Presentation on theme: "New Research on Brain Energy in Mood and Psychotic Disorders Bruce M. Cohen, M.D., Ph.D. Director, Shervert Frazier Research Institute, McLean Hospital."— Presentation transcript:
New Research on Brain Energy in Mood and Psychotic Disorders Bruce M. Cohen, M.D., Ph.D. Director, Shervert Frazier Research Institute, McLean Hospital President and Psychiatrist in Chief Emeritus, McLean Hospital Robertson-Steele Professor of Psychiatry, Harvard Medical School NAMI-MA October 30, 2010
Relevant Financial Relationships: None
Relevant Personal Relationships: Many
Suzann Babb, M.S. Jin Kim, B.A. Tom Berry, B.A.Nick Lange, Sc.D. Brian Brennan, M.D. Eve Lewandowski. Ph.D. Anne Carpenter, Ph.D. David Logan, Ph.D. Anne Cataldo, Ph.D. Jeanne Lothrop, B.S. Bruce M. Cohen, M.D., Ph.D. Julie McCarthy, B.A. Diane Damez-Werno, B.A. Donna McPhie, Ph.D. Joe DePaola, B.A. Emily Mensale, B.A. Sarah Elmiligy, B.A. Beth Murphy, M.D., Ph.D. Laura Flynn, B.A. Dost Öngür, M.D., Ph.D. Brent Forester, M.D. Caitlin Ravichandran, Ph.D. Jennifer Gelda, B.A. Laura Sargent, B.A. Linda Hassinger, M.S. Jordan Smoller, M.D., Sc.D. Hannah Irving, B.A. Nancy Ye, Ph.D. List of Investigators Working on Project
A Caveat: Bipolar disorders and other psychiatric disorders are not homogeneous or unitary by cause or pathophysiology. They are likely the consequence of the interaction of numerous factors, both inherited and environmental, which differ from person to person.
Problems in energy production may be one factor contributing to the risk of developing bipolar or other brain disorders
Energy production and brain disorders Background:
Blood Flow and Metabolism of the Human Brain in Health and Disease Seymour S. Kety, M.D. “The blood flow of the brain represents about one-sixth of the cardiac output and its oxygen consumption nearly one quarter of that of the entire body.” Trans Stud Coll Physicians Phila Dec;18:103-8.
Seymour S. Kety, M.D. Energy use of the brain changes little, even in illness, except under extreme circumstances, such as coma. The brain maintains energy production within a narrow margin.
The brain uses ten times more energy per unit weight than the rest of the body Even subtle abnormalities of energy metabolism can affect brain function Energy abnormalities have been observed in many disorders of the brain
Why Is the Brain So Energy Dependent?
The Brain is a High-Precision Electro-Chemical Organ The brain must not only generate, but must quite accurately control, numerous electrical and chemical signals. Each of these tasks is highly energy expensive, and the energy must be made close to where it is used.
Pellerin and Magistretti, Science 2004
Raichle & Mintun, 2006 Nearly 99% of the energy production of the brain is used to support intrinsic (resting) activity. It is energy expensive just to support the basic background state and maintenance work of the brain.
Where Does the Brain Get Its Energy?
Most of the energy produced to support the work of the brain comes from oxidative phosphorylation, the complete ‘burning’ (oxidation) of glucose (sugar) to carbon dioxide and water. Oxidative phosphorylation occurs in, and only in, subcellular organelles called mitochondria.
Energy Production and Bipolar Disorders
A variety of early studies, including: Genetic In vivo brain imaging Post mortem gene expression Peripheral cell gene expression CSF metabolite studies All suggest abnormalities of energy metabolism in patients with bipolar disorder
We looked directly at mitochondria of patients with bipolar disorders. We studied both brain and peripheral cells from public tissue banks.
Mitochondrial Distribution in Brain Cells (Post Mortem-Cytochrome C Staining) Magnification 1,000X CONTROLBIPOLAR DISEASE
BD Brains Have More Smaller Mitochondria Than Control Brains (p<0.03) BD Contro l Area in Square Microns Number of Mitochondria
Mitochondrial Shape Abnormalities in Post Mortem Brain Tissue CONTROL BIPOLAR DISORDER EM Magnification 15,000X
Can We See Abnormalities in Peripheral Cells?
Is There an Abnormality of Mitochondrial Distribution in Peripheral Cells, as Observed in Brain, in BD?
Mitochondria Look Abnormal in Fibroblasts from Patients with Bipolar Disorder Mitochondria from fibroblasts in patients with bipolar disorder show an altered morphology consisting of short, thickened profiles that are arranged in a predominantly perinuclear location compared to age-matched controls.
