Dr. Trotti Davide Trotti, Ph.D.

Contact Dr. Trotti

900 Walnut St.
Suite 451
Philadelphia, PA 19107

215-955-8416
215-503-9128 fax

University Appointment
Associate Professor (2009)

Research and Clinical Interests
Neurobiologist Davide Trotti has a long standing interest in understanding the mechanisms of neuronal cell death in neurodegenerative diseases.

High affinity glutamate transporters play a crucial role in the process of synaptic transmission and in the control of excitotoxic cell death. After release and interaction with its receptors, glutamate is removed from the synaptic cleft by uptake mechanisms. The maintenance of a low concentration of external glutamate is one obvious function of the glutamate transport systems. This function is crucial, as glutamate becomes neurotoxic when its extracellular concentration exceeds certain levels. A perturbed function at glutamatergic synapses has been implicated in many disease states, including brain ischemia, epilepsy and several human neurodegenerative disorders such as Amyotrophic Lateral Sclerosis (ALS).

Research in Dr. Trotti's laboratory is aimed at studying the molecular mechanisms of excitotoxicity leading to motor neuron degeneration in amyotrophic lateral sclerosis (ALS). ALS is the most common adult motor neuron disease and its primary hallmark is the death of motor neurons of the spinal cord which leads to spasticity, hyper-reflexia, general weakness and muscle atrophy. Failure of respiratory muscles is generally the fatal event, occurring within 1-5 years of symptoms onset. Impairment in the glutamate transport system and loss of the glutamate transporter GLT1 (a.k.a.EAAT2) are pathological events contributing to motor neuron death in ALS. Dr. Trotti's laboratory has accumulated expertise in the study of molecular mechanisms regulating glutamate transporter activity, expression and trafficking.

A second objective of Dr. Trotti's research is the study of mitochondria and the molecular mechanisms leading to their impaired physiology in ALS. Mitochondria are one of the main sources of energy production and play a pivotal role in maintaining neuronal cell alive. A pathology-driven impairment in these organelles may shift the balance between life and death and lead to neuronal degeneration.

A third objective of Dr. Trotti's research involve therapeutic approaches in ALS. High expression levels, multispecificity, and high transport potency makes the P-glycoprotein a selective gatekeeper of the brain and blood-brain barrier and thus a primary obstacle to drug delivery in the CNS. As such, P-glycoprotein limits CNS entry of a large number of drugs and xenobiotics, contributes to the poor success rate of CNS drug candidates, and probably contributes to patient-to-patient variability in response to CNS pharmacotherapy. Modulating P-glycoprotein could therefore improve drug delivery into the CNS and drug therapy. We propose to validate this concept in the context of ALS therapy.

CURRENT RESEARCH PROGRAMS:

1. Post-translational processing of the glial glutamate transporter EAAT2 in ALS
2. Mechanisms of mitochondria impairment in ALS
3. P-glycoprotein mediated chemoresistance in ALS therapy

Publications

Most recent Peer-reviewed Publications

  1. Selective increase of two ABC drug efflux transporters at the blood-spinal cord barrier suggests induced pharmacoresistance in ALS
  2. An over-oxidized form of superoxide dismutase found in sporadic amyotrophic lateral sclerosis with bulbar onset shares a toxic mechanism with mutant SOD1
  3. Motor neuron impairment mediated by a sumoylated fragment of the glial glutamate transporter EAAT2
  4. Voltage-dependent inwardly rectifying potassium conductance in the outer membrane of neuronal mitochondria
  5. ALS-linked mutant SOD1 damages mitochondria by promoting conformational changes in Bcl-2
  6. Glutamate transporters and the excitotoxic path to motor neuron degeneration in amyotrophic lateral sclerosis
  7. Nordihydroguaiaretic acid increases glutamate uptake in vitro and in vivo: Therapeutic implications for amyotrophic lateral sclerosis
  8. A caspase-3-cleaved fragment of the glial glutamate transporter EAAT2 is sumoylated and targeted to promyelocytic leukemia nuclear bodies in mutant SOD1-linked amyotrophic lateral sclerosis
  9. Caspase-3 cleaves and inactivates the glutamate transporter EAAT2
  10. Amyotrophic lateral sclerosis-associated SOD1 mutant proteins bind and aggregate with Bcl-2 in spinal cord mitochondria
  11. Modulation of DMT1 Activity by Redox Compounds
  12. A role for glutamate transporters in neurodegenerative diseases
  13. Neutral amino acid absorption in the midgut of lepidopteran larvae
  14. Regulation of glutamate transporters in health and disease
  15. Inhibition of the glutamate transporter EAAC1 expressed in Xenopus oocytes by phorbol esters
  16. Amyotrophic lateral sclerosis-linked glutamate transporter mutant has impaired glutamate clearance capacity
  17. Specific linoleate deficiency in the rat does not prevent substantial carbon recycling from [14C]linoleate into sterols
  18. Erratum: SOD1 mutants linked to amyotrophic lateral sclerosis selectively inactivate a glial glutamate transporter (Nature Neuroscience (1999) 2 (247-433))
  19. SOD1 mutants linked to amyotrophic lateral sclerosis selectively inactivate a glial glutamate transporter
  20. Inhibitory effect of the neuroprotective agent idebenone on arachidonic acid metabolism in astrocytes

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