Traumatic spinal cord injury (SCI) initiates a cascade of cellular events, culminating in irreversible tissue loss and neuroinflammation. After the trauma, the blood vessels are destroyed. The blood-spinal cord barrier (BSCB), a physical barrier between the blood and spinal cord parenchyma, is disrupted, facilitating the infiltration of immune cells, and contributing to a toxic spinal microenvironment, affecting axonal regeneration.
View Article and Find Full Text PDFPersistent senescent cells (SCs) are known to underlie aging-related chronic disorders, but it is now recognized that SCs may be at the center of tissue remodeling events, namely during development or organ repair. In this study, we show that two distinct senescence profiles are induced in the context of a spinal cord injury between the regenerative zebrafish and the scarring mouse. Whereas induced SCs in zebrafish are progressively cleared out, they accumulate over time in mice.
View Article and Find Full Text PDFThe spinal cord dorsal horn is a major station for integration and relay of somatosensory information and comprises both excitatory and inhibitory neuronal populations. The homeobox gene Tlx3 acts as a selector gene to control the development of late-born excitatory (dILB) neurons by specifying glutamatergic transmitter fate in dorsal spinal cord. However, since Tlx3 direct transcriptional targets remain largely unknown, it remains to be uncovered how Tlx3 functions to promote excitatory cell fate.
View Article and Find Full Text PDFThe lysosome has a key role in the presentation of lipid antigens by CD1 molecules. While defects in lipid antigen presentation and in invariant Natural Killer T (iNKT) cell response were detected in several mouse models of lysosomal storage diseases (LSD), the impact of lysosomal engorgement in human lipid antigen presentation is poorly characterized. Here, we analyzed the capacity of monocyte-derived dendritic cells (Mo-DCs) from Fabry, Gaucher, Niemann Pick type C and Mucopolysaccharidosis type VI disease patients to present exogenous antigens to lipid-specific T cells.
View Article and Find Full Text PDFPeroxisomal matrix proteins are synthesized on cytosolic ribosomes and rapidly transported into the organelle by a complex machinery. The data gathered in recent years suggest that this machinery operates through a syringe-like mechanism, in which the shuttling receptor PEX5 - the "plunger" - pushes a newly synthesized protein all the way through a peroxisomal transmembrane protein complex - the "barrel" - into the matrix of the organelle. Notably, insertion of cargo-loaded receptor into the "barrel" is an ATP-independent process, whereas extraction of the receptor back into the cytosol requires its monoubiquitination and the action of ATP-dependent mechanoenzymes.
View Article and Find Full Text PDFA remarkable property of the machinery for import of peroxisomal matrix proteins is that it can accept already folded proteins as substrates. This import involves binding of newly synthesized proteins by cytosolic peroxisomal biogenesis factor 5 (PEX5) followed by insertion of the PEX5-cargo complex into the peroxisomal membrane at the docking/translocation module (DTM). However, how these processes occur remains largely unknown.
View Article and Find Full Text PDFProtease protection assays are powerful tools to determine the topology of organelle proteins. Their simplicity, together with the fact that they are particularly suited to characterize endogenous proteins, are their major advantages and the reason why these assays have been in use for so many years. Here, we provide a detailed protocol to use with mammalian peroxisomes.
View Article and Find Full Text PDFencodes for a paired-like homeodomain transcription factor essential for the correct establishment of the dorsal root ganglion - spinal cord nociceptive circuitry during development. -null mice display gross anatomical disruption of this circuitry, which translates to a markedly diminished sensitivity to noxious stimuli. Here, by the use of an immunoprecipitation and mass spectrometry approach, we identify five highly conserved phosphorylation sites (T110, S119, S231, S233 and S251) in PRRXL1 primary structure.
View Article and Find Full Text PDFHere we describe a protocol to dissect the peroxisomal matrix protein import pathway using a cell-free in vitro system. The system relies on a postnuclear supernatant (PNS), which is prepared from rat/mouse liver, to act as a source of peroxisomes and cytosolic components. A typical in vitro assay comprises the following steps: (i) incubation of the PNS with an in vitro-synthesized S-labeled reporter protein; (ii) treatment of the organelle suspension with a protease that degrades reporter proteins that have not associated with peroxisomes; and (iii) SDS-PAGE/autoradiography analysis.
View Article and Find Full Text PDFAntenatal betamethasone is used for accelerating fetal lung maturation for women at risk of preterm birth. Altered sperm parameters were reported in adult rats after intrauterine exposure to betamethasone. In this study, male rat offspring were assessed for reproductive development after dam exposure to betamethasone (0.
View Article and Find Full Text PDFBetamethasone is the drug of choice for antenatal treatment, promoting fetal lung maturation, decreasing the incidence of respiratory distress syndrome and neonatal mortality. Previous studies reported that prenatal treatment with this drug reduced testosterone levels, sperm quality and fertility in adult rats. We aimed to further evaluate the reproductive consequences of prenatal betamethasone exposure in male rats.
View Article and Find Full Text PDFBackground: Due to an abundance of repetitive DNA, the annotation of heterochromatic regions of the genome such as the Y chromosome is problematic. The Y chromosome is involved in key biological functions such as male-fertility and sex-determination and hence, accurate identification of its sequences is vital. The hemipteran insect Rhodnius prolixus is an important vector of Chagas disease, a trypanosomiasis affecting 6-7 million people worldwide.
View Article and Find Full Text PDFIn the field of intracellular protein sorting, peroxisomes are most famous by their capacity to import oligomeric proteins. The data supporting this remarkable property are abundant and, understandably, have inspired a variety of hypothetical models on how newly synthesized (cytosolic) proteins reach the peroxisome matrix. However, there is also accumulating evidence suggesting that many peroxisomal oligomeric proteins actually arrive at the peroxisome still as monomers.
View Article and Find Full Text PDFCarrageenans are highly sulphated galactans, well-known for their thermogelation properties which have been extensively exploited in food and cosmetics industry but poorly explored in the biomedicine field. In this study, we have assessed the in vitro and in vivo biocompatibility of κ-carrageenan hydrogels that have been explored for regenerative medicine and tissue engineering applications. The in vitro cytotoxicity of the materials using a L929 mouse fibroblast cell line was evaluated, and the effect of κ-carrageenan hydrogels on the activation of human polymorphonuclear neutrophils cells (hPMNs) was also evaluated by the quantification of reactive oxygen species by chemiluminescence.
View Article and Find Full Text PDFFabry disease is a lysosomal storage disease belonging to the group of sphingolipidoses. In Fabry disease there is accumulation of mainly globotriaosylceramide due to deficiency of the lysosomal enzyme α-galactosidase A. The lysosome is an important compartment for the activity of invariant natural killer T (iNKT) cells.
View Article and Find Full Text PDFTissue Eng Part C Methods
November 2012
The aim of this work was to study the effect of cryopreservation over the functionality of tissue-engineered constructs, analyzing the survival and viability of cells seeded, cultured, and cryopreserved onto 3D scaffolds. Further, it also evaluated the effect of cryopreservation over the properties of the scaffold material itself since these are critical for the engineering of most tissues and in particular, tissues such as bone. For this purpose, porous scaffolds, namely fiber meshes based on a starch and poly(caprolactone) blend were seeded with goat bone marrow stem cells (GBMSCs) and cryopreserved for 7 days.
View Article and Find Full Text PDFCase report of a patient with rheumatoid arthritis who developed severe neutropenia, splenomegaly and was diagnosed with Felty's syndrome. The patient later developed Kala-azar. Both diseases have similar clinical and laboratory presentation, making the differential diagnosis difficult.
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