Genotype–phenotype correlation of Charcot-Marie-Tooth type 1E patients with <Emphasis Type="Italic">PMP22</Emphasis> mutations

Charcot-Marie-Tooth disease type 1E (CMT1E) is a demyelinating motor and sensory neuropathy with peripheral myelin protein 22 (PMP22) point mutations. The objective of this study was to identify genetic causes and determine genotype–phenotype correlation in two Korean demyelinating CMT patients based on whole exome sequencing (WES), histological examination of distal sural nerve, and magnetic resonance imaging (MRI) of leg. WES revealed two de novo PMP22 mutations in the two demyelinating CMT patients, including one novel p.Leu82Pro (c.245T>A) mutation in one patient and one previously reported p.Ser72Leu (c.215C>T) mutation in the other patient. Both mutation sites were located in the well conserved second transmembrane domain. No control had the same mutations. The affected individual with the novel p.Leu82Pro mutation showed early onset, scoliosis, and sensory ataxia with ability to walk without assistance. Histopathological examination showed severe damage of myelin and axons. No compound muscle action potentials (CMAPs) were evoked in the upper or lower limb nerves. Leg MRIs revealed mild fatty infiltration of the bilateral peronei muscles consistent with clinical manifestations. The patient with the p.Ser72Leu mutation showed developmental delay in infancy. No CMAPs were elicited. However, she was also able to walk without assistance. In spite of markedly severe electrophysiological defects, leg MRIs showed almost normal findings except slight muscle atrophies of the lower legs. Both patients presented similar clinical features including no CMAPs in electrophysiological tests and mild fatty replacement in the lower leg MRI. Therefore, there was a good genotype–phenotype correlation in both cases.     

Serum 25-Hydroxyvitamin D Levels and Dry Eye Syndrome: Differential Effects of Vitamin D on Ocular Diseases

Purpose

To investigate associations between serum 25-hydroxyvitamin D levels and dry eye syndrome (DES), and to evaluate the differential effect of vitamin D on ocular diseases including age-related macular disease (AMD), diabetic retinopathy (DR), cataract, and DES.

Methods

A total of 16,396 participants aged >19 years were randomly selected from the Korean National Health and Nutrition Examination Survey. All participants participated in standardized interviews, blood 25-hydroxyvitamin D level evaluations, and comprehensive ophthalmic examinations. DES was defined by a history of clinical diagnosis of dry eyes by a physician. The association between vitamin D and DES was compared to the associations between vitamin D and AMD, DR, cataract, and DES from our previous studies.

Results

The odds of DES non-significantly decreased as the quintiles of serum 25-hydroxyvitamin D levels increased (quintile 5 versus 1, OR = 0.85, 95%CI: 0.55–1.30, P for trend = 0.076) after adjusting for potential confounders including age, sex, hypertension, diabetes, smoking status, and sunlight exposure times. The relative odds of DES (OR = 0.70, 95% CI: 0.30–1.64) and cataract (OR = 0.76, 95% CI: 0.59–0.99) were relatively high, while those of DR (OR = 0.37, 95% CI: 0.18–0.76) and late AMD (OR = 0.32, 95% CI: 0.12–0.81) were lower in men.

Conclusions

The present study does not support an association between serum 25-hydroxyvitamin D levels and DES. The preventive effect of serum 25-hydroxyvitamin D may be more effective for DR and late AMD than it is for cataract and DES.     

In Vitro Analysis of Metabolites Secreted during Infection of Lung Epithelial Cells by Cryptococcus neoformans

Cryptococcus neoformans is an encapsulated basidiomycetous yeast commonly associated with pigeon droppings and soil. The opportunistic pathogen infects humans through the respiratory system and the metabolic implications of C. neoformans infection have yet to be explored. Studying the metabolic profile associated with the infection could lead to the identification of important metabolites associated with pulmonary infection. Therefore, the aim of the study was to simulate cryptococcal infection at the primary site of infection, the lungs, and to identify the metabolic profile and important metabolites associated with the infection at low and high multiplicity of infections (MOI). The culture supernatant of lung epithelial cells infected with C. neoformans at MOI of 10 and 100 over a period of 18 hours were analysed using gas chromatography mass spectrometry. The metabolic profiles obtained were further analysed using multivariate analysis and the pathway analysis tool, MetaboAnalyst 2.0. Based on the results from the multivariate analyses, ten metabolites were selected as the discriminatory metabolites that were important in both the infection conditions. The pathways affected during early C. neoformans infection of lung epithelial cells were mainly the central carbon metabolism and biosynthesis of amino acids. Infection at a higher MOI led to a perturbance in the β-alanine metabolism and an increase in the secretion of pantothenic acid into the growth media. Pantothenic acid production during yeast infection has not been documented and the β-alanine metabolism as well as the pantothenate and CoA biosynthesis pathways may represent underlying metabolic pathways associated with disease progression. Our study suggested that β-alanine metabolism and the pantothenate and CoA biosynthesis pathways might be the important pathways associated with cryptococcal infection.     

