Thymosin Beta-4 Suppresses Osteoclastic Differentiation and Inflammatory Responses in Human Periodontal Ligament Cells

The role of wnt signaling in diabetes-induced osteoporosis

Osteoporosis, a chronic complication of diabetes mellitus, is characterized by a reduction in bone mass, destruction of bone microarchitecture, decreased bone strength, and increased bone fragility. Because of its insidious onset, osteoporosis renders patients highly susceptible to pathological fractures, leading to increased disability and mortality rates. However, the specific pathogenesis of osteoporosis induced by chronic hyperglycemia has not yet been fully elucidated. But it is currently known that the disruption of Wnt signaling triggered by chronic hyperglycemia is involved in the pathogenesis of diabetic osteoporosis. There are two main types of Wnt signaling pathways, the canonical Wnt signaling pathway (β-catenin-dependent) and the non-canonical Wnt signaling pathway (non-β-catenin-dependent), both of which play an important role in regulating the balance between bone formation and bone resorption. Therefore, this review systematically describes the effects of abnormal Wnt pathway signaling on bone homeostasis under hyperglycemia, hoping to reveal the relationship between Wnt signaling and diabetic osteoporosis to further improve understanding of this disease.

Thymosin beta 4 prevents systemic lipopolysaccharide-induced plaque load in middle-age APP/PS1 mice

Lipopolysaccharide (LPS) produced by the gut during systemic infections and inflammation is thought to contribute to Alzheimer's disease (AD) progression. Since thymosin beta 4 (Tβ4) effectively reduces LPS-induced inflammation in sepsis, we tested its potential to alleviate the impact of LPS in the brain of the APPswePS1dE9 mouse model of AD (APP/PS1) and wildtype (WT) mice. 12.5-month-old male APP/PS1 mice (n = 30) and their WT littermates (n = 29) were tested for baseline food burrowing performance, spatial working memory and exploratory drive in the spontaneous alternation and open-field tests, prior to being challenged with LPS (100ug/kg, i.v.) or its vehicle phosphate buffered saline (PBS). Tβ4 (5 mg/kg, i.v.) or PBS, was administered immediately following and at 2 and 4 h after the PBS or LPS challenge, and then once daily for 6 days (n = 7-8). LPS-induced sickness was assessed though monitoring of changes in body weight and behaviour over a 7-day period. Brains were collected for the determination of amyloid plaque load and reactive gliosis in the hippocampus and cortex. Treatment with Tβ4 alleviated sickness symptoms to a greater extent in APP/PS1 than in WT mice by limiting LPS-induced weight loss and inhibition of food burrowing behaviour. It prevented LPS-induced amyloid burden in APP/PS1 mice but increased astrocytic and microglial proliferation in the hippocampus of LPS-treated WT mice. These data show that Tβ4 can alleviate the adverse effects of systemic LPS in the brain by preventing exacerbation of amyloid deposition in AD mice and by inducing reactive microgliosis in aging WT mice.

Betulinic Acid Exerts Anti-inflammatory Activity in Human Periodontal Ligament Cells Stimulated with Lipopolysaccharide and/or High Glucose

BACKGROUND

Diabetic patients have weakened periodontal ligaments and an increased risk of periodontitis due to uncontrolled glycemia. Betulinic acid (BA), a hypoglycemic drug, has anti-inflammatory activities.

OBJECTIVES

The current study aimed to explore the protective effect of BA on the inflammation in human periodontal ligament cells (PDLCs) stimulated with lipopolysaccharide (LPS) and/or high glucose (HG) status and its mechanisms of action.

METHODS

Human PDLCs were exposed to LPS and/or HG, with or without BA intervention. The production of nitrite oxide (NO) and prostaglandin E2 (PGE2) were quantified by Griess reaction and enzyme-linked immunosorbent assay, respectively. Immunoblotting analyses were employed to detect the expression of inducible nitric oxide synthase (iNOS) and the cyclooxygenase-2 (COX- 2), as well as the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa- B (NF-κB) in human PDLCs.

