Biochemistry, Biophysics, and Structural Biology Commons^™

The Replication Initiator Of The Cholera Pathogen’S Second Chromosome Shows Structural Similarity To Plasmid Initiators, Natalia Orlova, Matthew Gerding, Olha Ivashkiv, Paul Dominic B. Olinares, Brian T. Chait, Matthew K. Waldor, David Jeruzalmi

Publications and Research

The conserved DnaA-oriC system is used to initiate replication of primary chromosomes throughout the bacterial kingdom; however, bacteria with multipartite genomes evolved distinct systems to initiate replication of secondary chromosomes. In the cholera pathogen, Vibrio cholerae, and in related species, secondary chromosome replication requires the RctB initiator protein. Here, we show that RctB consists of four domains. The structure of its central two domains resembles that of several plasmid replication initiators. RctB contains at least three DNA binding winged-helix-turn-helix motifs, and mutations within any of these severely compromise biological activity. In the structure, RctB adopts a headto- head dimeric configuration …

Hiv Glycoprotein Gp120 Impairs Fast Axonal Transport By Activating Tak1 Signaling Pathways, Sarah H. Berth, Nichole Mesnard-Hoaglin, Bin Wang, Hajwa Kim, Yuyu Song, Maria Sapar, Gerardo Morfini, Scott T. Brady

Publications and Research

Sensory neuropathies are the most common neurological complication of HIV. Of these, distal sensory polyneuropathy (DSP) is directly caused by HIV infection and characterized by length-dependent axonal degeneration of dorsal root ganglion (DRG) neurons. Mechanisms for axonal degeneration in DSP remain unclear, but recent experiments revealed that the HIV glycoprotein gp120 is internalized and localized within axons of DRG neurons. Based on these findings, we investigated whether intra-axonal gp120 might impair fast axonal transport (FAT), a cellular process critical for appropriate maintenance of the axonal compartment. Significantly, we found that gp120 severely impaired both anterograde and retrograde FAT. Providing a …

Ben Domain Protein Elba2 Can Functionally Substitute For Linker Histone H1 In Drosophila In Vivo, Na Xu, Xingwu Lu, Harsh Kavi, Alexander V. Emelyanov, Travis J. Bernardo, Elena Vershilova, Arthur I. Skoultchi, Dmitry V. Fyodorov

Publications and Research

Metazoan linker histones are essential for development and play crucial roles in organization of chromatin, modification of epigenetic states and regulation of genetic activity. Vertebrates express multiple linker histone H1 isoforms, which may function redundantly. In contrast, H1 isoforms are not present in Dipterans, including D. melanogaster, except for an embryo-specific, distantly related dBigH1. Here we show that Drosophila BEN domain protein Elba2, which is expressed in early embryos and was hypothesized to have insulator-specific functions, can compensate for the loss of H1 in vivo. Although the Elba2 gene is not essential, its mutation causes a disruption of normal internucleosomal …

Implementing An Mhealth System For Substance Use Disorders In Primary Care: A Mixed Methods Study Of Clinicians’ Initial Expectations And First Year Experiences, Marie-Louise Mares, David H. Gustafson, Joseph E. Glass, Andrew Quanbeck, Helene Mcdowell, Fiona Mctavish, Amy K. Atwood, Lisa A. Marsch, Chanetelle Thomas, Dhavan Shah, Randall Brown, Andrew Isham, Mary Jane Nealon, Victoria Ward

Publications and Research

Background: Millions of Americans need but don’t receive treatment for substance use, and evidence suggests that addiction-focused interventions on smart phones could support their recovery. There is little research on implementation of addiction-related interventions in primary care, particularly in Federally Qualified Health Centers (FQHCs) that provide primary care to underserved populations. We used mixed methods to examine three FQHCs’ implementation of Seva, a smart-phone app that offers patients online support/discussion, health-tracking, and tools for coping with cravings, and offers clinicians information about patients’ health tracking and relapses. We examined (a) clinicians’ initial perspectives about implementing Seva, and (b) the first …

