B cell activation factor (BAFF) is a novel member of the TNF ligand superfamily, mainly produced by myeloid cells. BAFF has been shown to participate in B-cell survival and B- and T-cell maturation. BAFF expression in adipocytes has been recently demonstrated. In the current study, we verified that BAFF expression is increased during adipocyte differentiation. BAFF expression was augmented by TNF-alpha treatment and was decreased by rosiglitazone treatment. BAFF secretion in lean and in ob/ob mice sera were compared and smaller amount of BAFF was secreted in ob/ob mice. mRNA and protein expression were different between epididymal and visceral adipose tissue. BAFF expression was also increased in ob/ob mouse adipose tissue. We sought to identify known BAFF receptors (BAFF-R, BCMA, and TACI) in adipocytes, and determined that all three were present and upregulated during adipocyte differentiation. However, the expression of TACI was distinct from that of BAFF-R and BCMA under TNF-alpha and BAFF ligand treatment. BAFF-R and BCMA expression levels were upregulated under pro-inflammatory conditions, but TACI was reduced. Conversely, BAFF-R and BCMA expression levels were downregulated by rosiglitazone treatment, but TACI was increased. Taken together, our results suggest that BAFF may be a new adipokine, representing a link between obesity and inflammation.
Adipocytes/cytology ; Adipokines/biosynthesis/*physiology ; Animals ; B-Cell Activating Factor/biosynthesis/*physiology ; B-Cell Activation Factor Receptor/metabolism ; Cell Differentiation ; Hypoglycemic Agents/pharmacology ; Inflammation/*metabolism ; Mice ; Obesity/*metabolism ; Thiazolidinediones/pharmacology ; Tumor Necrosis Factor-alpha/pharmacology

The study was purposed to detect BAFF/APRIL gene expression changes in bone marrow mononuclear cells (BMMNC) and myeloma cell line U266 after interference with glucocorticoid and bortezomib. After separation of BMMNC from 7 patients with multiple myeloma, BAFF/APRIL mRNA expression in BMMNC and U266 cell line was detected by real-time PCR after treated with dexamethasone 100, 200 µg/ml, methylprednisolone 100, 200 µg/ml, bortezomib 0.1 µg/ml alone and dexamethasone or methylprednisolone combined with bortezomib respectively for 48 hours. The results showed that U266 cells and BMMNC of untreated MM patients highly expressed BAFF/APRIL genes. When dexamethasone, methylprednisolone or bortezomib was added to U266 cells or BMMNC alone, BAFF/APRIL gene expression decreased as compared with the blank control (p < 0.01). The inhibiting effect of bortezomib to BAFF/APRIL expression was obviously strong(p < 0.05). When dexamethasone or methylprednisolone combined with bortezomib, the BAFF/APRIL gene expression further decreased compared with dexamethasone or methylprednisolone alone (p < 0.01). As compared with the group of methylprednisolone combined with bortezomib, BAFF/APRIL gene expression decreased in dexamethasone combined with bortezomib with a statistically significant difference (p < 0.05). It is concluded that the expression of BAFF/APRIL gene is down-regulated after bing treated with glucocorticoids and bortezomib, which suggests that besides the glucocorticoid receptor and proteasomes targets, BAFF/APRIL and their receptor sites may be new targets of glucocorticoids and bortezomib.
B-Cell Activating Factor ; genetics ; metabolism ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; drug effects ; Glucocorticoids ; pharmacology ; Humans ; Multiple Myeloma ; metabolism ; Pyrazines ; pharmacology ; RNA, Messenger ; genetics ; Tumor Necrosis Factor Ligand Superfamily Member 13 ; genetics ; metabolism

