A Lox/CHOP-10 crosstalk governs osteogenic and adipogenic cell fate by MSCs.

Accelerated marrow adipogenesis has been associated with ageing and osteoporosis and is thought to be because of an imbalance between adipogenic and osteogenic differentiation of mesenchymal stem cell (MSCs). We have previously found that lysyl oxidase (Lox) inhibition disrupts BMP4-induced adipocytic lineage commitment and differentiation of MSCs. In this study, we found that lox inhibition dramatically up-regulates BMP4-induced expression of CCAAT/enhancer binding protein (C/EBP) homologous protein 10 (CHOP-10), which then promotes BMP4-induced osteogenesis of MSCs both in vitro and in vivo. Specifically, Lox inhibition or CHOP-10 up-regulation activated Wnt/ß-catenin signalling to enhance BMP4-induced osteogenesis, with pro-adipogenic p38 MAPK and Smad signalling suppressed. Together, we demonstrate that Lox/CHOP-10 crosstalk regulates BMP4-induced osteogenic and adipogenic fate determination of MSCs, presenting a promising therapeutic target for osteoporosis and other bone diseases.

RhoGDIß Inhibits Bone Morphogenetic Protein 4 (BMP4)-induced Adipocyte Lineage Commitment and Favors Smooth Muscle-like Cell Differentiation.

The integration of signals involved in deciding the fate of mesenchymal stem cells is largely unknown. We used proteomics profiling to identify RhoGDIß, an inhibitor of the small G-protein Rho family, as a component that regulates commitment of C3H10T1/2 mesenchymal stem cells to the adipocyte or smooth muscle cell lineage in response to bone morphogenetic protein 4 (BMP4). RhoGDIß is notably down-regulated during BMP4-induced adipocytic lineage commitment of C3H10T1/2 mesenchymal stem cells, and this involves the cytoskeleton-associated protein lysyl oxidase. Excess RhoGDIß completely prevents BMP4-induced commitment to the adipocyte lineage and simultaneously stimulates smooth muscle cell commitment by suppressing the activation of Rac1. Overexpression of RhoGDIß induces stress fibers of F-actin by a process involving phosphomyosin light chain, indicating that cytoskeletal tension regulated by RhoGDIß contributes to determining adipocyte versus myocyte commitment. Furthermore, the overexpression of RacV12 (constitutively active form of Rac1) totally rescues the inhibition of adipocyte commitment by RhoGDIß, simultaneously preventing formation of the smooth muscle-like phenotype and disrupting the stress fibers in cells overexpressing RhoGDIß. Collectively, these results indicate that RhoGDIß functions as a novel BMP4 signaling target that regulates adipogenesis and myogensis.

The role of pulmonary function in patients with heart failure and preserved ejection fraction: Looking beyond chronic obstructive pulmonary disease.

BACKGROUND: The prognostic value of chronic obstructive pulmonary disease (COPD) as a comorbidity in heart failure has been well documented. However, the role of pulmonary function indices in patients with heart failure and preserved ejection fraction (HFpEF) remains to be elucidated. METHODS: Subjects with HFpEF received pulmonary function tests and echocardiogram. Total lung capacity (TLC), residual volume (RV), forced expiratory flow rate between 25% and 75% of vital capacity (FEF25-75), forced expiratory volume in the 1st second (FEV1), forced vital capacity (FVC), and vital capacity (VC) were measured. Echocardiographic indices, including pulmonary artery systolic pressure (PASP), the ratio of early ventricular filling flow velocity to the septal mitral annulus tissue velocity (E/e'), and left ventricular mass (LVM), were recorded. National Death Registry was linked for the identification of mortality. RESULTS: A total of 1194 patients (72.4±13.2 years, 59% men) were enrolled. PASP, E/e' and LVM were associated with either obstructive (RV/TLC, FEV1 and FEF25-75) or restrictive (VC and TLC) ventilatory indices. During a mean follow-up of 23.0±12.8 months, 182 patients died. Subjects with COPD had a lower survival rate than those without COPD. While VC, FVC, RV/TLC, and FEV1 were all independently associated with all-cause mortality in patients without COPD, only FEF25-75 was predictive of outcomes in those with COPD. CONCLUSIONS: The abnormalities of pulmonary function were related to the cardiac hemodynamics in patients with HFpEF. In addition, these ventilatory indices were independently associated with long-term mortality, especially in those without COPD.

