Studies assessing mechanisms of proximal tubular cell (PTC) physiology and pathophysiology increasingly utilize cell culture systems to avoid the complexity of whole organ/whole animal experiments. However, no well-differentiated PTC line derived from adult human kidney currently exists. Therefore, the goal of this research was to establish such a line by transduction with human papilloma virus (HPV 16) E6/E7 genes. A primary PTC culture from normal adult human renal cortex was exposed to a recombinant retrovirus containing the HPV 16 E6/E7 genes, resulting in a cell line designated HK-2 (human kidney-2) which has grown continuously in serum free media for more than one year. HK-2 cell growth is epidermal growth factor dependent and the cells retain a phenotype indicative of well-differentiated PTCs (positive for alkaline phosphatase, gamma glutamyltranspeptidase, leucine aminopeptidase, acid phosphatase, cytokeratin, alpha 3 beta 1 integrin, fibronectin; negative for factor VIII-related antigen, 6.19 antigen and CALLA endopeptidase). Furthermore, HK-2 cells retain functional characteristics of proximal tubular epithelium (Na+ dependent/phlorizin sensitive sugar transport; adenylate cyclase responsiveness to parathyroid, but not to antidiuretic, hormone). The E6/E7 genes are present in the HK-2 genome, as determined by PCR. To assess its potential usefulness as a tool for studying injury and repair, HK-2 cells were exposed to a toxic concentration of H2O2 +/- iron chelation (deferoxamine) or hydroxyl radical scavenger (Na benzoate) therapy. Only the former blocked H2O2 cytotoxicity, reproducing results previously obtained with freshly isolated rat proximal tubular segments. In conclusion, an immortalized adult human PTC line has been established by transduction with HPV 16 E6/E7 genes. It appears to be well-differentiated on the basis of its histochemical, immune cytochemical, and functional characteristics, and it can reproduce experimental results obtained with freshly isolated PTCs. Thus, this new PTC line could have substantial research application.

Studies over the last decade have provided exciting new insights into potential mechanisms underlying the pathogenesis of preeclampsia. The initiating event in preeclampsia is generally regarded to be placental ischemia/hypoxia, which in turn results in the elaboration of a variety of factors from the placenta that generates profound effects on the cardiovascular system. This host of molecules includes factors such as soluble fms-like tyrosine kinase-1, the angiotensin II type 1 receptor autoantibody, and cytokines such as tumor necrosis factor-alpha, which generate widespread dysfunction of the maternal vascular endothelium. This dysfunction manifests as enhanced formation of factors such as endothelin, reactive oxygen species, and augmented vascular sensitivity to angiotensin II. Alternatively, the preeclampsia syndrome may also be evidenced as decreased formation of vasodilators such as nitric oxide and prostacyclin. Taken together, these alterations cause hypertension by impairing renal pressure natriuresis and increasing total peripheral resistance. Moreover, the quantitative importance of the various endothelial and humoral factors that mediate vasoconstriction and elevation of arterial pressure during preeclampsia remains to be elucidated. Thus identifying the connection between placental ischemia/hypoxia and maternal cardiovascular abnormalities in hopes of revealing potential therapeutic regimens remains an important area of investigation and will be the focus of this review.

No abstract

No abstract

No abstract

Chronic and acute renal diseases, irrespective of the initiating cause, have inflammation and immune system activation as a common underlying mechanism. The purpose of this review is to provide a broad overview of immune cells and inflammatory proteins that contribute to the pathogenesis of renal disease, and to discuss some of the physiological changes that occur in the kidney as a result of immune system activation. An overview of common forms of acute and chronic renal disease is provided, followed by a discussion of common therapies that have antiinflammatory or immunosuppressive effects in the treatment of renal disease.