Fhf-Independent Conduction Of Action Potentials Along The Leak-Resistant Cerebellar Granule Cell Axon, Katarzyna Dover, Christopher Marra, Sergio Solinas, Marko Popovic, Sathyaa Subramaniyam, Dejan Zecevic, Egidio D'Angelo, Mitchell Goldfarb

Publications and Research

Neurons in vertebrate central nervous systems initiate and conduct sodium action potentials in distinct subcellular compartments that differ architecturally and electrically. Here, we report several unanticipated passive and active properties of the cerebellar granule cell’s unmyelinated axon. Whereas spike initiation at the axon initial segment relies on sodium channel (Nav)-associated fibroblast growth factor homologous factor (FHF) proteins to delay Nav inactivation, distal axonal Navs show little FHF association or FHF requirement for high-frequency transmission, velocity and waveforms of conducting action potentials. In addition, leak conductance density along the distal axon is estimated as o1% that of somatodendritic membrane. The faster …

Nmr And Structural Data For Connexin 32 And Connexin 26 N-Terminal Peptides, Yuskel Batir, Thaddeus A. Bargiello, Terry L. Dowd

Publications and Research

In this article we present 1H and 13C chemical shift assignments, secondary structural propensity data and normalized temperature coefficient data for N-terminal peptides of Connexin 26(Cx26), Cx26G12R and Cx32G12R mutants seen in syndromic deafness and Charcot Marie Tooth Disease respectively, published in “Structural Studies of N-Terminal Mutants of Connexin 26 and Connexin 32 Using 1HNMR Spectroscopy” (Y.Batir,T.A.Bargiello,T.L.Dowd, 2016)[1]. The mutation G12R affects thestructure of both Cx26 and Cx32 peptides differently. We present data from secondary structure propensity chemical shift analysis which calculates a secondary structurepropensity (SSP) score for both disordered or folded peptides and proteins using the difference between the …

Insights Into The Molecular Roles Of Heparan Sulfate Proteoglycans (Hspgs-Syndecans) In Autocrine And Paracrine Growth Factor Signaling In The Pathogenesis Of Hodgkin's Lymphoma, Rajendra Ghardbaran

Publications and Research

Syndecans (SDC, SYND) comprise a group of four structurally related type 1 transmembrane heparan sulfate proteoglycans (HSPGs) that play important roles in tumorigenic processes. SDCs exert signaling via their protein cores and their conserved transmembrane and cytoplasmic domains or by forming complexes with growth factors (GFs). In classical Hodgkin's lymphoma (cHL), a lymphoid neoplasm of predominantly B cell origin, SDC1 and SDC4 are the active SDCs, and a number of GF (vascular endothelial growth factor, fibroblast growth factor, etc.) signaling pathways have been studied. However, despite extensive pre-clinical and clinical research on SDC-mediated GF signaling in many cancer types, there …

Single-Nucleotide Polymorphisms And Markers Of Oxidative Stress In Healthy Women, Albina N. Minlikeeva, Richard W. Browne, Heather M. Ochs-Balcom, Catalin Marian, Peter G. Shields, Maurizio Trevisan, Shiva Krishnan, Ramakrishna Modali, Michael Seddon, Terese Lehman, Jo L. Freudenheim

Publications and Research

Purpose There is accumulating evidence that oxidative stress is an important contributor to carcinogenesis. We hypothesized that genetic variation in genes involved in maintaining antioxidant/ oxidant balance would be associated with overall oxidative stress.

