# Targeting glutamate carboxypeptidase in perinatal brain injury

> **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2020 · $408,400

## Abstract

Targeting glutamate carboxypeptidase in perinatal brain injury
Project summary/abstract
Neuroinflammation and excitotoxicity, mediated by activated astrocytes and microglia, are major
pathophysiological mechanisms implicated in maternal inflammation induced brain injury in the perinatal
period, resulting in neurodevelopmental disorders such as cerebral palsy (CP). We hypothesize that targeting
both these mechanisms will provide maximum neuroprotection and enable normal development. We propose
to achieve this by targeting the enzyme glutamate carboxypeptidase II (GCPII), using the potent, selective
GCPII inhibitor 2-(3-mercaptopropyl) pentanedioic acid (2-MPPA), in our established rabbit model of maternal
inflammation induced CP. Capitalizing on our novel finding that GCPII is selectively upregulated in activated
microglia in newborn rabbits with CP, we will deliver 2-MPPA using dendrimer nanoparticles (D-MPPA),
specifically to these cells, thereby improving efficacy and reducing peripheral side effects. Inhibition of GCPII
will not only prevent hydrolysis of glutamate from the neuropeptide, but will also increase NAAG levels which
can independently exert neuroprotective effects by preventing pre-synaptic glutamate release and by
increasing synthesis and release of TGF-β1, which in turn promotes normal microglial function and exerts anti-
inflammatory effects. Our preliminary studies demonstrate that: (1) Neonatal rabbits with CP have increased
brain glutamate levels, microglial `activation' with restrictive microglial migration, and decreased TGF-β1 in the
brain, (2) D-MPPA selectively localizes in activated microglia and astrocytes in newborn rabbits with CP but
not in controls (3) D-MPPA is more effective than the drug alone in decreasing extracellular glutamate and in
increasing TGF-β1 levels in ex vivo brain slices and in mixed glial cultures exposed to LPS, and in improving
short-term motor deficits in rabbit kits with CP. Based on these promising results we hypothesize that, inhibition
of GCPII by D-MPPA specifically in activated microglia and astrocytes will decrease inflammation, improve
microglial morphology and migration, and decrease neuronal and white matter injury, resulting in improvement
in motor and cognitive deficits that persist until adulthood, in newborn rabbits with CP. To test this we will (1)
Assess the dose-dependent pharmacokinetics and pharmacodynamics in CP and control rabbit kits. (2)
Determine the role of D-MPPA and TGF-β1 in improving microglial morphology and migration in ex vivo brain
slices from rabbits with CP and (3) Evaluate the short term and long term efficacy of treatment with intravenous
D-MPPA in male and female rabbit kits with CP. The proposed work is innovative because it is the first study
that is focused on a nanotechnology based approach to target GCPII specifically in activated microglia
following brain injury. It takes advantage of the selective localization of dendrimers at sites of inflammation, ...

## Key facts

- **NIH application ID:** 9923754
- **Project number:** 5R01NS093416-05
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Sujatha Kannan
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $408,400
- **Award type:** 5
- **Project period:** 2016-09-15 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9923754

## Citation

> US National Institutes of Health, RePORTER application 9923754, Targeting glutamate carboxypeptidase in perinatal brain injury (5R01NS093416-05). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/9923754. Licensed CC0.

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