Myeloid-derived growth factor regulates high glucose-mediated apoptosis of gingival fibroblasts and induce AKT pathway activation and nuclear factor κB pathway inhibition.

Background: /purpose: Periodontal disease is a chronic inflammatory disease that occurs in the tissues that support and attach teeth. There is considerable evidence of a relationship between diabetes and periodontal disease. Emerging studies have reported that myeloid-derived growth factor (MYDGF) can inhibit apoptosis and inflammation. The purpose of this study was to investigate whether MYDGF mediates the role of hyperglycemia in fibroblasts in periodontitis tissues. Materials and methods: Fibroblasts were isolated and cultured from normal gums. Gene expression levels were detected by RT-PCR. The protein level was detected by western blotting. Cell viability was determined by MTT assay. To investigate the role of MYDGF, the plasmid was transfected into fibroblasts. The expression levels of cytokines were determined by ELISA. Results: High glucose can down-regulate the expression of MYDGF in human gingival fibroblasts in a time-dependent manner, and decrease the fibroblast activity. SOD level was decreased and MDA level was increased in gingival fibroblasts by high glucose. High glucose up-regulates pro-apoptotic indicator Bax, down-regulates anti-apototic indicator Bcl-2, and increased endoplasmic reticulum stress related indicators Nox 2, GRP78, ATF6, and PERK. In addition, high glucose increased TNF-α, IL-1ß, IL-8 and CXCL1 protein levels in fibroblasts. Our study also found that high glucose inhibits the AKT signaling pathway and activates the nuclear factor κB (NF-κB) pathway. Interestingly, overexpression of MYDGF reversed these effects. Conclusion: MYDGF is down-regulated in gingival fibroblasts induced by high glucose. Overexpression of MYDGF inhibits apoptosis induced by high glucose, inhibits oxidative stress and cytokine secretion of gingival fibroblasts induced by high glucose, and induces AKT pathway activation and NF-κB pathway inhibition.

Isoimperatorin alleviates lipopolysaccharide-induced periodontitis by downregulating ERK1/2 and NF-κB pathways.

Chronic periodontitis is an inflammatory disease characterized by inflammation of the soft tissues of the gums. To combat this disease, more effective drugs are still needed to identify and develop. Isoimperatorin is a kind of a natural compound, which has anti-inflammatory, analgesic, antitumor, antivirus, and other pharmacological effects. However, its possible effects on the progression of chronic periodontitis are still unclear. In this study, we used human periodontal membrane fibroblasts (hPDLCs), human bone marrow-derived macrophages, and found that isoimperatorin reduced hPDLCs viability. In addition, isoimperatorin alleviated the oxidative stress of periodontal membrane cells. Isoimperatorin reduced proinflammatory factor secretion and receptor activator for nuclear factor-κB ligand-induced osteoclast differentiation in periodontal membrane cells. Further, isoimperatorin inhibited the activation of ERK1/2 and nuclear factor-κB pathways. We, therefore, thought isoimperatorin could serve as a promising drug for the treatment of this disease.

The effects of hyperglycemia on the biological behavior of human gingival fibroblasts on a titanium surface.

BACKGROUND: It is well known that diabetes mellitus is one of the high-risk factors for periodontitis and also for the failure of implant restorations. Usually, the success of an implant restoration depends on both the good osseointegration and the stable soft tissue interface on the implant neck. A good gingival interface of the implant neck is the barrier that enables implant to resist oral microorganisms and the site of initiation of peri-implantitis. This study sought to investigate the effects of hyperglycemia on the attachment and proliferation of human gingival fibroblasts (HGFs) on pure titanium surfaces. METHODS: HGFs were cultured in cell culture mediums with different glucose concentrations (i.e., 5.5, 8. 8, 10, and 15 mmol/L) for 7 d and seeded on pure titanium surfaces. The cells that were seeded on the titanium surfaces had been cultured in cell culture mediums with different glucose concentrations for 3 and 7 d. The attached HGFs on the titanium surfaces were counted for all groups using a blood cell counting plate, and the results were statistically analyzed. The morphologies of the attached HGFs on the titanium surfaces were observed for all the groups using a scanning electronic microscope. RESULTS: As the glucose concentrations increased, the number of attached HGFs on the titanium surfaces decreased. The numbers of attached cells in Groups A and B 7 d after being seeded on the titanium surfaces were more than those 3 d after being seeded (P<0.05). The numbers of attached cells in Groups C and D 3 d after being seeded on the titanium were more than those 7 d after being seeded (P<0.05). The scanning electronic microscope showed that the attached cells in Groups A and B proliferated well, and most cells grew one on top of another. Conversely, the attached cells in Groups C and D proliferated sparsely and the cell morphologies were not good. CONCLUSIONS: The attachment and proliferation of HGFs on pure titanium surfaces were inhibited by increases in glucose concentrations, and the inhibition was further enhanced by the passage of time.

Triple Negative Breast Cancer Depends on Sphingosine Kinase 1 (SphK1)/Sphingosine-1-Phosphate (S1P)/Sphingosine 1-Phosphate Receptor 3 (S1PR3)/Notch Signaling for Metastasis.

BACKGROUND Triple negative breast cancer (TNBC) has a more aggressive recurrence. Previous reports have demonstrated that sphingosine kinase 1 (SphK1) is a crucial regulator of breast cancer progression. However, the correlation of SphK1 with clinical prognosis has been poorly investigated. Thus, we aimed to elaborate the role of SphK1 in TNBC metastasis. MATERIAL AND METHODS We first determined the level of SphK1 in breast cancer tissue samples and breast cancer cells. Furthermore, the expression of HER2 and phosphor-SphK1 (pSphK1) in human breast cancer tissue samples was determined by immunohistochemical analysis. Associations between SphK1 and clinical parameters of tumors were analyzed. The activity of SphK1 was measured by fluorescence analysis. Extracellular sphingosine-1-phosphate (S1P) was detected using an ELISA kit. Associations between SphK1 and metastasis potential were analyzed by Transwell assay. RESULTS Levels of SphK1 in TNBC patients were significantly higher than levels in other patients with other breast tumors. The expression of SphK1 was positively correlated with poor overall survival (OS) and progression-free survival (PFS), as well as poor response to 5-FU and doxorubicin. The depression of SphK1 thus could repress the Notch signaling pathway, reduce migration, and invasion of TNBC cells in vivo and in vitro. Furthermore, silencing of SphK1 by Ad-SPHK1-siRNA or SphK1 inhibitor PF543 sensitized TNBCs to 5-FU and doxorubicin. Our results also indicated that SphK1 inhibition could effectively counteracts tumors metastasis via Notch signaling pathways, indicating a potentially anti-tumor strategy in TNBC. CONCLUSIONS We found that elevated levels of pSphK1 were positive correlation with high expression of S1P, which in turn promoted metastasis of TNBC through S1P/S1PR3/Notch signaling pathway.