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Telomeres play a central role in cellular aging, and shorter telomere length has been associated with age-related disorders including diabetes. However, a causal link between telomere shortening and diabetes risk has not been established. In a wellcharacte

Short telomere length, a marker of biological aging, has been associated with age-related metabolic disorders. Telomere attrition induces profound metabolic dysfunction in animal models, but no study has examined the metabolome of telomeric aging in human.

Short leukocyte telomere length (LTL) has been associated with atherosclerosis in cross-sectional studies, but the prospective relationship between telomere shortening and risk of developing carotid atherosclerosis has not been wellestablished. This study

Shorter leukocyte telomere length (LTL) has been associated with a wide range of age-related disorders including cardiovascular disease (CVD) and diabetes. Obesity is an important risk factor for CVD and diabetes. The association of LTL with obesity is not

Telomeres play a central role in cellular senescence and are associated with a variety of age-related disorders such as dementia, Alzheimer's disease and atherosclerosis. Telomere length varies greatly among individuals of the same age, and is heritable. H

During orthodontic tooth movement, mechanical stresses induce inflammatory reactions in the periodontal ligament (PDL). We hypothesized that chemokines released from PDL cells under mechanical stress regulate osteoclastogenesis, and investigated the profiles and mechanisms of chemokine expression by human PDL cells in response to mechanical stress. In vitro, shear stress and pressure force rapidly increased the gene and protein expressions of IL-8/CXCL8 by PDL cells. Consistently, amounts of IL-8 in the gingival crevicular fluid of healthy individuals increased within 2 to 4 days of orthodontic force application. The PDL cells constitutively expressed low levels of IL-1beta, which were not further increased by mechanical stress. Interestingly, neutralization of IL-1beta abolished IL-8 induction by mechanical stresses, indicating that IL-1beta is essential for IL-8 induction, presumably though autocrine or paracrine mechanisms. Finally, experiments with signal-specific inhibitors indicated that MAP kinase activation is essential for IL-8 induction. [ABSTRACT FROM AUTHOR]

A 12 lead electrocardiogram was recorded during treadmill exercise in 57 patients with variant angina in whom coronary angiography was performed. Thirty six patients performed exercise tests with and without calcium antagonists, and 21 performed them only with calcium antagonists. In 55 patients calcium antagonists had prevented spontaneous attacks of variant angina for more than two days before the test. The other two patients were given a single dose of diltiazem (90 mg) two hours before the test. Exercise testing without calcium antagonists induced ST segment elevation with chest pain in nine patients, ST segment depression in 10 (nine with chest pain), and no important shift of the ST segment in 17. Five patients had severe coronary stenosis (greater than or equal to 75%) and all of them showed positive response. Thirty one patients had no important coronary stenosis and 14 of them showed positive response. The sensitivity of the exercise test in detecting a coronary stenosis greater than or equal to 75% was 100% without calcium antagonists but the specificity was low (55%). When the exercise test was done in patients taking calcium antagonists, only two (specificity 96%) of 48 patients without severe coronary stenosis showed positive response (elevation of ST segment in one and depression in another) whereas all nine patients with severe coronary stenosis had a positive response (depression of ST segment in six and elevation in three (sensitivity 100%). It is concluded that exercise testing with calcium antagonists may be a useful method for detecting severe coronary stenosis in patients with variant angina. [ABSTRACT FROM PUBLISHER]

The effect of alcohol on variant angina was studied in six patients who had a history of chest pain occurring with alcohol ingestion. On alcohol testing, Holter ECG monitoring was performed and a 12-lead ECG was recorded at the time of chest pain. In five, chest pain with ST elevation occurred 5.5 to 17.5 h after the ingestion of alcohol (100 to 150 ml as ethanol). These showed recurrent ST elevation on Holter ECG, most episodes being asymptomatic. Results of provocation testing were reproducible in all four patients in whom tests were repeated and ST elevation occurred in the same leads. No complications were observed. The Holter ECG revealed a higher heart rate after alcohol ingestion. The plasma level of alcohol was zero when angina occurred and plasma epinephrine, norepinephrine and serotonin were unchanged following alcohol ingestion. Alcohol ingestion may be a useful method of provoking variant angina, particularly in those who have a history of angina related to alcohol ingestion. [ABSTRACT FROM PUBLISHER]

