Linarin promotes osteogenic differentiation by activating the BMP-2/RUNX2 pathway via protein kinase A signaling

Association between dietary selenium intake and the prevalence of osteoporosis and its role in the treatment of glucocorticoid-induced osteoporosis

BACKGROUND

Long-term glucocorticoid therapy may lead to osteoporosis (OP). Selenium (Se) is an essential microelement for human health and bone health. This study evaluated the association between dietary Se intake and the prevalence of OP and further explored the potential therapeutic effect of Se on glucocorticoid-induced OP (GIOP) in vivo and in vitro.

METHODS

Data were collected from a population-based cross-sectional study conducted in our hospital. OP is diagnosed based on bone mineral density (BMD) measurements using compact radiographic absorptiometry. Dietary Se intake was assessed using a semi-quantitative food frequency questionnaire. The association between dietary Se intake and OP prevalence was analyzed by multivariable logistic regression. In animal experiments, male Sprague-Dawley rats were intramuscularly injected with dexamethasone (1 mg/kg) daily to induce GIOP, while different doses of Se were supplemented in rat drinking water for 60 d. BMD and biomechanical parameters of rat femur were measured. The histopathological changes of the femur were observed by HE staining, the number of osteoclasts was observed by TRAP staining, and OCN positive expression was detected by immunohistochemical staining. OPG, RANKL, Runx2, and BMP2 in rat femur were detected by Western blot. Bone turnover markers and oxidative stress markers were measured using commercial kits. MC3T3-E1 cells were induced to osteogenic differentiation, stimulated with DXM (100 μM), and/or treated with Se at different doses. Cell proliferation and apoptosis were assessed by CCK-8 and flow cytometry. ALP activity was detected by ALP staining and cell mineralization was observed by alizarin red staining.

RESULTS

Participants with lower dietary Se intake had higher OP prevalence. Se supplementation improved BMD, biomechanical parameters, and histopathological changes of the femur in GIOP rats. Se supplementation also suppressed DXM-induced changes in bone turnover- and oxidative stress-related markers. Under DXM conditions, Se treatment induced MC3T3-E1 cell proliferation, ALP activity, and mineralization.

CONCLUSION

Lower Dietary Se intake is associated with OP prevalence. Moreover, Se takes a position in bone protection and anti-oxidative stress in GIOP models. Therefore, Se may be a complementary potential treatment for GIOP.

Anti-inflammatory and antioxidant traditional Chinese Medicine in treatment and prevention of osteoporosis

A metabolic bone disorder called osteoporosis is characterized by decreased bone mass and compromised microarchitecture. This condition can deteriorate bones and raise the risk of fractures. The two main causes of osteoporosis are an increase in osteoclast activity or quantity and a decrease in osteoblast viability. Numerous mechanisms, including estrogen shortage, aging, chemical agents, and decreased mechanical loads, have been linked to osteoporosis. Inflammation and oxidative stress have recently been linked to osteoporosis, according to an increasing number of studies. The two primary medications used to treat osteoporosis at the moment are bisphosphonates and selective estrogen receptor modulators (SERMs). These medications work well for osteoporosis brought on by aging and estrogen deprivation, however, they do not target inflammation and oxidative stress-induced osteoporosis. In addition, these drugs have some limitations that are attributed to various side effects that have not been overcome. Traditional Chinese medicine (TCM) has been applied in osteoporosis for many years and has a high safety profile. Therefore, in this review, literature related to botanical drugs that have an effect on inflammation and oxidative stress-induced osteoporosis was searched for. Moreover, the pharmacologically active ingredients of these herbs and the pathways were discussed and may contribute to the discovery of more safe and effective drugs for the treatment of osteoporosis.

Exosomes from Adipose-Derived Stem Cells Alleviate Dexamethasone-Induced Bone Loss by Regulating the Nrf2/HO-1 Axis

The widespread use of therapeutic glucocorticoids has increased the incidences of glucocorticoid-induced osteoporosis (GIOP). Oxidative stress and mitochondrial dysfunction are major causes of GIOP; therefore, alleviation of excess oxidative stress in osteoblasts is a potential therapeutic strategy for osteoporosis. Exosomes derived from ADSCs (ADSCs-Exos), as novel cell-free therapeutics, can modulate various biological processes, such as immunomodulation, reduce oxidative damage, and promote tissue repair as well as regeneration. In this study, ADSCs-Exos restored the viability and osteogenic potential of MC3T3-E1 cells by attenuating apoptosis, oxidative damage, intracellular ROS generation, and mitochondrial dysfunction. Moreover, after pretreatment with ADSCs-Exos, Nrf2 expressions were upregulated in Dex-stimulated osteoblasts. Inhibitory assays showed that silencing Nrf2 partially eliminated the protective effects of ADSCs-Exos. The rat model assays confirmed that ADSCs-Exos alleviated the Dex-induced increase in oxidation levels, restored bone mass of the distal femur, and increased the expressions of Nrf2 and osteogenic markers in bone tissues. Thus, ADSCs-Exos alleviated apoptosis and oxidative stress by regulating Nrf2/HO-1 expressions after Dex and prevented the development of GIOP in vivo.

Evaluating the Potential Anticancer Properties of Salvia triloba in Human-Osteosarcoma U2OS Cell Line and Ovarian Adenocarcinoma SKOV3 Cell Line

Salvia triloba (S. triloba) is an herb inherently linked to traditional medicine systems in the Eastern Mediterranean region. There is minimal experimental evidence however, regarding the anticancer effects of S. triloba in both osteosarcoma and ovarian cancer. In this study, we investigated the effects of crude (macerated) S. triloba ethanol and acetone leaf extracts on viability, migratory ability, and the expression of genes regulating these activities in U2OS and SKOV3 cells using MTT assay, scratch-wound healing/trans-well migration assay, and RT-qPCR respectively. MTT assay results indicated that the acetone extract significantly reduced both U2OS and SKOV3 cell viability with half-maximal inhibitory concentrations (IC50) of 54.51 ± 1.10 µg/mL and 75.96 ± 1.0237 µg/mL respectively; these concentrations further displayed negligible hemolytic activity. The combination of acetone extract (19 µg/mL) and paclitaxel (0.787 µg/mL) displayed synergy and reduced SKOV3 cell viability by over 90%. Additionally, the trans-well migration assay illustrated that the acetone extract (IC50) inhibited both U2OS and SKOV3 cell migration by more than 50%. Moreover, S. triloba acetone extract significantly downregulated the steady-state mRNA expression of key genes involved in driving select cancer hallmarks. Four fractions were generated from the acetone extract by thin layer chromatography (TLC), and the obtained retention factors (Rf) (ranging from 0.2 to 0.8) suggested a mixture of high and moderately polar compounds whose bioactivities require further investigation. In addition, FTIR measurements of the extract revealed peaks corresponding to OH, aliphatic CH, and ester groups suggesting the presence of phenolic compounds, terpenes, and polysaccharides. Altogether, these results suggest that S. triloba possesses potential therapeutic compounds that inhibit cell proliferation and migration, and modulate several genes involved in osteosarcoma and ovarian carcinoma progression.

A new hydrogel with fluorapatite nanoparticles for osteogenic differentiation of human adipose-derived stem cells in tissue engineering field

Since scaffolds are engineered to support functional tissue formation, their design and materials play an essential role in medical fields by providing different mechanical function. The aim of this study was to investigate the synthesis and structural characterization of collagen-gelatin (COL-GEL) composite scaffolds containing fluorapatite (FA) nanoparticles as well as evaluation of the osteogenic differentiation of human adipose-derived stem cells (hADSCs). First, the composite scaffolds were evaluated using Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The cytotoxicity of scaffolds and various concentrations of FA nanoparticles was studied through MTT assay and acridine orange/ethidium bromide staining. Next, the differentiated hADSCs were analyzed using Alizarin red and von Kossa staining, calcium content assay, alkaline phosphatase (ALP) activity, real-time RT-PCR, and immunocytochemical analyses. According to the characterization analyses, the composite scaffolds were properly integrated. The results also illustrated that COL-GEL composite scaffolds in the presence of FA nanoparticles not only showed no cytotoxicity but also increased ALP activity and calcium deposition as well as the expression of osteogenic genes, including Runx2, Col-I, ALP, and osteocalcin and the synthesis of proteins such as osteocalcin and osteopontin in vitro. The obtained data were confirmed by Alizarin red and von Kossa staining. These results are very promising for further tissue engineering experiments, in which FA nanoparticle incorporation into COL-GEL composite scaffolds is a novel approach that improves the surface COL-GEL composite scaffolds for tissue engineering application in vitro.

