Showing papers by "Richard Bucala published in 1995"

MIF as a glucocorticoid-induced modulator of cytokine production

Abstract: Glucocorticoid hormones are important for vital functions and act to modulate inflammatory and immune responses. Yet, in contrast to other hormonal systems, no endogenous mediators have been identified that can directly counter-regulate their potent anti-inflammatory and immunosuppressive properties. Recent investigations of the protein macrophage migration inhibitory factor (MIF), which was discovered originally to be a T-lymphocyte-derived factor, have established it to be a pro-inflammatory pituitary and macrophage cytokine and a critical mediator of septic shock. Here we report the unexpected finding that low concentrations of glucocorticoids induce rather than inhibit MIF production from macrophages. MIF then acts to override glucocorticoid-mediated inhibition of cytokine secretion by lipopolysaccharide (LPS)-stimulated monocytes and to overcome glucocorticoid protection against lethal endotoxaemia. These observations identify a unique counter-regulatory system that functions to control inflammatory and immune responses.

Formation of immunochemical advanced glycosylation end products precedes and correlates with early manifestations of renal and retinal disease in diabetes.

Abstract: Elevated levels of advanced glycosylation end products (AGEs) have been found in multiple tissues in association with diabetic vascular complications and during the microalbuminuric phase of diabetic nephropathy. In this study, we have used an AGE-specific enzyme-linked immunosorbent assay (ELISA) to measure skin AGEs to determine whether elevated levels can be detected before the onset of overt microangiopathy. Subjects with type I diabetes ( n = 48) were graded for the degree of nephropathy (normal [23], microalbuminuria [12], or macroalbuminuria [12]) and retinopathy (none [13], background [20], or proliferative [15]). Subgroups with a premicroalbuminuric phase of albumin excretion (≤28 mg/24 h, n = 27) or with the earliest stages of retinopathy ( n = 27) were identified. A significant increase in tissue AGEs was found as urinary albumin increased during the premicroalbuminuric phase of nephropathy even when the data were adjusted for age and duration of diabetes ( P = 0.005). Immunoreactive AGEs also increased as normal renal status advanced to microalbuminuria and macroalbuminuria ( P = 0.0001 across groups). Significant elevation of AGEs was also found in association with the earliest stages of clinically evident retinopathy (early background versus minimal grades). In addition, higher AGE levels were found in subjects with proliferative retinopathy when compared with those with less severe retinopathy ( P

Localization of Macrophage Migration Inhibitory Factor (MIF) to Secretory Granules within the Corticotrophic and Thyrotrophic Cells of the Pituitary Gland

Abstract: Macrophage migration inhibitory factor (MIF) was one of the first lymphokine activities to be discovered and was described almost 30 years ago to be a soluble factor(s) produced by activated T lymphocytes In more recent studies, MIF has been “rediscovered” to be an abundant, pre-formed constituent of the anterior pituitary gland and the macrophage, and to be a critical component in the host response to septic shock Pituitary-derived MIF enters the circulation after infectious or stressful stimuli and appears to act to counterregulate glucocorticoid suppression of cytokine production Immunoelectron microscopy utilizing a combination of anti-MIF and anti-pituitary hormone-specific antibodies was used to study the ultrastructural localization of MIF within the anterior pituitary gland Pituitaries were obtained from resting, unstimulated mice and from mice 16 hr after endotoxin administration The release of MIF also was investigated in vitro by examining the effect of corticotropin-releasing hormone (CRH) on the AtT-20, corticotrophic cell line MIF localizes to granules present exclusively in ACTH and TSH secreting cells Within each cell type, a subset of granules was found to contain both MIF and ACTH, or MIF and TSH The pituitary content of MIF-containing granules decreased significantly after experimentally induced endotoxemia In seven pituitaries examined 16 hr after LPS injection, the number of MIF-positive granules diminished by 38% in corticotrophic cells and by 48% in thyrotrophic cells when compared with controls (p < 005) CRH was observed to be a potent MIF secretagogue in vitro, inducing the release of MIF from corticotrophic cells at concentrations lower than that required for ACTH release These data provide ultrastructural information that identify MIF to be a novel anterior pituitary hormone, support earlier studies showing a time-dependent release of pituitary MIF during endotoxemia, and suggest an important, systemic role for MIF in the stress response to infection and other stimuli

Identification of N2-(1-carboxyethyl)guanine (CEG) as a guanine advanced glycosylation end product.