Osteopontin (OPN) is expressed in various cell types including osteoblasts. OPN expression level is robustly increased during osteoblast differentiation. Although OPN was initially found as a secretory protein (sOPN), recent reports identified the intracellular isoform of OPN (iOPN). Distinct functions of each OPN isoform in osteoblasts, however, are not well established. Here, using the Tet-On inducible expression system, we examined the role of each OPN isoform during osteoblast differentiation. Induced overexpression of wild type OPN (wtOPN), which includes both sOPN and iOPN, significantly increased matrix mineralization and osteogenic marker gene expression during osteogenic differentiation induced by either ascorbic acid or bone morphogenetic protein (BMP) 9. In contrast, these osteogenic differentiation processes were significantly inhibited by the specific overexpression of iOPN. Furthermore, the addition of recombinant OPN or neutralizing anti-OPN antibody to the culture medium exerted promotive or inhibitory effect on osteoblast differentiation, respectively. These data strongly indicate that iOPN exerts inhibitory effects on osteoblast differentiation, whereas sOPN exerts positive effects. We also found that the secretion process of OPN is positively regulated by c-Jun N-terminal kinase (JNK) activity in osteoblasts., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.)

Gingival epithelial cells (GECs) are physical and immunological barriers against outward pathogens while coping with a plethora of non-pathogenic commensal bacteria. GECs express several members of Toll-like receptors (TLRs) and control subsequent innate immune responses. TLR4 senses lipopolysaccharide (LPS) while TLR7/8 recognizes single-strand RNA (ssRNA) playing important roles against viral infection. However, their distinct roles in GECs have not been fully demonstrated. Here, we analyzed biological responses of GECs to  LPS and CL075, a TLR7/8 agonist. GE1, a mouse gingival epithelial cell line, constitutively express TLR4 and TLR7, but not TLR8, like primary skin keratinocytes. Stimulation of GE1 cells with CL075 induced cytokine, chemokine, and antimicrobial peptide  expressions, the pattern of which is rather different from that with LPS: higher mRNA levels of interferon (IFN) β, CXCL10, and β-defensin (BD) 14 (mouse homolog of human BD3); lower levels of tumor necrosis factor (TNF), CCL5, CCL11, CCL20, CXCL2, and CX3CL1. As for the intracellular signal transduction of GE1 cells, CL075 rapidly induced significant AKT phosphorylation but failed to activate IKKα/β-NFκB pathway, whereas LPS induced marked IKKα/β-NFκB activation without significant AKT phosphorylation. In contrast, both CL075 and LPS induced rapid IKKα/β-NFκB activation and AKT phosphorylation in a macrophage cell line. Furthermore, specific inhibition of AKT activity abrogated CL075-induced IFNβ, CXCL10, and BD14 mRNA expression in GE1 cells. Thus, TLR4/7 ligands appear to induce rather different host-defense responses of GECs through distinct intracellular signaling mechanisms., (© 2024 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals LLC.)

Bone morphogenic protein 9 (BMP9) is one of the most potent inducers of osteogenic differentiation among the 14 BMP members, but its mechanism of action has not been fully demonstrated. Hes1 is a transcriptional regulator with basic helix-loop-helix (bHLH) domain and is a well-known Notch effector. In this study, we investigated the functional roles of early induction of Hes1 by BMP9 in a mouse mesenchymal stem cell line, ST2. Hes1 mRNA was transiently and periodically induced by BMP9 in ST2, which was inhibited by BMP signal inhibitors but not by Notch inhibitor. Interestingly, Hes1 knockdown in ST2 by siRNA increased the expression of osteogenic differentiation markers such as Sp7 and Ibsp and matrix mineralization in comparison with control siRNA transfected ST2. In contrast, forced expression of Hes1 by using the Tet-On system suppressed the expression of osteogenic markers and matrix mineralization by BMP9. We also found that the early induction of Hes1 by BMP9 suppressed the expression of Alk1, an essential receptor for BMP9. In conclusion, BMP9 rapidly induces the expression of Hes1 via the SMAD pathway in ST2 cells, which plays a negative regulatory role in osteogenic differentiation of mesenchymal stem cells induced by BMP9., (© 2023 Wiley Periodicals LLC.)

