Axin 1 knockdown inhibits osteoblastic apoptosis induced by Porphyromonas gingivalis lipopolysaccharide

Activation of the transcription factor hypoxia inducible factor‑1α (HIF-1α) is considered critical for the stimulation of osteogenic markers including runt‑related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and osteocalcin, which are closely associated with forkhead boxclassO1 (Foxo1) levels in osteoblasts. The present study explored the associations between HIF‑1α and Foxo1 in the regulation of cell viability, proliferation and apoptosis of osteoblasts. Osteoblasts obtained from children's iliac cancellous bone were used in the present study, which were confirmed by immunofluorescence staining for the osteoblast marker osteocalcin. The results revealed that the levels of reactive oxygen species and apoptosis were markedly increased in cells with knockdown of HIF‑1α. By contrast, these were reduced in response to overexpressed HIF‑1α. In addition, HIF‑1α overexpression significantly stimulated cell viability, which was suppressed by silencing HIF‑1α. HIF‑1α overexpression also significantly increased the transcriptional and translational levels of Foxo1. Conversely, silencing HIF‑1α markedly suppressed the expression levels of Foxo1. Furthermore, silencing HIF‑1α reduced the expression of osteogenic markers, including Runx2, ALP and osteocalcin. Runx2 and ALP expression induced by HIF1α were markedly reversed by Foxo1 small interfering (si)RNA, whereas osteocalcin was not significantly affected by Foxo1 siRNA. Therefore, the cooperation of and interactions between HIF‑1α and Foxo1 may be involved in the regulation of osteoblast markers, and serve a pivotal role in the proliferation and apoptosis of osteoblast. The HIF1α‑induced expression of Runx2 and ALP may be completely dependent on the expression levels of Foxo1, and in turn, osteocalcin may be partially dependent on Foxo1 expression.

Treatment of localized periodontal disease in pregnancy does not reduce the occurrence of preterm birth: results from the Periodontal Infections and Prematurity Study (PIPS)

Evidence for the Failure of Adeno-associated Virus Serotype 5 to Package a Viral Genome ≥8.2 kb

The expression of microRNA-206 (miR-206) is aberrantly induced in steroid-induced avascular necrosis of femoral head (SANFH). Therefore, investigating the function of miR-206 in SANFH and uncovering the functional mechanism associated with the condition will promote the understanding and treatment of the disease. The purpose of the present study was to investigate the pro-osteoclasteogenic effect of miR-206 that occurs through regulation of programmed cell death 4 (PDCD4). The expression of miR-206 and PDCD4 was analyzed in the clinical SANFH specimens. The level of miR-206 and PDCD4 was regulated in human osteoblast lineage hFOB1.19 and the effect of different treatments on cell viability, proliferation, apoptosis and differentiation potential of osteoblasts were analyzed with a Cell Counting kit-8, 5-ethynyl-2′-deoxyuridine staining, flow cytometry and Hoechst staining. The expression of miR-206 was upregulated while PDCD4 was downregulated in the SANFH specimens. Induced expression of miR-206 decreased cell viability and proliferation, while apoptosis was induced. At the molecular level, overexpression of miR-206 inhibited the expression of PDCD4, alkaline phosphatase (ALP) and B-cell lymphoma 2 (Bcl-2), and increased the expression of apoptosis regulator Bcl2-X-associated protein (Bax). Inhibiting the expression of miR-206 increased cell viability and proliferation but had no effect on cell apoptosis, as detected by flow cytometry and Hoechst staining. However, at the molecular level, inhibiting the expression of miR-206 induced expression of PDCD4, ALP and Bcl-2, while it decreased the expression of Bax. Additionally, knockdown of PDCD4 blocked the effect of miR-206 inhibition on hFOB1.19 cells, representing a PDCD4-dependent manner of miR-206 in inducing apoptosis of osteoblasts. Therefore, miR-206 promoted the onset of SANFH by inducing apoptosis and suppressed the proliferation of osteoblasts, which was dependent on the inhibition of PDCD4.

