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Query: UNIPROT:P04141 (
granulocyte-macrophage colony-stimulating factor
)
6,790
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The effect of
parathyroid hormone
(
PTH
) on immunoglobulin (Ig) production and proliferation in the human B-cell lines CBL, SKW, and CESS was studied.
PTH
inhibited Ig production from all the B-cell lines in a dose-dependent manner during 5 days of culture. As little as 0.1 ng/ml was inhibitory.
PTH
also inhibited Ig production from cell lines stimulated by vasoactive intestinal peptide (VIP), interleukin 2 (IL-2), and IL-6. This inhibition was not due to decreased cell growth since proliferation was not affected and cell viability was always greater than 98%. In contrast to
PTH
, inactivated
PTH
or triiodothyronine failed to affect Ig production. Inhibition by
PTH
was blocked by anti-
PTH
serum, but not by control serum. Of the various cytokines tested, IL-4 reduced the
PTH
-induced inhibition of Ig production, whereas other cytokines, including IL-1 beta, IL-3, IL-5, interferon alpha (IFN-alpha), IFN-gamma, and
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
), failed to do so. The reducing effect of IL-4 was blocked by anti-IL-4 antibody but not by control antibody. Moreover, IFN-alpha and IFN-gamma, but not
GM-CSF
, overcame the reducing effect of IL-4.
PTH
also inhibited IgG, IgM, and IgA production by tonsillar B cells stimulated with Staphylococcus aureus Cowan strain I (SAC) and IL-6 without affecting proliferation. This inhibition was blocked by anti-IL-4 antibody but not by control antibody. These results indicate that, in addition to its regulatory effect on calcium metabolism,
PTH
also acts as an immunoregulatory factor, and that it interacts with the cytokine, IL-4.
...
PMID:Parathyroid hormone inhibits immunoglobulin production without affecting cell growth in human B cells. 145 31
We demonstrated that 125I-labeled human
parathyroid hormone
(1-34;8,18-Nle,34-Tyr)[[125I]hPTH(1-34)] bound specifically to hemopoietic blast cells supported by
granulocyte-macrophage colony-stimulating factor
. Half-maximal inhibition of binding was achieved at concentrations of unlabeled hPTH(1-34) of about 5 x 10(-9)M. Insulin and hPTH(39-68) did not compete for PTH binding sites. Specific binding of hPTH(1-34) was detected in neither macrophages nor multinucleated cells (MNC's). Furthermore, treatment of hemopoietic blast cells with hPTH(1-34) stimulated MNC formation, and the range of concentrations (10(-10)-10(-8)M) over which hPTH(1-34) caused these effects was similar to that which inhibited the binding of [125I]hPTH(1-34). These findings suggest the presence of a PTH receptor on osteoclast precursors and the direct effect of PTH on them, resulting in osteoclast-mediated bone resorption.
...
PMID:Existence of parathyroid hormone binding sites on murine hemopoietic blast cells. 255 Dec 92
Osteoblasts are the cells responsible for the secretion of collagen and ultimately the formation of new bone. These cells have also been shown to regulate osteoclast activity by the secretion of cytokines, which remain to be defined. In an attempt to identify these unknown cytokines, we have induced primary murine osteoblasts with two bone active agents,
parathyroid hormone
(
PTH
) and lipopolysaccharide (LPS) and analyzed the conditioned media (CM) for the presence of specific cytokines. Analysis of the CM was accomplished by functional, biochemical, and serological techniques. The data indicate that both
PTH
and LPS are capable of inducing the osteoblasts to secrete a cytokine, which by all of the techniques used, is indistinguishable from
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
). Secretion of
GM-CSF
is not constitutive and requires active induction. Production of the cytokine is dependent on the dose of
PTH
or LPS added. It has been demonstrated that the addition of
GM-CSF
to bone marrow cultures results in the formation of increased numbers of osteoclasts. Therefore, these data suggest that osteoblasts not only participate in bone remodeling by formation of new matrix but may regulate osteoclast activity indirectly by their ability to regulate hematopoiesis.
...
