Angiogenesis coupled with osteogenesis in a bone tissue engineering scaffold enhances bone repair in osteoporotic bone defects.

Increased life expectancy has resulted in an increase in osteoporosis incidence worldwide. The coupling of angiogenesis and osteogenesis is indispensable for bone repair. Although traditional Chinese medicine (TCM) exerts therapeutic effects on osteoporosis, TCM-related scaffolds, which focus on the coupling of angiogenesis and osteogenesis, have not yet been used for the treatment of osteoporotic bone defects.Panax notoginsengsaponin (PNS), the active ingredient ofPanax notoginseng, was added to a poly (L-lactic acid) (PLLA) matrix. Osteopractic total flavone (OTF), the active ingredient ofRhizoma Drynariae, was encapsulated in nano-hydroxyapatite/collagen (nHAC) and added to the PLLA matrix. Magnesium (Mg) particles were added to the PLLA matrix to overcome the bioinert character of PLLA and neutralize the acidic byproducts generated by PLLA. In this OTF-PNS/nHAC/Mg/PLLA scaffold, PNS was released faster than OTF. The control group had an empty bone tunnel; scaffolds containing OTF:PNS = 100:0, 50:50, and 0:100 were used as the treatment groups. Scaffold groups promoted new vessel and bone formation, increased the osteoid tissue, and suppressed the osteoclast activity around osteoporotic bone defects. Scaffold groups upregulated the expression levels of angiogenic and osteogenic proteins. Among these scaffolds, the OTF-PNS (50:50) scaffold exhibited a better capacity for osteogenesis than the OTF-PNS (100:0 and 0:100) scaffolds. Activation of the bone morphogenic protein (BMP)-2/BMP receptor (BMPR)-1A/runt-related transcription factor (RUNX)-2signaling pathway may be a possible mechanism for the promotion of osteogenesis. Our study demonstrated that the OTF-PNS/nHAC/Mg/PLLA scaffold could promote osteogenesis via the coupling of angiogenesis and osteogenesis in osteoporotic rats with bone defects, and activating theBMP-2/BMPR1A/RUNX2signaling pathway may be an osteogenesis-related mechanism. However, further experiments are necessary to facilitate its practical application in the treatment of osteoporotic bone defects.

Chinese herbal formula, modified Xianfang Huoming Yin, alleviates the inflammatory proliferation of rat synoviocytes induced by IL-1ß through regulating the migration and differentiation of T lymphocytes.

ETHNOPHARMACOLOGICAL RELEVANCE: Xianfang Huoming Yin (XFH) is a traditional Chinese herbal formula, which has the effect of clearing heat and detoxifying toxins, dispersing swellings, activating blood circulation, and relieving pain. It is usually applied to treat various autoimmune diseases, including Rheumatoid arthritis (RA). AIM OF THE STUDY: The migration of T lymphocytes plays an indispensable role in the pathogenesis of RA. Our previous studies demonstrated that modified Xianfang Huoming Yin (XFHM) could modulate the differentiation of T, B, and NK cells, and contribute to the restoration of immunologic balance. It also could downregulate the production of pro-inflammatory cytokines by regulating the activation of NF-κ B and JAK/STAT signaling pathways in the collagen-induced arthritis mouse model. In this study, we want to investigate whether XFHM has therapeutic effects on the inflammatory proliferation of rat fibroblast-like synovial cells (FLSs) by interfering with the migration of T lymphocytes in vitro experiments. MATERIALS AND METHODS: High performance liquid chromatography-electrospray ionization/mass spectrometer system was used to identify the constituents of the XFHM formula. A co-culture system of rat fibroblast-like synovial cells (RSC-364 cells) and peripheral blood lymphocytes stimulated by interleukin-1 beta (IL-1ß) was used as the cell model. IL-1ß inhibitor (IL-1ßRA) was used as a positive control medicine, and two concentrations (100 µg/mL and 250 µg/mL) of freeze-dried XFHM powder were used as intervention measure. The lymphocyte migration levels were analyzed by the Real-time xCELLigence analysis system after 24 h and 48 h of treatment. The percentage of CD3+CD4+ T cells and CD3+CD8+ T cells, and the apoptosis rate of FLSs were detected by flow cytometry. The morphology of RSC-364 cells was observed by hematoxylin-eosin staining. The protein expression of key factors for T cell differentiation and NF-κ B signaling pathway-related proteins in RSC-364 cells were examined by western-blot analysis. The migration-related cytokines levels of P-selectin, VCAM-1, and ICAM-1 in the supernatant were measured by enzyme-linked immunosorbent assay. RESULTS: Twenty-one different components in XFHM were identified. The migration CI index of T cells was significantly decreased in treatment with XFHM. XFHM also could significantly downregulate the levels r of CD3+CD4+T cells and CD3+CD8+T cells that migrated to the FLSs layer. Further study found that XFHM suppresses the production of P-selectin, VCAM-1, and ICAM-1. Meanwhile, it downregulated the protein levels of T-bet, ROR γ t, IKKα/ß, TRAF2, and NF-κ B p50, upregulated the expression of GATA-3 and alleviated synovial cells inflammation proliferation, contributing to the FLSs apoptosis. CONCLUSION: XFHM could attenuate the inflammation of synovium by inhibiting T lymphocyte cell migration, regulating differentiation of T cells through modulating the activation of the NF-κ B signaling pathway.