Simple Scoring System and Artificial Neural Network for Knee Osteoarthritis Risk Prediction: A Cross-Sectional Study

Background

Knee osteoarthritis (OA) is the most common joint disease of adults worldwide. Since the treatments for advanced radiographic knee OA are limited, clinicians face a significant challenge of identifying patients who are at high risk of OA in a timely and appropriate way. Therefore, we developed a simple self-assessment scoring system and an improved artificial neural network (ANN) model for knee OA.

Methods

The Fifth Korea National Health and Nutrition Examination Surveys (KNHANES V-1) data were used to develop a scoring system and ANN for radiographic knee OA. A logistic regression analysis was used to determine the predictors of the scoring system. The ANN was constructed using 1777 participants and validated internally on 888 participants in the KNHANES V-1. The predictors of the scoring system were selected as the inputs of the ANN. External validation was performed using 4731 participants in the Osteoarthritis Initiative (OAI). Area under the curve (AUC) of the receiver operating characteristic was calculated to compare the prediction models.

Results

The scoring system and ANN were built using the independent predictors including sex, age, body mass index, educational status, hypertension, moderate physical activity, and knee pain. In the internal validation, both scoring system and ANN predicted radiographic knee OA (AUC 0.73 versus 0.81, p<0.001) and symptomatic knee OA (AUC 0.88 versus 0.94, p<0.001) with good discriminative ability. In the external validation, both scoring system and ANN showed lower discriminative ability in predicting radiographic knee OA (AUC 0.62 versus 0.67, p<0.001) and symptomatic knee OA (AUC 0.70 versus 0.76, p<0.001).

Conclusions

The self-assessment scoring system may be useful for identifying the adults at high risk for knee OA. The performance of the scoring system is improved significantly by the ANN. We provided an ANN calculator to simply predict the knee OA risk.     

Clinical relevance of glycerophospholipid,sphingomyelin and glutathione metabolism in the pathogenesis of pharyngolaryngeal cancer in smokers: the Korean Cancer Prevention Study-II

Introduction

Although smoking is a major risk factor for pharyngolaryngeal cancer, most smokers do not develop pharyngolaryngeal cancer.

Objectives

In the prospective Korean Cancer Prevention Study-II (KCPS-II), we investigated the application of metabolomics to differentiate smokers with incident pharyngolaryngeal cancer (pharyngolaryngeal cancer group) from smokers who remained free from cancer (controls) during a mean follow-up period of 7 years and aimed to discover valuable early biomarkers of pharyngolaryngeal cancer.

Methods

We used baseline serum samples from 30 smoking men with incident pharyngolaryngeal cancer and 59 age-matched cancer-free smoking men. Metabolic alterations associated with the incidence of pharyngolaryngeal cancer were investigated by performing metabolomics on baseline serum samples using ultra-performance liquid chromatography-linear-trap quadrupole-Orbitrap mass spectrometry.

Results

Compared to the control group, the pharyngolaryngeal cancer group showed significantly higher oxidized LDL levels. Seventeen metabolites were differentially abundant between the two groups. At baseline, compared to controls, smokers with incident pharyngolaryngeal cancer during follow-up showed significantly higher levels of pyroglutamic acid (glutathione metabolism) but lower levels of lysophosphatidylcholines (lysoPCs) C14:0, C15:0, C16:0, C17:0, C18:0, and C20:5; glycerophosphocholine; PC C36:5; lysoPEs C16:0, C20:1, and C22:0 (glycerophospholipid metabolism); SM (d18:0/16:1); and SM (d18:1/18:1) (sphingomyelin metabolism). Furthermore, smokers with incident pharyngolaryngeal cancer showed significantly higher levels of oleamide and lower levels of tryptophan and linoleyl carnitine at baseline than cancer-free smokers.

Conclusion

This prospective study showed the clinical relevance of dysregulated metabolism of glutathione, glycerophospholipids and sphingolipids to the pathogenesis of pharyngolaryngeal cancer among smokers. These data suggest that the dysregulation of these metabolic processes may be a key mechanism underlying pharyngolaryngeal cancer progression and development.

     

An Ultra‐Mechanosensitive Visco‐Poroelastic Polymer Ion Pump for Continuous Self‐Powering Kinematic Triboelectric Nanogenerators

A mechanosensitive, visco‐poroelastic polymer ion pump that can rapidly establish a dense electrical double layer via mechanical pressure, thereby significantly enhancing output performance of an ionic triboelectric nanogenerator (iTENG), is described. A working mechanism of an iTENG using a highly mechanosensitive, visco‐poroelastic ion pump is suggested and the optimal characteristics of the polymer ion pump are reported by investigating optical, mechanical, electrical, and electrochemical properties. Surprisingly, the pressure sensitivity of the iTENG reaches 23.3 V kPa^?1, which is tens of times the record value. To achieve controlled high‐frequency pulses from an iTENG, kinematic systems using a gear train and a cam are integrated with a single grounded iTENG, which produces a maximum of 600 V and 22 mA (≈2.2 W cm^?2) at an input frequency of 1.67 Hz; after power transforming, those values are converted to 1.42 V and 225 mA. A capacitor of 1 mF can be fully charged to 2 V in only 60 s, making it possible to continuously operate a wireless‐communicating self‐powered humidity sensor. Also, due to the high transparency and deformability of the polymer ion pump, a self‐powered transparent tactile sensor is successfully assembled using a 5 × 5 iTENG array.     

