David Williams Laboratory

Roni A. Hazim

Project Scientist

Roni is a retinal cell biologist whose research focuses on understanding how intracellular transport, organelle organization, and mitochondrial metabolism regulate the specialized architecture and function of the retinal pigment epithelium (RPE), a layer of cells essential for supporting the light-sensitive photoreceptors. The aim of his research is to provide insights into the cellular mechanisms that maintain RPE health and to understand how their disruption may contribute to RPE pathologies and retinal degeneration.

Nan Hultgren(she/her)

Assistant Project Scientist

Nan studies how intracellular organelle dynamics and metabolic organization enable the retinal pigment epithelium (RPE) to support photoreceptor function and maintain retinal homeostasis. Her current work focuses on how mitochondrial positioning and inter-organelle interactions coordinate lipid processing during the daily phagocytosis of photoreceptor outer segments. Using advanced live-cell imaging, metabolic profiling, and disease-relevant RPE models, she studies how mitochondria, the endoplasmic reticulum, and lipid droplets dynamically interact to manage the substantial lipid load associated with photoreceptor renewal. Her work further examines how disruption of these processes contributes to lipid dysregulation and retinal degeneration.

Yuekan Jiao

Specialist

Dr. Jiao focuses on biological electron microscopy, super-resolution light microscopy and image analysis. His responsibilities include running, supporting and training with the microscopes; supporting with ImageJ and Imaris; and developing ImageJ plugins. Dr. Jiao also conducts eye research through collaborating with research labs.

Antonio E. Paniagua

Assistant Project Scientist

Antonio studies how photoreceptors build and renew their outer segments. His work focuses on how new disk membranes are formed at the base of the outer segment and how the retinal pigment epithelium ingests and degrades outer segment tips. His expertise includes 3D electron tomography, STED and SIM super-resolution microscopy, live-cell imaging, subretinal AAV delivery, and neonatal retinal electroporation. He held an independent BrightFocus Foundation postdoctoral fellowship (Elizabeth Anderson Award for Macular Degeneration Research, 2021-2023) and currently participates as Co-Investigator in two NIH-NEI R01 grants.