To explore the mechanism of Piezo1 protein in mediating the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) via the Notch signaling pathway. In this study, young permanent teeth extracted from impacted teeth of 8-14-year- old children from January 1, 2016 to January 1, 2018 in the Department of Orthodontic, Beijing Children's Hospital were selected as cell sources. hPDLSCs were extracted by enzymatic digestion. Immunohistochemical staining was used to detect the expression of keratin and vimentin, and flow cytometry was used to identify the markers (CD146 and STRO-1) of hPDLSCs. The construction and screening of Piezo1 siRNA gene interference vector and Piezo1 gene overexpression plasmid were completed. Flexcell 4000T mechanical distraction stress instrument was used to construct hPDLSC cell model in vitro. According to the preliminary results, the experiment was divided into five groups: siRNA interference group, overexpression group, blank control group, stretch stress group, and negative control group. Real time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of Piezo1, Notch1, alkaline phosphatase (ALP), Runt-related transcription factor 2 (Runx2), osteocalcin (OCN), and bone sialoprotein (BSP). Western blot was used to detect the expression of ALP and Runx2. Fluo-3 AM probe was used to detect intracellular calcium content. Vimentin staining of hPDLSCs was positive, and keratin staining was negative. Flow cytometry was used to detect the expression of STRO-1 and CD146, markers of hPDLSC. Empty viral vectors, siRNA-Piezo1 interference sequence, and Piezo1 overexpression vector sequence could be transfected into hPDLSC by lentivirus, and the transfection efficiency was high (approximately 90%). The reverse transcription-polymerase chain reaction (RT-PCR) results showed that there were significant differences in Piezo1 gene levels among the siRNA interference group, overexpression group, blank control group, stretch stress group, and negative control group (F=9.573, P<0.05). The level of Piezo1 in the overexpression group was significantly higher than that in the siRNA interference group (q=3.893, P<0.05). The level of Piezo1 in the stretch stress group was significantly higher than that in the blank control group (q=2.006, P<0.05). The expression of Notch1 and osteogenic genes ALP, Runx2, OCN, and BSP had the same trend. Western blot results showed that there were significant differences in the expression of ALP in the siRNA interference group, overexpression group, blank control group, stretch stress group, and negative control group (F=11.207, P<0.001). The expression level of ALP in the overexpression group was significantly higher than that in the siRNA interference group (q=2.991, P<0.05). The expression of ALP in the stretch stress group was significantly higher than that in the blank control group (q=3.007, P<0.05). The expression of Runx2 protein showed the same trend. The intracellular calcium fluorescence intensity of the overexpression group was significantly higher than that of the siRNA interference group, and the intracellular calcium fluorescence intensity of the stretch stress group was significantly higher than that of the siRNA interference group. Mechanical stretch stress can promote the expression of Piezo1 protein. Ca2+ is the second messenger, activates the Notch1 signaling pathway and the expression of ALP, Runx2, OCN, and BSP; and promotes the osteogenic differentiation of hPDLSC. The siRNA-Piezo1 interfering plasmid can block this process. On the contrary, the overexpression plasmid of Piezo1 can promote the osteogenic differentiation of PDLSCs.

Role of macrophages in LPS-induced osteoblast and PDL cell apoptosis

In this article the review of foreign and domestic literary sources, which are devoted to the actual problem of modern dentistry – the treatment of inflammatory diseases of periodontal tissues: gingivitis and periodontitis are presented. The complex approach to their treatment involves the appointment of a significant amount of pharmacotherapeutic drugs. Therapeutic failures and iatrogenic complications have led to the fact that today the interests of doctors and population to medicinal products significantly increased. The purpose of the study is to analyze the data of scientific literature on the use of plant-based medicinal products for the treatment of periodontal inflammatory diseases over the past 10 years. Materials and methods. Comprehensive and systematic analysis of literature. Review and discussion. The analysis of information sources on the use of plant-based medicinal products in dentistry both independently and in the composition of medical and prophylactic means has established that the modern assortment of plant-based preparations in the pharmaceutical market of Ukraine to a certain extent is limited. The emergence of new plant-based species that have been tested in conditions of experimental pathology and require an evidence-based clinical base is noted. The composition of plant-based preparations used for the treatment of inflammatory periodontal diseases include vitamins, biologically active substances, glycosides, alkaloids, in connection with a wide range of action: antiseptic, anti-inflammatory, regenerating, hemostatic, antioxidative. The data on plant-based preparations that are most often used such as chamomile extracts, calendula, hypericum, plantain, kalanchoe, aloe, eucalyptus, milfoil, nettle, calamus and plant-based species are summarized. The medicinal agents considered are mainly recommended for local treatment of periodontal diseases in the form of dental care means, mouth rinse, gel, chewing gum, herbal liquer. It is known that the complex treatment of periodontal diseases includes a general influence on the body. The properties of green tea with its wide range of actions are investigated. With antioxidant properties, it can be a healthy alternative for controlling destructive changes in periodontal diseases. Attention is drawn to the proposed unique natural complex “Resverazin” due to a wide range of pharmacological action, low toxicity and relative safety. The drug produces antioxidant, anti-inflammatory, immune stimulating, vasodilative, neuroprotective action. Conclusion. Based on the literature analysis, it can be concluded that the accumulated experimental and clinical data on the therapeutic properties of plants prove perspective of their use in the complex treatment of inflammatory periodontal diseases. Future studies are mandatory for further confirmation of the effectiveness of these medicinal plants

