Vanillin Promotes Osteoblast Differentiation, Mineral Apposition, and Antioxidant Effects in Pre-Osteoblasts

Antioxidant vanillin (4-hydroxy-3-methoxybenzaldehyde) is used as a flavoring in foods, beverages, and pharmaceuticals. Vanillin possesses various biological effects, such as antioxidant, anti-inflammatory, antibacterial, and anticancer properties. This study aimed to investigate the biological activities of vanillin purified from Adenophora triphylla var. japonica Hara on bone-forming processes. Vanillin treatment induced mineralization as a marker for mature osteoblasts, after stimulating alkaline phosphatase (ALP) staining and activity. The bone-forming processes of vanillin are mainly mediated by the upregulation of the bone morphogenetic protein 2 (BMP2), phospho-Smad1/5/8, and runt-related transcription factor 2 (RUNX2) pathway during the differentiation of osteogenic cells. Moreover, vanillin promoted osteoblast-mediated bone-forming phenotypes by inducing migration and F-actin polymerization. Furthermore, we validated that vanillin-mediated bone-forming processes were attenuated by noggin and DKK1. Finally, we demonstrated that vanillin-mediated antioxidant effects prevent the death of osteoblasts during bone-forming processes. Overall, vanillin has bone-forming properties through the BMP2-mediated biological mechanism, indicating it as a bone-protective compound for bone health and bone diseases such as periodontitis and osteoporosis.

Vitexicarpin Induces Apoptosis and Inhibits Metastatic Properties via the AKT-PRAS40 Pathway in Human Osteosarcoma

Osteosarcoma, which has poor prognosis after metastasis, is the most common type of bone cancer in children and adolescents. Therefore, plant-derived bioactive compounds are being actively developed for cancer therapy. Artemisia apiacea Hance ex Walp. is a traditional medicinal plant native to Eastern Asia, including China, Japan, and Korea. Vitexicarpin (Vitex), derived from A. apiacea, has demonstrated analgesic, anti-inflammatory, antitumour, and immunoregulatory properties; however, there are no published studies on Vitex isolated from the aerial parts of A. apiacea. Thus, this study aimed to evaluate the antitumour activity of Vitex against human osteosarcoma cells. In the present study, Vitex (>99% purity) isolated from A. apiacea induced significant cell death in human osteosarcoma MG63 cells in a dose- and time-dependent manner; cell death was mediated by apoptosis, as evidenced by the appearance of cleaved-PARP, cleaved-caspase 3, anti-apoptotic proteins (Survivin and Bcl-2), pro-apoptotic proteins (Bax), and cell cycle-related proteins (Cyclin D1, Cdk4, and Cdk6). Additionally, a human phosphokinase array proteome profiler revealed that Vitex suppressed AKT-dependent downstream kinases. Further, Vitex reduced the phosphorylation of PRAS40, which is associated with autophagy and metastasis, induced autophagosome formation, and suppressed programmed cell death and necroptosis. Furthermore, Vitex induced antimetastatic activity by suppressing the migration and invasion of MMP13, which is the primary protease that degrades type I collagen for tumour-induced osteolysis in bone tissues and preferential metastasis sites. Taken together, our results suggest that Vitex is an attractive target for treating human osteosarcoma.

Osteogenic Activities of Trifolirhizin as a Bioactive Compound for the Differentiation of Osteogenic Cells

Plant extracts are widely used as traditional medicines. Sophora flavescens Aiton-derived natural compounds exert various beneficial effects, such as anti-inflammatory, anticancer, antioxidant, and antiregenerative activities, through their bioactive compounds, including flavonoids and alkaloids. In the present study, we investigated the biological effects of an S. flavescens-derived flavonoid, trifolirhizin (trifol), on the stimulation of osteogenic processes during osteoblast differentiation. Trifol (>98% purity) was successfully isolated from the root of S. flavescens and characterized. Trifol did not exhibit cellular toxicity in osteogenic cells, but promoted alkaline phosphatase (ALP) staining and activity, with enhanced expression of the osteoblast differentiation markers, including Alp, ColI, and Bsp. Trifol induced nuclear runt-related transcription factor 2 (RUNX2) expression during the differentiation of osteogenic cells, and concomitantly stimulated the major osteogenic signaling proteins, including GSK3β, β-catenin, and Smad1/5/8. Among the mitogen-activated protein kinases (MAPKs), Trifol activated JNK, but not ERK1/2 and p38. Trifol also increased the osteoblast-mediated bone-forming phenotypes, including transmigration, F-actin polymerization, and mineral apposition, during osteoblast differentiation. Overall, trifol exhibits bioactive activities related to osteogenic processes via differentiation, migration, and mineralization. Collectively, these results suggest that trifol may serve as an effective phytomedicine for bone diseases such as osteoporosis.

Xanol Promotes Apoptosis and Autophagy and Inhibits Necroptosis and Metastasis via the Inhibition of AKT Signaling in Human Oral Squamous Cell Carcinoma

Angelica keiskei Koidzumi (A. keiskei) is used as a traditional medicine, anti-aging agent, and health food, as well as to restore vitality. Xanthoangelol (xanol), a prenylated chalcone, is the predominant constituent of A. keiskei. Oral squamous cell carcinoma (OSCC), the most common malignancy, has a high proliferation rate and frequent metastasis. However, it is unknown whether xanol has anti-OSCC effects on apoptosis, autophagy, and necroptosis. In the present study, we purified xanol from A. keiskei and demonstrated that it suppressed cell proliferation and induced cytotoxicity in human OSCC. Xanol triggered apoptotic cell death by regulating apoptotic machinery molecules but inhibited necroptotic cell death by dephosphorylating the necroptotic machinery molecules RIP1, RIP3, and MLKL in human OSCC. We also found that xanol inhibited the PI3K/AKT/mTOR/p70S6K pathway and induced autophagosome formation by enhancing beclin-1 and LC3 expression levels and reducing p62 expression levels. Furthermore, we showed that xanol prevented the metastatic phenotypes of human OSCC by inhibiting migration and invasion via the reduction of MMP13 and VEGF. Finally, we demonstrated that xanol exerted anticancer effects on tumorigenicity associated with its transformed properties. Taken together, these findings demonstrate the anticancer effects and biological mechanism of action of xanol as an effective phytomedicine for human OSCC.

Latifolin, a Natural Flavonoid, Isolated from the Heartwood of Dalbergia odorifera Induces Bioactivities through Apoptosis, Autophagy, and Necroptosis in Human Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant neoplasm with frequent metastasis and high mortality in the oral cavity. Plant-derived natural compounds are actively progressing as a trend for cancer treatment. Latifolin (Latif), is a natural flavonoid isolated from the heartwood of Dalbergia odorifera T. Chen (D. odorifera) has been known to have beneficial effects on anti-aging, anti-carcinogenic, anti-inflammatory, and cardio-protective activities. However, the anti-cancer effects of Latif are unknown in OSCC. Herein, as a result of analysis in terms of the aggressive features of OSCCs, we found that Latif significantly inhibited the cell proliferation of human YD-8 and YD-10B OSCCs, and caused the anti-metastatic activities by effectively blocking cell migration, invasion, and adhesion via the inactivation of focal adhesion kinase (FAK)/non-receptor tyrosine kinase (Src). Moreover, we found that Latif induced apoptotic cell death to suppress the cell survival and proliferation of YD-10B OSCCs by targeting PI3K/AKT/mTOR/p70S6K signaling. Finally, we analyzed in terms of autophagy and necroptosis, which are other mechanisms of programmed cell death and survival compared to apoptosis in YD-10B OSCCs. We found that Latif suppressed autophagic-related proteins and autophagosome formation, and also Latif inhibited necroptosis by dephosphorylating necroptosis-regulatory proteins (RIP1, RIP3, and MLKL). Given these findings, our results provided new evidence for Latif's biological effect and mechanism in YD-10B OSCCs, suggesting that Latif may be a new candidate for patients with OSCCs.

