Altered expression of immune-associated genes in first-trimester human decidua of pregnancies later complicated with hypertension or foetal growth restriction.

During pregnancy the maternal immune system has to coordinate uterine spiral-artery remodelling, trophoblast invasion, and acceptance of the semi-allogenic fetus simultaneously. As dysregulation of the immune system is associated with adverse pregnancy outcomes, we analysed first-trimester deciduas of pregnancies for immune parameters in later complicated pregnancies. Higher IL6 and macrophage mRNA expression, and lower ratios of regulatory macrophages were found in first-trimester deciduas of pregnancies later complicated with pregnancy-induced hypertension. Lower Gata3 (Th2) mRNA expression was found in deciduas of pregnancies with later foetal growth restriction. Our results suggest that adverse pregnancy outcomes are associated with immunological disturbances in first-trimester deciduas.

ADAM19 expression in human nephrogenesis and renal disease: associations with clinical and structural deterioration.

ADAM19, an enzyme from the ADAM (a disintegrin and metalloproteinase) family, is involved in various cell-cell and cell-matrix interactions. It can cleave epidermal growth factor (EGF)-like growth factors, such as heparin-binding (HB)-EGF and neuregulin (NRG), from the cell membrane. ADAM-mediated EGF receptor activation is crucial in the development of renal pathology. Based on these data, we studied ADAM19 in human nephrogenesis and renal disease. We collected 20 fetal kidneys and 56 biopsies from patients with various renal diseases. The unaffected part of kidneys from eight patients with renal cell carcinoma served as control. RNA in situ hybridization revealed widespread ADAM19 mRNA expression in the nephrogenic zone of human fetal kidneys. Normal human kidneys showed constitutive ADAM19 expression in distal tubules and endothelial cells, whereas proximal tubules were negative. In renal disease, ADAM19 was de novo expressed in proximal tubules and glomerular mesangium and upregulated in distal tubules and endothelial cells. ADAM19 colocalized with tubular and interstitial NRG, however, not with HB-EGF. Independent of renal disorder, mesangial ADAM19 expression was associated with glomerular damage as assessed by mesangial matrix expansion, focal glomerulosclerosis, and glomerular macrophage influx (all P<0.001). ADAM19 in proximal tubules and in peritubular capillaries was associated with interstitial fibrosis (P<0.05). Finally, increasing tubular ADAM19 was associated with declining renal function (P<0.05). The abundant ADAM19 expression during nephrogenesis points to a role in growth promotion and regulation. The high ADAM19 expression in renal disease suggests involvement in profibrotic and proinflammatory processes leading to renal deterioration.

Upregulation of ADAM19 in chronic allograft nephropathy.

ADAM19 (a disintegrin and metalloproteinase 19) is involved in cell-cell and cell-matrix interactions and tumor necrosis factor (TNF)-alpha shedding. We studied ADAM19 in chronic allograft nephropathy (CAN) nephrectomies and in normal human kidneys. Reverse transcriptase (RT) PCR revealed an upregulation of ADAM19 mRNA in CAN when compared with control kidneys (p = 0.002). Using RNA in situ hybridization (ISH), we detected moderate ADAM19 mRNA expression in vascular smooth muscle cells (SMCs) and distal tubuli of control kidneys. In CAN, massive ADAM19 expression was detected in SMCs, distal tubuli, glomerular sclerotic lesions and inflammatory CD4+ cells. To determine whether ADAM19 is specifically related to CAN, we studied transplant biopsies with and without CAN, acute rejection and non-transplant-related kidney diseases: interstitial fibrosis (IF), interstitial atrophy, glomerular fibrosis and interstitial inflammation. In various renal structures, ADAM19 mRNA was significantly higher in CAN when compared with renal allografts without CAN or acute rejection. ADAM19 expression in renal endothelium was significantly higher in acute rejection when compared with renal allografts without CAN. When compared to CAN, ADAM19 was expressed to a similar extent in non-transplant-related interstitial and glomerular fibrosis, interstitial atrophy and inflammation. Although these observational data do not establish a cause and effect relationship, ADAM19 may have a modulatory role in the dysfunctional renal allograft state.

Bone mineral density in children, adolescents and adults with glycogen storage disease type Ia: a cross-sectional and longitudinal study.

