The nervous system has extremely complex RNA processing regulation. Dysfunction of RNA metabolism has emerged to play crucial roles in multiple neurological diseases. Mutations and pathologies of several RNA-binding proteins are found to be associated with neurodegeneration in both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). An alternative RNA-mediated toxicity arises from microsatellite repeat instability in the human genome. The expanded repeat-containing RNAs could potentially induce neuron toxicity by disrupting protein and RNA homeostasis through various mechanisms. The Sun Lab is interested in deciphering the RNA processing pathways altered by the ALS-causative mutants to uncover the mechanisms of toxicity and molecular basis of cell type-selective vulnerability. Another major focus of the group is to identify small molecule and genetic inhibitors of neuron toxic factors using various high-throughput screening platforms. Finally, we are also highly interested in developing novel CRISPR technique-based therapeutic strategies. We seek to translate the mechanistic findings at molecular level to therapeutic target development to advance treatment options against neurodegenerative diseases.

The Barouch Lab is focused on defining the peripheral cardiovascular effects of the adipocytokine leptin, which is a key to the understanding of obesity-related cardiovascular disease. Interestingly, many of the hormonal abnormalities seen in obesity are mimicked in heart failure. The research program will enhance the understanding of metabolic signaling in the heart, including the effects of leptin, exercise, sex hormones, and downstream signaling pathways on metabolism and cardiovascular function. The lab also is working to determine the precise role of the “metabolic” beta-3 adrenergic receptor (ß3AR) in the heart and define the extent of its protective effect in obesity and in heart failure, including its role in maintaining nitric oxide synthase (NOS) coupling. Ultimately, this work will enable the exploration of a possible therapeutic role of ß3AR agonists and re-coupling of NOS in preventing adverse ventricular remodeling in obesity and in heart failure. Lili Barouch, MD, is an associate professor of medicine in the Division of Cardiology and a member of the Advanced Heart Failure and Cardiac Transplantation group at the Johns Hopkins University School of Medicine.

Dr. Hua's research has centered on the development of novel MRI technologies for in vivo functional and physiological imaging in the brain, and the application of such methods for studies in healthy and diseased brains. These include the development of human and animal MRI methods to measure functional brain activities, cerebral perfusion and oxygen metabolism at high (3 Tesla) and ultra-high (7 Tesla and above) magnetic fields. He is particularly interested in novel MRI approaches to image small blood and lymphatic vessels in the brain. Collaborating with clinical investigators, these techniques have been applied 1) to detect functional, vascular and metabolic abnormalities in the brain in neurodegenerative diseases such as Huntingdon's disease (HD), Parkinson's disease (PD), Alzheimer's disease (AD) and mental disorders such as schizophrenia; and 2) to map brain functions and cerebrovascular reactivity for presurgical planning in patients with vascular malformations, brain tumors and epilepsy.

Work in the Courtney Robertson Lab is focused on identifying interventions that could minimize the neurological deficits that can persist after pediatric traumatic brain injury (TBI). One study used a preclinical model to examine potential disruption of mitochondrial function and alterations in cerebral metabolism. It was found that a substantial amount of mitochondrial dysfunction is present in the first six hours after TBI. In addition, we are using nuclear magnetic resonance spectroscopy to evaluate global and regional alterations in brain metabolism after TBI. We're also collaborating with researchers at the University of Pennsylvania to compare mitochondrial function after head injury in different clinically relevant models.

A. Laboratory activities include the use of accelerator mass spectrometry (AMS) techniques to measure intracellular drugs and drugs metabolites. AMS is a highly sensitive method for detecting tracer amounts of radio-labeled molecules in cells, tissues, and body fluids. We have been able to measure intracellular zidovudine triphosphate (the active anabolite of zidovudine) in peripheral blood mononuclear cells from healthy volunteers given small doses of 14C-zidovudine, and have directly compared the sensitivity of AMS to traditional LC/MS methods carried out in our laboratory. B. Clinical research activities investigate the clinical pharmacology of new anti-HIV therapies and drug combinations. Specific drug classes studied include HIV reverse transcriptase inhibitors, protease inhibitors, entry inhibitors (selective CCR5 and CXCR4 antagonists), and integrase inhibitors. Scientific objectives of clinical studies include characterization of early drug activity, toxicity, and pharmacokinetics. Additional objectives are characterization of pathways of drug metabolism, and identification of clinically significant harmful and beneficial drug interactions mediated by hepatic and intestinal cytochrome P450 isoforms.