IL-1beta induces and TGF-beta reduces vitamin D3-induced bone resorption in mouse calvarial bone cells

Transforming Growth Factor β1 (TGF-β1) in the Sera of Postmenopausal Osteoporotic Females

BACKGROUND

Postmenopausal osteoporosis is a major cause of morbidity in postmenopausal females. Transforming growth factor β1 (TGF-β1) and interleukin 18 (IL-18) play complex roles in normal bone metabolism, and in pathophysiology of postmenopausal osteoporosis.

OBJECTIVES

The aim of this study was to design an analytic cross sectional study in order to further clarify the role of TGF-β1 and IL-18 in osteoporosis of postmenopausal females.

METHODS

A cross sectional study including 65 postmenopausal osteoporotic females as cases and 69 postmenopausal females of similar age without osteoporosis as controls was conducted. Dual energy X-ray absorptiometry (DXA) was used to determine bone mass density (BMD) of participants and T-scoring was applied to establish whether the patient has osteoporosis or not. Serum TGF-β1 and IL-18 levels were measured by quantitative sandwich Enzyme linked immunosorbent assay (ELISA).

RESULTS

Serum TGF-β1 levels were significantly higher in osteoporotic postmenopausal females than non-osteoporotic individuals (23.8 vs. 15.8 ng/mL; P = 0.009). There was no difference between IL-18 levels in the sera of osteoporotic and non-osteoporotic postmenopausal females in this study. There was a positive correlation between body mass index (BMI) and serum level of TGF-β1 (P = 0.04).

CONCLUSIONS

Our study demonstrated that TGF-β1 serum levels is higher in osteoporotic postmenopausal females than non-osteoporotic ones, and probably aberrant increase in TGF-β1 in postmenopausal females can result in uncoupled bone resorption and formation, which leads to osteoporosis.

Proliferation and differentiation of osteoblasts from the mandible of osteoporotic rats

The objective of this study was to identify the differences between osteoblasts derived from normal adult rat mandibles and osteoporotic adult rats. An osteoporotic animal model was established by performing a bilateral ovariectomy (ovx group). The proliferation and differentiation abilities of osteoblasts were determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-2H-tetrazolium bromide), alkaline phosphatase (ALP) and osteocalcin release (OC) assays. Transmission electron microscopy (TEM) was performed to assess differences in the ultrastructure. Proliferating cell nuclear antigen (PCNA) and uncoupling protein 2 (UCP2) protein concentrations were analyzed by Western blot. In addition, UCP2 protein in osteoblasts was assessed by immunohistochemistry staining. ATP and reactive oxygen species (ROS) concentrations were analyzed separately with ATP and ROS quantification kits. At four and 12 weeks after the operation, osteoblasts of the ovx group showed earlier attachment, fewer dead cells and faster growth compared with cells in the sham group. TEM showed that osteoblasts of the ovx group had fewer folds, lysosomes, peroxisomes and less rough endoplasmic reticulum. The results of the MTT, ALP activity and OC assays were all higher in osteoblasts from the ovx group at four or 12 weeks postsurgery than osteoblasts from the sham group. PCNA protein concentrations in the ovx group increased significantly compared with those of the sham group at four or 12 weeks after the operation, but UCP2 concentrations decreased over the same time period. UCP2 immunohistochemical staining of osteoblasts showed that the protein was concentrated in the cytoplasm and that the osteoblasts from the sham group had higher expression than those from the ovx group. The ATP and ROS concentrations of the ovx groups were significantly higher than the sham groups at four or 12 weeks postsurgery. Therefore, we concluded that there are differences in cell ultrastructure, proliferation, differentiation, ATP and ROS concentrations, and PCNA and UCP2 protein expression levels in osteoblasts from the mandibles of rats of the ovx group compared with those from the sham group.

Vitamin E reversed nicotine-induced toxic effects on bone biochemical markers in male rats

INTRODUCTION

Vitamin E is beneficial in restoring bone histomorphometric parameters in nicotine-treated rats. This study determined the effectiveness of 3 forms of vitamin E in restoring bone metabolism in nicotine-treated rats.

MATERIAL AND METHODS

Thirty-five male Sprague-Dawley rats were divided into 5 groups: (1) control (C), (2) nicotine cessation (NC), (3) α-tocopherol (ATF), (4) tocotrienol-enhanced fraction (TEF) and (5) γ-tocotrienol (GTT). Treatment was carried out for 4 months. The control group was administered normal saline and olive oil throughout the treatment period while treatment for groups 2-5 was performed in 2 phases. In the first phase, the groups received nicotine 7 mg/kg intraperitoneally for 2 months. The following 2 months, group 2 received normal saline and olive oil while groups 3-5 received ATF, TEF or GTT, 60 mg/kg orally. Pre-treatment and post-treatment serum was collected for bone biochemical marker measurement using the ELISA method.

