OBJECTIVEThis study aimed to explore the effect of the up-regulation of Notch1 on osteoclastogenesis induced to osteoclasts by receptor activator for nuclear factor-kappaB ligand (RANKL) and macrophage colony-stimulating factors (MCSF) in vitro.

METHODSThe bone marrow stem cells (BMSCs) of Rosa(-notch1) mice were cultured and induced to osteoclasts by RANKL and MCSF. The BMSCs were transfected with the Ad-Cre-green fluorescent protein (GFP) virus or Ad-GFP virus. Total RNA from cells was extracted, and the gene expression levels of Notch1, Notch2, Notch3, Notch4, Deltal, Delta3, Delta4, Jagged1, Hes1, and tartrate resistant acid phosphatase (TRAP) were detected at the defined stage by reverse transcription-polymerase chain reaction (RT-PCR). Osteoclast formation was analyzed by TRAP assay.

RESULTSThe number of TRAP-positive multinuclear cells of the experimental group significantly decreased compared with that of the control group. The mRNA expression levels of Notch1, Notch3, Jagged1, Delta3, and Hesl of the experimental group were significantly higher than those of the control group, whereas the TRAP mRNA expression of the experimental group was significantly lower than that of the control group (P<0.05).

CONCLUSIONUp-regulation of Notch1 inhibit osteoclastogenesis of BMSCs induced by RANKL and MCSF in vitro.

Animals ; Cell Differentiation ; Cell Line ; In Vitro Techniques ; Macrophage Colony-Stimulating Factor ; Mice ; Osteoclasts ; RANK Ligand ; Receptor Activator of Nuclear Factor-kappa B ; Receptor, Notch1 ; metabolism ; Receptor, Notch2 ; Up-Regulation ; physiology

Objective To investigate the feasibility of using anti-sense RNA against classⅡmajor histocompatibility complex(MHCⅡ)transactivator(CⅡTA),which might regulate MHCⅡexpression,to suppress the relative immune response.Methods Stable transfectants of dermal fibroblasts with pDarⅡ(pDarⅡ-D)were tested for the expression of classic MHCⅡ(HLA-DR,-DP,-DQ)antigens induced with recombinant human interferon-gamma(IFN-?).mRNA abundance of CⅡTA,and classic MHCⅡwas mea-sured by RT-PCR.IL-2mRNA expressed in T cells,stimulated by transfected dermal fibroblasts,was de-termined by mixed lymphocyte reaction.Results When induced with IFN-?,the expression of HLA-DR and-DP antigens on pDarⅡ-D was reduced by95.63%and87.89%,respectively.Meanwhile,the mRNA contents of CⅡTA and classic MHCⅡwere decreased significantly(P

Ischemic stroke is one of the leading causes of death and disability worldwide. In Han dynasty， HUA Tuo proposed the original preventive medicine idea that "with good blood circulation， the disease cannot be born"， which opened a broad space for the cross-research of blood-related mechanical factors and pharmacology. In the pathogenesis of ischemic stroke， mechanical factors comprehensively affect the function and crosstalk of platelets and endothelial cells. In recent years， as the well-known effects on thrombosis and stroke， more attention has been paid to hemodynamic factors as the participants involved in pathological mechanisms and potential therapeutic targets of ischemic stroke. The mechanical force ion channel Piezo1 widely exists on the surface of many types of cells. Besides being regulated by chemical and endogenous substances， Piezo1 responds to different mechanical conditions， regulates the opening and closing of channels， and activates different downstream signaling pathways. Piezo1 is now regarded as an important connection between mechanical and biochemical signals. A variety of Chinese medicine can affect the activity of Piezo1 protein， which may prevent and treat thrombotic diseases such as ischemic stroke through Piezo1 protein. In this paper， the effects of Piezo1 protein on the physiological and pathological functions of endothelial cells and platelet under different mechanical conditions and the role of Piezo1 in the process of thrombosis were reviewed， as well as the effects of Chinese medicine， chemical medicine， and endogenous substances targeting Piezo1 channel. These could provide new ideas for further exploring the mechanisms of Chinese medicines in activating blood circulation， developing new drugs， and deepening biomechanical-pharmacology research.

The biomolecular mechanisms that regulate tooth root development and odontoblast differentiation are poorly understood. We found that Atp6i deficient mice (Atp6i^-/-) arrested tooth root formation, indicated by truncated Hertwig's epithelial root sheath (HERS) progression. Furthermore, Atp6i deficiency significantly reduced the proliferation and differentiation of radicular odontogenic cells responsible for root formation. Atp6i^-/- mice had largely decreased expression of odontoblast differentiation marker gene expression profiles (Col1a1, Nfic, Dspp, and Osx) in the alveolar bone. Atp6i^-/- mice sample RNA-seq analysis results showed decreased expression levels of odontoblast markers. Additionally, there was a significant reduction in Smad2/3 activation, inhibiting transforming growth factor-β (TGF-β) signaling in Atp6i^-/- odontoblasts. Through treating pulp precursor cells with Atp6i^-/- or wild-type OC bone resorption-conditioned medium, we found the latter medium to promote odontoblast differentiation, as shown by increased odontoblast differentiation marker genes expression (Nfic, Dspp, Osx, and Runx2). This increased expression was significantly blocked by anti-TGF-β1 antibody neutralization, whereas odontoblast differentiation and Smad2/3 activation were significantly attenuated by Atp6i^-/- OC conditioned medium. Importantly, ectopic TGF-β1 partially rescued root development and root dentin deposition of Atp6i^-/- mice tooth germs were transplanted under mouse kidney capsules. Collectively, our novel data shows that the prevention of TGF-β1 release from the alveolar bone matrix due to OC dysfunction may lead to osteopetrosis-associated root formation via impaired radicular odontoblast differentiation. As such, this study uncovers TGF-β1 /Smad2/3 as a key signaling pathway regulating odontoblast differentiation and tooth root formation and may contribute to future therapeutic approaches to tooth root regeneration.
Female ; Animals ; Mice ; Transforming Growth Factor beta1 ; Odontoblasts ; Culture Media, Conditioned ; Cell Differentiation ; Signal Transduction ; Disease Models, Animal ; Tooth Root