Cytokines play a pivotal role in maintaining bone homeostasis. Osteoclasts (OCs), the sole bone resorbing cells, are regulated by numerous cytokines. Macrophage colony-stimulating factor and receptor activator of NF-κB ligand play a central role in OC differentiation, which is also termed osteoclastogenesis. Osteoclastogenic cytokines, including tumor necrosis factor-α, IL-1, IL-6, IL-7, IL-8, IL-11, IL-15, IL-17, IL-23, and IL-34, promote OC differentiation, whereas anti-osteoclastogenic cytokines, including interferon (IFN)-α, IFN-β, IFN-γ, IL-3, IL-4, IL-10, IL-12, IL-27, and IL-33, downregulate OC differentiation. Therefore, dynamic regulation of osteoclastogenic and anti-osteoclastogenic cytokines is important in maintaining the balance between bone-resorbing OCs and bone-forming osteoblasts (OBs), which eventually affects bone integrity. This review outlines the osteoclastogenic and anti-osteoclastogenic properties of cytokines with regard to osteoimmunology, and summarizes our current understanding of the roles these cytokines play in osteoclastogenesis.
Cytokines ; Homeostasis ; Interferons ; Interleukin-1 ; Interleukin-10 ; Interleukin-11 ; Interleukin-12 ; Interleukin-15 ; Interleukin-17 ; Interleukin-23 ; Interleukin-27 ; Interleukin-3 ; Interleukin-33 ; Interleukin-4 ; Interleukin-6 ; Interleukin-7 ; Interleukin-8 ; Macrophage Colony-Stimulating Factor ; Necrosis ; Osteoblasts ; Osteoclasts ; RANK Ligand

BACKGROUND: The megakaryopoiesis and platelet production is regulated by several hematopoietc factors such as thrombopoietin (TPO), interleukin-11 (IL-11) and interleukin-3 (IL-3). IL-11 is a potent stimulator of megakaryopoiesis in vivo, and acts primarily as a megakaryocyte maturation factor in vitro and it can act synergistically with IL-3 and TPO. We performed this study to investigate the effects of recombinant human IL-11 (rhIL-11) with other hematopoietic factors on megakaryocyte colony formation in vitro. METHODS: CD34+ cells were separated from umbilical cord blood and megakaryocyte colonies using MegaCult Assay Kit were cultured with rhIL-11, recombinant human IL-3 (rhIL-3), and recombinant human TPO (rhTPO) for 7 and 14 days. The number and percentage of CD34+ and CD41a+ cells were determined by flowcytometry. RESULTS: The number of CD41a+ cells were 0.54+/-0.05x10(4) (rhIL-11 100 ng/ml), 5.32+.-0.23x10(4) (rhIL-3 100 ng/ml), and 8.76+/-0.15x10(4) (rhTPO 50 ng/ml) of total expanded cells during the culture of the purified CD34+ cells in liquid phase for 7 days. The number of CD41a+ cells were increased to 7.47+/-0.69x10(4) (rhIL-3 rhIL-11), 11.92+/-0.19x10(4) (rhTPO rhIL-11) of total expanded cells, respectively, during the culture of the purified CD34+ cells in liquid phase for 7 days in the presence of rhIL-11 (100 ng/ml). When the purified CD34+ cells were cultured in semisolid media including various concentration of rhIL-11, the megakaryocyte colonies were not formed. When the purified CD34+ cells were cultured with rhIL-11 and rhTPO or with rhIL-11 and rhIL-3, the number of megakaryocyte colonies were increased compared with rhTPO or rhIL-3 alone. CONCLUSION: These results indicate that IL-11 exerts a potent proliferative activity to colony forming unit-megakaryocyte from human umbilical cord blood, and it acts with other hematopoietic factors synergistically
Blood Platelets ; Fetal Blood* ; Humans ; Interleukin-11* ; Interleukin-3 ; Megakaryocytes ; Thrombopoietin ; Umbilical Cord*

OBJECTIVETo investigate the binding characteristics of interleukin 11 (IL-11) analogue-cyclic nonapeptide c(Cys-Gly-Arg-Arg-Ala-Gly-Gly-Ser-Cys) NH2 C30H54N16O10S2, c(CGRRAGGSC), and human prostate cancer PC-3 cells.

METHODSc(CGRRAGGSC) was labeled with fluorescent dye LSS670, and the location of LSS670-cyclic nonapeptide in the PC-3 cells was investigated by fluorescent microscopy. Flow cytometry was used to detect the fluorescence intensity of the in vitro binding of LSS670-c (CGRRAGGSC) to PC-3 cells and calculate its IC50 and Ki in competitive inhibition experiments. 99Tcm-DTPA-c(CGRRAGGSC) was synthesized by the reaction of 99mTcO4- with c(CGRRAGGSC). The binding characteristics of 99mTc-DTPA-c(CGRRAGGSC) and IL11R in the PC-3 cells were analyzed by radioreceptor assay. Bmax and Kd were calculated in saturability and reversibility experiments.

