SNARE Protein Mimicry by an Intracellular Bacterium

Many intracellular pathogens rely on host cell membrane compartments for their survival. The strategies they have developed to subvert intracellular trafficking are often unknown, and SNARE proteins, which are essential for membrane fusion, are possible targets. The obligate intracellular bacteria Chlamydia replicate within an intracellular vacuole, termed an inclusion. A large family of bacterial proteins is inserted in the inclusion membrane, and the role of these inclusion proteins is mostly unknown. Here we identify SNARE-like motifs in the inclusion protein IncA, which are conserved among most Chlamydia species. We show that IncA can bind directly to several host SNARE proteins. A subset of SNAREs is specifically recruited to the immediate vicinity of the inclusion membrane, and their accumulation is reduced around inclusions that lack IncA, demonstrating that IncA plays a predominant role in SNARE recruitment. However, interaction with the SNARE machinery is probably not restricted to IncA as at least another inclusion protein shows similarities with SNARE motifs and can interact with SNAREs. We modelled IncA's association with host SNAREs. The analysis of intermolecular contacts showed that the IncA SNARE-like motif can make specific interactions with host SNARE motifs similar to those found in a bona fide SNARE complex. Moreover, point mutations in the central layer of IncA SNARE-like motifs resulted in the loss of binding to host SNAREs. Altogether, our data demonstrate for the first time mimicry of the SNARE motif by a bacterium

Global and Regional Differences in Brain Anatomy of Young Children Born Small for Gestational Age

In children who are born small for gestational age (SGA), an adverse intrauterine environment has led to underdevelopment of both the body and the brain. The delay in body growth is (partially) restored during the first two years in a majority of these children. In addition to a negative influence on these physical parameters, decreased levels of intelligence and cognitive impairments have been described in children born SGA. In this study, we used magnetic resonance imaging to examine brain anatomy in 4- to 7-year-old SGA children with and without complete bodily catch-up growth and compared them to healthy children born appropriate for gestational age. Our findings demonstrate that these children strongly differ on brain organisation when compared with healthy controls relating to both global and regional anatomical differences. Children born SGA displayed reduced cerebral and cerebellar grey and white matter volumes, smaller volumes of subcortical structures and reduced cortical surface area. Regional differences in prefrontal cortical thickness suggest a different development of the cerebral cortex. SGA children with bodily catch-up growth constitute an intermediate between those children without catch-up growth and healthy controls. Therefore, bodily catch-up growth in children born SGA does not implicate full catch-up growth of the brain

Unravelling the relationship between animal growth and immune response during micro-parasitic infections

Background: Both host genetic potentials for growth and disease resistance, as well as nutrition are known to affect responses of individuals challenged with micro-parasites, but their interactive effects are difficult to predict from experimental studies alone. Methodology/Principal Findings: Here, a mathematical model is proposed to explore the hypothesis that a host's response to pathogen challenge largely depends on the interaction between a host's genetic capacities for growth or disease resistance and the nutritional environment. As might be expected, the model predicts that if nutritional availability is high, hosts with higher growth capacities will also grow faster under micro-parasitic challenge, and more resistant animals will exhibit a more effective immune response. Growth capacity has little effect on immune response and resistance capacity has little effect on achieved growth. However, the influence of host genetics on phenotypic performance changes drastically if nutrient availability is scarce. In this case achieved growth and immune response depend simultaneously on both capacities for growth and disease resistance. A higher growth capacity (achieved e.g. through genetic selection) would be detrimental for the animal's ability to cope with pathogens and greater resistance may reduce growth in the short-term. Significance: Our model can thus explain contradicting outcomes of genetic selection observed in experimental studies and provides the necessary biological background for understanding the influence of selection and/or changes in the nutritional environment on phenotypic growth and immune response. © 2009 Doeschl-Wilson et al

Eeyarestatin 1 interferes with both retrograde and anterograde intracellular trafficking pathways

