Discovery and development of berberine derivatives as stimulants of osteoblast differentiation

A novel berberine derivative targeting adipocyte differentiation to alleviate TNF-α-induced inflammatory effects and insulin resistance in OP9 cells

Inflammation and insulin resistance play important roles in the development and progression of type 2 diabetes mellitus. The enhancement of adipocyte differentiation can improve insulin sensitivity by increasing glucose uptake, improving insulin signaling, and reducing inflammation. However, only a few adipogenic agents have shown clinical success in patients with type 2 diabetes mellitus. The therapeutic potential of berberine in type 2 diabetes mellitus was confirmed in terms of the target gene-disease relationship using a network pharmacology database prior to synthesizing the derivatives. Novel berberine derivatives were synthesized, and compound 3b promoted adipocyte differentiation and improvement of insulin resistance in OP9 cells. Compound 3b significantly increased the expression of key adipogenic markers including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein β (C/EBPβ) and promoted lipid accumulation without cytotoxicity. Furthermore, tumor necrosis factor α (TNF-α)-induced inhibition of adipocyte differentiation and the elevation of inflammatory responses were reversed by compound 3b. Subsequently glucose uptake level through insulin sensitivity improvement was enhanced by compound 3b. Mechanistically, TNF-α activated mitogen-activated protein kinases (MAPKs): ERK, JNK, and p38, whereas compound 3b attenuated phosphorylation of three MAPKs. Finally, in silico molecular docking suggested the possible binding sites of compound 3b on PPARγ. Collectively, the adipogenic and glucose uptake effects of compound 3b were associated with its anti-inflammatory effects and reduced phosphorylation of MAPKs. These findings suggest that the berberine derivative compound 3b may be a potent antidiabetic agent.

Wnt/β-Catenin Signaling Inhibits Osteogenic Differentiation in Human Periodontal Ligament Fibroblasts

The periodontal ligament is a collagenous tissue that is important for maintaining the homeostasis of cementum and alveolar bone. In tendon cells, Wnt/β-catenin signaling has been reported to regulate the expression level of Scleraxis (Scx) and Mohawk Homeobox (Mkx) gene and maintain the tissue homeostasis, while its role in the periodontal ligament is unclear. The aim of this study was to investigate the effects of Wnt/β-catenin signaling induced by Wnt-3a stimulation on the inhibition of osteogenic differentiation of human periodontal ligament fibroblasts (HPLFs). During osteogenic differentiation of HPLFs, they formed bone nodules independently of alkaline phosphatase (ALP) activity. After stimulation of Wnt-3a, the expression of β-catenin increased, and nuclear translocation of β-catenin was observed. These data indicate that Wnt-3a activated Wnt/β-catenin signaling. Furthermore, the stimulation of Wnt-3a inhibited the bone nodule formation and suppressed the expression of osteogenic differentiation-related genes such as Runx2, Osteopontin and Osteocalcin, and upregulated the gene expression of Type-I collagen and Periostin (Postn). Scx may be involved in the suppression of osteogenic differentiation in HPLFs. In conclusion, Wnt/β-catenin signaling may be an important signaling pathway that inhibits the osteogenic differentiation in HPLFs by the upregulation of Scx gene expression and downregulation of osteogenic differentiation-related genes.

Repair calvarial defect of osteoporotic rats by berberine functionalized porous calcium phosphate scaffold

In this article, we propose a simple scheme of using berberine (BBR) to modify porous calcium phosphate ceramics (named PCPC). These BBR molecules regulate the crystallization of hydroxyapatite nanorods on PCPC. We found that these nanorods and the adsorbed BBR changed the interface micro-environment of PCPC by SEM images. The microenvironment of PCPC surface is essential for promoting BMSCs’ proliferation and differentiation. These results demonstrated that PCPC/BBR markedly improved the bone regeneration of osteoporosis rats. Moreover, PCPC/BBR had significantly increased the expression levels of ALP, osteocalcin and bone morphogenetic protein2 and RUNX2 in BMSCs originated from osteoporosis rats.