Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy.

Gain-of-function (GOF) variants in K+ channels cause severe childhood epilepsies, but there are no mechanisms to explain how increased K+ currents lead to network hyperexcitability. Here, we introduce a human Na+-activated K+ (KNa) channel variant (KCNT1-Y796H) into mice and, using a multiplatform approach, find motor cortex hyperexcitability and early-onset seizures, phenotypes strikingly similar to those of human patients. Although the variant increases KNa currents in cortical excitatory and inhibitory neurons, there is an increase in the KNa current across subthreshold voltages only in inhibitory neurons, particularly in those with non-fast-spiking properties, resulting in inhibitory-neuron-specific impairments in excitability and action potential (AP) generation. We further observe evidence of synaptic rewiring, including increases in homotypic synaptic connectivity, accompanied by network hyperexcitability and hypersynchronicity. These findings support inhibitory-neuron-specific mechanisms in mediating the epileptogenic effects of KCNT1 channel GOF, offering cell-type-specific currents and effects as promising targets for therapeutic intervention

Binary orbits as the driver of γ-ray emission and mass ejection in classical novae

Classical novae are the most common astrophysical thermonuclear explosions, occurring on the surfaces of white dwarf stars accreting gas from companions in binary star systems. Novae typically expel �10,000 solar masses of material at velocities exceeding 1,000 km/s. However, the mechanism of mass ejection in novae is poorly understood, and could be dominated by the impulsive flash of the thermonuclear runaway, prolonged optically thick winds, or binary interaction with the nova envelope. Classical novae are now routinely detected in GeV gamma-rays, suggesting that relativistic particles are accelerated by strong shocks in nova ejecta. Here we present high-resolution imaging of the gamma-ray-emitting nova V959 Mon at radio wavelengths, showing that its ejecta were shaped by binary motion: some gas was expelled rapidly along the poles as a wind from the white dwarf, while denser material drifted out along the equatorial plane, propelled by orbital motion. At the interface between the equatorial and polar regions, we observe synchrotron emission indicative of shocks and relativistic particle acceleration, thereby pinpointing the location of gamma-ray production. Binary shaping of the nova ejecta and associated internal shocks are expected to be widespread among novae, explaining why many novae are gamma-ray emitters

Developing Telemental Health Partnerships Between State Medical Schools and Federally Qualified Health Centers: Navigating the Regulatory Landscape and Policy Recommendations

BackgroundFederally Qualified Health Centers (FQHCs) deliver care to 26 million Americans living in underserved areas, but few offer telemental health (TMH) services. The social missions of FQHCs and publicly funded state medical schools create a compelling argument for the development of TMH partnerships. In this paper, we share our experience and recommendations from launching TMH partnerships between 12 rural FQHCs and 3 state medical schools.ExperienceThere was consensus that medical school TMH providers should practice as part of the FQHC team to promote integration, enhance quality and safety, and ensure financial sustainability. For TMH providers to practice and bill as FQHC providers, the following issues must be addressed: (1) credentialing and privileging the TMH providers at the FQHC, (2) expanding FQHC Scope of Project to include telepsychiatry, (3) remote access to medical records, (4) insurance credentialing/paneling, billing, and supplemental payments, (5) contracting with the medical school, and (6) indemnity coverage for TMH.RecommendationsWe make recommendations to both state medical schools and FQHCs about how to overcome existing barriers to TMH partnerships. We also make recommendations about changes to policy that would mitigate the impact of these barriers. Specifically, we make recommendations to the Centers for Medicare and Medicaid about insurance credentialing, facility fees, eligibility of TMH encounters for supplemental payments, and Medicare eligibility rules for TMH billing by FQHCs. We also make recommendations to the Health Resources and Services Administration about restrictions on adding telepsychiatry to the FQHCsâ Scope of Project and the eligibility of TMH providers for indemnity coverage under the Federal Tort Claims Act.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149739/1/jrh12323_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149739/2/jrh12323.pd

A tetraoxane-based antimalarial drug candidate that overcomes PfK13-C580Y dependent artemisinin resistance.

