Suchergebnisse

Neuronal death can be preceded by progressive dysfunction of axons. Several pathological conditions such as ischemia can disrupt the neuronal cytoskeleton. Microtubules are basic structural components of the neuronal cytoskeleton that regulate axonal transport and neuronal function. Up-to-date, high-resolution observation of microtubules in living neuronal cells is usually accomplished using fluorescent-based microscopy techniques. However, this needs exogenous fluorescence markers to produce the required contrast. This is an invasive procedure that may interfere with the microtubule dynamics. In this work, we show, for the first time to our knowledge, that by using the endogenous (label-free) contrast provided by second harmonic generation (SHG) microscopy, it is possible to identify early molecular changes occurring in the microtubules of living neurons under ischemic conditions. This is done by measuring the intensity modulation of the SHG signal as a function of the angular rotation of the incident linearly polarized excitation light (technique referred to as PSHG). Our experiments were performed in microtubules from healthy control cultured cortical neurons and were compared to those upon application of several periods of oxygen and glucose deprivation (up to 120 min) causing ischemia. After 120-min oxygen and glucose deprivation, a change in the SHG response to the polarization was measured. Then, by using a three-dimensional PSHG biophysical model, we correlated this finding with the structural changes occurring in the microtubules under oxygen and glucose deprivation. To our knowledge, this is the first study performed in living neuronal cells that is based on direct imaging of axons and that provides the means of identifying the early symptoms of ischemia. Live observation of this process might bring new insights into understanding the dynamics and the mechanisms underlying neuronal degeneration or mechanisms of protection or regeneration. ; This work is supported by the Spanish government through the Ministry of Economy and Competitiveness, grants No. TEC2009-09698 and No. FIS2009-09928; the Ministerio de Sanidad, grant No. FIS PI081932; the Laserlab-Europe Cont. grant No. JRA4:Optobio 212025; and the Photonics for Life Networks of Excellence. This research has also been partially supported by Fundació Cellex Barcelona and partially conducted at the Institute of Photonic Sciences' Super-Resolution Light Nanoscopy Facility. ; Peer reviewed

In this paper we provide, for the first time to our knowledge, the effective orientation of the SHG source in cultured cortical neuronal processes in vitro. This is done by the use of the polarization sensitive second harmonic generation (PSHG) imaging microscopy technique. By performing a pixel-level resolution analysis we found that the SHG dipole source has a distribution of angles centered at θe =33.96°, with a bandwidth of ∆θe = 12.85°. This orientation can be related with the molecular geometry of the tubulin heterodimmer contained in microtubules. ; This work is supported by the Generalitat de Catalunya and by the Spanish government grant TEC2006-12654. Authors also acknowledge The Centre for Innovacio i Desenvolupament Empresarial - CIDEM (RDITSCON07-1-0006), Grupo Ferrer and the European Regional Development Fund. This research has been partially supported by Fundació Cellex Barcelona. ; Peer reviewed

Here we used a systems biology approach and artificial intelligence to identify a neuroprotective agent for the treatment of peripheral nerve root avulsion. Based on accumulated knowledge of the neurodegenerative and neuroprotective processes that occur in motoneurons after root avulsion, we built up protein networks and converted them into mathematical models. Unbiased proteomic data from our preclinical models were used for machine learning algorithms and for restrictions to be imposed on mathematical solutions. Solutions allowed us to identify combinations of repurposed drugs as potential neuroprotective agents and we validated them in our preclinical models. The best one, NeuroHeal, neuroprotected motoneurons, exerted anti-inflammatory properties and promoted functional locomotor recovery. NeuroHeal endorsed the activation of Sirtuin 1, which was essential for its neuroprotective effect. These results support the value of network-centric approaches for drug discovery and demonstrate the efficacy of NeuroHeal as adjuvant treatment with surgical repair for nervous system trauma. ; This work was mainly supported by a grant from Fundació La Marató-TV3 (#110432, CC, AB & VP) that funded the work and contracts of TLR and MHG and partially by the Ministerio de Economía y Competitividad of Spain (#SAF 2014-59701, CC, DRG, & TLR). We are also grateful for support from CIBERNED and funding from the European Union Seventh Framework Programme for research, technological development, and demonstration (#306240, XN, FRP & CC). Part of the research leading to these results has also received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 306240. ; Peer reviewed