Methods We examined associations between single nucleotide polymorphisms (SNPs) in MnSOD, GSTP1, GSTM1, GPX1, GPX3, and CAT genes and thiobarbituric acid-reactive substances (TBARS), a blood biomarker of oxidative damage, in healthy white women randomly selected from Western New York (n = 1402). We used general linear models to calculate age-adjusted geometric means of TBARS across the variants. We also examined the associations within strata of menopausal …

Antioxidant And Hepatoprotective Effects Of Procyanidins Fromwild Grape (Vitis Amurensis) Seeds In Ethanol-Induced Cells And Rats, Min Ji Bak, Van-Long Truong, Se-Yeon Ko, Xuan Ngan Giang Nguyen, Pajaree Ingkasupart, Mira Jun, Jin Young Shin, Woo-Sik Jeong

Publications and Research

In the present study, we characterized the antioxidant and hepatoprotective mechanisms underlying of wild grape seed procyanidins (WGP) against oxidative stress damage in ethanol-treated HepG2 cell and Sprague-Dawley (SD)-rat models. In HepG2 cells, WGP not only diminished the ethanol (EtOH, 100 mM)-induced reactive oxygen species (ROS) formation and cytochrome P450 2E1 (CYP2E1) expression, but also renovated both the activity and expression of antioxidant enzymes including catalase, superoxide dismutase, and glutathione peroxidase. Additionally, to investigate the hepatoprotective effect of WGP, rats were orally administered 10 or 50 mg/kg WGP once daily for seven days prior to the single oral administration of …

Molecular Self-Assembly Strategy For Generating Catalytic Hybrid Polypeptides, Yoshiaki Maeda, Justin Fang, Yasuhiro Ikezoe, Douglas H. Pike, Vikas Nanda, Hiroshi Matsui

Publications and Research

Recently, catalytic peptides were introduced that mimicked protease activities and showed promising selectivity of products even in organic solvents where protease cannot perform well. However, their catalytic efficiency was extremely low compared to natural enzyme counterparts presumably due to the lack of stable tertiary fold. We hypothesized that assembling these peptides along with simple hydrophobic pockets, mimicking enzyme active sites, could enhance the catalytic activity. Here we fused the sequence of catalytic peptide CP4, capable of protease and esterase-like activities, into a short amyloidogenic peptide fragment of Aβ. When the fused CP4-Aβ construct assembled into antiparallel β- sheets and amyloid …

From Mollusks To Medicine: A Venomics Approach For The Discovery And Characterization Of Therapeutics From Terebridae Peptide Toxins, Aida Verdes, Prachi Anand, Juliette Gorson, Stephen Jannetti, Patrick Kelly, Abba Leffler, Danny Simpson, Girish Ramrattan, Mandë Holford

Publications and Research

Animal venoms comprise a diversity of peptide toxins that manipulate molecular targets such as ion channels and receptors, making venom peptides attractive candidates for the development of therapeutics to benefit human health. However, identifying bioactive venom peptides remains a significant challenge. In this review we describe our particular venomics strategy for the discovery, characterization, and optimization of Terebridae venom peptides, teretoxins. Our strategy reflects the scientific path from mollusks to medicine in an integrative sequential approach with the following steps: (1) delimitation of venomous Terebridae lineages through taxonomic and phylogenetic analyses; (2) identification and classification of putative teretoxins through omics …

Integrated Systems Biology Analysis Of Transcriptomes Reveals Candidate Genes For Acidity Control In Developing Fruits Of Sweet Orange (Citrus Sinensis L. Osbeck), Dingquang Huang, Yihong Zhao, Minghao Cao, Liang Qiao, Zhi-Liang Zheng

Publications and Research

Organic acids, such as citrate and malate, are important contributors for the sensory traits of fleshy fruits. Although their biosynthesis has been illustrated, regulatory mechanisms of acid accumulation remain to be dissected. To provide transcriptional architecture and identify candidate genes for citrate accumulation in fruits, we have selected for transcriptome analysis four varieties of sweet orange (Citrus sinensis L. Osbeck) with varying fruit acidity, Succari (acidless), Bingtang (low acid), and Newhall and Xinhui (normal acid). Fruits of these varieties at 45 days post anthesis (DPA), which corresponds to Stage I (cell division), had similar acidity, but they displayed differential acid …

