Anti-inflammatory effect of luteoloside against methylglyoxal induced human dental pulp cells.

PURPOSE: The aim of this study was to investigate whether luteoloside, a flavonoid, could protect human dental pulp cells (HDPCs) against inflammation and oxidative stress induced by methylglyoxal (MGO), one of the advanced glycated end products (AGE) substances. METHODS: HDPCs were stimulated with MGO and treated with luteoloside. MTT assay was used to determine cell viability. Protein expression was measured via western blotting. Reactive oxygen species (ROS) were measured with a Muse Cell Analyzer. Alkaline phosphatase activity (ALP) and Alizarin red staining were used for mineralization assay. RESULTS: Luteoloside down-regulated the expression of inflammatory molecules such as ICAM-1, VCAM-1, TNF-α, IL-1ß, MMP-2, MMP-9, and COX-2 in MGO-induced HDPCs without showing any cytotoxicity. It attenuated ROS formation and enhanced osteogenic differentiation such as ALP activity and Alizarin red staining in MGO-induced HDPCs. Overall, luteoloside showed protective actions against inflammation and oxidative stress in HDPCs induced by MGO through its anti-inflammatory, anti-oxidative, and osteogenic activities by down-regulating p-JNK in the MAPK pathway. CONCLUSION: These results suggest that luteoloside might be a potential adjunctive therapeutic agent for treating pulpal pathological conditions in patients with diabetes mellitus.

Insulin growth factor binding protein-3 enhances dental implant osseointegration against methylglyoxal-induced bone deterioration in a rat model.

PURPOSE: The aim of this study was to determine the effect of insulin growth factor binding protein-3 (IGFBP-3) on the inhibition of glucose oxidative stress and promotion of bone formation near the implant site in a rat model of methylglyoxal (MGO)-induced bone loss. METHODS: An in vitro study was performed in MC3T3 E1 cells treated with chitosan gold nanoparticles (Ch-GNPs) conjugated with IGFBP-3 cDNA followed by MGO. An in vivo study was conducted in a rat model induced by MGO administration after the insertion of a dental implant coated with IGFBP-3. RESULTS: MGO treatment downregulated molecules involved in osteogenic differentiation and bone formation in MC3T3 E1 cells and influenced the bone mineral density and bone volume of the femur and alveolar bone. In contrast, IGFBP-3 inhibited oxidative stress and inflammation and enhanced osteogenesis in MGO-treated MC3T3 E1 cells. In addition, IGFBP-3 promoted bone formation by reducing inflammatory proteins in MGO-administered rats. The application of Ch-GNPs conjugated with IGFBP-3 as a coating of titanium implants enhanced osteogenesis and the osseointegration of dental implants. CONCLUSIONS: This study demonstrated that IGFBP-3 could be applied as a therapeutic component in dental implants to promote the osseointegration of dental implants in patients with diabetes, which affects MGO levels.

Nasal obstruction promotes alveolar bone destruction in the juvenile rat model.

BACKGROUND/PURPOSE: Nasal obstruction leads to oral breathing and consequently hypoxia. The purpose of this study was to determine the influence of hypoxia on inflammatory response and the effect on alveolar bone development in a rat model in which mouth breathing was induced by nasal obstruction. MATERIALS AND METHODS: Unilateral nasal obstruction was performed by injecting a Merocel sponge into the nasal cavity of 8-week-old Sprague Dawley (SD) rats. After 3 and 6 weeks of nasal obstruction, rats were sacrificed, the organs were weighed, and the changes in mandibular bone quality were examined by micro-computed tomography (µ-CT). The stereomicroscope was used for the morphological analysis of alveolar bone loss in response to nasal obstruction. Hematoxylin and Eosin (H&E) and immunohistochemical staining were employed to examine inflammation and bone remodeling induced by hypoxia. RESULTS: Nasal obstruction led to a delay in overall growth and organ development. The bone mineral density (BMD) and bone volume/total volume (BV/TV) of the mandible were reduced due to nasal obstruction, and the loss of the alveolar bone was confirmed morphologically. Our nasal obstruction method was observed to be successful in inducing hypoxia along with an increase in hypoxia-inducible factor 1-alpha (HIF-α). Oral hypoxia induced by nasal obstruction increased inflammatory response, and increased expression of receptor activator of nuclear factor kappa-Β ligand (RANKL) led to bone destruction. CONCLUSION: This study demonstrated that nasal obstruction induced mouth breathing led to hypoxia in a rat model. Under hypoxic conditions, an increase in osteoclast differentiation induced by activation of the inflammatory pathway causes destructive changes in the alveolar bone.

