Multiple Forms of Epidermal α-Fucosidase

Two forms of α-fucosidase from newborn rat epidermis were separated by gel filtration on Sephadex G-150. These enzymes termed, fucosidase I which was eluted in the void volume and fucosidase II (molecular weight approximately 50,000). Both enzymes had pH optima for 4-methylumbelliferyl-α-L-fucoside hydrolysis between 5.5–6.5. Km values for fucosidase I and II with the same substrate were 3.7 × 10−5 and 5.4 × 10−5 M, respectively. Three different forms of new born rat epidermal α-fucosidase were separated by isoelectric focusing. Evidence is present which indicates that the electrophoretic heterogeneity of α-fucosidase is due in part to the binding of sialic acid to the primary gene product

Skeletal myoblast sheet transplantation improves the diastolic function of a pressure-overloaded right heart

ObjectiveThe development of right ventricular dysfunction has become a common problem after surgical repair of complex congenital heart disease. A recent study reported that tissue-engineered skeletal myoblast sheet transplantation improves left ventricular function in patients with dilated and ischemic cardiomyopathy. Therefore myoblast sheet transplantation might also improve ventricular performance in a rat model of a pressure-overloaded right ventricle.MethodsSeven-week-old male Lewis rats underwent pulmonary artery banding. Four weeks after pulmonary artery banding, myoblast sheet transplantation to the right ventricle was performed in the myoblast sheet transplantation group (n = 20), whereas a sham operation was performed in the sham group (n = 20).ResultsFour weeks after performing the procedure, a hemodynamic assessment with a pressure–volume loop showed a compensatory increase in systolic function in both groups. However, only the myoblast sheet transplantation group showed a significant improvement in the diastolic function: end-diastolic pressure (sham vs myoblast sheet transplantation, 10.3 ± 3.1 vs 5.0 ± 3.7 mm Hg; P < .001), time constant of isovolumic relaxation (11.1 ± 2.5 vs 7.6 ± 1.2 ms, P < .001), and end-diastolic pressure–volume relationship (16.1 ± 4.5 vs 7.6 ± 2.4/mL, P < .005). The right ventricular weight and cell size similarly increased in both groups. A histologic assessment demonstrated significantly suppressed ventricular fibrosis and increased capillary density in the myoblast sheet transplantation group in comparison with those in the sham group. Reverse transcription–polymerase chain reaction demonstrated an increased myocardial gene expression of hepatocyte growth factor and vascular endothelial growth factor in the myoblast sheet transplantation group but not in the sham group.ConclusionsSkeletal myoblast sheet transplantation improved the diastolic dysfunction and suppressed ventricular fibrosis with increased capillary density in a rat model of a pressure-overloaded right ventricle. This method might become a novel strategy for the myocardial regeneration of right ventricular failure in patients with congenital heart disease

Farnesyl pyrophosphate regulates adipocyte functions as an endogenous PPARγ agonist

The cholesterol biosynthetic pathway produces not only sterols but also non-sterol mevalonate metabolites involved in isoprenoid synthesis. Mevalonate metabolites affect transcriptional and post-transcriptional events that in turn affect various biological processes including energy metabolism. In the present study, we examine whether mevalonate metabolites activate PPARγ (peroxisome-proliferator-activated receptor γ), a ligand-dependent transcription factor playing a central role in adipocyte differentiation. In the luciferase reporter assay using both GAL4 chimaera and full-length PPARγ systems, a mevalonate metabolite, FPP (farnesyl pyrophosphate), which is the precursor of almost all isoprenoids and is positioned at branch points leading to the synthesis of other longer-chain isoprenoids, activated PPARγ in a dose-dependent manner. FPP induced the in vitro binding of a co-activator, SRC-1 (steroid receptor co-activator-1), to GST (glutathione transferase)–PPARγ. Direct binding of FPP to PPARγ was also indicated by docking simulation studies. Moreover, the addition of FPP up-regulated the mRNA expression levels of PPARγ target genes during adipocyte differentiation induction. In the presence of lovastatin, an HMG-CoA (3-hydroxy-3-methylglutaryl-CoA) reductase inhibitor, both intracellular FPP levels and PPARγ-target gene expressions were decreased. In contrast, the increase in intracellular FPP level after the addition of zaragozic acid, a squalene synthase inhibitor, induced PPARγ-target gene expression. The addition of FPP and zaragozic acid promotes lipid accumulation during adipocyte differentiation. These findings indicated that FPP might function as an endogenous PPARγ agonist and regulate gene expression in adipocytes

Enhanced Therapeutic Effects of Human iPS Cell Derived-Cardiomyocyte by Combined Cell-Sheets with Omental Flap Technique in Porcine Ischemic Cardiomyopathy Model

Transplant of human induced pluripotent stem cell derived cardiomyocytes (hiPS-CMs) cell-sheet is a promising approach for treating ischemic cardiomyopathy (ICM). However, poor blood supply to the transplanted cell-sheet is a concern related to the effectiveness and durability of the treatment. Herein, we hypothesized that the combined the omentum flap might enhance survival and the therapeutic effects of hiPS-CM cell-sheet transplant for ICM treatment. Treatment by Wnt signaling molecules in hiPS cells produced hiPS-CMs, which were magnetically labeled by superparamagnetic iron oxide (SPIO), followed by culture in the thermoresponsive dishes to generate hiPS-CMs cell-sheets. A porcine ICM model included 4 groups; sham operation, omentum flap only, cell-sheet only, or combination therapy. Ejection fraction (EF) was significantly greater in the cell-sheet only and combination group compared to the other groups during the follow-up period. At 3 months, the EF of the combination group was significantly greater than that of the cell-sheet only group. Consistently, the survival rate of the SPIO-labeled hiPS-CMs, as assessed by MRI, was significantly greater in the combination group than in the cell-sheet only group. This cell delivery system would be useful in optimizing the hiPS-CM cell-sheet transplant for treating severe heart failure