An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Traumatic brain injury (TBI) is a serious global health problem, many individuals live with TBI-related neurological dysfunction. A lack of biomarkers of TBI has impeded medication development. To identify new potential biomarkers, we time-dependently evaluated mouse brain tissue and neuronally derived plasma extracellular vesicle proteins in a mild model of TBI with parallels to concussive head injury. Mice (CD-1, 30–40 g) received a sham procedure or 30 g weight-drop and were euthanized 8, 24, 48, 72, 96 hr, 7, 14 and 30 days later. We quantified ipsilateral cortical proteins, many of which differed from sham by 8 hours post-mTBI, particularly GAS-1 and VEGF-B were increased while CXCL16 reduced, 23 proteins changed in 4 or more of the time points. Gene ontology pathways mapped from altered proteins over time related to pathological and physiological processes. Validation of proteins identified in this study may provide utility as treatment response biomarkers.

IMPORTANCE Exenatide, a glucagon-like peptide 1 agonist used in type 2 diabetes, was recently found to have beneficial effects on motor function in a randomized, placebo-controlled trial in Parkinson disease (PD). Accumulating evidence suggests that impaired brain insulin and protein kinase B (Akt) signaling play a role in PD pathogenesis; however, exploring the extent to which drugs engage with putative mechnisms in vivo remains a challenge. OBJECTIVE To assess whether participants in the Exenatide-PD trial have augmented activity in brain insulin and Akt signaling pathways. DESIGN, SETTING, AND PARTICIPANTS Serum samples were collected from 60 participants in the single-center Exenatide-PD trial (June 18,2014, to June 16,2016), which compared patients with moderate PD randomized to 2 mg of exenatide once weekly or placebo for 48 weeks followed by a 12-week washout period. Serum extracellular vesicles, including exosomes, were extracted, precipitated, and enriched for neuronal source by anti-L1cell adhesion molecule antibody absorption, and proteins of interest were evaluated using electrochemiluminescence assays. Statistical analysis was performed from May 1,2017, to August 31,2017. MAIN OUTCOMES AND MEASURES The main outcome was augmented brain insulin signaling that manifested as a change in tyrosine phosphorylated insulin receptor substrate 1 within neuronal extracellular vesicles at the end of 48 weeks of exenatide treatment. Additional outcome measures were changes in other insulin receptor substrate proteins and effects on protein expression in the Akt and mitogen-activated protein kinase pathways. RESULTS Sixty patients (mean [SD] age, 59.9 [8.4] years; 43 [72%] male) participated in the study: 31 in the exenatide group and 29 in the placebo group (data from 1 patient in the exenatide group were excluded). Patients treated with exenatide had augmented tyrosine phosphorylation of insulin receptor substrate tat 48 weeks (0.27 absorbance units [AU]; 95% CI, 0.09-0.44 AU; P = .003) and 60 weeks (0.23 AU; 95% CI, 0.05-0.41AU; P = .01) compared with patients receiving placebo. Exenatide-treated patients had elevated expression of downstream substrates, including total Akt (0.35 U/mL; 95% CI, 0.16-0.53 U/mL; P < .001) and phosphorylated mechanistic target of rapamycin (mTOR) (0.22 AU; 95% CI, 0.04-0.40 AU; P = .02). Improvements in Movement Disorders Society Unified Parkinson's Disease Rating Scale part 3 off-medication scores were associated with levels of total mTOR (F-4.50 = 5.343, P = .001) and phosphorylated mTOR (F-4.50 = 4.384, P = .04). CONCLUSIONS AND RELEVANCE The results of this study are consistent with target engagement of brain insulin, Akt, and mTOR signaling pathways by exenatide and provide a mechanistic context for the clinical findings of the Exenatide-PD trial. This study suggests the potential of using exosome-based biomarkers as objective measures of target engagement in clinical trials using drugs that target neuronal pathways.

Traumatic brain injury (TBI) is a major cause of injury-related death throughout the world and lacks effective treatment. Surviving TBI patients often develop neuropsychiatric symptoms, and the molecular mechanisms underlying the neuronal damage and recovery following TBI are not well understood. Extracellular vesicles (EVs) are membranous nanoparticles that are divided into exosomes (originating in the endosomal/multi-vesicular body [MVB] system) and microvesicles (larger EVs produced through budding of the plasma membrane). Both types of EVs are generated by all cells and are secreted into the extracellular environment, and participate in cell-to-cell communication and protein and RNA delivery. EVs enriched for neuronal origin can be harvested from peripheral blood samples and their contents quantitatively examined as a window to follow potential changes occurring in brain. Recent studies suggest that the levels of exosomal proteins and microRNAs (miRNAs) may represent novel biomarkers to support the clinical diagnosis and potential response to treatment for neurological disorders. In this review, we focus on the biogenesis of EVs, their molecular composition, and recent advances in research of their contents as potential diagnostic tools for TBI.

