A panel of CSF proteins separates genetic frontotemporal dementia from presymptomatic mutation carriers: a GENFI study

Background A detailed understanding of the pathological processes involved in genetic frontotemporal dementia is critical in order to provide the patients with an optimal future treatment. Protein levels in CSF have the potential to reflect different pathophysiological processes in the brain. We aimed to identify and evaluate panels of CSF proteins with potential to separate symptomatic individuals from individuals without clinical symptoms (unaffected), as well as presymptomatic individuals from mutation non-carriers. Methods A multiplexed antibody-based suspension bead array was used to analyse levels of 111 proteins in CSF samples from 221 individuals from families with genetic frontotemporal dementia. The data was explored using LASSO and Random forest. Results When comparing affected individuals with unaffected individuals, 14 proteins were identified as potentially important for the separation. Among these, four were identified as most important, namely neurofilament medium polypeptide (NEFM), neuronal pentraxin 2 (NPTX2), neurosecretory protein VGF (VGF) and aquaporin 4 (AQP4). The combined profile of these four proteins successfully separated the two groups, with higher levels of NEFM and AQP4 and lower levels of NPTX2 in affected compared to unaffected individuals. VGF contributed to the models, but the levels were not significantly lower in affected individuals. Next, when comparing presymptomatic GRN and C9orf72 mutation carriers in proximity to symptom onset with mutation non-carriers, six proteins were identified with a potential to contribute to a separation, including progranulin (GRN). Conclusion In conclusion, we have identified several proteins with the combined potential to separate affected individuals from unaffected individuals, as well as proteins with potential to contribute to the separation between presymptomatic individuals and mutation non-carriers. Further studies are needed to continue the investigation of these proteins and their potential association to the pathophysiological mechanisms in genetic FTD.

Neurogranin and Neuronal Pentraxin Receptor as Synaptic Dysfunction Biomarkers in Alzheimer’s Disease

Synaptic loss and dysfunction are one of the earliest signs of neurodegeneration associated with cognitive decline in Alzheimer’s disease (AD). It seems that by assessing proteins related to synapses, one may reflect their dysfunction and improve the understanding of neurobiological processes in the early stage of the disease. To our best knowledge, this is the first study that analyzes the CSF concentrations of two synaptic proteins together, such as neurogranin (Ng) and neuronal pentraxins receptor (NPTXR) in relation to neurochemical dementia biomarkers in Alzheimer’s disease. Methods: Ng, NPTXR and classical AD biomarkers concentrations were measured in the CSF of patients with AD and non-demented controls (CTRL) using an enzyme-linked immunosorbent assay (ELISA) and Luminex xMAP technology. Results: The CSF level of Ng was significantly higher, whereas the NPTXR was significantly lower in the AD patients than in cognitively healthy controls. As a first, we calculated the NPTXR/Ng ratio as an indicator of synaptic disturbance. The patients with AD presented a significantly decreased NPTXR/Ng ratio. The correlation was observed between both proteins in the AD and the whole study group. Furthermore, the relationship between the Ng level and pTau181 was found in the AD group of patients. Conclusions: The Ng and NPTXR concentrations in CSF are promising synaptic dysfunction biomarkers reflecting pathological changes in AD.

Neuronal exosome proteins: novel biomarkers for predicting neonatal response to therapeutic hypothermia

