Human, Rat, Mouse, Porcine, Bovine, Canine, Rabbit, Monkey Endothelin-1 ELISA Kit

Aims Endothelin-1 (ET-1) is a potent vasoconstrictor peptide [inked to vascular diseases through a common intronic gene enhancer [(rs9349379-G allele), chromosome 6 (PHACTR1/EDN1)]. We performed a multimodality investigation into the role of ET-1 and this gene variant in the pathogenesis of coronary microvascular dysfunction (CMD) in patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (CAD). Methods and results Three hundred and ninety-one patients with angina were enrolled. Of these, 206 (53%) with obstructive CAD were excluded leaving 185 (47%) eligible. One hundred and nine (72%) of 151 subjects who underwent invasive testing had objective evidence of CMD (COVADIS criteria). rs9349379-G allele frequency was greater than in contemporary reference genome bank control subjects [allele frequency 46% (129/280 alleles) vs. 39% (5551/14380); P= 0.013]. The G allele was associated with higher plasma serum ET-1 [Least squares mean 1.59 pg/mL vs. 1.28 pg/mL; 95% confidence interval (CI) 0.10-0.53; P = 0.005]. Patients with rs9349379-G allele had over double the odds of CMD [odds ratio (OR) 2.33, 95% CI 1.10-4.96; P = 0.027]. Muttimodatity non-invasive testing confirmed the G allele was associated with linked impairments in myocardial perfusion on stress cardiac magnetic resonance imaging at 1.5T (N= 107; GG 56%, AG 43%, AA 31%, P= 0.042) and exercise testing (N= 87;-3.0 units in Duke Exercise Treadmill Score;-5.8 to-0.1; P= 0.045). Endothetin-1 related vascular mechanisms were assessed ex vivo using wire myography with endothelin A receptor (ETA) antagonists including zibotentan. Subjects with rs9349379-G allele had preserved peripheral small vessel reactivity to ET-1 with high affinity of ETA antagonists. Zibotentan reversed ET-1-induced vasoconstriction independently of G allele status. Conclusion We identify a novel genetic risk locus for CMD. These findings implicate ET-1 dysregulation and support the possibility of precision medicine using genetics to target oral ETA antagonist therapy in patients with microvascular angina.

Background The progression rate of CKD varies substantially among patients. The genetic and epigenetic contributions that modify how individual patients respond to kidney injury are largely unknown. Emerging evidence has suggested that histone H3 K79 methyltransferase Dot1l has an antifibrotic effect by repressing Edn1, which encodes endothelin 1 in the connecting tubule/collecting duct. Methods To determine if deletion of the Dot1l gene is a genetic and epigenetic risk factor through regulating Edn1, we studied four groups of mice: wild-type mice, connecting tubule/collecting duct- specific Dot1l conditional knockout mice (Dot1l(Ac)), Dot1l and Ednl double-knockout mice (DEAc), and Edn1 connecting tubule/collecting duct-specific conditional knockout mice (Edne(Ac)), under three experimental conditions (streptozotocin-induced diabetes, during normal aging, and after unilateral ureteral obstruction). We used several approaches (colocalization, glutathione S-transferase pulldown, coimmunoprecipitation, yeast two-hybrid, gel shift, and chromatin immunoprecipitation assays) to identify and confirm interaction of Dotla (the major Dot1l splicing variant in the mouse kidney) with histone deacetylase 2 (HDAC2), as well as the function of the Dotla-HDAC2 complex in regulating Ednl transcription. Results In each case, Dot1l(Ac) mice developed more pronounced kidney fibrosis and kidney malfunction compared with wild-type mice. These Dot1l(Ac) phenotypes were ameliorated in the double-knockout DE Ac mice. The interaction between Dot1a and HDAC2 prevents the Dot1a-HDAC2 complex from association with DNA, providing a counterbalancing mechanism governing Edn1 transcription by modulating H3 K79 dimethylation and H3 acetylation at the Edn1 promoter. Conclusions Our study confirms Dot1l to be a genetic and epigenetic modifier of kidney fibrosis, reveals a new mechanism regulating Ednl transcription by Dot1a and HDAC2, and reinforces endothelin 1 as a therapeutic target of kidney fibrosis.