RESULTS

The increased production of iNOS/NO and COX-2/PGE2 and increased phosphorylated levels of IκBα, JNK, and p38 can be detected in human PDLCs with LPS and/or HG situations, while increased phosphorylated ERK can be seen in cells under only LPS condition. Furthermore, the non-toxic concentration of BA (10 μM) prevented NF-κB and MAPKs activation and partly but significantly reversed the induction of COX-2/ PGE2 and iNOS/NO in human PDLCs with LPS and/or HG loaded.

CONCLUSION

BA was proved for the first time to protect human PDLCs from the LPS-induced and/or HG-induced inflammation, which works through the mechanism involving the action of MAPKs and NF-κB. signaling pathways. Thus, BA could be used to alleviate diabetic complications of periodontitis.

Platelets and osteoblasts: secretome connections

Megakaryocyte hyperplasia associated with myeloproliferative neoplasms commonly leads to abnormal bone tissue deposition in the bone marrow, known as osteosclerosis. In this study, we aimed to synthesize the known proteomics literature describing factors released by megakaryocytes and platelets and to examine if any of the secreted factors have a known ability to stimulate the bone-forming cells, osteoblasts. Using a systematic search of Medline, we identified 77 articles reporting on factors secreted by platelets and megakaryocytes. After a full-text screening and analysis of the studies, we selected seven papers that reported proteomics data for factors secreted by platelets from healthy individuals. From 60 proteins reported in at least two studies, we focused on 23 that contained a putative signal peptide, which we searched for a potential osteoblast-stimulatory function. From nine proteins with a positive effect on osteoblast formation and function, two extracellular matrix (ECM) proteins, secreted protein acidic and rich in cysteine (SPARC) and tissue inhibitor of metalloproteinase-1 (TIMP1), and three cellular proteins with known extracellular function, the 70-kDa heat shock protein (HSP70), thymosin-β4 (TB4), and super dismutase (SOD), were identified as hypothetical candidate molecules to be examined as potential mediators in mouse models of osteomyelofibrosis. Thus, careful analysis of prior literature can be beneficial in assisting the planning of future experimental studies.

TMSB10, a potential prognosis prediction biomarker, promotes the invasion and angiogenesis of gastric cancer

BACKGROUND AND AIM

The thymosin beta 10 (TMSB10) was originally identified from the thymus, which plays a key role in the development of many cancers. However, the underlying molecular mechanisms of TMSB10 involved in GC have not been understood.

METHODS

We sought to determine the expression of TMSB10 in human GC tissues and illustrate whether it is correlated with the clinical pathologic characteristics and prognosis in GC patients. Its roles and potential mechanisms in regulating tumor growth, invasion, and angiogenesis were evaluated by TMSB10 knockdown/overexpression of GC cells in vitro and ex vivo.

RESULTS

Marked overexpression of TMSB10 protein expression was observed in GC cells and tissues, which was associated with the advanced tumor stage and lymph nodes (LN) metastasis of GC patients. Furthermore, prognostic analysis showed that GC patients with high TMSB10 expression had a remarkably shorter survival and acted as an important factor for predicting poor overall survival in GC patients. Moreover, TMSB10 overexpression promoted, while TMSB10 knockdown the proliferation, EMT process, and angiogenesis of GC cells.

CONCLUSION

The study highlights that TMSB10 may hold promise as potential prognosis prediction biomarker for the diagnosis of GC and a potential therapeutic target, which will facilitate the development of a novel therapeutic strategy against GC.

WISP1 alleviates lipid deposition in macrophages via the PPARγ/CD36 pathway in the plaque formation of atherosclerosis