Suffruticosol B Is an Osteogenic Inducer through Osteoblast Differentiation, Autophagy, Adhesion, and Migration

Suffruticosol B (Suf-B) is a stilbene found in Paeonia suffruticosa ANDR., which has been traditionally used in medicine. Stilbenes and their derivatives possess various pharmacological effects, such as anticancer, anti-inflammatory, and anti-osteoporotic activities. This study aimed to explore the bone-forming activities and mechanisms of Suf-B in pre-osteoblasts. Herein, >99.9% pure Suf-B was isolated from P. suffruticosa methanolic extracts. High concentrations of Suf-B were cytotoxic, whereas low concentrations did not affect cytotoxicity in pre-osteoblasts. Under zero levels of cytotoxicity, Suf-B exhibited bone-forming abilities by enhancing alkaline phosphatase enzyme activities, bone matrix calcification, and expression levels with non-collagenous proteins. Suf-B induces intracellular signal transduction, leading to nuclear RUNX2 expression. Suf-B-stimulated differentiation showed increases in autophagy proteins and autophagosomes, as well as enhancement of osteoblast adhesion and transmigration on the ECM. These results indicate that Suf-B has osteogenic qualities related to differentiation, autophagy, adhesion, and migration. This also suggests that Suf-B could have a therapeutic effect as a phytomedicine in skeletal disorders.

Chi3L1 is a therapeutic target in bone metabolism and a potential clinical marker in patients with osteoporosis

BMP2 is clinically used as an ectopic bone inducer and plays a significant role in bone development, formation, and diseases. Chitinase 3-like 1 protein (Chi3L1) is found in the skeletal system. However, Chi3L1-mediated bone metabolism and aging-related bone erosion via BMP2 signaling have not yet been demonstrated. Herein, Chi3L1 increased BMP2-induced osteoblast differentiation in mesenchymal precursor cells and human primary osteoblasts. Chi3L1^KO(-/-) showed abnormal bone development, and primary osteoblasts isolated from Chi3L1^KO(-/-) exhibited impaired osteoblast differentiation and maturation. Chi3L1 also potentiated BMP2 signaling and RUNX2 expression in primary osteoblasts. Chi3L1 interacted with BMPRIa, which increased the surface expression of BMPRIa and promoted BMP2 signaling to induce osteoblast differentiation. Chi3L1^KO(-/-) mice showed bone formation reduced with a decrease in RUNX2 expression in calvarial defects. Chi3L1^KO(-/-) mice exhibited aging-related osteoporotic bone loss with decreases in the levels of RUNX2 and OPG, while serum PYD level and osteoclast number increased. Chi3L1 increased OPG via non-canonical BMP2 signaling in osteoblasts, which suppressed osteoclastogenesis in BMMs. Furthermore, ROC analysis showed that serum Chi3L1 level clinically decreased in osteoporosis patients. Our findings demonstrate that Chi3L1 promotes bone formation, suppresses osteoclastogenesis, and prevents aging-related osteoporosis.

Effects of Scoparone on differentiation, adhesion, migration, autophagy and mineralization through the osteogenic signalling pathways

Scoparone (SCOP), an active and efficient coumarin compound derived from Artemisia capillaris Thunb, has been used as a traditional Chinese herbal medicine. Herein, we investigated the effects of SCOP on the osteogenic processes using MC3T3‐E1 pre‐osteoblasts in in vitro cell systems. SCOP (C₁₁H₁₀O₄, > 99.17%) was purified and identified from A. capillaries. SCOP (0.1 to 100 μM concentrations) did not have cytotoxic effects in pre‐osteoblasts; however, it promoted alkaline phosphatase (ALP) staining and activity, and mineralized nodule formation under early and late osteogenic induction. SCOP elevated osteogenic signals through the bone morphogenetic protein 2 (BMP2)‐Smad1/5/8 pathway, leading to the increased expression of runt‐related transcription factor 2 (RUNX2) with its target protein, matrix metallopeptidase 13 (MMP13). SCOP also induced the non‐canonical BMP2‐MAPKs pathway, but not the Wnt3a‐β‐catenin pathway. Moreover, SCOP promoted autophagy, migration and adhesion under the osteogenic induction. Overall, the findings of this study demonstrated that SCOP has osteogenic effects associated with cell differentiation, adhesion, migration, autophagy and mineralization.

Paeoniflorigenone regulates apoptosis, autophagy, and necroptosis to induce anti-cancer bioactivities in human head and neck squamous cell carcinomas

ETHNOPHARMACOLOGICAL RELEVANCE

Paonia suffruticosa Andr. belonging to the family Paeoniaceae and has been used as a medicinal plant in Asian countries including China, Korea, and Japan. The roots of P. suffruticosa has been used in traditional medicine in various diseases including cancer and cardiovascular, female genital, and inflammatory diseases.

AIM OF THE STUDY

Head and neck squamous cell carcinomas (HNSCCs) pathologically account for 90% of all head and neck cancers. However, effective targeted therapies for HNSCCs are insufficient and the prognosis is very poor, especially in patients with metastatic HNSCCs. To overcome the current limitations of available therapies for HNSCCs, pathological approaches using natural compounds are attracting attention. Our study aimed to demonstrate the anti-cancer effects of paeoniflorigenone (Paeo, 98.9% purity) isolated from the root bark of P. suffruticosa.

MATERIALS AND METHODS

Our scientific methodology was performed as follows: cytotoxicity, morphological changes, and apototic DNA fragmentation were analyzed using MTT, light microscopy, and TUNEL assays. Protein expression, apoptosis, necroptosis, and autophagy were analyzed using Western blot and immunofluorescence assays. Cell migration and invasion were analyzed using wound healing and Boyden chamber assays.

RESULTS

We demonstrated that Paeo significantly reduced cell proliferation and cell division, leading to caspase-dependent apoptotic cell death in human YD-10B HNSCC cells. This result was associated with PI3K/AKT/mTOR/p70S6K signaling in these cells. In addition, we investigated other programmed cell death mechanisms associated with apoptosis and found that Paeo inhibited necroptosis via dephosphorylation of key necroptotic proteins (RIP and MLKL), whereas Paeo induced autophagy via increased LC3I/II expression and autophagosome formation in human YD-10B HNSCC cells. The anti-metastatic effects of Paeo significantly suppressed cell migration and invasion in human YD-10B HNSCC cells.

CONCLUSION

Overall, our results demonstrated that the bioactive compound, Paeo, exhibited anti-cancer bioactivities in human YD-10B HNSCC cells, suggesting that Paeo may be an attractive pathological approach for patients with human HNSCCs.

Falcarindiol Stimulates Apoptotic and Autophagic Cell Death to Attenuate Cell Proliferation, Cell Division, and Metastasis through the PI3K/AKT/mTOR/p70S6K Pathway in Human Oral Squamous Cell Carcinomas

Human oral squamous cell carcinomas (OSCCs) have high cancer mortality and a 5-year survival rate lower than that of most other carcinomas. New therapeutic strategies are required for the treatment and prevention against OSCCs. An approach to cancer therapy using plant-derived natural compounds has been actively in progress as a trend. Falcarindiol (FALC), or its isolated form Ostericum koreanum Kitagawa (O. koreanum), is present in many food and dietary plants, especially in carrots, and this compound has a variety of beneficial effects. However, biological activity of FALC has not been reported in OSCCs yet. This study aimed to demonstrate the antitumor effects of FALC against OSCCs, YD-10B cells. In this study, FALC was selected as a result of screening for compounds isolated from various natural products in YD-10B cells. FALC suppressed cell growth, and FALC-induced apoptotic cell death was mainly accompanied by the dephosphorylation of PI3K, AKT, mTOR, and p70S6K. The apoptotic cell death was also associated with autophagy as evidenced by the expression of Beclin-1, the conversion of LC3-II, and the formation of autophagosome. FALC-induced autophagy was accompanied by MAPKs including ERK1/2 and p38. Furthermore, FALC caused the antimetastatic effects by inhibiting the migration and invasion of YD-10B cells. Taken together, the findings suggest the potential value of FALC as a novel candidate for therapeutic strategy against OSCCs.