The Herbal Combination of Radix astragali, Radix angelicae sinensis, and Caulis lonicerae Regulates the Functions of Type 2 Innate Lymphocytes and Macrophages Contributing to the Resolution of Collagen-Induced Arthritis.

Type 2 innate lymphocytes (ILC2s), promoting inflammation resolution, was a potential target for rheumatoid arthritis (RA) treatment. Our previous studies confirmed that R. astragali and R. angelicae sinensis could intervene in immunologic balance of T lymphocytes. C. lonicerae also have anti-inflammatory therapeutic effects. In this study, the possible molecular mechanisms of the combination of these three herbs for the functions of ILC2s and macrophages contributing to the resolution of collagen-induced arthritis (CIA) were studied. Therefore, we used R. astragali, R. angelicae sinensis, and C. lonicerae as treatment. The synovial inflammation and articular cartilage destruction were alleviated after herbal treatment. The percentages of ILC2s and Tregs increased significantly. The differentiation of Th17 cells and the secretion of IL-17 and IFN-γ significantly decreased. In addition, treatment by the combination of these three herbs could increase the level of anti-inflammatory cytokine IL-4 secreted, active the STAT6 signaling pathway, and then contribute to the transformation of M1 macrophages to M2 phenotype. The combination of the three herbs could promote inflammation resolution of synovial tissue by regulating ILC2s immune response network. The synergistic effects of three drugs were superior to the combination of R. astragali and R. angelicae sinensis or C. lonicerae alone.

EGCG binds intrinsically disordered N-terminal domain of p53 and disrupts p53-MDM2 interaction.

Epigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, µM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 µM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 µM). Large scale atomistic simulations (>100 µs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG's anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.

Inhibition of striatal-enriched protein tyrosine phosphatase by targeting computationally revealed cryptic pockets.

Cryptic pockets, which are not apparent in crystallographic structures, provide promising alternatives to traditional binding sites for drug development. However, identifying cryptic pockets is extremely challenging and the therapeutic potential of cryptic pockets remains unclear. Here, we reported the discovery of novel inhibitors for striatal-enriched protein tyrosine phosphatase (STEP), a potential drug target for multiple neuropsychiatric disorders, based on cryptic pocket detection. By combining the use of molecular dynamics simulations and fragment-centric topographical mapping, we identified transiently open cryptic pockets and identified 12 new STEP inhibition scaffolds through structure-based virtual screening. Site-directed mutagenesis verified the binding of ST3 with the predicted cryptic pockets. Moreover, the most potent and selective inhibitors could modulate the phosphorylation of both ERK1/2 and Pyk2 in PC12 cells.