scholarly journals CgNa, a type I toxin from the giant Caribbean sea anemone Condylactis gigantea shows structural similarities to both type I and II toxins, as well as distinctive structural and functional properties1

2007 ◽  
Vol 406 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Emilio Salceda ◽  
Javier Pérez-Castells ◽  
Blanca López-Méndez ◽  
Anoland Garateix ◽  
Hector Salazar ◽  
...  
Keyword(s):  
Caribbean Sea ◽  
Structural Features ◽  
Sea Anemone ◽  
Dorsal Root Ganglion Neurons ◽  
Significant Shift ◽  
Type I ◽  
Characteristic Structure ◽  
Inactivation Curve ◽  
Surface Patches ◽  
Ganglion Neurons

CgNa (Condylactis gigantea neurotoxin) is a 47-amino-acid- residue toxin from the giant Caribbean sea anemone Condylactis gigantea. The structure of CgNa, which was solved by 1H-NMR spectroscopy, is somewhat atypical and displays significant homology with both type I and II anemone toxins. CgNa also displays a considerable number of exceptions to the canonical structural elements that are thought to be essential for the activity of this group of toxins. Furthermore, unique residues in CgNa define a characteristic structure with strong negatively charged surface patches. These patches disrupt a surface-exposed cluster of hydrophobic residues present in all anemone-derived toxins described to date. A thorough characterization by patch–clamp analysis using rat DRG (dorsal root ganglion) neurons indicated that CgNa preferentially binds to TTX-S (tetrodotoxin-sensitive) voltage-gated sodium channels in the resting state. This association increased the inactivation time constant and the rate of recovery from inactivation, inducing a significant shift in the steady state of inactivation curve to the left. The specific structural features of CgNa may explain its weaker inhibitory capacity when compared with the other type I and II anemone toxins.

Neuregulin isoforms in dorsal root ganglion neurons: Effects of the cytoplasmic domain on localization and membrane shedding of Nrg-1 type I

2006 ◽  
Vol 84 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Zhiyou Zhang ◽  
Lisa Prentiss ◽  
Deborah Heitzman ◽  
Richard C. Stahl ◽  
Frank DiPino ◽  
...  
Keyword(s):  
Dorsal Root Ganglion ◽  
Dorsal Root ◽  
Cytoplasmic Domain ◽  
Dorsal Root Ganglion Neurons ◽  
Type I ◽  
Ganglion Neurons ◽  
Membrane Shedding

Engineering Fiber-Based Nervous Tissue Constructs for Axon Regeneration

2021 ◽  
pp. 1-13
Author(s):  
Mevan L. Siriwardane ◽  
Kathleen Derosa ◽  
George Collins ◽  
Bryan J. Pfister
Keyword(s):  
Type I Collagen ◽  
Nerve Repair ◽  
Small Diameter ◽  
Axon Growth ◽  
Dorsal Root Ganglion Neurons ◽  
Type I ◽  
Adult Rats ◽  
Hydrogel Matrix ◽  
Ganglion Neurons

Biomaterial-based scaffolds used in nerve conduits including channels for confining regenerating axons and 3-dimensional (3D) gels as substrates for growth have made improvements in models of nerve repair. Many biomaterial strategies, however, continue to fall short of autologous nerve grafts, which remain the current gold standard in repairing severe nerve lesions (<20 mm). Intraluminal nerve conduit fibers have also shown considerable promise in directing regenerating axons in vitro and in vivo and have gained increasing interest for nerve repair. It is unknown, however, how growing axons respond to a fiber when encountered in a 3D environment. In this study, we considered a construct consisting of a compliant collagen hydrogel matrix and a fiber component to assess contact-guided axon growth. We investigated preferential axon outgrowth on synthetic and natural polymer fibers by utilizing small-diameter microfibers of poly-L-lactic acid and type I collagen representing 2 different fiber stiffnesses. We found that axons growing freely in a 3D hydrogel culture preferentially attach, turn and follow fibers with outgrowth rates and distances that far exceed outgrowth in a hydrogel alone. Wet-spun type I collagen from rat tail tendon performed the best, associated with highly aligned and accelerated outgrowth. This study also evaluated the response of dorsal root ganglion neurons from adult rats to provide data more relevant to axon regenerative potential in nerve repair. We found that ECM treatments on fibers enhanced the regeneration of adult axons indicating that both the physical and biochemical presentation of the fibers are essential for enhancing axon guidance and growth.

