Published online Oct 27, 2022. doi: 10.4254/wjh.v14.i10.1884
Peer-review started: July 26, 2022
First decision: August 18, 2022
Revised: September 2, 2022
Accepted: October 2, 2022
Article in press: October 2, 2022
Published online: October 27, 2022
Processing time: 93 Days and 2 Hours
Determining the fate of transplanted cells in vivo through long-term cell tracking remains a crucial field of investigation. Long-term live cell tracking in vivo has always been challenging due to the absence of a safe cell-labeling agent.
DiD is a carbocyanine dye having good photochemical properties of strong fluorescence, and stability. Due to the long-range emission of DiD (670 nm), tissue autofluorescence is minimum, permitting the use of other fluorochromes such as fluorescein isothiocyanate, for colocalization studies to evaluate the expression of other essential markers specific to the transplanted cells in the recipient tissue. Moreover, the process for labeling the cells using DiD is easy due to its excellent efficiency for integration and diffusion into the cell membranes. The effects of DiD labeling on in vivo retention of labeled human liver cells remain to be investigated.
The present study aimed to shed light on the fate of DiD-labeled human liver cells in chronic liver diseases (CLD)-severe combined immunodeficiency (SCID) mice using live imaging up to 80 d post-transplantation.
A chronic liver disease SCID mouse model was developed, which received DiD-labeled EpCAM-positive human hepatic progenitor cells by intra-hepatic infusion. The long-term survival and functional response of transplanted DiD-labeled cells were investigated up to 80 d.
This study showed that DiD labeling of human liver cells is easy and efficient for long-term and non-invasive tracking in vivo up to 80 d post-transplantation. Using DiD, the fate of transplanted cells was determined. Transplanted human fetal liver cells were able to provide structural and functional improvement in CLD-SCID mice.
Monitoring the fate of transplanted cells through DiD-based in vivo live cell imaging can help in understanding the homing, engraftment, long-term survival, and function of the transplanted cells.
The findings of the current study may pave the way to unravel the underlying regenerative mechanisms and contribution of exogenously transplanted cells in restoring the structural and functional deficits of the liver in CLD.