B cells play an important role in the pathogenesis of rheumatoid arthritis (RA). High levels of B cell activating factor (BAFF) are detected in autoimmune diseases. BAFF and BAFF receptor (BAFF-R) are expressed in B and T cells of RA synovium. The study was undertaken to identify the NF-kappaB signal pathway involved in the induction of BAFF-R in human B cells. Immunohistochemical staining of NF-kappaB p65, NF-kappaB p50, BAFF, and BAFF-R was performed on sections of synovium from severe and mild RA and osteoarthritis (OA) patients. Peripheral blood mononuclear cells (PBMCs) were isolated from control and RA patients and B cells were isolated from controls. BAFF-R was analyzed by flow cytometry, realtime PCR and confocal staining after treatment with NF-kappaB inhibitors. NF-kappaB p65, NF-kappaB p50, BAFF, and BAFF-R were highly expressed in severe RA synovium relative to mild RA synovium or OA synovium. BAFF-R expression was reduced by NF-kappaB inhibitors in PBMCs and B cells from normal controls. We also showed reduction in expression of BAFF-R via inhibition of the NF-kappaB pathway in PBMCs of RA patients. BAFF/BAFF-R signaling is an important mechanism of pathogenesis in RA and that BAFF-R reduction by NF-kappaB blocking therapy is another choice for controlling B cells in autoimmune diseases such as RA.
Arthritis, Rheumatoid/genetics/*metabolism/pathology/physiopathology ; B-Cell Activating Factor/genetics/metabolism ; B-Cell Activation Factor Receptor/genetics/*metabolism ; B-Lymphocytes/*drug effects/immunology/metabolism/pathology ; Cell Separation ; Cells, Cultured ; Disease Progression ; Enzyme Inhibitors/pharmacology ; Flow Cytometry ; Gene Expression Regulation/immunology ; Humans ; Immunohistochemistry ; NF-kappa B/*metabolism ; Signal Transduction/immunology ; Synovial Membrane/*pathology ; T-Lymphocytes/drug effects/immunology/metabolism/pathology ; Transcriptional Activation/drug effects

<b>AIMb>To investigate effects of hsBAFF synthesized in Escherichia coli on spleen B lymphocyte immune response and its intracellular free Ca2+ ([Ca2]i]) signaling in mice.

<b>METHODSb>Twenty ICR mice, half males-half females, were chosen and randomly divided into a normal control group (n=10) and a hsBAFF treatment group (n-10). The mice in hsBAFF treatment group were given abdominal cavity injection of hsBAFF solution which was diluted with phosphate buffered saline (PBS) at dosage of 0.1 mg/kg body weight once each day for over eight days. The mice in control group were received abdominal injection of PBS at the same dose and frequency. Spleen B lymphocyte proliferation and its immune response to LPS stimulation in mice were evaluated using an MTT assay, and change of spleen B lymphocyte [Ca2+]i was assayed under a laser scanning confocal microscope.

<b>RESULTSb>B lymphocyte proliferation and its immune response to LPS stimulation were significantly higher in hsBAFF-treated mice than in control mice (P < 0.05). The B lymphocyte [Ca2+]i fluorescence intensity in hsBAFF-treated mice maintained at a relatively high level fluctuation, and its average intensity was significantly higher to that of control mice (P < 0.01), but change rate of the intensity was lower compared to that of control group.

<b>CONCLUSIONb>hsBAFF synthesized in Escherichia coli can enhance immune function in the body by increasing B lymphocyte proliferation and its immune response. hsBAFF-activated B lymphocyte function may be associated with increasing B lymphocytes [Ca2+]i.

Animals ; B-Cell Activating Factor ; immunology ; pharmacology ; B-Lymphocytes ; cytology ; drug effects ; immunology ; Calcium ; metabolism ; Calcium Signaling ; drug effects ; Cell Proliferation ; drug effects ; Female ; Male ; Mice ; Mice, Inbred ICR ; Spleen ; cytology ; drug effects ; immunology

3T3-L1 adipocytes express the B-cell-activating factor (BAFF) and three different BAFF receptors (BAFF-Rs). Furthermore, BAFF expression is regulated by inflammatory modulators, such as tumor necrosis factor-alpha and rosiglitazone. Here we investigated the function of BAFF in 3T3-L1 adipocytes and RAW 264.7 macrophages. We examined adipokine expression in 3T3-L1 adipocytes treated with 10 ng ml-1 BAFF. We also examined inflammatory molecule expression in RAW 264.7 macrophages treated with 10 or 100 ng ml-1 BAFF. We examined BAFF expression in the coculture of 3T3-L1 adipocytes and RAW 264.7 macrophages, as well as in white adipose tissue (WAT) of diet-induced obese (DIO) mice. We found that BAFF decreases leptin and adiponectin expression, but increases the expression of proinflammatory adipokines monocyte chemotactic protein-1, interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and haptoglobin. Coculturing the two cell types resulted in increased BAFF mRNA and protein expression, as well as modulation of BAFF-R mRNA expression in both cell types. These data indicate that BAFF might mediate adipocyte and macrophage interaction. When RAW 264.7 macrophages were treated with BAFF, BAFF-R expression was modulated as in coculture, and nitric oxide synthase and IL-6 expression increased. BAFF expression also increased in WAT of DIO mice. We propose that BAFF can regulate adipokine expression and possibly mediate adipocyte and macrophage interaction.
3T3-L1 Cells ; Adipocytes/drug effects/*metabolism ; Adipokines/genetics/*metabolism ; Adiponectin/genetics/metabolism ; Animals ; B-Cell Activating Factor/*metabolism/pharmacology ; Chemokine CCL2/genetics/metabolism ; Coculture Techniques ; Gene Expression Regulation/drug effects ; Haptoglobins/genetics/metabolism ; Inflammation Mediators/metabolism ; Interleukin-6/genetics/metabolism ; Leptin/genetics/metabolism ; Macrophages/drug effects/*metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Obese ; RNA, Messenger/genetics/metabolism