Mussel adhesive protein blended with gelatin loaded into nanotube titanium dental implants enhances osseointegration.

The purpose of this study was to investigate whether mussel adhesive protein (MAP) blended with gelatin loaded into nanotube titanium (Ti) dental implants enhances osseointegration and supports bone formation. Cell viability, crystal violet staining, Western blot analysis, alizarin red S staining, alkaline phosphatase (ALP) activity, micro-computed tomography (µ-CT), hematoxylin and eosin (H&E), and immunohistochemistry (IHC) staining were employed to test the biocompatibility of MAP blended with gelatin (MAP/Gel). MC3T3 E1 cells were used for in vitro and Sprague-Dawley rats for in vivo models in this study. MC3T3 E1 cells cultured in MAP/Gel loaded into nanotube Ti surface demonstrated activation of FAK-PI3K-MAPKs-Wnt/ß-catenin signaling pathway and enhanced osteogenic differentiation. µ-CT, H&E, and IHC staining confirmed that MAP/Gel dental implants promoted bone regeneration around the nanotube Ti implants by upregulation of Runx-2, BMP-2/7, Osterix, and OPG in rat mandible model. MAP/Gel supports osseointegration of dental implant after implantation. It is hypothesized that MAP/Gel loaded into nanotube Ti dental implants may be applicable as a potential treatment for bone formation and proper integration of dental implants with alveolar bone. Graphical abstract.

Phelligridin D maintains the function of periodontal ligament cells through autophagy in glucose-induced oxidative stress.

PURPOSE: The objective of this study was to investigate whether phelligridin D could reduce glucose-induced oxidative stress, attenuate the resulting inflammatory response, and restore the function of human periodontal ligament cells (HPDLCs). METHODS: Primary HPDLCs were isolated from healthy human teeth and cultured. To investigate the effect of phelligridin D on glucose-induced oxidative stress, HPDLCs were treated with phelligridin D, various concentrations of glucose, and glucose oxidase. Glucose-induced oxidative stress, inflammatory molecules, osteoblast differentiation, and mineralization of the HPDLCs were measured by hydrogen peroxide (H2O2) generation, cellular viability, alkaline phosphatase (ALP) activity, alizarin red staining, and western blot analyses. RESULTS: Glucose-induced oxidative stress led to increased production of H2O2, with negative impacts on cellular viability, ALP activity, and calcium deposition in HPDLCs. Furthermore, HPDLCs under glucose-induced oxidative stress showed induction of inflammatory molecules (intercellular adhesion molecule-1, vascular cell adhesion protein-1, tumor necrosis factor-alpha, interleukin-1-beta) and disturbances of osteogenic differentiation (bone morphogenetic protein-2, and -7, runt-related transcription factor-2), cementogenesis (cementum protein-1), and autophagy-related molecules (autophagy related 5, light chain 3 I/II, beclin-1). Phelligridin D restored all these molecules and maintained the function of HPDLCs even under glucose-induced oxidative stress. CONCLUSIONS: This study suggests that phelligridin D reduces the inflammation that results from glucose-induced oxidative stress and restores the function of HPDLCs (e.g., osteoblast differentiation) by upregulating autophagy.

Guided bone regeneration with a gelatin layer and adenoviral delivery of c-myb enhances bone healing in rat tibia.

