NADH distribution in live progenitor stem cells by phasor-fluorescence lifetime image microscopy

Area of Science:

• Cellular Biology
• Biophysics
• Metabolomics

Background:

• Nicotinamide adenine dinucleotide (NADH) is a crucial metabolite in cellular respiration and exhibits natural fluorescence.
• The fluorescence lifetime of NADH differs between its free and bound states within cells.
• Quantifying free and bound NADH can provide insights into cellular processes like apoptosis, cancer, and enzyme kinetics.

Purpose of the Study:

• To spatially map the distribution of free and bound NADH in live undifferentiated and differentiated myoblast cells.
• To utilize the phasor-fluorescence lifetime image microscopy (FLIM) approach for NADH analysis.
• To investigate changes in NADH distribution during cellular differentiation.

Main Methods:

• Phasor-fluorescence lifetime image microscopy (FLIM) was employed to analyze NADH.
• The phasor approach allowed for pixel-level mapping of NADH lifetime without decay fitting.
• Live undifferentiated and differentiated myoblast cells were studied.

Main Results:

• Distinct spatial distributions of free and bound NADH were observed between undifferentiated and differentiating myoblast cells.
• Undifferentiated cells showed free NADH (short lifetime) in the nucleus and bound NADH (long lifetime) in the cytoplasm.
• Differentiating cells exhibited a redistribution of NADH, with decreased nuclear free NADH and increased cytoplasmic NADH.

Conclusions:

• Phasor-FLIM is effective for spatially mapping free and bound NADH in live cells.
• Cellular differentiation in myoblasts leads to significant redistribution of NADH.
• Understanding NADH dynamics is critical for studying cellular respiration and related pathologies.