Background: The small molecule Eeyarestatin I (ESI) inhibits the endoplasmic reticulum (ER)-cytosol dislocation and subsequent degradation of ERAD (ER associated protein degradation) substrates. Toxins such as ricin and Shiga/Shiga-like toxins (SLTx) are endocytosed and trafficked to the ER. Their catalytic subunits are thought to utilise ERAD-like mechanisms to dislocate from the ER into the cytosol, where a proportion uncouples from the ERAD process, recovers a catalytic conformation and destroys their cellular targets. We therefore investigated ESI as a potential inhibitor of toxin dislocation. Methodology and Principal Findings: Using cytotoxicity measurements, we found no role for ESI as an inhibitor of toxin dislocation from the ER, but instead found that for SLTx, ESI treatment of cells was protective by reducing the rate of toxin delivery to the ER. Microscopy of the trafficking of labelled SLTx and its B chain (lacking the toxic A chain) showed a delay in its accumulation at a peri-nuclear location, confirmed to be the Golgi by examination of SLTx B chain metabolically labelled in the trans-Golgi cisternae. The drug also reduced the rate of endosomal trafficking of diphtheria toxin, which enters the cytosol from acidified endosomes, and delayed the Golgi-specific glycan modifications and eventual plasma membrane appearance of tsO45 VSV-G protein, a classical marker for anterograde trafficking. Conclusions and Significance: ESI acts on one or more components that function during vesicular transport, whilst at least one retrograde trafficking pathway, that of ricin, remains unperturbed

Synthesis, chiral high performance liquid chromatographic resolution and enantiospecific activity of a potent new geranylgeranyl transferase inhibitor, 2-hydroxy-3-imidazo[1,2-a]pyridin-3-yl-2-phosphonopropionic acid.

3-(3-Pyridyl)-2-hydroxy-2-phosphonopropanoic acid (3-PEHPC, 1) is a phosphonocarboxylate (PC) analogue of 2-(3-pyridyl)-1-hydroxyethylidenebis(phosphonic acid) (risedronic acid, 2), an osteoporosis drug that decreases bone resorption by inhibiting farnesyl pyrophosphate synthase (FPPS) in osteoclasts, preventing protein prenylation. 1 has lower bone affinity than 2 and weakly inhibits Rab geranylgeranyl transferase (RGGT), selectively preventing prenylation of Rab GTPases. We report here the synthesis and biological studies of 2-hydroxy-3-imidazo[1,2-a]pyridin-3-yl-2-phosphonopropionic acid (3-IPEHPC, 3), the PC analogue of minodronic acid 4. Like 1, 3 selectively inhibited Rab11 vs. Rap 1A prenylation in J774 cells, and decreased cell viability, but was 33-60x more active in these assays. After resolving 3 by chiral HPLC (>98% ee), we found that (+)-3-E1 was much more potent than (-)-3-E2 in an isolated RGGT inhibition assay, approximately 17x more potent (LED 3 microM) than (-)-3-E2 in inhibiting Rab prenylation in J774 cells and >26x more active in the cell viability assay. The enantiomers of 1 exhibited a 4-fold or smaller potency difference in the RGGT and prenylation inhibition assays

Pain Education and Knowledge (PEAK) Consensus Guidelines for Neuromodulation: A Proposal for Standardization in Fellowship and Training Programs

