Metabolic flux from the Krebs cycle to glutamate transmission tunes a neural brake on seizure onset

Kohlschutter-Tonz syndrome (KTS) manifests as neurological dysfunctions, including early-onset seizures. Mutations in the citrate transporter SLC13A5 are associated with KTS, yet their underlying mechanisms remain elusive. Here, we report that a Drosophila SLC13A5 homolog, I'm not dead yet (Indy), constitutes a neurometabolic pathway that suppresses seizure. Loss of Indy function in glutamatergic neurons caused "bang-induced" seizure-like behaviors. In fact, glutamate biosynthesis from the citric acid cycle was limiting in Indy mutants for seizure-suppressing glutamate transmission. Oral administration of the rate-limiting alpha-ketoglutarate in the metabolic pathway rescued low glutamate levels in Indy mutants and ameliorated their seizure-like behaviors. This metabolic control of the seizure susceptibility was mapped to a pair of glutamatergic neurons, reversible by optogenetic controls of their activity, and further relayed onto fan-shaped body neurons via the ionotropic glutamate receptors. Accordingly, our findings reveal a micro-circuit that links neural metabolism to seizure, providing important clues to KTS-associated neurodevelopmental deficits. Author summary Kohlschutter-Tonz syndrome (KTS) is a neurodevelopmental disorder linked to two distinct genomic loci encoding the citrate transporter SLC13A5 and synaptic protein ROGDI, respectively. An early-onset seizure is the most prominent neurological symptom in KTS patients, yet how these genes contribute to the control of seizure susceptibility remains poorly understood. Our study establishes behavioral models of seizure in Drosophila mutants of KTS-associated genes and demonstrates a genetic, metabolic, and neural pathway of seizure suppression. We discover that the metabolic flux of the Krebs cycle to glutamate biosynthesis plays a critical role in scaling seizure-relevant glutamate transmission. We further map this seizure-suppressing pathway to a surprisingly small number of glutamatergic neurons and their ionotropic glutamate transmission onto a key sleep-promoting locus in the adult fly brain. Given that the excitatory amino acid glutamate is considered a general seizure-promoting neurotransmitter, our findings illustrate how glutamatergic transmission can have opposing effects on seizure susceptibility in the context of a micro-neural circuit, possibly explaining drug-resistant epilepsy. This seizure-suppressing locus in the Drosophila brain is also implicated in metabolism, circadian rhythms, and sleep, revealing the conserved neural principles of their intimate interaction with epilepsy across species

Assessing Environmentally Sensitive Land to Desertification Using MEDALUS Method in Mongolia

Desertification is a global phenomenon caused by various processes, including climate change, vegetation processes, and human activities. The need to combat desertification is increasing in many countries. A reasonable assessment of the vulnerability or sensitivity of land cover to desertification at national scales is crucial to formulate appropriate strategies or policies for combating it. The main purpose of this work was to quantitatively assess the sensitivity of land cover to desertification in Mongolia using the MEDALUS approach. The MEDALUS method is a widely known technique for assessing desertification in the Mediterranean area. In this study, the method was adjusted to be applied to Mongolia, while the numerical methods of the MEDALUS remained the same. The modified MEDALUS method used nine factors from 2003 and 2008 to quantify the sensitivity of land to desertification. As a result, our study resulted in the calculation and spatial distribution of the Environmental Sensitive Area Index (ESAI), produced throughout Mongolia. In 2003, the middle region of the southern Mongolia had the highest sensitivity to desertification, while sensitivity in 2008 increased in the western area. Mongolia’s area with the highest ESAI range increased approximately five times, indicating rapid desertification occurring throughout Mongolia from 2003 to 2008

Characteristics of second primary breast cancer after ovarian cancer: a Korea central cancer registry retrospective study

BackgroundSecond primary cancer has become an important issue among cancer survivors. This study sought to determine the differences in clinicopathologic outcomes between second primary breast cancer (SPBC) after ovarian cancer and primary breast cancer (PBC) in the Republic of Korea.Methods and materialsWe searched the Korea Central Cancer Registry and identified 251,244 breast cancer cases that were diagnosed between 1999 and 2017. The incident rate and standardized incidence ratio (SIR) were calculated. Demographic and clinical characteristics and overall survival (OS) rates were estimated according to age, histological type, and cancer stage.ResultsAmong the 228,329 patients included, 228,148 were patients with PBC, and 181 patients had SPBC diagnosed after ovarian cancer (OC). The mean ages at diagnosis were 56.09 ± 10.81 years for SPBC and 50.65 ± 11.40 years for PBC. Patients with SPBC were significantly less likely than patients with PBC to receive adjuvant radiotherapy (14.92% vs. 21.92%, p = 0.02) or adjuvant chemotherapy (44.75% vs. 55.69%, p < 0.01). Based on the age-standardized rate (ASR), the incidence of SPBC after OC was 293.58 per 100,000 ovarian cancer patients and the incidence of PBC was 39.13 per 100,000 women. The SIR for SPBC was 1.27 (1.09-1.46, 95% Confidence interval) in the patients overall. The 5-year OS rates were 72.88% and 89.37% for SPBC and PBC (p < 0.01). The OS rate in SPBC decreased significantly with advanced stage and older age.ConclusionThe incidence of breast cancer is about 1.27 times higher in ovarian cancer patients than in healthy people. The survival outcomes were worse for SPBC than for PBC and were related to older age and advanced stage. Active screening for breast cancer is necessary in ovarian cancer patients

