Publications by authors named "Pitt G"

Developmental and epileptic encephalopathies (DEEs), a class of devastating neurological disorders characterized by recurrent seizures and exacerbated by disruptions to excitatory/inhibitory balance in the brain, are commonly caused by mutations in ion channels. Disruption of, or variants in, were implicated as causal for a set of DEEs, but the underlying mechanisms were clouded because is expressed in both excitatory and inhibitory neurons, undergoes extensive alternative splicing producing multiple isoforms with distinct functions, and the overall roles of FGF13 in neurons are incompletely cataloged. To overcome these challenges, we generated a set of novel cell-type-specific conditional knockout mice.

View Article and Find Full Text PDF
Article Synopsis
  • - Timothy syndrome, caused by variants in the CACNA1C gene, was originally recognized for its cardiac symptoms (long QT syndrome) and physical abnormalities (syndactyly), but more recent research has unveiled a wider range of symptoms associated with different CACNA1C variants.
  • - A survey was conducted with parents of Timothy syndrome patients to gather information on various symptoms, grouping participants by genetic type and initial diagnosis to compare their conditions.
  • - The study found that patients commonly show both cardiac and extra-cardiac symptoms, such as neurodevelopmental issues and respiratory problems, regardless of their classification, indicating that the current understanding of "non-syndromic" cases may not fully capture the complexity of the disease.
View Article and Find Full Text PDF
Article Synopsis
  • * Researchers created a G406R knockin mouse model that exhibits TS features, including hypoglycemia, but surprisingly does not show increased beta cell activity or hyperinsulinism.
  • * The study unveils alternative mechanisms for hypoglycemia, such as impaired hormone responses and disrupted hypothalamic regulation of glucose levels, enhancing our understanding of how mutant channels impact TS.
View Article and Find Full Text PDF
Article Synopsis
  • Sudden Unexpected Death in Epilepsy (SUDEP) is a major concern for people with epilepsy, primarily linked to recurrent convulsive seizures.
  • Current research suggests that respiratory dysfunction is a key factor leading to SUDEP, rather than heart rhythm problems.
  • Continued studies aim to uncover predictive markers for SUDEP and develop targeted treatments to improve the lives and longevity of individuals with epilepsy.
View Article and Find Full Text PDF

Healthcare associated infections (HCAI) represent a significant burden worldwide contributing to morbidity and mortality and result in substantial economic consequences equating to billions annually. Although the impacts of HCAI have been felt for many years, the coronavirus pandemic has had a profound effect, escalating rates of HCAI, even with extensive preventative measures such as vaccination, personal protective equipment, and deep cleaning regimes. Therefore, there is an urgent need for new solutions to mitigate this serious health emergency.

View Article and Find Full Text PDF

Timothy syndrome (OMIM #601005) is a rare disease caused by variants in the gene . Timothy syndrome patients were first identified as having a cardiac presentation of Long QT and syndactyly of the fingers and/or toes, and an identical variant in , Gly406Arg. However, since this original identification, more individuals harboring diverse variants in have been identified and have presented with various cardiac and extra-cardiac symptoms.

View Article and Find Full Text PDF

Developmental and Epileptic Encephalopathies (DEEs), a class of devastating neurological disorders characterized by recurrent seizures and exacerbated by disruptions to excitatory/inhibitory balance in the brain, are commonly caused by mutations in ion channels. Disruption of, or variants in, were implicated as causal for a set of DEEs, but the underlying mechanisms were clouded because is expressed in both excitatory and inhibitory neurons, undergoes extensive alternative splicing producing multiple isoforms with distinct functions, and the overall roles of FGF13 in neurons are incompletely cataloged. To overcome these challenges, we generated a set of novel cell type-specific conditional knockout mice.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how the protein Rad influences heart function during stress by affecting calcium ion influx and contraction strength.
  • It focuses on specific phosphorylation sites on Rad (Ser272 and Ser300) that modulate its interaction with voltage-gated calcium channels, which are crucial for increasing cardiac output.
  • The findings suggest that Rad's ability to detach from the membrane is essential for enhancing calcium currents during sympathetic nervous system activation, especially when the heart is responding to threats.
View Article and Find Full Text PDF
Article Synopsis
  • Tendons transmit force from muscles to bones, which is crucial for movement and their development relies on mechanical loading and calcium (Ca) signaling.
  • The study focused on the Ca 1.2 voltage-gated Ca channel in tendon biology, revealing that it's highly expressed during tendon development but decreases in adults.
  • Results showed that enhancing Ca 1.2 activity leads to larger tendons with increased collagen production and specific growth factors, suggesting that Ca signaling plays a critical role in tendon formation and remodeling.
View Article and Find Full Text PDF

Cancer alters the function of multiple organs beyond those targeted by metastasis. Here we show that inflammation, fatty liver and dysregulated metabolism are hallmarks of systemically affected livers in mouse models and in patients with extrahepatic metastasis. We identified tumour-derived extracellular vesicles and particles (EVPs) as crucial mediators of cancer-induced hepatic reprogramming, which could be reversed by reducing tumour EVP secretion via depletion of Rab27a.