Linarin Protects against Cadmium-Induced Osteoporosis Via Reducing Oxidative Stress and Inflammation and Altering RANK/RANKL/OPG Pathway

Cadmium (Cd) contamination in the environment is a major public health concern since it has been linked to osteoporosis and other bone deformities. Linarin is a flavonoid glycoside, and it can promote osteoblastogenesis. This research aimed to investigate the potential role of linarin against Cd-exposed bone deformations in mice model. In our research, male mice were randomly allocated into four groups: control, Cd-exposed, and Cd + linarin (20 and 40mg/kg/bw, respectively). Linarin prevented body weight loss, increased serum calcium (Ca) and phosphorus (P), and bone alkaline phosphatase (BAP) levels in Cd-exposed groups. Furthermore, linarin treatment at 20 and 40mg/kg/bw significantly decreased RANK and OPG, resulting in an increase in RANKL mRNA levels and protein distribution in the bone of Cd-exposed mice. In addition, the bone of Cd-exposed mice administered with linarin showed higher TRAP, NFATc1, MMP9, and RUNX2 mRNA levels and protein distribution. Linarin significantly decreased oxidative stress in Cd-exposed mice bone by decreasing MDA, a lipid peroxidation product. Moreover, linarin protects Cd-exposed mice antioxidant enzymes by increasing bone SOD, CAT, and GPx levels. Besides, linarin suppresses alterations in the inflammatory system, i.e., NF-κB p65/IKKβ, by reducing NF-κB p65, IKKβ, IL-6, and TNF-α in the bone of Cd-exposed animals. This study concluded that linarin has potential to cure osteoporosis in Cd-exposed mice by reducing oxidative stress and inflammation and modulating the RANK/RANKL/OPG pathway.

An In Vitro Evaluation of Selenium Nanoparticles on Osteoblastic Differentiation and Antimicrobial Properties against Porphyromonas gingivalis

Despite numerous treatment methods, there is no gold standard for the treatment of peri-implantitis—an infectious peri-implant disease. Here, we examined selenium nanoparticles (SeNPs) at a wide range of concentrations to investigate their cytotoxicity, regulation of osteoblastic differentiation, and assessed the antibacterial effect against Porphyromonas gingivalis. SeNPs (mean size: 70 nm; shape: near-spherical; concentration: 0–2048 ppm) were tested against the MC3T3-E1 osteoblast precursor cell line and P. gingivalis red complex pathogen. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) analysis was used to evaluate the bone morphogenetic protein 2 (BMP-2) signaling pathway. SeNPs at concentrations of 2–16 ppm showed no obvious cytotoxicity and promoted good mineralization and calcification. SeNPs at concentrations 64 ppm and below influenced gene expression promoting osteoblastic differentiation, whereas at high concentrations inhibited the expression of Runt-related transcription factor 2 (Runx2). The growth of P. gingivalis was significantly inhibited at SeNP concentrations of more than 4 ppm. SeNPs at low concentrations promoted osteoblastic differentiation while strongly inhibiting peri-implantitis pathogen growth. This study represents one of the few in vitro assessments of SeNPs against a red complex pathogen and the regulatory effect on osteoblastic differentiation. The findings demonstrate SeNPs could potentially be used for future application on implant coating.

In-vitro viability of bone scaffolds fabricated using the adaptive foam reticulation technique

The adaptive foam reticulation technique combines the foam reticulation and freeze casting methodologies of fabricating bone reparative scaffolds to offer a potential alternative to autografts. For the first time this paper studies the effect of processing on the mechanical properties and in-vitro cell growth of controllably generating a hierarchical structure of macro- (94 ± 6 to 514 ± 36 μm) and microporosity (2-30 μm) by the inclusion of camphene as a porogen during processing. Scaffolds were produced with porogen additions of 0-25 wt%. Porosity values of the structures of 85-96% were determined using the Archimedes technique and verified using X-ray Computed Tomography. The strength of the hydroxyapatite scaffolds, 5.70 ± 1.0 to 159 ± 61 kPa, correlated to theoretically determined values, 3.71 ± 0.8 to 134 ± 12 kPa, calculated by the novel incorporation of a shape factor into a standard equation. Fibroblast (3T3) and pre-osteoblast (MC3T3) cell growth was found to be significantly (P < 0.005) improved using 25 wt% porogen. This was supported by increased levels of alkaline phosphatase and was thought to result from greater dissolution as quantified by increased calcium levels in incubating media. The combination of these properties renders adaptive foam reticulation-fabricated scaffolds suitable for non-structural bone regenerative applications in non-load bearing bone defects.

Antiosteoporosis Studies of 20 Medicine Food Homology Plants Containing Quercetin, Rutin, and Kaempferol: TCM Characteristics, In Vivo and In Vitro Activities, Potential Mechanisms, and Food Functions

Dietary nutraceutical compounds have been evidenced as backbone for bone health in recent years. It is reported that medicine food homology (MFH) plants have multiple nutraceutical compounds. Based on our literature research, 20 MFH plants caught our attention because they contain three popular antiosteoporosis compounds simultaneously: quercetin, rutin, and kaempferol. According to traditional Chinese medicine (TCM), their characteristics including natures, flavors, attributive to meridian tropism, and efficacies were listed. The relationships between TCM efficacies, such as “heat clearing,” “tonic,” and “the interior warming,” and antiosteoporosis pharmacological actions such as antioxidant and immune regulation were discussed. The in vivo antiosteoporosis effects of the 20 MFH plants were summarized. The in vitro antiosteoporosis activities and related mechanisms of the 20 plants and quercetin, rutin, kaempferol were detailed. The TGF-β-Smad signaling, fibroblast growth factor, and Wnt/β-catenin signaling on bone formation and the RANKL signaling, NF-κB signaling, and macrophage-colony-stimulating factor on bone resorption were identified. From food point, these 20 MFH plants could be classified as condiment, vegetable, fruit, tea and related products, beverage, etc. Based on the above discussion, these 20 MFH plants could be used as daily food supplements for the prevention and treatment against osteoporosis.

TLR4 activation inhibits the proliferation and osteogenic differentiation of skeletal muscle stem cells by downregulating LGI1

Skeletal muscle stem cells (SMSCs) are vital to the growth, maintenance, and repair of the muscles; emerging evidence has indicated that Toll-like receptor 4 (TLR4) can potentially regulate muscle regeneration. In present study, in vitro and in vivo experiments were performed to explore the correlation of TLR4 with leucine-rich glioma-inactivated 1 (LGI1) as well as their effects on the proliferation and osteogenesis potential of SMSCs. In order to examine the regulatory mechanisms of TLR4 and LGI1 in SMSCs, the obtained cells were treated with lipopolysaccharide (LPS, used as an activator of TLR4) of different concentration at different time points as well as the siRNA against LGI1. Subsequently, a series of detection was undertaken in order to measure the proliferation and differentiation potential of SMSCs, which involved detection of the related factors, cell activity, and the sphere-forming capability. Following LPS treatment, the increased TLR4 expression and reduced LGI1 expression were observed. Consequently, we also discovered that Erk signaling pathway was inactivated and cell proliferation and osteogenesis capabilities declined, presented by the downregulation of related factors such as cyclin B1 and runt-related transcription factor 2. Moreover, the cell activity and sphere-formation performance of SMSCs were also declined. These results were also validated in rats with cecal ligation and perforation-induced rat models with sepsis. In conclusion, the present study reveals a regulatory mechanism in SMSCs whereby LGI1 expression is reduced by TLR4, thus impeding cell proliferation and osteogenesis, highlighting TLR4 as a potential therapeutic target against many diseases related to SMSCs.

A Non-thermal Biocompatible Plasma-Modified Chitosan Scaffold Enhances Osteogenic Differentiation in Bone Marrow Stem Cells

Non-thermal biocompatible plasma (NBP) was considered as an efficient tool in tissue engineering to modify the surface of biomaterials. Three-dimensional chitosan scaffolds have been extensively used in different ways because it holds some remarkable properties, including biodegradability and biocompatibility. In this study, we evaluated the osteogenic potential of NBP-treated chitosan scaffolds using two different plasma sources: a dielectric barrier discharge (NBP-DBD) and a soft jet (NBP-J). The surface modification of the scaffold was evaluated using scanning electron microscopy. For osteogenic differentiation of cells, proliferation and differentiation were tested by using bone marrow-derived stem cells (BMSCs). We observed that cell viability using NBP-DBD and NBP-J treated chitosan scaffolds yielded significant improvements in cell viability and differentiation. The results obtained with MTT and live/dead assays showed that NBP-modified scaffold increases cell metabolic by MTT assay and live/dead assay. It also observed that the NBP treatment is more effective at 5 min with DBD and was selected for further investigations. Enhanced osteogenic differentiation was observed using NBP-treated scaffolds, as reflected by increased alkaline phosphatase activity. Our findings showed that NBP is an innovative and beneficial tool for modifying chitosan scaffolds to increase their activity, making them suitable as biocompatible materials and for bone tissue engineering.