Bis{2-[(E)-benzyl-imino-meth-yl]-4-methyl-phenolato-κN,O}nickel(II).

In the title complex, [Ni(C(15)H(14)NO)(2)], the Ni(II) atom is located on an inversion centre and is coordinated by two O and two N atoms from two symmetry-related bidentate Schiff base ligands in a slightly distorted square-planar geometry. The phenyl and benzene rings in the ligand mol-ecule form a dihedral angle of 72.79 (8)°.

2-Hydr-oxy-N'-(4-isopropyl-cyclo-hexyl-carbon-yl)-3-methyl-benzohydrazide.

The crystal structure of the title compound, C(18)H(26)N(2)O(3), is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds. One of the methyl groups is disordered with occupancies of 0.51 (3):0.49 (3).

Erratum: 2-Hydr-oxy-N'-(4-isopropyl-cyclo-hexyl-carbon-yl)-3-methyl-benzohydrazide. Corrigendum.

The author list in the paper by Shu, Wen, Chen & Lei [Acta Cryst. (2009), E65, o575] is corrected.[This corrects the article DOI: 10.1107/S160053680900556X.].

miR-27 impairs the adipogenic lineage commitment via targeting lysyl oxidase.

OBJECTIVE: The recruitment and commitment of mesenchymal stem cells and their terminal differentiation into adipocytes are the main pathways for increasing adipocyte cell numbers during obesity. Our previous studies have shown that lysyl oxidase (Lox) is upregulated and functions as an essential factor during bone morphogenetic protein 4 (BMP4) -induced C3H10T1/2 cell adipocytic lineage commitment. However, the mechanism of Lox regulation during adipogenic lineage commitment has remained largely unestablished. METHODS: Samples of adipose tissue from humans with different BMI and C57BL/6 mice with a high-fat diet were used to compare microRNA-27 (miR-27) expression level associated with obesity. Taqman assays were used for miR-27 expression detection and Oil Red O staining for adipogenesis analysis. RESULTS: A negative correlation was identified between Lox expression level and miR-27 expression in both BMP4-treated C3H10T1/2 cells and human subcutaneous adipose tissues. A Lox 3' UTR luciferase reporter assay showed that miR-27 directly targeted Lox. Furthermore, overexpression of miR-27 impaired BMP4-induced upregulation of Lox and adipocytic commitment, which could be rescued by overexpression of mature Lox. Conversely, miR-27 inhibition by specific inhibitors increased Lox expression and adipocytic commitment. CONCLUSIONS: Taken together, these results suggest a novel role for miR-27 in repressing adipogenic lineage commitment by targeting Lox.

Gdf6 induces commitment of pluripotent mesenchymal C3H10T1/2 cells to the adipocyte lineage.

Mesenchymal stem cells have the potential to undergo commitment and differentiation into a variety of cell types, including osteoblasts, chondrocytes, myocytes and adipocytes. Growth differentiation factor 6 (Gdf6) is a member of the transforming growth factor ß superfamily. We have examined the potential role of Gdf6 in adipogenesis of mesenchymal stem cells, and found that over-expression of Gdf6 induced commitment of pluripotent mesenchymal C3H10T1/2 cells to the adipocyte lineage. The type I receptor Bmpr1a and the type II receptors Bmpr2 and Acvr2a mediate the Gdf6 signaling pathway. RNAi silencing of Smad4 and p38 MAPK suggested that both Smad and p38 MAPK pathways are involved in this process. The expression of Runx1t1 was down-regulated in committed pre-adipocytes, and forced expression of Runx1t1 blocked the adipocytic commitment. The results demonstrate a role for Gdf6 in adipocytic commitment and differentiation.

