Abstract:Adipocytes are the main cell type in adipose tissue, which is a critical regulator of metabolism, highly specialized in storing energy as fat. Adipocytes differentiate from multipotent mesenchymal stromal cells (hMSCs) through adipogenesis, a tightly controlled differentiation process involving close interplay between metabolic transitions and sequential programs of gene expression. However, the specific gears driving this interplay remain largely obscure. Additionally, the metabolite nicotinamide adenine dinu… Show more
“…We tested FLUTE on a FLIM dataset acquired in human mesenchymal stromal cells (hMSCs) in vitro ( 61 ) to demonstrate the ability of the software to visualize the autofluorescence of the intrinsic biomarker NADH ( 73 , 79 ) and quantify metabolic states associated with subcellular compartments (Figure 5) and metabolic shifts associated with drug treatments (Figure 6). Figure 5. Fluorescence lifetime imaging microscopy (FLIM) analysis of NADH reveals intracellular metabolic heterogeneity in mesenchymal stromal cells.…”
Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique used to probe the local environment of fluorophores. The fit-free phasor approach to FLIM data is increasingly being used due to its ease of interpretation. To date, no open-source graphical user interface (GUI) for phasor analysis of FLIM data is available in Python, thus limiting the widespread use of phasor analysis in biomedical research. Here, we present Fluorescence Lifetime Ultimate Explorer (FLUTE), a Python GUI that is designed to fill this gap. FLUTE simplifies and automates many aspects of the analysis of FLIM data acquired in the time domain, such as calibrating the FLIM data, performing interactive exploration of the phasor plot, displaying phasor plots and FLIM images with different lifetime contrasts simultaneously, and calculating the distance from known molecular species. After applying desired filters and thresholds, the final edited datasets can be exported for further user-specific analysis. FLUTE has been tested using several FLIM datasets including autofluorescence of zebrafish embryos and in vitro cells. In summary, our user-friendly GUI extends the advantages of phasor plotting by making the data visualization and analysis easy and interactive, allows for analysis of large FLIM datasets, and accelerates FLIM analysis for non-specialized labs.
“…We tested FLUTE on a FLIM dataset acquired in human mesenchymal stromal cells (hMSCs) in vitro ( 61 ) to demonstrate the ability of the software to visualize the autofluorescence of the intrinsic biomarker NADH ( 73 , 79 ) and quantify metabolic states associated with subcellular compartments (Figure 5) and metabolic shifts associated with drug treatments (Figure 6). Figure 5. Fluorescence lifetime imaging microscopy (FLIM) analysis of NADH reveals intracellular metabolic heterogeneity in mesenchymal stromal cells.…”
Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique used to probe the local environment of fluorophores. The fit-free phasor approach to FLIM data is increasingly being used due to its ease of interpretation. To date, no open-source graphical user interface (GUI) for phasor analysis of FLIM data is available in Python, thus limiting the widespread use of phasor analysis in biomedical research. Here, we present Fluorescence Lifetime Ultimate Explorer (FLUTE), a Python GUI that is designed to fill this gap. FLUTE simplifies and automates many aspects of the analysis of FLIM data acquired in the time domain, such as calibrating the FLIM data, performing interactive exploration of the phasor plot, displaying phasor plots and FLIM images with different lifetime contrasts simultaneously, and calculating the distance from known molecular species. After applying desired filters and thresholds, the final edited datasets can be exported for further user-specific analysis. FLUTE has been tested using several FLIM datasets including autofluorescence of zebrafish embryos and in vitro cells. In summary, our user-friendly GUI extends the advantages of phasor plotting by making the data visualization and analysis easy and interactive, allows for analysis of large FLIM datasets, and accelerates FLIM analysis for non-specialized labs.
“…NAD + is a coenzyme in redox reactions, but also serves as a substrate of NAD + consuming enzymes which cleave NAD + to produce NAM and an ADP-ribosyl product, such as ADP-ribose transferases, cADP-ribose synthases and sirtuins (SIRT1-SIRT7) 103 , 134 , 135 . Indeed, both NAD + consumers SIRT1 46 , 136 , 137 and SIRT3 21 provide reciprocal regulation to the clock machinery to modulate circadian transcription and metabolism in the liver.…”
The circadian clock is an endogenous time-tracking system that anticipates daily environmental changes. Misalignment of the clock can cause obesity, which is accompanied by reduced levels of the clock-controlled, rhythmic metabolite NAD+. Increasing NAD+ is becoming a therapy for metabolic dysfunction; however, the impact of daily NAD+ fluctuations remains unknown. Here, we demonstrate that time-of-day determines the efficacy of NAD+ treatment for diet-induced metabolic disease in mice. Increasing NAD+ prior to the active phase in obese male mice ameliorated metabolic markers including body weight, glucose and insulin tolerance, hepatic inflammation and nutrient sensing pathways. However, raising NAD+ immediately before the rest phase selectively compromised these responses. Remarkably, timed NAD+ adjusted circadian oscillations of the liver clock until completely inverting its oscillatory phase when increased just before the rest period, resulting in misaligned molecular and behavioral rhythms in male and female mice. Our findings unveil the time-of-day dependence of NAD+-based therapies and support a chronobiology-based approach.
“…NAD + plays an indispensable role in OXPHOS by acting as a proton acceptor 62 . Along with its role in OXPHOS it also acts as a signaling molecule in many cellular pathways like cell growth 63 , sirtuin activity 64 , and cell differentiation 24,25,65 . There is an intimate connection between energy metabolism and redox cofactors 12 , and they appear on the front defense line in incidents of mitochondrial insult 66 , cellular stress 67 , nutrient depletion/starvation 12 , and high energy demand like during exercise 68 .…”
Mitochondrial carrier homolog 2 (MTCH2) is a regulator of apoptosis, mitochondrial dynamics, and metabolism. Loss of MTCH2 results in mitochondrial fragmentation, an increase in whole-body energy utilization, and protection from diet-induced obesity. We now show using temporal metabolomics that MTCH2 deletion results in a high ATP demand, an oxidized environment, a high lipid/amino acid/carbohydrate metabolism, and in the decrease of many metabolites. Lipidomics analyses show a strategic adaptive decrease in membrane lipids and an increase in storage lipids in MTCH2 knockout cells. Importantly, all the metabolic changes in the MTCH2 knockout cells were rescued by MTCH2 re-expression. Interestingly, this imbalance in energy metabolism and reductive potential triggered by MTCH2-deletion inhibits adipocyte differentiation, an energy consuming reductive biosynthetic process. In summary, loss of MTCH2 results in an increase in energy demand that triggers a catabolic and oxidizing environment, which fails to fuel the anabolic processes during adipocyte differentiation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