Lipoteichoic acid (LTA) and lipopolysaccharide (LPS) are cell wall components of Gram-positive and Gram-negative bacteria, respectively. Notably, oral microflora consists of a variety of bacterial species, and osteomyelitis of the jaw caused by dental infection presents with symptoms of bone resorption and osteosclerosis. However, the effects of LTA and LPS on osteogenic differentiation have not yet been clarified. We examined the effects of LTA and LPS on osteoblasts and found that LTA alone promoted alizarin red staining at low concentrations and inhibited it at high concentrations. Additionally, gene expression of osteogenic markers (ALP, OCN, and OPG) were enhanced at low concentrations of LTA. High concentrations of LPS suppressed calcification potential, and the addition of low concentrations of LTA inhibited calcification suppression, restoring the gene expression levels of suppressed bone differentiation markers (ALP, BSP, and OCN). Moreover, the suppression of p38, a signaling pathway associated with bone differentiation, had opposing effects on gene-level expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), suggesting that mixed LTA and LPS infections have opposite effects on bone differentiation through concentration gradients, involving inflammatory markers (TNF-α and IL-6) and the p38 pathway.

Bone morphogenetic proteins (BMPs) are essential regulators of skeletal homeostasis, and BMP9 is the most potently osteogenic among them. Here, we found that BMP9 and BMP2 rapidly induced early growth response 1 (EGR1) protein expression in osteoblasts through MEK/ERK pathway-dependent transcriptional activation. Knock-down of EGR1 using siRNA significantly inhibited BMP9-induced matrix mineralization and osteogenic marker gene expression in osteoblasts. Knock-down of EGR1 significantly reduced SMAD1/5 phosphorylation and inhibited the expression of their transcriptional targets in osteoblasts stimulated by BMP9. In contrast, forced EGR1 overexpression in osteoblasts enhanced BMP9-mediated osteoblast differentiation and SMAD1/5 phosphorylation. An intracellular association between EGR1 and SMAD1/5 was identified using immunoprecipitation assays. These results indicated that EGR1 plays an important role in BMP9-stimulated osteoblast differentiation by enhancing SMAD1/5 phosphorylation., (© 2022 Federation of European Biochemical Societies.)

Objectives: The oral cavity is one of the main entry sites for SARS-CoV-2. Gingival keratinocytes express transmembrane serine protease 2 (TMPRSS2), responsible for priming the SARS-CoV-2 spike protein. We investigated whether periodontitis increased the expression of TMPRSS2., Methods: To investigate gene expression in periodontitis, we analyzed the expression of specific genes from (1) the Gene Expression Omnibus (GEO) dataset of 247 human gingival tissues and (2) an experimentally-induced periodontitis mouse model. Human gingival tissues with or without periodontitis were immunohistochemically stained using an anti-TMPRSS2 antibody. Analysis of the TMPRSS2 promoter was performed using a ChIP-Atlas dataset. TMPRSS2 expression was detected in cultured human keratinocytes using quantitative reverse transcription (qRT)-PCR and Western blot analysis., Results: GEO dataset analysis and an experimentally-induced periodontitis model revealed increased expression of TMPRSS2 in periodontitis gingiva. The keratinocyte cell membrane in periodontitis gingiva was strongly immunohistochemically stained for TMPRSS2. Using ChIP-Atlas and GEO datasets, we screened for transcription factors that bind to the TMPRSS2 promoter region. We found one candidate, estrogen receptor 1 (ESR1), highly expressed in periodontitis gingiva. Analysis of the GEO dataset revealed a correlation between ESR1 and TMPRSS2 expression in gingival tissues. An ESR1 ligand induced TMPRSS2 expression in cultured keratinocytes., Conclusions: Periodontitis increases TMPRSS2 expression in the cell membrane of gingival keratinocytes., (Copyright © 2022 Japanese Association for Oral Biology. Published by Elsevier B.V. All rights reserved.)