Scott G Pritzlaff,1 Johnathan H Goree,2 Jonathan M Hagedorn,3 David W Lee,4 Kenneth B Chapman,5 Sandy Christiansen,6 Andrew Dudas,7 Alexander Escobar,8 Christopher J Gilligan,9 Maged Guirguis,10 Amitabh Gulati,11 Jessica Jameson,12 Christopher J Mallard,13 Melissa Murphy,14 Kiran V Patel,15 Raj G Patel,16 Samir J Sheth,17 Stephanie Vanterpool,18 Vinita Singh,19 Gregory Smith,2 Natalie H Strand,20 Chau M Vu,21 Tolga Suvar,22 Krishnan Chakravarthy,23 Leonardo Kapural,24 Michael S Leong,25 Timothy R Lubenow,22 Alaa Abd-Elsayed,26 Jason E Pope,21 Dawood Sayed,27 Timothy R Deer28 1Department of Anesthesiology and Pain Medicine, University of California, Davis, Sacramento, CA, USA; 2Department of Anesthesiology, University of Arkansas for Medical Sciences, Little Rock, AR, USA; 3Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Mayo Clinic, Rochester, MN, USA; 4Fullerton Orthopedic Surgery Medical Group, Fullerton, CA, USA; 5The Spine & Pain Institute of New York, New York, NY, USA; 6Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA; 7Mays & Schnapp Neurospine and Pain, Memphis, TN, USA; 8Department of Anesthesiology, University of Toledo, Toledo, OH, USA; 9Division of Pain Medicine, Brigham and Women’s Hospital Harvard Medical School, Boston, MA, USA; 10Division of Pain Management, Ochsner Health, New Orleans, LA, USA; 11Department of Anesthesiology and Critical Care, Memorial Sloan Kettering Cancer Center, New York, NY, USA; 12Axis Spine Center, Coeur D’Alene, ID, USA; 13Department of Anesthesiology, University of Kentucky, Lexington, KY, USA; 14North Texas Orthopedics and Spine Center, Grapevine, TX, USA; 15Department of Anesthesiology and Pain Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Northwell Health, Hempstead, NY, USA; 16Capitol Pain Institute, Austin, TX, USA; 17Interventional Pain Management, Sutter Health, Roseville, CA, USA; 18Department of Anesthesiology, University of Tennessee, Knoxville, TN, USA; 19Department of Anesthesiology, Emory University, Atlanta, GA, USA; 20Interventional Pain Management, Mayo Clinic, Scottsdale, AZ, USA; 21Evolve Restorative Center, Santa Rosa, CA, USA; 22Department of Anesthesiology and Pain Medicine, Rush University Medical Center, Chicago, IL, USA; 23Coastal Pain and Spinal Diagnostics Medical Group, San Diego, CA, USA; 24Carolinas Pain Institute, Winston-Salem, NC, USA; 25Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA, USA; 26Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; 27Department of Anesthesiology, Pain and Perioperative Medicine, University of Kansas, Kansas City, KS, USA; 28The Spine and Nerve Center of the Virginias, Charleston, WV, USACorrespondence: Scott G Pritzlaff, University of California, Davis, 4860 Y Street, Suite 3020, Sacramento, CA, 95817, USA, Tel +1 916 734-6824, Fax +1 916 734-6827, Email [email protected]: The need to be competent in neuromodulation is and should be a prerequisite prior to completing a fellowship in interventional pain medicine. Unfortunately, many programs lack acceptable candidates for these advanced therapies, and fellows may not receive adequate exposure to neuromodulation procedures. The American Society of Pain and Neuroscience (ASPN) desires to create a consensus of experts to set a minimum standard of competence for neurostimulation procedures, including spinal cord stimulation (SCS), dorsal root ganglion stimulation (DRG-S), and peripheral nerve stimulation (PNS). The executive board of ASPN accepted nominations for colleagues with excellence in the subject matter of neuromodulation and physician education. This diverse group used peer-reviewed literature and, based on grading of evidence and expert opinion, developed critical consensus guides for training that all accredited fellowship programs should adopt. For each consensus point, transparency and recusal were used to eliminate bias, and an author was nominated for evidence grading oversight and bias control. Pain Education and Knowledge (PEAK) Consensus Guidelines for Neuromodulation sets a standard for neuromodulation training in pain fellowship training programs. The consensus panel has determined several recommendations to improve care in the United States for patients undergoing neuromodulation. As neuromodulation training in the United States has evolved dramatically, these therapies have become ubiquitous in pain medicine. Unfortunately, fellowship programs and the Accreditation Council for Graduate Medical Education (ACGME) pain program requirements have not progressed training to match the demands of modern advancements. PEAK sets a new standard for fellowship training and presents thirteen practice areas vital for physician competence in neuromodulation.Keywords: neuromodulation, pain education, spinal cord stimulation, dorsal root ganglion stimulation, peripheral nerve stimulation, fellowship trainin