Cudratricusxanthone A (CTXA) is a natural bioactive compound extracted from the roots of Cudrania tricuspidata Bureau and has been shown to possess anti-inflammatory, anti-proliferative, and hepatoprotective activities. However, at present, anti-adipogenic and anti-inflammatory effects of CTXA on adipocytes remain unclear. In this study, we investigated the effects of CTXA on lipid accumulation and expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, two known inflammatory enzymes, in 3T3-L1 preadipocytes. Strikingly, CTXA at 10 µM markedly inhibited lipid accumulation and reduced triglyceride (TG) content during 3T3-L1 preadipocyte differentiation with no cytotoxicity. On mechanistic levels, CTXA at 10 µM suppressed not only expression levels of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), and perilipin A, but also phosphorylation levels of signal transducer and activator of transcription-3 (STAT-3) and STAT-5 during 3T3-L1 preadipocyte differentiation. In addition, CTXA at 10 µM up-regulated phosphorylation levels of cAMP-activated protein kinase (AMPK) while down-regulating expression and phosphorylation levels of acetyl-CoA carboxylase (ACC) during 3T3-L1 preadipocyte differentiation. Moreover, CTXA at 10 µM greatly attenuated tumor necrosis factor (TNF)-α-induced expression of iNOS, but not COX-2, in 3T3-L1 preadipocytes. These results collectively demonstrate that CTXA has strong anti-adipogenic and anti-inflammatory effects on 3T3-L1 cells through control of the expression and phosphorylation levels of C/EBP-α, PPAR-γ, FAS, ACC, perilipin A, STAT-3/5, AMPK, and iNOS.

In the developing nervous system, the axons of newly generated neurons extend toward destination targets following an exquisitely designed program. Axon guidance molecules are critical for neuronal pathfinding because they regulate both directionality and growth pace. However, little is known about the molecular mechanism that coordinates proper axonal extension and turning. Here, we show that Metastasis Suppressor 1 (Mtss1), a membrane protrusion protein, was a molecular facilitator ensuring axonal extension while sensitizing axons to Semaphorin 3E (Sema3E)-Plexin-D1 repulsive guidance cue. We demonstrate that Sema3E-Plexin-D1 signaling regulated Mtss1 expression in projecting striatonigral neurons. Mtss1 in turn induced Plexin-D1 localization to the growth cone where it signaled a repulsive cue to Sema3E. Moreover, Mtss1 was important for neurite extension independent of Sema3E. Ablation of Mtss1 expression reduced growth cone collapse and neurite extension in cultured neurons. Mtss1-knockout mice exhibited fewer striatonigral projections and irregular axonal routes, and these defects were recapitulated in Plxnd1-knockout mice. These findings demonstrate that repulsive axon guidance signaling activates an autoregulatory program to coordinate both axonal extension and steering during neuronal pathfinding.

Salvianolic acid B (Sal B) is one of the most active hydrophilic compounds extracted from Salvia miltiorrhiza root. Previous in vitro and in vivo studies demonstrate the ability of Sal B to modulate adipocyte differentiation. However, the lipid-modulating effect and mechanism of Sal B in adipocytes remain controversial. Here we investigated the regulatory effect and mode of action of Sal B on lipid accumulation in 3T3-L1 preadipocyte differentiation. Lipid droplet (LD) accumulation and triglyceride (TG) content during 3T3-L1 preadipocyte differentiation were measured by Oil Red O staining and AdipoRed assay. The growth inhibition during 3T3-L1 preadipocyte differentiation was measured by cell count analysis. Western blotting and real-time qPCR analysis were utilized to determine the protein and mRNA expression in the preadipocyte differentiation. Notably, in 3T3-L1 preadipocyte differentiation, treatment with Sal B at 100 M led to a marked decrease in LD accumulation and TG content without influencing cell growth. Sal B treatment (100 M) further reduced the expression and phosphorylation levels of adipogenic transcription factors, including CCAAT/enhancer-binding protein- (C/EBP-), peroxisome proliferator-activated receptor-gamma (PPAR)-, and signal transducer and activator of transcription (STAT)-3/5. Treatment with Sal B (100 M) also reduced the expression and phosphorylation levels of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), two lipogenic enzymes and perilipin A, an LD-binding and stabilizing protein. These results collectively demonstrate that Sal B at 100 M strongly inhibits lipid accumulation in 3T3-L1 preadipocyte differentiation, mediated through regulation of the expression and phosphorylation levels of C/EBP-, PPAR-, STAT-3/5, FAS, ACC, and perilipin.

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