Lipid deposition in macrophages plays an important role in atherosclerosis. The WNT1-inducible signalling pathway protein 1(WISP1) can promote proliferation and migration of smooth muscle cells. Its expression is up-regulated in obesity, which is associated with atherosclerosis, but the effect of WISP1 on atherosclerosis remains unclear. Thus, the objective of our study was to elucidate the role of WISP and its mechanism of action in atherosclerosis via in vivo and in vitro experiments. In our experiment, ApoE-/- mice were divided into 5 groups: control, high-fat diet (HFD), null lentivirus (HFD + NC), lentivirus WISP1 (HFD + IvWISP1) and WISP1-shRNA (HFD + shWISP1). Oil Red O staining, immunofluorescence and immunohistochemistry of the aortic sinuses were conducted. Macrophages (RAW264.7 cell lines and peritoneal macrophages) were stimulated with 50 μg/mL oxidized low-density lipoprotein (ox-LDL); then, the reactive oxygen species (ROS) level was measured. Oil Red O staining and Dil-ox-LDL (ox-LDL with Dil dye) uptake measurements were used to test lipid deposition of peritoneal macrophages. WISP1, CD36, SR-A and PPARγ expression levels were measured via Western blotting and ELISA. The results showed that HFD mice had increased WISP1, CD36 and SR-A levels. The plaque lesion area increased when WISP1 was down-regulated, and lipid uptake and foam cell formation were inhibited when WISP1 was up-regulated. Treatment of RAW264.7 cell lines with ox-LDL increased WISP1 expression via activation of the Wnt5a/β-catenin pathway, whereas ROS inhibition reduced WISP1 expression. Moreover, WISP1 down-regulated CD36 and SR-A expression, and Oil Red O staining and Dil-ox-LDL uptake measurement showed that WISP1 down-regulated lipid deposition in macrophages. These results clearly demonstrate that WISP1 is activated by ox-LDL at high ROS levels and can alleviate lipid deposition in atherosclerosis through the PPARγ/CD36 pathway.

Electrospun thymosin Beta-4 loaded PLGA/PLA nanofiber/ microfiber hybrid yarns for tendon tissue engineering application

Microfiber yarns (MY) have been widely employed to construct tendon tissue grafts. However, suboptimal ultrastructure and inappropriate environments for cell interactions limit their clinical application. Herein, we designed a modified electrospinning device to coat poly(lactic-co-glycolic acid) PLGA nanofibers onto polylactic acid (PLA) MY to generate PLGA/PLA hybrid yarns (HY), which had a well-aligned nanofibrous structure, resembling the ultrastructure of native tendon tissues and showed enhanced failure load compared to PLA MY. PLGA/PLA HY significantly improved the growth, proliferation, and tendon-specific gene expressions of human adipose derived mesenchymal stem cells (HADMSC) compared to PLA MY. Moreover, thymosin beta-4 (Tβ4) loaded PLGA/PLA HY presented a sustained drug release manner for 28 days and showed an additive effect on promoting HADMSC migration, proliferation, and tenogenic differentiation. Collectively, the combination of Tβ4 with the nano-topography of PLGA/PLA HY might be an efficient strategy to promote tenogenesis of adult stem cells for tendon tissue engineering.

Macrophage-Derived Extracellular Vesicles as Carriers of Alarmins and Their Potential Involvement in Bone Homeostasis

Extracellular vesicles are a heterogeneous group of cell-derived membranous structures, which facilitate intercellular communication. Recent studies have highlighted the importance of extracellular vesicles in bone homeostasis, as mediators of crosstalk between different bone-resident cells. Osteoblasts and osteoclasts are capable of releasing various types of extracellular vesicles that promote both osteogenesis, as well as, osteoclastogenesis, maintaining bone homeostasis. However, the contribution of immune cell-derived extracellular vesicles in bone homeostasis remains largely unknown. Recent proteomic studies showed that alarmins are abundantly present in/on macrophage-derived EVs. In this review we will describe these alarmins in the context of bone matrix regulation and discuss the potential contribution macrophage-derived EVs may have in this process.