Antiosteoporosis effects of a marine antimicrobial peptide pardaxin via regulation of the osteogenesis pathway

Antimicrobial peptides (AMPs) are known to play an important role in natural immunity. Moreover, the diverse biological activities of AMPs showed great potency in treating many diseases. Thus, in this study, we used an AMP, that is, pardaxin, from a marine fish (Pardachirus marmoratus), which has been reported to possess antibacterial and antitumor activities. We first investigated the mechanisms of pardaxin in promoting osteogenic differentiation in vitro and in vivo. As per our data, it was determined that pardaxin could stimulate bone morphogenetic protein-2 (BMP-2) and downstream cascade. The activation of BMP-2 could further induce the phosphorylation of Akt and extracellular signal-regulated kinase (ERK). Additionally, the activation of p-Akt and p-ERK could prompt the elevation and translocation of runt-related transcription factor 2 (runx-2), which is associated with osteoblast differentiation. The translocation of runx-2 initiated transcription and translation of osteogenesis-related markers, including alkaline phosphatase (ALP), osterix, and osteocalcin. Pardaxin significantly facilitated preosteoblast cells in mineralization and reversed dexamethasone- (DM-) induced zebrafish bone formation deficiency by activating the osteogenesis pathway. Therefore, we suggest that pardaxin could be a possible candidate for osteoporosis treatment and a promising therapeutic agent.

Effects of icariin on the fracture healing in young and old rats and its mechanism

CONTEXT

Icariin has attracted increasing attention because of its wide variety of pharmacological effects.

OBJECTIVE

This study investigates whether icariin could promote fracture healing in young and old rats and its mechanisms.

MATERIALS AND METHODS

A Wistar rat model for the tibia fracture in relatively young and old rats, respectively, was established. The rats were divided into four groups: model group, L-icariin (50 mg/kg icariin), M-icariin (100 mg/kg icariin) and H-icariin (200 mg/kg icariin), and intragastric administration of icariin was performed for 10 days or 20 days. In addition, isolated and cultured rat bone mesenchymal stem cells (rBMSCs) from young and old rats were cultured with 5% and 20% of icariin-containing serum, respectively, then cell viability and alkaline phosphatase (ALP) activity were measured.

RESULTS

Icariin administration induced the expression of Runx2, Osterix, BMP-2, p-Smad5 and osteocalcin secretion (young rats: model: 2.50 ± 0.71; L-icariin: 10.10 ± 1.55; M-icariin: 24.95 ± 2.19; H-icariin: 36.80 ± 2.26; old rats: model: 1.55 ± 0.49; L-icariin:6.55 ± 0.50; M-icariin: 15.00 ± 0.85; H-icariin:20.50 ± 2.27) at the fracture site, and increased the levels of bone formation markers (OC, BAP, NTX-1 and CTX-1) in a dose-dependent manner. In vitro, icariin treatment promoted rBMSC viability, increased ALP activity and the expression of BMP-2/Smad5/Runx2 pathway proteins.

DISCUSSION AND CONCLUSIONS

Icariin may accelerate fracture healing by activating the BMP-2/Smad5/Runx2 pathway in relatively young and old rats. The research on the mechanism of icariin to promote fracture healing can provide a theoretical basis for the clinical application and promotion of icariin.

Promotion of osteogenesis by Sweroside via BMP2-involved signaling in postmenopausal osteoporosis

Phlomis umbrosa has been traditionally used for bone diseases in traditional Korean Medicine. Sweroside (SOS), marker compounds of P. umbrosa, has been known to promote osteoblast differentiation. In this study, ameliorative effects of SOS on osteoporosis and potential target pathway were investigated. Ovariectomized mice were administered three doses of SOS three times a week for 4 weeks after inducing osteoporosis. Bone mineral content (BMC) and bone mineral density (BMD) were analyzed by dual energy X-ray absorptiometry. A human osteosarcoma cell line (SaOS-2) was differentiated to clarify the promoting effects of SOS on osteoblast differentiation and bone formation. Osteoblastic bone-forming markers were evaluated in lumbar vertebrae (LV) and mineralized SaOS-2 cells. SOS markedly elevated BMC and BMD levels and attenuated the bone marrow adipocytes in the femoral shaft. SOS increased the formation of bone matrix in SaOS-2 cells. Bone morphogenetic protein-2 (BMP2) and runt-related transcription factor 2 (CBFA1) in LV and SaOS-2 cells were up-regulated by SOS. SOS increased alkaline phosphatase (ALPL), osteopontin (SPP1), and bone sialoprotein-1 (BSPH1). In conclusion, SOS induced the formation of mineralized bone matrix by regulating BMP2/CBFA1-mediated molecules. Therefore, SOS could be a therapeutic compound of treatment for osteoporosis by producing the new bone matrix.

Linarin, a Glycosylated Flavonoid, with Potential Therapeutic Attributes: A Comprehensive Review

Many flavonoids, as eminent phenolic compounds, have been commercialized and consumed as dietary supplements due to their incredible human health benefits. In the present study, a bioactive flavone glycoside linarin (LN) was designated to comprehensively overview its phytochemical and biological properties. LN has been characterized abundantly in the Cirsium, Micromeria, and Buddleja species belonging to Asteraceae, Lamiaceae, and Scrophulariaceae families, respectively. Biological assessments exhibited promising activities of LN, particularly, the remedial effects on central nervous system (CNS) disorders, whereas the remarkable sleep enhancing and sedative effects as well as AChE (acetylcholinesterase) inhibitory activity were highlighted. Of note, LN has indicated promising anti osteoblast proliferation and differentiation, thus a bone formation effect. Further biological and pharmacological assessments of LN and its optimized semi-synthetic derivatives, specifically its therapeutic characteristics on osteoarthritis and osteoporosis, might lead to uncovering potential drug candidates.

Effect of 1,25-Dihydroxyvitamin D3 on Stem Cells from Human Apical Papilla: Adhesion, Spreading, Proliferation, and Osteogenic Differentiation

Currently, it still remains a difficult problem to treat apical insufficiency of young permanent teeth resulted from pulp necrosis or periapical periodontitis. Previous studies have demonstrated that the treatment of revascularization using stem cells from apical papilla (SCAPs) results in increased root length and thickness of traumatized immature teeth and necrotic pulp. In this study, we investigated the role of 1,25-dihydroxyvitamin D3 in regulating the adhesion, spreading, proliferation, and osteogenic differentiation of SCAP, laying the foundation for subsequent clinical drug development. The immature tooth samples were collected in clinical treatment. SCAPs with stable passage ability were isolated and cultured. The multidifferentiation potential was determined by directed induction culture, while the stem cell characteristics were identified by flow cytometry. There were three groups: group A—SCAPs general culture group; group B—SCAPs osteogenesis induction culture group; and group C—SCAPs osteogenesis induction culture+1,25-dihydroxyvitamin D₃ group, and the groups were compared statistically. The proliferation of SCAPs in each groups was detected through CCK-8 assay. RT-qPCR was used to detect the transcription levels of Runx2, ALP, Col I, and OCN of SCAPs in each groups. Results exhibited that the isolated SCAPs had multidifferentiation potential and stem cell characteristics. After 24 h culturing, cells in group C spread better than those in groups A and B. The proliferation activity of SCAPs factored by CCK-8 ranked as group C > group B > group A, while the transcription levels of Runx2, ALP, Col I, and OCN leveled as group C > group B > group A. These results suggested that 1,25-dihydroxyvitamin D₃ can significantly promote the adhesion, spreading, and proliferation of SACPs and improve the osteogenic differentiation of SCAPs by means of regulating upward the transcription level of osteogenic differentiation marker.

Marantodes pumilum Var Alata (Kacip Fatimah) ameliorates derangement in RANK/RANKL/OPG pathway and reduces inflammation and oxidative stress in the bone of estrogen-deficient female rats with type-2 diabetes

BACKGROUND

M. pumilum has been claimed to protect the bone against the adverse effect of estrogen deficiency. Additionally, it also exhibits anti-diabetic activity. In view of these, this study aims to identify the mechanisms underlying the bone protective effect of M. pumilum in the presence of both estrogen deficiency and diabetes mellitus (DM).

METHODS

Ovariectomized, diabetic female rats were given M. pumilum leave aqueous extract (MPLA) (50 and 100 mg/kg/day), estrogen, glibenclamide and estrogen plus glibenclamide for 28 consecutive days. At the end of the treatment, fasting blood glucose (FBG), serum insulin, Ca²⁺, PO₄^3- and bone alkaline phosphatase (BALP) levels were measured. Rats were sacrificed and femur bones were harvested for determination of expression level and distribution of RANK, RANKL, OPG and oxidative stress and inflammatory proteins by molecular biological techniques.

