Interleukin-1β in human colostrum

The two forms of interleukin-1, IL-1α and IL-1β respectively, and tumour necrosis factor (TNF) are polypeptides sharing different biological activities which are often associated with host defence mechanisms. Because of the well-recognized benefits of breast feeding for newborns, colostrum from 9 healthy lactating women was analysed for the presence of these 3 cytokines. Specific radioimmunoassay revealed that colostrum contains a significant amount of IL-1β (mean ± SEM values of 1,130 ± 259 pg/ml). The concentrations of IL-1α and TNF were negligible.Colostral leukocytes are able to produce IL-1 since high activity was found after stimulation with Staphylococcus epidermidis. In addition, these cells produced IL-1 spontaneously in vitro, in contrast to resting maternal blood monocytes. As IL-1 increases resistance to infection, the presence of this cytokine represent a beneficial aspect of breast feeding.     

Estimation of TGF-β1 genotypes in Egyptian smokers; association with FEV1 in COPD patients

Introduction

TGF-β1 is a cytokine with many different effects on cell proliferation, differentiation and inflammation and can protect against the development of COPD. This work aims to study the association between COPD and the TGF-β1 gene genotypes.

Material and methods

The study included 70 males: 25 smokers with COPD, 25 resistant smokers, and 20 normal non-smokers as the control. They were subjected to spirometry pre- and post-bronchodilator (FEV₁, FEV₁/FVC), estimation of serum level of TGF-β1 gene by PCR and RFLP.

Results

The percent of Pro-Leu was 28% in the COPD group, 84% in the resistant smokers group and 85% in the control group. There was a highly significant statistical difference in FEV₁% of predicted associated with the distribution of TGF-β1 gene genotypes: 56.9 ±8.4% with Pro-Leu genotype and 35.5 ±8.8% with Leu-Leu genotype in COPD patients, 93.2 ±6.2% with Pro-Leu genotype and 86.7 ±0.9% with Leu-Leu genotype in the resistant smokers group.

Conclusions

The Pro-allele genotype is associated with increased production of TGF-β1, which has a protective role against the development of COPD and is important in preserving the decline of FEV₁ in COPD patients.     

HLA-DQA1 Polymorphism in Idiopathic Dilated Cardiomyopathy

Idiopathic dilated cardiomyopathy (IDC) is a disease ofunknown etiology, for which immune abnormalities, possi bly related to viral infections, are widely suspected butunproven. Many abnormalities in humoral and cellular re sponses have been reported, including the previous sero logic studies of correlation between human leukocyte anti gen DR4 and IDC[1]. However there was little informa tion on the relation between antigens at the DQA1 loci ofthe HLA system and idiopathic dilated c…     

Changes of immunoreactivity in α1-antitrypsin in patients with autoimmune diseases

Recent studies from this laboratory have shown that a monoclonal antibody prepared against a specific epitope on ₁-antitrypsin is a valuable diagnostic marker for autoimmune conditions. In the present study we have further characterized this monoclonal antibody and reassessed its diagnostic value in screening samples from patients with various autoimmune conditions. ₁-Antitrypsin was micropurified from patients with selected autoimmune conditions and from normal donors. The purified ₁-antitrypsin isolated. from patients with autoimmune conditions and normal donors was deglycosylated losing both a mixture of exoglycosidases and endoglycosidase F. The immunoreactivity of the native and deglycosylated ₁-antitrypsin was examined using both a monoclonal antibody and a polyclonal antibody in enzyme linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), respectively. It was noted that ₁-antitrypsin isolated from patients with autoimmune diseases generated a displacement curve dissimilar to ₁-antitrypsin purified from normal donors or ₁ antitrypsin from patients with autoimmune diseases subjected to deglycosylation when these samples were examined by ELISA using the monoclonal antibody. However, when the polyclonal antibody was used for these studies, no difference was found between the native and deglycosylated ga₁,-antitrypsin suggesting that the monoclonal antibody recognized an epitope not detectable by the polyclonal antibody. We have also assessed the diagnostic usefulness of this monoclonal antibody using a battery of 530 serum samples obtained from patients with different autoimmune diseases and compared to normal human serum (NHS,N–66); these include: systemic lupus erythematosus (SLE,N=149), rheumatoid arthritis (RA,N=64), renal diseases (NP,N=33), liver diseases (HP,N=33), mixed connective tissue disease (MCTD,N = 12), diabetes (DB,N=40), SjÖgren's syndrome (SS,N = 41), polymyositis (PM,N=20), scleroderma (SCL,N=20), Alzheimer's disease (AZ,N=11), and patients with elevated levels of carcinoembryonic antigen (CEA,N=41). The results of this study demonstrated that this monoclonal antibody is positively correlated with SLE and SS. The significance of the monoclonal antibody in connection with the pathogenesis of autoimmune diseases was discussed.     