PMID:Parathyroid hormone and lipopolysaccharide induce murine osteoblast-like cells to secrete a cytokine indistinguishable from granulocyte-macrophage colony-stimulating factor. 264 17
Osteoblasts play a central role in the regulation of bone remodeling. Not only are they responsible for the formation of new bone, but they also regulate bone resorption. These cells also exert regulatory influences outside the bone in that they are able to regulate hematopoiesis. However, obtaining pure populations of osteoblasts devoid of contaminating cell types remains problematic. One approach to this problem is the use of cloned osteoblastic cell lines. To this end we have used MC3T3-E1, a cloned murine osteoblast cell line of C57BL/6 origin. We report that MC3T3-E1 cells respond to lipopolysaccharide (LPS) and, to a lesser extent,
parathyroid hormone
(
PTH
) by the secretion of
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
). However, 1,25-(OH)2D3, a potent activator of osteoblasts, fails to induce these cells to secrete
GM-CSF
. These results suggest that MC3T3-E1 cells respond to osteotropic agents in a hierarchical fashion. Secretion of
GM-CSF
is not constitutive but rather requires active induction of the cells. MC3T3 cells fail to secrete detectable levels of interleukin-2 (IL-2), IL-3, or IL-4, regardless of whether or not the cells are activated. The data indicate that MC3T3-E1 cells secrete cytokines in response to osteotropic agents in a way similar to that of normal primary osteoblasts. Therefore, MC3T3-E1 cells may serve as a good in vitro model for primary osteoblasts.
...
PMID:Osteotropic agents induce the differential secretion of granulocyte-macrophage colony-stimulating factor by the osteoblast cell line MC3T3-E1. 269 6
Colony-stimulating factor
-1 (CSF-1) is a hematopoietic growth factor that is released by osteoblasts and is recognized to play a critical role in bone remodeling in vivo and in vitro. CSF-1 is synthesized as a soluble or cell-surface protein. It is unclear, however, whether human osteoblasts express both molecular forms of CSF-1, and whether these isoforms can independently mediate osteoclastogenesis. In the present study, using a combination of quantitative reverse transcriptase polymerase chain reaction, flow cytometry, and Western immunoblot analysis, we have demonstrated that human osteoblast-like cells as well as primary human osteoblasts express the cell-surface form of CSF-1 both constitutively and in response to
parathyroid hormone
and tumor necrosis factor. Furthermore, using an in vitro co-culture system, we have shown that cell-surface CSF-1 alone is sufficient to support osteoclast formation. These findings may be especially significant in view of evidence that direct cell-to-cell contact is critical for osteoclast formation, and suggest that differential regulation of expression of the CSF-1 isoforms may influence osteoclast function modulated by osteotropic hormones.
...
PMID:The cell-surface form of colony-stimulating factor-1 is regulated by osteotropic agents and supports formation of multinucleated osteoclast-like cells. 946 6
Several lines of evidence indicate that estrogen inhibits
parathyroid hormone
(
PTH
)-induced bone resorption in vivo and in vitro. However, its precise mechanism remains unknown. The present study was performed to investigate whether osteoclast precursor cells possess the receptors for
PTH
/PTH-related protein (PTHrP) and/or estrogen and to clarify the mechanism by which estrogen affects
PTH
-induced osteoclast-like cell (Ocl) formation. The polymerase chain reaction (PCR) product corresponding in size to the mouse PTH/PTHrP receptor cDNA was detected in mouse hemopoietic blast cells supported by
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) as well as in osteoblastic MC3T3-E1 cells. The nucleotide sequence of the PTH/PTHrP receptor PCR product of hemopoietic blast cells was found to be 95.4% identical to that of PTH/PTHrP receptor cDNA of rat osteoblastic ROS cells. The PCR product corresponding in size to the mouse estrogen receptor cDNA was detected in mouse hemopoietic blast cells supported by
GM-CSF
as well as in MC3T3-E1 cells. The nucleotide sequence of the estrogen receptor PCR product of hemopoietic blast cells was completely identical to that of mouse estrogen receptor cDNA. 17Beta-estradiol (17beta-E2) but not 17alpha-E2 dose dependently antagonized Ocl formation stimulated by human (h)
PTH
(1-34) at a minimal effective concentration of 10(-10) M in the hemopoietic blast cell culture. 17Beta-E2 also significantly inhibited Ocl formation stimulated by 10(-8) M hPTHrP(1-34), while it did not affect 1,25-dihydroxyvitamin D3-induced Ocl formation. However, 10(-8) M 17beta-E2 significantly inhibited Ocl formation stimulated by dibutyryladenosine cAMP (10(-4) M) and Sp-cAMPS (10(-4) M), an activator of cAMP-dependent protein kinase (PKA) as well as forskolin (10(-5) M). In contrast, 17beta-E2 did not affect Ocl formation by either phorbol myristate acetate (10(-7) M), an activator of protein kinase C (PKC), or A23187 (10(-7) M), a calcium ionophore. The pretreatment with 17beta-E2 significantly inhibited Ocl formation induced by the combined treatment with
PTH
and PKC inhibitors (H7 or staurosporine), while it did not affect Ocl formation stimulated by the combined treatment with
PTH
and Rp-cAMPS, a PKA inhibitor. The present data indicate that estrogen inhibits
PTH
-stimulated Ocl formation by directly acting on hemopoietic blast cells, possibly through blocking a PKA pathway but not a calcium/PKC pathway.