Aim: Bone healing becomes problematic during certain states, such as trauma. This study verifies whether the application of c-myb with gelatin promotes bone healing during bone injuries. Materials & methods: A biodegradable membrane was modified with adenoviral vector c-myb (Ad/c-myb) and gelatin and applied in the bone injury site of rat tibia. Results:c-myb enhanced osteogenic differentiation and mineralization in bone marrow stromal cells after induction with osteogenic media. In vivo examination of rat tibia after application of the biodegradable membrane with Ad/c-myb and a gelatin layer demonstrated increased bone volume, bone mineral density, new bone formation and osteogenic molecules, compared with Ad/LacZ. Conclusion:c-myb has the potential to assist bone healing and may be applicable to the treatment of bone during injury.

Effect of gomisin A on osteoblast differentiation in high glucose-mediated oxidative stress.

BACKGROUND: Gomisin A is a lignan isolated from the hexane of Schisandra chinensis fruit extract with antioxidant properties. Oxidative stress mediated by high glucose is one of the major complications of diabetes mellitus. PURPOSE: This study investigates the role of gomisin A in osteoblast differentiation under high glucose-induced oxidative stress in MC3T3 E1 cells and determines its relationship with heme oxygenase-1 (HO-1) and mitochondrial biogenesis. METHODS: MC3T3 E1 cells were treated by gomisin A following induced by high glucose levels and glucose oxidase to investigate the inhibitory effect of gomisin A against high glucose oxidative stress. Western blot analysis, alizarin red staining, alkaline phosphatase (ALP) activity, analysis of reactive oxygen species (ROS) and confocal microscopy were used to determine mitochondrial biogenesis, oxidative stress, osteoblast differentiation and mineralization. To analyze the role of HO-1, the MC3T3 E1 cells were treated with the HO-1 inhibitor zinc protoporphyrin IX (ZnPP). RESULTS: Gomisin A enhanced the expression of HO-1, increased mitochondrial biogenesis factors (peroxisome proliferator-activated receptor gamma coactivator 1-alpha, nuclear respiratory factor-1, and mitochondrial transcription factor A), antioxidant enzymes (copper-zinc superoxide dismutases and manganese superoxide dismutase), osteoblast differentiation molecules (bone morphogenic protein-2/7, osteoprotegerin and Runt-related transcription factor-2) and mineralization by upregulation of ALP and alizarin red staining, which were decreased by ZnPP and high glucose oxidative stress. Similarly, gomisin A inhibited ROS which was increased by ZnPP and the high glucose-mediated oxidative stress. CONCLUSIONS: The findings demonstrated the antioxidative effects of gomisin A, and its role in mitochondrial biogenesis and osteoblast differentiation. It potentially regulated osteoblast differentiation under high glucose-induced oxidative stress via upregulation of HO-1 and maintenance of mitochondrial homeostasis. Thus, gomisin A may represent a potential therapeutic agent for prevention of bone fragility fractures and implant failure triggered by diabetes.

Schisandra chinensis extract ameliorates age-related muscle wasting and bone loss in ovariectomized rats.

Exercise and healthy diet consumption support healthy aging. Schisandra chinensis (Turcz.) also known as "Baill." has anti-inflammatory and antioxidant properties. However, the role of S. chinensis as an antiaging compound has yet to be demonstrated. This study elucidated the antiaging effect of S. chinensis ethanol-hexane extract (C1) and the effect of C1 treatment on muscle and bone following physical exercise in ovariectomized (OVX) rats. RAW 264.7, human diploid fibroblasts (HDFs), C2C12 myoblasts, bone marrow macrophages, and MC3T3-E1 cells were used for in vitro, and muscle and bone of OVX rats were used for in vivo study to demonstrate the effect of C1. The C1 significantly inhibited the expression of inflammatory molecules, ß-galactosidase activity, and improved antioxidant activity via down-regulation of reactive oxygen species in RAW 264.7 and aged HDF cells. The C1 with exercise improved muscle regeneration in skeletal muscle of OVX rats by promoting mitochondrial biogenesis and autophagy. C1 induced osteoblast differentiation, and C1 + exercise modulated the bone formation and bone resorption in OVX rats. C1 exhibited anti-inflammatory, antioxidant, myogenic, and osteogenic effects. C1 with exercise improved age-related muscle wasting and bone loss. Therefore, S. chinensis may be a potential prevent agent for age-related diseases such as sarcopenia and osteoporosis.