Differential susceptibility to lethal endotoxaemia in mice deficient in IL-1α, IL-1β or IL-1 receptor type I

Joosten LAB, van de Veerdonk F, Vonk AG, Boerman OC, Keuter M, Fantuzzi G, Verschueren I, van der Poll T, Dinarello CA, Kullberg BJ, Van der Meer JWM, Netea MG. Differential susceptibility to lethal endotoxaemia in mice deficient in IL‐1α, IL‐1β or IL‐1 receptor type I. APMIS 2010; 118: 1000–7. The role of intereukin‐1 (IL‐1) in mortality caused by endotoxaemia remains controversial. While IL‐1 receptor antagonist (IL‐1Ra) protects mice from lethal endotoxaemia, mice deficient in IL‐1β (IL‐1β^{? /?}) display normal susceptibility to lipopolysaccharide (LPS). The aim of this study was to identify the source of these discrepancies. Mice deficient in IL‐1α, IL‐1β or IL‐1R type I were injected intraperitoneally with Escherichia coli or Salmonella typhimurium LPS. Survival of the mice was examined and compared with C57/Bl6 wild‐type mice. In addition, serum cytokine concentrations were determined after LPS challenge and in vitro cytokine production by peritoneal macrophages was analysed. Clearance of radioactive IL‐1α was examined in IL‐1α^?/? and wild‐type mice. IL‐1β^?/? mice were normally susceptible to endotoxaemia and cytokine production did not differ from that in control mice. Surprisingly, LPS mortality in IL‐1α^?/? mice was significantly greater than that in control mice, accompanied by higher interferon‐γ release. These effects were mediated by a distorted homeostasis of IL‐1RI receptors, as shown by a strongly delayed clearance of IL‐1α. In contrast to the IL‐1α^?/? and IL‐1β^?/? mice, IL‐1RI^?/? mice were completely resistant to high doses of LPS. In conclusion, IL‐1RI‐mediated signals are crucial in mediating mortality occurring as a result of lethal endotoxaemia. Investigation of IL‐1‐mediated pathways in IL‐1 knock‐out mice is complicated by a distorted homeostasis of IL‐1Rs.     

Collagen XIII Induced in Vascular Endothelium Mediates α1β1 Integrin-Dependent Transmigration of Monocytes in Renal Fibrosis

