Immune modulation with interleukin-4 and interleukin-10 prevents crescent formation and glomerular injury in experimental glomerulonephritis

Crescentic glomerulonephritis (GN) demonstrates immunopathological features of a T helper (Th)1-directed delayed-type hypersensitivity (DTH) response. The capacity of Th2 cytokines to attenuate crescentic glomerular injury in this disease was examined by administering interleukin (IL)-4 and IL-10, singly and in combination. GN was induced by i.v. administration of sheep anti-mouse glomerular basement membrane (GBM) globulin to mice sensitized to sheep globulin 10 days earlier. Treatment (2.5 μg, i.p.) with IL-4, IL-10, or both IL-4 and IL-10 (IL-4+10), was started 1 h before sensitization and continued daily until the end of the study (10 days after administration of anti-GBM globulin). Control mice treated with PBS developed GN with glomerular accumulation of T cells and macrophages, crescents in 42.5 ± 4.5 % of glomeruli (normal 0 %), proteinuria (8.3 ± 0.9 mg/24 h, normal 0.74 ± 0.08 mg/24 h, p < 0.001) and renal impairment (creatinine clearance [cr/cl]: 93 ± 12 μ1/min, normal 193 ± 10 μ1/min, p<0.001). 1reatment with either IL-4, IL-10, or IL-4+10 prevented crescent formation (crescentic glomeruli: 0.8 ± 0.5, 1.2 ± 0.9, and 1.4 ± 1.0 %, respectively, all p<0.01 compared to control) and attenuated proteinuria (3.6 ± 1.0, 2.2 ± 0.5, and 2.9 ± 0.5 mg/24 h, respectively, all p<0.01 compared to control). IL-4+10 prevented development of renal impairment (cr/cl: 183 ± 22 μ1/min); IL-10 given alone limited the decline in renal function (cr/cl: 150 ± 20 μ1/min), but IL-4 alone did not provide any significant protection (cr/cl: 121 ± 17 μ1/min). All treatments markedly diminished glomerular T cell and macrophage accumulation, reduced interferon-γ production by splenic T cells, prevented cutaneous DTH to the disease-initiating antigen and reduced antigen-specific immunoglobulin of the IgG2a and IgG3 isotypes. These data demonstrate that crescentic GN and renal impairment can be prevented by administration of Th2 cytokines and that this effect is associated with attenuation of the Th1 response to the disease-initiating antigen.     

The cytoplasmic domain of tissue factor contributes to leukocyte recruitment and death in endotoxemia

Tissue factor (TF) is an integral membrane protein that binds factor VIIa and initiates coagulation. The extracellular domain of TF is responsible for its hemostatic function and by implication in the dysregulation of coagulation, which contributes to death in endotoxemia. The role of the cytoplasmic domain of tissue factor in endotoxemia was studied in mice, which lack the cytoplasmic domain of TF (TF(deltaCT/deltaCT)). These mice develop normally and have normal coagulant function. Following i.p injection with 0.5 mg of lipopolysaccharide (LPS), TF(deltaCT/deltaCT) mice showed significantly greater survival at 24 hours compared to the wt mice (TF(+/+)). The serum levels of TNF-alpha and IL-1beta were significantly lower at 1 hour after LPS injection and IL-6 levels were significantly lower at 24 hours in TF(deltaCT/deltaCT) mice compared to TF(+/+)mice. Neutrophil recruitment into the lung was also significantly reduced in TF(deltaCT/deltaCT) mice. Nuclear extracts from tissues of endotoxemic TF(deltaCT/deltaCT) mice also showed reduced NFkappaB activation. LPS induced leukocyte rolling, adhesion, and transmigration in post-capillary venules assessed by intravital microscopy was also significantly reduced in TF(deltaCT/deltaCT) mice. These results indicate that deletion of the cytoplasmic domain of TF impairs the recruitment and activation of leukocytes and increases survival following endotoxin challenge.     

