The Osteogenic Function of Danggui Buxue Tang, a Herbal Decoction Containing Astragali Radix and Angelicae Sinensis Radix, Is Optimized by Boiling the Two Herbs Together: Signaling Analyses Revealed by Systems Biology

The therapeutic efficacy of a herbal mixture, being multi-target, multi-function and multi-pathway, is the niche of traditional Chinese medicine (TCM). Systems biology can dissect the network of signaling mechanisms in a complex biological system. In preparing TCM decoctions, the boiling of herbs together in water is a common practice; however, the rationale of this specific preparation has not been fully revealed. An approach of mass-spectrometry-based multi-omics was employed to examine the profiles of the cellular pathways, so as to understand the pharmacological efficacy of Danggui Buxue Tang (DBT), a Chinese herbal mixture containing Astragali Radix and Angelicae Sinensis Radix, in cultured rat osteoblasts and mesenchymal stem cells. The results, generated from omics analyses, were compared from DBT-treated osteoblasts to those of treating the herbal extract by simple mixing of extracts from Astragali Radix and Angelicae Sinensis Radix, i.e., herbal mixture without boiling together. The signaling pathways responsible for energy metabolism and amino acid metabolism showed distinct activation, as triggered by DBT, in contrast to simple mixing of two herbal extracts. The result supports that boiling the herbs together is designed to maximize the osteoblastic function of DBT, such as in energy and lipid metabolism. This harmony of TCM formulation, by having interactive functions of two herbs during preparation, is being illustrated. The systems biology approach provides new and essential insights into the synergy of herbal preparation. Well-defined multiple targets and multiple pathways in different levels of omics are the key to modernizing TCM.

Genistein Triggers Translocation of Estrogen Receptor-Alpha in Mitochondria to Induce Expressions of ATP Synthesis-Associated Genes and Improves Energy Production and Osteoblast Maturation

Our previous study showed that estrogen can induce mitochondrial adenosine triphosphate (ATP) synthesis-associated gene expressions and osteoblast maturation. Genistein, a phytoestrogenic isoflavone that is widely found in various foods and traditional herb products, is beneficial for osteogenesis by selectively triggering estrogen receptor alpha (ER[Formula: see text] expression. In this study, we further investigated the mechanisms of genistein-induced energy production and osteoblast activation. Exposure of rat calvarial osteoblasts and human U-2 OS cells to genistein triggered osteoblast activation without affecting cell survival. Treatment with genistein time-dependently induced ER[Formula: see text] mRNA and protein expressions in rat calvarial osteoblasts. Analyses by confocal microscopy and immunoblotting showed that genistein stimulated translocation of ER[Formula: see text] from the cytoplasm to mitochondria. Subsequently, expressions of mitochondrial cytochrome c oxidase (COX) I and II mRNAs and proteins in primary rat osteoblasts were induced after exposure to genistein. Knocking-down ER[Formula: see text] concurrently inhibited genistein-induced COX I and II mRNA expressions. In addition, mitochondrial complex enzyme activities, the mitochondrial membrane potential, and cellular ATP levels in rat calvarial osteoblasts were time-dependently augmented by genistein. Suppressing ER[Formula: see text] expression instantaneously lowered genistein-induced enhancements of mitochondrial energy production and osteoblast activation. Effects of genistein on ER[Formula: see text] translocation, COX I and II mRNA expressions, ATP synthesis, and osteoblast activation were further confirmed in human U-2 OS cells. This study showed that genistein can stimulate energy production and consequent osteoblast activation via inducing ER[Formula: see text]-mediated mitochondrial ATP synthesis-linked gene expressions.

Surface-Dependent Osteoblasts Response to TiO2 Nanotubes of Different Crystallinity

One of the major challenges of implantology is to design nanoscale modifications of titanium implant surfaces inducing osseointegration. The aim of this study was to investigate the behavior of rat osteoblasts cultured on anodized TiO2 nanotubes of different crystallinity (amorphous and anatase phase) up to 24 days. TiO2 nanotubes were fabricated on VT1–0 titanium foil via a two-step anodization at 20 V using NH4F as an electrolyte. Anatase-phase samples were prepared by heat treatment at 500 °C for 1 h. VT1–0 samples with flat surfaces were used as controls. Primary rat osteoblasts were seeded over experimental surfaces for several incubation times. Scanning electron microscopy (SEM) was used to analyze tested surfaces and cell morphology. Cell adhesion and proliferation were investigated by cell counting. Osteogenic differentiation of cells was evaluated by qPCR of runt-related transcription factor 2 (RUNX2), osteopontin (OPN), integrin binding sialoprotein (IBSP), alkaline phosphatase (ALP) and osteocalcin (OCN). Cell adhesion and proliferation, cell morphology and the expression of osteogenic markers were affected by TiO2 nanotube layered substrates of amorphous and anatase crystallinity. In comparison with flat titanium, along with increased cell adhesion and cell growth a large portion of osteoblasts grown on the both nanostructured surfaces exhibited an osteocyte-like morphology as early as 48 h of culture. Moreover, the expression of all tested osteogenic markers in cells cultured on amorphous and anatase TiO2 nanotubes was upregulated at least at one of the analyzed time points. To summarize, we demonstrated that amorphous and anodized TiO2 layered substrates are highly biocompatible with rat osteoblasts and that the surface modification with about 1500 nm length nanotubes of 35 ± 4 (amorphous phase) and 41 ± 8 nm (anatase phase) in diameter is sufficient to induce their osteogenic differentiation. Such results are significant to the engineering of coating strategies for orthopedic implants aimed to establish a more efficient bone to implant contact and enhance bone repair.

Long non-coding RNA MEG3 silencing and microRNA-214 restoration elevate osteoprotegerin expression to ameliorate osteoporosis by limiting TXNIP

BackgroundLong non-coding RNAs (LncRNAs) have been found to regulate innumerable diseases, yet the role of lncRNA MEG3 in osteoporosis (OP) has rarely been discussed. Here, we intend to probe into the mechanism of MEG3 on OP development by modulating microRNA-214 (miR-214) and thioredoxin-interacting protein (TXNIP)MethodsRat models of OP were established. MEG3, miR-214, and TXNIP mRNA expression in rat femoral tissues was detected, along with TXNIP, PCNA, cyclin D1, OCN, RUNX2, Osteolix, OPG, and PANKL protein expression. Ca, P and ALP contents in rat blood samples were also determined. Primary osteoblasts were isolated and cultured. Viability, COL-I, COL-II and COL-Χ contents, ALP content and activity, and mineralized nodule area of rat osteoblasts in each group were further detected.ResultsMEG3 and TXNIP were overexpressed while miR-214 was underexpressed in femoral tissues of OP rats. MEG3 silencing and miR-214 overexpression increased BMD, BV/TV, Tb.N, Tb.Th, the number of osteoblasts, collagen area and OPG expression, and downregulated PANKL of femoral tissues in OP rats. MEG3 silencing and miR-214 overexpression elevated Ca and P contents and reduced ALP content in OP rats’ blood, elevated viability, differentiation ability, COL-I and COL-Χ contents and ALP activity, and abated COL-II content of osteoblasts. MEG3 specifically bound to miR-214 to regulate TXNIP.ConclusionCollectively, we demonstrated that MEG3 silencing and miR-214 overexpression promote proliferation and differentiation of osteoblasts in OP by downregulating TXNIP, which further improves OP.