The occurrence of (symptoms related to) osteopenia is a known complication in glycogen storage disease type Ia (GSD Ia) patients. However, only limited information is available about bone mineral density (BMD). Using dual energy x-ray absorptiometry, we studied both cross-sectional and longitudinal lumbar spine areal BMD (BMD(areal) in g/cm2), areal BMD corrected for delayed bone maturation (BMD(bone age) in g/cm2), and volumetric BMD (BMD(vol) in g/cm3). Prepubertal GSD Ia patients (n = 8) had normal BMD (median z-scores BMD(areal) -0.6, BMD(bone age) -0.5 and BMD(vol) -0.5), whereas adolescent patients (n = 12) and adult patients (n = 9) had significantly reduced BMD (BMD(areal) -2.3, BMD(bone age) -1.6, BMD(vol) -2.0, and BMD(areal) -1.9, BMD(vol) -1.5, respectively). Our longitudinal study, showing a stable BMD(areal) but a trend to a decrease in BMD(vol) in prepubertal patients during follow-up, did not clarify whether the difference in BMD between prepubertal and adolescent/adult patients reflects a diminished accretion of BMD during childhood or reflects historical differences in treatment. In adolescent and adult GSD Ia patients, BMD(areal) and BMD(vol) were reduced but stable during follow-up. Especially patients with delayed bone maturation were at risk for reduced BMD. No correlation between parameters of metabolic control and BMD could be detected. Daily calcium intake was within recommended allowances ranges. Abnormal biochemical results included hypomagnesaemia (29%), hypercalciuria (34%) and reduced tubular resorption of phosphate (21%). Although the underlying pathophysiology of reduced BMD in GSD Ia remains unsolved, metabolic control should be optimized to correct as much as possible metabolic and endocrine abnormalities that may influence both bone matrix formation and bone mineral accretion.

Distribution of cytoskeletal proteins, integrins, leukocyte adhesion molecules and extracellular matrix proteins in plastic-embedded human and rat kidneys.

OBJECTIVE: To study the distribution of cytoskeletal proteins (actin, alpha-actinin, vinculin, beta-tubulin, keratin, vimentin, desmin), adhesion molecules for cell-matrix interations (very later antigens [VLA1-61, beta1, beta2 [CD18], vitronectin receptor [alphavbeta3], CD 11b), leukocyte adhesion molecules (ICAM-1) and extracellular matrix proteins (collagen IV, fibronectin, laminin, vitronectin) in human and rat kidneys by using a superior processing and immunohistochemical staining technique. STUDY DESIGN: Human and rat kidneys were fixed in 2% paraformaldehyde, dehydrated in acetone and processed in a new, low-toxic glycol, methacrylate mixture, especially developed for immunohistochemistry. Both the glomeruli and the interstitial areas were carefully examined and scored semiquantitatively. RESULTS: Immunostained plastic sections showed excellent morphology combined with remarkably well preserved antigenicity. CONCLUSION: The above mentioned provides an excellent tool for the accurate localization of a wide variety of antigens at the light microscopic level.

Proteoglycan changes in the extracellular matrix of lung tissue from patients with pulmonary emphysema.

To characterize the changes in the extracellular matrix in smoking-related pulmonary emphysema, we undertook immunohistochemical studies in lung tissues from controls (n = 7), from patients with mild (n = 11) and severe (n = 8) emphysema, and from patients with lung fibrosis (n = 6). We studied collagens, laminin, fibronectin, proteoglycans (PGs), and beta1-integrins. The majority of the patients with severe emphysema showed diminished staining for the interstitial PGs, decorin and biglycan, in the peribronchiolar area, compared with patients in the control and fibrosis groups. Only a minority of patients with mild emphysema showed this diminished staining. In contrast, decorin and biglycan were well preserved in the perivascular area of all of the specimens from the emphysema group. Heparan sulfate PG staining was diminished in the respiratory airspace walls of patients with emphysema and fibrosis. Staining for Types I, III, and IV collagen, as well as for laminin, fibronectin, and the integrins, showed no differences between the four groups. The specific loss of interstitial PGs may be crucial for elastic recoil loss and subsequent bronchiolar obstruction, as seen in patients with smoking-related emphysema.

Differential effects of nitric oxide synthase inhibitors on endotoxin-induced liver damage in rats.