Differential effects of secreted frizzled-related proteins (sFRPs) on osteoblastic differentiation of mouse mesenchymal cells and apoptosis of osteoblasts

To investigate the effect of stretch on long non-coding RNA taurine upregulated gene 1 (TUG1)-mediated miR-545-3p/cannbinoida receptor 2 (CNR2) pathway regulating bone regeneration in the distraction area of rats during distraction osteogenesis. Thirty-six 10-week-old male Sprague Dawley rats were randomly divided into 3 groups ( n=12 in each group): group A (femoral fracture+injection of interfering RNA), group B (distraction osteogenesis+injection of interfering RNA), and group C (distraction osteogenesis+injection of TUG1). Groups A and B were injected with 60 μg of interfering RNA at the beginning of incubation period (immediate after operation), the beginning of distraction phase (7 days after operation), and the end of distraction phase (21 days after operation), and group C was injected with 60 μg of synthetic TUG1 in vivo interfering sequence at the same time. The general situation of rats in each group was observed during the experiment. The mineralization of fracture space or distraction area was observed by X-ray films at 21, 35, and 49 days after operation. At 49 days after operation, the samples of the distraction area were taken for HE staining to observe the mineralization, and real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expressions of osteoblast-related genes such as TUG1, miR-545-3p, CNR2, alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). Blood samples were collected from the abdominal aorta of the rats, and the expressions of ALP and C terminal telopeptide of type Ⅰ (CTX-Ⅰ) protein were detected by ELISA assay. The results of X-ray film and HE staining observations showed that osteogenesis in group C was superior to groups A and B at the same time point. The results of qRT-PCR showed that the relative mRNA expressions of TUG1, CNR2, ALP, OCN, and OPN in group C were significantly higher than those in group A and group B, and the relative mRNA expression of miR-545-3p in group C was significantly lower than that in group A and group B ( P<0.05). The relative mRNA expressions of TUG1 and ALP in group B were significantly higher than those in group A, and the relative mRNA expression of miR-545-3p in group B was significantly lower than that in group A ( P<0.05). There was no significant difference in the relative mRNA expressions of CNR2, OCN, and OPN between group A and group B ( P>0.05). The results of ELISA showed that the expressions of ALP and CTX-Ⅰ protein were significantly higher in group C than in group A and group B, and in group B than in group A ( P<0.05). Under the action of stretch, the expression of TUG1 in the femoral distraction area of rats increases, which promotes the expression of CNR2 by inhibiting the expression of miR-545-3P, which is helpful to the mineralization of the extension area and osteogenesis.

Background: Bone fracture is a common medical condition. Evidence suggested that long noncoding RNAs (lncRNAs) could regulate the bio-function in osteoblast. In this study, we explored the role and mechanism of lncRNA X-inactive specific transcript (XIST) on the proliferation, apoptosis, and differentiation of osteoblasts using MC3T3-E1 cells. Methods: Expression of XIST, microRNA-203-3p (miR-203-3p), and zinc finger protein multitype 2 (ZFPM2) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis of MC3T3-E1 cells were measured using the Cell Counting Kit-8 (CCK-8) and the flow cytometry. Western blot was used to measure the expression of cell cycle-related proteins, apoptosis-related proteins, and ZFPM2. Levels of differentiation-related factors were measured by qRT-PCR, western blot, and alkaline phosphatase (ALP) kit. Target interaction between miR-203-3p and XIST or ZFPM2 was predicted through bioinformatics analysis and verified by dual-luciferase reporter, RNA immunoprecipitation (RIP) assay, or RNA pull-down assay. Results: The expression of XIST and ZFPM2 was increased while miR-203-3p was decreased in plasmas and MC3T3-E1 cells. Knockdown of XIST promoted the proliferation, differentiation, but limited apoptosis in MC3T3-E1 cells. . Mechanically, overexpression of XIST could reverse the bio-function of miR-203-3p transfection. Additionally, miR-203-3p inverted a series of bio-functional effects of ZFPM2. Furthermore, anti-miR-203-3p rescued si-XIST-induced downregulation of ZFPM2. Conclusion: Downregulation of lncRNA XIST promoted osteoblast proliferation and differentiation, but limited apoptosis by miR-203-3p/ZFPM2 axis.

