect of HO-1 gene transfer on the progression of advanced lesions was also observed in older apoE-deficient mice (20 weeks old) receiving Adv-HO-1 intraventricularly. Conclusions Overexpression of HO-1 in vascular cells facilitates iron metabolism and attenuates development of atherosclerosis in apoE-deficient mice.

We investigated the molecular mechanism underlying the role of transient receptor potential vanilloid type 1 (TRPV1), a Ca²⁺-permeable non-selective cation channel, in the activation of endothelial nitric oxide (NO) synthase (eNOS) in endothelial cells (ECs) and mice. In ECs, TRPV1 ligands (evodiamine or capsaicin) promoted NO production, eNOS phosphorylation, and the formation of a TRPV1–eNOS complex, which were all abrogated by the TRPV1 antagonist capsazepine. TRPV1 ligands promoted the phosphorylation of Akt, calmodulin-dependent protein kinase II (CaMKII) and TRPV1, and increased the formation of a TRPV1–Akt–CaMKII complex. Removal of extracellular Ca²⁺ abolished the ligand-induced increase in the phosphorylation of Akt and CaMKII, formation of a TRPV1–eNOS complex, and eNOS activation. Inhibition of PI3K and CaMKII suppressed the ligand-induced increase in TRPV1 phosphorylation, formation of a TRPV1–eNOS complex, and eNOS activation. TRPV1 activation increased the phosphorylation of Akt, CaMKII, and eNOS in the aortas of wild-type mice but failed to activate eNOS in TRPV1-deficient aortas. Additionally, TRPV1 ligand-induced angiogenesis was diminished in eNOS- or TRPV1-deficient mice. When compared with apolipoprotein E (ApoE)-deficient mice, ApoE/TRPV1-double-knockout mice displayed reduced phosphorylation of eNOS, Akt, and CaMKII in aortas but worsened atherosclerotic lesions. TRPV1 activation in ECs may trigger Ca²⁺-dependent PI3K/Akt/CaMKII signalling, which leads to enhanced phosphorylation of TRPV1, increased TRPV1–eNOS complex formation, eNOS activation and, ultimately, NO production.

Background. Apoptosis and autophagy may contribute to cell homeostasis in the kidney subjected to ischemia/reperfusion injury via mitochondrial injury. Ischemia/reperfusion induces differential sensitivity between proximal and distal tubules via a dissociated Bcl-xL expression. We hypothesized Bcl-xL augmentation in the proximal and distal tubules may potentially reduce ischemia/reperfusion induced renal dysfunction. Methods. We augmented Bcl-xL protein expression in the kidney with intrarenal adenoviral bcl-xL gene transfer and evaluated the potential effect of Bcl-xL augmentation on ischemia/reperfusion induced renal oxidative stress, apoptosis, and autophagy in the rat. Results. Intrarenal arterial Adv-bcl-xL administration augmented maximal Bcl-xL protein expression of rat kidney after 7 days of transfection. The primary location of Bcl-xL augmentation was found in proximal and distal tubules, but not in glomeruli. Ischemia/reperfusion increased mitochondrial cytochrome C release, renal O₂^−. level and renal 3-nitrosine and 4-hydroxyneonal accumulation, potentiated tubular apoptosis and autophagy, including increase in microtubule-associated protein 1 light chain 3 (LC-3) and Beclin-1 expression, Bax/Bcl-xL ratio, caspase 3 expression and poly-(ADP-ribose)-polymerase fragments, and subsequent proximal and distal tubular apoptosis/autophagy. However, Adv-bcl-xL administration significantly reduced ischemia/reperfusion enhanced mitochondrial cytochrome C release, O₂^−. production, 3-nitrotyrosine and 4-hydroxynonenal accumulation, Beclin-1 expression, Bax/Bcl-xL ratio, and proximal and distal tubular apoptosis/autophagy, consequently improving renal dysfunction. Further study showed that Bcl-xL augmentation was more efficiently than Bcl-2 augmentation in amelioration of ischemia/reperfusion induced proximal and distal tubular apoptosis and renal dysfunction. Conclusions. Our results suggest that Adv-bcl-xL gene transfer significantly improves ischemia/reperfusion-induced renal dysfunction via the downregulation of renal tubular apoptosis and autophagy.

Objective— Brain expresses abundant lipocalin-type prostaglandin (PG) D ₂ (PGD ₂ ) synthase but the role of PGD ₂ and its metabolite, 15-deoxy-Δ ^12,14 PGJ ₂ (15d-PGJ ₂ ) in brain protection is unclear. The aim of this study is to assess the effect of 15d-PGJ ₂ on neuroprotection. Methods and Results— Adenoviral transfer of cyclooxygenase-1 (Adv-COX-1) was used to amplify the production of 15d-PGJ ₂ in ischemic cortex in a rat focal infarction model. Cortical 15d-PGJ ₂ in Adv-COX-1–treated rats was increased by 3-fold over control, which was correlated with reduced infarct volume and activated caspase 3, and increased peroxisome proliferator activated receptor-γ (PPARγ) and heme oxygenase-1 (HO-1). Intraventricular infusion of 15d-PGJ ₂ resulted in reduction of infarct volume, which was abrogated by a PPARγ inhibitor. Rosiglitazone infusion had a similar effect. 15d-PGJ ₂ and rosiglitazone at low concentrations suppressed H ₂ O ₂ -induced rat or human neuronal apoptosis and necrosis and induced PPARγ and HO-1 expression. The anti-apoptotic effect was abrogated by PPARγ inhibition. Conclusion— 15d-PGJ ₂ suppressed ischemic brain infarction and neuronal apoptosis and necrosis in a PPARγ dependent manner. 15d-PGJ ₂ may play a role in controlling acute brain damage induced by ischemia-reperfusion.