Interval running training improves age-related skeletal muscle wasting and bone loss: Experiments with ovariectomized rats.

NEW FINDINGS: What is the central question of this study? What is the effect and mechanism of interval running training on age-related muscle wasting and bone loss in an ovariectomized rat model? What is the main finding and its importance? Interval running training improved muscle growth and osteogenic differentiation by enhancing the expression of bone morphogenic proteins and sirtuins in ageing-induced ovariectomized rats. Therefore, the repetition of low and high intensities within a single exercise bout, such as interval running training, may be recommended as a practical intervention to prevent skeletal muscle wasting and bone loss in the elderly. ABSTRACT: Effective prophylactic strategies are needed for the suppression of age-related muscle wasting and bone loss after menopause. Exercise training is attractive due to its potential for improving energy metabolism, as well as age-related muscle wasting and bone loss. In particular, interval running (IR) training involves a repetition of low and high intensities within a single exercise bout. Therefore, this study elucidated the effect of interval training on muscle and bone health, as well as anti-ageing, in ovariectomized (OVX) rats. The anti-ageing effect of IR on muscle and bone was tested using western blotting and micro-computed tomography analysis, tartrate-resistant acid phosphatase and immunohistochemical staining. IR significantly inhibited the expression of inflammatory molecules, and improved antioxidant activity via down-regulation of mitogen-activated protein kinases (MAPKs) in the ageing-induced OVX rats skeletal muscle. IR compared with continuous running (CR) improved muscle mass and growth in OVX rats by the promotion of muscle growth-related factors including MyoD, myogenin, phospho-mechanistic target of rapamycin (p-mTOR), sirtuins (SIRTs), and bone morphogenic proteins (BMPs). IR also effectively recovered OVX-induced bone loss via the down-regulation of bone resorption and osteoclast formation in receptor activator of nuclear factor κB ligand (RANKL)-treated bone marrowmacrophages (BMMs). In particular, IR led to high expression of SIRT1 and 6, which promoted osteogenic differentiation and bone formation via modulating the BMP signalling pathway compared with CR training. The in vivo effect of IR was confirmed by immunohistochemical staining with the improvement of bone formation molecules such as BMPs and SIRTs. These results suggested that IR training affected myogenic and osteogenic formation. So, IR training may be considered for prevention of muscle wasting and bone loss for the elderly.

Chitosan-gold nanoparticles mediated gene delivery of c-myb facilitates osseointegration of dental implants in ovariectomized rat.

Osseointegration of dental implants is affected by osteoporosis. The purpose of this study was overcome the implant failure and facilitate the osseointegration of dental implants by c-myb in ovariectomized (OVX)-induced osteoporosis. c-myb is a transcription factor and supports bone formation. Plasmid DNA/c-myb conjugated with chitosan-gold nanoparticles (Ch-GNPs/c-myb) promoted osteogenesis and inhibited osteoclastogenesis in MC-3T3 E1 cells. Ch-GNPs/c-myb involved the reduction of the nuclear factor of activated T-cells 1, c-Fos, and tartrate-resistant acid phosphatase-positive multinucleated osteoclasts in receptor activator of nuclear factor-κB ligand (RANKL) stimulated bone marrow macrophages. In vivo results of rat mandibles demonstrated Ch-GNP/c-myb-coated titanium (Ti) implants increased the volume and density of newly formed bone and the osseointegration of dental implant with bone by micro computed tomography examination after OVX-induced osteoporosis. Immunohistochemical analysis showed increased c-myb expression and upregulation of bone morphogenic proteins, osteoprotegerin and EphB4, as well as the downregulation of RANKL by Ch-GNP/c-myb-coated Ti implants. Hematoxylin and Eosin staining expressed new bone formation by Ch-GNP/c-myb-coated Ti implants. Our findings indicated that c-myb delivered by Ch-GNPs supports osseointegration of dental implant even in osteoporotic condition. c-myb may be applicable to support dental implant integration and treatment in age-dependent bone destruction disease.