RESULTSThe binding of LSS670-c(CGRRAGGSC) to the PC-3 cells showed the characteristics of saturability and concentration-time dependence. Unlabeled c(CGRRAGGSC) and LSS670-c(CGRRAGGSC) exhibited a competitive inhibition on the PC-3 cells (IC50 = [6.31 +/- 0.12] nmol/L, Ki = [2.11 +/- 0.14] nmol/L). Fluorescence was mainly distributed in the cell membrane (Kd = [0.32 +/- 0.02] nmol/L, Bmax = [754 +/- 34] fmol/mg pro).

CONCLUSIONc (CGRRAGGSC) could bind PC-3 cells through a receptor-mediated pathway.

Cell Line, Tumor ; Humans ; Interleukin-11 ; metabolism ; Male ; Peptides ; metabolism ; Prostatic Neoplasms ; metabolism ; Protein Binding

PURPOSE: Recent studies have demonstrated and suggested that Interleukin (IL) -10 and IL-11 are implicated in the pathophysiology of RSV infection and may act in the regulation of inflammatory response. We measured IL-10 and IL-11 in nasal secretions of infants with acute RSV bronchiolitis to investigate if there is any difference in the production of these anti-inflammatory cytokines between atopic and non-atopic subjects. METHODS: We measured IL-10, IL-11 in nasal secretions of 44 infants (20 were atopic) with acute RSV bronchiolitis. The nasal secretion samples were obtained from patients on admission and stored immediately at -70degrees C until analysis. Atopy was defined as having at least one positive skin prick test to common allergens, a positive history of atopic dermatitis or age-matched, high serum IgE level. RESULTS: IL-10 and IL-11 increased significantly in nasal secretion of infants with acute RSV bronchiolitis. Both IL-10 and IL-11 were significantly lower in atopic patients than in non-atopic patients. There was no significant relation between the severity of symptoms and IL-10 or IL-11 levels. CONCLUSION: Our study showed that both IL-10 and IL-11 increased in nasal secretion during acute RSV bronchiolitis, and the levels were significantly lower in atopic patients than in non-atopic patients. It suggests that the airway inflammation induced by RSV may be different between atopic and non-atopic patients and this may be associated with lower induction of these anti-inflammatory cytokines in atopic patients.
Allergens ; Bronchiolitis* ; Cytokines* ; Dermatitis, Atopic ; Humans ; Immunoglobulin E ; Infant ; Inflammation ; Interleukin-10 ; Interleukin-11 ; Interleukins ; Respiratory Syncytial Viruses* ; Skin

PURPOSE: The platelet synthesis is extremely variable after intravenous immunoglogulin injection (IVIG) in acute idiopathic thrombocytopenic purpura (ITP). To investigate the size variation of platelet according to the time sequence of ITP, the relationship between platelet number and mean platelet volume (MPV) was analyzed. METHODS: Twenty acute ITP patients who showed abrupt increase of platelets within 48 hours after IVIG were selected. We checked the platelet number and MPV, thereafter analyzed the relationship. RESULTS: At the early phase of ITP before IVIG, MPV was normal or slightly decreased. However, as the number of platelet increased after IVIG, MPV increased together until platelet count reached 100, 000/mm3. The MPV decreased afterward, therefore the platelet mass was preserved. CONCLUSION: At the early phase of ITP before the increase of platelet, MPV decreased in spite of low number of platelet. After IVIG, there was an abrupt increase of MPV with platelet number. There might be some contributing factors for these, particularly IL-6, IL-11 and thrombopoietin. Now, we need more experimental data to explain these findings.
Blood Platelets* ; Humans ; Immunoglobulins* ; Immunoglobulins, Intravenous ; Interleukin-11 ; Interleukin-6 ; Mean Platelet Volume* ; Platelet Count* ; Purpura, Thrombocytopenic, Idiopathic* ; Thrombopoietin

Lysophosphatidic acid (LPA) is known to play a critical role in breast cancer metastasis to bone. In this study, we tried to investigate any role of LPA in the regulation of osteoclastogenic cytokines from breast cancer cells and the possibility of these secretory factors in affecting osteoclastogenesis. Effect of secreted cytokines on osteoclastogenesis was analyzed by treating conditioned media from LPA-stimulated breast cancer cells to differentiating osteoclasts. Result demonstrated that IL-8 and IL-11 expression were upregulated in LPA-treated MDA-MB-231 cells. IL-8 was induced in both MDA-MB-231 and MDA-MB-468, however, IL-11 was induced only in MDA-MB-231, suggesting differential LPARs participation in the expression of these cytokines. Expression of IL-8 but not IL-11 was suppressed by inhibitors of PI3K, NFkB, ROCK and PKC pathways. In the case of PKC activation, it was observed that PKCδ and PKCμ might regulate LPA-induced expression of IL-11 and IL-8, respectively, by using specific PKC subtype inhibitors. Finally, conditioned Medium from LPA-stimulated breast cancer cells induced osteoclastogenesis. In conclusion, LPA induced the expression of osteolytic cytokines (IL-8 and IL-11) in breast cancer cells by involving different LPA receptors. Enhanced expression of IL-8 by LPA may be via ROCK, PKCu, PI3K, and NFkB signaling pathways, while enhanced expression of IL-11 might involve PKCδ signaling pathway. LPA has the ability to enhance breast cancer cells-mediated osteoclastogenesis by inducing the secretion of cytokines such as IL-8 and IL-11.
Breast Neoplasms* ; Breast* ; Culture Media, Conditioned ; Cytokines ; Interleukin-11 ; Interleukin-8 ; Neoplasm Metastasis ; Osteoclasts ; Receptors, Lysophosphatidic Acid

