Liehu Cao

Glial cell line-derived neurotrophic factor promotes survival and induces differentiation through the phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathway respectively in PC12 cells.

PC12-GFRalpha1 cells, a clonal cell line engineered to express glial cell line-derived neurotrophic factor receptor alpha1 were constructed. Given glial cell line-derived neurotrophic factor could induce the differentiation and promote the survival of PC12-GFRalpha1 cells at low concentrations, the cells provide an unlimited source of monoclonal cells for studies on the signal transduction pathway of glial cell line-derived neurotrophic factor. To characterize the involvement of the mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways in the biological effect of glial cell line-derived neurotrophic factor, we used the mitogen-activated protein kinase kinase inhibitor PD98059 and the phosphatidylinositol 3-kinase inhibitor LY294002. PD98059 blocked glial cell line-derived neurotrophic factor-induced PC12-GFRalpha1 cells neurite formation in a dose-dependent manner, without significantly altering cell viability. LY294002 reversed the survival-promoting effect of glial cell line-derived neurotrophic factor on the PC12-GFRalpha1 cells in serum-deprived medium. The present study demonstrates that phosphatidylinositol 3-kinase pathway seems to mediate the survival-promoting effect of glial cell line-derived neurotrophic factor on PC12-GFRalpha1 cells, while the activation of mitogen-activated protein kinase pathway could be an important step in mediating PC12-GFRalpha1 cells differentiation induced by glial cell line-derived neurotrophic factor. Therefore, it is inferred that similar intracellular signaling components are used by distinct growth factors toward a common biological effect.

Surgical Treatment of Calcaneal Fractures of Sanders Type II and III by a Minimally Invasive Technique Using a Locking Plate

The aim of the present study was to investigate the outcomes of surgical treatment of calcaneal fractures of Sanders type II and III using a minimally invasive technique and a locking plate. We reviewed 33 feet in 33 consecutive patients with Sanders type II and III calcaneal fractures who had undergone a minimally invasive technique using percutaneous reduction and locking plates. All operations were performed by the same surgeons. The postoperative evaluation included radiographs, determination of restoration of Böhlers angle and Gissanes angle, and administration of the American Orthopaedic Foot and Ankle Society ankle-hind foot scale, Maryland Foot Score, and visual analog scale of pain. The mean visual analog scale score was 1.6 ± 1.4 when radiographic fracture healing was observed. The median functional score of the 33 patients (33 feet) reached 82 (interquartile range 80 to 99) at the last follow-up evaluation according to the American Orthopaedic Foot and Ankle Society ankle-hind foot scale and 89 (interquartile range 80 to 99) according to Maryland Foot Score. All cases achieved restoration of a normal Böhlers angle and Gissanes angle. Postoperative superficial infections occurred in 2 patients, subtalar arthritis developed in 2, and no soft tissue necrosis was observed. For Sanders type II and III fractures of the calcaneus bone, treatment with a minimally invasive technique combining percutaneous reduction and locking plate fixation provided satisfactory clinical results, with a lower incidence of complications. However, longer term studies with a larger sample size and more randomized controlled trials are required to define the superiority of our minimally invasive technique compared with conventional surgical treatment of calcaneal fractures.

Matrine prevents bone loss in ovariectomized mice by inhibiting RANKL-induced osteoclastogenesis

Osteoporosis is a metabolic bone disease characterized by decreased bone density and strength due to excessive loss of bone protein and mineral content. The imbalance between osteogenesis by osteoblasts and osteoclastogenesis by osteoclasts contributes to the pathogenesis of postmenopausal osteoporosis. Estrogen withdrawal leads to increased levels of proinflammatory cytokines. Overactivated osteoclasts by inflammation play a vital role in the imbalance. Matrine is an alkaloid found in plants from the Sophora genus with various pharmacological effects, including anti‐inflammatory activity. Here we demonstrate that matrine significantly prevented ovariectomy‐induced bone loss and inhibited osteoclastogenesis in vivo with decreased serum levels of TRAcp5b, TNF‐α, and IL‐6. In vitro matrine significantly inhibited osteoclast differentiation induced by receptor activator for NF‐κB ligand (RANKL) and M‐CSF in bone marrow monocytes and RAW264.7 cells as demonstrated by tartrate‐resistant acid phosphatase (TRAP) staining and actin‐ring formation as well as bone resorption through pit formation assays. For molecular mechanisms, matrine abrogated RANKL‐induced activation of NF‐κB, AKT, and MAPK pathways and suppressed osteoclastogenesis‐related marker expression, including matrix metalloproteinase 9, NFATc1, TRAP, C‐Src, and cathepsin K. Our study demonstrates that matrine inhibits osteoclastogenesis through modulation of multiple pathways and that matrine is a promising agent in the treatment of osteoclast‐related diseases such as osteoporosis.—Chen, X., Zhi, X., Pan, P., Cui, J., Cao, L., Weng, W., Zhou, Q., Wang, L., Zhai, X. Zhao, Q., Hu, H., Huang, B., Su, J. Matrine prevents bone loss in ovariectomized mice by inhibiting RANKL‐induced osteoclastogenesis. FASEB J. 31, 4855–4865 (2017). www.fasebj.org