Bone homeostasis is regulated by bone morphogenic proteins (BMPs), among which BMP9 is one of the most osteogenic. Here, we have found that BMP9 rapidly increases the protein expression of hypoxia-inducible factor-1α (HIF-1α) in osteoblasts under normoxic conditions more efficiently than BMP2 or BMP4. A combination of BMP9 and hypoxia further increased HIF-1α protein expression. HIF-1α protein induction by BMP9 is not accompanied by messenger RNA (mRNA) increase and is inhibited by the activation of prolyl hydroxylase domain (PHD)-containing protein, indicating that BMP9 induces HIF-1α protein expression by inhibiting PHD-mediated protein degradation. BMP9-induced HIF-1α protein increase was abrogated by inhibitors of phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) kinase, indicating that it is mediated by PI3K-AKT signaling pathway. BMP9 increased mRNA expression of pyruvate dehydrogenase kinase 1 (PDK1), a glycolytic enzyme, and vascular endothelial growth factor-A (VEGF-A), an angiogenic factor, in osteoblasts. Notably, BMP9-induced mRNA expression of PDK1, but not that of VEGF-A, was significantly inhibited by small interference RNA-mediated knockdown of Hif-1α. BMP9-induced matrix mineralization and osteogenic marker gene expressions were significantly inhibited by chemical inhibition and gene knockdown of either Hif-1α or Pdk-1, respectively. Since increased glycolysis is an essential feature of differentiated osteoblasts, our findings indicate that HIF-1α expression is important in BMP9-mediated osteoblast differentiation through the induction of PDK1., (© 2022 Wiley Periodicals LLC.)

Objectives: The colonic self-expandable metallic stent (C-SEMS) with a 9-French (Fr) delivery system allows for a small-caliber endoscope (SCE) to be used to treat malignant colonic obstruction. Despite the lack of evidence, the SCE has become popular because it is considered easier to insert than the large-caliber endoscope (LCE). We aimed to determine whether the SCE is more suitable than the LCE for C-SEMS placement., Methods: Between July 2018 and November 2019, 50 consecutive patients who were scheduled to undergo C-SEMS for colon obstruction were recruited in this study. Patients were randomized to the SCE or LCE group. The SCE and LCE were used with 9-Fr and 10-Fr delivery systems, respectively. The primary outcome was the total procedure time. Secondary outcomes were the technical success rate, complication rate, clinical success rate, insertion time, guidewire-passage time, stent-deployment time, and colonic obstruction-scoring-system score., Results: Forty-five patients (SCE group, n = 22; LCE group, n = 23) were analyzed. The procedure time in the LCE group (median, 20.5 min) was significantly ( p = 0.024) shorter than that in the SCE group (median, 25.1 min). The insertion time in the LCE group (median, 2.0 min) was significantly ( p = 0.0049) shorter than that in the SCE group (median, 6.0 min). A sub-analysis of the procedure difficulties showed that the insertion time in the LCE group (median, 5.0 min) was significantly shorter than that in the SCE group (median, 8.5 min)., Conclusion: Both LCE and SCE can be used for C-SEMS; however, LCE is more suitable than SCE as it achieved a faster and equally efficacious C-SEMS placement as that of SCE., Clinical Trial Registration Number: University Hospital Medical Information Network Clinical Trials Registry (UMIN 32748)., Competing Interests: Conflict of interest statement: The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: EI belongs to an endowed course supported by the companies Ono Pharmaceutical Co., Ltd, Miyarisan Pharmaceutical Co. Ltd, Sanwa Kagaku Kenkyusho Co., Ltd, Otsuka Pharmaceutical Factory, Inc., Fujifilm Medical Co., Ltd, Terumo Corporation, FANCL Corporation, Ohga Pharmacy, and Abbott Japan, LLC. EI receives lecture honorarium from Takeda Pharmaceutical Company. YO conducts collaborative research with Fujifilm Medical Co., Ltd and FANCL Corporation. The authors declare no other conflicts of interest in association with this study., (© The Author(s), 2022.)