Phelligridin D-loaded oral nanotube titanium implant enhances osseointegration and prevents osteolysis in rat mandible.

Poor bone quality and osteolysis are the major causes of implant failure in dentistry. Here, this study tested the effect of phelligridin D-loaded nanotubes titanium (Ti) for bone formation around the dental implants. The purpose of this study was to enhance osseointegration of phelligridin D-loaded implant into the bone for bone formation and prevention of osteolysis. Cell viability, crystal violet staining, Western blot, alizarin red S staining, alkaline phosphatase activity, tartrate-resistant acid phosphatase staining, micro-computed tromography (µ-CT), hematoxylin and eosin (H&E) and immunohistochemical staining were used in vitro and in vivo to test the biocompatibility of phelligridin D. Phelligridin D enhanced osteoblast differentiation and mineralization by increasing bone morphogenic protein-2/7 (BMP-2/7), Osterix, Runx-2, osteoprotegerin (OPG), alkaline phosphatase and inhibited osteoclast differentiation by decreasing receptor activator of nuclear factor kappa-B ligand (RANKL) in MC-3T3 E1 cells. Further, phelligridin D promoted bone regeneration around nanotube Ti implant surface by increasing the levels of BMP-2/7 and OPG in a rat model. Phelligridin D also inhibited osteolysis by suppressing the expression of RANKL. These findings strongly suggest that phelligridin D is a new compound representing a potential therapeutic candidate for implant failure caused by osteolysis and poor bone quality of teeth.

Schisandrin C enhances odontoblastic differentiation through autophagy and mitochondrial biogenesis in human dental pulp cells.

OBJECTIVE: To investigate the role of Schisandrin C in odontoblastic differentiation, and its relations between autophagy and mitochondrial biogenesis in human dental pulp cells (HPDCs). DESIGN: Fresh third molars were used, and cultured for HDPCs. Western blotting technique, Alizarin red S staining, alkaline phosphatase (ALP) activity, and confocal microscopy were used to detect autophagy, mitochondrial biogenesis, and odontoblastic differentiation. To understand the mechanism of Schisandrin C, the HDPCs were treated with lipopolysaccharide (LPS), autophagy and heme oxygenase-1 (HO-1) inhibitors: 3-Methyladenine (3-MA) and Zinc protoporphyrin IX (ZnPP), respectively. RESULTS: LPS decreased the expression of autophagy molecules [autophagy protein 5 (ATG-5), beclin-1, and microtubule-associated protein 1A/1B light chain 3 (LC3-I/II)] and mitochondrial biogenesis molecules [heme oxygenase-1 (HO-1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)], and disrupted odontoblastic differentiation. The down-regulation of autophagy and mitochondrial biogenesis with 3-MA and ZnPP inhibited odontoblastic differentiation. However, Schisandrin C restored the expression of all the above molecules, even with LPS and inhibitor treatment. This result demonstrates that autophagy and mitochondrial biogenesis plays an essential role in odontoblastic differentiation, and Schisandrin C activates these systems to promote odontoblastic differentiation of HDPCs. CONCLUSION: Schisandrin C has potential characters to regulate odontoblastic differentiation, and may be recommended for use as a compound for pulp homeostasis.

Enhancing of Osseointegration with Propolis-Loaded TiO2 Nanotubes in Rat Mandible for Dental Implants.

TiO2 nanotubes (TNT) formation is beneficial for improving bone cell-material interaction and drug delivery for Ti dental implants. Among the natural drugs to be installed in TNT, selected propolis has antibacterial and anti-inflammatory properties. It is a resinous natural product which is collected by the honeybees from the various types of plants with their salivary enzymes. This study concludes that TNT loaded with a propolis (PL-TNT-Ti) dental implant has the ability to improve osseointegration. The propolis particles were embedded within the TNT or adhered to the top. In a cytotoxicity test using osteoblast, PL-TNT-Ti group exhibited an increased cell proliferation and differentiation. A Sprague Dawley rat mandibular model was used to evaluate the osseointegration and bone bonding of TNT or PL-TNT-Ti. From the µ-CT and hematoxylin and eosin (HE) histological results after implantation at 1 and 4 weeks to rat mandibular, an increase in the extent of new bone formation and mineral density around the PL-TNT-Ti implant was confirmed. The Masson's trichrome staining showed the expression of well-formed collagenous for bone formation on the PL-TNT-Ti. Immunohistochemistry staining indicate that bone morphogenetic proteins (BMP-2 and BMP-7) around the PL-TNT-Ti increased the expression of collagen fibers and of osteogenic differentiation whereas the expression of inflammatory cytokine such as interleukin-1 beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) is decreased.