Improving hard palate wound healing using immune modulatory autotherapies

Oral cavity wound healing occurs in an environment that sustains ongoing physical trauma and is rich in bacteria. Despite this, injuries to the mucosal surface often heal faster than cutaneous wounds and leave less noticeable scars. Patients undergoing cleft palate repair have a high degree of wound healing complications with up to 60% experiencing oronasal fistula (ONF) formation. In this study, we developed a mouse model of hard palate mucosal injury, to study the endogenous injury response during oral cavity wound healing and ONF formation. Immunophenotyping of the inflammatory infiltrate following hard palate injury showed delayed recruitment of non-classical LY6C^lo monocytes and failure to resolve inflammation. To induce a pro-regenerative inflammatory response, delivery of FTY720 nanofiber scaffolds following hard palate mucosal injury promoted complete ONF healing and was associated with increased LY6C^lo monocytes and pro-regenerative M2 macrophages. Alteration in gene expression with FTY720 delivery included increased Sox2 expression, reduction in pro-inflammatory IL-1, IL-4 and IL-6 and increased pro-regenerative IL-10 expression. Increased keratinocyte proliferation during ONF healing was observed at day 5 following FTY720 delivery. Our results show that local delivery of FTY720 from nanofiber scaffolds in the oral cavity enhances healing of ONF, occurring through multiple immunomodulatory mechanisms. STATEMENT OF SIGNIFICANCE: Wound healing complications occur in up to 60% of patients undergoing cleft palate repair where an oronasal fistula (ONF) develops, allowing food and air to escape from the nose. Using a mouse model of palate mucosal injury, we explored the role of immune cell infiltration during ONF formation. Delivery of FTY720, an immunomodulatory drug, using a nanofiber scaffold into the ONF was able to attract anti-inflammatory immune cells following injury that enhanced the reepithelization process. ONF healing at day 5 following FTY720 delivery was associated with altered inflammatory and epithelial transcriptional gene expression, increased anti-inflammatory immune cell infiltration, and increased proliferation. These findings demonstrate the potential efficacy of immunoregenerative therapies to improve oral cavity wound healing.

Secreted frizzled-related protein 5 serum levels in human periodontitis-A nested case-control study

AIM

Recombinant secreted frizzled-related protein 5 (sFRP5) improved periodontal status in mice. Thus, this study aimed to investigate this finding in human periodontitis using an epidemiological approach.

MATERIALS AND METHODS

sFRP5 and wnt5a concentrations were determined in human serum from the Food Chain Plus cohort using ELISAs. A total of 128 patients with periodontitis and tooth loss and 245 patients with periodontitis without tooth loss were compared to 373 sex-, smoker-, age- and BMI-matched individuals in a nested case-control design.

RESULTS

Systemic sFRP5 serum levels were significantly lower in patients with periodontitis and tooth loss (2.5 [0.0-10.4] ng/ml, median [IQR]) compared to patients with periodontitis without tooth loss (6.0 [2.5-15.8] ng/ml, median [IQR], p = 0.04] and matched controls (7.0 [2.5-18.3] ng/ml, median [IQR], p = 0.02). No significant differences in sFRP5 serum levels were found among patients with periodontitis without tooth loss (6.0 [2.5-15.8] ng/ml, median [IQR]) and controls (3.1 [0.0-10.6] ng/ml, median [IQR], p = 0.06).

CONCLUSIONS

sFRP5 might serve as a novel biomarker for periodontitis severity. Modulating the inflammatory background of severe forms of periodontitis, in the time of precision medicine, needs to be revealed in further studies.

Anti-Inflammatory Activity of β-thymosin Peptide Derived from Pacific Oyster (Crassostrea gigas) on NO and PGE₂ Production by Down-Regulating NF-κB in LPS-Induced RAW264.7 Macrophage Cells

β-thymosin is known for having 43 amino acids, being water-soluble, having a light molecular weight and ubiquitous polypeptide. The biological activities of β-thymosin are diverse and include the promotion of wound healing, reduction of inflammation, differentiation of T cells and inhibition of apoptosis. Our previous studies showed that oyster β-thymosin originated from the mantle of the Pacific oyster, Crassostrea gigas and had antimicrobial activity. In this study, we investigated the anti-inflammatory effects of oyster β-thymosin in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells using human β-thymosin as a control. Oyster β-thymosin inhibited the nitric oxide (NO) production as much as human β-thymosin in LPS-induced RAW264.7 cells. It also showed that oyster β-thymosin suppressed the expression of prostaglandin E₂ (PGE₂), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, oyster β-thymosin reduced inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Oyster β-thymosin also suppressed the nuclear translocation of phosphorylated nuclear factor-κB (NF-κB) and degradation of inhibitory κB (IκB) in LPS-induced RAW264.7 cells. These results suggest that oyster β-thymosin, which is derived from the mantle of the Pacific oyster, has as much anti-inflammatory effects as human β-thymosin. Additionally, oyster β-thymosin suppressed NO production, PGE₂ production and inflammatory cytokines expression via NF-κB in LPS-induced RAW264.7 cells.