scholarly journals A New Method for Primary Culture of Mouse Dorsal Root Ganglion Neurons

2018 ◽  
Author(s):  
Tiantian Dong ◽  
Shigang Li ◽  
Wei Liu ◽  
Mengzhen Yan ◽  
Jie Yu ◽  
...  
Keyword(s):  
Dorsal Root Ganglion ◽  
Primary Culture ◽  
Dorsal Root ◽  
Neuron Specific Enolase ◽  
Dorsal Root Ganglion Neurons ◽  
Immunocytochemical Staining ◽  
Type I ◽  
Reliable Model ◽  
Mouse Dorsal Root Ganglion ◽  
Ganglion Neurons

AbstractIn order to establish a simple and highly purified method for primary culture of mouse dorsal root ganglion neurons(DRGn), in this study, the DRGn of young mice were obtained by collagenase type I and trypsin digestion. Then the DRGn were obtained by immunocytochemical staining of mouse neuron specific enolase (NSE) monoclonal antibody, while using flow cytometry to further detect the positive rates of DRGn. The cultured primary DRGn grew well and had a purity of about 83.72%. The DRGn survival time was 60 days when cultured in DMEM medium containing nerve growth factor (NGF). The culture scheme is simple and stable, and a large number of high purity DRGn could be cultured, which provides a reliable model for further study of nerve cells.

scholarly journals Failure to Upregulate the RNA Binding Protein ZBP After Injury Leads to Impaired Regeneration in a Rodent Model of Diabetic Peripheral Neuropathy

2021 ◽  
Vol 14 ◽  
Author(s):  
James I. Jones ◽  
Christopher J. Costa ◽  
Caitlin Cooney ◽  
David C. Goldberg ◽  
Matthew Ponticiello ◽  
...  
Keyword(s):  
Peripheral Neuropathy ◽  
Diabetic Peripheral Neuropathy ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Rodent Model ◽  
Dorsal Root Ganglion Neurons ◽  
Nerve Degeneration ◽  
Type I ◽  
Ganglion Neurons

Most diabetes patients eventually suffer from peripheral nerve degeneration. Unfortunately, there is no treatment for the condition and its mechanisms are not well understood. There is, however, an emerging consensus that the inability of peripheral nerves to regenerate normally after injury contributes to the pathophysiology. We have previously shown that regeneration of peripheral axons requires local axonal translation of a pool of axonal mRNAs and that the levels and members of this axonal mRNA pool are altered in response to injury. Here, we show that following sciatic nerve injury in a streptozotocin rodent model of type I diabetes, this mobilization of RNAs into the injured axons is attenuated and correlates with decreased axonal regeneration. This failure of axonal RNA localization results from decreased levels of the RNA binding protein ZBP1. Over-expression of ZBP1 rescues the in vitro growth defect in injured dorsal root ganglion neurons from diabetic rodents. These results provide evidence that decreased neuronal responsiveness to injury in diabetes is due to a decreased ability to alter the pool of axonal mRNAs available for local translation, and may open new therapeutic opportunities for diabetic peripheral neuropathy.

Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

1987 ◽  
Vol 45 ◽  
pp. 792-793
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
M.E. Lidstrom ◽  
C.C. Remsen
Keyword(s):  
Cytoplasmic Membrane ◽  
Structural Features ◽  
Methylotrophic Bacteria ◽  
Type I ◽  
Type Ii ◽  
Membrane Complex ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Wall Structures ◽  
Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

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