Discovery And Characterisation Of A Novel Toxin From Dendroaspis Angusticeps, Named Tx7335, That Activates The Potassium Channel Kcsa, Ivan O. Rivera-Torres, Tony B. Jin, Martine Cadene, Brian T. Chait, Sébastien F. Poget

Publications and Research

Due to their central role in essential physiological processes, potassium channels are common targets for animal toxins. These toxins in turn are of great value as tools for studying channel function and as lead compounds for drug development. Here, we used a direct toxin pull-down assay with immobilised KcsA potassium channel to isolate a novel KcsA-binding toxin (called Tx7335) from eastern green mamba snake (Dendroaspis angusticeps) venom. Sequencing of the toxin by Edman degradation and mass spectrometry revealed a 63 amino acid residue peptide with 4 disulphide bonds that belongs to the three-finger toxin family, but with a unique modification …

Engineered Protein Polymer-Gold Nanoparticle Hybrid Materials For Small Molecule Delivery, Min Dai, Ja Frezzo, E Sharma, R Chen, N Singh, C Yuvienco, E Caglar, S Xiao, A Saxena, Jk Montclare

Publications and Research

We have fabricated protein polymer-gold nanoparticle (P-GNP) nanocomposites that exhibit enhanced binding and delivery properties of the small hydrophobic molecule drug, curcumin, to the model breast cancer cell line, MCF-7. These hybrid biomaterials are constructed via in situ GNP templated-synthesis with genetically engineered histidine tags. The P-GNP nanocomposites exhibit enhanced small molecule loading, sustained release and increased uptake by MCF-7 cells. When compared to the proteins polymers alone, the P-GNPs demonstrate a greater than 7-fold increase in curcumin binding, a nearly 50% slower release profile and more than 2-fold increase in cellular uptake of curcumin. These results suggest that P-GNP …

Site-Specifically Labeled Immunoconjugates For Molecular Imaging—Part 1: Cysteine Residues And Glycans, Pierre Adumeau, Sai Kiran Sharma, Colleen Brent, Brian M. Zeglis

Publications and Research

Due to their remarkable selectivity and specificity for cancer biomarkers, immunoconjugates have emerged as extremely promising vectors for the delivery of diagnostic radioisotopes and fluorophores to malignant tissues. Paradoxically, however, these tools for precision medicine are synthesized in a remarkably imprecise way. Indeed, the vast majority of immunoconjugates are created via the random conjugation of bifunctional probes (e.g., DOTA-NCS) to amino acids within the antibody (e.g., lysines). Yet antibodies have multiple copies of these residues throughout their macromolecular structure, making control over the location of the conjugation reaction impossible. This lack of site specificity can lead to the formation of …

Characterization Of Fluorescent Proteins For Three- And Four-Color Live-Cell Imaging In S. Cerevisiae, Ryo Higuchi-Sanabria, Enrique J. Garcia, Delia Tomoiaga, Emilia L. Munteanu, Paul Feinstein, Liza A. Pon

Publications and Research

Saccharomyces cerevisiae are widely used for imaging fluorescently tagged protein fusions. Fluorescent proteins can easily be inserted into yeast genes at their chromosomal locus, by homologous recombination, for expression of tagged proteins at endogenous levels. This is especially useful for incorporation of multiple fluorescent protein fusions into a single strain, which can be challenging in organisms where genetic manipulation is more complex. However, the availability of optimal fluorescent protein combinations for 3-color imaging is limited. Here, we have characterized a combination of fluorescent proteins, mTFP1/mCitrine/ mCherry for multicolor live cell imaging in S. cerevisiae. This combination can be used with …

