Islet cells metabolism and viability probing with non-label optical diagnostics
Alexandra Kashina1, Polina Bardina1, Irina Kornilova1, Emil Kryukov1, Vadim Elagin1, Varvara Dudenkova1, Alena Kashirina1, Denis Kuchin3, Elena Zagaynova1,2, Vladimir Zagainov3,4.
1Privolzhsky Research Medical University, Institute of Experimental Oncology and Biomedical Technologies, Nizhny Novgorod, Russian Federation; 2Lobachevsky State University of Nizhny Novgorod, Institute of Biology and Biomedicine, Nizhny Novgorod, Russian Federation; 3Privolzhsky Federal Medical Center, Organ Transplant Department, Department of Surgery, Nizhny Novgorod, Russian Federation; 4Privolzhsky Research Medical University, Department of University Surgery and Transplantology, Nizhny Novgorod, Russian Federation
Isolation of sufficient amount of high–quality islets from pancreas is prerequisite for successful islet auto- and allotransplantation. However, the problem of islets quality assessing in the whole tissue and isolated islet cells without destroying the cell and tissue structure and using exogenous dyes has not yet been solved. The use of metabolic imaging technologies based on FLIM (fluorescence lifetime detection microscopy) and autofluorescence of intracellular metabolite NAD(P)H open up the wide possibilities for non-invasive and non-contrast diagnostics of the pancreatic islet cells quality and the number of viable and metabolically active islets.
In this study based on FLIM and intracellular metabolite NAD(P)H was developed non-invasive and label-free method of the quality assessment of human pancreatic islets in tissue and isolated islet cells. Using the FLIM approach and NAD(P)H we tested the effect of the storage time of human pancreas on the islets viability and metabolism preservation. In addition, we checked FLIM opportunity to assess the islet cells quality in the pathological and normal pancreas.
We revealed that islets in the pancreas samples, analyzed 1-2 hours after collection, were characterized by FLIM data corresponds more glycolytic status compared to islets in samples analyzed 8 or more hours after collection. We supposed that these metabolic status changes of islet cells may be associated with the destruction and further cell death of islets, analyzed 8 and more hours after collection. Moreover, we found that FLIM parameters of islet cells in the pathological and normal pancreas were different. These metabolic differences may be related with insulin synthesis violation in the islet cells of the pathological pancreas. Metabolic FLIM imaging also was successfully applied to assess the isolated islet cells metabolism and viability. The isolated islets were characterized by typical for NAD(P)H fluorescence lifetimes which indicates the viability and metabolically active status of the islets after their isolation.
Non-contrast FLIM diagnostics can be used both to obtain new FLIM criteria for the identification of islet cells quality and metabolism and to develop a rapid technique for islets viability analysis in order to help for islets transplantation in clinic.
This work has been financially supported by the Ministry of Health of the Russian Federation (state assignment № АААА-А20-120022590096-6). .