ObjectiveCentral nervous system (CNS) derived exosomes can be purified from peripheral blood and have been used widely in adult neurological disease. Application to neonatal neurological disease deserves investigation in the setting of hypoxic–ischaemic encephalopathy (HIE).DesignObservational cohort.SettingLevel III neonatal intensive care unit.ParticipantsTerm/near-term neonates undergoing therapeutic hypothermia (TH) for HIE.InterventionsBlood samples were collected at 0–6, 12, 24, 48 and 96 hours of life.Main outcomes and measuresCNS exosomes were purified from serum using previously described methods. Biomarker protein levels were quantified using standard ELISA methods and normalised to exosome marker CD-81. The slope of change for biomarker levels was calculated for each time interval. Our primary outcome was MRI basal ganglia/watershed score of ≥3.Results26 subjects were included (umbilical artery pH range 6.6–7.29; 35% seizures). An increasing MRI injury score was significantly associated with decreasing levels of synaptopodin between 0–6 and 12 hours (p=0.03) and increasing levels of lipocalin-2 (NGAL) between 12 and 48 hours (p<0.0001). Neuronal pentraxin was not significant. The negative predictive values for increasing synaptopodin and decreasing NGAL was 70.0% and 90.9%, respectively.Conclusions and relevanceOur results indicate that CNS exosome cargo has the potential to act as biomarkers of the severity of brain injury and response to TH as well as quantify pharmacological response to neuroactive therapeutic/adjuvant agents. Rigorous prospective trials are critical to evaluate potential clinical use of exosome biomarkers.

Surrogate Cerebrospinal Fluid Biomarkers for Assessing the Efficacy of Gene Therapy in Hurler Syndrome

Mucopolysaccharidosis type I (MPS I) is caused by a deficiency of the lysosomal hydroxylase alpha-l-iduronidase (IDUA). The resulting accumulation of dermatan and heparan sulfate induces intellectual disabilities and pre-mature death, and only a few treatment options are available. In a previous study, we demonstrated the feasibility, safety, and efficacy of gene therapy by injecting recombinant adeno-associated viral vector serotype (AAV)2/5-IDUA into the brain of a canine model of MPS I. We report on a quantitative proteomic analysis of control dogs and untreated dogs with MPS I cerebrospinal fluid (CSF) that had been collected throughout the study in the MPS I dogs. Mass spectrometry (MS) analysis identified numerous proteins present at altered levels in MPS I CSF samples. Quantitative immunoblotting, performed on CSF from healthy controls, untreated MPS I dogs, and MPS I dogs early treated and late treated by gene therapy, confirmed the MS data for a subset of proteins with higher abundance (neuronal pentraxin 1, chitinase 3-like 1, monocyte differentiation antigen CD14, and insulin-like growth factor-binding protein 2). Scoring of the results shows that the expression levels of these proteins are close to those of the control group for dogs that underwent gene therapy early in life but not for older treated animals. Our results disclose four novel predictive biomarker candidates that might be valuable in monitoring the course of the neurological disease in MPS patients at diagnosis, during clinical follow-up, and after treatment.

Overexpression of NPTX2 Promotes Malignant Phenotype of Epithelial Ovarian Carcinoma via IL6-JAK2/STAT3 Signaling Pathway Under Hypoxia

BackgroundEpithelial ovarian cancer (EOC) is the main subtype of ovarian cancer and shows an aggressive phenotype and poor prognosis. Neuronal pentraxin II (NPTX2) is a member of the neuronal pentraxin family and plays a contradictory role in different tumors. However, there has been no report about the possible role and effect of NPTX2 in EOC.MethodsBioinformatics analysis, qPCR, western blotting and immunohistochemistry were used to detect the expression of NPTX2 in EOC. Lentivirus-based transfection for NPTX2 overexpression or knockdown was performed on the EOC cell lines A2780, HEY, SKOV3 and OVCAR-3. The effect of NPTX2 on the malignant phenotype of EOC was examined through methods of MTS assay, Edu assay, transwell assay, western blotting analysis, qPCR analysis, luciferase reporter assay and xenograft experiment.ResultsEOC tissues showed higher NPTX2 expression than the normal tissues with poor prognosis. NPTX2 overexpression can promote the proliferation, invasion, migration and tumorigenesis of EOC via IL6-JAK2/STAT3 signaling pathway. Moreover, hypoxia-inducible factor-1(HIF-1) can promote the transcription and expression of NPTX2 under the hypoxic environment. NPTX2 knockdown abolished the hypoxia-induced malignant phenotypes in ECO.ConclusionsThe above results suggest that NPTX2 may play a novel role in ovarian cancer’s malignant phenotype and act as a promising treatment target for EOC molecular therapy.