Cladribine Analogues Via O6-(Benzotriazolyl) Derivatives Of Guanine Nucleosides, Sakilam Satishkumar, Prasanna K. Vuram, Siva Subrahmanyam Relangi, Venkateshwarlu Gurram, Hong Zhou, Robert J. Kreitman, Michelle M. Martínez Montemayor, Lijia Yang, Muralidharan Kaliyaperumal, Somesh Sharma, Narender Pottabathini, Mahesh K. Lakshman

Publications and Research

Cladribine, 2-chloro-2′-deoxyadenosine, is a highly efficacious, clinically used nucleoside for the treatment of hairy cell leukemia. It is also being evaluated against other lymphoid malignancies and has been a molecule of interest for well over half a century. In continuation of our interest in the amide bond-activation in purine nucleosides via the use of (benzotriazol-1yl-oxy)tris(dimethylamino)phosphonium hexafluorophosphate, we have evaluated the use of O6-(benzotriazol-1-yl)-2′-deoxyguanosine as a potential precursor to cladribine and its analogues. These compounds, after appropriate deprotection, were assessed for their biological activities, and the data are presented herein. Against hairy cell leukemia (HCL), T-cell lymphoma (TCL) and chronic lymphocytic …

Two Distinct Modes Of Metal Ion Binding In The Nuclease Active Site Of A Viral Dna-Packaging Terminase: Insight Into The Two-Metal-Ion Catalytic Mechanism, Haiyan Zhao, Zihan Lin, Anna Y. Lynn, Brittany Varnado, John A. Beutler, Ryan P. Murelli, Stuart F.J. Le Grice, Liang Tang

Publications and Research

Many dsDNA viruses encode DNA-packaging terminases, each containing a nuclease domain that resolves concatemeric DNA into genome-length units. Terminase nucleases resemble the RNase H-superfamily nucleotidyltransferases in folds, and share a two-metal-ion catalytic mechanism. Here we show that residue K428 of a bacteriophage terminase gp2 nuclease domain mediates binding of the metal cofactor Mg2+. A K428A mutation allows visualization, at high resolution, of a metal ion binding mode with a coupled-octahedral configuration at the active site, exhibiting an unusually short metal-metal distance of 2.42 A° . Such proximity of the two metal ions may play an essential role in catalysis by …

Short Peptides In Minimalistic Biocatalyst Design, Krystyna L. Duncan, Rein V. Ulijn

Publications and Research

We review recent developments in the use of short peptides in the design of minimalistic biocatalysts focusing on ester hydrolysis. A number of designed peptide nanostructures are shown to have (modest) catalytic activity. Five features are discussed and illustrated by literature examples, including primary peptide sequence, nanosurfaces/scaffolds, binding pockets, multivalency and the presence of metal ions. Some of these are derived from natural enzymes, but others, such as multivalency of active sites on designed nanofibers, may give rise to new features not found in natural enzymes. Remarkably, it is shown that each of these design features give rise to similar …

Interferon-Γ Regulates Cellular Metabolism And Mrna Translation To Potentiate Macrophage Activation, Xiaodi Su, Yingpu Yu, Yi Zhong, Eugenia Giannopoulou, Xiaoyu Hu, Hui Liu, Justin R. Cross, Gunnar Rätsch, Charles M. Rice, Lionel B. Ivashkiv

Publications and Research

Interferon-γ (IFN-γ) primes macrophages for enhanced inflammatory activation by Toll-like receptors (TLRs) and microbial killing, but little is known about the regulation of cell metabolism or mRNA translation during priming. We found that IFN-γ regulates human macrophage metabolism and translation by targeting the kinases mTORC1 and MNK that both converge on the selective regulator of translation initiation eIF4E. Physiological downregulation of mTORC1 by IFN-γ was associated with autophagy and translational suppression of repressors of inflammation such as HES1. Genome-wide ribosome profiling in TLR2-stimulated macrophages revealed that IFN-γ selectively modulates the macrophage translatome to promote inflammation, further reprogram metabolic pathways, and …

The Hosoya Entropy Of A Graph, Abbe Mowshowitz, Matthias Dehmer

Publications and Research

This paper demonstrates properties of Hosoya entropy, a quantitative measure of graph complexity based on a decomposition of the vertices linked to partial Hosoya polynomials. Connections between the information content of a graph and Hosoya entropy are established, and the special case of Hosoya entropy of trees is investigated.