April 25, 2018April 10, 2018Free AccessExenatide Modulates Neuronal Insulin Signalling in Parkinson’s Disease (S27.002)Dilan Athauda, Seema Gulyani, Hanuma Karnati, Yazhou Li, David Tweedie, Simon Skene, Kashfia Chowdhury, Nigel Greig, Dimitrios Kapogiannis, and Thomas FoltynieAuthors Info & AffiliationsApril 10, 2018 issue90 (15_supplement)https://doi.org/10.1212/WNL.90.15_supplement.S27.002 Letters to the Editor

Adipokines are bioactive proteins that mediate proliferation, metabolism, inflammation, and angiogenesis. Adiponectin is an important adipokine that exerts multiple key functions via its anti-metabolic syndrome and anti-inflammatory properties. A number of adiponectin receptors, AdipoR1, AdipoR2 and T-cadherin, have been identified. Recent studies have suggested the involvement of adiponectin and receptors in several cancers, including prostate, breast, endometrial, brain, and colon cancer. Altered levels of adiponectin expression, or its interacting receptors, in cancers can lead to dysregulation of signaling pathways. Our current review describes the molecular mechanisms underlying the anti-tumorigenesis activity of adiponectin and the role of its receptors in prostate carcinogenesis, and provides perspectives of adiponectin-mediated signaling as a potential target for therapy.

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity worldwide. Neuroinflammation is prominent in the short and long-term consequences of neuronal injuries that occur after TBI. Neuroinflammation involves the activation of glia, including microglia and astrocytes, to release inflammatory mediators within the brain, and the subsequent recruitment of peripheral immune cells. Various animal models of TBI have been developed that have proved valuable to elucidate the pathophysiology of the disorder and to assess the safety and efficacy of novel therapies prior to clinical trials. These models provide an excellent platform to delineate key injury mechanisms that associate with types of injury (concussion, contusion, and penetration injuries) that occur clinically for the investigation of mild, moderate, and severe forms of TBI. Additionally, TBI modeling in genetically engineered mice, in particular, has aided the identification of key molecules and pathways for putative injury mechanisms, as targets for development of novel therapies for human TBI. This Review details the evidence showing that neuroinflammation, characterized by the activation of microglia and astrocytes and elevated production of inflammatory mediators, is a critical process occurring in various TBI animal models, provides a broad overview of commonly used animal models of TBI, and overviews representative techniques to quantify markers of the brain inflammatory process. A better understanding of neuroinflammation could open therapeutic avenues for abrogation of secondary cell death and behavioral symptoms that may mediate the progression of TBI.

Toll-like receptors (TLRs) that sense the microbial pathogens are important components of host immune system. TLRs play key roles in the innate defence mechanism against pathogens, in the development of adaptive immunity, and are possibly the major determinants of the susceptibility to infections. To study the resistance pattern in different breeds of chicken, a comprehensive understanding of TLR4 signalling pathways is required. We investigated the TLR-4 pathway regulated gene expressions in PBMCs of chicken breeds of Broiler (Cobb), Aseel, Dahlem Red and Ghagus upon LPS treatment using Quantitative RT-PCR approach. Several genes were found to be up regulated in both TLR-induced MyD88-dependent and MyD88-independent pathways. These genes include TLR4 (Toll-like receptor 4), MyD88 (Myeloid differentiation primary response gene 88), TRAF6 (TNF receptor associated factor 6), TRIF (TIR domain containing adapter inducing interferon beta), the transcription factors NFkB (Nuclear factor kappa B), IRF7 (Interferon regulatory factor 7) and IFN β (Interferon beta). We have also studied inflammatory cytokines such as IL2, IL6, IL8, IL1 β and TNF α to further understand the downstream signalling of TLR4 pathway. These results showed that higher expression of TLR signalling activation via both MyD88-dependent and TRIF-dependent pathways are more beneficial to chicken mononuclear cells mediated innate immunity. We observed TRIF dependent pathway in Aseel and Ghagus breeds. Our results are in concurrent with general observation that Aseel breed is comparatively more resistant, Ghagus and broilers are moderately resistant and Dahlem Red is comparatively more susceptible to bacterial infections.