RESULTS

100 mg/kg/day MPLA treatment decreased the FBG and BALP levels but increased the serum insulin, Ca²⁺ and PO₄^3- levels in estrogen deficient, diabetic rats. Expression and distribution of RANKL, NF-κB p65, IKKβ, IL-6, IL-1β and Keap-1 decreased however expression and distribution of RANK, OPG, BMP-2, Type-1 collagen, Runx2, TRAF6, Nrf2, NQO-1, HO-1, SOD and CAT increased in the bone of estrogen deficient, diabetic rats which received 100 mg/kg/day MPLA with greater effects than estrogen-only, glibenclamide-only and estrogen plus glibenclamide treatments.

CONCLUSION

MPLA helps to overcome the adverse effect of estrogen deficiency and DM on the bone and thus this herb could potentially be used for the treatment and prevention of osteoporosis in postmenopausal women with diabetes.

Nobiletin promotes osteogenic differentiation of human osteoblastic cell line (MG-63) through activating the BMP-2/RUNX-2 signaling pathway

Nobiletin (NOB) is polymethoxy flavonoids, which plentifully there in Citrus depressa and they demonstrate numerous pharmacological effects. NOB has an anti-proliferative effect, attenuates ovalbumin-treated eosinophilic airway inflammation and Type II collagen treated arthritis. NOB noticeably inhibits bone resorption and renovates bone loss in mice model, but role of NOB in bone metabolism is unclear. Human bone is a important organ that sustains its homeostasis among bone resorpting osteoclasts and bone developing osteoblasts. The balances of among these two kind of cell outcomes are implicated in bone remodeling. The current study designed to explore possessions of NOB on differentiation and proliferation of MG-63 cells and contribution of morphogenetic protein signaling. Cell proliferation was analyzed by MTT, mineralization analysis by alizarin red staining and morphogenetic signaling protein by RT-PCR. No stimulus outcome of NOB on cell proliferation was found at days of 1, 3 and 7. Accumulation of calcium was augmented after that treatment of NOB. The mRNA expression of BMP-2, COL-I, ALP, OCN, RUNX2 and COL1A1 augmented markedly with NOB supplement. Hence, NOB can stimulate osteogenic differentiation of MG-63, almost certainly by promoting RUNX2 and BMP-2 signaling and this result might provide to its action on stimulation of osteoblast development, differentiation and augments of bone mass.

Water Extract of Mentha arvensis L. Attenuates Estrogen Deficiency-Induced Bone Loss by Inhibiting Osteoclast Differentiation

Mentha arvensis L., is an aromatic herb that belongs to the Lamiaceae family and is widely used in medicinal applications, essential oil applications, and food flavoring. The extract of M. arvensis has been reported to exert sedative-hypnotic, anti-inflammatory, anti-fungal, and anti-bacterial effects. However, its effects on bone metabolism have not yet been studied. Here, we investigated the effects of the water extract of M. arvensis (WEMA) on osteoclast formation in vitro and bone loss in an ovariectomized mouse model. We found that WEMA inhibited osteoclast differentiation by directly acting on osteoclast precursor cells. WEMA inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced the expression of cellular oncogene fos (c-Fos) and nuclear factor of activated T cells c1 (NFATc1), crucial transcription factors for osteoclast differentiation, by suppressing RANKL-induced activation of early signaling pathways such as those of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB). In addition, oral administration of WEMA suppressed ovariectomy-induced trabecular bone loss in mice. We additionally identified phytochemicals in WEMA that are known to have anti-osteoclastogenic or anti-osteoporotic properties. Collectively, these results suggest that WEMA is a promising herbal candidate that can be used to prevent or treat postmenopausal osteoporosis.

The Marine-Derived Natural Product Epiloliolide Isolated from Sargassum horneri Regulates NLRP3 via PKA/CREB, Promoting Proliferation and Anti-Inflammatory Effects of Human Periodontal Ligament Cells

Currently, periodontitis treatment relies on surgical operations, anti-inflammatory agents, or antibiotics. However, these treatments cause pain and side effects, resulting in a poor prognosis. Therefore, in this study, we evaluated the impact of the compound epiloliolide isolated from Sargassum horneri on the recovery of inflammatory inhibitors and loss of periodontal ligaments, which are essential treatment strategies for periodontitis. Here, human periodontal ligament cells stimulated with PG-LPS were treated with the compound epiloliolide, isolated from S. horneri. In the results of this study, epiloliolide proved the anti-inflammatory effect, cell proliferation capacity, and differentiation potential of periodontal ligament cells into osteoblasts, through the regulation of the PKA/CREB signaling pathway. Epiloliolide effectively increased the proliferation and migration of human periodontal ligament cells without cytotoxicity and suppressed the protein expression of proinflammatory mediators and cytokines, such as iNOS, COX-2, TNF-α, IL-6, and IL-1β, by downregulating NLRP3 activated by PG-LPS. Epiloliolide also upregulated the phosphorylation of PKA/CREB proteins, which play an important role in cell growth and proliferation. It was confirmed that the anti-inflammatory effect in PG-LPS-stimulated large cells was due to the regulation of PKA/CREB signaling. We suggest that epiloliolide could serve as a potential novel therapeutic agent for periodontitis by inhibiting inflammation and restoring the loss of periodontal tissue.

Overexpression of miR125b Promotes Osteoporosis Through miR-125b-TRAF6 Pathway in Postmenopausal Ovariectomized Rats

BACKGROUND

Postmenopausal osteoporosis is one of the most common types of osteoporosis that women suffer from. Studies involving molecular mechanisms for designing better therapeutic strategies for postmenopausal osteoporosis are still rare. The present study investigates the role of miR-125b in postmenopausal osteoporosis.

METHODS

Microarray analysis was done to screen the gene database. Tissue samples of postmenopausal women were collected to study the miRNA profiles. MC3T3-E1 cells were used and were submitted for transfection. CCK-8 assay was done to check the viability of cells, whereas toxicity was done by lactate dehydrogenase assay kit. TargetScan was done to target genes of miR-125b followed by confirmation by Luciferase reporter assay. For animal studies a rat model of ovariectomized rats was created. Bone mineral density and biomechanics were measured by densitometer. The mRNA levels were assessed by qRT-PCR and proteins by Western blot assay.

RESULTS

miR-125b was over-expressed in human osteoporosis samples. In vitro studies suggested that miR-125b suppressed the cell viability and promoted release of LDH, it also enhanced the RANKL/OPG ratio and suppressed levels of BMP2 and Runx2. Bioinformatics identified TRAF6 as a potential target of miR-125b, further confirmed by luciferase assay, also miR-125b negatively regulated the levels of TRAF6 gene in osteoporosis bones involving the JAK2/STAT3 cascade. In the rat model, miR-125b decreased the bone mineral density and biomechanical parameters in bones by altering the TRAF6 gene involving the JAK2/STAT3 pathway.

CONCLUSION

The outcomes suggested that miR-125b was responsible for the development of postmenopausal osteoporosis and promoted its progression by the TRAF6 gene via the JAK2/STAT3 pathway.

Linarin and its aglycone acacetin abrogate actin ring formation and focal contact to bone matrix of bone-resorbing osteoclasts through inhibition of αvβ3 integrin and core-linked CD44

BACKGROUND

Since enhanced bone resorption due to osteoclast differentiation and activation cause skeletal diseases, there is a growing need in therapeutics for combating bone-resorbing osteoclasts. Botanical antioxidants are being increasingly investigated for their health-promoting effects on bone. Edible Cirsium setidens contains various polyphenols of linarin, pectolinarin, and apigenin with antioxidant and hepatoprotective effects.

PURPOSE

This study aimed to determine whether linarin present in Cirsium setidens water extracts (CSE) and its aglycone acacetin inhibited osteoclastogenesis of RANKL-exposed RAW 264.7 murine macrophages for 5 days.

METHODS

This study assessed the osteoprotective effects of CSE, linarin and acacetin on RANKL-induced differentiation and activation of osteoclasts by using MTT assay, TRAP staining, Western blot analysis, bone resorption assay actin ring staining, adhesion assay and immunocytochemical assay. This study explored the underlying mechanisms of their osteoprotection, and identified major components present in CSE by HPLC analysis.