Calycosin-7-O-β-Glucoside Isolated from Astragalus membranaceus Promotes Osteogenesis and Mineralization in Human Mesenchymal Stem Cells

Stem cells have received attention in various diseases, such as inflammatory, cancer, and bone diseases. Mesenchymal stem cells (MSCs) are multipotent stem cells that are critical for forming and repairing bone tissues. Herein, we isolated calycosin-7-O-β-glucoside (Caly) from the roots of Astragalus membranaceus, which is one of the most famous medicinal herbs, and investigated the osteogenic activities of Caly in MSCs. Caly did not affect cytotoxicity against MSCs, whereas Caly enhanced cell migration during the osteogenesis of MSCs. Caly increased the expression and enzymatic activities of ALP and the formation of mineralized nodules during the osteogenesis of MSCs. The osteogenesis and bone-forming activities of Caly are mediated by bone morphogenetic protein 2 (BMP2), phospho-Smad1/5/8, Wnt3a, phospho-GSK3β, and phospho-AKT, inducing the expression of runt-related transcription factor 2 (RUNX2). In addition, Caly-mediated osteogenesis and RUNX2 expression were attenuated by noggin and wortmannin. Moreover, the effects were validated in pre-osteoblasts committed to the osteoblast lineages from MSCs. Overall, our results provide novel evidence that Caly stimulates osteoblast lineage commitment of MSCs by triggering RUNX2 expression, suggesting Caly as a potential anabolic drug to prevent bone diseases.

Anti-tumor effects of jaceosidin on apoptosis, autophagy, and necroptosis in human glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most aggressive and common malignant neoplasm. Nevertheless, a 5-year survival rate of patients with GBM has remained below 5%. Artemisia princeps PAMPANINI, used as a food and traditional medicine, have shown beneficial properties including anti-inflammatory, anti-oxidative, and anti-cancer activities. Thus, this study aimed to investigate biological mechanism of a bioactive compound, jaceosidin (JAC), isolated from A. princeps in human GBM T98G cells. Herein, as a result of analysis in terms of cancer survival and death, we found that JAC significantly reduced cell survival against T98G cells. In addition, JAC increased apoptotic cell death via changes on morphological and molecular phenotypes in T98G cells as evidenced by cellular shapes and DNA fragmentation. The apoptotic cell death was confirmed by the cleavage of caspase-3 and PARP, the downregulation of survivin and Bcl-2. Moreover, JAC decreased the expression of cyclinD1 and Cdks and increased the phosphorylation of EKR, JNK, and p38 MAPKs. Specifically, JAC suppressed the PI3K/AKT signaling and its downstream molecules including p70S6, GSK3β, and β-catenin. In addition, as a result of analysis in terms of metastasis using wound healing and Boyden chamber assays, JAC showed anti-migrative and anti-invasive activities. Finally, we analyzed in terms of autophagy and necroptosis that are modes of programmed cell survival and death different from apoptosis in T98G cells. We found that JAC inhibited autophgic regulatory proteins including Beclin-1, Atgs, and LC3A/B, thereby reducing autophagic-mediated cell survival, whereas JAC did not affect phosphorylation of key proteins in necroptosis, especially MLKL. Given these findings, our results provided novel evidences on the biological mechanisms of JAC in T98G cells, suggesting that JAC may be a therapeutic agent for patients with GBM.

Anti-cancer effects of Hederoside C, a pentacyclic triterpene saponin, through the intrinsic apoptosis and STAT3 signaling pathways in osteosarcoma

Natural compounds have emerged as an approach in cancer therapy. Pulsatilla koreana Nakai is used as a traditional medicinal plant that found throughout China and Korea. However, anti-cancer effects of Hederoside C (HedC) isolated from P. koreana has not been investigated in osteosarcoma. The present study aimed to demonstrate anti-cancer functions of HedC against human osteosarcoma cells. Herein, we found that HedC suppressed the proliferation of MG63 cells and U2OS cells in the dose- and time-dependent manner, and caused intrinsic apoptosis pathways as evidenced by morphological changes, TUNEL-positive cells, cleaved-PARP, and cleaved-caspase 9 and 3. HedC increased p53, Bax, and p21, whereas HedC reduced Bcl-2. HedC-mediated apoptosis was accompanied by decreases in the mitogen-activated protein kinases (MAPKs) and STAT3 phosphorylation. Wound healing and Boyden chamber assays also showed the anti-metastatic effects of HedC by suppressing migration and invasion. In addition, the anti-cancer effects of HedC were observed in in vivo xenograft mice model, and HedC treatment induced the decreased PCNA and p-STAT3 as well as the increased p53 and cleaved caspase-3. Taken together, our results provide evidence that HedC might be an attractive therapeutic strategy against osteosarcoma.

Paeonolide as a Novel Regulator of Core-Binding Factor Subunit Alpha-1 in Bone-Forming Cells

Paeonia suffruticosa has been extensively used as a traditional medicine with various beneficial effects; paeonolide (PALI) was isolated from its dried roots. This study aimed to investigate the novel effects and mechanisms of PALI in pre-osteoblasts. Here, cell viability was evaluated using an MTT assay. Early and late osteoblast differentiation was examined by analyzing the activity of alkaline phosphatase (ALP) and by staining it with Alizarin red S (ARS). Cell migration was assessed using wound healing and Boyden chamber assays. Western blot and immunofluorescence analyses were used to examine the intracellular signaling pathways and differentiation proteins. PALI (0.1, 1, 10, 30, and 100 μM) showed no cytotoxic or proliferative effects in pre-osteoblasts. In the absence of cytotoxicity, PALI (1, 10, and 30 μM) promoted wound healing and transmigration during osteoblast differentiation. ALP staining demonstrated that PALI (1, 10, and 30 μM) promoted early osteoblast differentiation in a dose-dependent manner, and ARS staining showed an enhanced mineralized nodule formation, a key indicator of late osteoblast differentiation. Additionally, low concentrations of PALI (1 and 10 μM) increased the bone morphogenetic protein (BMP)–Smad1/5/8 and Wnt–β-catenin pathways in osteoblast differentiation. Particularly, PALI (1 and 10 μM) increased the phosphorylation of ERK1/2 compared with BMP2 treatment, an FDA-approved drug for bone diseases. Furthermore, PALI-mediated early and late osteoblast differentiation was abolished in the presence of the ERK1/2 inhibitor U0126. PALI-induced RUNX2 (Cbfa1) expression and nuclear localization were also attenuated by blocking the ERK1/2 pathway during osteoblast differentiation. We suggest that PALI has biologically novel activities, such as enhanced osteoblast differentiation and bone mineralization mainly through the intracellular ERK1/2-RUNX2 signaling pathway, suggesting that PALI might have therapeutic action and aid the treatment and prevention of bone diseases, such as osteoporosis and periodontitis.

Ziyuglycoside I Upregulates RUNX2 through ERK1/2 in Promoting Osteoblast Differentiation and Bone Mineralization

Sanguisorba officinalis L. (Rosaceae) is a perennial herbaceous plant and its roots have been used as an important traditional medicine for over 2000 years. Ziyuglycoside I (Ziyu), an active compound isolated from the roots of S. officinalis L., has shown biological effects such as anti-oxidant, antiviral, and antiwrinkle activities. This study aimed to elucidate the underlying mechanisms of action of Ziyu on cytotoxicity, migration, and differentiation of pre-osteoblasts. Herein, at concentrations ranging from 1 to 100 [Formula: see text]M, Ziyu was not cytotoxic against pre-osteoblasts. Alkaline phosphatase activity assay and staining, and migration assay showed that Ziyu increased cell migration and promoted early osteoblast differentiation, followed by the enhancement of mineralized nodule formation in a dose-dependent manner, as indicated by Alizarin Red S staining. In addition, Ziyu increased the protein levels of runt-related transcription factor 2 (RUNX2) during osteoblast differentiation, whereas it did not affect the phosphorylation of Smad1/5/8 and GSK3b and expression of [Formula: see text]-catenin. Ziyu also activated ERK1/2 and mitogen-activated protein kinase during osteoblast differentiation, and ERK1/2 inhibitor attenuated Ziyu-mediated RUNX2 expression and nuclear accumulation. Furthermore, Ziyu-mediated early and late osteoblast differentiation was significantly suppressed by the inhibition of ERK1/2, which was accompanied by attenuation in the mRNA levels of osteoblast-related genes including bone sialoprotein, osteopontin, and osteocalcin. Taken together, the findings of this study provide evidence that Ziyu promotes cell migration, osteoblast differentiation, and bone mineralization and suggest a potential role for Ziyu in the treatment of bone diseases.

