Application of adipose-derived mesenchymal stem cells in an in vivo model of peripheral nerve damage

[EN] Background: Neuropathic pain is one of the most difficult to treat chronic pain syndromes. It has significant effects on patients’ quality of life and substantially adds to the burden of direct and indirect medical costs. There is a critical need to improve therapies for peripheral nerve regeneration. The aim of this study is to address this issue by performing a detailed analysis of the therapeutic benefits of two treatment options: adipose tissue derived-mesenchymal stem cells (ASCs) and ASC-conditioned medium (CM). Methods: To this end, we used an in vivo rat sciatic nerve damage model to investigate the molecular mechanisms involved in the myelinating capacity of ASCs and CM. Furthermore, effect of TNF and CM on Schwann cells (SCs) was evaluated. For our in vivo model, biomaterial surgical implants containing TNF were used to induce peripheral neuropathy in rats. Damaged nerves were also treated with either ASCs or CM and molecular methods were used to collect evidence of nerve regeneration. Post-operatively, rats were subjected to walking track analysis and their sciatic functional index was evaluated. Morphological data was gathered through transmission electron microscopy (TEM) of sciatic nerves harvested from the experimental rats. We also evaluated the effect of TNF on Schwann cells (SCs) in vitro. Genes and their correspondent proteins associated with nerve regeneration were analyzed by qPCR, western blot, and confocal microscopy. Results: Our data suggests that both ASCs and CM are potentially beneficial treatments for promoting myelination and axonal regeneration. After TNF-induced nerve damage we observed an upregulation of c-Jun along with a downregulation of Krox-20 myelin-associated transcription factor. However, when CM was added to TNF-treated nerves the opposite effect occurred and also resulted in increased expression of myelin-related genes and their corresponding proteins. Conclusion: Findings from our in vivo model showed that both ASCs and CM aided the regeneration of axonal myelin sheaths and the remodeling of peripheral nerve morphologySIThis study was supported by the Fundación Leonesa ProNeurociencias. The AW’s Lab was supported by AEI/FEDER, EU (RTI2018-097503-B-I00) and the European Community’s H2020 Framework Program ERC Consolidator Grant (865157- MYERIBO

Gene Regulatory Network in Schwann cell Disorders

222 p.Cancer cells can develop a strong addiction to discrete molecular regulators, which control the aberranttranscription programs that drive and maintain the cancer phenotype. Here, we report the identificationof the RNA-binding protein HuR as a central oncogenic driver for malignant peripheral nerve sheathtumours (MPNSTs), which are highly aggressive sarcomas. We show HuR was bound to a multitude ofcancer-associated transcripts in human MPNST samples. Accordingly, genetic and pharmacologicalinhibition of HuR had potent cytostatic and cytotoxic effects on tumour growth, and strongly supressedmetastatic capacity in vivo. Importantly, we linked the profound tumorigenic function of HuR to itsability to simultaneously regulate multiple essential oncogenic pathways in MPNST cellls, including theWnt/ß-Catenin, YAP/TAZ, Rb-E2F and BET proteins, which converge on key transcriptional networks.Regulating survival, proliferation, and dissemination. Therefore, we propose HuR represents an idealtherapeutic target for MPNST treatment. Peripheral nervous system involvement has also beenobserved in Lyme disease-assicated clinical manifestations, which is the most common arthropod-borne infectious disease in temperate regions. It is caused by infection with the spirochete Borreliaburgdorferi, which is transmitted by a tick bite. Here, we identified Schwann cells as the new targets ofB. burgdorferi, leading to demyelination in the absence of immune cells. We suggest that B. burgdorferiregulates intracellular signaling pathways, including Wnt/ß-Catenin, to strongly repress myelin gene andprotein expression, throwing light on one of the most intriguing pathological features of Lyme disease.CICbioGUN