Protein Sectors: Statistical Coupling Analysis Versus Conservation, Tiberiu Teşileanu, Lucy J. Colwell, Stanislas Leibler

Publications and Research

Statistical coupling analysis (SCA) is a method for analyzing multiple sequence alignments that was used to identify groups of coevolving residues termed “sectors”. The method applies spectral analysis to a matrix obtained by combining correlation information with sequence conservation. It has been asserted that the protein sectors identified by SCA are functionally significant, with different sectors controlling different biochemical properties of the protein. Here we reconsider the available experimental data and note that it involves almost exclusively proteins with a single sector. We show that in this case sequence conservation is the dominating factor in SCA, and can alone be …

Nosh-Aspirin (Nbs-1120), A Dual Nitric Oxide And Hydrogen Sulfide-Releasing Hybrid, Reduces Inflammatory Pain, Miriam D. Fonseca, Fernando Q. Cunha, Khosrow Kashfi, Thiago M. Cunha

Publications and Research

The development of nitric oxide (NO)- and hydrogen sulfide (H2S)-releasing nonsteroidal anti-inflammatory drugs (NSAIDs) has generated more potent anti-inflammatory drugs with increased safety profiles. A new hybrid molecule incorporating both NO and H2S donors into aspirin (NOSH-aspirin) was recently developed. In the present study, the antinociceptive activity of this novel molecule was compared with aspirin in different models of inflammatory pain. It was found that NOSH-aspirin inhibits acetic acid-induced writhing response and carrageenan (Cg)-induced inflammatory hyperalgesia in a dosedependent (5–150 lmol/kg, v.o.) manner, which was superior to the effect of the same doses of aspirin. NOSH-aspirin’s antinociceptive effect was also …

Deriving High-Resolution Protein Backbone Structure Propensities From All Crystal Data Using The Information Maximization Device, Armando D. Solis

Publications and Research

The most informative probability distribution functions (PDFs) describing the Ramachandran phi-psi dihedral angle pair, a fundamental descriptor of backbone conformation of protein molecules, are derived from high-resolution X-ray crystal structures using an information-theoretic approach. The Information Maximization Device (IMD) is established, based on fundamental information-theoretic concepts, and then applied specifically to derive highly resolved phi-psi maps for all 20 single amino acid and all 8000 triplet sequences at an optimal resolution determined by the volume of current data. The paper shows that utilizing the latent information contained in all viable high-resolution crystal structures found in the Protein Data Bank (PDB), …

Spatial Gaussian Markov Random Fields: Modelling, Applications And Efficient Computations, Yu Ryan Yue, Xiao-Feng Wang

Publications and Research

A powerful modelling tool for spatial data is the framework of Gaussian Markov random fields (GMRFs), which are discrete domain Gaussian random fields equipped with a Markov property. GMRFs allow us to combine the analytical results for the Gaussian distribution as well as Markov properties, thus allow for the development of computationally efficient algorithms. Here we briefly review popular spatial GMRFs, show how to construct them, and outline their recent developments and possible future work.