11-O-Galloyl Bergenin from Corylopsis coreanas Leaves Induces Autophagy and Apoptosis in Human Osteosarcoma

Osteosarcoma is the most common malignant bone-forming tumor, wherein most patients with high grade osteosarcomas are treated with chemotherapy. Despite this, survival for metastatic or relapsed osteosarcoma patients has remained at an overall 5-year survival rate of 20%. In particular, the extracts of Corylopsis coreana (Korean winter hazel), a cultivated woody plant in South Korea, have shown beneficial anti-inflammatory, anti-oxidative, anti-osteoclastic, and antihyperuricemic properties. Therefore, this study aimed to demonstrate the antitumor activities and underlying mechanism of 11-O-Galloyl bergenin (OGAL) isolated from Corylopsis coreanas leaves in human osteosarcoma cells. Herein, we found that OGAL inhibited MG63 cell proliferation and induced cellular apoptosis as evidenced by cleaved-PARP, cleaved-caspase 3, TUNEL-positive cells, and Annexin V-positive cells. Specifically, OGAL-induced apoptosis was accompanied by p53 and p21 upregulation, BAX expression, and decreased Bcl-2 and cdk2. Moreover, OGAL induced autophagy via AKT inactivation, LC3II upregulation, and MG63 cell autophagosome formation. OGAL-induced autophagy was also accompanied by increased p38 phosphorylation, whereas JNK and ERK1/2 activities were found to be unaffected upon examining the MAPK signaling pathway. Furthermore, wound healing and Boyden chamber assays showed that OGAL suppressed MG63 cell migration and invasion. Given these findings, this study provided evidence that OGAL has antitumor effects by apoptosis and autophagy enhancement through increased p53, AKT, and p38 signaling, suggesting that OGAL may be a potential therapeutic strategy for osteosarcoma treatment.

Effects of the amide alkaloid piperyline on apoptosis, autophagy, and differentiation of pre-osteoblasts

BACKGROUND

Amide alkaloidsare typical constituents in plants of the Piperaceae family. Most of the pharmacological properties of Piper nigrum L. are attributed to the major amide alkaloid, piperine. Piperyline (PIPE) is a further amide alkaloid that has been isolated from P. nigrum.

HYPOTHESIS/PURPOSE

This study was performed to examine the biological effects of PIPE on pre-osteoblasts and elucidate the underlying mechanisms.

STUDY DESIGN

We investigated the effects of PIPE in MC3T3E-1 cells, which are widely used for studying osteoblast behavior in in vitro cell systems.

METHODS

We evaluated cell viability based on the MTT assay, apoptosis by TUNEL staining, adhesion and migration by cell adhesion and migration assays, and osteoblast differentiation by alkaline phosphatase activity and staining. Western blot and immunocytochemical analyses were used to investigate cell signaling pathways.

RESULTS

We found that at concentrations ranging from 1 to 30 μM, PIPE inhibited cell growth and induced apoptosis in pre-osteoblasts, which was accompanied by the upregulation of apoptotic proteins but downregulation of anti-apoptotic proteins. In contrast, PIPE had no appreciable effect on the autophagy pathway. Nevertheless, PIPE reduced cell adhesion and migration via the inactivation of non-receptor tyrosine kinase (Src)/focal adhesion kinase (FAK) and mitogen-activated protein kinases, and also promoted the downregulation of matrix metalloproteinase 2 and 9 levels. Furthermore, at concentrations of 10 and 30 μM, PIPE suppressed osteoblast differentiation, as indicated by reductions in alkaline phosphatase staining and activity. In addition, PIPE reduced the protein levels of phospho-Smad1/5/8 and runt-related transcription factor 2, and the mRNA levels of osteopontin, alkaline phosphatase, and osteocalcin.

CONCLUSION

The findings of this study indicate that PIPE has biological effects associated with cell adhesion, migration, proliferation, and osteoblast differentiation, and suggest a potential role for this alkaloid in the treatment of bone diseases.

Prevention of multiple system atrophy using human bone marrow-derived mesenchymal stem cells by reducing polyamine and cholesterol-induced neural damages

Background

Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder of unknown etiology, but is closely associated with damage to dopaminergic neurons. MSA progression is rapid. Hence, long-term drug treatments do not have any therapeutic benefits. We assessed the inhibitory effect of mesenchymal stem cells (MSCs) on double-toxin-induced dopaminergic neurodegenerative MSA.

Results

Behavioral disorder was significantly improved and neurodegeneration was prevented following MSC transplantation. Proteomics revealed lower expression of polyamine modulating factor-binding protein 1 (PMFBP1) and higher expression of 3-hydroxymethyl-3-methylglutaryl-CoA lyase (HMGCL), but these changes were reversed after MSC transplantation. In the in vitro study, the 6-OHDA-induced effects were reversed following co-culture with MSC. However, PMFBP1 knockdown inhibited the recovery effect due to the MSCs. Furthermore, HMGCL expression was decreased following co-culture with MSCs, but treatment with recombinant HMGCL protein inhibited the recovery effects due to MSCs.

Conclusions

These data indicate that MSCs protected against neuronal loss in MSA by reducing polyamine- and cholesterol-induced neural damage.

Chitinase 3 like 1 suppresses the stability and activity of p53 to promote lung tumorigenesis

Background

Chitinase 3 like 1 protein (Chi3L1) is expressed in several cancers, and a few evidences suggest that the secreted Chi3L1 contributes to tumor development. However, the molecular mechanisms of intracellular Chi3L1 are unknown in the lung tumor development. Methods: In the present study, we generated Chi3L1 knockout mice (Chi3L1^KO(−/−)) using CRISPR/Cas9 system to investigate the role of Chi3L1 on lung tumorigenesis.

Results

We established lung metastasis induced by i.v. injections of B16F10 in Chi3L1^KO(−/−). The lung tumor nodules were significantly reduced in Chi3L1^KO(−/−) and protein levels of p53, p21, BAX, and cleaved-caspase 3 were significantly increased in Chi3L1^KO(−/−), while protein levels of cyclin E1, CDK2, and phsphorylation of STAT3 were decreased in Chi3L1^KO(−/−). Allograft mice inoculated with B16F10 also suppressed tumor growth and increased p53 and its target proteins including p21 and BAX. In addition, knockdown of Chi3L1 in lung cancer cells inhibited lung cancer cell growth and upregulated p53 expression with p21 and BAX, and a decrease in phosphorylation of STAT3. Furthermore, we found that intracellular Chi3L1 physically interacted and colocalized with p53 to inhibit its protein stability and transcriptional activity for target genes related with cell cycle arrest and apoptosis. In lung tumor patient, we clinically found that Chi3L1 expression was upregulated with a decrease in p53 expression, as well as we validated that intracellular Chi3L1 was colocalized, reversely expressed, and physically interacted with p53, which results in suppression of the expression and function of p53 in lung tumor patient.

Conclusions

Our studies suggest that intracellular Chi3L1 plays a critical role in the lung tumorigenesis by regulating its novel target protein, p53 in both an in vitro and in vivo system.

G721-0282 inhibits cell growth and induces apoptosis in human osteosarcoma through down-regulation of the STAT3 pathway

Osteosarcoma (OS) is considered the most common type of primary malignant bone tumor, which has an urgent need for more effective treatment. Recently, chitinase 3 like 1 (Chi3L1) expression has been found in a variety of cancer cells. However it is not known whether Chi3L1 regulates the STAT3 pathway in OS cells. Herein, we examined the effects of the G721-0282, a ligand of Chi3L1, in vitro and in vivo against OS cells. G721-0282 inhibited the proliferation of OS cells and induced apoptosis. This apoptosis was accompanied by upregulation of apoptotic proteins (PARP and procaspase-3), but downregulation of anti-apoptotic proteins (Survivin and Bcl-2). G721-0282 induced the inactivation of mitogen-activated protein kinases (MAPKs) with a decrease in the phosphorylation of Src and STAT3 in OS cells. Importantly, overexpression of Chi3L1 potentiated the effects of G721-0282, while knockdown of Chi3L1 attenuated the effects of G721-0282. Docking model study also showed that G721-0282 interacted with Chi3L1. In addition, G721-0282 inhibited cell migration, invasion, and colony formation. Furthermore, the anti-tumor effects of G721-0282 were observed in an xenograft in vivo model in association with the reduced expression of Chi3L1, PCNA, Cyclin D1, p-STAT3, as well as the increased expression of Chi3L1 was correlated with the p-STAT3 level in human bone tumor tissues. Taken together, a Chi3L1 ligand, G721-0282 may be an attractive therapeutic strategy for OS, especially in vitro and in vivo anti-proliferative effects against OS cells through the inhibition of the STAT3 pathway, and suggest the potentially therapeutic application of G721-0282 in the treatment of OS.

