Biology subjects

Garcia-Verdugo, J. M.

Publications and source records attributed to Garcia-Verdugo, J. M..

3 recordsLinked to original sources

bioRxiv2021

Small Extracellular Vesicles Secreted by Region-specific Astrocytes Ameliorate the Mitochondrial Function in a Cellular Model of Parkinson's Disease

Extracellular vesicles (EVs) are emerging as powerful players in cell-to-cell communication both in health and diseased brain. In Parkinsons disease (PD) - characterized by selective dopaminergic (DAergic) neuron death in ventral midbrain (VMB) and degeneration of DAergic terminals in striatum (STR) - astrocytes (AS) exert dual harmful/protective functions. When activated by chemokine CCL3, AS promote a robust DAergic neuroprotection both in cellular and pre-clinical models of PD, with mechanisms not fully elucidated. Here we used a combination of techniques to characterize AS-EVs derived from VMB and STR, and investigated their potential to exert neuroprotection. First, we show that: (i) AS of both regions secrete small EVs of ~100 nm; (ii) VMB-AS release more EVs per cell than STR-AS under basal conditions; and (iii) only VMB-AS respond to CCL3 by producing more EVs, suggesting differential AS-EV secretion rate according to PD brain region. Next, addressing AS-EV potential against oxidative stress and mitochondrial toxicity, we found that AS-EVs, especially CCL3-AS-EVs, fully counteract H2O2-induced caspase-3 activation. Furthermore, using high resolution respirometry, we demonstrated that AS-EVs rescue the neuronal mitochondrial complex I function impaired by MPP+, with VMB-AS-EVs fully restoring ATP production in MPP+-injured neurons, highlighting a regional diversity of AS-EVs with neuroprotective implications for PD.

neuroscience↗

bioRxiv2021

A ciliopathy complex builds distal appendages to initiate ciliogenesis

Cells inherit two centrioles, the older of which is uniquely capable of generating a cilium. Using proteomics and super-resolved imaging, we identified a module which we term DISCO (DIStal centriole COmplex). DISCO components CEP90, MNR and OFD1 underlie human ciliopathies. This complex localized to both distal centrioles and centriolar satellites, proteinaceous granules surrounding centrioles. Cells and mice lacking CEP90 or MNR did not generate cilia, failed to assemble distal appendages, and did not transduce Hedgehog signals. Disrupting the satellite pools did not affect distal appendage assembly, indicating that it is the centriolar populations of MNR and CEP90 that are critical for ciliogenesis. CEP90 recruited the most proximal known distal appendage component, CEP83, to root distal appendages formation, an early step in ciliogenesis. In addition, MNR, but not CEP90, restricted centriolar length by recruiting OFD1. We conclude that DISCO acts at the distal centriole to support ciliogenesis by restraining centriole length and assembling distal appendages, defects in which cause human ciliopathies. eTOC summaryKumar et al. identifies a multi-protein complex called DISCO (DIStal centriole COmplex) required to nucleate distal appendages and restrain centriole elongation, essential for the initiation of cilium assembly. Without DISCO, cells fail to ciliate and transduce Hedgehog signals, critical for mammalian development.

cell biology↗

bioRxiv2020

Enhanced tissue penetration of antibodies through pressurized immunohistochemistry

To address the inefficiency of passive diffusion for antibody penetration in thick tissue samples, which limits clearing-technique applications, we developed a versatile and simple device to perform antibody incubation under increased barometric pressure. Pressurized immunohistochemistry greatly improves the uniformity, intensity, and depth of fluorescent immunostaining in thick human and mouse brain samples. Furthermore, pressurized immunohistochemistry substantially decreases the time required for classic staining of thin sections. SUBMISSION CATEGORYNew Results

molecular biology↗