BACKGROUND & AIMS: During endotoxemia, expression of inducible nitric oxide synthase (iNOS) and nitric oxide production in the liver is increased. NO has been suggested to have a hepatoprotective function. The aim of this study was to investigate the distribution of iNOS and the effect of different NO synthase inhibitors on liver damage and hemodynamics during endotoxemia. METHODS: Rats were injected with lipopolysaccharide (LPS) and received the NOS-inhibitor S-methylisothiourea (SMT) or NG-nitro-L-arginine methyl ester (L-NAME). iNOS induction was assessed by Western blot, immunohistochemistry, and measurement of NO metabolites in plasma and bile. Liver damage was determined by aspartate aminotransferase and alanine aminotransferase and by histology. The effects of both inhibitors on systemic and portal pressure were measured in normal and LPS-treated rats. RESULTS: LPS treatment strongly induced iNOS in inflammatory cells, macrophages, bile duct epithelium, and hepatocytes, especially at the canalicular membrane. LPS-induced liver damage strongly increased after L-NAME. SMT caused a similar reduction of NO production without enhancing liver damage. In LPS-treated rats, SMT increased the systemic and portal pressure significantly more than L-NAME. CONCLUSIONS: During endotoxemia, administration of the NOS-inhibitor L-NAME aggravates liver damage. This liver damage does not seem to be caused by hemodynamic changes. In contrast, SMT caused significant hemodynamic changes but did not increase LPS-induced liver damage.

Characterization of a rat glomerular visceral epithelial cell line.

Cultures of glomerular epithelial cells (GEC) are currently used to identify important cellular and molecular mechanisms involved in the pathogenesis of renal diseases. However, there is still controversy in the literature as to the visceral or parietal origin of cultured GEC. Our aim was to firmly establish the nature of a GEC cell line. The reactivity of cultured GEC was investigated with a large panel of mono- and polyclonal antibodies by using immunofluorescent techniques and compared with literature data on the in vivo expression of these antigens on podocytes. In addition, the podocyte specific 5A (podocalyxin), 13A and 27A (9-O-acetylated GD3) antigen expression was investigated in immuno-overlay experiments with isolated gangliosides and in immunoprecipitations with metabolically labelled cells. In general, immunoreactivities between cultured GEC and literature data on GEC in vivo expressions were similar. Important podocyte epitopes in vivo were expressed by cultured GEC such as podocalyxin, gp330 and the 13A antigen. Cultured GEC however differed from their in vivo counterparts in their expression of keratin-18, their lack of expression of pp44 and no detectable immunohistological expression of the ganglioside 9-O-acetylated GD3. Interestingly, the podocyte-specific epitope 9-O-acetylated GD3 was detected by the 27A antibodies in immuno-overlays of isolated GEC gangliosides. Moreover, by using the 27A antibody, we were able to precipitate the podocyte-specific 103-kD protein from 35S-methionine metabolically labelled GEC. From our immunohistological data together with the detectability of the 27A antigen we conclude that the cell line we use very probably originates from glomerular visceral epithelial cells.

Biological alterations of rat podocytes cultured under basolateral hydrostatic pressure.

In vivo, glomerular visceral epithelial cells (GVEC), or podocytes, are morphologically highly differentiated cells which are in close contact with adjacent cells by complex interdigitating foot processes. In vitro, the dedifferentiated appearance of podocytes hampers investigations on podocyte structure and function. Cultured podocytes resemble simple epithelium in several ways with apical tight junctions and absence of foot processes. The morphological resemblances between GVEC early in embryonic development, in proteinuric diseases and in cultured cells are striking, but the mechanisms involved in these (de)differentiation processes are poorly understood. A common feature of GVEC in these various states of dedifferentiation is their altered exposure to or even total lack of hydrostatic pressure, suggesting that this may be one of the parameters involved in GVEC differentiation. In this study we investigated whether basolateral hydrostatic pressure could affect GVEC biology in vitro. We therefore exposed cultured GVEC grown on porous supports to basolateral hydrostatic pressure and investigated morphology with scanning and transmission electron microscopy, expression of specific podocyte markers and their biological responses to a model stimulus, the cytokine IFN-gamma. Morphologically, monolayers of pressurized GVEC contained large regions of whirl-like, raised cell formations. Individual cells in these formations had a rounded morphology and pore-like indentations between adjacent cells were observed. Cell-cell contacts were often found more basally and intercellular spaces were widened. Moreover, protein expression of pressurized monolayers was altered, as demonstrated by regions of cells with decreased keratin expression. Finally, upon exposure to the model stimulus IFN-gamma, the pressurized as compared to the control GVEC demonstrated a 3-fold increased expression of MHC class II and a strongly decreased sensitivity to the toxic effects of IFN-gamma. In conclusion, we found several indications that hydrostatic pressure can affect podocyte biology in vitro and similar mechanisms may account for podocyte biology in vivo. The strikingly altered morphology and biology of pressurized GVEC suggest that this culture system can be quite relevant for future studies with cultured GVEC.