Objectives: Traditionally, evaluation is considered a measurement process that can be performed independently of the cultural context. However, more recently the importance of considering raters' sense-making, that is, the process by which raters assign meaning to their collective experiences, is being recognised. Thus far, the majority of the discussion on this topic has originated from Western perspectives. Little is known about the potential influence of an Asian culture on raters' sense-making. This study explored residents' sense-making associated with evaluating their clinical teachers within an Asian setting to better understand contextual dependency of validity., Design: A qualitative study using constructivist grounded theory., Setting: The Japanese Ministry of Health, Labour and Welfare has implemented a system to monitor the quality of clinical teaching within its 2-year postgraduate training programme. An evaluation instrument was developed specifically for the Japanese setting through which residents can evaluate their clinical teachers., Participants: 30 residents from 10 Japanese teaching hospitals with experience in evaluating their clinical teachers were sampled purposively and theoretically., Methods: We conducted in-depth semistructured individual interviews. Sensitising concepts derived from Confucianism and principles of response process informed open, axial and selective coding., Results: Two themes and four subthemes were constructed. Japanese residents emphasised the awareness of their relationship with their clinical teachers (1). This awareness was fuelled by their sense of hierarchy (1a) and being part of the collective society (1b). Residents described how the meaning of evaluation (2) was coloured by their perceived role as senior (2a) and their experienced responsibility for future generations (2b)., Conclusions: Japanese residents' sense-making while evaluating their clinical teachers appears to be situated and affected by Japanese cultural values. These findings contribute to a better understanding of a culture's influence on residents' sense-making of evaluation instruments and the validity argument of evaluation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Ultraviolet radiation is one of the standard treatment selections for psoriasis. interferon (IFN)-γ and IFN-γ-induced CXCL10, which are highly expressed by keratinocytes in psoriasis lesion, are therapeutic targets for psoriasis. In this study, we found that ultraviolet B (UVB) irradiation inhibited IFN-γ signaling events, including STAT1 phosphorylation and induction of CXCL10 messenger RNA (mRNA) expression in keratinocytes. IFN-γ-induced expression of CXCL10 mRNA in HaCaT cells, a human keratinocyte cell line, and human epithelial keratinocytes were also inhibited by H 2 O 2 or endoplasmic reticulum (ER) stress inducers. Conversely, a mixture of antioxidants, Trolox and ascorbic acid, and the ER stress inhibitor salubrinal partially counteracted the inhibitory effect of UVB on IFN-γ-induced CXCL10 mRNA expression in HaCaT cells. We also found that UVB and ER stress reduced IFN-γ receptor 1 protein levels in the plasma membrane fraction of keratinocytes. These observations suggested that ER stress and the generation of reactive oxygen species are essential for the inhibitory effect of UVB on IFN-γ-induced CXCL10 mRNA in keratinocytes., (© 2021 Wiley Periodicals LLC.)

Bone morphogenetic protein (BMP) 9 is one of the most osteogenic BMPs, but its mechanism of action has not been fully elucidated. Hes1, a transcriptional regulator with a basic helix-loop-helix domain, is a well-known effector of Notch signaling. Here, we find that BMP9 induces periodic increases of Hes1 mRNA and protein expression in osteoblasts, presumably through an autocrine negative feedback mechanism. BMP9-mediated Hes1 induction is significantly inhibited by an ALK inhibitor and overexpression of Smad7, an inhibitory Smad. Luciferase and ChIP assays revealed that two Smad-binding sites in the 5' upstream region of the mouse Hes1 gene are essential for transcriptional activation by BMP9. Thus, our data indicate that BMP9 induces Hes1 expression in osteoblasts via the Smad signaling pathway., (© 2020 Federation of European Biochemical Societies.)

Background: Endoscopic submucosal dissection (ESD) is a standard treatment for tumors of the gastrointestinal tract. We developed a self-completion method of ESD using Endosaber to eliminate the need for an additional device or human assistance during the procedure. The aim of this study was to evaluate the technical feasibility and outcomes of this method in an ex vivo porcine training model., Methods: This was a pilot study, and the procedures were performed by 4 experts. Mock lesions measuring 15 mm in diameter were prepared at the posterior wall in the middle or lower esophagus obtained from domestic pigs. Each operator performed ESD on the mock lesions in 3 models. The primary outcome was ESD completion rate using the self-completion method. The secondary outcomes were procedure time, en bloc resection rate, perforation rate, and number of injections during the procedure., Results: All 12 ESDs were completed using the self-completion method. The median procedure time (interquartile range) was 483.5 (399-619.3) s (median incision time: 240.4 [168.3-332.5] s; median dissection time: 222 [182.8-257] s). En bloc resection rate was 100%. No perforation was noted during any of the procedures. The median number of injections was 10.5 (9-14.3). The procedure time decreased significantly with increase in experience (p = 0.020)., Conclusions: The self-completion ESD method using one Endosaber without any assistance achieved a 100% en bloc resection rate without any perforation. The need for an additional device or assistance was successfully eliminated. This method may prove to be a simple and cost-effective ESD procedure for lesions in humans., (© 2019 S. Karger AG, Basel.)