RESULTS

Linarin and pectolinarin were identified as major components of CSE. Nontoxic linarin and acacetin as well as CSE, but not pectolinarin attenuated the RANKL-induced macrophage differentiation into multinucleated osteoclasts, and curtailed osteoclastic bone resorption through reducing lacunar acidification and bone matrix degradation in the osteoclast-bone interface. Linarin and acacetin in CSE reduced the transmigration and focal contact of osteoclasts to bone matrix-mimicking RGD peptide. Such reduction was accomplished by inhibiting the induction of integrins, integrin-associated proteins of paxillin and gelsolin, cdc42 and CD44 involved in the formation of actin rings. The inhibition of integrin-mediated actin ring formation by linarin and acacetin entailed the disruption of TRAF6-c-Src-PI3K signaling of bone-resorbing osteoclasts. The functional inhibition of c-Src was involved in the loss of F-actin-enriched podosome core protein cortactin-mediated actin assembly due to linarin and acacetin.

CONCLUSION

These observations demonstrate that CSE, linarin and acacetin were effective in retarding osteoclast function of focal adhesion to bone matrix and active bone resorption via inhibition of diffuse cloud-associated αvβ3 integrin and core-linked CD44.

Systematic analysis of miRNAs in patients with postmenopausal osteoporosis

MicroRNAs (miRNAs) represent RNA species found in serum. Many miRNAs were observed that were related to osteoporosis and osteopenia. However, expression and function analysis of miRNAs in postmenopausal osteoporosis (PMOP) remain unaddressed. We first compared the miRNA expression of blood samples in postmenopausal women with osteopenia or with osteoporosis via analysis of GSE64433. Bioinformatics analyses were conducted to get the key miRNAs and their functions and pathways. 331 miRNAs were being identified as differentially expressed miRNAs. Among these, 122 miRNA (36.86%) were up-regulated, and the remaining 209 miRNAs (63.14%) were down-regulated. 105 genes were predicted as the targets of these miRNAs. GO enrichment analysis results showed that the miRNAs mainly enriched in DNA binding, ATP binding, gene expression, regulation of the apoptotic process, chromatin binding, and protein kinase binding. KEGG enrichment analysis results demonstrated that the miRNAs mainly enriched in the TGF beta signaling pathway, wnt signaling pathway, JAK-STAT signaling pathway, and androgen receptor signaling pathway. This study identified the abundant differentially expressed miRNAs in the blood samples of postmenopausal women with osteopenia or with osteoporosis. This study may contribute to getting new diagnostic and therapeutic strategies for PMOP.

Downregulating microRNA-152-3p promotes the viability and osteogenic differentiation of periodontal ligament stem cells via targeting integrin alpha 5

OBJECTIVE

The aim of this study was to investigate the role of microRNA-152-3p (miR-152-3p) in the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs).

DESIGN

HPDLSCs were isolated and identified using immunofluorescence staining, and their osteogenic differentiation capability was evaluated by alkaline phosphatase staining and Alizarin Red staining. HPDLSC viability was measured using cell counting kit-8. alkaline phosphatase level in hPDLSCs was measured by enzyme-linked immunosorbent assay. Target gene and potential binding sites between miR-152-3p and integrin alpha 5 (ITGA5) were predicted using TargetScan and confirmed by dual-luciferase reporter assay. Relative expressions of miR-152-3p and factors related to hPDLSC osteogenic differentiation were measured by quantitative real-time polymerase chain reaction and Western blot as needed.

RESULTS

Collected cells were observed and identified as hPDLSCs. MiR-152-3p expression was downregulated during hPDLSC osteogenic differentiation in a time-dependent manner, and downregulating miR-152-3p promoted cell viability, enhanced alkaline phosphatase level, and increased the expressions of genes related to hPDLSC osteogenic differentiation. ITGA5 was the target gene of miR-152-3p and ITGA5 expression was upregulated during osteogenic differentiation in a time-dependent manner. Silencing ITGA5 partially reversed the effects of downregulating miR-152-3p on hPDLSCs.

CONCLUSION

Downregulating miR-152-3p may promote hPDLSC viability and osteogenic differentiation via targeting ITGA5, and have potential effects on periodontal and alveolar bone regeneration.

FOXO3 is targeted by miR-223-3p and promotes osteogenic differentiation of bone marrow mesenchymal stem cells by enhancing autophagy

Mesenchymal stem cells (MSCs) are a promising regenerative medicine. The roles of miRNAs in osteogenic differentiation of bone marrow MSCs (BM-MSCs) remained less reported. Forkhead Box O3 (FOXO3) and alkaline phosphatase (ALP) levels in the BM-MSCs were measured on 3, 7, and 14 days after osteogenic differentiation. After transfection of FOXO3 overexpression plasmids or siFOXO3 into BM-MSCs, factors related to osteogenic differentiation or cell autophagy were determined. Besides, 3-methyladenine or rapamycin, as well as miR-223-3p mimic or inhibitor were applied to further determine the effect of FOXO3 in BM-MSCs. FOXO3 and ALP levels were increased in a time-dependent manner with osteogenic differentiation, supported by Alizarin Red Staining. Furthermore, up-regulated FOXO3 increased levels of ALP and factors related to osteogenic differentiation by increasing levels of autophagy-related factors. FOXO3, targeted by miR-223-3p, reversed the effects of miR-223-3p on factors related to BM-MSC autophagy and osteogenic differentiation. Down-regulated miR-223-3p expression promoted osteogenic differentiation of BM-MSCs by enhancing autophagy via targeting FOXO3, suggesting the potential of miR-223-3p as a therapeutic target for enhancing bone functions.

Chrysanthemum indicum L.: A Comprehensive Review of its Botany, Phytochemistry and Pharmacology

Chrysanthemum indicum L. (C. indicum L.), a member of the Compositae family, is a perennial plant that has been used as a traditional medicine for more than 2000 years in China and is widely used for the treatment of Pemphigus, swelling, pain, and scrofula. To date, more than 190 chemical constituents have been isolated and identified from this plant, including flavonoids, terpenoids, phenylpropanoids, and phenolic acids. Numerous modern studies have shown that extracts or monomeric compounds from C. indicum L. have several pharmacological activities, such as anti-inflammatory anti-oxidation, antipathogenic microorganism, anticancer, immune regulation, and hepatoprotective effects. However, resource availability, the research on the mechanism, and quality control are still insufficient, which deserves further efforts. In this paper, the advances in botany, phytochemistry, and pharmacology of C. indicum L were reviewed. We hope that this review can provide important information for traditional Chinese medicine, phytochemistry, synthetic and medicinal chemistry researchers for making full use of C. indicum L. resource.

MiR-151a-3p Promotes Postmenopausal Osteoporosis by Targeting SOCS5 and Activating JAK2/STAT3 Signaling

Postmenopausal osteoporosis, the most common type of primary osteoporosis, poses a significant threat to women's health worldwide. However, detailed molecular mechanism and therapeutic strategy for postmenopausal osteoporosis remain insufficient. Increasing evidence suggests that microRNAs contributed to the pathogenesis of osteoporosis and could be considered as potential therapeutic targets. In this study, we found that miR-151a-3p was upregulated in osteoporosis samples. Experiments in MC3T3-E1 cells indicated that miR-151a-3p significantly inhibited cell viability and promoted lactate dehydrogenase release, as well as increased RANKL/OPG ratio and decreased Runx2 and BMP2 expressions. SOCS5 was identified as a direct target gene of miR-151a-3p, which was confirmed by luciferase reporter assay. Moreover, an inverse correlation between miR-151a-3p and SOCS5 was observed in osteoporosis femurs. In addition, JAK2/STAT3 pathway was found to be involved in the progress of osteoporosis mediated by miR-151a-3p-SOCS5 axis. In vivo, ovariectomized (OVX) rat model was established to simulate postmenopausal osteoporosis. The results revealed that miR-151a-3p significantly decreased the bone mineral density and biomechanical parameters of femurs in OVX rats by targeting SOCS5, and that JAK2/STAT3 pathway is a downstream target of miR-151a-3p-SOCS5 axis in OVX rats. In conclusion, our findings suggested that miR-151a-3p contributed to the pathogenesis of postmenopausal osteoporosis, and promoted its progress by targeting SOCS5 and activating JAK2/STAT3 signaling. Thus, anti-miR-151a-3p could be a potential therapeutic strategy for postmenopausal osteoporosis.