K13 gene mutations are a primary marker of artemisinin resistance in Plasmodium falciparum malaria that threatens the long-term clinical utility of artemisinin-based combination therapies, the cornerstone of modern day malaria treatment. Here we describe a multinational drug discovery programme that has delivered a synthetic tetraoxane-based molecule, E209, which meets key requirements of the Medicines for Malaria Venture drug candidate profiles. E209 has potent nanomolar inhibitory activity against multiple strains of P. falciparum and P. vivax in vitro, is efficacious against P. falciparum in in vivo rodent models, produces parasite reduction ratios equivalent to dihydroartemisinin and has pharmacokinetic and pharmacodynamic characteristics compatible with a single-dose cure. In vitro studies with transgenic parasites expressing variant forms of K13 show no cross-resistance with the C580Y mutation, the primary variant observed in Southeast Asia. E209 is a superior next generation endoperoxide with combined pharmacokinetic and pharmacodynamic features that overcome the liabilities of artemisinin derivatives

A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe

PTEN is required to maintain luminal epithelial homeostasis and integrity in the adult mammary gland

AbstractIn the mammary gland, PTEN loss in luminal and basal epithelial cells results in differentiation defects and enhanced proliferation, leading to the formation of tumors with basal epithelial characteristics. In breast cancer, PTEN loss is associated with a hormone receptor-negative, basal-like subtype that is thought to originate in a luminal epithelial cell. Here, we show that luminal-specific PTEN loss results in distinct effects on epithelial homeostasis and mammary tumor formation. Luminal PTEN loss increased proliferation of hormone receptor-negative cells, thereby decreasing the percentage of hormone receptor-positive cells. Moreover, luminal PTEN loss led to misoriented cell divisions and mislocalization of cells to the intraluminal space of mammary ducts. Despite their elevated levels of activated AKT, Pten-null intraluminal cells showed increased levels of apoptosis. One year after Pten deletion, the ducts had cleared and no palpable mammary tumors were detected. These data establish PTEN as a critical regulator of luminal epithelial homeostasis and integrity in the adult mammary gland, and further show that luminal PTEN loss alone is not sufficient to promote the progression of mammary tumorigenesis

<i>mPINC</i> associates with PRC2 in the 16-day pregnant mammary gland.

<p>(A–D) RIP assays were performed with MECs purified from mammary glands at day 16 of pregnancy using antibodies to PRC2 members and its associated histone modification, H3meK27. Antibodies to MLL1 and its associated histone modification, H3meK4, were also used as negative controls. (A) RT-PCR shows <i>mPINC</i> is associated with PRC2 members and H3meK27. <i>mPINC</i> does not associate with MLL1 or H3meK4. (B–D) qPCR shows fold enrichment of <i>mPINC</i> transcript levels associated with EZH2 (B), SUZ12 (C) RpAp46 (D) and MLL1 (E) relative to <i>Gapdh</i> levels. Data represent mean ± SD (n = 3).</p

Knockdown of <i>mPINC</i> enhances differentiation of HC11 cells.

<p>(A, B) To target <i>mPINC1.0</i> and <i>mPINC1.6</i> (siPINC1.0/1.6), but not <i>DCR2</i>, siRNAs #1 and #2 were used in combination. To target all splice variants (siPINC), siRNAs #1 and #3 were used in combination. (A) Schematic showing siRNA targets of <i>mPINC</i> splice forms. (B) qPCR shows knockdown of <i>mPINC</i> 5 days post-transfection of siRNAs. Target genes were normalized to <i>Gapdh</i> and set relative to levels in the siNEG control transfected HC11 cells. (C, D) Knockdown of <i>mPNC</i> (siPINC1.0/1.6 and siPINC) splice forms increases <i>Wap</i> and <i>Ltf</i>, but not <i>Csn2</i>, expression at 24 (C) and 72 (D) hrs post-hormone induction. Target genes were normalized to <i>Gapdh</i> and set relative to levels in siNEG treated control cells. Data are presented as mean ± SEM (n = 3). (E, F) Knockdown of <i>mPINC</i> also increases dome formation compared to a control. (E) Representative brightfield images show domes following 48 hrs of hormone treatment. Scale bars represent 50 µm. (F) Domes were counted at 48 hours post-hormone treatment from nine 20× fields/experiment and data represent mean ± SEM set relative to the dome number in the siNEG treated control group (n = 6).</p

Structural analysis of the <i>PINC</i> locus.

<p>(A) Genomic representation of the <i>PINC</i> locus showing alternate isoforms <i>mPINC1.0</i>, <i>mPINC1.6</i> and <i>DCR2</i>. Regions of evolutionarily conserved RNA structures were predicted by SISSIz (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002840#s4" target="_blank">Methods</a>). (B–D) Circle plot secondary structure representations of interacting nucleotides in <i>mPINC1.0</i> (B), <i>mPINC1.6</i> (C) and <i>DCR2</i> (D). The probability of the interactions is color-coded according to the legend (right). Secondary structures were computed using the RNAstructure software (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002840#s4" target="_blank">Methods</a>). (E–F) High-confidence localized hairpin structures that represent possible protein-interaction sites and their most stable 3D representations, as modelled by MC-FOLD/MC-SYM. The corresponding regions in B–D are indicated by S1, for structure 1 (E) and by S2, for structure 2 (F) grey arcs.</p