Alport syndrome is a common hereditary basement membrane disorder caused by mutations in the collagen IV α3, α4, or α5 genes that results in progressive glomerular and interstitial renal disease. Interstitial monocytes that accumulate in the renal cortex from Alport mice are immunopositive for integrin α1β1, while only a small fraction of circulating monocytes are immunopositive for this integrin. We surmised that such a disparity might be due to the selective recruitment of α1β1-positive monocytes. In this study, we report the identification of collagen XIII as a ligand that facilitates this selective recruitment of α1β1 integrin-positive monocytes. Collagen XIII is absent in the vascular endothelium from normal renal cortex and abundant in Alport renal cortex. Neutralizing antibodies against the binding site in collagen XIII for α1β1 integrin selectively block VLA1-positive monocyte migration in transwell assays. Injection of these antibodies into Alport mice slows monocyte recruitment and protects against renal fibrosis. Thus, the induction of collagen XIII in endothelial cells of Alport kidneys mediates the selective recruitment of α1β1 integrin-positive monocytes and may potentially serve as a therapeutic target for inflammatory diseases in which lymphocyte/monocyte recruitment involves the interaction with α1β1 integrin.Alport syndrome is a relatively common (1 in 5000) hereditary basement membrane disorder caused by mutations in the collagen IV α3, α4, or α5 genes.^1,2,3 The disease manifests with progressive renal disease associated with hearing loss and retinal flecks. There are several models for Alport’s Syndrome including a collagen IV α3 knockout mouse.^4,5 In the 129 Sv Alport mouse model, animals develop glomerular and interstitial fibrosis followed by end stage renal failure between 8 and 9 weeks of age. Increased extracellular matrix deposition, mesangial matrix expansion, impaired glomerular filtration, scarring and tubular atrophy observed in this model correlate with Alport’s syndrome pathogenesis reported in humans. In this model two biochemical pathways are known to contribute to disease progression. The first pathway requires transforming growth factor-β, while the second is α1-integrin dependent.⁶Monocytes express transforming growth factor-β which facilitates myofibroblast accumulation and matrix deposition in Alport mice. Monocytes also express matrix metalloproteinases and associated proteins capable of degrading tubular basement membranes and promoting tubular epithelial cell death.⁷ These findings suggest that monocytes are of principal importance in promoting scarring and tubular atrophy in chronic renal fibrosis. This connection has been corroborated in other models of renal fibrosis.^8,9 Thus the cellular mechanisms that facilitate transmigration and proliferation of interstitial monocytes are important factors in promoting the progression of interstitial disease.In an earlier report, we showed that nearly all of the monocytes in Alport kidneys express α1β1 integrin.¹⁰ We also have shown that integrin α1-null Alport mice live nearly twice as long as Alport mice, an observation that correlates well with a marked reduction in interstitial monocyte accumulation.^6,10 Alpha1beta1 integrin (also known as VLA-1, or very late antigen 1) mediates collagen dependent cell proliferation and adhesion.^11,12 However, a role for α1β1 integrin in transmigration of inflammatory cells across the microvascular barrier into the interstitial spaces has not been directly demonstrated.Monocyte and lymphocyte transmigration into the interstitial space is a principal event underlying both acute and chronic inflammatory response mechanisms.¹³ Many aspects of the cellular events underlying the initiation and progression of monocyte efflux have been elaborated in recent years, as these pathways are central to pathobiology of many inflammatory diseases. The initiation of the inflammatory response involves cellular expression of chemokines and inflammatory cytokines, which have profound effects on adjacent cells. The vascular and capillary endothelial cells respond by up-regulating expression of selectins and intercellular adhesion molecules.^14,15 The selectins loosely adhere to lymphocytes and monocytes resulting in a “slow rolling” effect that can be visualized directly using intravital microscopy.¹⁶ Intercellular adhesion molecules and related inducible endothelial cell surface ligands provide the substrate for firm adhesion through interactions with the integrin family of heterodimeric receptors on the surface of the monocytes.¹³ Firm adhesion results in monocyte activation, inducing the expression of proteins needed to degrade the capillary basal lamina, allowing invasion into the interstitial space.^17,18 The activated monocyte produces additional chemokines and cytokines, which further accelerate monocyte recruitment and the progression of the inflammatory response.Research aimed at defining the specific cellular mechanisms underlying monocyte and lymphocyte recruitment has been prolific. The discovery of integrins, a vastly important family of cell surface receptors that mediate adhesion, cell migration and signal transduction, resulted from studies aiming to identify the adhesion receptors on peripheral blood monocytes and lymphocytes, as well as their cognate ligands on activated vascular endothelium.¹⁹ Monoclonal antibodies that block the interaction of these cells with endothelial cell surface receptors have emerged as potentially effective therapeutic approaches for treating chronic inflammatory diseases such as multiple scleroses and psoriasis. A large number of such agents are currently in various stages of preclinical and clinical trials.^20,21The α1-integrin heterodimerizes only with β1-integrin. The heterodimer is found in the plasma membrane of a variety of cell types, and is widely viewed as a collagen binding integrin, although binding to other matrix molecules has been demonstrated.^22,23 We used a monocyte-specific cell trafficking assay to determine whether selective transmigration of α1β1 integrin-positive monocytes contributes to the accumulation of these cells in the Alport mouse kidneys. Our results suggest that α1β1 integrin-positive monocytes are indeed selectively recruited to the interstitium and the rate of transendothelial migration increases over time. We used Phage display and biopanning strategies to identify the α1β1 integrin ligand involved in selective recruitment as collagen XIII (a membrane bound collagen). Collagen XIII mRNA and protein are induced in the vascular endothelium of Alport mice. Monoclonal antibodies raised against the binding site on collagen XIII for α1β1 integrin block monocyte adhesion to collagen XIII on embryonic fibroblasts, and when administered systemically to Alport mice, markedly decrease monocyte efflux into the tubulointerstitial space. Matrix accumulation and tubulointerstitial damage are also markedly reduced. Collectively, these data suggest that collagen XIII is an inducible endothelial cell ligand for α1β1 integrin on peripheral blood monocytes, and mediates monocyte adhesion and transmigration. Blocking collagen XIII may provide a novel therapeutic target for chronic inflammatory diseases where α1β1 integrin-positive interstitial monocytes (or T-cells) play a role.     

