Epigenomic Profiling of Human CD4+ T Cells Supports a Linear Differentiation Model and Highlights Molecular Regulators of Memory Development

SummaryThe impact of epigenetics on the differentiation of memory T (Tmem) cells is poorly defined. We generated deep epigenomes comprising genome-wide profiles of DNA methylation, histone modifications, DNA accessibility, and coding and non-coding RNA expression in naive, central-, effector-, and terminally differentiated CD45RA+ CD4+ Tmem cells from blood and CD69+ Tmem cells from bone marrow (BM-Tmem). We observed a progressive and proliferation-associated global loss of DNA methylation in heterochromatic parts of the genome during Tmem cell differentiation. Furthermore, distinct gradually changing signatures in the epigenome and the transcriptome supported a linear model of memory development in circulating T cells, while tissue-resident BM-Tmem branched off with a unique epigenetic profile. Integrative analyses identified candidate master regulators of Tmem cell differentiation, including the transcription factor FOXP1. This study highlights the importance of epigenomic changes for Tmem cell biology and demonstrates the value of epigenetic data for the identification of lineage regulators

Control of interneuron dendritic growth through NRG1/erbB4-mediated kalirin-7 disinhibition.

Neuregulin 1 (NRG1) is a secreted trophic factor that activates the postsynaptic erbB4 receptor tyrosine kinase. Both NRG1 and erbB4 have been repeatedly associated with schizophrenia, but their downstream targets are not well characterized. ErbB4 is highly abundant in interneurons, and NRG1-mediated erbB4 activation has been shown to modulate interneuron function, but the role for NRG1-erbB4 signaling in regulating interneuron dendritic growth is not well understood. Here we show that NRG1/erbB4 promote the growth of dendrites in mature interneurons through kalirin, a major dendritic Rac1-GEF. Recent studies have shown associations of the KALRN gene with schizophrenia. Our data point to an essential role of phosphorylation in kalirin-7's C terminus as the critical site for these effects. As reduced interneuron dendrite length occurs in schizophrenia, understanding how NRG1-erbB4 signaling modulates interneuron dendritic morphogenesis might shed light on disease-related alterations in cortical circuits

Embryonic Stem Cell-Derived L1 Overexpressing Neural Aggregates Enhance Recovery after Spinal Cord Injury in Mice

An obstacle to early stem cell transplantation into the acutely injured spinal cord is poor survival of transplanted cells. Transplantation of embryonic stem cells as substrate adherent embryonic stem cell-derived neural aggregates (SENAs) consisting mainly of neurons and radial glial cells has been shown to enhance survival of grafted cells in the injured mouse brain. In the attempt to promote the beneficial function of these SENAs, murine embryonic stem cells constitutively overexpressing the neural cell adhesion molecule L1 which favors axonal growth and survival of grafted and imperiled cells in the inhibitory environment of the adult mammalian central nervous system were differentiated into SENAs and transplanted into the spinal cord three days after compression lesion. Mice transplanted with L1 overexpressing SENAs showed improved locomotor function when compared to mice injected with wild-type SENAs. L1 overexpressing SENAs showed an increased number of surviving cells, enhanced neuronal differentiation and reduced glial differentiation after transplantation when compared to SENAs not engineered to overexpress L1. Furthermore, L1 overexpressing SENAs rescued imperiled host motoneurons and parvalbumin-positive interneurons and increased numbers of catecholaminergic nerve fibers distal to the lesion. In addition to encouraging the use of embryonic stem cells for early therapy after spinal cord injury L1 overexpression in the microenvironment of the lesioned spinal cord is a novel finding in its functions that would make it more attractive for pre-clinical studies in spinal cord regeneration and most likely other diseases of the nervous system

Water Extract from the Leaves of Withania somnifera Protect RA Differentiated C6 and IMR-32 Cells against Glutamate-Induced Excitotoxicity

Glutamate neurotoxicity has been implicated in stroke, head trauma, multiple sclerosis and neurodegenerative disorders. Search for herbal remedies that may possibly act as therapeutic agents is an active area of research to combat these diseases. The present study was designed to investigate the neuroprotective role of Withania somnifera (Ashwagandha), also known as Indian ginseng, against glutamate induced toxicity in the retinoic acid differentiated rat glioma (C6) and human neuroblastoma (IMR-32) cells. The neuroprotective activity of the Ashwagandha leaves derived water extract (ASH-WEX) was evaluated. Cell viability and the expression of glial and neuronal cell differentiation markers was examined in glutamate challenged differentiated cells with and without the presence of ASH-WEX. We demonstrate that RA-differentiated C6 and IMR-32 cells, when exposed to glutamate, undergo loss of neural network and cell death that was accompanied by increase in the stress protein HSP70. ASH-WEX pre-treatment inhibited glutamate-induced cell death and was able to revert glutamate-induced changes in HSP70 to a large extent. Furthermore, the analysis on the neuronal plasticity marker NCAM (Neural cell adhesion molecule) and its polysialylated form, PSA-NCAM revealed that ASH-WEX has therapeutic potential for prevention of neurodegeneration associated with glutamate-induced excitotoxicty