Pinoresinol promotes MC3T3‑E1 cell proliferation and differentiation via the cyclic AMP/protein kinase A signaling pathway

Estradiol (E2) is a first‑line drug for osteoporosis (OP) treatment via promotion of osteoblastic proliferation and differentiation. However, a long‑term use of E2 would produce side effects thus, it is imperative to discover safer and more effective drugs. Pinoresinol (PINO) has a similar chemical structure to E2. The present study aimed to investigate whether PINO could promote osteoblastic proliferation and differentiation and the potential mechanisms. After treatment with 0.1 µg/l PINO for 2 days, MC3T3‑E1 cell migration was assessed by wound healing assay. Estrogen (E2) treatment served as a positive control. RT‑qPCR and western blotting were used for mRNA and protein expression analyses. Alkaline phosphatase (ALP) activity assay and Alizarin red staining were performed to investigate the calcification and mineralization, and the cyclic AMP (cAMP) level was detected by enzyme‑linked immunosorbent assay (ELISA). H89, an inhibitor of protein kinase A (PKA), was introduced to verify the role of cAMP/PKA in the effect of PINO on MC3T3‑E1 cells. Cell viability was the highest under 48 h of 0.1 µg/l PINO treatment. After treatment with PINO, a significant increase was observed in the migration rate and the expression of collagen type I (Col‑I), ALP, osteopontin (OPN), runt‑related transcription factor 2 (Runx2) and bone morphogenetic protein‑2 (BMP‑2) (P<0.01). The ALP activity and Alizarin red size in PINO and E2 groups were notably increased. The increased cAMP, PKA and phosphorylated cAMP response element‑binding protein (CREB) levels were also observed in the PINO group. Furthermore, H89 co‑treatment abolished the positive effects of PINO on cell viability and migration. PINO had similar effects to E2 on the osteoblastic proliferation and differentiation, and these positive effects may be attributed to the regulation of the cAMP/PKA signaling pathway.

Silibinin A decreases statin‑induced PCSK9 expression in human hepatoblastoma HepG2 cells

Hypercholesterolemia is one of the major risk factors for the occurrence and development of atherosclerosis. The most common drugs used to treat hypercholesterolemia are 3‑hydroxy‑3‑methyl‑glutaryl‑CoA reductase inhibitors, known as statins. Statins induce a beneficial increase in the levels of the low density lipoprotein receptor (LDLR) and additionally upregulate proprotein convertase subtilisin/kexin type 9 (PCSK9), which leads to LDLR degradation. This process causes a negative feedback response that attenuates the lipid lowering effects of statins. Therefore, the development of PCSK9 inhibitors may increase the lipid‑lowering functions of statins. In the present study, a drug‑screening assay was developed using the human PCSK9 promoter, based on data from a dual‑luciferase reporter assay, and the efficacies of various compounds from Traditional Chinese Medicine were examined. Among the compounds examined, SIL was demonstrated to function by targeting PCSK9. It was identified that SIL treatment decreased the expression levels of PCSK9 in HepG2 cells by decreasing the activity of the PCSK9 promoter in a dose‑and time‑dependent manner. Notably, SIL antagonized the statin‑induced phosphorylation of the p38 MAPK signaling pathway. The present study suggested that SIL may be developed as a novel PCSK9 inhibitor that may increase the efficiency of statin treatment.

Effect of different concentration of demineralized bone powder with gellan gum porous scaffold for the application of bone tissue regeneration

The prevalence of bone-related diseases has increased, the population growth as a result of the aging phenomenon requires more effective treatments for regeneration of bone defect. Although an autogenous bone graft was used in traditional operation method, they are very inefficient in current bone defect surgery and very difficult to gather the required amount of bone for operation. It is becoming a gradually growing disease, hence there is a need for developing a new method for preparing biomimetic scaffolds. DBP (demineralized bone powder), a potent bone regeneration material, has a trace amount of ions and bone mineral component. Especially, GD (Gallus gallus var domesticus) DBP has a unique property, which has melanin, for strengthening bones, increasing ALP activity and bone mineralization, compared to other available biomaterials. For that reason, GD DBP was combined with GG (gellan gum). The material was characterized in vitro and in vivo rat model. The first priority in this work was given to assessing the attachment and proliferation rates of BMSCs following the in vivo experiment in rats. The results of 1% sample showed better osteogenic effects that can be used in clinical application after studying in larger animals for better bone regeneration and tissue engineering.

Effects of hydrogen peroxide on biological characteristics and osteoinductivity of decellularized and demineralized bone matrices

Due to the similar collagen composition and closely physiological relationship with soft connective tissues, demineralized bone matrices (DBMs) were used to repair the injured tendon or ligament. However, the osteoinductivity of DBMs would be a huge barrier of these applications. Hydrogen peroxide (H₂ O₂ ) has been proved to reduce the osteoinductivity of DBMs. Nevertheless, the biological properties of H₂ O₂ -treated DBMs have not been evaluated completely, while the potential mechanism of H₂ O₂ compromising osteoinductivity is also unclear. Hence, the purpose of this study was to characterize the biological properties of H₂ O₂ -treated DBMs and search for the proof that H₂ O₂ could compromise osteoinductivity of DBMs. Decellularized and demineralized bone matrices (DCDBMs) were washed by 3% H₂ O₂ for 12 h to fabricate the H₂ O₂ -treated DCDBMs (HPTBMs). Similar biological properties including collagen, biomechanics, and biocompatibility were observed between DCDBMs and HPTBMs. The immunohistochemistry staining of bone morphogenetic protein 2 (BMP-2) was negative in HPTBMs. Furthermore, HPTBMs exhibited significantly reduced osteoinductivity both in vitro and in vivo. Taken together, these findings suggest that the BMP-2 in DCDBMs could be the target of H₂ O₂ . HPTBMs could be expected to be used as a promising scaffold for tissue engineering. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Promotion of osteogenic differentiation by non-thermal biocompatible plasma treated chitosan scaffold

Non-thermal biocompatible plasma (NBP) has recently emerged as an attractive tool for surface modification of biomaterials in tissue engineering. Three dimensional chitosan scaffolds have been widely used in bone tissue engineering due to biodegradable and biocompatible properties. The present study aimed to evaluate osteogenic potential of NBP treated chitosan scaffold. The surface characteristics of scaffolds were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), cell proliferation and differentiation was tested with osteoprogenitor cell line MC3T3-E1. The results show that NBP modified scaffold increase cell metabolic by MTT assay and live/dead assay. More importantly, we evidenced enhancement of osteogenic differentiation on NBP treated scaffolds by an increase of alkaline phosphatase (ALP) activity, high degree of extracellular mineralization and up-regulated osteogenic marker genes expression level. The findings in our study highlighted NBP as the innovative method to modified chitosan scaffold and to fine-tuning the scaffold a more suitable and beneficial biomaterial for in vivo bone tissue engineering and clinical bone defects therapies.

Hypoglycemic effect of standardized Chrysanthemum zawadskii ethanol extract in high-fat diet/streptozotocin-induced diabetic mice and rats

Chrysanthemum zawadskii (CZ) is a perennial herb belonging to the Asteraceae family. CZ is used medicinally to treat inflammatory and uterine diseases in Asia. CZ was extracted with 50% ethanol and CZ extract (CZE; at 125, 250, and 500 mg/kg body weight) was administered orally every day for 5 or 6 weeks to investigate the anti-diabetic effects in streptozotocin (STZ)-induced rats and STZ + high-fat diet (HFD)-fed mice. CZE significantly decreased fasting blood glucose levels in STZ- and STZ + HFD-induced diabetic models. In addition, glucose tolerance and insulin tolerance were improved in the STZ + HFD + CZE group by increasing insulin levels and decreasing hemoglobin A1c (HbA1c) levels in serum. Furthermore, CZE supplements decreased components of the serum lipid profile such as triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels. These results suggest that CZE may be a potential candidate for controlling hyperglycemia.

miR-205 targets runt-related transcription factor 2 to inhibit human pancreatic cancer progression

Previous studies have demonstrated that microRNAs (miRs) serve important roles in the progression of human cancer types, including pancreatic cancer (PC), a highly lethal malignancy. In the past few decades, several miRs have been identified to be associated with the overall survival of patients with PC and have been demonstrated to be potential therapeutic targets. However, to the best of our knowledge, the association between miR-205 expression and the progression of PC has rarely been investigated. In the current study, low miR-205 expression was revealed in PC tumor tissues and indicated poor prognosis in patients with PC. In addition, miR-205 overexpression reduced and miR-205 depletion enhanced PC cell proliferation and migration in vitro. Using bioinformatics, a luciferase reporter assay and western blot analyses, the current study identified that runt-related transcription factor 2 (RUNX2) was a target of miR-205 in PC and overexpression of miR-205 suppressed the expression of RUNX2. Notably, overexpression of RUNX2 partially reversed the inhibitory effect of miR-205 on PC cell proliferation and migration in vitro. Therefore, the results of the present study revealed that miR-205 functions as a tumor suppressor in PC by targeting RUNX2.