Mitochondrial Network in Control and BD Lymphocytes Light Microscopy Magnification 1,000X
Quantification of Mitochondrial Distribution in Fibroblasts
Quantification of Changes in Mitochondrial Distribution BD vs Control, p< BD vs. Control, p<0.0008
Are there more or fewer mitochondria in BD?
No Difference in Total Mitochondrial Area Between Bipolar Disorder and Control Fibroblasts 0 20,000 40,000 60,000 80, , , ,000 ControlBD Square Pixels
Is the Difference in Distribution of Mitochondria in BD a Drug Effect? (There was a wide assortment of drugs taken by the subjects. Lithium was used by only half, and its use was not correlated with the mitochondrial abnormalities observed.)
Lithium Does Not Make Healthy Subject’s Cells Look Sick or BD Cells Look Healthy No Treatment 1mM Li2+ Control BD
Are There Abnormalities of Mitochondrial Shape in Peripheral Cells, as Observed in Brain, in BD?
Spherical and Cup Shaped Mitochondria in BD Fibroblasts BDBD Magnification 1,000X EM Magnification 10,000X
Quantification of Ring Shaped Mitochondria in Control and BD Fibroblasts Ultrastructural images from thirty fibroblasts were obtained at random (magnification 10,000X by electron microscopy) from each of 4 healthy controls and 4 BD cell lines (in total, 120 controls fibroblasts and 120 BD fibroblasts). We found that the number of ring structures was increased in cells from the BD patients compared to controls (Controls 1, per cell, p<0.01).
Is There a Functional Abnormality of Mitochondria in Peripheral Cells in Bipolar Disorder?
Mitochondrial Membrane Potential Staining (JC1) in Control and BD Fibroblasts CONTROL BIPOLAR DISEASE Red = Healthy Mitochondria Green = Compromised Mitochondria with lower membrane potential
Are These Abnormalities Specific to BD?
Schizophrenic Patient’s Fibroblasts May Exhibit Distinct Mitochondrial Abnormalities Control Bipolar DisorderSchizophrenia Magnification 630X
While consistent and from multiple sources, all of the evidence for abnormalities of energy production or mitochondrial shape and location in bipolar or related disorders is subtle, preliminary and needs confirmation HOWEVER:
Future Directions: Much More To Do By computerized analyses, we are determining many features of the shape and distribution of the mitochondrial network in our samples. With electron microscopy, we have begun to look at individual mitochondria in our samples. We are studying mitochondrial function at McLean and in collaboration with local colleagues.
Future Directions: Genetics The risk of psychiatric illnesses is highly determined by genetic factors. Given our findings, might some of the genes associated with bipolar disorders and schizophrenias be genes for mitochondrial form and function?
Many diseases are associated with abnormal levels or activities of the proteins which perform cell functions. We have begun to look directly at proteins known to be involved in determining mitochondrial location, shape and activity. Future Directions: Proteins
MITOCHONDRIAL MORPHOLOGICAL ABNORMALITIES DYSREGULATION OF FUSION AND FISSION PROTEINS, WHICH CONTROL MITOCHONDRIAL SHAPE, e.g. DRP1, ORA1 DYSREGULATION OF MOTOR PROTEINS, WHICH MOVE MITOCHONDRIA IN THE CELL, e.g.MIRO, MISATO, MYOSIN V DYSREGULATION OF CYTOSKELETAL PROTEINS, TO WHICH MITOCHONDRIA ATTACH, e.g. ACTIN, TUBULIN
There are no Large Scale Changes in the Actin Cytoskeleton in BD Green = Mitochondria Red = Actin Blue = Nuclei
No Overall Changes are Seen in the Tubulin Cytoskeleton in BD Control BD Red/Orange = mitochondria Green = Tubulin
Clinical trials: We are testing agents believed to increase mitochondrial function Brian Brennan et al - Acetyl-L-carnitine and alpha lipoic acid for bipolar depression Brent Forrester et al - Coenzyme Q10 for geriatric bipolar depression
Can mitochondria be repaired or replaced?
Some Developing Technologies for Neurorepair Gene Alteration Nanomedicine Organelle Replacement / Repair Cell Replacement / Repair Biofeedback and Cognitive Training
Healthy mitochondria can be isolated from blood cells and might be used to replace dysfunctional mitochondria in damaged cells Mitochondrial Transplantation
The Meaning of Our Results Abnormalities of mitochondrial form, distribution and function may be important factors in determining risk for mood and psychotic disorders. If so, we should be able to identify the causes of those mitochondrial abnormalities and use that knowledge to design better treatments and preventive measures for psychiatric illnesses.
To all my colleagues who worked, and keep working, so hard and well on these projects. (Anne would be pleased.) THANKS To NAMI, for all it’s work to improve lives, advance knowledge and improve our society. Good science and good lives are collaborations.
Art and Science: The Paintings of Lynda Cutrell