Thymosin β4 prevents oxygen-glucose deprivation/reperfusion-induced injury in rat cortical neurons

PURPOSE

This study investigated whether thymosin (T) β4 protects against oxygen-glucose deprivation/reperfusion (OGD/R) injury in rat cortical neurons, as well as the underlying mechanisms.

METHODS

Primary rat cortical neurons were transfected with Tβ4 overexpression plasmid; the transfection efficiency was confirmed by detecting Tβ4 expression by fluorescence quantitative PCR and Western blotting. The OGD/R model was established and apoptotic cells were quantified by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling. Structural changes in the endoplasmic reticulum were visualized by transmission electron microscopy. The expression levels of 78-kDa glucose-regulated protein (GRP) 78, C/EBP-homologous protein (CHOP), B-cell lymphoma (Bcl)-2, and Bcl-2-associated X protein (Bax) were determined by Western blotting. The effect of Tβ4 on OGD/R injury was evaluated by adding exogenous Tβ4 to neuronal cultures.

RESULTS

Cortical neurons were identified by the expression of neuron-specific enolase. In OGD/R cells, the rate of apoptosis was increased and GRP78, CHOP, and Bax were upregulated whereas Bcl-2 was downregulated relative to the control group. These effects were reversed by Tβ4 overexpression. Endoplasmic reticulum (ER) stress was observed in the OGD/R group, but this was abolished in neurons overexpressing Tβ4. The protective effect of Tβ4 against OGD/R injury was also demonstrated in cells treated with exogenous Tβ4 (10 ng/mL), which blocked OGD/R-induced apoptosis by inhibiting ER stress-related and pro-apoptotic protein expression.

CONCLUSION

Tβ4 prevents OGD/R-induced ER stress-dependent apoptosis in cortical neurons, and is a potential treatment for cerebral ischemia-reperfusion injury.

Moonlighting Activity of Secreted Inflammation-Regulatory Proteins

Moonlighting proteins exhibit multiple activities in different cellular compartments, and their abnormal regulation could play an important role in many diseases. To date, many proteins have been identified with moonlighting activity, and more such proteins are being gradually identified. Among the proteins that possess moonlighting activity, several secreted proteins exhibit multiple activities in different cellular locations, such as the extracellular matrix, nucleus, and cytoplasm. While acute inflammation starts rapidly and generally disappears in a few days, chronic inflammation can last for months or years. This is generally because of the failure to eliminate the cause of inflammation, along with repeated exposure to the inflammatory agent. Chronic inflammation is now considered as an overwhelming burden to the general wellbeing of patients and noted as an underlying cause of several diseases. Moonlighting proteins can contribute to the process of chronic inflammation; therefore, it is imperative to overview some proteins that exhibit multiple functions in inflammatory diseases. In this review, we will focus on inflammation, particularly unravelling several well-known secreted proteins with multiple functions in different cellular locations.

Salidroside promotes human periodontal ligament cell proliferation and osteocalcin secretion via ERK1/2 and PI3K/Akt signaling pathways

Salidroside modulates cell proliferation and serves as an anti-inflammatory and anti-apoptotic agent with efficacy against various diseases. The objective of the present study was to investigate the efficacy of salidroside in enhancing the proliferation of human periodontal ligament cells (hPDLCs). hPDLCs were isolated and the effects of salidroside on cell viability, soluble osteocalcin levels and activation of proliferation-associated signaling pathways were determined using a CCK-8 assay, ELISA and Western blotting, respectively. The results indicated that salidroside induced proliferation of hPDLCs, increased secretion of soluble osteocalcin and enhanced activation of extracellular signal-regulated kinase (ERK)1/2 and phosphoinositide-3 kinase (PI3K)/Akt signaling pathways. These factors were upregulated by salidroside in a dose-dependent manner. The results of the present study suggested that salidroside mediated hPDLC proliferation via the ERK1/2 and PI3K/Akt signaling pathways, as well as osteocalcin secretion. Salidroside may therefore be used as a novel therapeutic agent in the treatment of the tooth-supporting apparatus, progressive tooth destruction or periodontitis.

