Novel Optical Imaging Probe for the Targeted Visualization of NLRP3 Inflammasomes in Living Retina

Area of Science:

• Ophthalmology
• Molecular Imaging
• Immunology

Background:

• Diabetic retinopathy progression is linked to the activation of the NLR-family pyrin domain-containing 3 (NLRP3) inflammasome.
• Early detection of NLRP3 inflammasome activation is crucial for managing diabetic retinopathy.

Purpose of the Study:

• To develop and evaluate InflammaProbe-2, a novel molecular imaging probe for in vivo visualization of NLRP3 inflammasomes.
• To assess InflammaProbe-2's efficacy and safety as an early diagnostic tool for diabetic retinopathy.

Main Methods:

• Synthesis of InflammaProbe-2, a highly sensitive molecular imaging probe.
• Enzyme-linked immunosorbent assay (ELISA) to assess InflammaProbe-2's ability to inhibit NLRP3-mediated IL-1β secretion.
• In vitro studies using ARPE-19 cells under hyperglycemia and inflammatory conditions.
• In vivo and ex vivo fluorescence imaging in streptozotocin (STZ)-induced diabetic retinopathy models.
• In vitro and in vivo toxicity assessments.

Main Results:

• InflammaProbe-2 successfully visualized NLRP3 inflammasomes in ARPE-19 cells under hyperglycemic and inflammatory conditions.
• In vivo and ex vivo imaging demonstrated InflammaProbe-2's ability to detect NLRP3 inflammasomes in STZ-induced diabetic retinopathy via fluorescence enhancement.
• InflammaProbe-2 exhibited no significant toxicity, with no adverse effects on retinal electrical responses (a-wave and b-wave amplitudes).

Conclusions:

• InflammaProbe-2 is a sensitive and safe molecular imaging probe for early in vivo detection of NLRP3 inflammasomes in diabetic retinopathy.
• This probe holds potential as a valuable diagnostic tool for monitoring disease progression and therapeutic responses.