Transfilter induction of kidney tubules: correlation with cytoplasmic penetration into Nucleopore filters

Development ◽  
1974 ◽  
Vol 31 (3) ◽  
pp. 667-682
Author(s):  
Jorma Wartiovaara ◽  
Stig Nordling ◽  
Eero Lehtonen ◽  
Lauri Saxén
Keyword(s):  
Spinal Cord ◽  
Pore Size ◽  
Long Range ◽  
Inverse Correlation ◽  
Membrane Vesicles ◽  
Cellular Interactions ◽  
Tubule Formation ◽  
Membrane Filters ◽  
Diffusion Rates ◽  
Transfilter Culture

The presence of cell contacts in transfilter mouse kidney tubule induction by spinal cord was investigated. The interacting tissues were separated by Nucleopore® membrane filters of various pore sizes. Filters with a mean pore size of 0·2 μm or more allowed tubule formation, whereas 0·13 μm pore filters prevented it. There was an inverse correlation between pore size and minimum time of transfilter culture required for induction to occur. The differences in the diffusion rates through these filters do not support long range diffusion as a mechanism for induction. Electron microscopy of the cultures showed abundant cytoplasmic penetration deep into filters with 0·2 μm or larger pores. Processes from mesenchymal and spinal cord cells were closely apposed within the filter channels. No extracellular matrix or membrane vesicles were seen between the processes. In a few instances shallow penetration was seen in 0·1 μm type filters, but no contacts were observed. The presence of close cell appositions in those filters which allow kidney tubulogenesis suggests that close cellular interactions, rather than long range diffusion of signal substances, is the most likely communicative mechanism in this transfilter induction.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

Assignment of carbonyl groups and sequence analysis in peptides by inverse correlation using long-range couplings

1987 ◽  
Vol 25 (4) ◽  
pp. 325-326 ◽  
Author(s):  
Wolfgang Bermel ◽  
Christian Griesinger ◽  
Horst Kessler ◽  
Klaus Wagner
Keyword(s):  
Sequence Analysis ◽  
Long Range ◽  
Inverse Correlation ◽  
Carbonyl Groups

scholarly journals Challenges in Fabrication of Tissue-Engineered Cartilage with Correct Cellular Colonization and Extracellular Matrix Assembly

2018 ◽  
Vol 19 (9) ◽  
pp. 2700 ◽  
Author(s):  
Mikko Lammi ◽  
Juha Piltti ◽  
Juha Prittinen ◽  
Chengjuan Qu
Keyword(s):  
Extracellular Matrix ◽  
Articular Cartilage ◽  
Pore Size ◽  
Cartilage Tissue ◽  
Cellular Interactions ◽  
Matrix Assembly ◽  
Small Pore ◽  
Culture Models ◽  
Open Question ◽  
Engineered Cartilage

A correct articular cartilage ultrastructure regarding its structural components and cellularity is important for appropriate performance of tissue-engineered articular cartilage. Various scaffold-based, as well as scaffold-free, culture models have been under development to manufacture functional cartilage tissue. Even decellularized tissues have been considered as a potential choice for cellular seeding and tissue fabrication. Pore size, interconnectivity, and functionalization of the scaffold architecture can be varied. Increased mechanical function requires a dense scaffold, which also easily restricts cellular access within the scaffold at seeding. High pore size enhances nutrient transport, while small pore size improves cellular interactions and scaffold resorption. In scaffold-free cultures, the cells assemble the tissue completely by themselves; in optimized cultures, they should be able to fabricate native-like tissue. Decellularized cartilage has a native ultrastructure, although it is a challenge to obtain proper cellular colonization during cell seeding. Bioprinting can, in principle, provide the tissue with correct cellularity and extracellular matrix content, although it is still an open question as to how the correct molecular interaction and structure of extracellular matrix could be achieved. These are challenges facing the ongoing efforts to manufacture optimal articular cartilage.

scholarly journals Chimeric rabies SADB19-VSVg-pseudotyped lentiviral vectors mediate long-range retrograde transduction from the mouse spinal cord

Gene Therapy ◽  
2015 ◽  
Vol 22 (5) ◽  
pp. 357-364 ◽  
Author(s):  
L Schoderboeck ◽  
S Riad ◽  
A M Bokor ◽  
H E Wicky ◽  
M Strauss ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Long Range ◽  
Lentiviral Vectors ◽  
Mouse Spinal Cord

scholarly journals Heterotopic ossification after central nervous system injuries: understanding of pathogenesis

2018 ◽  
Vol 25 (3-4) ◽  
pp. 119-124
Author(s):  
I. F Gareev ◽  
O. A Beylerli ◽  
A. K Vakhitov
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Heterotopic Ossification ◽  
Genetic Factors ◽  
Cellular Interactions ◽  
Heterotopic Ossifications ◽  
The Brain

Available data on the pathogenesis, cellular interactions, role of inflammation, humoral and genetic factors in the formation of heterotopic ossifications resulting from injuries of the brain or spinal cord are presented.

scholarly journals Conserved genetic signatures parcellate cardinal spinal neuron classes into local and projection subsets