Inhalation of water electrolysis-derived hydrogen ameliorates cerebral ischemia-reperfusion injury in rats - A possible new hydrogen resource for clinical use.

Hydrogen is a kind of noble gas with the character to selectively neutralize reactive oxygen species. Former researches proved that low-concentration of hydrogen can be used to ameliorating cerebral ischemia/reperfusion injury. Hydrogen electrolyzed from water has a hydrogen concentration of 66.7%, which is much higher than that used in previous studies. And water electrolysis is a potential new hydrogen resource for regular clinical use. This study was designed and carried out for the determination of safety and neuroprotective effects of water electrolysis-derived hydrogen. Sprague-Dawley rats were used as experimental animals, and middle cerebral artery occlusion was used to make cerebral ischemia/reperfusion model. Pathologically, tissues from rats in hydrogen inhalation group showed no significant difference compared with the control group in HE staining pictures. The blood biochemical findings matched the HE staining result. TTC, Nissl, and TUNEL staining showed the significant improvement of infarction volume, neuron morphology, and neuron apoptosis in rat with hydrogen treatment. Biochemically, hydrogen inhalation decreased brain caspase-3, 3-nitrotyrosine and 8-hydroxy-2-deoxyguanosine-positive cells and inflammation factors concentration. Water electrolysis-derived hydrogen inhalation had neuroprotective effects on cerebral ischemia/reperfusion injury in rats with the effect of suppressing oxidative stress and inflammation, and it is a possible new hydrogen resource to electrolyze water at the bedside clinically.

Influences of doping mesoporous magnesium silicate on water absorption, drug release, degradability, apatite-mineralization and primary cells responses to calcium sulfate based bone cements

In this study, composite cements containing mesoporous magnesium silicate (m-MS) and calcium sulfate (CS) were fabricated. The results revealed that the setting time of the m-MS/CS composite cements (m-MSC) slightly prolonged with the increase of m-MS content while the compressive strength suffered a little loss. The doping of m-MS improved the water absorption, drug release (vancomycin) and degradability of the m-MSC in Tris-HCl solution (pH=7.4). In addition, addition of m-MS facilitated the apatite-mineralization of m-MSC in simulated body fluid (SBF), indicating good bioactivity. For cell cultural experiments, the results revealed that the m-MSC promoted the cells adhesion and proliferation, and improved the alkaline phosphatase (ALP) activity of MC3T3-E1 cells, revealing good cytocompatibility. It could be suggested that the m-MSC might be promising cements biomaterials for bone tissue regeneration.

Controlled release of vancomycin from 3D porous graphene-based composites for dual-purpose treatment of infected bone defects

Infected bone defects (IBD) are a challenging problem in orthopedic practice. Biomaterials have attracted attention as a novel approach to overcome this challenge instead of using conventional strategies. Graphene, a two-dimensional carbon allotrope, has been shown to possess multiple advantages, such as osteogenesis-promoting activity, a large surface area for drug delivery, and antibacterial activities. However, these attractive merits have not been entirely explored or introduced for the management of IBD. Herein, a novel approach using a vancomycin-laden, self-assembled, graphene-based material against IBD was developed, and the approach uses a single-stage bone graft instead of multiple procedures. Owing to the π–π bonding with graphene, vancomycin can be promptly delivered in the initial stage, followed by a sustained release, which ensures the rapid elimination of an infection and provides a durable pathogen revival inhibition via the inherent antibacterial activity of graphene. Moreover, the 3D porous structure incorporated with nano-hydroxyapatite (nHA) provided a biomimetic microenvironment favored by cell adhesion and osteogenic differentiation. Further evaluation of this system in an IBD animal model demonstrated prompt control of infection and promotion of bone regeneration. These results revealed the potential of this approach to be an effectual solution for IBD treatment and a new area of graphene application in the future.