Peroxiredoxin 6 Inhibits Osteogenic Differentiation and Bone Formation Through Human Dental Pulp Stem Cells and Induces Delayed Bone Development

Aims: Peroxiredoxins (PRDXs) are thiol-specific antioxidant enzymes that regulate redox balance that are critical for maintaining the cellular potential for self-renewal and stemness. Stem cell-based regenerative medicine is a promising approach in tissue reconstruction. However, to obtain functional cells for use in clinical applications, stem cell technology still requires improvements. Results: In this study, we found that PRDX6 levels were decreased during osteogenic differentiation in human dental pulp stem cells (hDPSCs). hDPSCs stably expressing Myc-PRDX6 (hDPSC/myc-PRDX6) inhibited cell growth in hDPSCs during osteogenic differentiation and impaired osteogenic phenotypes such as alkaline phosphatase (ALP) activity, mineralized nodule formation, and osteogenic marker genes [ALP and osteocalcin (OCN)]. hDPSC cell lines stably expressing mutant glutathione peroxidase (PRDX6(C47S)) and independent phospholipase A2 (PRDX6(S32A)) were also generated. Each mutant form of PRDX6 abolished the impaired osteogenic phenotypes, the transforming growth factor-β-mediated Smad2 and p38 pathways, and RUNX2 expression. Furthermore, in vivo experiments revealed that hDPSC/myc-PRDX6 suppressed hDPSC-based bone regeneration in calvarial defect mice, and newborn PRDX6 transgenic mice exhibited delayed bone development and reduced RUNX2 expression. Innovation and Conclusion: These findings illuminate the effects of PRDX6 during osteogenic differentiation of hDPSCs, and also suggest that regulating PRDX6 may improve the clinical utility of stem cell-based regenerative medicine for the treatment of bone diseases. Antioxid. Redox Signal. 30, 1969-1982.

RANKL-induced osteoclastogenesis in bone marrow-derived macrophages is suppressed by cisapride

Cisapride is a selective 5-hydroxytryptamine (5-HT)₄ receptor (5-HT₄R) agonist. However, the effects of cisapride on osteoclasts and osteoblasts have not been fully explored. We therefore examined the effects of cisapride on osteoclastogenesis in cultured primary bone marrow-derived macrophages (BMMs), and on osteoblast differentiation in cultured primary calvarial pre-osteoblasts. Cisapride significantly inhibited tartrate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts and F-actin ring formation during receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. No cytotoxicity was observed. Cisapride also suppressed RANKL-induced expression of NF-ATc1, TRAP, and cathepsin K genes in BMMs. In addition, cisapride significantly stimulated apoptotic cell death of osteoclasts. However, cisapride had no effect on osteoblast differentiation, as assessed by alkaline phosphatase (ALP) activity and mineralized nodule formation in the cultured primary pre-osteoblasts. Overall, our findings suggest that cisapride may improve the clinical management of metabolic bone diseases such as osteoporosis.

Loss of parkin reduces lung tumor development by blocking p21 degradation

Several epidemiological studies have demonstrated the reciprocal relationship between the development of cancer and Parkinson’s disease (PD). However, the possible mechanisms underlying this relationship remain unclear. To identify this relationship, we first compared lung tumor growth in parkin knockout (KO) mice and wild-type (WT) mice. Parkin KO mice showed decreased lung tumor growth and increased expression of p21, a cell cycle arrester, as compared with WT mice. We also found that parkin interacts with p21, resulting in its degradation; however, parkin KO, knockdown, as well as mutation (R275W or G430D) reduced the degradation of p21. We investigated whether parkin KO increases the association of p21 with proliferating cell nuclear antigen (PCNA) or CDK2 by reducing p21 degradation, and, thus, arresting the cell cycle. The interaction between p21 and PCNA or CDK2 was also enhanced by parkin knockdown, and this increased interaction induced sub G0/G1 arrest, leading to cell death. Therefore, our data indicate that parkin KO reduces the development of lung tumors via cell cycle arrest by blocking the degradation of p21. These findings suggest that PD could be associated with lower lung cancer incidence.

Tectorigenin Promotes Osteoblast Differentiation and in vivo Bone Healing, but Suppresses Osteoclast Differentiation and in vivo Bone Resorption

Although tectorigenin (TG), a major compound in the rhizome of Belamcanda chinensis, is conventionally used for the treatment of inflammatory diseases, its effects on osteogenesis and osteoclastogenesis have not been reported. The objective of this study was to investigate the effects and possible underlying mechanism of TG on in vitro osteoblastic differentiation and in vivo bone formation, as well as in vitro osteoclast differentiation and in vivo bone resorption. TG promoted the osteogenic differentiation of primary osteoblasts and periodontal ligament cells. Moreover, TG upregulated the expression of the BMP2, BMP4, and Smad-4 genes, and enhanced the expression of Runx2 and Osterix. In vivo studies involving mouse calvarial bone defects with μCT and histologic analysis revealed that TG significantly increased new bone formation. Furthermore, TG treatment inhibited osteoclast differentiation and the mRNA levels of osteoclast markers. In vivo studies of mice demonstrated that TG caused the marked attenuation of bone resorption. These results collectively demonstrated that TG stimulated osteogenic differentiation in vitro, increased in vivo bone regeneration, inhibited osteoclast differentiation in vitro, and suppressed inflammatory bone loss in vivo. These novel findings suggest that TG may be useful for bone regeneration and treatment of bone diseases.

Dysregulation of 5-hydroxytryptamine 6 receptor accelerates maturation of bone-resorbing osteoclasts and induces bone loss

Rationale: Characterizing the regulation of bone-resorbing osteoclasts is central to the understanding of the pathogenesis and treatment of bone diseases, such as osteoporosis and periodontitis. 5-hydroxytryptamine (5-HT) has drawn considerable attention for its role in bone; however, it remains unknown whether the intracellular signaling of 5-HT receptors (5-HTRs) is linked to any of the regulatory mechanisms in osteoclasts. Herein, we report 5-HT₆R to be a key regulatory receptor for osteoclastogenesis.

Methods: In order to explore the critical role of 5-HT₆R in bone-resorbing osteoclasts, in vitro experiments were performed using mouse whole bone marrow cells isolated from femora and tibiae and In vivo animal experiments were performed using 5-HT₆R-deficient (5-HT₆R^KO-/-) mice, bone resorption mice model, and osteoporosis mice model.

Results: Compared to other 5HTRs, activation of 5-HT₆R relatively increased TRAP (tartrate-resistant acid phosphatase) activity during osteoclastogenesis. 5-HT₆R^KO(-/-) mice and 5-HT₆R^KO(-/-) osteoclast lineages presented with an abnormal phenotype and impaired osteoclastogenesis and impaired osteoclastogenesis. Activation of 5-HT₆R increased the number of TRAP-positive multinuclear osteoclasts, actin ring formation, and expression of early osteoclast markers with osteoclast lineage commitment. Intracellular 5-HT₆R signaling was found to be linked to RhoA GTPase activation and was involved in the maturation of osteoclasts. This signaling pathway also showed enhanced bone destruction after lipopolysaccharide (LPS) administration in mice. Furthermore, inhibition of 5-HT₆R-mediated RhoA GTPase signaling protected against ovariectomy(OVX)-induced bone loss in mice.

Conclusion: Taken together, our findings place the 5-HT₆R system in a new context of osteoclast lineages in both an in vitro and in vivo system, and also it may offer a novel molecular target for the treatment of bone diseases.

Xerogel Interfaced Nanofibers Stimulate Bone Regeneration Through the Activation of Integrin and Bone Morphogenetic Protein Pathways

A xerogel was interfaced onto biopolymer nanofibers though a core–shell electrospinning design for bone regeneration. The xerogel-interfaced biopolymer nanofibrous matrix was bioactive and highly hydrophilic, with a significant decrease in the water contact angle. The matrix showed excellent in vitro responses of primary osteoblasts in terms of adhesion, proliferation, and migration. Furthermore, the osteoblastic differentiation of cells, including alkaline phosphatase activity, mineralization, and gene expression, was significantly upregulated by the xerogel interface. In vivo animal tests in a critical-sized calvarial defect confirmed the new bone formation ability of the xerogel-surfaced nanofiber matrices. The underlying signaling mechanisms of the stimulation were implied to be integrin and bone morphogenetic protein (BMP) pathways, as demonstrated by the activation of integrin (α2β1) and downstream signaling molecules (FAK, paxillin, RhoA, MAPK, and NF-κB), as well as the BMPs and the downstream transcription factor Smad1/5/8. Taking these findings together, the xerogel-surfaced biopolymer nanofibers are proposed to be a promising scaffold candidate for bone regeneration.