Abstract-Increased superoxide is thought to play a major role in vascular dysfunction in a variety of disease states.Superoxide dismutase (SOD) limits increases in superoxide; however, the functional significance of selected isoforms of SOD within the vessel wall are unknown. We tested the hypothesis that selective loss of CuZnSOD results in increased superoxide and altered vascular responsiveness in CuZnSOD-deficient (CuZnSOD Ϫ/Ϫ ) mice compared with wild-type (CuZnSOD ϩ/ϩ ) littermates. Total SOD activity was reduced (PϽ0.05) by approximately 60% and CuZnSOD protein was absent in aorta from CuZnSOD Ϫ/Ϫ as compared with wild-type mice. Vascular superoxide levels, measured using lucigenin (5 mol/L)-enhanced chemiluminescence and hydroethidine (2 mol/L)-based confocal microscopy, were increased (approximately 2-fold; PϽ0.05) in CuZnSOD Ϫ/Ϫ mice as compared with wild-type mice. Relaxation of the carotid artery in response to acetylcholine and authentic nitric oxide was impaired (PϽ0.05) in CuZnSOD Ϫ/Ϫ mice. For example, maximal relaxation to acetylcholine (100 mol/L) was 50Ϯ6% and 69Ϯ5% in CuZnSOD Ϫ/Ϫ and wild-type mice, respectively. Contractile responses of the carotid artery were enhanced (PϽ0.05) in CuZnSOD Ϫ/Ϫ mice in response to phenylephrine and serotonin, but not to potassium chloride or U46619. In vivo, dilatation of cerebral arterioles (baseline diameterϭ31Ϯ1 m) to acetylcholine was reduced by approximately 50% in CuZnSOD Ϫ/Ϫ mice as compared with wild-type mice (PϽ0.05). These findings provide the first direct insight into the functional importance of CuZnSOD in blood vessels and indicate that this specific isoform of SOD limits increases in superoxide under basal conditions. CuZnSOD-deficiency results in altered responsiveness in both large arteries and microvessels.

Abstract-Agonistic autoantibodies to the angiotensin II type I receptor (AT1-AA) and endothelin -1 (ET-1) are suggested to be important links between placental ischemia and hypertension during preeclampsia. Activation of the angiotensin II type 1 receptor (AT1R) increases endothelial cell production of ET-1; however, the importance of ET-1 in response to AT1-AA-mediated AT1 R activation during preeclampsia is unknown. Furthermore, the role of AT1-AA-mediated increases in blood pressure during pregnancy remains unclear. The objective of this study was to test the hypothesis that AT1-AA, increased to levels observed in preeclamptic women and placental ischemic rats, increases mean arterial pressure (MAP) by activation of the ET-1 system. Chronic infusion of purified rat AT1-AA into normal pregnant (NP) rats for 7 days increased AT1-AA from 0.68Ϯ0.5 to 10.88Ϯ1.1 chronotropic units (PϽ0.001). The increased AT1-AA increased MAP from 99Ϯ1 to 119Ϯ2 mm Hg (PϽ0.001). The hypertension was associated with significant increases in renal cortices (11-fold) and placental (4-fold) ET-1. To determine whether ET-1 mediates AT1-AA-induced hypertension, pregnant rats infused with AT1-AA and NP rats were treated with an ET A receptor antagonist. MAP was 100Ϯ1 mm Hg in AT1-AAϩET A antagonist-treated rats versus 98Ϯ2 mm Hg in ET A antagonist-treated rats. Collectively, these data support the hypothesis that one potential pathway whereby AT1-AAs increase blood pressure during pregnancy is by an ET-1-dependent mechanism. Key Words: preeclampsia Ⅲ hypertension Ⅲ kidney Ⅲ placenta Ⅲ inflammation T he initiating event in early onset preeclampsia is postulated to involve inadequate vascularization of the subplacental decidua with reduced placental perfusion that leads to hypertension during pregnancy by mechanisms not yet elucidated. 1,2 Recent studies have suggested that the production of agonistic autoantibodies to the angiotensin II (Ang II) type I receptor (AT1-AA) may be an important link between placental ischemia and hypertension in preeclamptic women. 3-8 The AT1-AA induces signaling in vascular cells that are blocked by an AT1 receptor antagonist including activating protein-1, calcineurin, and nuclear factor kappa B activation. 3,4,7 Recent studies by Zhou et al demonstrate that immunoglobulin isolated from preeclamptic women increases systolic blood pressure 4 days after retro-orbital injection into pregnant mice. 7,8 This hypertensive response was attenuated by administration of an AT1 receptor antagonist. Although these findings suggest that AT1-AAs from preeclamptic women increases blood pressure in pregnant mice, possibly by activation of the AT1 receptor, it remains unclear by what mechanism purified AT1-AA mediates hypertension during pregnancy.We recently reported that hypertension in response to reductions in uterine perfusion pressure in pregnant rats (RUPP) is associated with increased circulating levels of the AT1-AA. 9,10 Moreover, we found that the increased blood pressure response in RUPP pregnant rats decreased ma...