Tissue factor pathway inhibitor expression in human crescentic glomerulonephritis

BACKGROUND: Tissue factor (TF) pathway inhibitor (TFPI), the major endogenous inhibitor of extrinsic coagulation pathway activation, protects renal function in experimental crescentic glomerulonephritis (GN). Its glomerular expression and relationship to TF expression and fibrin deposition in human crescentic GN have not been reported. METHODS: Glomerular TFPI, TF, and fibrin-related antigen (FRA) expression were correlated in renal biopsies from 11 patients with crescentic GN. Biopsies from 11 patients with thin basement membrane disease and two normal kidneys were used as controls. RESULTS: TFPI was undetectable in control glomeruli but was detectable in interstitial microvessels. In crescentic biopsies, TFPI was detected in cellular crescents and was more prominent in fibrous/fibrocellular crescents, indicating a correlation with the chronicity of crescentic lesions. TFPI appeared to be associated with macrophages but not endothelial or epithelial cells. TFPI was generally undetectable in regions of the glomerular tuft with minimal damage. In contrast, TF and FRA were strongly expressed in regions of minimal injury, as well as in more advanced proliferative and necrotizing lesions. Despite prominent TF expression, FRA was less prominent in fibrous/fibrocellular crescents in which TFPI expression was maximal. CONCLUSIONS: These data suggest that TFPI is strongly expressed in the later stages of crescent formation and is inversely correlated with the presence of FRA in human crescentic GN. This late induction of TFPI may inhibit TF activity and favor reduced fibrin deposition in the chronic stages of crescent formation.     

Infants born to narcotic dependent mothers: Physical growth patterns in the first 12 months of life

Objectives: To describe the physical growth patterns of infants born to narcotic dependent mothers (INDM) over a 12 months period and, if possible, to relate the growth to drug taking patterns during pregnancy.
Methodology: The growth of a cohort of 43 INDM was measured during the first 12 months of life. Weight and length measurements were compared with percentile charts and converted to Z scores. Questionnaire data about drug taking practices, demographic variables and the neonatal period (including withdrawal scores) were obtained.
Results: Twenty-four (55.8%) of INDM had evidence of neonatal drug withdrawal requiring treatment with phenobarbitone. At birth, Z scores for weight and length indicated relative intrauterine growth retardation. By 12 months, there had been some catch up growth, but Z scores for weight and length were still below zero. Persistent weight retardation at 12 months was correlated with methadone dosage during pregnancy, but not the need for phenobarbitone therapy.
Conclusions: The growth patterns of INDM in the first 12 months of life indicated that at birth there was evidence of intrauterine growth retardation, but by 12 months the growth was little different from the rest of the community. There appears to be some influence of narcotic agents taken while pregnant on subsequent growth of INDM.     

Identification of differentially expressed genes in aflatoxin B1- treated cultured primary rat hepatocytes and Fischer 344 rats

Aflatoxin B1 (AFB1), a mutagen and hepatocarcinogen in rats and humans, is a contaminant of the human food supply, particularly in parts of Africa and Asia. AFB1-induced changes in gene expression may play a part in the development of the toxic, immunosuppressive and carcinogenic properties of this fungal metabolite. An understanding of the-role of AFB1 in modulating gene regulation should provide insight regarding mechanisms of AFB1-induced carcinogenesis. We used three PCR- based subtractive techniques to identify AFB1-responsive genes in cultured primary rat hepatocyte RNA: differential display PCR (DD-PCR), representational difference analysis (RDA) and suppression subtractive hybridization (SSH). Each of the three techniques identified AFB1- responsive genes, although no individual cDNA was isolated by more than one technique. Nine cDNAs isolated using DD-PCR, RDA or SSH were found to represent eight genes that are differentially expressed as a result of AFB1 exposure. Genes whose mRNA levels were increased in cultured primary rat hepatocytes after AFB1 treatment were corticosteroid binding globulin (CBG), cytochrome P450 4F1 (CYP4F1), alpha-2 microglobulin, C4b-binding protein (C4BP), serum amyloid A-2 and glutathione S-transferase Yb2 (GST). Transferrin and a small CYP3A-like cDNA had reduced mRNA levels after AFB1 exposure. Full-length CYP3A mRNA levels were increased. When liver RNA from AFB1-treated male F344 rats was evaluated for transferrin, CBG, GST, CYP3A and CYP4F1 expression, a decrease in transferrin mRNA and an increase in CBG, GST, CYP3A and CYP4F1 mRNA levels was also seen. Analysis of the potential function of these genes in maintaining cellular homeostasis suggests that their differential expression could contribute to the toxicity associated with AFB1 exposure.