microRNAs (miRNAs) are small length noncoding RNAs which play a key role in cellular processes such as proliferation, differentiation, and development of lineage hematopoietic cells and matured blood cells. Aberrant expression of miRNAs has been reported in several hematopoietic disorders. The involvement of miRNAs in regulation of various signaling pathways has been shown in hematopoietic disorders. Along with regulatory role, miRNAs are also proven as diagnostic and prognostic markers for these malignancies. Recent studies are evidenced that the miRNA are key regulators of hematopoietic disorders and progression of these disorders shows the importance of targeting the aberrant expression of miRNAs as new therapeutic interventions. The present chapter provides overview of the art related to the importance of miRNAs in developmental hematopoiesis and pathogenesis of hematopoietic disorders including chronic lymphocytic leukemia, chronic myelogenous leukemia, multiple myelomas, and B cell lymphomas.

MicroRNAs (miRNAs) are endogenous, ∼22 nucleotide, non-coding RNA molecules that function as post-transcriptional regulators of gene expression. miRNA dysregulation has been observed in cancer and in neurodegenerative disorders such as Alzheimer's, Parkinson's, and Huntington's diseases, amyotrophic lateral sclerosis, and the neurological disorder, epilepsy. Neuronal degradation and death are important hallmarks of neurodegenerative disorders. Additionally, abnormalities in metabolism, synapsis and axonal transport have been associated with Alzheimer's disease, Parkinson's disease, and frontotemporal dementia. A number of recently published studies have demonstrated the importance of miRNAs in the nervous system and have contributed to the growing body of evidence on miRNA dysregulation in neurological disorders. Knowledge of the expressions and activities of such miRNAs may aid in the development of novel therapeutics. In this review, we discuss the significance of miRNA dysregulation in the development of neurodegenerative disorders and the use of miRNAs as targets for therapeutic intervention.

Cancer is characterized by uncontrolled cell growth, invasion, and metastasis and possess threat to humans worldwide. The scientific community is facing numerous challenges despite several efforts to cure cancer. Though a number of studies were done earlier, the molecular mechanism of cancer progression is not completely understood. Currently available treatments like surgery resection, adjuvant chemotherapy, and radiotherapy are not completely effective in curing all the cancers. Recent advances in the antisense technology provide a powerful tool to investigate various cancer pathways and target them. Small interfering RNAs (siRNAs) could be effective in downregulating the cancer-associated genes, but their in vivo delivery is the main obstacle. DNA enzymes (DNAzymes) have great potential in the treatment of cancer due to high selectivity and significant catalytic efficiency. In this review, we are focusing on antisense molecules such as siRNA and DNAzymes in cancer therapeutics development. This review also describes the challenges and approaches to overcome obstacles involved in using siRNA and DNAzymes in the treatment of cancers.

Glioblastoma multiforme is the most common form of intracranial malignancy in humans, and is characterized by aggressive tumor growth, tissue invasion and neurodegenerative properties. The present study investigated the expression status of tight junction associated Claudin 1 (CLDN1), Claudin 5 (CLDN5) and Adheren junction associated β-catenin genes in the light of their critical role in the progression of both low- and high-grade human gliomas. Using quantitative PCR and Western blot methods the mRNA and protein status of CLDN1, CLDN5 and β-catenin genes were studied in a total of 25 human gliomas of World Health Organization (WHO) grades I-IV, non-cancerous control brain tissues and their corresponding model cell lines (C6, U373, U118, T98 and U87MG). Quantitative analysis of the transcript and protein expression data showed that CLDN1 and CLDN5 were significantly down regulated (p=<0.001) in tumors of all four grades and model cell lines. This decrease in expression pattern was in accordance with the increasing grade of the tumor. A 4-fold stronger reduction of CLDN1 when compared to CLDN5 was evident in high-grade tumors. Interestingly, β-catenin was up regulated in all tumor types we studied (p=<0.005). Our findings, suggest that down regulated CLDN1 and CLDN5 genes have potential relevance in relation to the progression of glioblastoma multiforme. Hence, their therapeutic targeting may provide both insight and leads to control the cellular proliferation and subsequent invasiveness among affected individuals.