Effects Of Water Availability And Pest Pressures On Tea (Camellia Sinensis) Growth And Functional Quality, Selena Ahmed, Colin M. Orians, Timothy S. Griffin, Sarabeth Buckley, Uchenna Unachukwu, Anne Elise Stratton, John Richard Stepp, Albert Robbat Jr, Sean Cash, Edward J. Kennelly

Publications and Research

Extreme shifts in water availability linked to global climate change are impacting crops worldwide. The present study examines the direct and interactive effects of water availability and pest pressures on tea (Camellia sinensis; Theaceae) growth and functional quality. Manipulative greenhouse experiments were used to measure the effects of variable water availability and pest pressures simulated by jasmonic acid (JA) on tea leaf growth and secondary metabolites that determine tea quality. Water treatments were simulated to replicate ideal tea growing conditions and extreme precipitation events in tropical southwestern China, a major centre of tea production. Results show that higher water availability …

Β2 Adrenergic Receptor Fluorescent Protein Fusions Traffic To The Plasma Membrane And Retain Functionality, Jaclyn Bubnell, Patrick Pfister, Maria L. Sapar, Matthew E. Rogers, Paul Feinstein

Publications and Research

Green fluorescent protein (GFP) has proven useful for the study of protein interactions and dynamics for the last twenty years. A variety of new fluorescent proteins have been developed that expand the use of available excitation spectra. We have undertaken an analysis of seven of the most useful fluorescent proteins (XFPs), Cerulean (and mCerulean3), Teal, GFP, Venus, mCherry and TagRFP657, as fusions to the archetypal G-protein coupled receptor, the β2 adrenergic receptor (β2AR). We have characterized these β2AR::XFP fusions in respect to membrane trafficking and G-protein activation. We noticed that in the mouse neural cell line, OP 6, that membrane …

Serine Proteolytic Pathway Activation Reveals An Expanded Ensemble Of Wound Response Genes In Drosophila, Rachel A. Patterson, Michelle T. Juarez, Anita Hermann, Roman Sasik, Gary Hardiman, William Mcginnis

Publications and Research

After injury to the animal epidermis, a variety of genes are transcriptionally activated in nearby cells to regenerate the missing cells and facilitate barrier repair. The range and types of diffusible wound signals that are produced by damaged epidermis and function to activate repair genes during epidermal regeneration remains a subject of very active study in many animals. In Drosophila embryos, we have discovered that serine protease function is locally activated around wound sites, and is also required for localized activation of epidermal repair genes. The serine protease trypsin is sufficient to induce a striking global epidermal wound response without …

Isoflurane Increases Neuronal Cell Death Vulnerability By Downregulating Mir-214, Hailiang Yan, Tao Xu, Hongfeng Zhao, Kuo-Chieh Lee, Hoau-Yan Wang, Yan Zhang

Publications and Research

Since accumulating evidence suggests the application of anesthetics may increase the risk of Alzheimer’s disease (AD), we investigated the cytotoxicity of inhaled general anesthesia in neurons and its underlying mechanism. Using primary cultured rat hippocampal neurons as the study model, here we show that isoflurane increases vulnerability to intracellular or extracellular amyloid b with or without serum deprivation. This isoflurane-induced effect is mediated by the downregulation of miR-214 level that lead to an elevated expression of Bax, a prominent target for miR-214. We conclude that isoflurane increases cell death in the presence of amyloid b by increasing Bax level through …

Autophagy Plays An Essential Role In Mediating Regression Of Hypertrophy During Unloading Of The Heart, Nirmala Hariharan, Yoshiyuki Ikeda, Chull Hong, Ralph R. Alcendor, Soichiro Usui, Shumin Gao, Yasuhiro Maejima, Junichi Sadoshima

Publications and Research

Autophagy is a bulk degradation mechanism for cytosolic proteins and organelles. The heart undergoes hypertrophy in response to mechanical load but hypertrophy can regress upon unloading. We hypothesize that autophagy plays an important role in mediating regression of cardiac hypertrophy during unloading. Mice were subjected to transverse aortic constriction (TAC) for 1 week, after which the constriction was removed (DeTAC). Regression of cardiac hypertrophy was observed after DeTAC, as indicated by reduction of LVW/BW and cardiomyocyte cross-sectional area. Indicators of autophagy, including LC3-II expression, p62 degradation and GFP-LC3 dots/cell, were significantly increased after DeTAC, suggesting that autophagy is induced. Stimulation …