title: Dysregulated brain immunity and neurotrophin signaling in Rett syndrome and autism spectrum disorders.
abstract: Rett syndrome is a neurodevelopmental disorder, which occurs in about 1:15,000 females and presents with neurologic and communication defects. It is transmitted as an X-linked dominant linked to mutations of the methyl-CpG-binding protein (MeCP2), a gene transcription suppressor, but its definitive pathogenesis is unknown thus hindering development of effective treatments. Almost half of children with Rett syndrome also have behavioral symptoms consistent with those of autism spectrum disorders (ASDs). PubMed was searched (2005-2014) using the terms: allergy, atopy, brain, brain-derived neurotrophic factor (BDNF), corticotropin-releasing hormone (CRH), cytokines, gene mutations, inflammation, mast cells (MCs), microglia, mitochondria, neurotensin (NT), neurotrophins, seizures, stress, and treatment. There are a number of intriguing differences and similarities between Rett syndrome and ASDs. Rett syndrome occurs in females, while ASDs more often in males, and the former has neurologic disabilities unlike ASDs. There is evidence of dysregulated immune system early in life in both conditions. Lack of microglial phagocytosis and decreased levels of BDNF appear to distinguish Rett syndrome from ASDs, in which there is instead microglia activation and/or proliferation and possibly defective BDNF signaling. Moreover, brain mast cell (MC) activation and focal inflammation may be more prominent in ASDs than Rett syndrome. The flavonoid luteolin blocks microglia and MC activation, provides BDNF-like activity, reverses Rett phenotype in mouse models, and has a significant benefit in children with ASDs. Appropriate formulations of luteolin or other natural molecules may be useful in the treatment of Rett syndrome.
authors: Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA; Department of Internal Medicine, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA; Tufts Medical Center, Boston, MA, USA; Department of Psychiatry, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA. Electronic address: theoharis.theoharides@tufts.edu.
authors: Theoharis C
authors: TC
authors: Theoharides
authors: Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA.
authors: Marianna
authors: M
authors: Athanassiou
authors: Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA.
authors: Smaro
authors: S
authors: Panagiotidou
authors: Pediatric Psychopharmacology Unit, Massachusetts General Hospital, Boston MA, USA; Harvard Medical School, Boston MA, USA.
authors: Robert
authors: R
authors: Doyle
mesh_terms: D001921:Brain / Q000276:immunology / Q000378:metabolism; D002659:Child Development Disorders, Pervasive / Q000235:genetics / Q000473:pathology*; D003346:Corticotropin-Releasing Hormone; D016207:Cytokines; D005260:Female; D006801:Humans; D008297:Male; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009414:Nerve Growth Factors / Q000378:metabolism*; D039781:PubMed / Q000706:statistics & numerical data; D015518:Rett Syndrome / Q000235:genetics / Q000473:pathology*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D016207:Cytokines; C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2; D009414:Nerve Growth Factors; D003346:Corticotropin-Releasing Hormone
keywords: Brain-derived neurotrophic factor; Inflammation; Mast cells; Microglia; Mitochondria; Rett syndrome; Treatment