Spliceosome-Associated Protein 130 Exacerbates Alcohol-Induced Liver Injury by Inducing NLRP3 Inflammasome-Mediated IL-1ß in Mice.

Excessive alcohol consumption leads to chronic liver diseases. Macrophage-inducible C-type lectin (Mincle) is a C-type lectin receptor that recognizes spliceosome-associated protein 130 (SAP130) known as an endogenous ligand released from dying cells. The aim was to examine the role of Mincle-SAP130 in the pathogenesis of alcoholic liver disease. Alcohol-induced liver injury was induced in wild-type (WT) and Mincle knockout (KO) mice by using a chronic-binge ethanol-feeding model. Mincle KO mice showed significant lower hepatic steatosis, inflammation with neutrophil infiltration, and fibrosis compared with WT mice after alcohol feeding. In contrast, Mincle activation exacerbated alcohol-induced liver injury. Kupffer cells (KCs) are major sources of Mincle. IL-1ß expression was significantly down-regulated in Mincle KO mice compared with that in WT mice after alcohol consumption. Interestingly, expression and production of IL-1ß were significantly decreased in SAP130-treated KCs isolated from leucine-rich-containing family pyrin domain containing-3-deficient mice compared with those in WT KCs. Such results were also observed in cells treated with SAP130 plus Syk inhibitor. Furthermore, infiltration of invariant natural killer T cells was decreased in livers of Mincle KO mice. Finally, inhibition of Syk signaling ameliorated alcohol-induced liver injury. Collectively, these results demonstrated that interaction between Mincle and SAP130 may promote the progression of alcoholic liver disease by IL-1ß production in KCs and consequently increase inflammatory immune cell infiltration.

Gomisin A modulates aging progress via mitochondrial biogenesis in human diploid fibroblast cells.

Gomisin A from the fruit of Schisandra chinensis has many pharmacological properties, including hepato-protective, anti-diabetic, and anti-oxidative stress. However, the potential benefit of gomisin A is still not well understood, especially in aging progression. Therefore, the aim of this study was to clarify whether the promotion of mitochondrial biogenesis and autophagy of gomisin A affects anti-aging progression, and its mechanism. Intermediate (PD32) human diploid fibroblast (HDF) cells were brought to stress-induced premature senescence (SIPS) using hydrogen peroxide. Gomisin A inhibited reactive oxygen species production even in the SIPS-HDF cells. Gomisin A was also able to attenuate the activity of senescence-associated ß-galactosidase and the production of pro-inflammatory molecules in the SIPS as well as aged HDF cells. The antioxidant activity of gomisin A was determined by recovering the Cu/Zn, Mn-SOD, and HO-1 expression in the SIPS-HDF cells. In mechanistic aspect, gomisin A inhibited the mitogen-activated protein kinase pathway and the translocation of nuclear factor kappa B to the nucleus. In addition, gomisin A promoted the autophagy and mitochondrial biogenesis factors through the translocation of nuclear factor erythroid 2-related factor-2, and inhibited aging progression in the SIPS-HDF cells. In summary, the enhanced properties of mitochondrial biogenesis and autophagy of gomisin A has a benefit to control age-related molecules against SIPS-induced chronic oxidative stress, and gomisin A may be a potential therapeutic compound for the enhancement of intracellular homeostasis to aging progression.

Schisandrin C enhances mitochondrial biogenesis and autophagy in C2C12 skeletal muscle cells: potential involvement of anti-oxidative mechanisms.

