An Aptamer-Based Near-Infrared Fluorescence Nanoprobe for Detecting and Imaging of PLN Micropeptide in Cardiomyocytes.

A growing body of evidence indicates that micropeptides encoded by long noncoding RNAs (lncRNAs) act independently or as regulators of larger proteins in fundamental biological processes, especially in the maintenance of cellular homeostasis. However, due to their small size and low intracellular expression, visual monitoring of micropeptides in living cells is still a challenge. In this work, we have designed and synthesized an aptamer-based near-infrared fluorescence nanoprobe for fluorescence imaging of phospholamban (PLN), which is an intracellular micropeptide that affects calcium homeostasis, and is closely associated with human heart failure in clinic. The nanoprobe could respond specifically to PLN with excellent selectivity, high sensitivity, good nuclease stability and biocompatibility, and it was successfully applied for imaging of changes in PLN levels in cardiomyocytes and in frozen section of heart tissues. And further combined with clinical myocardial biopsy, we believe that the developed nanoprobe should be of great significance in the later molecular pathology study of heart failure, which may help to assist diagnose early heart failure in the future. More importantly, it was for the first time to apply a nanoprobe for visually monitoring the changes of micropeptide in living cells and in frozen tissue sections, and the design concept of the aptamer-based nanoprobe can be extended for fluorescence detecting other micropeptides.