Thymosin β4 in rheumatoid arthritis: Friend or foe

Rheumatoid arthritis (RA) has characteristic pannus tissues, which show tumor-like growth of the synovium through chronic joint inflammation. The synovium is highly penetrated by various immune cells, and the synovial lining becomes hyperplastic due to increased numbers of macrophage-like and fibroblast-like synoviocytes. Thus, a resultant hypoxic condition stimulates the expression of inflammation-related genes in various cells, in particular, vascular endothelial growth factor. Thymosin β4 (Tβ4), a 5-kDa protein, is known to play a significant role in various biological activities, such as actin sequestering, cell motility, migration, inflammation, and damage repair. Recent studies have provided evidence that Tβ4 may have a role in RA pathogenesis. The Tβ4 level has been shown to increase significantly in the joint fluid and serum of RA patients. However, whether Tβ4 stimulates or inhibits activation of RA immune responses remains to be determined. In the present study, we discuss the logical and clinical justifications for Tβ4 as a potential target for RA therapeutics.

Nrf2 Inhibits Periodontal Ligament Stem Cell Apoptosis under Excessive Oxidative Stress

The present study aimed to analyze novel mechanisms underlying Nrf2-mediated anti-apoptosis in periodontal ligament stem cells (PDLSCs) in the periodontitis oxidative microenvironment. We created an oxidative stress model with H₂O₂-treated PDLSCs. We used real-time PCR, Western blotting, TUNEL staining, fluorogenic assay and transfer genetics to confirm the degree of oxidative stress and apoptosis as well as the function of nuclear factor-erythroid 2-related factor 2 (Nrf2). We demonstrated that with upregulated levels of reactive oxygen species (ROS) and malondialdehyde (MDA), the effect of oxidative stress was obvious under H₂O₂ treatment. Oxidative molecules were altered after the H₂O₂ exposure, whereby the signaling of Nrf2 was activated with an increase in its downstream effectors, heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1) and γ-glutamyl cysteine synthetase (γ-GCS). Additionally, the apoptosis levels gradually increased with oxidative stress by the upregulation of caspase-9, caspase-3, Bax and c-Fos levels in addition to the downregulation of Bcl-2. However, there was no alterations in levels of caspase-8. The enhanced antioxidant effect could not mitigate the occurrence of apoptosis. Furthermore, Nrf2 overexpression effectively improved the anti-oxidative levels and increased cell proliferation. At the same time, overexpression effectively restrained TUNEL staining and decreased the molecular levels of caspase-9, caspase-3, Bax and c-Fos, but not that of caspase-8. In contrast, silencing the expression of Nrf2 levels had the opposite effect. Collectively, Nrf2 alleviates PDLSCs via its effects on regulating oxidative stress and anti-intrinsic apoptosis by the activation of oxidative enzymes.

Thymosin beta 10 is a key regulator of tumorigenesis and metastasis and a novel serum marker in breast cancer

Background

Thymosin beta 10 (TMSB10) has been demonstrated to be involved in the malignant process of many cancers. The purpose of this study was to determine the biological roles and clinical significance of TMSB10 in breast cancer and to identify whether TMSB10 might be used as a serum marker for the diagnosis of breast cancer.

Methods

TMSB10 expression was evaluated by immunohistochemical analysis (IHC) of 253 breast tumors and ELISA of serum from 80 patients with breast cancer. Statistical analysis was performed to explore the correlation between TMSB10 expression and clinicopathological features in breast cancer. Univariate and multivariate Cox regression analysis were performed to examine the association between TMSB10 expression and overall survival and metastatic status. In vitro and in vivo assays were performed to assess the biological roles of TMSB10 in breast cancer. Western blotting and luciferase assays were examined to identify the underlying pathway involved in the tumor-promoting role of TMSB10.

Results

We found TMSB10 was upregulated in breast cancer cells and tissues. Univariate and multivariate analysis demonstrated that high TMSB10 expression significantly correlated with clinicopathological features, poor prognosis and distant metastases in patients with breast cancer. Overexpression of TMSB10 promotes, while silencing of TMSB10 inhibits, proliferation, invasion and migration of breast cancer cells in vitro and in vivo. Our results further reveal that TMSB10 promotes the proliferation, invasion and migration of breast cancer cells via AKT/FOXO signaling, which is antagonized by the AKT kinase inhibitor perifosine. Importantly, the expression of TMSB10 is significantly elevated in the serum of patients with breast cancer and is positively associated with clinical stages of breast cancer.