Cleaved Cochlin Sequesters Pseudomonas aeruginosa and Activates Innate Immunity in the Inner Ear

1. Download high-res image (269KB)
2. Download full-size image

     

Global genetic diversity,lineage distribution,and Wolbachia infection of the alfalfa weevil Hypera postica (Coleoptera: Curculionidae)

The alfalfa weevil (Hypera postica) is a well‐known example of a worldwide‐distributed pest with high genetic variation. Based on the mitochondrial genes, the alfalfa weevil clusters into two main mitochondrial lineages. However, there is no clear picture of the global diversity and distribution of these lineages; neither the drivers of its diversification are known. However, it appears likely that historic demographic events including founder effects played a role. In addition, Wolbachia, a widespread intracellular parasite/symbiont, likely played an important role in the evolution of the species. Wolbachia infection so far was only detected in the Western lineage of H. postica with no information on the infecting strain, its frequency, and its consequences on the genetic diversity of the host. We here used a combination of mitochondrial and nuclear sequences of the host and sequence information on Wolbachia to document the distribution of strains and the degree of infection. The Eastern lineage has a higher genetic diversity and is found in the Mediterranean, the Middle East, Eastern Europe, and eastern America, whereas the less diverse Western lineage is found in Central Europe and the western America. Both lineages are infected with the same common strain of Wolbachia belonging to Supergroup B. Based on neutrality tests, selection tests, and the current distribution and diversification of Wolbachia in H. postica, we suggested the Wolbachia infection did not shape genetic diversity of the host. The introduced populations in the United States are generally genetically less diverse, which is in line with founder effects.     

Phosphorylation of the endogenous thyrotropin-releasing hormone receptor in pituitary GH3 cells and pituitary tissue revealed by phosphosite-specific antibodies

To study phosphorylation of the endogenous type I thyrotropin-releasing hormone receptor in the anterior pituitary, we generated phosphosite-specific polyclonal antibodies. The major phosphorylation site of receptor endogenously expressed in pituitary GH3 cells was Thr(365) in the receptor tail; distal sites were more phosphorylated in some heterologous models. beta-Arrestin 2 reduced thyrotropin-releasing hormone (TRH)-stimulated inositol phosphate production and accelerated internalization of the wild type receptor but not receptor mutants where the critical phosphosites were mutated to Ala. Phosphorylation peaked within seconds and was maximal at 100 nm TRH. Based on dominant negative kinase and small interfering RNA approaches, phosphorylation was mediated primarily by G protein-coupled receptor kinase 2. Phosphorylated receptor, visualized by immunofluorescence microscopy, was initially at the plasma membrane, and over 5-30 min it moved to intracellular vesicles in GH3 cells. Dephosphorylation was rapid (t((1/2)) approximately 1 min) if agonist was removed while receptor was at the surface. Dephosphorylation was slower (t((1/2)) approximately 4 min) if agonist was withdrawn after receptor had internalized. After agonist removal and dephosphorylation, a second pulse of agonist caused extensive rephosphorylation, particularly if most receptor was still on the plasma membrane. Phosphorylated receptor staining was visible in prolactin- and thyrotropin-producing cells in rat pituitary tissue from untreated rats and much stronger in tissue from animals injected with TRH. Our results show that the TRH receptor can rapidly cycle between a phosphorylated and nonphosphorylated state in response to changing agonist concentrations and that phosphorylation can be used as an indicator of receptor activity in vivo.     

Transgenesis and nuclear transfer using porcine embryonic germ cells

Embryonic germ (EG) cells are undifferentiated stem cells isolated from cultured primordial germ cells (PGC). Porcine EG cell lines with capacities of both in vitro and in vivo differentiation have been established. Because EG cells can be cultured indefinitely in an undifferentiated state, they may be more suitable for nuclear donor cells in nuclear transfer (NT) than somatic cells that have limited lifespan in primary culture. Use of EG cells could be particularly advantageous to provide an inexhaustible source of transgenic cells for NT. In this study the efficiencies of transgenesis and NT using porcine fetal fibroblasts and EG cells were compared. The rate of development to the blastocyst stage was significantly higher in EG cell NT than somatic cell NT (94 of 518, 18.2% vs. 72 of 501, 14.4%). To investigate if EG cells can be used for transgenesis in pigs, green fluorescent protein (GFP) gene was introduced into porcine EG cells. Nuclear transfer embryos using transfected EG cells gave rise to blastocysts (29 of 137, 21.2%) expressing GFP based on observation under fluorescence microscope. The results obtained from the present study suggest that EG cell NT may have advantages over somatic cell NT, and transgenic pigs may be produced using EG cells.