A Novel Fluorogenic Probe Reveals Lipid Droplet Dynamics in ME/CFS Fibroblasts, 2024, Ding, Annesley et al

https://onlinelibrary.wiley.com/doi/full/10.1002/adsr.202300178

A Novel Fluorogenic Probe Reveals Lipid Droplet Dynamics in ME/CFS Fibroblasts

Siyang Ding, Oana Sanislav, Daniel Missailidis, Claire Yvonne Allan, Tze Cin Owyong, Ming-Yu Wu, Sijie Chen, Paul Robert Fisher, Sarah Jane Annesley, Yuning Hong
First published: 10 March 2024

https://doi.org/10.1002/adsr.202300178

Ding, S., Sanislav, O., Missailidis, D., Allan, C.Y., Owyong, T.C., Wu, M.-Y., Chen, S., Fisher, P.R., Annesley, S.J. and Hong, Y. (2024), A Novel Fluorogenic Probe Reveals Lipid Droplet Dynamics in ME/CFS Fibroblasts. Adv. Sensor Res. 2300178. https://doi.org/10.1002/adsr.202300178

Abstract

Lipid droplets (LDs) are dynamic cellular organelles that play an essential role in lipid metabolism and storage. LD dysregulation has been implicated in various diseases.

However, investigations into the cellular LD dynamics under disease conditions have been rarely reported, possibly due to the absence of high performing LD imaging agents.

Here a novel fluorogenic probe, AM-QTPA, is reported for specific LD imaging.

AM-QTPA demonstrates viscosity sensitivity and aggregation-induced emission enhancement characteristics.

It is live cell permeable and can specifically light up LDs in cells, with low background noise and superior signals that can be quantified.

After validation in cell model with LD accumulation induced by oleic acid treatment, AM-QTPA is applied in a small proof-of-concept number of human fibroblast samples derived from people diagnosed with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a complex and debilitating disease with unknown cause.

The results indicate the presence of larger but fewer LDs in ME/CFS fibroblasts compared to the healthy counterparts, accompanying with frequent LD-mitochondria contacts, suggesting potential upregulation of lipolysis in ME/CFS connective tissue like fibroblasts.

Overall, AM-QTPA provides new understanding of the anomalous LD dynamics in disease status, which, potentially, will facilitate in-depth investigation of the pathogenesis of ME/CFS.

 

References Phenotypic characteristics of peripheral immune cells of Myalgic encephalomyelitis/chronic fatigue syndrome via transmission electron microscopy: A pilot study (2022, PLOS ONE)

 

This study, the one quoted above by @SNT Gatchaman from 2022 and the following one from 1991 all noted Lipid droplets in ME/CFS. Seems like Lipid droplets deserves more research focus.
Mitochondrial abnormalities in the postviral fatigue syndrome
https://www.s4me.info/threads/mitoc...iral-fatigue-syndrome-1991-behan-et-al.36657/

 

Turns out they accomplished something else entirely.

 

Hi people. Some due context. We have crazy smart friends over in chemistry who make things like these cool and novel dyes. This paper is focused on one such dye. They wanted a demonstration of potential disease context applications and we had suspicions about LDs so we ran a small pilot sample of skin-derived fibroblasts in the study. So it's really more a chemistry paper than an ME/CFS paper, but I'm glad that we found some differences that can be followed up on.

I have been thinking about LDs and have some small pilot experiments going on the side to look at them in different tissues and this is part of that. We'll see if the rest of the work turns up anything useful.

 

there's also this thread that I saw years ago: https://www.s4me.info/threads/lipid...gated-in-me-should-they-be.17424/#post-296600

funnily enough one of the authors of the papers referenced in there sits a few meters from me and we are working together on the side experiments. small world.

 

Bhupesh Prusty posted this in reply to someone posting your paper. Thought it might interest you given your work immortalizing lymphocytes with EBV.

 

LDs are important in the innate immune response so differences in their dynamics in a pathogen context make sense.

If there are LD dynamics differences in pwME immune tissues/cells (for example) it could be one of two things happening:

1) an underlying difference in immune response leads to abnormal LD dynamics

OR

2) an underlying difference in LD dynamics leads to an abnormal immune response

A cause and effect problem to try and figure out as always.

 

Opportunism usually has a bad name but this is a type I like. Way to go!

 

I'm extremely excited by the WASF3 work by Hwang et al; so I can't help wondering about a possible link from their finding of endoplasmic reticulum stress to this finding of bigger lipid droplets.

Pharmacological ER stress promotes hepatic lipogenesis and lipid droplet formation
Jin-Sook Lee, Roberto Mendez, Henry H Heng, Zeng-Quan Yang, Kezhong Zhang

• PMID: 22347525
• PMCID: PMC3276380

Free PMC article
Abstract
Endoplasmic Reticulum (ER) stress refers to a condition of accumulation of unfolded or misfolded proteins in the ER lumen. A variety of biochemical stimuli or pathophysiologic conditions can directly or indirectly induce ER stress, leading to activation of an ER-originated adaptive signaling response called Unfolded Protein Response (UPR). Recent studies demonstrated that ER stress and UPR signaling are critically involved in the initiation and progression of many diseases, such as metabolic disease, cardiovascular disease, neurodegenerative disease, and cancer. In this study, we show that ER stress induced by pharmacologic reagents, including tunicamycin (TM) and thapsigargin (Tg), promotes hepatic lipogenesis and lipid droplet formation. Using quantitative gene expression analysis, we identified 3 groups of key lipogenic regulators or enzymes that are inducible by pharmacological ER stress in a human hepatoma cell line Huh-7. These ER stress-inducible lipogenic factors include: 1) lipogenic trans-activators including CCAAT/ enhancer binding protein alpha (C/EBPα), peroxisome proliferator-activated receptor gamma (PPARγ), PPARγ coacti-vator 1-alpha (PGC1α), and Liver X receptor alpha (LXRα); 2) components of lipid droplets including fat-specific protein 27 (FSP27), adipose differentiation related protein (ADRP), fat-inducing transcript 2 (FIT2), and adipocyte lipid-binding protein (AP2); 3) key enzymes involved in de novo lipogenesis including acetyl-CoA carboxylase 1 (ACC1) and stearoyl-CoA desaturase-1 (SCD1). Supporting the role of pharmacologic ER stress in up-regulating de novo lipogenesis, TM or Tg treatment significantly increased accumulation of cytosolic lipid droplet formation in the hepatocytes. Moreover, we showed that forced expression of an activated form of X-box binding protein 1 (XBP1), a potent UPR trans-activator, can dramatically increase expression of PPARγ and C/EBPα in Huh-7 cells. The identification of ER stress-inducible lipogenic regulators provides important insights into the molecular basis by which acute ER stress promotes de novo lipogenesis. In summary, the findings from this study have important implication in understanding the link between ER stress and metabolic disease.

 

@Murph maybe also have a look at the papers or summary quotes in these threads —

Lipid Biosynthesis Coordinates a Mitochondrial-to-Cytosolic Stress Response (2016, Cell)

and their follow-up preprint —

Unveiling the Intercompartmental Signaling Axis: Mitochondrial to ER Stress Response MERSR and its Impact on Proteostasis (2023, Preprint: BioRxiv)

 

ME Research UK:

As well as her ME Research UK-supported work on mitochondrial function in ME/CFS, Dr Sarah Annesley at La Trobe University has also been involved in a study measuring the characteristics of lipid droplets in fibroblasts from people with ME/CFS, and the results of that study were recently published in the journal Advanced Sensor Research. Read more:
https://www.meresearch.org.uk/do-lipid-droplets-play-a-role-in-me-cfs/