Effect of graded calcium supplementation in low-nutrient density feed on tibia composition and bone turnover in meat ducks

Both genetic selection and increasing nutrient density for improving growth performance had inadvertently increased leg problems of meat ducks, which adversely affects animal welfare. We hypothesised that slowing weight gain with improving tibia quality probably enhanced tibial mechanical properties and alleviated leg deformities. Therefore, the present study aimed to evaluate the effect of graded Ca supplementation in a low-nutrient density (LND) diet on tibia composition and bone turnover in meat ducks. A total of 720 15-d-old male meat ducks were randomly assigned and fed a standard nutrient density positive control (PC) diet containing 0·9 % Ca, and four LND diets with 0·5, 0·7, 0·9 and 1·1 % Ca, respectively. Ducks fed the 0·5 % Ca LND diet and the PC diet had higher incidence of tibial dyschondroplasia (TD). When compared with the 0·5 % Ca LND diet, LND diets with ≥0·7 % Ca significantly improved tibia composition, microarchitecture and mechanical properties, and consequently decreased the incidence of TD. Furthermore, LND diets with ≥0·7 % Ca increased osteocyte-specific gene mRNA expression, blocked the expression of osteoblast differentiation marker genes including osteocalcin, collagenase-1 and alkaline phosphatase (ALP), and also decreased the expression of osteoclast differentiation genes, such as vacuolar-type H+-ATPase, cathepsin K and receptor activator of NF-κB. Meanwhile bone markers such as serum ALP, osteocalcin (both osteoblast markers) and tartrate-resistant acid phosphatase (an osteoclast marker) were significantly decreased in at least 0·7 % Ca treated groups. These findings indicated that LND diets with ≥0·7 % Ca decreased bone turnover, which subsequently increased tibia quality for 35-d-old meat ducks.

Syringic acid, a phenolic acid, promotes osteoblast differentiation by stimulation of Runx2 expression and targeting of Smad7 by miR-21 in mouse mesenchymal stem cells

Syringic acid (SA), a phenolic acid, has been used in Chinese and Indian medicine for treating diabetes but its role in osteogenesis has not yet been investigated. In the present study, at the molecular and cellular levels, we evaluated the effects of SA on osteoblast differentiation. At the cellular level, there was increased alkaline phosphatase (ALP) activity and calcium deposition by SA treatment in mouse mesenchymal stem cells (mMSCs). At the molecular level, SA treatment of these cells stimulated expression of Runx2, a bone transcription factor, and of osteoblast differentiation marker genes such as ALP, type I collagen, and osteocalcin. It is known that Smad7 is an antagonist of TGF-β/Smad signaling and is a negative regulator of Runx2. microRNAs (miRNAs) play a key role in the regulation of osteogenesis genes at the post-transcriptional level and studies have reported that Smad7 is one of the target genes of miR-21. We found that there was down regulation of Smad7 and up regulation of miR-21 in SA-treated mMSCs. We further identified that the 3'-untranslated region (UTR) of Smad7 was directly targeted by miR-21 in these cells. Thus, our results suggested that SA promotes osteoblast differentiation via increased expression of Runx2 by miR-21-mediated down regulation of Smad7. Hence, SA may have potential in orthopedic applications.

Signalling Alterations in Bones of Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) Gene Deficient Mice

Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with diverse developmental roles, including differentiation of skeletal elements. It is a positive regulatory factor of chondrogenesis and osteogenic differentiation in vitro, but little is known about its in vivo role in bone formation. In our experiments, diaphyses of long bones from hind limbs of PACAP gene-deficient mice showed changes in thickness and increased staining intensity. Our main goal was to perform a detailed morphological and molecular biological analysis of femurs from PACAP knockout (KO) and wild type (WT) mice. Transverse diameter and anterior cortical bone thickness of KO femurs showed significant alterations with disturbed Ca²⁺ accumulation and collagen type I expression. Higher expression and activity of alkaline phosphatase were also observed, accompanied by increased fragility PACAP KO femurs. Increased expression of the elements of bone morphogenic protein (BMP) and hedgehog signalling was also observed, and are possibly responsible for the compensation mechanism accounting for the slight morphological changes. In summary, our results show that lack of PACAP influences molecular and biomechanical properties of bone matrix, activating various signalling cascade changes in a compensatory fashion. The increased fragility of PACAP KO femur further supports the role of endogenous PACAP in in vivo bone formation.

Chinese single herbs and active ingredients for postmenopausal osteoporosis: From preclinical evidence to action mechanism

Postmenopausal osteoporosis is a systemic metabolic skeletal disease generally ascribable to a dearth of estrogen. Whether traditional Chinese medicine is effective in management of postmenopausal osteoporosis remains unclear. This article reviews the experimental evidence of both in vitro and in vivo preclinical studies with the theme of the application of Chinese single herbs and active ingredients in postmenopausal osteoporosis. It includes three single herbs (Herba Epimedium, Rhizoma Drynariae, and Salvia miltiorrhiza) and eight active ingredients (saikosaponins, linarin, echinacoside, sweroside, psoralen, poncirin, vanillic acid, and osthole). The experimental studies indicated their potential use as treatment for postmenopausal osteoporosis and investigated the underlying mechanisms including osteoprotegerin/receptor activator of nuclear factor κB ligand (OPG/RANKL), extracellular-signal-regulated kinase/c-Jun N terminal kinase/mitogen-activated protein kinase (ERK/JNK/MAPK), estrogen receptor (ER), bone morphogenetic protein (BMP), transforming growth factor (TGF)-β, Wnt/β-catenin, and Notch signaling pathways. This review contributes to a better understanding of traditional Chinese medicine and provides useful information for the development of more effective anti-osteoporosis drugs.

Inhibitory activity of linarin on osteoclastogenesis through receptor activator of nuclear factor κB ligand-induced NF-κB pathway

Linarin, a natural flavonoid glycoside widely found in plants, has been reported to possess anti-inflammation, neuroprotection and osteogenic properties. However, its impact on osteoclast remains unclear. In the present study, the effects of linarin on osteoclastogenesis and its underlying molecular mechanisms of action were investigated. Using the culture systems of osteoclasts derived from bone marrow macrophages (BMMs), we found that linarin dose-dependently inhibited osteoclasts formation and bone resorptive activity. The Cell Counting Kit-8 test displayed that the viability of cells was not influenced by linarin at doses up to 10 μg/mL. In addition, linarin downregulated osteoclast-related genes expression, including nuclear factor of activated T cells cytoplasmic 1 (NFATc1), tartrate resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR) and c-Fos, as shown by quantitative real time polymerase chain reaction (RT-qPCR). Western blot analysis further showed that linarin inhibited receptor activator of nuclear factor κB ligand (RANKL)-induced nuclear factor kappa B (NF-κB) p65 and NFATc1 activity. The present findings show that linarin exerted a potent inhibitory effect on osteoclastogenesis through RANKL-induced NF-κB signaling pathway. In conclusion, the results suggest that linarin has anti-osteoclastic effects and may serve as potential modulatory agents for the prevention and treatment of bone loss-associated diseases.

Down-regulation of Noggin and miR-138 coordinately promote osteogenesis of mesenchymal stem cells

Mesenchymal stem cells (MSCs) can differentiate to osteocytes under suitable conditions. In recent years, micro-nucleotides have been progressively used to modulate gene expression in cells due to the consideration of safety. Our present study aimed to investigate whether co-delivery of Noggin-siRNA and antimiR-138 enhances the osteogenic effect of MSCs. Using a murine MSC line, C3H/10T1/2 cells, the delivery efficiency of Noggin-siRNA and antimiR-138 into MSCs was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Cell phenotype and proliferation capacity was assessed by flow cytometry and MTT assay respectively. The osteogenesis of MSCs was tested by Alkaline Phosphatase (ALP) staining, qRT-PCR, and western blot analyses. Our results demonstrated that the expression of Noggin and miR-138 were significantly silenced in MSCs by Noggin-siRNA and/or antimiR-138 delivery, while the phenotype and proliferation capacity of MSCs were not affected. Down-regulation of Noggin and miR-138 cooperatively promoted osteogenic differentiation of MSCs. The ALP positive cells reached about 83.57 ± 10.18%. Compared with single delivery, the expression of osteogenic related genes, such as Alp, Col-1, Bmp2, Ocn and Runx2, were the highest in cells with co-delivery of the two oligonucleotides. Moreover, the protein level of RUNX2, and the ratios of pSMAD1/5/SMAD1/5 and pERK1/2/ERK1/2 were significantly increased. The activation of Smad, Erk signaling may constitute the underlying mechanism of the enhanced osteogenesis process. Taken together, our study provides a safe strategy for the clinical rehabilitation application of MSCs in skeletal deficiency.