Integrin α1/β1 and α2/β1 as a receptor for IgA1 in human glomerular mesangial cells in IgA nephropathy

IgA nephropathy (IgAN) is characterized by mesangial deposition of IgA1 and galactose-deficient IgA1 is expected to play a pathogenic role. However, the identity of the receptor for IgA1 is still controversial. Hence, the aim of this study was to explore the receptor for galactose-deficient IgA1. Human monoclonal IgA1 was treated with exoglycosidase and FITC-conjugated control, asialo- and agalactosyl-IgA1 was used as a probe to detect the receptor in cultured human mesangial cells. Tumor necrosis factor-α or transforming growth factor-β1 treatment accelerated IgA1-binding on mesangial cells, and these effects were diminished by the addition of dexamethasone, whereas these changes were not dependent on galactose-deficiency of IgA1. According to comprehensive gene expression analysis, we focused on integrin β1. Pre-treatment by Mn(2+), which activates integrin by changing its structure, enhanced the binding of IgA1 in cultured mesangial cells. Furthermore, pre-incubation with collagens specifically enhanced binding of IgA1 in the cultured human mesangial cells without activation by Mn(2+). Collagen type IV distributed in the mesangial region of the glomeruli as well as Bowman's capsule and tubular basal membrane in IgAN patients, and the IgA1 with collagen type IV induced proliferative signals on mesangial cells by phosphorylating extracellular signal-regulated kinase more effectively than the IgA1 alone. Immunoprecipitation assay revealed the binding of IgA1 and integrin α1/β1 and α2/β1 heterodimer and down-regulation of integrin α1, α2 and β1 expression in human mesangial cells induced by each specific small interfering RNA diminished the ability to bind IgA1 probe. Integrin α1/β1 and α2/β1 would be a candidate receptor for IgA1.     

Lung inflammation induces IL-1β expression in hypoglossal neurons in rat brainstem

Perinatal inflammation is associated with respiratory morbidity. Immune modulation of brainstem respiratory control centers may provide a link for this pathobiology. We exposed 11-day old rats to intratracheal lipopolysaccharide (LPS, 0.5 μg/g) to test the hypothesis that intrapulmonary inflammation increases expression of the proinflammatory cytokine IL-1β within respiratory-related brainstem regions. Intratracheal LPS resulted in a 32% increase in IL-1β protein expression in the medulla oblongata. In situ hybridization showed increased intensity of IL-1β mRNA but no change in neuronal numbers. Co-localization experiments showed that hypoglossal neurons express IL-1β mRNA and immunostaining showed a 43% increase in IL-1β protein-expressing cells after LPS exposure. LPS treatment also significantly increased microglial cell numbers though they did not express IL-1β mRNA. LPS-induced brainstem expression of neuronal IL-1β mRNA and protein may have implications for our understanding of the vulnerability of neonatal respiratory control in response to a peripheral proinflammatory stimulus.     