...
PMID:Estrogen via the estrogen receptor blocks cAMP-mediated parathyroid hormone (PTH)-stimulated osteoclast formation. 961 Jul 50
The formation of multinucleated giant cells (MGCs) from monocytes/macrophages is controlled by various cytokines whose crucial roles are not fully understood. In this study, we found that interleukin (IL)-13 as well as IL-4 induced peripheral blood monocytes (PBMs) and monoblastic cell line, UG3, to differentiate into MGCs in the presence of macrophage colony-stimulating factor (M-CSF), while IL-2, IL-7 or IL-10 did not. The presence of M-CSF was essential to this MGC formation, because IL-3 or
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) could not replace M-CSF. IL-4 and IL-13 have been known to inhibit the formation of osteoclast-like cells in the presence of stroma cells or osteoblastic cells. But in our system without stroma cells, IL-4 or IL-13 induced some of characteristics of osteoclasts such as tartrate-resistant acid phosphatase (TRAP) activity, vitronectin receptor (vit-R) expression and resorptive activity for hydroxyapatite, but not the expression of receptors for
parathyroid hormone
or calcitonin. These results suggest possible involvement of IL-4 and IL-13 in MGCs and osteoclasts development, and UG3 may be useful to further investigate the roles of IL-4 and IL-13 in the formation and physiology of MGCs, and the relationship between these MGCs and osteoclasts.
...
PMID:IL-13 as well as IL-4 induces monocytes/macrophages and a monoblastic cell line (UG3) to differentiate into multinucleated giant cells in the presence of M-CSF. 987 26
Paraneoplastic syndromes including leukocytosis, thrombocytosis and hypercalcemia are occasionally seen in patients suffering from progressive malignant disorders. Recent studies have revealed the production of several humoral factors by tumor cells and normal splenic cells of tumor-bearing patients to be the major cause of these reactions.
Granulocyte-macrophage colony-stimulating factor
(
GM-CSF
), granulocyte-colony stimulating factor (G-CSF),
parathyroid hormone
-related peptide, interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF) have been implicated. We describe a 58-year-old Japanese man with squamous cell carcinoma (SCC) on the left sole, which developed in a deep linear scar after a train crash. He developed pulmonary and lymph node metastases, then leukocytosis (57,110/mm3 with 95% neutrophilia), thrombocytosis (86.3 x 10(4)/mm3), and hypercalcemia (7.0 mEq/1), and finally cachexia, followed by death. Serum G-CSF, IL-1 alpha, IL-1 beta, and TNF-beta were determined; revealing G-CSF and IL-1 beta levels were above the upper limits of their normal ranges at 39.2 pg/ml and 4.63 pg/ml, respectively. It is probable that these humoral factors were partially responsible for the paraneoplastic syndromes induced by the cutaneous SCC with metastasis in the present case.
...
