Huntington's disease is a late-onset, autosomal dominant neurodegenerative disorder characterized by motor, cognitive and psychiatric symptomatology. The earliest stage of Huntington's disease is marked by alterations in gene expression, which partially results from dysregulated epigenetic modifications.
Alcoholism is a complex psychiatric disorder that has a multifactorial etiology. Epigenetic mechanisms are uniquely capable of accounting for the multifactorial nature of the disease in that they are highly stable and are affected by environmental factors, including alcohol itself. Chromatin remodeling causes changes in gene expression in specific brain regions contributing to the endophenotypes of alcoholism such as tolerance and dependence.
Stress response is considered to have adaptive value for organisms faced with stressful condition. Chronic stress however adversely affects the physiology and may lead to neuropsychiatric disorders. Repeated stressful events in animal models have been shown to cause long-lasting changes in neural circuitries at molecular, cellular, and physiological level, leading to disorders of mood as well as cognition.
Understanding the interaction between fear and reward at the circuit and molecular levels has implications for basic scientific approaches to memory and for understanding the etiology of psychiatric disorders. Both stress and exposure to drugs of abuse induce epigenetic changes that result in persistent behavioral changes, some of which may contribute to the formation of a drug addiction or a stress-related psychiatric disorder. Converging evidence suggests that similar behavioral, neurobiological and molecular mechanisms control the extinction of learned fear and drug-seeking responses.
Alcohol use and alcohol addiction represent dysfunctional brain circuits resulting from neuroadaptive changes during protracted alcohol exposure and its withdrawal. Alcohol exerts a potent effect on synaptic plasticity and dendritic spine formation in specific brain regions, providing a neuroanatomical substrate for the pathophysiology of alcoholism. Epigenetics has recently emerged as a critical regulator of gene expression and synaptic plasticity-related events in the brain.
Hormone-dependent gene expression requires dynamic and coordinated epigenetic changes. Estrogen receptor-positive (ER+) breast cancer is particularly dependent upon extensive chromatin remodeling and changes in histone modifications for the induction of hormone-responsive gene expression. Our previous studies established an important role of bromodomain-containing protein-4 (BRD4) in promoting estrogen-regulated transcription and proliferation of ER+ breast cancer cells.
Attention deficit/hyperactivity disorder (ADHD) is one of the most common psychiatric disorders of childhood. Despite its prevalence, the critical factors involved in its development remain to be identified. It was recently suggested that epigenetic mechanisms probably contribute to the etiology of ADHD. The present study was designed to examine the associations of epigenetic markers with ADHD among Chinese Han children, aiming to establish the prediction model for this syndrome from the epigenetic perspective.