BACKGROUND: It is well known that excessive thyroid hormone in the body is associated with bone loss. However, the mechanism by which thyroid hormone affects bone cell metabolism remains unclear. It has been shown that thyroid hormones stimulate osteoclastic bone resorption indirectly via some unknown mediators secreted by osteoblasts, This study was undertaken to determine if interleukin-6 (IL-6) or interleukin-11 (IL-l1) could be the mediator (s) of thyroid hormone-induced bone loss. METHODS: We treated primary cultured human bone rnarrow stromal cells with 3,5,3-triiodo-thyronine (T) and measured basal and interleukin-l (IL-1)-stimulated IL-6/IL-ll production. We also investigated the possible modulating effect of 17B-estradiol (17B-E2.) on thyroid hormone action. RESULTS: T3 at 10 (-12) ~ 10 (-8) M concentration, significantly increased the basal IL-6 production in a dose-dependent manner, and also potentiated the stimulatory effect of IL-1 on IL-6 production. However, T failed to elicit a detectable effect on basal or IL-1-stimulated IL-11 production. Treat#ment with l7B-E2. inhibited IL-1-stimulated IL-6 production, but the effects of T3 on IL-6 production were not affected by 17/B-E. CONCLUSION: These results suggest that thyroid hormone may increase bone resorption by increasing basal IL-6 production and potentiating IL-1-induced IL-6 production from osteoblast-lineage cells, and these effects were independent of estrogen status.
Bone Marrow* ; Bone Resorption ; Estradiol ; Estrogens ; Humans* ; Interleukin-1 ; Interleukin-11* ; Interleukin-6* ; Mesenchymal Stromal Cells* ; Metabolism ; Osteoblasts ; Osteoclasts ; Osteoporosis ; Stromal Cells ; Thyroid Gland* ; Thyroid Hormones

Animals ; Blood Coagulation ; drug effects ; Blood Platelets ; drug effects ; Female ; Haplorhini ; Humans ; Interleukin-11 ; pharmacology ; Male ; Platelet Count ; Thrombopoietin ; pharmacology

A DNA fragment encoding recombinant human interleukin 11 (hrIL-11) was obtained by PCR from previously constructed pET24a-hrIL-11 plasmid. Then pET21a-hrIL-11 expression vector was constructed routinely and transformed into BL-21(DE3). By the induction of Isopropyl-1-thio-beta-D-galactoside (IPTG), hrIL-11 protein was highly expressed at about 20% of the total bacterial proteins and was identified by Western blot. After purification with Ni-NTA affinity chromatography and refolding with renaturation buffer, the purity of the target hrIL-11 protein reached 95% and its biology activity was 1 x 10(6) IU/mg, determined by stimulating the proliferation of T1165, which facilitates further researches into effects of IL-11 on platelet proliferation and other function.
Escherichia coli ; metabolism ; Genetic Vectors ; genetics ; Humans ; Interleukin-11 ; genetics ; metabolism ; Recombinant Proteins ; genetics ; isolation & purification ; metabolism

To observe the expression changes of interleukin-11 (IL-11) and its receptor in mice with pulmonary fibrosis. 
 Methods: C57BL/6 mice were randomly divided into a control group and a bleomycin (BLM) group (6 mice per group). BLM was injected into mice to induce idiopathic pulmonary fibrosis, while 50 μL PBS was injected into the control rats. The lung tissue was collected 21 d later. HE staining was used to observe morphological changes in lung tissue. Real-time PCR was used to detect IL-11 and its receptor gene expression. Western blot and immunohistochemical staining were used to detect IL-11 receptor expression. ELISA was used to detect the content of serum IL-11 in mice. In addition, the gene and protein expression of IL-11 receptor in mouse fibroblasts were detected by real-time PCR and Western blot, respectively. 
 Results: HE staining showed a significant change in pulmonary fibrosis in mice 21 d after BLM injection. The IL-11 mRNA expression in lung and IL-11 level in serum were up-regulated. The gene and protein expression of IL-11 receptor in mice with pulmonary fibrosis were significantly increased. The results from the cell experiments showed that the gene and protein expression of IL-11 receptor in mouse fibroblasts were significantly increased by TGF-β1.
 Conclusion: The expression of IL-11 and its receptor are up-regulated in mice with pulmonary fibrosis induced by BLM, which might be an important mechanism for the development of pulmonary fibrosis.
Animals ; Bleomycin ; Gene Expression Regulation ; Idiopathic Pulmonary Fibrosis ; physiopathology ; Interleukin-11 ; genetics ; Lung ; metabolism ; Mice ; Mice, Inbred C57BL ; Rats