ABSTRACT
BACKGROUNDS AND AIMS: Unexplained iron deficiency is associated with poorer survival in patients with pulmonary hypertension (PH). Bone morphogenetic protein (BMP) signaling and BMP protein type II receptor (BMPR2) expression are important in the pathogenesis of PH. BMP6 in hepatocytes is a central transcriptional regulator of the iron hormone hepcidin that controls systemic iron balance. This study aimed to investigate the effects of BMP signaling on iron metabolism and its implication in hypoxia-induced PH. METHODS AND RESULTS: PH was induced in Sprague-Dawley Rats under hypoxia for 4 weeks. Compared with the control group, right ventricular systolic pressure and right ventricle hypertrophy index were both markedly increased, and serum iron level was significantly decreased with iron metabolic disorder in the hypoxia group. In cultured human pulmonary artery endothelial cells (HPAECs), hypoxia increased oxidative stress and apoptosis, which were reversed by supplementation with Fe agent. Meanwhile, iron chelator deferoxamine triggered oxidative stress and apoptosis in HPAECs, and treatment with antioxidant alleviated iron-deficiency-induced apoptosis by reducing reactive oxygen species production. Expression of hepcidin, BMP6 and hypoxia-inducible factor (HIF)-1α were significantly upregulated, while expression of BMPR2 was downregulated in hepatocytes in the hypoxia group, both in vivo and in vitro. Expression of hepcidin and HIF-1α were significantly increased by BMP6, while pretreatment with siRNA-BMPR2 augmented the enhanced expression of hepcidin and HIF-1α induced by BMP6. CONCLUSIONS: Iron deficiency promoted oxidative stress and apoptosis in HPAECs in hypoxia-induced PH, and enhanced expression of hepcidin regulated by BMP6/BMPR2 signaling may contribute to iron metabolic disorder.
Subject(s)
Bone Morphogenetic Protein Receptors, Type II , Bone Morphogenetic Proteins , Hypertension, Pulmonary , Iron Deficiencies , Animals , Humans , Rats , Endothelial Cells/metabolism , Hepcidins/metabolism , Hypertension, Pulmonary/metabolism , Iron/metabolism , Iron Deficiencies/metabolism , Liver/metabolism , Rats, Sprague-Dawley , Bone Morphogenetic Proteins/metabolism , Bone Morphogenetic Protein Receptors, Type II/metabolismABSTRACT
OBJECTIVE: Sunitinib/sorafenib (SU/SO), dendritic cells (DCs), or DC-cytokine-induced killer (CIK) could significantly prolong progression-free survival (PFS), 3-year overall survival (OS), or 5-year OS for patients with metastatic renal cell carcinoma (mRCC). We retrospectively analyzed the clinical efficacy between SU/SO combined with DC-CIK and SU/SO monotherapy in treating renal cell carcinoma (RCC) patients with metastasis after radical nephrectomy. MATERIALS AND METHODS: All patients (n = 34) with postoperative mRCC in our hospital from January 2009 to January 2014 were received either SU/SO monotherapy (Group 1, n = 15) or in combination with DC-CIK (Group 2, n = 19). A retrospective study was based on the primary endpoint (PFS) and secondary endpoint (OS). RESULTS: At a median follow-up of 19.5 months, in Group 2, as compared with in Group 1, the median PFS was significantly longer (28.0 vs. 11.0 months, P = 0.03). Moreover, the 3-year OS was higher (57.1% vs. 28.6%). The cases of progressive diseases (PDs) and deaths were less in Group 2 than that in Group 1 (PD: 8 vs. 9, deaths: 3 vs. 5); however, the cases of stable diseases were more (11 vs. 6). In addition, the 3-year OS was higher in SU + DC-CIK group than that in SO + DC-CIK group (63.36% vs. 50%). There was no significant difference for PFS between SO + DC-CIK group and SU single agent group. CONCLUSIONS: SU/SO with DC-CIK could significantly prolong the median PFS, improve the 3-year OS rate, prolong the 3-year OS. It is likely to be a new approach for mRCC after radical nephrectomy.