Presenilin Mutation Suppresses Lung Tumorigenesis via Inhibition of Peroxiredoxin 6 Activity and Expression

Some epidemiological studies suggest an inverse correlation between cancer incidence and Alzheimer's disease (AD). In this study, we demonstrated experimental evidences for this inverse relationship. In the co-expression network analysis using the microarray data and GEO profile of gene expression omnibus data analysis, we showed that the expression of peroxiredoxin 6 (PRDX6), a tumor promoting protein was significantly increased in human squamous lung cancer, but decreased in mutant presenilin 2 (PS2) containing AD patient. We also found in animal model that mutant PS2 transgenic mice displayed a reduced incidence of spontaneous and carcinogen-induced lung tumor development compared to wildtype transgenic mice. Agreed with network and GEO profile study, we also revealed that significantly reduced expression of PRDX6 and activity of iPLA2 in these animal models. PS2 mutations increased their interaction with PRDX6, thereby increasing iPLA2 cleavage via increased γ-secretase leading to loss of PRDX6 activity. However, knockdown or inhibition of γ-secretase abolished the inhibitory effect of mutant PSs. Moreover, PS2 mutant skin fibroblasts derived from patients with AD showed diminished iPLA2 activity by the elevated γ-secretase activity. Thus, the present data suggest that PS2 mutations suppress lung tumor development by inhibiting the iPLA2 activity of PRDX6 via a γ-secretase cleavage mechanism and may explain the inverse relationship between cancer and AD incidence.

5-Hydroxytryptamine 6 Receptor (5-HT6R)-Mediated Morphological Changes via RhoA-Dependent Pathways

The 5-HT6R has been considered as an attractive therapeutic target in the brain due to its exclusive expression in the brain. However, the mechanistic linkage between 5-HT6Rs and brain functions remains poorly understood. Here, we examined the effects of 5-HT6R-mediated cell morphological changes using immunocytochemistry, Western blot, and live-cell imaging assays. Our results showed that the activation of 5-HT6Rs caused morphological changes and increased cell surface area in HEK293 cells expressing 5-HT6Rs. Treatment with 5-HT specifically increased RhoA-GTP activity without affecting other Rho family proteins, such as Rac1 and Cdc42. Furthermore, live-cell imaging in hippocampal neurons revealed that activation of 5-HT6Rs using a selective agonist, ST1936, increased the density and size of dendritic protrusions along with the activation of RhoA-GTP activity and that both effects were blocked by pretreatment with a selective 5-HT6R antagonist, SB258585. Taken together, our results show that 5-HT6R plays an important role in the regulation of cell morphology via a RhoA-dependent pathway in mammalian cell lines and primary neurons.

Smek promotes corticogenesis through regulating Mbd3's stability and Mbd3/NuRD complex recruitment to genes associated with neurogenesis

The fate of neural progenitor cells (NPCs) during corticogenesis is determined by a complex interplay of genetic or epigenetic components, but the underlying mechanism is incompletely understood. Here, we demonstrate that Suppressor of Mek null (Smek) interact with methyl-CpG-binding domain 3 (Mbd3) and the complex plays a critical role in self-renewal and neuronal differentiation of NPCs. We found that Smek promotes Mbd3 polyubiquitylation and degradation, blocking recruitment of the repressive Mbd3/nucleosome remodeling and deacetylase (NuRD) complex at the neurogenesis-associated gene loci, and, as a consequence, increasing acetyl histone H3 activity and cortical neurogenesis. Furthermore, overexpression of Mbd3 significantly blocked neuronal differentiation of NPCs, and Mbd3 depletion rescued neurogenesis defects seen in Smek1/2 knockout mice. These results reveal a novel molecular mechanism underlying Smek/Mbd3/NuRD axis-mediated control of NPCs' self-renewal and neuronal differentiation during mammalian corticogenesis.

4-parvifuran inhibits metastatic and invasive actions through the JAK2/STAT3 pathway in osteosarcoma cells

This study was performed to examine the anticancer and anti-metastatic effects of 4-parvifuran (PVN), a novel flavonoid isolated from the heartwood of Dalbergia odorifera, and to study its underlying signaling pathway in human osteosarcoma cells. In the present study, PVN was found to inhibit cell proliferation in a concentration- and time-dependent manner in the human osteosarcoma cell lines studied (MG-63 and U-2 OS) and induce apoptosis, as evidenced by Annexin V⁺ and TUNEL⁺ cells. Cleaved poly (ADP-ribose) polymerase (PARP) and caspase-3 were up-regulated while anti-apoptotic proteins including Bcl-2, Bcl-xL, and survivin were down-regulated after treatment with PVN. Matrigel cell migration assay, invasion assay, and soft agar assay were used to show that PVN effectively suppressed cell migration and invasion and colony formation in osteosarcoma cells. Protein and mRNA levels of MMP-2 and MMP-9 were reduced by PVN in a concentration-dependent manner. Furthermore, PVN inhibited Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3), mitogen-activated protein kinases (MAPKs) including JNK, ERK, p38 kinase, and cAMP response element-binding protein (CREB). Therefore, this is the first study to demonstrate that PVN might be a novel anticancer and anti-metastatic agent for the treatment of osteosarcoma through the inhibition of JAK2/STAT3, MAPKs, and CREB signaling pathways.

A novel organosulfur compound, thiacremonone, regulates RANKL-induced osteoclast differentiation

The medicinal properties of functionally active organosulfur compounds have received great attention for applications in treating various diseases.

4-Methoxydalbergione suppresses growth and induces apoptosis in human osteosarcoma cells in vitro and in vivo xenograft model through down-regulation of the JAK2/STAT3 pathway

Although the heartwood of Dalbergia odorifera T. Chen (Leguminosae) is an important source of traditional Korean and Chinese medicines, the effects of novel compound methoxydalbergione (4-MD) isolated from Dalbergia odorifera was not reported. Herein, we investigated the effects of the 4-MD in vitro and in vivo against osteosarcoma cells and its molecular mechanisms. 4-MD inhibited the proliferation of osteosarcoma cells and induced apoptosis as evidenced by Annexin V + and TUNEL + cells. This apoptosis was accompanied by upregulation of apoptotic proteins (procaspase-3 and PARP), but downregulation of anti-apoptotic proteins (Bcl-2, Bcl-xL, and Survivin). 4-MD inhibited phosphorylation of JAK2 and STAT3 with the inactivation of mitogen-activated protein kinases (MAPKs) and CREB, and the upregulation of PTEN in osteosarcoma cells. Importantly, 4-MD reduced colony formation in soft agar and inhibited tumor growth in mice xenograft model in association with the reduced expression of PCNA, Ki67, p-STAT3, and Survivin. Taken together, the present study for the first time demonstrates that 4-MD exerts in vitro and in vivo anti-proliferative effects against osteosarcoma cells through the inhibition of the JAK2/STAT3 pathway, and suggest the potential for therapeutic application of 4-MD in the treatment of osteosarcoma.

N-methyl-D-aspartate (NMDA) impairs myogenesis in C2C12 cells

INTRODUCTION

N-methyl-d-aspartate (NMDA) is expressed in sensory neurons and plays important roles in peripheral pain mechanisms. The aim of this study was to examine the effects and molecular mechanisms of NMDA on C2C12 myoblast proliferation and differentiation.

METHODS

Cytotoxicity and differentiation were examined by the MTT assay, reverse transcription-polymerase chain reaction, and immunofluorescence.

RESULTS

NMDA had no cytotoxicity (10-500 μM) and inhibited myoblastic differentiation of C2C12 cells, as assessed by F-actin immunofluorescence and levels of mRNAs encoding myogenic markers such as myogenin and myosin heavy-chain 2. It inhibited phosphorylation of mammalian target of rapamycin (mTOR) by inactivating mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38. It induced reactive oxygen species production. Furthermore, NMDA-suppressed expression of F-actin was reversed by adding the antioxidant N-acetylcysteine.