Pathogenic role of HMGB1 in SARS?

High mobility group box 1 protein (HMGB1) is released by necrotic cells or activated macrophages/monocytes, and functions as a late mediator of lethal systemic and local pulmonary inflammation. Passive immunization with anti-HMGB1 antibodies confers significant protection against lethal endotoxemia, sepsis, and acute lung injury, even when antibodies are administered after the onset of these diseases. In light of observations that three Chinese herbal formulations recommended for treatment of severe acute respiratory syndrome (SARS) specifically inhibited the release of HMGB1 from innate immune cells, we hypothesize that HMGB1 might occupy a pathogenic role in SARS by mediating an injurious pulmonary inflammatory response.     

Alterations in presenilin 1 processing by amyloid-β peptide in the rat retina

Accumulating evidence indicates that mutations in the presenilin 1 (PS1) gene are responsible for most cases of familial Alzheimer’s disease (AD). Although its biological functions are not yet fully understood, it appears that PS1 plays a role in the processing and trafficking of the amyloid precursor protein (APP). However, little is known about factors that are involved in regulating the metabolism of PS1 especially in relation to AD pathology. In this study, we have examined the effect of optic nerve crush, intravitreal injection of the inflammatory agent lipopolysaccharide (LPS) or injection of amyloid β_1-42 (Aβ_1-42) on the expression and processing of PS1 in the rat retina. We found that 48 h after injection of Aβ_1-42 there was a dramatic alteration in the banding pattern of PS1 on Western blots, as indicated by marked changes in the levels of expression of some of its C- and N-terminal fragments in retinal homogenates. These results suggest an Aβ_1-42-induced potentiation of a non-specific stress-related but inflammation-independent alteration of processing of PS1 in this in vivo model.     

Knockdown of Sirt1 Gene in Mice Results in Lipid Accumulation in the Liver Mediated via PGC-1α-Induced Mitochondrial Dysfunction and Oxidative Stress

Bulletin of Experimental Biology and Medicine - The study demonstrated the crucial role of Sirt1 gene in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) related to the influence of...     

Involvement of IL-1β and IL-6 in antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in rats

Purpose: Evidence show that statins possess wide beneficial cardioprotective and anti-inflammatory effects; therefore, in the present experiment, we investigated the antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in isolated rat atria and the role of several inflammatory cytokines in this effect.

Materials and methods: Male rats were pretreated with either of atorvastatin (10?mg/kg) or vehicle, orally once daily for 6 weeks. After induction of anesthesia, we isolated the atria and after incubation with ouabain, time of onset of arrhythmia and asystole as well as atrial beating rate and contractile force were recorded. We also measured the atrial levels of IL-1β, IL-6, and TNF-α after the injection of ouabain to animals.

Results: Pretreatment with atorvastatin significantly delayed the onset of arrhythmia and asystole compared with vehicle-treated group (p?p?p?p?>?.05). Injection of ouabain elevated the atrial levels of IL-1β, IL-6, and TNF-α, while pretreatment of animals with atorvastatin could reverse the ouabain-induced increase in atrial IL-1β and IL-6 (p?p?Conclusions: It is concluded that observed antiarrhythmic effects of atorvastatin might be attributed to modulation of some inflammatory cytokines, at least IL-1β and IL-6.     