The molecular study of muscles is needed to overcome chronic inflammation and maintenance of muscles in the human body. Schisandrin C is a pharmacological compound derived from the fruit of Schisandra chinensis and has many characteristics including anti-inflammation, anti-tumor, and anti-oxidation. However, the cellular and molecular mechanisms of Schisandrin C are still not well understood especially in skeletal muscle. Therefore, the present study was evaluated whether the properties of Schisandrin C in C2C12 skeletal muscle cells involved maintenance of cellular homeostasis and protection against oxidative damage. Differentiated C2C12 cells were exposed to H2O2 to induce oxidative stress. The characteristics of anti-oxidants, anti-inflammation, autophagy, and mitochondrial biogenesis were tested by Western blotting. Confocal microscopy was also used to observe mitochondrial activity. Schisandrin C inhibited inflammatory molecules with enhancing anti-oxidant activity and reducing reactive oxygen species (ROS) even in the presence of H2O2. The dual anti-inflammation and anti-oxidant roles of Schisandrin C regulated the translocation of nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor-2 (Nrf-2) to nucleus followed by inhibition of the mitogen-activated protein kinase (MAPK) pathway. Schisandrin C promoted the expression of autophagy and mitochondrial biogenesis molecules. Furthermore, the effect of Schisandrin C increased the mitochondrial activity against oxidative stress. Consequently, the action of Schisandrin C enhanced the regulation of autophagy and mitochondrial biogenesis with potential involvement of anti-oxidative mechanisms including the MAPKs/Nrf-2/heme oxygenase-1 signaling pathway in C2C12 skeletal muscle cells exposed to oxidative stress. Therefore, Schisandrin C may be considered as a beneficial compound for several muscle inflammations.

Effect of Ca-P compound formed by hydrothermal treatment on biodegradation and biocompatibility of Mg-3Al-1Zn-1.5Ca alloy; in vitro and in vivo evaluation.

Chemical combinations of Ca-P produced via plasma electrolytic oxidation (PEO) and a hydrothermal treatment were fabricated to improve the initial corrosion resistance and biocompatibility of a biodegradable Mg-3Al-1Zn-1.5Ca alloy. For the formation of an amorphous calcium phosphate composite layer on the surface of a magnesium alloy, a PEO layer composed of MgO and Mg3(PO4)2 was formed by PEO in electrolytes containing preliminary phosphate ions. During the second stage, a thick and dense Ca layer was formed by Ca electrodeposition after PEO. Finally, a hydrothermal treatment was carried out for chemical incorporation of P ions in the PEO layer and Ca ions in the electrodeposition layer. The amorphous calcium phosphate composite layer formed by the hydrothermal treatment enhanced osteoblast activity and reduced H2O2 production, which is a known stress indicator for cells. As a result of co-culturing osteoblast cells and RAW 264.7 cells, the formation of amorphous calcium phosphate increased osteoblast cell differentiation and decreased osteoclast cell differentiation. Implanting the alloy, which had an amorphous calcium phosphate composite layer that had been added through hydrothermal treatment, in the tibia of rats led to a reduction in initial biodegradation and promoted new bone formation.

Nanoparticle mediated PPARγ gene delivery on dental implants improves osseointegration via mitochondrial biogenesis in diabetes mellitus rat model.

Diabetes mellitus (DM) has a detrimental effect on osseointegration, stability and longevity of implants due to osteoporosis. In this study, PPARγ-loaded dental implants were investigated for the improvement of osseointegration and peri-implantitis. Chitosan gold nanoparticles conjugated with PPARγ cDNA were introduced on titanium mini-implant surfaces for PPARγ release to rat mandibular. DM-induced rat mandible showed structural changes such as decreased bone mass and increased inflammatory molecules, and diminution of PPARγ expression and bone formation molecules compared to normal rats. PPARγ induced bone formation via reduction of inflammatory molecules even under glucose oxidative stress. Furthermore, PPARγ strongly activated mitochondrial biogenesis and cell viability via p-AMK and Wnt/ß-catenin signaling. Consequently, PPARγ gene delivery on regional dental implants contributed osseointegration, new bone formation and mineralization in DM-induced rats. This study demonstrates that PPARγ can be used as a therapeutic gene with dental implantation in diabetic patients since regional PPARγ expression enhances osseointegration and implant longevity.