CONCLUSIONS

Collectively, these results indicate that NMDA impairs myogenesis or myogenic differentiation in C2C12 cells through the mTOR/MAPK signaling pathways and may lead to skeletal muscle degeneration. Muscle Nerve 56: 510-518, 2017.

Magnetic nanofiber scaffold-induced stimulation of odontogenesis and pro-angiogenesis of human dental pulp cells through Wnt/MAPK/NF-κB pathways

OBJECTIVE

Magnetic biomaterials have recently gained great attention due to their some intriguing cell and tissue responses. However, little attention has been given to the fields of dental tissue regeneration. In this sense, we aim to investigate the effects of magnetic nanofiber scaffolds on the human dental pulp cell (HDPC) behaviors and to elucidate the underlying signaling mechanisms in the events.

METHODS

Magnetic nanofiber scaffolds incorporating magnetic nanoparticles at varying contents were prepared into nanofibrous matrices to cultivate cells. Cell growth by MTS assay, odontoblastic differentiation by alkaline phosphatase (ALP) activity, mineralization, and the mRNA expression of differentiation-related genes of HDPCs, in vitro angiogenesis by migration and capillary tube formation in endothelial cells on the conditioned medium obtained from HDPSCs in the presence or absence of scaffolds. Western blot analysis and confocal immunofluorescene were used to asses signaling pathways.

RESULTS

The growth of HDPCs was significantly enhanced on the magnetic scaffolds with respect to the non-magnetic counterpart. The odontogenic differentiation of cells was significantly up-regulated by the culture with magnetic scaffolds. Furthermore, the magnetic scaffolds promoted the HDPC-induced angiogenesis of endothelial cells. The expression of signaling molecules, Wnt3a, phosphorylated GSK-3β and nuclear β-catenin, was substantially stimulated by the magnetic scaffolds; in parallel, the MAPK and NF-κB were highly activated when cultured on the magnetic nanofiber scaffolds.

SIGNIFICANCE

This study is the first to demonstrate that magnetic nanofiber scaffolds stimulate HDPCs in the events of growth, odontogenic differentiation, and pro-angiogenesis, and the findings imply the novel scaffolds can be potentially useful as dentin-pulp regenerative matrices.

Serotonin 6 receptor controls Alzheimer's disease and depression

Alzheimer’s disease (AD) and depression in late life are one of the most severe health problems in the world disorders. Serotonin 6 receptor (5-HT₆R) has caused much interest for potential roles in AD and depression. However, a causative role of perturbed 5-HT₆R function between two diseases was poorly defined. In the present study, we found that a 5-HT₆R antagonist, SB271036 rescued memory impairment by attenuating the generation of Aβ via the inhibition of γ-secretase activity and the inactivation of astrocytes and microglia in the AD mouse model. It was found that the reduction of serotonin level was significantly recovered by SB271036, which was mediated by an indirect regulation of serotonergic neurons via GABA. Selective serotonin reuptake inhibitor (SSRI), fluoxetine significantly improved cognitive impairment and behavioral changes. In human brain of depression patients, we then identified the potential genes, amyloid beta (A4) precursor protein-binding, family A, member 2 (APBA2), well known AD modulators by integrating datasets from neuropathology, microarray, and RNA seq. studies with correlation analysis tools. And also, it was demonstrated in mouse models and patients of AD. These data indicate functional network of 5-HT₆R between AD and depression.

PRDX6 controls multiple sclerosis by suppressing inflammation and blood brain barrier disruption

Multiple sclerosis (MS) is a complex disease with an unknown etiology and has no effective medications despite extensive research. Antioxidants suppress oxidative damages which are implicated in the pathogenesis of MS. In this study, we showed that the expression of an antioxidant protein peroxiredoxin 6 (PRDX6) is markedly increased in spinal cord of mice with experimental autoimmune encephalomyelitis (EAE) compared to other PRDXs. PRDX6 transgenic (Tg) mice displayed a significant decrease in clinical severity and attenuated demyelination in EAE compared to wide type mice. The increased PRDX6 expression in astrocytes of EAE mice and MS patients reduced MMP9 expression, fibrinogen leakage, chemokines, and free radical stress, leading to reduction in blood-brain-barrier (BBB) disruption, peripheral immune cell infiltration, and neuroinflammation. Together, these findings suggest that PRDX6 expression may represent a therapeutic way to restrict inflammation in the central nervous system and potentiate oligodendrocyte survival, and suggest a new molecule for neuroprotective therapies in MS.

Delivery of dexamethasone from bioactive nanofiber matrices stimulates odontogenesis of human dental pulp cells through integrin/BMP/mTOR signaling pathways

Therapeutically relevant design of scaffolds is of special importance in the repair and regeneration of tissues including dentin and pulp. Here we exploit nanofiber matrices that incorporate bioactive glass nanoparticles (BGNs) and deliver the odontogenic drug dexamethasone (DEX) to stimulate the odontogenic differentiation of human dental pulp cells (HDPCs). DEX molecules were first loaded onto the BGN, and then the DEX-BGN complex was incorporated within the biopolymer nanofiber matrix through electrospinning. The release of DEX continued over a month, showing a slow releasing profile. HDPCs cultured on the DEX-releasing BGN matrices were viable, proliferating well up to 14 days. The odontogenic differentiation, as assessed by alkaline phosphatase activity, mRNA expression of genes, and mineralization, was significantly stimulated on the matrices incorporating BGN and further on those releasing DEX. The DEX-releasing BGN matrices highly upregulated the expression of the integrin subsets α1, α5, and β3 as well as integrin downstream signaling molecules, including focal adhesion kinase (FAK), Paxillin, and RhoA, and activated bone morphogenetic protein mRNA and phosphorylation of Smad1/5/8. Furthermore, the DEX-releasing BGN-matrices stimulated Akt and mammalian target of rapamycin (mTOR), which was proven by the inhibition study. Collectively, the designed therapeutic nanofiber matrices that incorporate BGN and deliver DEX were demonstrated to promote odontogenesis of HDPCs, and the integrins, bone morphogenetic protein, and mTOR signaling pathways are proposed to be the possible molecular mechanisms. While further in vivo studies are still needed, the DEX-releasing bioactive scaffolds are considered as a potential therapeutic nanomatrix for regenerative endodontics and tissue engineering.

Expression of Caveolin-1 in Periodontal Tissue and Its Role in Osteoblastic and Cementoblastic Differentiation In Vitro

It has been previously reported that caveolin-1 (Cav-1) knockout mice exhibit increased bone size and stiffness. However, the expression and role of Cav-1 on periodontal tissue is poorly understood. The aim of this study was to investigate the immunohistochemical expression of Cav-1 in the mouse periodontium and explore the role of Cav-1 on osteoblastic and cementoblastic differentiation in human periodontal ligament cells (hPDLCs), cementoblasts, and osteoblasts. To reveal the molecular mechanisms of Cav-1 activity, associated signaling pathways were also examined. Immunolocalization of Cav-1 was studied in mice periodontal tissue. Differentiation was evaluated by ALP activity, alizarin red S staining, and RT-PCR for marker genes. Signal transduction was analyzed using Western blotting and confocal microscopy. Cav-1 expression was observed in hPDLCs, cementoblasts, and osteoblasts of the periodontium both in vivo and in vitro. Inhibition of Cav-1 expression by methyl-β-cyclodextrin (MβCD) and knockdown of Cav-1 by siRNA promoted osteoblastic and cementoblastic differentiation by increasing ALP activity, calcium nodule formation, and mRNA expression of differentiation markers in hPDLCs, cementoblasts, and osteoblasts. Osteogenic medium-induced BMP-2 and BMP-7 expression, and phosphorylation of Smad1/5/8 were enhanced by MβCD and siRNA knockdown of Cav-1, which was reversed by BMP inhibitor noggin. MβCD and Cav-1 siRNA knockdown increased OM-induced AMPK, Akt, GSK3β, and CREB phosphorylation, which were reversed by Ara-A, a specific AMPK inhibitor. Moreover, OM-induced activation of p38, ERK, JNK, and NF-κB was enhanced by Cav-1 inhibition. This study demonstrates, for the first time, that Cav-1 is expressed in developing periodontal tissue and in vitro in periodontal-related cells. Cav-1 inhibition positively regulates osteoblastic differentiation in hPDLCs, cementoblasts, and osteoblasts via BMP, AMPK, MAPK, and NF-κB pathway. Thus, Cav-1 inhibition may be a novel molecular target for therapeutic approaches in periodontitis or osteolytic disease.