Wnt5a is a ligand that activates the noncanonical Wnt signaling pathways (beta-catenin-independent pathways). Human neutrophils expressed several Wnt5a receptors, such as Frizzled 2, 5 and 8. Stimulation of human neutrophils with Wnt5a caused chemotactic migration and the production of two important chemokines, CXCL8 and CCL2. CCL2 production by Wnt5a was mediated by a pertussis toxin-sensitive G-protein-dependent pathway. Wnt5a also stimulated the phosphorylation of three mitogen-activated protein kinases (MAPKs: ERK, p38 MAPK and JNK) and Akt. Inhibition of ERK, p38 MAPK or JNK by specific inhibitors induced a dramatic reduction in Wnt5a-induced CCL2 production. Supernatant collected from lipopolysaccharide-stimulated macrophages induced neutrophil chemotaxis, which was significantly inhibited by anti-Wnt5a antibody. Our results suggested that Wnt5a may contribute to neutrophil recruitment, mediating the inflammation response.
Activating Transcription Factor 2/metabolism ; Animals ; Cell Separation ; Chemokines/*biosynthesis ; Chemotaxis/*drug effects ; Culture Media, Conditioned/pharmacology ; Extracellular Signal-Regulated MAP Kinases/metabolism ; GTP-Binding Proteins/metabolism ; Humans ; JNK Mitogen-Activated Protein Kinases/metabolism ; Lipopolysaccharides/pharmacology ; Macrophages/drug effects/metabolism ; Mice ; NF-kappa B/metabolism ; Neutrophils/*cytology/drug effects/enzymology/*metabolism ; Pertussis Toxin/pharmacology ; Phosphatidylinositol 3-Kinases/metabolism ; Proto-Oncogene Proteins c-akt/metabolism ; Receptors, Wnt/metabolism ; Type C Phospholipases/metabolism ; Wnt Proteins/*pharmacology ; p38 Mitogen-Activated Protein Kinases/metabolism

Obesity is recognized as a chronic low-grade inflammatory state due to adipose tissue expansion being accompanied by an increase in the production of proinflammatory adipokines. Our group is the first to report that B-cell-activating factor (BAFF) is produced from adipocytes and functions as a proinflammatory adipokine. Here, we investigated how loss of BAFF influenced diet-induced obesity in mice by challenging BAFF-/- mice with a high-fat diet for 10 weeks. The results demonstrated that weight gain in BAFF-/- mice was >30% than in control mice, with a specific increase in the fat mass of the subcutaneous region rather than the abdominal region. Expression of lipogenic genes was examined by quantitative real-time PCR, and increased lipogenesis was observed in the subcutaneous adipose tissue (SAT), whereas lipogenesis in the epididymal adipose tissue (EAT) was reduced. A significant decrease in EAT mass resulted in the downregulation of inflammatory gene expression in EAT, and more importantly, overall levels of inflammatory cytokines in the circulation were reduced in obese BAFF-/- mice. We also observed that the macrophages recruited in the enlarged SAT were predominantly M2 macrophages. 3T3-L1 adipocytes were cultured with adipose tissue conditioned media (ATCM), demonstrating that EAT ATCM from BAFF-/- mice contains antilipogenic and anti-inflammatory properties. Taken together, BAFF-/- improved systemic inflammation by redistributing adipose tissue into subcutaneous regions. Understanding the mechanisms by which BAFF regulates obesity in a tissue-specific manner would provide therapeutic opportunities to target obesity-related chronic diseases.
3T3-L1 Cells ; Adipocytes/drug effects/metabolism ; Adiposity/*genetics ; Animals ; B-Cell Activating Factor/*genetics ; Cells, Cultured ; Culture Media, Conditioned/pharmacology ; Diet, High-Fat ; Disease Models, Animal ; Gene Knockout Techniques ; Inflammation/*genetics ; Lipogenesis/genetics ; Macrophages/metabolism ; Male ; Mice ; Mice, Knockout ; Obesity/*etiology

<b>AIMb>To investigate the effect of ginkgolide B on the proliferation of VSMC and the secretion of chemokines by U937 cells stimulated by oxLDL or PAF. In addition, to analyze whether the effect of oxLDL is mediated through PAF receptor.

