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Pendred Syndrome
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
There is tangible evidence that mutations in the FOXI1 gene on chromosome 5q35.1 encoding forkhead box protein I1 and the KCNJ10 gene on chromosome 1q23.2 encoding the ATP-sensitive inward rectifier potassium channel 10 may be implicated in about 2% of non-classic Pendred syndrome (also known as nonsyndromic enlarged vestibular aqueduct [NSEVA]), but not classic Pendred syndrome. Further, biallelic KCNJ10 pathogenic variants are involved in SeSAME syndrome (seizures, sensorineural deafness, ataxia, mental retardation, and electrolyte imbalance) and EAST syndrome (epilepsy, ataxia, sensorineural deafness, and tubulopathy) [17,18].
Maturation, Barrier Function, Aging, and Breakdown of the Blood–Brain Barrier
Published in Shamim I. Ahmad, Aging: Exploring a Complex Phenomenon, 2017
Elizabeth de Lange, Ágnes Bajza, Péter Imre, Attila Csorba, László Dénes, Franciska Erdő
Astroglial perivascular connectivity occurs and develops during postnatal BBB maturation (days 2–20). The absence of astroglial connexins (Cx30 and Cx43) weakens the BBB, which opens upon increased hydrostatic vascular pressure and shear stress, demonstrating that astroglial connexins are necessary to maintain BBB integrity (Ezan et al. 2012, Elahy et al. 2015). Perivascular astrocyte end feet have intramembranous particles as water channel AQP4 and the adenosine triphosphate (ATP)-sensitive inward rectifier potassium channel Kir4 (Kostic et al. 2013). The astrocyte lineages influence the BBB phenotype of the cerebral endothelium. Astrocyte precursors release soluble factors (IL-6, glial cell-derived neurotrophic factor [GDNF], FGF-2) that determine the fate of cerebral vascular ECs and define an elevated expression of transporters and increased TJ formation (Obermeier et al. 2013, Elahy et al. 2015). Astrocytes also produce the cholesterol and phospholipid transporter molecule apolipoprotein E (APOE), which mediates regulatory processes related to brain homeostasis (Gee and Keller 2005).
Tongmai Yangxin pill alleviates myocardial no-reflow by activating GPER to regulate HIF-1α signaling and downstream potassium channels
Published in Pharmaceutical Biology, 2023
Ting Chen, Yulong Zhang, Manyun Chen, Pu Yang, Yi Wang, Wei Zhang, Weihua Huang, Wei Zhang
The microvascular ring of the left anterior descending branch was suspended between two parallel steel hooks in an organ bath. To keep the blood vessels alive, the organ bath was maintained at 37.0 °C and bubbled with 95% O2 and 5% CO2. After vascular balance, 5 mL of the KPSS solution (composition and batch numbers listed in Table 1) was used to stimulate the blood vessels to reach the vascular ring leveling stage, and the PSS buffer (composition and batch numbers listed in Table 2) was used to wash the blood vessels 2 times/10 min. KPSS stimulation of the blood vessels was repeated twice, and if the contractile tension was >2 mN, the vascular ring was considered to exhibit good activity. Vascular tension was recorded using a microvascular tension sensor (Danish Myo Technology A/S). In order to observe whether TMYX can alleviate NR by activating GPER to regulate the HIF-1α pathway and downstream potassium channel, a GPER blocker (G-15, Batch No. 1161002-05-6, MCE, China), PKA blocker (H-89, Batch No. B 1427, Sigma, USA), eNOS blocker (L-NAME, Batch No. N 5751, Sigma, USA), sGC inhibitor (ODQ, Batch No. O 3636, Sigma, USA), and four K+ channel (calcium-activated potassium channel, ATP-sensitive potassium channel, inward rectifier potassium channel, and voltage-dependent potassium channel) inhibitors (TEA: Batch No. T2265-25G, Gli: Batch No. G0639-5G-9, Bacl2: Batch No. 202738-5 G, 4-AP: Batch No. 275875-1 G, Sigma, USA) were administered to the isolated coronary microvasculature.
Precision medicine in cardiac electrophysiology: where we are and where we need to go
Published in Expert Review of Precision Medicine and Drug Development, 2020
Ashish Correa, Syed Waqas Haider, Wilbert S. Aronow
Short QT Syndrome (SQTS) is an extremely rare congenital arrhythmia syndrome characterized a very short QT interval (</=330 ms) in the context of a structurally normal heart and no electrolyte abnormalities [59]. The first presentation of these patients is often cardiac arrest. These patients also have a predisposition to develop AF. The diagnosis is made by an EKG finding of a QTc interval </=330 ms or </=360 ms and either a genetic mutation, a personal history of cardiac arrest or a family history of SCD or SQTS. Using candidate gene approaches, mutations in the KCNH2, gene that encodes the hERG potassium channel that in turn regulates the inward repolarizing IKr current, were identified as a cause autosomal dominant SQTS (called SQT1) [68,69]. Similarly, candidate gene approaches were used to identify mutations in KCNQ1 [70–72] (encoding the potassium channel that facilitates the IKs current) and in KCNJ2 [73] (encoding an inward-rectifier potassium channel); mutations at these loci cause SQT2 and SQT3, respectively. Unlike in LQTS where loss-of-function mutations in these genes prolong the QT interval, in SQTS gain-of-function mutations result in rapid repolarization, shortening of the QT interval and a predisposition to develop polymorphic VTs (Figure 4).
A Newborn with Congenital Hyperinsulinism
Published in Fetal and Pediatric Pathology, 2019
Yiting Du, Rong Ju, Yufeng Xi, Peng Gou
ABCC8 was the first gene found to be involved in the pathogenesis of CHI, and more than 150 mutations have been discovered to date. This gene is located on chromosome 11pl5.1 and encodes sulfonylurea receptor 1 (sUR1). sUR1 and inward rectifier potassium channel protein (Kir6), which is encoded by the KCNJll gene, form a KATP channel that is involved in regulating insulin secretion. A large number of studies have shown that loss-of-function mutations in ABCC8 and KCNJll can cause excessive insulin secretion, leading to the occurrence of KATP-CHI [8]. ABCC8 gene mutations can be divided into the following two types according to their impact: type I mutations mainly affect expression of KATP channel proteins on the surface of islet B cell membranes, reducing the number of KATP channels; type II mutations involve impaired KATP channel function, resulting in closed channels.