Osteoblast and adipocyte are differentiated from mesenchymal stem cells and dysregulation of the differentiation might result in disease, such as osteoporosis and diabetes. To find small compounds that induce osteoblast differentiation, we screened an in-house natural compounds library with mouse preosteoblastic MC3T3-E1 cells using alkaline phosphatase (ALP) expression as an early osteoblast marker. We found that phenazine-1-carboxylic acid (PCA), one of the major phenazine derivatives produced by Pseudomonas, induced osteoblast differentiation in the cells at micromolar concentrations. PCA acted synergistically with an agonist of hedgehog signaling in inducing ALP activity in the cells. We also found that 2-hydroxy-PCA (2H-PCA) induced osteoblast differentiation in the cells but 2-methoxy-PCA and 1-hydroxy-phenazine did not. Unexpectedly, treatment of mouse pluripotent mesenchymal C3H10T1/2 cells with PCA or 2H-PCA induced an obvious morphological change. Oil Red O staining and real-time reverse-transcription PCR analysis revealed that PCA induced not osteoblast differentiation but adipocyte differentiation in C3H10T1/2 cells. These compounds could allow us to investigate the mechanism of osteoblast and adipocyte differentiation in the two model cell systems through a chemical biology approach.

中文翻译：

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吩嗪羧酸及其衍生物在成骨细胞前MC3T3-E1细胞中诱导成骨细胞分化，但在多能间充质C3H10T1 / 2细胞中诱导脂肪细胞分化。

成骨细胞和脂肪细胞与间充质干细胞分化，分化失调可能导致疾病，例如骨质疏松症和糖尿病。为了找到诱导成骨细胞分化的小化合物，我们使用碱性磷酸酶（ALP）表达作为早期成骨细胞标记物，筛选了小鼠成骨前成骨细胞MC3T3-E1细胞的内部天然化合物库。我们发现，由假单胞菌产生的主要吩嗪衍生物之一吩嗪-1-羧酸（PCA）在微摩尔浓度下诱导细胞中的成骨细胞分化。PCA与刺猬蛋白信号传导激动剂具有协同作用，可诱导细胞中的ALP活性。我们还发现2-羟基-PCA（2H-PCA）诱导细胞中的成骨细胞分化，但是2-甲氧基-PCA和1-羟基-吩嗪却没有。不料，PCA或2H-PCA对小鼠多能间充质C3H10T1 / 2细胞的治疗引起明显的形态学改变。油红O染色和实时逆转录PCR分析表明，PCA不会诱导C3H10T1 / 2细胞分化为成骨细胞，而是诱导脂肪细胞分化。这些化合物可以使我们通过化学生物学方法研究两个模型细胞系统中成骨细胞和脂肪细胞分化的机制。