LEANDRA FIGUEROA-HALL

The Figueroa-Hall Laboratory

Neuro-Glia Immunopsychiatry Research Lab (NeuroGIRL)

Our Research Approach

Inflammation is thought to play a role in the pathogenesis of major depressive disorder (MDD), but the exact immunoregulatory mechanisms are not well understood. Dr. Figueroa-Hall’s training and expertise in toll-like receptor 4 (TLR4) inflammatory signaling is the basis for her research interests in examining how the TLR4 system via regulating inflammatory processes affects mental health. Her overarching goal is to understand how the immune system is dysregulated in MDD and identify novel targets/biomarkers for inflammation-associated depression.

Current research aims:

Investigate peripheral and central immune responses in depressed vs. healthy individuals
Delineate astrocyte-enriched EV-mediated immune mechanisms in MDD
Identify differences in peripheral and central inflammation-related microRNAs in MDD

Dr. Figueroa-Hall’s research is currently funded by the Laureate Institute for Brain Research (LIBR) and the National Institute of Mental Health (R00MH126950: In vivo inflammatory challenge to elucidate the role of toll-like receptor 4 pathway in depression).

CONTACT DR. FIGUEROA-HALL

Research Program Highlights

Main Question

How does the body’s response to fighting off external or internal agents via the TLR4 system possibly result in depression? This question is based on the premise that the body’s response to external agents (i.e., viruses and bacteria) and internal (i.e., cellular contents released due to stressors) agents not only affects the body but also the brain, possibly leading to depression as one of its consequences.

Approach

With the use of molecular and genetic techniques, Dr. Figueroa-Hall is now investigating central mechanisms with the isolation of brain-enriched extracellular vesicles (EV), specifically, astrocyte-enriched EV (AEEV). The study of brain-enriched (EV) provides a unique, and possibly, revolutionary approach to examine brain biology from a blood sample. Specifically, AEEV are a window into one of the brain’s immune mechanisms to activating the TLR4 system and will help to determine whether the degree of brain response is associated with changes in mental health.

Future Directions

Dr. Figueroa-Hall’s laboratory will aim to 1) elucidate TLR4-mediated inflammatory mechanisms in opioid use disorder; 2) elucidate the role of damage-associate molecular patterns (internal agents) in MDD and other psychiatric disorders; and 3) identify/validate microglial-specific maker (s) for isolation of microglial-enriched EV and investigation of their role in mental health pathophysiology.

Scientific Background

Dr. Figueroa-Hall was born in Warner Robins, GA and raised in St. Croix, US Virgin Islands. She received her B.Sc. in Biology from the University of the Virgin Islands, her M.Sc. in Biomedical Research with a focus on molecular mechanisms of toll-like receptor 4 (TLR4) signaling from the University of Maryland, School of Medicine (SOM), and her Ph.D. in Biomedical Sciences with a concentration in TLR4 neuroinflammatory signaling from Oklahoma State University, Center for Health Sciences. After obtaining her doctorate, she completed a two-year postdoctoral fellowship at Yale University SOM, gaining experience in translational-based research and cutting-edge techniques.

Dr. Figueroa-Hall joined LIBR in 2019 as a Postdoctoral Research Associate under the mentorships of Dr. Jonathan Savitz and Dr. Martin Paulus. Dr. Figueroa-Hall was promoted to Associate Investigator in 2022 and promoted to Principal Investigator in 2024. Her current research focuses on elucidating immune mechanisms in MDD.