Background— Multilineage developmental capacity of the CD34 + cells, especially into cardiomyocytes and smooth muscle cells (SMCs), is still controversial. In the present study we performed a series of experiments to prove our hypothesis that vasculogenesis and cardiomyogenesis after myocardial infarction (MI) may be dose-dependently enhanced after CD34 + cell transplantation. Methods and Results— Peripheral blood CD34 + cells were isolated from total mononuclear cells of patients with limb ischemia by apheresis after 5-day administration of granulocyte colony-stimulating factor. PBS and 1×10 3 (low), 1×10 5 (mid), or 5×10 5 (high) CD34 + cells were intramyocardially transplanted after ligation of the left anterior descending coronary artery of nude rats. Functional assessments with the use of echocardiography and a microtip conductance catheter at day 28 revealed dose-dependent preservation of left ventricular function by CD34 + cell transplantation. Necropsy examination disclosed dose-dependent augmentation of capillary density and dose-dependent inhibition of left ventricular fibrosis. Immunohistochemistry for human-specific brain natriuretic peptide demonstrated that human cardiomyocytes were dose-dependently observed in ischemic myocardium at day 28 (high, 2480±149; mid, 1860±141; low, 423±9; PBS, 0±0/mm 2 ; P <0.05 for high versus mid and mid versus low). Immunostaining for smooth muscle actin and human leukocyte antigen or Ulex europaeus lectin type 1 also revealed dose-dependent vasculogenesis by endothelial cell and SMC development after CD34 + cell transplantation. Reverse transcriptase–polymerase chain reaction indicated that human-specific gene expression of cardiomyocyte (brain natriuretic peptide, cardiac troponin-I, myosin heavy chain, and Nkx 2.5), SMC (smooth muscle actin and sm22α), and endothelial cell (CD31 and KDR) markers were dose-dependently augmented in MI tissue. Conclusions— Human CD34 + cell transplantation may have significant and dose-dependent potential for vasculogenesis and cardiomyogenesis with functional recovery from MI.

Mesenchymal cells, primarily fibroblasts and myofibroblasts, are the principal matrix-producing cells during pulmonary fibrogenesis. Transforming growth factor (TGF)-beta signaling plays an important role in stimulating the expression of type I collagen of these cells. Bone morphogenetic protein (BMP)-7, a member of the TGF-beta superfamily, has been reported to oppose the fibrogenic activity of TGF-beta1. Here, we have addressed the effects of BMP-7 on the fibrogenic activity of pulmonary myofibroblasts. We first established cell lines from the lungs of transgenic mice harboring the COL1A2 upstream sequence fused to luciferase. They displayed a spindle shape and expressed vimentin and alpha-smooth muscle actin, but not E-cadherin. COL1A2 promoter activity was dose dependently induced by TGF-beta1, which was further augmented by adenoviral overexpression of Smad3, but was downregulated by Smad7. Under the identical condition, adenoviral overexpression of BMP-7 attenuated the TGF-beta1-dependent COL1A2 promoter activity. By immunocytochemistry, the ectopic expression of BMP-7 led to the nuclear localization of phospho-Smad1/5/8 and suppressed that of Smad3. BMP-7 suppressed the expression of mRNAs for COL1A2 and tissue inhibitor of metalloproteinase-2 while increasing those of inhibitors of differentiation (Id) 2 and 3. Ectopic expression of Id2 and Id3 was found to decrease the COL1A2 promoter activity. Finally, BMP-7 and Id2 decreased TGF-beta1-dependent collagen protein secretion. In conclusion, these data demonstrate that BMP-7 antagonizes the TGF-beta1-dependent fibrogenic activity of mouse pulmonary myofibroblastic cells by inducing Id2 and Id3.

Super-elderly HCC patients who are appropriately evaluated and selected might have a favorable prognosis after undergoing hepatic resection.