The glycolytic system is selected for ATP synthesis not only in tumor cells but also in differentiated cells. Differentiated osteoblasts also switch the dominant metabolic pathway to aerobic glycolysis. We found that primary osteoblasts increased expressions of glycolysis-related enzymes such as Glut1, hexokinase 1 and 2, lactate dehydrogenase A and pyruvate kinase M2 during their differentiation. Osteoblast differentiation decreased expression of tumor suppressor p53, which negatively regulates Glut1 expression, and enhanced phosphorylation of AKT, which is regulated by phosphoinositol-3 kinase (PI3K). An inhibitor of PI3K enhanced p53 expression and repressed Glut1 expression. Luciferase reporter assay showed that p53 negatively regulated transcriptional activity of solute carrier family 2 member 1 gene promoter region. Inhibition of glycolysis in osteoblasts reduced ATP contents more significantly than inhibition of oxidative phosphorylation by carbonyl cyanide m-chlorophenyl hydrazine. These results have indicated that osteoblasts increase Glut1 expression through the down-regulation of p53 to switch their metabolic pathway to glycolysis during differentiation., (© 2020 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Background/aims: It is important to appropriately manage patients with procedure-related artificial mucosal ulcers or procedure-related complications. Many endoscopic closure techniques have been reported; however, they often require the use of special devices. We developed a single-channel endoscopic closure technique (SCCT) that can be performed with conventional devices. In the present study, we describe the technique and evaluate its efficacy., Methods: Twenty-five consecutive patients who underwent endoscopic treatment and whose artificial ulcer was closed using the SCCT were enrolled in this study. The technical success rate, number of clips for closure, procedure time, complication rate on the day of the procedure, clinical success rates on days 1 and 5, and incidence of severe stenosis of the gastrointestinal (GI) tract at 2 months after the procedure were evaluated., Results: The median ulcer diameter was 20 mm. The tumor locations were the stomach ( n = 19), jejunum ( n = 1), and colon ( n = 5). The technical success rate was 100% (25/25), and the rate of incomplete closure was 0% (0/25). Eight clips were needed on average. The median procedure time was 18 min (range 5-49 min). The complication rate was 0% (25/25). The clinical success rates on days 1 and 5 were 100% (19/19) and 100% (9/9), respectively. No patients presented stenosis as a late complication at 2 months after the procedure (0/25)., Conclusion: The SCCT could be applied in the treatment of artificial ulcers in several parts of the GI tract with a high clinical success rate and no complications. The SCCT appears to be a good option for closing artificial mucosal ulcers., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2020 by S. Karger AG, Basel.)