Abstract: Reducing sugars such as glucose react nonenzymatically with protein amino groups to initiate a posttranslational modification process known as advanced glycosylation. Nucleotide bases also participate in advanced glycosylation reactions, producing DNA-linked advanced glycosylation endproducts (AGEs) that cause mutations and DNA transposition. Although several protein-derived AGEs have been isolated and structurally characterized, AGE-modified nucleotides have not yet been reported. We systematically examined the reactivities of the model nucleotide bases 9-methylguanine (9-mG), 9-methyladenine (9-mA), and 1-methylcytosine (1-mC) toward glucose and several glucose-derived reactants. In "fast" reactions performed at refluxing temperature and physiological pH, 1 equiv of nucleotide base was reacted with 10 equiv of D-glucose, D-glucose 6-phosphate (G-6-P), D-glucose 6-phosphate/lysine (G-6-P/Lys), the Schiff base 1-n-propylamino-N-D-glucoside (SB), or the Amadori product 1-n-propylamino-N-D-fructose (AP). In every reaction involving 9-mG, N2-(1-carboxyethyl)-9-methylguanine (CEmG) was a major product which was produced. N2-(1-carboxyethyl)-9-methylguanine also formed from 9-mG and AP in long-term incubations performed at 37 degrees C. Direct treatment of 9-mG with methylglyoxal (MG), a Maillard reaction propagator that forms from the decomposition of AP, also produced CEmG in high yield. N2-(1-Carboxyethyl)-9-methylguanine appears to result from the nucleophilic addition of the primary amino group of guanine to the ketone group of MG followed by an intramolecular rearrangement. Methylglyoxal is a known prokaryotic mutagen and was shown additionally to be mutagenic in a eukaryotic shuttle vector assay system.(ABSTRACT TRUNCATED AT 250 WORDS)

An inhibitor of macrophage arginine transport and nitric oxide production (CNI-1493) prevents acute inflammation and endotoxin lethality.

Abstract: Nitric oxide (NO), a small effector molecule produced enzymatically from L-arginine by nitric oxide synthase (NOS), is a mediator not only of important homeostatic mechanisms (e.g., blood vessel tone and tissue perfusion), but also of key aspects of local and systemic inflammatory responses. Previous efforts to develop inhibitors of NOS to protect against NO-mediated tissue damage in endotoxin shock have been unsuccessful, largely because such competitive NOS antagonists interfere with critical vasoregulatory NO production in blood vessels and decrease survival in endotoxemic animals. Accordingly, we sought to develop a pharmaceutical approach to selectively inhibit NO production in macrophages while sparing NO responses in blood vessels. The processes of cytokine-inducible L-arginine transport and NO production were studied in the murine macrophage-like cell line (RAW 264.7). A series of multivalent guanylhydrazones were synthesized to inhibit cytokine-inducible L-arginine transport. One such compound (CNI-1493) was studied further in animal models of endothelial-derived relaxing factor (EDRF) activity, carrageenan inflammation, and lethal lipopolysaccharide (LPS) challenge. Upon activation with cytokines, macrophages increase transport of L-arginine to support the production of NO by NOS. Since endothelial cells do not require this additional arginine transport to produce NO, we reasoned that a competitive inhibitor of cytokine-inducible L-arginine transport would not inhibit EDRF activity in blood vessels, and thus might be effectively employed against endotoxic shock. CNI-1493, a tetravalent guanylhydrazone, proved to be a selective inhibitor of cytokine-inducible arginine transport and NO production, but did not inhibit EDRF activity. In mice, CNI-1493 prevented the development of carrageenan-induced footpad inflammation, and conferred protection against lethal LPS challenge. A selective inhibitor of cytokine-inducible L-arginine transport that does not inhibit vascular EDRF responses is effective against endotoxin lethality and significantly reduces inflammatory responses.

Cloning and characterization of the gene for mouse macrophage migration inhibitory factor (mif)

Abstract: An emerging body of data indicates that the protein mediator described originally as macrophage migration inhibitory factor (MIF) exerts a central and wide ranging role in host inflammatory responses. MIF is a major constituent of corticotrophic cells within the anterior pituitary gland and is secreted into the circulation in a hormone-like fashion. MIF also exists performed in monocytes/macrophages and is a pivotal mediator in the host response to endotoxic shock. To gain further insight into the biologic expression of this protein that encompasses components of both the immune and the endocrine systems, we have cloned the mouse MIF gene and identified potential regulatory sequences present within the 5'-proximal promoter region. The gene for mouse MIF is located on chromosome 10, spans approximately 1 kb, and shares a high degree of structural homology with its human counterpart. Of note, the consensus enhancer/promoter motifs identified include both inflammatory/growth factor-related elements and sites associated with the genes for certain peptide hormones. We also report the structures of two MIF pseudogenes that account for early observations suggesting that mouse MIF is encoded by a highly homologous multigene family.