PMID:Paraneoplastic syndromes of leukocytosis, thrombocytosis, and hypercalcemia associated with squamous cell carcinoma. 1040 79
In the search for a new class of bone-sparing agents, we have conducted random screening of the domestic chemical library using 45Ca release assay from prelabeled cultured neonatal mouse calvariae and identified a novel synthetic triazolotriazepine JTT-606 as a candidate for a potent inhibitor of bone resorption. JTT-606 inhibited 45Ca release dose dependently not only in the control calvarial culture but also in the stimulated cultures by interleukin-1alpha (IL-1alpha), fibroblast growth factor 2 (FGF-2), and
parathyroid hormone
(
PTH
). JTT-606 also inhibited both basal and stimulated osteoclast-like (OCL) cell formation in the coculture of mouse osteoblastic cells and bone marrow cells dose dependently, indicating its inhibitory effect on osteoclast differentiation. Ex vivo OCL cell formation by cultured bone marrow cells collected from ovariectomized (OVX) mice also was decreased dose dependently by in vivo application of JTT-606 to a level similar to that from sham-operated mice. Furthermore, JTT-606 inhibited resorbed pit formation by isolated mature osteoclasts as well as by unfractionated bone cells derived from rabbit long bones in the control and FGF-2-stimulated cultures dose dependently, indicating both the direct and the indirect actions of JTT-606 on mature osteoclast function. In addition, JTT-606 reduced production of IL-1alpha, tumor necrosis factor alpha (TNF-alpha), IL-6, and
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) in the human peripheral blood mononuclear cell culture. In vivo analyses of mature OVX rats revealed that the application of JTT-606 for 12 weeks increased the BMD of the lumbar spine and decreased the levels of serum osteocalcin and urine deoxypyridinoline to levels similar to those of 17beta-estradiol-treated OVX rats. We propose that JTT-606 may inhibit both osteoclast differentiation and function by down-regulating both the action and the production of bone resorptive factors. It is speculated that JTT-606 could be a potent agent for the treatment of osteopenic disorders with elevated osteoclastic bone resorption.
...
PMID:A novel synthetic triazolotriazepine derivative JTT-606 inhibits bone resorption by down-regulation of action and production of bone resorptive factors. 1078 Aug 59
There is accumulating evidence that T cells may be involved in osteoclastogenesis in a variety of murine systems. However, the precise role of human T cells in the regulation of osteoclast generation is still unclear. To address this issue, we investigated the effect of resting peripheral T cells on receptor activator of NF-kappaB ligand (RANKL)-induced osteoclast generation from human peripheral monocytes. Although osteoclasts were not generated in the culture of human peripheral blood mononuclear cells (PBMC) in the presence of RANKL and macrophage colony-stimulating factor (M-CSF), the addition of cyclosporine A (CsA), a potent inhibitor of T-cell function, resulted in the formation of an increasing number of lacunae resorption on dentine, suggesting T cells may inhibit osteoclast formation. In a coculture of T cells and monocytes, which were isolated from PBMC, T cells inhibited the osteoclast generation from monocytes, as determined by tartrate-resistant acid phosphatase (TRAP) staining and a pit assay using dentine. This inhibition of osteoclast generation by T cells was also observed in a culture of the
parathyroid hormone
-stimulated SaOS4/3 osteoblast cell line and monocytes. The culture in Transwell plates revealed that the cell-to-cell interaction was not required for the inhibition, suggesting that T-cell cytokines may be responsible for the inhibition. Among inhibitory T-cell cytokines on osteoclastogenesis,
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) and interferon-gamma (IFN-gamma) were actively produced by CD4 T cells but not CD8 T cells in the coculture of T cells with monocytes, and the neutralizing antibodies to these cytokines partially rescued the T-cell-induced inhibition of osteoclast formation. Although CsA did not affect RANKL-induced osteoclast generation in the culture of monocytes alone, it completely rescued the T-cell-induced inhibition of osteoclast formation and strongly inhibited the production of
GM-CSF
and IFN-gamma. Thus, we demonstrate that resting T cells negatively regulate the osteoclast generation via production of
GM-CSF
and IFN-gamma by CD4 T cells and that CsA stimulates the osteoclast generation through the inhibition of the production of these cytokines. These findings provide new insight into therapeutic strategies for immunosuppression-induced bone loss in transplant and other diseases.
...
PMID:Resting T cells negatively regulate osteoclast generation from peripheral blood monocytes. 1455 77
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