PPARγ regulates inflammatory reaction by inhibiting the MAPK/NF-κB pathway in C2C12 skeletal muscle cells

Excessive exercise induces an inflammatory response caused by oxidative stress, which delays recovery of damaged muscle fibers. The reduction of inflammatory response is important for skeletal muscle homeostasis. Peroxisome proliferator-activated receptor gamma (PPARγ) is an anti-inflammatory molecule, but the role of PPARγ in skeletal muscle as anti-inflammatory activity is not clear. Thus, this study examined the anti-inflammatory role of PPARγ against H2O2-induced oxidative stress in skeletal muscle. Sprague Dawley (SD) rats were exercised on a treadmill to induce oxidative stress. In vitro oxidative stress was evaluated in differentiated C2C12 cells stimulated using 200 μM H2O2. Inflammation-related molecules were determined by immunohistochemistry and Western blot analysis. Expressions of the inflammatory molecules tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), cyclooxygenase-2 (COX-2), and matrix metalloproteinase-2 (MMP-2) in muscles of the acute exercise group were highly increased. PPARγ was also highly expressed in these muscles. These inflammatory molecules were also markedly increased in C2C12 cells with H2O2 stimulation. However, PPARγ overexpression in C2C12 transfected by Ad/PPARγ dramatically reduced the inflammatory molecules. PPARγ also enhanced the anti-oxidants molecules like Cu/Zn-SOD, Mn-SOD, and hemeoxygenase-1 by reducing the generation of ROS, even in the presence of H2O2. PPARγ displayed dual anti-inflammatory and anti-oxidant roles by inhibiting the mitogen-activated protein kinase (MAPK) pathway and translocation of nuclear transcriptional factor-κB (NF-κB) from the cytosol to the nucleus. These results demonstrate a potential role of PPARγ in protecting muscle fibers against oxidative stress caused by excessive acute exercise due to its anti-inflammatory and anti-oxidant activity exerted by inhibition of the MAPK/NF-κB pathway (AU)

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Existence of ATP sensitive potassium currents on human periodontal ligament cells.

OBJECTIVE: Potassium channels of the ATP-sensitive family (KATP channel) are inhibited by increase in intracellular ATP. Electrophysiological studies have demonstrated that the kinetics and pharmacological properties of KATP channels vary among different tissues, suggesting structurally and functionally distinct types. There are studies showing human periodontal ligament (PDL) cells respond to mechanical stress by increasing ATP release, which participates in bone resorption or bone homeostasis. So, in this study we investigated the existence of KATP channel subunit and their single channel properties in human periodontal ligaments. MATERIALS & METHOD: The human PDL cells were isolated from healthy erupted third molar. For patch-clamp experiments, human PDL fibroblasts were seeded on 3.5cm plastic dishes. The inside-out patch clamp recordings were performed under voltage clamp mode. Reverse transcriptase polymerase chain reaction (RT-PCR) was conducted to identify the channel subunits. All pair-wise comparisons were performed by Paired t-test. A P value <0.05 was considered significant. RESULTS: We observed mRNA transcripts for Kir6.1, Kir6.2 and Sur2B subuits in the human PDL cells. In inside-out patch mode, the single channel conductance was 163pS at symmetrical K+ concentration of 140mM and inward rectification was seen in ATP-free bath solution. The reversal potential of the currents was found to be 0mV at symmetrical concentration (140mM) of K+ in bath solution. The single channel currents were almost blocked by adding 5mM ATP in the bath solution. However, the currents were not blocked by 100µM glibenclamide, a subunit specific KATP channel blocker. CONCLUSIONS: These results indicate that human PDL cells express KATP channels subunit including Sur2B and Kir6.1 and Kir6.2 which are sensitive to ATP but insensitive to glibenclamide.