A Role for DNA Mutations in Diabetes-Associated Teratogenesis in Transgenic Embryos

Abstract: Congenital malformations are the leading cause of death in infants of insulin-dependent diabetic mothers. Although there are data to suggest that hyperglycemia itself is teratogenic, few mechanisms have been proposed to explain diabetic embryopathy. To address the possibility that DNA mutations play a role in the fetal malformations associated with diabetes, we developed a transgenic mouse model system to measure the mutation frequency of a neutral target gene, lacI, during embryonic development in a maternal hyperglycemic environment. Despite the short 21-day gestational period of the mouse, we observed a twofold increase in the mutant frequency of the lacI transgene in fetuses that developed in a mild diabetic environment (blood glucose > 8.3 mmol/l) compared with those that developed under normoglycemic conditions (blood glucose < 8.3 mmol/l). These data provide the first direct evidence of the genotoxic effect of diabetes in vivo and suggest a mechanism for the teratogenicity of the maternal diabetic environment.

Combination method for treating diseases caused by cytokine-mediated toxicity

Abstract: There is disclosed a method for treating an individual having a disease caused by cytokine-mediated toxicity comprising administering to the individual an effective amount of (a) an antibody that binds to an MIF polypeptide, wherein the MIF polypeptide has a molecular weight of about 12.5 kDa in combination with (b) anti-TNFα, anti-IL1, anti-IFN-γ, IL-1RA, a steroid, a glucocorticoid, or IL-10.

Immunochemical detection of in vivo advanced glycosylation endproducts

Abstract: The circulating advanced glycosylation endproducts Hb-AGE, serum AGE-peptides and urinary AGE-peptides are disclosed as long term markers of diseases and dysfunctions having as a characteristic the presence of a measurable difference in AGE concentration. Diagnostic and therapeutic protocols taking advantage of the characteristics of these AGEs are disclosed. Antibodies which recognize and bind to in vivo-derived advanced glycosylation endproducts are also disclosed. Methods of using these antibodies as well as pharmaceutical compositions are also disclosed, along with numerous diagnostic applications, including methods for the measurement of the presence and amount of advanced glycosylation endproducts in both plants and animals, including humans, as well as in cultivated and systhesized protein material for therapeutic use.

Advanced glycosylation endproducts in diabetic renal disease : clinical measurement, pathophysiological significance, and prospects for pharmacological inhibition

Abstract: Glucose reacts nonenzymatically with amino groups to produce a class of stable, crosslinking moieties termed advanced glycosylation endproducts (AGEs). These products act to increase vascular permeability, enhance subintimal protein and lipoprotein deposition, inactivate nitric oxide, and exert a number of toxic effects on endothelial cells. Loss of normal renal function has been found recently to cause a marked increase in the circulating levels of plasma AGEs, suggesting that these moieties may comprise one component of the so-called uremic ‘middle molecules’. AGEs also form on the lipid and the protein components of LDL, forming a modified form of LDL (AGE-LDL) which is not taken up by tissue LDL receptors. Aminoguanidine offers a specific therapeutic modality for inhibiting advanced glycosylation in vivo and has been observed recently to reduce both hemoglobin-AGE and circulating LDL levels.

Composition containing anti-MIF antibody

Abstract: The present invention relates to compositions and methods for inhibiting the release and/or biological activity of migration inhibitory factor (MIF). In particular, the invention relates to the uses of such compositions and methods for the treatment of various conditions involving cytokine-mediated toxicity, which include, but are not limited to shock, inflammation, graft versus host disease, and/or autoimmune diseases.

Antibodies to in vivo advanced glycosylation endproducts

Abstract: The circulating advanced glycosylation endproducts Hb-AGE, serum AGE-peptides and urinary AGE-peptides are disclosed as long term markers of diseases and dysfunctions having as a characteristic the presence of a measurable difference in AGE concentration. Diagnostic and therapeutic protocols taking advantage of the characteristics of these AGEs are disclosed. Antibodies which recognize and bind to in vivo-derived advanced glycosylation endproducts are also disclosed. Methods of using these antibodies as well as pharmaceutical compositions are also disclosed, along with numerous diagnostic applications, including methods for the measurement of the presence and amount of advanced glycosylation endproducts in both plants and animals, including humans, as well as in cultivated and systhesized protein material for therapeutic use.

Diagnostic assays for MIF

Abstract: The present invention relates to compositions and methods for inhibiting the release and/or biological activity of migration inhibitory factor (MIF). In particular, the invention relates to the uses of such compositions and methods for the treatment of various conditions involving cytokine-mediated toxicity, which include, but are not limited to shock, inflammation, graft versus host disease, and/or autoimmune diseases.