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Background Primary vesicoureteral reflux (PVUR) is the most common malformation of the kidney and urinary tract, and reflux nephropathy is a major cause of chronic kidney disease in children. Recently, we reported mutations in the tenascin XB gene (TNXB) as a cause of PVUR with joint hypermobility. Methods To define the role of rare variants in tenascin genes in the etiology of PVUR, we screened a cohort of patients with familial PVUR (FPVUR) and non-familial PVUR (NFPVUR) for rare missense variants inTNXB and the tenascin C gene (TNC) after excluding mutations in ROBO2 and SOX17. Results The screening procedure identified 134 individuals from 112 families with PVUR; two families with mutations in ROBO2 were excluded from further analysis. Rare missense variants in TNXB were found in the remaining 110 families, of which 5/55 (9 %) families had FPVUR and 2/55 (4 %) had NFPVUR. There were no differences in high-grade reflux or renal parenchymal scarring between patients with and without TNXB variants. All patients with TNXB rare variants who were tested exhibited joint hypermobility. Overall we were able to identify causes of FPVUR in 7/57 (12 %) families (9 % in TNXB and 3 % in ROBO2). Conclusions In conclusion, the identification of a rare missense variant in TNXB in combination with a positive family history of VUR and joint hypermobility may represent a non-invasive method to diagnose PVUR and warrants further evaluation in other cohorts., Author(s): Shan Elahi[sup.1] , Alison Homstad[sup.1] [sup.2] , Himani Vaidya[sup.1] [sup.2] , Jennifer Stout[sup.1] , Gentzon Hall[sup.2] [sup.3] , Guanghong Wu[sup.2] [sup.3] , Peter Conlon[sup.1] , Jonathan C. Routh[sup.1] [sup.4] [...]

TNF-[alpha] is recognized as a significant contributor to myocardial dysfunction. Although several studies suggest that members of the NF-[kappa]B family of transcription factors are essential regulators of myocardial TNF-[alpha] gene expression, recent developments in our understanding of the modulation of NF-[kappa]B activity through posttranslational modification of NF-[kappa]B subunits suggest that the present view of NF-[kappa]B-dependent cytokine expression in heart is incomplete. Therefore, the goal of the present study was to examine the role of p65 subunit phosphorylation in the regulation of TNF-[alpha], production in cultured neonatal ventricular myocytes. Bacterial LPS-induced TNF-[alpha] production is accompanied by a 12-fold increase in phosphorylation of p65 at [Ser.sup.536], a modification associated with enhancement of p65 trans-activation potential. Pharmacological inhibition of IKK-[beta] reduced LPS-induced TNF-[alpha] production 38-fold, TNF-[alpha] mRNA levels 6-fold, and I[kappa]B-[alpha] phosphorylation 5-fold and degraded [kappa]B-[alpha] 2-fold and p65 phosphorylation 6-fold. Overexpression of dominant-negative p65 reduced TNF-[alpha] production 3.5-fold, whereas overexpression of dominant-negative IKK-[beta] reduced LPS-induced TNF-[alpha] production 2-fold and p65 phosphorylation 2-fold. Overexpression of dominant-negative IKK-[alpha] had no effect on p65 phosphorylation or TNF-[alpha] production, revealing that IKK-[alpha], not IKK-[beta], plays a central role in regulation of p65 phosphorylation at [Ser.sup.536] and TNF-[alpha] production in heart. Finally, we demonstrated, using a chromatin immunoprecipitation assay, that LPS stimulates recruitment of [Ser.sup.536]-phosphorylated p65 to the TNF-[alpha] gene promoter in cardiac myocytes. Taken together, these data provide compelling evidence for the role of NF-[kappa]B signaling in TNF-[alpha] gene expression in heart and highlight the importance of this proinflammatory gene-regulatory pathway as a potential therapeutic target in the management of cytokine-induced myocardial dysfunction. signal transuction; gene expression; heart; cytokines

Although tumor necrosis factor (TNF)-[alpha] is implicated in numerous cardiac pathologies, the intracellular events leading to its production by heart cells are largely unknown. The goal of the present study was to identify the role of the transcription factor nuclear factor (NF)-[kappa]B in this process. Among the many inducers of TNF-[alpha] expression in myeloid cells, only lipopolysaccharide (LPS) led to its induction in cultured neonatal myocytes. LPS also activated the NF-[kappa]B pathway, as evidenced by the degradation of the inhibitory protein I[kappa]B and the appearance of NF-[kappa]B-binding complexes in nuclear extracts. Furthermore, inhibitors of NF-[kappa]B activation, such as lactacystin, MG132, and pyrrolidine dithiocarbamate, were found to completely block the production of TNF-[alpha] in response to LPS stimulation, indicating a requirement of NF-[kappa]B for TNF-[alpha] expression. However, interleukin-1[beta] and phorbol 12-myristate 13-acetate also activated NF-[kappa]B but did not evoke TNF-[alpha] expression, revealing that this factor is not sufficient for cytokine production. Detailed examination of the NF-[kappa]B cascade revealed that cardiac cells displayed a unique pattern of I[kappa]B degradation in response to LPS, with I[kappa]B[beta] but not I[kappa]B[alpha] being degraded upon stimulation. Additional]y, two specific p65-containing DNA-binding complexes were observed in the nuclear extracts of neonatal cardiomyocytes: an inducible complex that is necessary for TNF-[alpha] expression and a constitutive species. Taken together, these results reveal that NF-[kappa]B is not only involved in cytokine production but also may be linked to other pathways that subserve a constitutive, protective mechanism for the heart cell. lipopolysaccharide; nuclear factor-[kappa]b; interleukin-1[beta]; cytokine production

Pregnancy and estradiol decrease GTPase activity in the guinea pig uterine artery. Am J Physiol Heart Circ Physiol 281: H2168-H2175, 2001.--The mechanisms by which pregnancy redistributes cardiac output in an organ-specific manner are poorly understood. We propose that it is consequential to estrogen-mediated alterations in G protein-mediated signal transduction. Aortas and uterine (UAs) and mesenteric arteries (MAs) were obtained from late-pregnant, nonpregnant, or ovariectomized guinea pigs chronically treated with 17[beta]-estradiol. High-affinity GTPase activity was assayed enzymatically. The cGMP generated in response to the endothelium-dependent agonist ACh was measured in UAs incubated with or without cholera toxin (CTX, which inhibits [G.sub.s][alpha]). Pregnancy significantly decreased UA but not aorta or MA GTPase activity. 17[beta]-Estradiol decreased UA GTPase activity compared with untreated ovariectomized animals. ACh increased cGMP in pregnant but not nonpregnant UAs. Pretreatment of nonpregnant UAs with CTX increased ACh-induced cGMP levels similar to pregnancy. Thus pregnancy and estradiol decrease the GTPase activity of a CTX-sensitive G protein in UAs, increasing receptor-dependent cGMP release. This alteration in receptor-mediated G protein coupling in UAs may contribute to the characteristic cardiovascular adaptation to pregnancy. G proteins; nitric oxide; acetylcholine; estrogen