The aim of this study was to research the potential mechanism of INHBC and CSF1R in diabetic nephropathy. 30 SD rats were selected and randomly divided into Con group, Sham group, and DN group. In the DN group, intraperitoneal injection of the streptozotocin-citrate solution was conducted to construct the DN model. In the Sham group, intraperitoneal injection of equal citrate solution was conducted. The Con group did not do anything. After successful modeling, blood glucose, insulin, biochemical indexes, and levels of inflammatory cytokines in blood samples were detected. The expression levels of INHBC, CSF1R, apoptosis-related proteins and IGF-1 were detected by Western blot. MRNA expression levels of INHBC, CSF1R, IGF-1 and inflammatory cytokines were detected by qPCR. Compared with the Con group, the expression levels of blood glucose, insulin, biochemical indexes, INHBC, CSF1R, IGF-1, IL-6, TNF-α and Bcl2 increased in the DN group, while the expression levels of IL-10, Caspase 3, Caspase 9, and Bax decreased. INHBC mRNA was positively correlated with IGF-1 mRNA. CSF1R was negatively correlated with Caspase 3, Caspase 9, Bax, and IL-10, and positively correlated with IL-6, TNF-α, and Bcl2. NHBC and CSF1R induced the secretion of IL-6 and TNF-α, inhibited the production of IL-10, inhibited apoptosis of cells, and promoted the proliferation of renal cells during DN disease. Therefore, INHBC and CSF1R can be used as target objects of DN treatment strategies.

Objective To investigate the effects of miR-335-5p on the proliferation and apoptosis of osteoblasts which were exposed to high glucose condition, and explore its possible molecular mechanisms. Methods MC3T3-E1 osteoblasts were divided into four groups: control group(5.5 mmol/L glucose), high glucose group(HG group, 22.0 mmol/L glucose), agomir-335-5p group(transfected with agomir-335-5p and exposed to 22.0 mmol/L glucose), and agomir negative control group(agomir NC group, transfected with agomir negative control and exposed to 22.0 mmol/L glucose), cultured for 7 days. Cell proliferaton, cell apoptosis, expressions of miR-335-5p and dickkopf homolog 1(DKK1) mRNA, protein levels of DKK1 and cysteinyl aspartate-specific proteinase-3(caspase-3) were detected using MTT, flow cytometry, quantitative realtime PCR and western blot, respectively. Results Compared with control group, the expression of miR-335-5p mRNA and cell proliferation in HG group were significantly decreased(P 0.05). The miR-335-5p mRNA expression and cell proliferation in agomir-335-5p group were higher than those in HG group and agomir NC group(P<0.05). However, Cell apoptosis and the protein levels of DKK1 and caspase-3 in agomir-335-5p group were lower than those in HG group(P<0.05). Conclusion High glucose inhibits the proliferation and induce the apoptosis of MC3T3-E1 osteoblast through decreasing the expression of miR-335-5p and subsequently increasing the DKK1 expression. (Chin J Endocrinol Metab, 2015, 31: 712-716) Key words: miR-335-5p; Osteoblast; Proliferation; Apoptosis

Hypoxia Mediates Runt-Related Transcription Factor 2 Expression via Induction of Vascular Endothelial Growth Factor in Periodontal Ligament Stem Cells.

Postmenopausal osteoporosis is a common condition characterized by the increase and activation of osteoclasts. The present study aimed to investigate the effects of extracellular signal-regulated kinase (ERK) 5 (ERK-5) on postmenopausal osteoporosis by regulating the biological behaviors of osteoblasts. Sprague–Dawley (SD) rats were ovariectomized to develop an osteoporosis model. A lentivirus packaging system was employed to generate lentiviruses capable of up- or down-regulating the expression of ERK-5 in ovariectomized rats. The femoral biomechanical properties, bone mineral density (BMD), contents of calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) and bone turnover markers in rats, as well as viability, cycle and apoptosis of osteoblasts and ALP activity in osteoblasts were measured in the ovariectomized rats so as to explore the functional significance of ERK-5 in postmenopausal osteoporosis. The femoral mechanical strength of ovariectomized rats was enhanced by overexpression of ERK-5. Meanwhile femoral BMD, and bone metabolism were increased, and bone turnover normalized in the ovariectomized rats when ERK-5 was overexpressed. Lentivirus-mediated ERK-5 overexpression in osteoblasts was observed to inhibit osteoblast apoptosis, and promote viability, accompanied with increased ALP activity. Taken together, ERK-5 could decelerate osteoblast apoptosis and improve postmenopausal osteoporosis by increasing osteoblast viability. Thus, our study provides further understanding on a promising therapeutic target for postmenopausal osteoporosis.

Human umbilical cord mesenchymal stem cells protect MC3T3-E1 osteoblasts from dexamethasone-induced apoptosis via induction of the Nrf2-ARE signaling pathway