Conclusion

TMSB10 may hold promise as a minimally invasive serum cancer biomarker for the diagnosis of breast cancer and a potential therapeutic target which will facilitate the development of a novel therapeutic strategy against breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0785-2) contains supplementary material, which is available to authorized users.

Co-Cr dental alloys induces cytotoxicity and inflammatory responses via activation of Nrf2/antioxidant signaling pathways in human gingival fibroblasts and osteoblasts

OBJECTIVE

Although cobalt-chromium (Co-Cr) dental alloys are routinely used in prosthodontics, the biocompatibility of Co-Cr alloys is controversial. The aims of the present study were to investigate the effects of Co-Cr alloys on human gingival fibroblasts (HGF) and osteoblasts in an in vitro model as well as their potential molecular mechanisms, focusing on NF-E2-related factor 2 (Nrf2) pathways.

METHODS

Cells were directly seeded on prepared Co-Cr alloy discs (15.0mm diameter, 1.0mm thickness) or indirectly treated with Co-Cr alloy located at the bottom of an insert well and incubated for 3 days. Cytotoxicity and reactive oxygen species (ROS) production was evaluated by MTS assay and flow cytometry, respectively. Protein and mRNA levels were determined by Western blotting and RT-PCR analysis, respectively.

RESULTS

Cell viability and flow cytometric assay demonstrated that the Co-Cr alloy was cytotoxic to HGFs and osteoblasts, and significantly increased ROS production. In addition, the Co-Cr alloys upregulated pro-inflamamtory cytokines (TNF-α, IL-1β, IL-6, and IL-8) and increased levels of various inflammatory mediators (iNOS derived nitrite oxide, and COX-2-derived PGE2) in both cells. A mechanistic study showed that Co-Cr alloys activates the NRF2 pathway and up-regulate antioxidant enzymes including heme oxygenase-1 (HO-1). Co-Cr alloys activated JAK2/STAT3, p38/ERK/JNK MAPKs and NF-κB signaling pathways. Furthermore, antioxidants (resveratrol and NAC) and HO-1 inhibitor (SnPP) significantly inhibited the production of ROS and inflammatory mediators, as well as the activation of NF-κB signaling in Co-Cr alloy stimulated HGFs and osteoblasts.

SIGNIFICANCE

This study is the first to show that Co-Cr alloys exert cytotoxic and inflammatory effects via activation of Nrf2/ARE signaling and up-regulation of downstream HO-1, which could represent candidate targets for the regulation of inflammatory responses to Co-Cr alloys.

Follicle-stimulating hormone enhances alveolar bone resorption via upregulation of cyclooxygenase-2

This study aimed to investigate whether follicle-stimulating hormone (FSH)-induced alveolar bone resorption was mediated by a cyclooxygenase 2 (COX-2) enzyme related mechanism. Experimental periodontitis was induced in bilateral ovariectomized (OVX) rats, some of which were injected with triptorelin, an FSH inhibitor. After mandibles were collected, we performed micro-computed tomography to evaluate alveolar bone loss and immunohistochemical staining to assess COX-2 expression. As well, human periodontal ligament cells (PDLCs) were treated with FSH (30 ng/ml), and the COX-2 mRNA and protein expression levels were measured by quantitative real-time polymerase chain reaction (qPCR) and Western blotting, respectively; prostaglandin E2 (PGE₂) levels were measured by enzyme-linked immunosorbent assay (ELISA). The results indicated that FSH significantly increased alveolar bone resorption and the expression of COX-2 in the bilateral OVX + Ligatured rats compared with the other treatment groups. FSH also increased the mRNA and protein expression of COX-2 and PGE₂ (P < 0.01) in human PDLCs. Further, the analysis of signaling pathways revealed the activation of COX-2-mediated pathways including Erk, p38, and Akt. These data suggest that FSH aggravates alveolar bone loss via a COX-2-upregulation mechanism and that the Erk, p38, and Akt pathways are involved in this pathological process.