Matrine derivate MASM uncovers a novel function for ribosomal protein S5 in osteoclastogenesis and postmenopausal osteoporosis

Postmenopausal osteoporosis (POMP) is a public health problem characterized by decreased bone density and increased fracture risk. Over-activated osteoclastogenesis plays a vital role in POMP. Here we developed a novel bioactive compound MASM (M19) based on sophocarpine. Although it showed no significant effects on osteogenesis and adipogenesis for bone marrow-derived mesenchymal stem cells (BMSCs) in vitro, it could significantly inhibit RANKL/M-CSF induced osteoclastogenesis through suppressing NF-κB, MAPKs and PI3K/Akt pathways in vitro and ameliorate bone loss in ovariectomized mice in vivo. Ribosomal protein s5 (RPS5) has been identified as a target of M19 and regulates PI3K/Akt, NF-κB and MAPKs pathways in osteoclastogenesis. Overexpressions of RPS5 synergistically inhibited osteoclastogenesis with M19 while silencing RPS5 compromised M19 inhibitory effects on osteoclastogenesis in vitro. Among the three pathways, Akt plays a major role in M19 effects. The Akt activator SC79 partially reversed the inhibitory effects on osteoclastogenesis by M19 and RPS5-knocking-down. It indicates that RPS5 serves as a potential candidate target for inhibiting osteoclastogenesis and osteoporosis therapy and M19 is a promising agent for POMP treatment.

Effects of mesoporous calcium magnesium silicate on setting time, compressive strength, apatite formation, degradability and cell behavior to magnesium phosphate based bone cements

Mesoporous calcium magnesium silicate was doped into magnesium phosphate to fabricate magnesium phosphate based composite cements (MBC). The results showed that the setting time was significantly prolonged from 4 min to 11 min while the compressive strength decreased from 17 MPa to 9 MPa. In addition, the apatite formation ability improved in simulated body fluid (SBF) and degradation of the composite cements in Tris–HCl solution increased with the increase of m-CMS content of the MBC. Importantly, the MBC with excellent cytocompatibility remarkably promoted the MC3T3-E1 cells proliferation and differentiation, which depended on the m-CMS content. It can be suggested that MBC with good bioactivity, degradability and cytocompatibility has great potential to serve as implanted cements for bone defect filler and repairs.

Promotion of in vivo degradability, vascularization and osteogenesis of calcium sulfate-based bone cements containing nanoporous lithium doping magnesium silicate

Nanoporous lithium doping magnesium silicate (nl-MS) was introduced into calcium sulfate hemihydrate to prepare calcium sulfate composite (nl-MSC) bone cements. The introduction of nl-MS improved the in vitro degradability of nl-MSC cements, which could neutralize acidic degradable products of calcium sulfate and prevented the pH from dropping. The cements were implanted into the bone defects of femur bone of rabbits, and the results of histological and immunohistochemical analysis revealed that massive new bone tissue formed in the defects while the cements were degradable, indicating that the osteogenesis and degradability of the nl-MSC cements were much better than the control calcium sulfate dihydrate (CSD) cements. Furthermore, the positive expression of vascular endothelial growth factor and collagen type I for nl-MSC cements was higher than CSD, indicating that addition of nl-MS into the cements enhanced vascularization and osteogenic differentiation. The results suggested that the nl-MSC cements with good biocompatibility and degradability could promote vascularization and osteogenesis, and had great potential to treat bone defects.

Influences of mesoporous magnesium calcium silicate on mineralization, degradability, cell responses, curcumin release from macro-mesoporous scaffolds of gliadin based biocomposites

Macro-mesoporous scaffolds based on wheat gliadin (WG)/mesoporous magnesium calcium silicate (m-MCS) biocomposites (WMC) were developed for bone tissue regeneration. The increasing amount of m-MCS significantly improved the mesoporosity and water absorption of WMC scaffolds while slightly decreased their compressive strength. With the increase of m-MCS content, the degradability of WMC scaffolds was obviously enhanced, and the decrease of pH value could be slow down after soaking in Tris-HCl solution for different time. Moreover, the apatite mineralization ability of the WMC scaffolds in simulated body fluid (SBF) was obviously improved with the increase of m-MCS content, indicating good bioactivity. The macro-mesoporous WMC scaffolds containing m-MCS significantly stimulated attachment, proliferation and differentiation of MC3T3-E1 cells, indicating cytocompatibility. The WMC scaffold containing 40 w% m-MCS (WMC40) possessed the highest porosity (including macroporosity and mesoporosity), which loaded the highest amount of curcumin (CU) as well as displayed the slow release of CU. The results suggested that the incorporation of m-MCS into WG produced biocomposite scaffolds with macro-mesoporosity, which significantly improved water absorption, degradability, bioactivity, cells responses and load/sustained release of curcumin.