Adseverin is a Ca2+-dependent actin filament-severing protein that has been reported to regulate exocytosis via rearrangements of the actin cytoskeleton in secretory cells. However, the role of adseverin in bone cells has not yet been well characterized. Here, we investigated the role of adseverin in osteoclastogenesis using primary osteoclast precursor cells. Adseverin expression was upregulated during RANKL (receptor activator of nuclear factor-kappaB ligand)-induced osteoclast differentiation. Moreover, genetic silencing of adseverin decreased the number of osteoclasts generated by RANKL. Adseverin knockdown also suppressed the RANKL-mediated induction of nuclear factor of activated T-cell c1 (NFATc1), which is a key transcription factor in osteoclastogenesis. In addition, adseverin knockdown impaired bone resorption and the secretion of bone-degrading enzymes from osteoclasts. These effects were accompanied by decreased NFATc1 expression and the activation of nuclear factor-kappaB. Collectively, our results indicate that adseverin has a crucial role in osteoclastogenesis by regulating NFATc1.
Active Transport, Cell Nucleus ; Animals ; Bone Resorption/genetics/metabolism/pathology ; Cell Differentiation ; Cells, Cultured ; Female ; Gelsolin/genetics/*metabolism ; Gene Knockdown Techniques ; Humans ; Mice, Inbred ICR ; NF-kappa B/metabolism ; NFATC Transcription Factors/*metabolism ; Osteoclasts/*cytology/metabolism/pathology ; RANK Ligand/*metabolism

This study is to observe the effects of methopterin on the activation and bone resorption function of murine osteoclasts, which were obtained by induction from bone marrow cell and purified to the purity of 70%-80%. The mechanism underlying the inhibitory effects of methopterin on inflammatory bone destruction was explored. MTT method was used to determine the effect of methopterin on the proliferation of osteoclasts. Flow cytometric analysis was used to determine the effect of methopterin on the apoptosis of osteocalsts. TRAP stain, bone resorption lacuna stain and measurement of lacuna area were executed to determine the effects of methopterin on the activation and function of osteoclasts. ELISA method was used to determine the effect of methopterin on the MMP-9 secretion from osteoclasts. RT-PCR method was used to determine the effect of methopterin on the mRNA expression of RANK and MMP-9 in osteoclasts. The results showed that methopterin (0.1-10 micromol x L(-1)) inhibited the proliferation of osteoclasts, methopterin (0.1-10 micromol x L(-1)) could inhibit the activation and bone resorption function of osteoclasts and induced the apoptosis of osteoclasts. Methopterin (0.01-10 micromol x L(-1)) also decreased the mRNA expression of RANK, but only at 1-10 micromol x L(-1) decreased the mRNA expression of MMP-9. These results indicated that there were intense relation between the inhibitory effects on the activation and function of osteoclasts and the inhibition of inflammatory bone destruction by methopterin.
Animals ; Antirheumatic Agents ; pharmacology ; Apoptosis ; drug effects ; Bone Resorption ; pathology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Male ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Methotrexate ; pharmacology ; Mice ; Mice, Inbred C57BL ; Osteoclasts ; cytology ; metabolism ; RANK Ligand ; genetics ; metabolism ; RNA, Messenger ; metabolism

The OPG/RANKL/RANK system plays an important role in osteoclastogenesis and represents a great progress in bone biology. RANKL, which expresses on the surface of osteoblast/stromal cells and activated T cells, binds to RANK on the osteoclastic precursors or mature osteoclasts, and promotes osteoclastogenesis and bone resorption. While osteoprotegerin (OPG), which is expressed by osteoblasts/stromal cells, strongly inhibits bone resorption by binding to its ligand RANKL and thereby blocks the interaction between BANKL and RANK. A number of cytokines and hormones exert their effects on bone metabolism by regulating the OPG/RANKL ratio in the bone marrow microenvironment. RANK is also expressed on mammary epithelial cells and RANKL expression in these cells is induced by pregnancy hormones, RANKL and RANK are essential for the formation of the lactating mammary gland and the transmission of maternal calcium to neonates in mammalian species. Modulation of these systems provides a unique opportunity to develop novel therapeutics to inhibit bone loss in osteoporosis, rheumatoid arthritis, and bone metastasis of cancer. Further research should be focused on the cooperation of OPG/RANKL/RANK system with other signal pathways and the interactions among bone remodeling, immune system and endocrinology system. Currently, the development of OPG analogues or compounds which may stimulate OPG expression is becoming an attractive industry which may be profitable to both patients and manufacturers.
Animals ; Bone Resorption ; immunology ; metabolism ; Humans ; Osteoclasts ; cytology ; metabolism ; pathology ; Osteogenesis ; drug effects ; genetics ; immunology ; Osteoprotegerin ; metabolism ; physiology ; RANK Ligand ; metabolism ; physiology ; Receptor Activator of Nuclear Factor-kappa B ; metabolism ; pharmacology ; physiology ; T-Lymphocytes ; drug effects ; immunology