Science ◽  
2021 ◽  
Vol 372 (6540) ◽  
pp. 385-393
Author(s):  
Peter J. Osseward ◽  
Neal D. Amin ◽  
Jeffrey D. Moore ◽  
Benjamin A. Temple ◽  
Bianca K. Barriga ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Long Range ◽  
Birth Date ◽  
Spinal Neuron ◽  
Top Down ◽  
Stepwise Manner ◽  
Neuronal Types ◽  
Genetic Signatures ◽  
Sensory Functions

Motor and sensory functions of the spinal cord are mediated by populations of cardinal neurons arising from separate progenitor lineages. However, each cardinal class is composed of multiple neuronal types with distinct molecular, anatomical, and physiological features, and there is not a unifying logic that systematically accounts for this diversity. We reasoned that the expansion of new neuronal types occurred in a stepwise manner analogous to animal speciation, and we explored this by defining transcriptomic relationships using a top-down approach. We uncovered orderly genetic tiers that sequentially divide groups of neurons by their motor-sensory, local-long range, and excitatory-inhibitory features. The genetic signatures defining neuronal projections were tied to neuronal birth date and conserved across cardinal classes. Thus, the intersection of cardinal class with projection markers provides a unifying taxonomic solution for systematically identifying distinct functional subsets.

scholarly journals Single-cell analysis of the cellular heterogeneity and interactions in the injured mouse spinal cord

2021 ◽  
Vol 218 (8) ◽  
Author(s):  
Lindsay M. Milich ◽  
James S. Choi ◽  
Christine Ryan ◽  
Susana R. Cerqueira ◽  
Sofia Benavides ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Single Cell ◽  
Single Cell Analysis ◽  
Healing Process ◽  
Cellular Heterogeneity ◽  
Wound Healing Process ◽  
Cellular Interactions ◽  
Mouse Spinal Cord ◽  
Cord Injury

The wound healing process that occurs after spinal cord injury is critical for maintaining tissue homeostasis and limiting tissue damage, but eventually results in a scar-like environment that is not conducive to regeneration and repair. A better understanding of this dichotomy is critical to developing effective therapeutics that target the appropriate pathobiology, but a major challenge has been the large cellular heterogeneity that results in immensely complex cellular interactions. In this study, we used single-cell RNA sequencing to assess virtually all cell types that comprise the mouse spinal cord injury site. In addition to discovering novel subpopulations, we used expression values of receptor–ligand pairs to identify signaling pathways that are predicted to regulate specific cellular interactions during angiogenesis, gliosis, and fibrosis. Our dataset is a valuable resource that provides novel mechanistic insight into the pathobiology of not only spinal cord injury but also other traumatic disorders of the CNS.

scholarly journals Modulation of neuroglial interactions using differential target multiplexed spinal cord stimulation in an animal model of neuropathic pain

2020 ◽  
Vol 16 ◽  
pp. 174480692091805 ◽  
Author(s):  
Ricardo Vallejo ◽  
Courtney A Kelley ◽  
Ashim Gupta ◽  
William J Smith ◽  
Alejandro Vallejo ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Animal Model ◽  
Neuropathic Pain ◽  
Nerve Injury ◽  
Spinal Cord Stimulation ◽  
High Rate ◽  
Biological Processes ◽  
Cellular Interactions ◽  
Neuroglial Interactions ◽  
Low Rate

The development and maintenance of chronic neuropathic pain involves distorted neuroglial interactions, which result in prolonged perturbations of immune and inflammatory response, as well as disrupted synapses and cellular interactions. Spinal cord stimulation (SCS) has proven effective and safe for more than 40 years, but comprehensive understanding of its mode of action remains elusive. Previous work in our laboratory provided evidence that conventional SCS parameters modulate biological processes associated with neuropathic pain in animals. This inspired the development of differential target multiplexed programming (DTMP) in which multiple electrical signals are used for modulating glial cells and neurons in order to rebalance their interactions. This work compares DTMP with both low rate and high rate programming using an animal model of neuropathic pain. The spared nerve injury model was implemented in 48 rats equally randomized into four experimental groups: No-SCS, DTMP, low rate, and high rate. Naive animals (N = 7) served as a reference control. SCS was applied continuously for 48 h and pain-related behavior assessed before and after SCS. RNA from the spinal cord exposed to SCS was sequenced to determine changes in gene expression as a result of injury (No-SCS vs. naïve) and as a result of SCS (SCS vs. No-SCS). Bioinformatics tools (Weighted Gene Co-expression Network Analysis and Gene Ontology Enrichment Analysis) were used to evaluate the significance of the results. All three therapies significantly reduced mechanical hypersensitivity, although DTMP provided statistically better results overall. DTMP also reduced thermal hypersensitivity significantly. RNA-sequencing corroborated the complex effects of nerve injury on the transcriptome. In addition, DTMP provided significantly more effective modulation of genes associated with pain-related processes in returning their expression toward levels observed in naïve, noninjured animals. DTMP provides a more effective way of modulating the expression of genes involved in pain-relevant biological processes associated with neuroglial interactions.

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