Identification and Validation of Novel Cerebrospinal Fluid Biomarkers for Staging Early Alzheimer's Disease

Ideally, disease modifying therapies for Alzheimer disease (AD) will be applied during the 'preclinical' stage (pathology present with cognition intact) before severe neuronal damage occurs, or upon recognizing very mild cognitive impairment. Developing and judiciously administering such therapies will require biomarker panels to identify early AD pathology, classify disease stage, monitor pathological progression, and predict cognitive decline. To discover such biomarkers, we measured AD-associated changes in the cerebrospinal fluid (CSF) proteome.CSF samples from individuals with mild AD (Clinical Dementia Rating [CDR] 1) (n = 24) and cognitively normal controls (CDR 0) (n = 24) were subjected to two-dimensional difference-in-gel electrophoresis. Within 119 differentially-abundant gel features, mass spectrometry (LC-MS/MS) identified 47 proteins. For validation, eleven proteins were re-evaluated by enzyme-linked immunosorbent assays (ELISA). Six of these assays (NrCAM, YKL-40, chromogranin A, carnosinase I, transthyretin, cystatin C) distinguished CDR 1 and CDR 0 groups and were subsequently applied (with tau, p-tau181 and Aβ42 ELISAs) to a larger independent cohort (n = 292) that included individuals with very mild dementia (CDR 0.5). Receiver-operating characteristic curve analyses using stepwise logistic regression yielded optimal biomarker combinations to distinguish CDR 0 from CDR>0 (tau, YKL-40, NrCAM) and CDR 1 from CDR<1 (tau, chromogranin A, carnosinase I) with areas under the curve of 0.90 (0.85-0.94 95% confidence interval [CI]) and 0.88 (0.81-0.94 CI), respectively.Four novel CSF biomarkers for AD (NrCAM, YKL-40, chromogranin A, carnosinase I) can improve the diagnostic accuracy of Aβ42 and tau. Together, these six markers describe six clinicopathological stages from cognitive normalcy to mild dementia, including stages defined by increased risk of cognitive decline. Such a panel might improve clinical trial efficiency by guiding subject enrollment and monitoring disease progression. Further studies will be required to validate this panel and evaluate its potential for distinguishing AD from other dementing conditions

Toxicology and safety of the tincture of Operculina alata in patients with functional constipation

The tincture of Operculina alata, popularly known as "tincture of jalapa", is used in Northeast Brazil to treat constipation and encephalic vascular accident, but it has not yet been adequately tested for safety and efficacy. The aim of this study was to evaluate the toxicology and safety of the tincture of O. alata in patients with functional constipation. This was a double-blind, randomized, placebo-controlled clinical trial. The study consisted of three phases: pre-treatment, treatment and post-treatment, each phase with duration of seven days. Arterial pressure, heart rate, body weight, adverse events, hematological, metabolic, liver and kidney functions were monitored. Forty patients were randomized to receive tincture of O. alata and 43 patients to receive placebo. There were statistical differences in the clinical aspects between groups, but these changes were not considered clinically significant. Adverse events were considered not serious and of mild intensity, especially dizziness, headache, abdominal pain and nausea. This clinical trial confirmed the safety of the tincture of O. alata in the pharmaceutical form and dosage tested, allowing the product to be safely used in a larger population for the assessment of its clinical efficacy.A tintura de Operculina alata, popularmente conhecida como "tintura de jalapa", é usada no Nordeste do Brasil para tratar constipação intestinal e acidente vascular encefálico, mas sua eficácia e segurança ainda não foram confirmadas. O objetivo deste estudo foi avaliar a toxicologia e segurança da tintura de O. alata em pacientes com constipação intestinal funcional. Este foi um ensaio clínico duplo-cego, randomizado e controlado por placebo. O estudo consistiu de três fases: pré-tratamento, tratamento e pós-tratamento, cada fase com duração de sete dias. Foram monitorizados a pressão arterial, frequência cardíaca, peso corporal, eventos adversos e funções hematológica, metabólica, hepática e renal. Quarenta pacientes foram randomizados para receber tintura de O. alata e 43 pacientes para receber placebo. Houve diferenças estatísticas nos aspectos clínicos entre os grupos, contudo, estas mudanças não foram consideradas clinicamente significativas. Eventos adversos foram considerados não sérios e de leve intensidade, especialmente, cefaléia, tontura, dor abdominal e náusea. Este ensaio clínico confirmou a segurança da tintura de O. alata na forma farmacêutica e dosagem testada, permitindo que o produto seja testado em população maior para determinar sua eficácia clínica