Osteoarthritis (OA) is an age-related joint disease that is characterized by degeneration of articular cartilage and chronic pain. Oxidative stress is considered one of the pathophysiological factors in the progression of OA. We investigated the effects of grape seed proanthocyanidin extract (GSPE), which is an antioxidant, on monosodium iodoacetate (MIA)-induced arthritis of the knee joint of rat, which is an animal model of human OA. GSPE (100 mg/kg or 300 mg/kg) or saline was given orally three times per week for 4 weeks after the MIA injection. Pain was measured using the paw withdrawal latency (PWL), the paw withdrawal threshold (PWT) and the hind limb weight bearing ability. Joint damage was assessed using histological and microscopic analysis and microcomputerized tomography. Matrix metalloproteinase-13 (MMP13) and nitrotyrosine were detected using immunohistochemistry. Administration of GSPE to the MIA-treated rats significantly increased the PWL and PWT and this resulted in recovery of hind paw weight distribution (P < 0.05). GSPE reduced the loss of chondrocytes and proteoglycan, the production of MMP13, nitrotyrosine and IL-1beta and the formation of osteophytes, and it reduced the number of subchondral bone fractures in the MIA-treated rats. These results indicate that GSPE is antinociceptive and it is protective against joint damage in the MIA-treated rat model of OA. GSPE could open up novel avenues for the treatment of OA.
Analgesics/*administration & dosage ; Animals ; Antioxidants/*administration & dosage ; Bone Resorption ; Disease Models, Animal ; Gene Expression Regulation ; Humans ; Interleukin-1beta/genetics/metabolism ; Iodoacetates/administration & dosage ; Knee Joint/*drug effects/metabolism/pathology ; Male ; Matrix Metalloproteinase 13/genetics/metabolism ; Osteoarthritis/chemically induced/*drug therapy/physiopathology ; Pain ; Plant Extracts/administration & dosage ; Proanthocyanidins/*administration & dosage ; Rats ; Rats, Wistar ; Seeds ; Tomography, Emission-Computed ; Tyrosine/analogs & derivatives/metabolism ; Vitis/immunology

Osteoarthritis (OA) is an age-related joint disease that is characterized by degeneration of articular cartilage and chronic pain. Oxidative stress is considered one of the pathophysiological factors in the progression of OA. We investigated the effects of grape seed proanthocyanidin extract (GSPE), which is an antioxidant, on monosodium iodoacetate (MIA)-induced arthritis of the knee joint of rat, which is an animal model of human OA. GSPE (100 mg/kg or 300 mg/kg) or saline was given orally three times per week for 4 weeks after the MIA injection. Pain was measured using the paw withdrawal latency (PWL), the paw withdrawal threshold (PWT) and the hind limb weight bearing ability. Joint damage was assessed using histological and microscopic analysis and microcomputerized tomography. Matrix metalloproteinase-13 (MMP13) and nitrotyrosine were detected using immunohistochemistry. Administration of GSPE to the MIA-treated rats significantly increased the PWL and PWT and this resulted in recovery of hind paw weight distribution (P < 0.05). GSPE reduced the loss of chondrocytes and proteoglycan, the production of MMP13, nitrotyrosine and IL-1beta and the formation of osteophytes, and it reduced the number of subchondral bone fractures in the MIA-treated rats. These results indicate that GSPE is antinociceptive and it is protective against joint damage in the MIA-treated rat model of OA. GSPE could open up novel avenues for the treatment of OA.
Analgesics/*administration & dosage ; Animals ; Antioxidants/*administration & dosage ; Bone Resorption ; Disease Models, Animal ; Gene Expression Regulation ; Humans ; Interleukin-1beta/genetics/metabolism ; Iodoacetates/administration & dosage ; Knee Joint/*drug effects/metabolism/pathology ; Male ; Matrix Metalloproteinase 13/genetics/metabolism ; Osteoarthritis/chemically induced/*drug therapy/physiopathology ; Pain ; Plant Extracts/administration & dosage ; Proanthocyanidins/*administration & dosage ; Rats ; Rats, Wistar ; Seeds ; Tomography, Emission-Computed ; Tyrosine/analogs & derivatives/metabolism ; Vitis/immunology