IL-32α suppresses colorectal cancer development via TNFR1-mediated death signaling

Inflammation is associated with cancer-prone microenvironment, leading to cancer. IL-32 is expressed in chronic inflammation-linked human cancers. To investigate IL-32α in inflammation-linked colorectal carcinogenesis, we generated a strain of mice, expressing IL-32 (IL-32α-Tg). In IL-32α-Tg mice, azoxymethane (AOM)-induced colon cancer incidence was decreased, whereas expression of TNFR1 and TNFR1-medicated apoptosis was increased. Also, IL-32α increased ROS production to induce prolonged JNK activation. In colon cancer patients, IL-32α and TNFR1 were increased. These findings indicate that IL-32α suppressed colon cancer development by promoting the death signaling of TNFR1.

Magnetic Nanocomposite Scaffold-Induced Stimulation of Migration and Odontogenesis of Human Dental Pulp Cells through Integrin Signaling Pathways

Magnetism is an intriguing physical cue that can alter the behaviors of a broad range of cells. Nanocomposite scaffolds that exhibit magnetic properties are thus considered useful 3D matrix for culture of cells and their fate control in repair and regeneration processes. Here we produced magnetic nanocomposite scaffolds made of magnetite nanoparticles (MNPs) and polycaprolactone (PCL), and the effects of the scaffolds on the adhesion, growth, migration and odontogenic differentiation of human dental pulp cells (HDPCs) were investigated. Furthermore, the associated signaling pathways were examined in order to elucidate the molecular mechanisms in the cellular events. The magnetic scaffolds incorporated with MNPs at varying concentrations (up to 10%wt) supported cellular adhesion and multiplication over 2 weeks, showing good viability. The cellular constructs in the nanocomposite scaffolds played significant roles in the stimulation of adhesion, migration and odontogenesis of HDPCs. Cells were shown to adhere to substantially higher number when affected by the magnetic scaffolds. Cell migration tested by in vitro wound closure model was significantly enhanced by the magnetic scaffolds. Furthermore, odontogenic differentiation of HDPCs, as assessed by the alkaline phosphatase activity, mRNA expressions of odontogenic markers (DMP-1, DSPP,osteocalcin, and ostepontin), and alizarin red staining, was significantly stimulated by the magnetic scaffolds. Signal transduction was analyzed by RT-PCR, Western blotting, and confocal microscopy. The magnetic scaffolds upregulated the integrin subunits (α1, α2, β1 and β3) and activated downstream pathways, such as FAK, paxillin, p38, ERK MAPK, and NF-κB. The current study reports for the first time the significant impact of magnetic scaffolds in stimulating HDPC behaviors, including cell migration and odontogenesis, implying the potential usefulness of the magnetic scaffolds for dentin-pulp tissue engineering.

Effects of Palm Kernel Expellers on Productive Performance, Nutrient Digestibility, and White Blood Cells of Lactating Sows

This experiment was conducted to investigate the effects of palm kernel expellers on productive performance, nutrient digestibility, and changes in white blood cells (WBC) of lactating sows. A total of 14 sows (200±12 kg of average body weight [BW]; 2.5 of average parity) were used and moved from gestation room to farrowing room on d 109 of gestation. Sows were randomly assigned to 2 dietary treatments in a completely randomized design. The treatments were a diet based on corn and soybean meal (CON) and CON added with 20% of palm kernel expellers (PKE). Sows were fed the treatments for 28 days (weaning) after farrowing. Blood was collected from each sow and 4 randomly selected piglets from each sow before farrowing or on d 3, 7, or 14 of lactation. Sows were fed respective treatments containing 0.2% chromic oxide from d 15 to 21 of lactation. Fecal samples were collected daily for the last 3 days after the 4-d adjustment period. Measurements were performances and WBC changes of sows and litter, nutrient digestibility of sows, and daily diarrhea of litter. Sows fed PKE had greater average daily feed intake (7.38 vs 7.10 kg/d; p<0.05) and lost less BW (−6.85 vs −8.54 kg; p<0.05) and backfat depth (−0.42 vs −0.71 mm; p<0.05) than those fed CON. However, there were no differences on digestibility of dry matter, nitrogen, and energy and weaning to estrus interval of sows fed either CON or PKE. Piglets from sows fed PKE gained more BW (203 vs 181 g/d; p = 0.08) and had less frequency of diarrhea (6.80 vs 8.56%; p = 0.07) than those from sows fed CON. On the other hand, no difference was found on preweaning mortality of piglets from sows fed either CON or PKE. Sows fed PKE had lower number of WBC (9.57 vs 11.82 ×10³/μL; p = 0.09) before farrowing than those fed CON, but no difference on d 3 and 7. Similarly, piglets from sows fed PKE had also lower number of WBC (7.86 vs 9.80 ×10³/μL; p<0.05) on d 14 of lactation than those from sows fed CON, but no difference on d 3 and 7. In conclusion, addition of 20% palm kernel expellers to lactation diet based on corn and soybean meal had no negative effects on productive performance, nutrient digestibility, and WBC changes of lactating sows.

PRDX6 promotes tumor development via the JAK2/STAT3 pathway in a urethane-induced lung tumor model

Peroxiredoxin 6 (PRDX6) is a bifunctional protein with both glutathione peroxidase (GPx) and iPLA2 activities. Even though several pathophysiological functions have been studied, the definitive role of PRDX6 in tumor growth is not clear. Here, we compared carcinogen-induced tumor growth in PRDX6-transgenic (Tg) mice and non-Tg mice to evaluate the roles of PRDX6 in lung tumor development. Urethane (1g/kg)-induced tumor incidence in PRDX6-Tg mice was significantly higher compared to non-Tg mice. In the tumors of PRDX6-Tg mice, the activation of JAK2/STAT3 and STAT3 DNA binding were also increased, accompanied by increased GPx and iPLA2 activities. PRDX6 was colocalized with JAK2 in tumor tissues and lung cancer cells and also showed physical interaction with JAK2. We found that increasing levels of PRDX6 increase the activation of the JAK2/STAT3 pathway. Furthermore, PRDX6-Tg mice showed altered cytokine levels in the tumors, especially leading to increased CCL5 levels. We validated that the activation of JAK2 was also decreased in lung tumors of CCR5(-/-) mice, and CCL5 increased the JAK2/STAT3 pathway in the lung cancer cells. Thus, our findings suggest that PRDX6 promotes lung tumor development via its mediated and CCL5-associated activation of the JAK2/STAT3 pathway.

Interleukin-32β ameliorates metabolic disorder and liver damage in mice fed high-fat diet

OBJECTIVE

Chronic excessive food intake leads to energy imbalance, resulting in hepatic steatosis and inflammation. Interleukin-32 (IL-32) is known to be a pro-inflammatory cytokine associated with chronic inflammation and cancer. Therefore, the relationship between IL-32 and chronic excessive food intake-induced liver disease was investigated.

METHODS

Male IL-32β transgenic and wild-type mice were fed a high-fat diet (HFD) for 15 weeks. They were compared with wild-type mice on a standard chow diet. Daily food intake, body and liver weight, serum biochemistry, histopathological analysis of the liver, and hepatic immune response were determined.

RESULTS

IL-32β mice on HFD showed lower lipid accumulation, reduced infiltration of immune cells, and lower production of pro-inflammatory cytokines in the liver. The expression of the peroxisome proliferator-activated receptor γ (PPARγ) was downregulated and the adenosine 50-monophosphate (AMP)-activated protein kinase (AMPK) was activated in the liver of IL-32β mice compared to wild-type mice. Furthermore, IL-32β over-expression activated the AMPK pathway and IL-32β downregulation inactivated the AMPK pathway in HepG2 cells under high-glucose conditions.

CONCLUSIONS

These data suggest that IL-32β modulates lipid accumulation through inhibition of PPARγ expression and AMPK activation.

Nanotopological-tailored calcium phosphate cements for the odontogenic stimulation of human dental pulp stem cells through integrin signaling

Nanotopological-tailored calcium phosphate cements stimulate odontogenesis of human dental pulp cells through integrin-mediated signaling pathways.