Co-Transplantation of Adipose Tissue-Derived Stromal Cells and Olfactory Ensheathing Cells for Spinal Cord Injury Repair

Patients suffering from spinal cord injury (SCI) still have a dismal prognosis. Despite all the efforts developed in this area, currently there are no effective treatments. Therefore, cell therapies have been proposed as a viable alternative to the current treatments used. Adipose tissue-derived stromal cells (ASCs) and olfactory ensheathing cells (OECs) have been used with promising results in different models of SCI, namely due to the regenerative properties of the secretome of the first, and the guidance capability of the second. Using an in vitro model of axonal growth, the dorsal root ganglia explants, we demonstrated that OECs induce neurite outgrowth mainly through cell-cell interactions, while ASCs' effects are strongly mediated by the release of paracrine factors. A proteomic analysis of ASCs' secretome revealed the presence of proteins involved in VEGF, PI3K, and Cadherin signaling pathways, which may be responsible for the effects observed. Then, the cotransplantation of ASCs and OECs showed to improve motor deficits of SCI-rats. Particular parameters of movement such as stepping, coordination, and toe clearance were improved in rats that received the transplant of cells, in comparison to nontreated rats. A histological analysis of the spinal cord tissues revealed that transplantation of ASCs and OECs had a major effect on the reduction of inflammatory cells close the lesion site. A slight reduction of astrogliosis was also evident. Overall, the results obtained with the present work indicate that the cotransplantation of ASCs and OECs brings important functional benefits to the injured spinal cord. Stem Cells 2018;36:696-708.This article is a result of the project (NORTE-01-0145-FEDER-000013), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); Cofinanciado pelo Programa Operacional Regional do Norte (ON.2 SR&TD Integrated Program – NORTE-07-0124-FEDER- 000021), ao abrigo do Quadro de Referência Estrategico Nacional (QREN), através do Fundo Europeu de Desenvolvimento Regional (FEDER); Projeto Estrategico – LA 26 – 2011–2012 and Projeto Estratégico – LA 26 – 2013-2014 cofinan- ciado por fundos nacionais, através da Fundação para a Ciência e a Tecnologia (PEst-C/SAU/LA0026/2011; PEst-C/SAU/LA0026/2013), e pelo Fundo Europeu de DesenvolvimentoRegional (FEDER), através do COMPETE (FCOMP-01-0124- FEDER-022724; FCOMP-01-0124-FEDER-037298 ). Support also from PTDC/NEU-SCC/7051/2014; POCI-01-0145-FEDER-007440; PTDC/NEU-NMC/0205/2012; UID/NEU/04539/2013; The National Mass Spectrometry Network (RNEM) (REDE/1506/ REM/2005). This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the pro- ject POCI-01-0145-FEDER-0070info:eu-repo/semantics/publishedVersio

Neuropilin-2 mediates VEGF-C–induced lymphatic sprouting together with VEGFR3

If neuropilin-2 and the growth factor VEGF-C don’t come together, lymphatic vessels don’t branch apart

Characterisation of the interaction of neuropilin-1 with heparin and a heparan sulfate mimetic library of heparin-derived sugars

Background. Neuropilin-1 (NRP-1) is a multidomain membrane protein with soluble isoforms interacting with a complex network of other membrane receptors, their respective ligands and heparan sulfate (HS). It is involved in the development of vasculature, neural patterning, immunological responses and pathological angiogenesis.Methods. We have characterised the binding of a Fc fusion of rat NRP-1 (Fc rNRP-1) and of a soluble isoform, corresponding to the first four extracellular domains of human NRP-1, shNRP-1, using optical biosensor-based binding assays with a library of heparin derivatives. Selective labelling of lysines protected upon heparin binding allowed their identification by mass spectrometry.Results. Fc rNRP-1 bound to heparin with high affinity (2.5 nM) and fast ka (9.8 × 106 M−1s−1). Unusually, NRP-1 bound both highly sulfated and completely desulfated stretches of heparin and exhibited a complex pattern of preferences for chemically modified heparins possessing one or two sulfate groups, e.g., it bound heparin with just a 6-O sulfate group better than heparin with any two of N-sulfate, 6-O sulfate and 2-O sulfate. Mass-spectrometry based mapping identified that, in addition to the expected the b1 domain, the a1, and c domains and the L2 linker were also involved in the interaction. In contrast, shNRP-1 bound heparin far more weakly. This could only be shown by affinity chromatography and by differential scanning fluorimetry.Discussion. The results suggest that the interaction of NRP-1 with HS is more complex than anticipated and involving a far greater extent of the protein than just the b1–b2 domains. NRP-1’s preference for binding long saccharide structures suggests it has the potential to bind large segments of HS chains and so organise their local structure. In contrast, the four domain soluble isoform, shNRP-1 binds heparin weakly and so would be expected to diffuse away rapidly from the source cell

Differential Scanning Fluorimetry Measurement of Protein Stability Changes upon Binding to Glycosaminoglycans: A Screening Test for Binding Specificity

The interaction between glycosaminoglycans (GAGs) and proteins is important for the regulation of protein transport and activity. Here we present a novel method for the measurement of protein−GAG interactions suitable for high-throughput screening, able to discriminate between the interactions of a protein with GAGs of different structures. Binding of proteins to the GAG heparin, a proxy for sulfated regions of extracellular heparan sulfate, was found to enhance the stability of three test proteins, fibroblast growth factors (FGFs)-1, -2, and -18. Chemically modified heparins and heparin oligosaccharides of different lengths stabilized the three FGFs to different extents, depending on the pattern of sugar binding specificity. The method is based on a differential scanning fluorescence approach. It uses a Sypro Orange dye, which binds to exposed core residues of a denatured protein and results in an increased fluorescence signal. It is convenient, requiring low micromolar amounts of protein and ligand compared to other interaction assays, employing only a real-time polymerase chain reaction (PCR) instrument