RESULTS

Nicotine increased serum bone-resorbing cytokines (interleukin-1 and interleukin-6) and the bone resorption marker pyridinoline (PYD) while reducing the bone formation marker osteocalcin after 2 months of nicotine treatment. The parameters failed to improve after nicotine was stopped for 2 months. Supplementation with the 3 forms of vitamin E improved the parameters, i.e. reduced the cytokines and pyridinoline as well as increased the osteocalcin. In addition, the TEF and GTT groups had a higher level of osteocalcin than the control group.

CONCLUSIONS

Nicotine impaired bone metabolism and cessation of nicotine treatment did not reverse the effects. Vitamin E, especially the tocotrienols, restored bone metabolism that was impaired due to nicotine.

Effect of safflower seeds supplementation on stimulation of the proliferation, differentiation and mineralization of osteoblastic MC3T3-E1 cells

Anti-bone resorption properties of the Korean herbal formulation, Gami-Honghwain (HJ), which comprises Carthamus tinctorius L. seed and hominis placenta, were investigated. We demonstrate that the production of PGE2 is inhibited by 20-100 microg/ml HJ in nontransformed osteoblastic cells (MC3T3-E1 cells), indicating that HJ inhibits PGE2 production. The effect of HJ on the proliferation and osteoblastic differentiation in MC3T3-E1 was also studied. HJ dose-dependently increased DNA synthesis (significant at 20-100 microg/ml), and increased alkaline phosphatase (ALP) and prolyl hydroxylase activities of MC3T3-E1 cells (20-100 microg/ml), while anti-estrogen tamoxifen eliminated the stimulation of proliferation and ALP activity of MC3T3-E1 which was induced by HJ. These results indicate that HJ directly stimulates cell proliferation and differentiation of osteoblasts. Also, when we assessed the effects of HJ on osteoblastic differentiation in MC3T3-E1, HJ enhanced ALP activity and mineralization in a dose- and time-dependent fashion. This stimulatory effect of the HJ was observed at relatively low doses (significant at 20-100 microg/ml and maximal at 100 microg/ml). Northern blot analysis showed that the HJ (60 microg/ml) increased in bone morphogenetic protein-2 as well as ALP mRNA concentrations in MC3T3-E1 cells. HJ (100 microg/ml) slightly increased in type I collagen mRNA abundance throughout the culture period, whereas it markedly inhibited the gene expression of collagenase-1 between days 15 and 20 of culture. These results indicate that HJ has anabolic effect on bone through the promotion of osteoblastic differentiation, suggesting that it could be used for the treatment of common metabolic bone diseases.

Effects and mechanisms of Clematis mandshurica Maxim. as a dual inhibitor of proinflammatory cytokines on adjuvant arthritis in rats

Effect and mechanism of Clematis mandshurica Maxim. water extract (CMA), a dual inhibitor of interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α), on rat adjuvant arthritis (AA) were investigated. Complete Freund's adjuvant (CFA) was used to induce AA in rats. The extents of inflammation and treatment response were evaluated with regard to lymphocyte proliferation. Serial evaluation was carried out on days 1, 7, 14, 21 and 28 after creation of inflammation. The lymphocyte proliferation study revealed cellular immunosuppression during the early phase of the disease. Administration of CMA on the same day or 5 days prior to inflammatory insult into the joint significantly reduced the inflammation as compared to the untreated animals in a dose dependent manner. The administration of CMA (2, 5 and 10mg/kg, subcutaneously (s.c.)) inhibited the inflammatory response and restored the weight of body and immune organs of AA rats. Synoviocytes proliferation of AA rats significantly increased, and the levels of TNF-α and IL-1 in supernatants of synoviocytes in AA rats were also elevated compared with the nonimmunized rats group. The administration of CMA (2, 5 and 10mg/kg, s.c.) reduced the above changes significantly. In contrast to TNF-α and IL-1, IL-10 production and the level of its mRNA of synoviocytes in AA rats were apparently decreased. CMA (2, 5 and 10mg/kg, s.c.) markedly increased IL-10 in synoviocytes at protein and transcription level. The results indicated that CMA had a beneficial effect on rats AA due to modulating inflammatory cytokines production of synoviocytes, which played a crucial role in pathogenesis of this disease.

