The involvement of the extracellular matrix (ECM) in lesion evolution and functional outcome is well recognized in spinal cord injury. Most attention has been dedicated to the “core” area of the lesion and scar formation, while only scattered reports consider ECM modification based on the temporal evolution and the segments adjacent to the lesion. In this study, we investigated the expression profile of 100 genes encoding for ECM proteins at 1, 8 and 45 days post-injury, in the spinal cord segments rostral and caudal to the lesion and in the scar segment, in a rat model. During both the active lesion phases and the lesion stabilization, we observed an asymmetric gene expression induced by the injury, with a higher regulation in the rostral segment of genes involved in ECM remodeling, adhesion and cell migration. Using bioinformatic approaches, the metalloproteases inhibitor Timp1 and the hyaluronan receptor Cd44 emerged as the hub genes at all post-lesion times. Results from the bioinformatic gene expression analysis were then confirmed at protein level by tissue analysis and by cell culture using primary astrocytes. These results indicated that ECM regulation also takes place outside of the lesion area in spinal cord injury.

Spinal cord injury (SCI) is characterized by a cascade of events that lead to sensory and motor disabilities. To date, this condition is irreversible, and no cure exists. To improve myelin repair and limit secondary degeneration, we developed a multitherapy based on nanomedicines (NMeds) loaded with the promyelinating agent triiodothyronine (T3), used in combination with systemic ibuprofen and mouse nerve growth factor (mNGF). Poly-L-lactic-co-glycolic acid (PLGA) NMeds were optimized and loaded with T3 to promote sustained release. In vitro experiments confirmed the efficacy of T3-NMeds to differentiate oligodendrocyte precursor cells. In vivo rat experiments were performed in contusion SCI to explore the NMed biodistribution and efficacy of combo drugs at short- and long-term post-lesion. A strong anti-inflammatory effect was observed in the short term with a reduction of type M1 microglia and glutamate levels, but with a subsequent increase of TREM2. In the long term, an improvement of myelination in NG2-IR, an increase in MBP content, and a reduction of the demyelination area were observed. These data demonstrated that NMeds can successfully be used to obtain more controlled local drug delivery and that this multiple treatment could be effective in improving the outcome of SCIs.

Cellular and subcellular spatial colocalization of structures and molecules in biological specimens is an important indicator of their co-compartmentalization and interaction. Presently, colocalization in biomedical images is addressed with visual inspection and quantified by co-occurrence and correlation coefficients. However, such measures alone cannot capture the complexity of the interactions, which does not limit itself to signal intensity. On top of the previously developed density distribution maps (DDMs), here, we present a method for advancing current colocalization analysis by introducing co-density distribution maps (cDDMs), which, uniquely, provide information about molecules absolute and relative position and local abundance. We exemplify the benefits of our method by developing cDDMs-integrated pipelines for the analysis of molecules pairs co-distribution in three different real-case image datasets. First, cDDMs are shown to be indicators of colocalization and degree, able to increase the reliability of correlation coefficients currently used to detect the presence of colocalization. In addition, they provide a simultaneously visual and quantitative support, which opens for new investigation paths and biomedical considerations. Finally, thanks to the coDDMaker software we developed, cDDMs become an enabling tool for the quasi real time monitoring of experiments and a potential improvement for a large number of biomedical studies.