View Article and Find Full Text PDF

The pancreatic islets are composed of discrete hormone-producing cells that orchestrate systemic glucose homeostasis. Here we identify subsets of beta cells using a single-cell transcriptomic approach. One subset of beta cells marked by high CD63 expression is enriched for the expression of mitochondrial metabolism genes and exhibits higher mitochondrial respiration compared with CD63 beta cells.

View Article and Find Full Text PDF
Article Synopsis
  • Tendons are key structures that connect muscles to bones, and their development and healing rely on mechanical loading and calcium (Ca) signaling, though specifics about Ca signaling in tendon cells remain unclear.
  • In their study, researchers explored the role of the Ca 1.2 voltage-gated channel in tendon formation, finding it highly expressed during development but reduced in adults.
  • Mice engineered to express a gain-of-function Ca 1.2 channel showed larger tendons with increased fibroblast numbers, enhanced collagen formation, and significant changes in extracellular matrix proteins and growth factors related to tendon development.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the heart's contractile reserve and how it is affected by β-adrenergic signaling, which traditionally increases heart rate and contractility during stress.
  • Researchers find that specific sites on the protein Rad, when modified by a process called phosphorylation, are essential for controlling calcium flow into heart cells (cardiomyocytes), impacting heart performance.
  • Mutations in Rad lead to significant decreases in heart function under stress and regular conditions, but introducing modified calcium-channel proteins can restore heart function, indicating potential for new heart treatments.
View Article and Find Full Text PDF

Brain enriched voltage-gated sodium channel (VGSC) Na1.2 and Na1.6 are critical for electrical signaling in the CNS.

View Article and Find Full Text PDF

The sinoatrial node (SAN) is the primary pacemaker of the heart. The human SAN is poorly understood due to limited primary tissue access and limitations in robust derivation methods. We developed a dual knockin human embryonic stem cell (hESC) reporter line, which allows the identification and purification of SAN-like cells.

View Article and Find Full Text PDF

The publication of papers containing data obtained with suboptimal rigor in the experimental design and choice of key reagents, such as antibodies, can result in a lack of reproducibility and generate controversy that can both needlessly divert resources and, in some cases, damage public perception of the scientific enterprise. This exemplary paper by Buonarati (2018) shows how a previously published, potentially important paper on calcium channel regulation falls short of the necessary mark, and aims to resolve the resulting controversy.

View Article and Find Full Text PDF

Background: Increasing evidence suggests that cardiac arrhythmias are frequent clinical features of coronavirus disease 2019 (COVID-19). Sinus node damage may lead to bradycardia. However, it is challenging to explore human sinoatrial node (SAN) pathophysiology due to difficulty in isolating and culturing human SAN cells.

View Article and Find Full Text PDF

Calcific aortic valve disease (CAVD) is heritable, as revealed by recent GWAS. While polymorphisms linked to increased expression of CACNA1C - encoding the CaV1.2 L-type voltage-gated Ca2+ channel - and increased Ca2+ signaling are associated with CAVD, whether increased Ca2+ influx through the druggable CaV1.

View Article and Find Full Text PDF

Rapidly changing and transient protein-protein interactions regulate dynamic cellular processes in the cardiovascular system. Traditional methods, including affinity purification and mass spectrometry, have revealed many macromolecular complexes in cardiomyocytes and the vasculature. Yet these methods often fail to identify in vivo or transient protein-protein interactions.

View Article and Find Full Text PDF
Article Synopsis
  • CACNA1C is a gene that encodes a crucial part of a calcium channel found in the heart and brain, and variants in it have been linked to Timothy syndrome and long QT syndrome, but this study focuses on its neurological effects.
  • The study examined 25 individuals from 22 families with heterozygous variants in CACNA1C, showing a range of neurological issues like developmental delays, autism, hypotonia, ataxia, and epilepsy.
  • Results indicate that these variants can lead to different functional changes in the calcium channel, expanding the understanding of CACNA1C's role in neurodevelopmental disorders beyond previously known syndromes.
View Article and Find Full Text PDF

SCN2A, encoding the neuronal voltage-gated Na+ channel NaV1.2, is one of the most commonly affected loci linked to autism spectrum disorders (ASDs). Most ASD-associated mutations in SCN2A are loss-of-function mutations, but studies examining how such mutations affect neuronal function and whether Scn2a mutant mice display ASD endophenotypes have been inconsistent.

View Article and Find Full Text PDF