Herbal formulation, Yukmi-jihang-tang-Jahage, regulates bone resorption by inhibition of phosphorylation mediated by tyrosine kinase Src and cyclooxygenase expression

Anti-bone resorption properties of the Korean herbal medicine, Yukmi-jihang-tang (YJ), which is comprised of seven herbs such as Rehmannia glutinosa Libosch, Dioscorea japonica THUNB, Cornus officinalis SIEB et. ZUCC, Smilax glabra ROXB, Paeonia suffruticosa ANDR, Alisma platago-aquatica var. orientale SAMUELS and Hominis placenta, were investigated. Cyclooxygenase-2 (COX-2) and tyrosine kinase involve on prostaglandin E2 (PGE2) production in mouse calvarial osteoblasts stimulated by cytokine interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and/or interleukin-6 (IL-6). IL-1beta and IL-6 and to a lesser extent TNF-alpha, enhanced COX-2 mRNA levels in calvarial osteoblasts. TGF-beta, YJ (100microg/ml) and their combinations of YJ+TGF-beta reduced the COX-2 mRNA level, PGE2 biosynthesis and bone resorption induced by IL-1beta, TNF-alpha, IL-6 or their combination. Finally, YJ inhibits in vitro and in vivo bone resorption by inhibition of phosphorylation of peptide substrates. The parathyroid hormone-induced bone resorption in mouse fetal long bone cultures was inhibited with an IC(50) of 16microg/ml. YJ dose-dependently reduced the hypercalcemia induced in mice by IL-1beta and partly prevented bone loss and microarchitectural changes in young ovariectomized rats, showing that the protective effect on bone was exerted via the inhibition of bone resorption. These results indicate that the synergy between IL-beta, TNF-alpha, IL-6 on PGE2 production is due to an enhanced gene expression of COX-2 and that tyrosine kinase(s) are involved in the signal transduction of COX-2 in mouse calvarial osteoblasts. Thus, YJ as a possible Src family kinase inhibitor may be useful for the treatment of diseases associated with elevated bone loss. This result also suggested that the YJ extracts is effective for bone resorptive action in bone cells.

Transforming growth factor-beta1 to the bone

TGF-beta1 is a ubiquitous growth factor that is implicated in the control of proliferation, migration, differentiation, and survival of many different cell types. It influences such diverse processes as embryogenesis, angiogenesis, inflammation, and wound healing. In skeletal tissue, TGF-beta1 plays a major role in development and maintenance, affecting both cartilage and bone metabolism, the latter being the subject of this review. Because it affects both cells of the osteoblast and osteoclast lineage, TGF-beta1 is one of the most important factors in the bone environment, helping to retain the balance between the dynamic processes of bone resorption and bone formation. Many seemingly contradictory reports have been published on the exact functioning of TGF-beta1 in the bone milieu. This review provides an overall picture of the bone-specific actions of TGF-beta1 and reconciles experimental discrepancies that have been reported for this multifunctional cytokine.

Suppressive effects of a water extract of Ulmus davidiana Planch (Ulmaceae) on collagen-induced arthritis in mice

Ulmus davidiana Planch (Ulmaceae) has long been known to have anti-inflammatory and protective effects on damaged tissue, inflammation and bone resorption. Therefore, this study was undertaken to address (1) whether the water extract of the bark of Ulmus davidiana Planch (Ulmaceae) (UD) can modulate the expression of inducible inflammatory cytokines in mice; (2) in order to assess the therapeutic effects of UD in collagen-induced arthritis (CIA) in mice. DBA/1 mice were immunized with bovine type II collagen. After a second collagen immunization, mice were treated with UD orally at 100mg/kg once a day for 3 weeks. Paws were evaluated macroscopically for redness, swelling and deformities. The levels of TNF-alpha and IL-1beta in the ankle were examined. The severity of arthritis within the knee joints was evaluated by histological assessment of cartilage destruction and pannus formation. Administration of UD significantly suppressed the progression of CIA and inhibited the production of TNF-alpha and IL-1beta in the paws. The erosion of cartilage was dramatically reduced in mouse knees after treatment with UD. In the serum of UD-treated mice, the levels of IL-4 and IL-10, anti-inflammatory cytokines, were increased. From the results, it was concluded that administration of UD has therapeutic effects on CIA including protection of cartilage and RA for a potential therapy.