Linarin sensitizes tumor necrosis factor-related apoptosis (TRAIL)-induced ligand-triggered apoptosis in human glioma cells and in xenograft nude mice

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) is reported as a promising anti-cancer therapeutic agent. Nevertheless, a variety of cancer cells, including human malignant glioma cells, are resistant to TRAIL treatment, indicating that it is necessary to find effective strategies to overcome the TRAIL resistance. Linarin (LIN), a natural flavonoid compound in Flos Chrysanthemi Indici (FCI), has been exhibited to exert various pharmacological activities, including anti-cancer. Here in our study, we found that non-cytotoxic doses of LIN (5μM) dramatically potentiated TRAIL (80ng/ml)-induced cytotoxicity (52.36±1.58%) and apoptosis (68.50±1.23%) using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and flow cytometry assays, respectively, in human glioma cells of U87MG. Apoptosis was evidenced by enhanced cleavage of Caspase-8/-9/-3 and poly (ADP-ribose) polymerase (PARP), and reduced anti-apoptotic proteins, including B-cell leukemia/lymphoma 2 (Bcl-2), mantle cell lymphoma (Mcl)-1, and Survivin. Moreover, both intrinsic and extrinsic apoptosis pathways were included in apoptosis induced by LIN and TRAIL co-treatment, along with high release of Cyto-c into cytoplasm and enhancement of fas-associated protein with death domain (FADD), death-inducing signaling complex (DISC), death receptor 4 (DR) 4 and DR5, respectively. Reactive oxygen species (ROS) generation, up to 39.86±2.32%, was also highly triggered by TRAIL and LIN combinational treatment, which was accompanied with high phosphorylation of c-Jun-N-terminal kinase (JNK). In vivo, TRAIL and LIN double treatment significantly reduced the tumor growth using xenograft tumor model through inducing apoptosis. We demonstrated that combining LIN with TRAIL treatments might be effective against TRAIL-resistant glioma cells through inducing apoptosis regulated by ROS generation.

Enhanced bone repair induced by human adipose-derived stem cells on osteogenic extracellular matrix ornamented small intestinal submucosa

AIM

Our aim was to design an osteogenic extracellular matrix (ECM) coated bioscaffold and to apply it to critical bone defect repair with adipose-derived stem cells (ADSCs).

MATERIALS & METHODS

Morphology of scaffolds was scanned by scanning electron microscope. Cell adhesion, proliferation and osteogenic differentiation of ADSCs on ECM-small intestinal submucosa (SIS) were evaluated by immunofluorescences staining, cell counting kit-8 and real-time qPCR, respectively. A mouse calvarial defect model was used to assess effects on bone regeneration in vivo.

RESULTS

Abundant ECM was coated on SIS, which facilitated cell adhesion and proliferation of ADSCs. ECM-SIS induced osteogenic differentiation of ADSCs even without osteogenic inductive factors. Bone regeneration in vivo was enhanced by ECM-SIS + ADSCs via BMP/SMAD pathway.

CONCLUSION

This work suggested a biofabricated SIS scaffold coated with osteogenic ECM-facilitated bone regeneration with ADSCs synergistically.

Can a Biodegradable Implanted Bilayered Drug Delivery System Loaded with BMP-2/BMP-12 Take an Effective Role in the Biological Repair Process of Bone-Tendon Injuries? A Preliminary Report

Background

Use of biodegradable and biocompatible materials in the orthopedic surgery is gaining popularity. In this research, the rate of controlled release of a bilayered prototype biomaterial designed to promote osteoblastic and tenoblastic activity was calculated using pharmacochemical methods.

Methods

The first part of the design, composed of a sodium tetraborate, polyvinyl alcohol, and starch based hydrogel, was loaded with bone morphogenic protein-2. The second part which was composed of a sodium tetraborate, polyvinyl alcohol, and chitosan based hydrogel was loaded with bone morphogenic protein-12. Osteochondral and tendon tissue specimens were obtained from patients with a diagnosis of gonarthrosis and primary bone cells and tendon cells cultures were prepared following treatment with collagenase enzyme. Cell samples were collected from the groups by means of an invert light microscope and environmental scanning electron microscope underwent at the 1st and 21st days. The level of osteogenic differentiation was measured by the activity of alkaline phosphatase. For the statistical evaluation of the obtained data, groups were compared with post hoc Tukey test following analysis of variance. Level of significance was accepted to be <0,01.

Results

Both osteogenic and tenogenic stimulation were observed in the cultured specimens. In comparison to the control groups, the rate of proliferation of healthy cells was found to be higher in the groups to which the design was added (p < 0.01).

Conclusions

Our research is a preliminary report that describes a study conducted in an in vitro experimental setting. We believe that such prototype systems may be pioneers in targeted drug therapies after reconstructional surgeries.

Calcium Supplement Derived from Gallus gallus domesticus Promotes BMP-2/RUNX2/SMAD5 and Suppresses TRAP/RANK Expression through MAPK Signaling Activation

The present study evaluated the effects of a calcium (Ca) supplement derived from Gallus gallus domesticus (GD) on breaking force, microarchitecture, osteogenic differentiation and osteoclast differentiation factor expression in vivo in Ca-deficient ovariectomized (OVX) rats. One percent of Ca supplement significantly improved Ca content and bone strength of the tibia. In micro-computed tomography analysis, 1% Ca supplement attenuated OVX- and low Ca-associated changes in bone mineral density, trabecular thickness, spacing and number. Moreover, 1% Ca-supplemented diet increased the expression of osteoblast differentiation marker genes, such as bone morphogenetic protein-2, Wnt3a, small mothers against decapentaplegic 1/5/8, runt-related transcription factor 2, osteocalcin and collagenase-1, while it decreased the expression of osteoclast differentiation genes, such as thrombospondin-related anonymous protein, cathepsin K and receptor activator of nuclear factor kappa B. Furthermore, 1% Ca-supplemented diet increased the levels of phosphorylated extracellular signal-regulated kinase and c-Jun N-terminal kinase. The increased expression of osteoblast differentiation marker genes and activation of mitogen-activated protein kinase signaling were associated with significant increases in trabecular bone volume, which plays an important role in the overall skeletal strength. Our results demonstrated that 1% Ca supplement inhibited osteoclastogenesis, stimulated osteoblastogenesis and restored bone loss in OVX rats.

Preparative Purification of Bioactive Compounds from Flos Chrysanthemi Indici and Evaluation of Its Antiosteoporosis Effect

To understand the material basis and underlying molecular machinery of antiosteoporosis activity of the Flos Chrysanthemi Indici (FCI), the consequences of ethanol extract on the bone loss in mice induced due to ovariectomy (OVX) was evaluated. Also, the antiosteoporosis fraction obtained from the FCI ethanol extract was isolated and purified using a preparative high-speed countercurrent chromatography (HSCCC). The in vitro impact of the compounds was investigated on osteoblast proliferation and differentiation. The results revealed that ethyl acetate fraction with robust in vivo antiosteoporosis activity was obtained. The important compounds purified by HSCCC using gradient elution system included acacetin, apigenin, luteolin, and linarin. The four compounds enhanced the differentiation and proliferation of osteoblasts in MC3T3-E1 cells. They also augmented the mRNA levels of runt-related transcription factor 2 (Runx2), osteocalcin (OCN), osteopontin (OPN), and type I collagen (COL I). The AKT signaling pathway was also activated in MC3T3-E1 cells by the four compounds. The present study demonstrated that the antiosteoporosis effects of FCI did not depend on a single component, and HSCCC efficiently isolated and purified the antiosteoporosis bioactive compounds from FCI.

RUNX2 promotes hepatocellular carcinoma cell migration and invasion by upregulating MMP9 expression

Runt-related transcription factor 2 (RUNX2) was first identified as a transcription factor to play an important role in different biological processes of osteoblast and chondrocyte, including differentiation and migration. Recently, RUNX2 has been implicated in promigratory/proinvasive behavior in different human malignancies. In the present study, we demonstrated that the RUNX2 mRNA and protein expression were both increased significantly in HCC tissues and cell lines. High RUNX2 expression was correlated obviously with poor clinicopathological characteristics including multiple tumor nodes, high histological grading, venous infiltration and advanced tumor-node-metastasis (TNM) stage. In addition, we demonstrated that RUNX2 was a prognostic indicator for predicting 5-year overall survival and disease-free survival of HCC patients. Our studies showed that RUXN2 overexpression promoted, while RUNX2 knockdown inhibited HCC cell migration and invasion in vitro. Notably, RUNX2 positively regulated matrix metalloproteinase 9 (MMP9) accumulation in HCC cells. Furthermore, we confirmed that RUNX2 was positively correlated with MMP9 expression in HCC tissues by Pearson correlation analysis. Mechanistically, we demonstrated that MMP9 overexpression increased HCC cell migration and invasion, while MMP9 knockdown reduced HCC cell migration and invasion in vitro. Alteration of MMP9 expression partially abrogated the effects of RUNX2 on HCC cell migration and invasion, which suggests that RUNX2 developed its pro-metastatic biological function by upregulating the expression of MMP9 in HCC cells. In conclusion, our results reveal that RUNX2 promotes HCC cell migration and invasion by MMP9-mediated pathway, and potentially serves as a new prognostic biomarker and in therapeutic strategies for HCC.