Early growth response 2 (Egr2) plays opposing roles in committing C3H10T1/2 stem cells to adipocytes and smooth muscle-like cells.

Early growth response 2 (Egr2) is a zinc-finger transcription factor that acts as an important modulator of a variety of physiological processes, such as cell differentiation, proliferation and apoptosis. Here we showed that Egr2 was downregulated by bone morphogenetic protein (BMP) signaling pathways during the commitment of C3H10T1/2 stem cells to adipocyte lineage. Overexpression of Egr2 completely prevented BMP4-induced adipocyte lineage commitment of C3H10T1/2 stem cells, while simultaneously stimulating early smooth muscle-like differentiation. We also demonstrated that Egr2-induced early smooth muscle-like differentiation is transforming growth factor ß1-independent. Egr2 can activate the transcription of early smooth muscle cell specific genes smooth muscle protein 22α and calponin 1. Together, the results indicated a novel role for Egr2 in repressing adipocyte lineage commitment and promoting early smooth muscle-like cell differentiation.

Induction of EMT-like response by BMP4 via up-regulation of lysyl oxidase is required for adipocyte lineage commitment.

The developmental pathway that gives rise to mature adipocytes involves commitment and terminal differentiation. Our previous findings indicate that BMP4 (bone morphogenetic protein 4) induces nearly complete commitment of C3H10T1/2 pluripotent stem cells to the adipocyte lineage and knockdown of lysyl oxidase (Lox) disrupts this commitment process. Here, we found that an epithelial-mesenchymal transition (EMT)-like response is required for adipocyte lineage commitment and that Lox is indispensable for this process. When C3H10T1/2 cells were treated with BMP4, Vim and Cdh2 showed up-regulated expression while Cdh1 and Ocln were down-regulated along with enhanced cell migration, which are EMT-like responses. Silencing of Lox in BMP4-treated C3H10T1/2 cells induced a mesenchymal-epithelial transition (MET)-like response associated with the repression of mesenchymal markers, induction of epithelial markers and decreased cell migration. Importantly, blocking the EMT-like response by knocking down Cdh2 or over-expression of Cdh1 impairs adipocyte lineage commitment. EMT is regulated by distinct transcription factors such as Snai1, Snai2 and Twist. In this study, we also found that only Twist was down-regulated after Lox silencing in C3H10T1/2 cells treated with BMP4. This study provides new insights into adipocyte lineage commitment.

Effects of matrine and oxymatrine on catalytic activity of cytochrome p450s in rats.

Matrine and oxymatrine are the major bioactive compounds extracted from the root of Sophora flavescens Ait, which have been widely used in traditional Chinese medicines. The objective of the study was to investigate the effects of matrine or oxymatrine on hepatic cytochrome P450 (CYP450) and the underlying molecular mechanisms. Matrine (15, 75 and 150 mg/kg) or oxymatrine (36, 180 and 360 mg/kg) was administered to rats for 14 days and the activities of CYP450 were measured by the quantification of the metabolites from multiple CYP450 probe substrates, using validated liquid chromatography coupled with liquid chromatography-tandem mass spectrometry detection (LC-MS/MS) and high-performance liquid chromatography methods. The mRNA and protein expression levels of CYPs were determined by quantitative real-time reverse-transcription polymerase chain reaction and Western blotting analysis respectively. Interactions between matrine or oxymatrine and human constitutive androstane (CAR), pregnane X receptor were evaluated by means of the reporter gene assay in CV-1 cells. Our study showed that matrine and oxymatrine significantly induced the activity and gene expression of CYP2B1 in a dose-dependent manner; matrine (150 mg/kg) slightly induced the mRNA and protein expression of CYP2E1 and mildly inhibited the mRNA and protein expression of CYP3A1 in rats. Matrine or oxymatrine could activate human CAR and induce the CYP2B reporter construct in CV-1 cells. These results reveal that matrine and oxymatrine can induce the activity and expression of CYP2B1/2 in rats, and the underlying mechanism may be related to the activation of CAR.