<b>METHODSb>Using 3H-Tdr incorporation assay, the proliferation of VSMC was measured. The protein and mRNA level of MCP-1 and IL-8 in U937 cells were determined by RT-PCR and ELISA. Using Western blotting the p65 and IkappaB was quantified. The binding of oxLDL to U937 cell was measured by a radio-ligand binding assay of 3H-PAF.

<b>RESULTSb>Ginkgolide B inhibited, in dose-dependent manner, the proliferation of VSMC and the secretion of chemokines by U937 cells stimulated by oxLDL, and inhibited the oxLDL-induced p65 activation and depletion of IKappaB. oxLDL inhibited PAF binding to U937 cells.

<b>CONCLUSIONb>Ginkgolide B, as a PAF antagonist, possesses the effect of inhibiting the proliferation of VSMC and the secretion of chemokines by U937 cells stimulated by oxLDL in vitro. The effect of oxLDL is, at least in part, mediated through PAF receptor.

Animals ; Aorta, Thoracic ; cytology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Chemokine CCL2 ; biosynthesis ; genetics ; Diterpenes ; isolation & purification ; pharmacology ; Dose-Response Relationship, Drug ; Ginkgo biloba ; chemistry ; Ginkgolides ; Humans ; I-kappa B Proteins ; metabolism ; Interleukin-8 ; biosynthesis ; genetics ; Lactones ; isolation & purification ; pharmacology ; Lipoproteins, LDL ; pharmacology ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; Plants, Medicinal ; chemistry ; Platelet Activating Factor ; antagonists & inhibitors ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Synaptotagmin I ; metabolism ; U937 Cells

Skeletal fluorosis is a chronically metabolic bone disease with extensive hyperostosis osteosclerosis caused by long time exposure to fluoride. Skeletal fluorosis brings about a series of abnormal changes of the extremity, such as joint pain, joint stiffness, bone deformity, etc. Differentiation and maturation of osteoblasts were regulated by osteoclasts via Sema4D/Plexin-B1 signaling pathway. Furthermore, the differentiation and maturation of osteoclasts are conducted by osteoblasts via RANKL/RANK/OPG pathway. Both of these processes form a feedback circuit which is a key link in skeletal fluorosis. In this study, an osteoblast-osteoclast co-culture model in vitro was developed to illustrate the mechanism of skeletal fluorosis. With the increase of fluoride concentration, the expression level of Sema4D was decreased and TGF-β1 was increased continuously. OPG/RANKL mRNA level, however, increased gradually. On the basis of that, the inhibition of Sema4D/Plexin-B1/RhoA/ROCK signaling pathway caused by fluoride promoted the level of TGF-β1 and activated the proliferation of osteoblasts. In addition, osteroprotegerin (OPG) secreted by osteoblasts was up-regulated by fluoride. The competitive combination of OPG and RANKL was strengthened and the combination of RANKL and RANK was hindered. And then the differentiation and maturation of osteoclasts were inhibited, and bone absorption was weakened, leading to skeletal fluorosis.
Animals ; Antigens, CD ; genetics ; metabolism ; Cell Proliferation ; drug effects ; Feedback, Physiological ; Fetus ; Fluorides ; pharmacology ; GTPase-Activating Proteins ; genetics ; metabolism ; Gene Expression Regulation, Developmental ; Osteoblasts ; drug effects ; metabolism ; pathology ; Osteoclasts ; drug effects ; metabolism ; pathology ; Osteogenesis ; drug effects ; genetics ; Osteoprotegerin ; genetics ; metabolism ; RANK Ligand ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Receptor Activator of Nuclear Factor-kappa B ; genetics ; metabolism ; Receptors, Cell Surface ; genetics ; metabolism ; Semaphorins ; genetics ; metabolism ; Signal Transduction ; Transforming Growth Factor beta1 ; genetics ; metabolism ; rho-Associated Kinases ; genetics ; metabolism ; rhoA GTP-Binding Protein ; genetics ; metabolism