Increased GABAergic development in iPSC-derived neurons from patients with sporadic Alzheimer's disease
NEUROSCIENCE LETTERS
Authors: Tang, Yueyu; Han, Yingying; Yu, Hongxiang; Zhang, Bei; Li, Gang
Abstract
Alzheimer's disease (AD) is the most common cause of dementia in the elderly, and the underlying molecular mechanisms of this neurodegenerative disorder are still unclear. gamma-Aminobutyric acid (GABA) neurons play an essential role in the excitatory/inhibitory (E/I) balance in the brain, and the GABAergic system may contribute to the pathogenesis of AD. We used human induced pluripotent stem cells (iPSCs) generated from sporadic AD (SAD) patients to analyze the phenotype and transcriptional profiles of SAD iPSC-derived neural cells. We observed reduced neurogenesis and increased astrogenesis in SAD neural differentiation. We discovered elevated levels of GABA, glutamate decarboxylase 67 (GAD67), and vesicular GABA transporter (vGAT) in SAD neurons that indicated increased GABAergic development. Gene expression profiling of SAD neural cultures showed upregulation of the GABAergic signaling pathway and downregulation of the neurogenesis pathway. We presumed that the GABAergic transmission system might be enhanced in SAD neurons, as an early pathological change of SAD, which provides a novel target and new direction for the development of more effective therapeutic strategies.
Emerging therapeutic targets for schizophrenia: a framework for novel treatment strategies for psychosis
EXPERT OPINION ON THERAPEUTIC TARGETS
Authors: Sonnenschein, Susan F.; Grace, A.
Abstract
Introduction: Antipsychotic drugs are central to the treatment of schizophrenia, but their limitations necessitate improved treatment strategies. Multiple lines of research have implicated glutamatergic dysfunction in the hippocampus as an early source of pathophysiology in schizophrenia. Novel compounds have been designed to treat glutamatergic dysfunction, but they have produced inconsistent results in clinical trials. Areas covered: This review discusses how the hippocampus is thought to drive psychotic symptoms through its influence on the dopamine system. It offers the reader an evaluation of proposed treatment strategies including direct modulation of GABA or glutamate neurotransmission or reducing the deleterious impact of stress on circuit development. Finally, we offer a perspective on aspects of future research that will advance our knowledge and may create new therapeutic opportunities. PubMed was searched for relevant literature between 2010 and 2020 and related studies. Expert opinion: Targeting aberrant excitatory-inhibitory neurotransmission in the hippocampus and its related circuits has the potential to alleviate symptoms and reduce the risk of transition to psychosis if implemented as an early intervention. Longitudinal multimodal brain imaging combined with mechanistic theories generated from animal models can be used to better understand the progression of hippocampal-dopamine circuit dysfunction and heterogeneity in treatment response.