Selective down-regulation of aquaporin-1 in salivary glands in primary Sjögren's syndrome

Salivary and lacrimal gland secretions are reduced in primary Sj?gren's syndrome (pSS). Aquaporins (AQPs) are involved in transmembrane water transport, and different isoforms show specific cellular and subcellular distributions in salivary and lacrimal glands. Changes in expression of AQP molecules have therefore been suggested to contribute to the glandular dysfunction in pSS. AQP-5 is present in the apical membrane of acinar cells, where it mediates fluid outflow; however, we have recently shown that its expression is not altered in pSS. We therefore studied whether expression of other isoforms of AQP would be altered in pSS. Using high-resolution confocal microscopy, we determined the distribution of AQP-1 and AQP-3 in labial salivary gland biopsies from 11 patients with pSS and 9 healthy controls. AQP-1 is present in myoepithelial cells surrounding acini, and its expression in these cells was decreased by 38% in pSS glands. By contrast, expression of AQP-1 in endothelial cells of nonfenestrated capillaries was not altered in pSS. AQP-3 was expressed in the basolateral membrane of acinar epithelial cells, and its expression was not altered in disease. We therefore conclude that AQP-1 expression in myoepithelial cells is selectively down-regulated in pSS and that myoepithelial cell dysfunction may play a crucial role in the pathology of this disease.     

Tas1R1–Tas1R3 taste receptor variants in human fungiform papillae

Monosodium glutamate as well as metabotropic and ionotropic glutamate receptor agonists have been reported to be perceived as umami by humans. In spite of the fact that Tas1R1–Tas1R3 has been shown to mediate most of the glutamate taste sensation in mice other candidate receptors have been put forward for which a clear role in detection is still lacking. This work was aimed at investigating the molecular determinants underlying umami taste detection in humans. First, we show evidence supporting expression of Tas1R1 and Tas1R3 but not mGluRs in the fungiform papillae of several individuals. Next, we report a number of naturally occurring l-glutamate taste receptor variants and their frequency in a population of Caucasian subjects. Detailed analysis of 9 non-synonymous single nucleotide polymorphisms from three l-glutamate taste GPCR candidates uncovers receptor specific clusters such that all substitutions in Tas1R1 are located in the extracellular N-terminal ligand-binding domain while in Tas1R3 they mostly affect residues in the seven transmembrane-spanning core domain responsible for the interaction with antagonists and allosteric modulators. In mGluR1, nsSNPs identified are clustered in the intracellular C-terminal tail, which is thought to play a role in signaling. Taken together, these results suggest that Tas1R1–Tas1R3 receptor variants found in human fungiform papillae might contribute to inter-individual differences of sensitivity to l-glutamate.     

Changes in the expression of syndecan-1 in the colorectal adenoma–carcinoma sequence

 Syndecan-1, a transmembrane heparan sulphate proteoglycan (HSPG), functions as a matrix receptor on the basal surface of epithelial cells. It also co-localizes with E-cadherin at the lateral cell surface where its function is uncertain. Tumour development in the large bowel is associated with loss of normal epithelial adhesion and altered patterns of expression of cell adhesion molecules, possibly including syndecan-1. To evaluate changes in syndecan-1 expression during the development of colorectal neoplasia, 59 adenomas and 20 carcinomas arising from adenomas were investigated by immunohistochemistry. The staining intensity and distribution of syndecan-1 and E-cadherin in sequential sections was examined, semi-quantified and compared. Staining of syndecan-1 and E-cadherin was uniform in normal colorectal epithelial cells, and located at the basolateral surface. No significant change was seen in either molecule in mildly or moderately dysplastic adenomas. A significant reduction in expression of both syndecan-1 and E-cadherin was seen in severely dysplastic epithelium as compared to moderate dysplasia (P=0.001 and P=0.004 respectively). Similarly, there was a significant reduction of both molecules in carcinomas compared with associated adenomas (syndecan-1 P=0.00003; E-cadherin P=0.002). In both cases the loss of syndecan-1 expression was more striking than that of E-cadherin. Previous in vitro studies have shown that epithelial cells made deficient in syndecan-1 cease to express E-cadherin, suggesting a causal association. Our results support these findings and indicate that disruption of cell-matrix adhesion is critical in colorectal carcinogenesis, probably preceding changes in the purely homotypic cell-cell adhesion mediated by E-cadherin. Received: 11 May 1998 / Accepted: 14 September 1998