Biology subjects

Woelfle, S.

Publications and source records attributed to Woelfle, S..

3 recordsLinked to original sources

bioRxiv2022

CLARITY increases sensitivity and specificity of fluorescence immunostaining in long-term archived human brain tissue

Immunohistochemistry on archival human brains is often limited because several conditions arise that complicate the use for high-resolution fluorescence microscopy. In this study, we developed a novel clearing approach for immunofluorescence-based analysis of perfusion- and immersion-fixed post mortem human brain tissue, termed hCLARITY. hCLARITY is optimized for specificity by reducing off-target labeling and yields very sensitive stainings in human brain sections allowing for super-resolution microscopy with unprecedented imaging of pre- and postsynaptic compartments. Moreover, hallmarks of the Alzheimers disease were preserved with hCLARITY, and importantly classical DAB or Nissl stainings are compatible with this protocol. hCLARITY is extremely versatile as demonstrated by the use of more than 30 well performing antibodies and allows for de- and subsequent re-staining of the same tissue section, which is important for multi-labelling approaches, e.g., in super-resolution microscopy. Taken together, hCLARITY enables research of the human brain with highest sensitivity and down to sub-diffraction resolution and therefore has enormous potential for the investigation of local morphological changes, e.g., in neurodegenerative diseases. Striking Image / Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/489700v1_ufig1.gif" ALT="Figure 1"> View larger version (79K): org.highwire.dtl.DTLVardef@1732df2org.highwire.dtl.DTLVardef@cda615org.highwire.dtl.DTLVardef@152b44aorg.highwire.dtl.DTLVardef@ba972a_HPS_FORMAT_FIGEXP M_FIG Summary of the main advantages of hCLARITY. CLARITY was applied on human post mortem brain tissue in direct comparison to untreated sections (minus CLARITY). Owing to removal of lipids during the clearing with SDS and the resulting reduction in light scattering, cleared sections were less opaque. The denaturing effect of the detergent SDS most likely results in better accessibility of certain epitopes. The major benefits of hCLARITY were found in an increased sensitivity and specificity of antibodies for neuronal cells. The adapted hCLARITY protocol is compatible with staining techniques for confocal microscopy, super-resolution microscopy, and light microscopy. C_FIG

neuroscience↗

bioRxiv2021

Interleukin-13 and its receptor are synaptic proteins involved in plasticity and neuroprotection

Immune system molecules are expressed by neurons, often for unknown functions. We have identified IL-13 and its receptor IL-13Ra1 as neuronal, synaptic proteins in mouse, rat, and human brains, whose engagement upregulates the phosphorylation of NMDAR and AMPAR subunits and, in turn, increases synaptic activity and CREB-mediated transcription. We demonstrate that increased IL-13 is a hallmark of traumatic brain injury (TBI) in mice as well as in two distinct cohorts of human patients. We also provide evidence that IL-13 upregulation protects neurons from excitotoxic death. We show IL-13 upregulation occurring in several cohorts of human brain samples and in CSF. Thus, IL-13 is a previously unrecognized physiological modulator of synaptic physiology of neuronal origin, with implications for the establishment of synaptic plasticity and the survival of neurons under injury conditions. Furthermore, we suggest that the neuroprotection afforded through the upregulation of IL-13 represents a new entry point for interventions in the pathophysiology of TBI.

neuroscience↗

bioRxiv2020

Shank2 expression identifies a subpopulation of glycinergic interneurons involved in nociception and altered in an autism mouse model

Patients suffering from Autism Spectrum Disorders (ASD) experience disturbed nociception in form of either hyposensitivity to pain or hypersensitivity and allodynia. We have determined that Shank2-KO mice, which recapitulate the genetic and behavioural disturbances of ASD, display increased sensitivity to formalin pain and thermal, but not mechanical allodynia. We demonstrate that high levels of Shank2 expression identifies a subpopulation of neurons in murine and human dorsal spinal cord, composed mainly by glycinergic interneurons and that loss of Shank2 causes the decrease in NMDAR in excitatory synapses on these inhibitory interneurons. In fact, in the subacute phase of the formalin test, glycinergic interneurons are strongly activated in WT mice but not in Shank2-KO mice. As consequence, nociception projection neurons in lamina I are activated in larger numbers in Shank2-KO mice. Our findings prove that Shank2 expression identifies a new subset of inhibitory interneurons involved in reducing the transmission of nociceptive stimuli and whose unchecked activation is associated with pain hypersensitivity. Thus, we provide evidence that dysfunction of spinal cord pain processing circuits may underlie the nociceptive phenotypes in ASD patients and mouse models.

neuroscience↗