Gene Regulatory Network in Schwann cell Disorders

222 p.Cancer cells can develop a strong addiction to discrete molecular regulators, which control the aberranttranscription programs that drive and maintain the cancer phenotype. Here, we report the identificationof the RNA-binding protein HuR as a central oncogenic driver for malignant peripheral nerve sheathtumours (MPNSTs), which are highly aggressive sarcomas. We show HuR was bound to a multitude ofcancer-associated transcripts in human MPNST samples. Accordingly, genetic and pharmacologicalinhibition of HuR had potent cytostatic and cytotoxic effects on tumour growth, and strongly supressedmetastatic capacity in vivo. Importantly, we linked the profound tumorigenic function of HuR to itsability to simultaneously regulate multiple essential oncogenic pathways in MPNST cellls, including theWnt/ß-Catenin, YAP/TAZ, Rb-E2F and BET proteins, which converge on key transcriptional networks.Regulating survival, proliferation, and dissemination. Therefore, we propose HuR represents an idealtherapeutic target for MPNST treatment. Peripheral nervous system involvement has also beenobserved in Lyme disease-assicated clinical manifestations, which is the most common arthropod-borne infectious disease in temperate regions. It is caused by infection with the spirochete Borreliaburgdorferi, which is transmitted by a tick bite. Here, we identified Schwann cells as the new targets ofB. burgdorferi, leading to demyelination in the absence of immune cells. We suggest that B. burgdorferiregulates intracellular signaling pathways, including Wnt/ß-Catenin, to strongly repress myelin gene andprotein expression, throwing light on one of the most intriguing pathological features of Lyme disease.CICbioGUN

In vitro study to assess modulation of Candida biofilm by Escherichia coli from vaginal strains

Background: Vulvovaginal candidiasis (VVC) is caused by biofilm formation and epithelial invasion. In addition, Escherichia coli (EC) can establish a vaginal intracellular reservoir modulating Candida spp. biofilm production. We aimed to analyze the behavior of Candida albicans (CA) and EC biofilm both in single cultures and in co-cultures. Methods: We prospectively collected CA and EC isolates from vaginal swabs over 6 months. We selected positive cultures with both CA and EC (cases) and a comparator group with either CA or EC (controls). We analyzed overall biomass production and metabolic activity in single cultures and in co-cultures based on staining assays, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) to assess biofilm occupation. We also analyzed clinical manifestations. Results: We cultured 455 samples, 16 (3.5%) of which had CA and EC (cases); only CA or EC (controls) was detected, respectively, in 72 (15.8%) and 98 (21.5%). Biomass production and metabolic activity were significantly more pronounced in co-cultures in both groups. CLSM and SEM, on the other hand, showed the biofilm of each species to be significantly reduced when they were cultured together, with higher values in CA (percentage biofilm reduction: CA, 95.8% vs. EC, 36.2%, p < 0.001). There were no clinically significant differences between co-infected patients and patients infected only by C. albicans. Conclusion: Ours is the first study assessing co-cultures of CA and EC in a large collection of samples. We observed that coinfection of CA and EC was unusual (3.5%) and promoted high biomass, whereas microscopy enabled us to detect a reduction in biofilm production when microorganisms were co-cultured. No differences in symptoms were observed

Schwann cell autophagy, myelinophagy, initiates myelin clearance from injured nerves

Although Schwann cell myelin breakdown is the universal outcome of a remarkably wide range of conditions that cause disease or injury to peripheral nerves, the cellular and molecular mechanisms that make Schwann cell-mediated myelin digestion possible have not been established. We report that Schwann cells degrade myelin after injury by a novel form of selective autophagy, myelinophagy. Autophagy was up-regulated by myelinating Schwann cells after nerve injury, myelin debris was present in autophagosomes, and pharmacological and genetic inhibition of autophagy impaired myelin clearance. Myelinophagy was positively regulated by the Schwann cell JNK/c-Jun pathway, a central regulator of the Schwann cell reprogramming induced by nerve injury. We also present evidence that myelinophagy is defective in the injured central nervous system. These results reveal an important role for inductive autophagy during Wallerian degeneration, and point to potential mechanistic targets for accelerating myelin clearance and improving demyelinating diseas