Hypoxia in adipose tissue is regarded as a trigger that induces dysregulation of the secretory profile in adipocytes. Similarly, local dysregulation of adipocytokine secretion is an initial event in the deleterious effects of obesity on metabolism. We previously reported that CXCL13 is highly produced during adipogenesis, however little is known about the roles of CXCL13 in adipocytes. Here, we found that hypoxia, as modeled by 1% O2 or exposure to the hypoxia-mimetic reagent desferrioxamine (DFO) has strong inductive effects on the expression of CXCL13 and CXCR5, a CXCL13 receptor, in both undifferentiated and differentiated adipocytes and in organ-cultured white adipose tissue (WAT). CXCL13 was also highly expressed in WAT from high fat diet-fed mice. Hypoxic profile, typified by increased expression of interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) and decreased expression of adiponectin, was significantly induced by CXCL13 treatment during adipogenic differentiation. Conversely, the treatment of adipocytes with a neutralizing-antibody against CXCL13 as well as CXCR5 knockdown by specific siRNA effectively inhibited DFO-induced inflammation. The phosphorylation of Akt2, a protective factor of adipose inflammation, was significantly inhibited by CXCL13 treatment during adipogenic differentiation. Mechanistically, CXCL13 induces the expression of PHLPP1, an Akt2 phosphatase, through focal adhesion kinase (FAK) signaling; and correspondingly we show that CXCL13 and DFO-induced IL-6 and PAI-1 expression was blocked by Phlpp1 knockdown. Furthermore, we revealed the functional binding sites of PPARγ2 and HIF1-α within the Cxcl13 promoter. Taken together, these results indicate that CXCL13 is an adipocytokine that facilitates hypoxia-induced inflammation in adipocytes through FAK-mediated induction of PHLPP1 in autocrine and/or paracrine manner., (© 2019 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Osteopontin (OPN) is an osteoblast-derived secretory protein that plays a role in bone remodeling, osteoblast responsiveness, and inflammation. We recently found that osteoblast differentiation is type-specific, with conditions of JNK inactivation inducing osteoblasts that preferentially express OPN (OPN-type). Since OPN-type osteoblasts highly express osteogenesis-inhibiting proteins and Rankl, an important inducer of osteoclastogenesis, an increased appearance of OPN-type osteoblasts may be associated with inefficient and poor-quality bone regeneration. However, whether specific osteogenic inducers can modulate OPN-type osteoblast differentiation is completely unknown. Here, we demonstrate that bone morphogenic protein 9 (BMP9) prevents induction of OPN-type osteoblast differentiation under conditions of JNK inhibition. Although JNK inactivation suppressed both BMP2- and BMP9-induced matrix mineralization and osteocalcin expression, the expression of Rankl and specific cytokines such as Gpha2, Esm1, and Sfrp1 under similar conditions was increased in all cells except those treated with BMP9. Increased expression of Id4, a critical transcriptional regulator of OPN-type osteoblast differentiation, was similarly prevented only in BMP9-treated cells. We also found that BMP9 specifically induces the expression of Hey1, a bHLH transcriptional repressor, and that Id4 inhibits the suppressive effects of Hey1 on Opn promoter activity by forming Id4-Hey1 complexes in osteoblasts. Using site-direct mutagenesis, ChIP, and immunoprecipitation, we elucidated that BMP9-induced overexpression of Hey1 can overcome the effects of Id4 and suppress OPN expression. We further found that p38 activation and JNK inactivation are involved in BMP9-induced Hey1 expression. Collectively, these data suggest that BMP9 is a unique osteogenic inducer that regulates OPN-type osteoblast differentiation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Bone morphogenetic protein (BMP)9 has been reported to be the most potent BMP to induce bone formation. However, the details of BMP9-transduced intracellular signaling remain ambiguous. Here, we have investigated signal transduction mechanisms of BMP9 in comparison to BMP2, another potent inducer of bone formation, in osteoblasts. In a mouse osteoblast cell line, BMP9 induced higher mRNA levels of alkaline phosphatase (ALP) and runt-related transcription factor 2 (Runx2) than BMP2 within 2 h. Unlike BMP2, BMP9 induced rapid phosphorylation of glycogen synthase kinase 3-β (GSK3-β) and protein kinase B (Akt) and increased the cellular protein content of β-catenin. BMP9 moderately increased mRNA levels of several canonical Wingless-related integration site to lower degrees than BMP2. Furthermore, BMP9-induced GSK3-β phosphorylation was not inhibited by pretreatment with actinomycin D, cycloheximide, or Brefeldin A, indicating it is independent of Wnt protein secretion. BMP9-induced GSK3-β phosphorylation was abrogated by Akt or class I PI3K-specific inhibitors. Moreover, inactivation of GSK3-β by LiCl did not further promote ALP and Runx2 mRNA induction by BMP9 as significantly as that by BMP2. Notably, BMP9-induced GSK3-β phosphorylation was inhibited by small interfering RNA against endoglin and GIPC PDZ domain-containing family, member 1. Taken together, our present findings have indicated that BMP9 directly activates GSK3β-β-catenin signaling pathway through class I PI3K-Akt Axis in osteoblasts, which may be essential for the potent osteoinductive activity of BMP9.-Eiraku, N., Chiba, N., Nakamura, T., Amir, M. S., Seong, C.-H., Ohnishi, T., Kusuyama, J., Noguchi, K., Matsuguchi, T. BMP9 directly induces rapid GSK3-β phosphorylation in a Wnt-independent manner through class I PI3K-Akt axis in osteoblasts.