Synthesis and Thermoelectric Characterization of Lead Telluride Hollow Nanofibers

Lead telluride (PbTe) nanofibers were fabricated by galvanic displacement of electrospun cobalt nanofibers where their composition and morphology were altered by adjusting the electrolyte composition and diameter of sacrificial cobalt nanofibers. By employing Co instead of Ni as the sacrificial material, residue-free PbTe nanofibers were synthesized. The Pb content of the PbTe nanofibers was slightly affected by the Pb2+ concentration in the electrolyte, while the average outer diameter increased with Pb2+ concentration. The surface morphology of PbTe nanofibers was strongly dependent on the diameter of sacrificial nanofibers where it altered from smooth to rough surface as the Pb2+ concentration increased. Some of thermoelectric properties [i.e., thermopower (S) and electrical conductivity(σ)] were systematically measured as a function of temperature. Energy barrier height (Eb) was found to be one of the key factors affecting the thermoelectric properties–that is, higher energy barrier heights increased the Seebeck coefficient, but lowered the electrical conductivity

Enhanced Ex Vivo Expansion of Human Adipose Tissue-Derived Mesenchymal Stromal Cells by Fibroblast Growth Factor-2 and Dexamethasone

In the present study, we investigated the ex vivo expansion of human adipose tissue-derived mesenchymal stromal cells (ATSCs) to identify factors that promoted efficient expansion while preserving stem cell potential. We examined several growth factors and steroids, and found that the combination of a low concentration of fibroblast growth factor-2 (FGF-2) (1 ng/mL) and dexamethasone (DEX) or betamethasone (BET) enhanced the proliferation of ATSCs by approximately 30-60% as compared to control. Enhanced proliferation under these conditions was confirmed using ATSCs isolated from three independent donors. ATSCs that were expanded in the presence of FGF-2 and DEX for 5 days were capable of differentiating into either osteoblastic or adipogenic cells, and the cells were positive for the mesenchymal stem cell markers such as CD29, CD44, CD90, CD105, and CD146, suggesting that the stem cell potential of the ATSCs was preserved. Analysis of signaling pathway revealed that tyrosine phosphorylation of Src kinase was dramatically increased in response to FGF-2 and DEX, suggesting the involvement of Src-dependent pathways in the stimulatory mechanism of proliferation of ATSCs by FGF-2 and DEX. Moreover, Src family kinase inhibitors (SU6656 and Src kinase inhibitor I) substantially reduced the FGF-2 and DEX-induced proliferation of ATSCs. SU6656 also inhibited the osteogenic and adipogenic differentiation of ATSCs. The results of the current study demonstrate that FGF-2 in combination with DEX stimulates the proliferation and osteoblastic and adipogenic differentiation of ATSCs through a Src-dependent mechanism, and that FGF-2 and DEX promote the efficient ex vivo expansion of ATSCs.This work was supported by a grant from the Ministry of Health and Welfare [0405-BO01-0204-0006] and by a Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MOST); Grant Numbers: M10646020001-06N4602-00110 and No. R01-2006-000-10756-0).1

Anti-Biofouling Features of Eco-Friendly Oleamide-PDMS Copolymers

The biofouling of marine organisms on a surface induces serious economic damage. One of the conventional anti-biofouling strategies is the use of toxic chemicals. In this study, a new eco-friendly oleamide-PDMS copolymer (OPC) is proposed for sustainable anti-biofouling and effective drag reduction. The anti-biofouling characteristics of the OPC are investigated using algal spores and mussels. The proposed OPC is found to inhibit the adhesion of algal spores and mussels. The slippery features of the fabricated OPC surfaces are examined by direct measurement of pressure drops in channel flows. The proposed OPC surface would be utilized in various industrial applications including marine vehicles and biomedical devices. © Copyright © 2020 American Chemical Society.1