Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2023.11.06.565836

Advance Glycation End-products induction accelerate amyloid deposits in adipocyte`s lipid droplets

Izgilov, R.·Kislev, N.·Omari, E.·Benayahu, D.
View original source ↗Export metadata ↓

Abstract

Adipose tissue dysfunction is central to insulin resistance, and the emergence of type 2 diabetes (T2D) is associated with elevated levels of carbonyl metabolites from glucose metabolism. In this study, using methylglyoxal (MGO) and glycolaldehyde (GAD) carbonyl metabolites, induced protein glycation leading to misfolding and {beta}-sheet formation and generation of advanced glycation end products (AGEs). The formed AGEs compromise adipocytes activity. Microscopic and spectroscopic assays were used to examine the impact of MGO and GAD on lipid droplet - associated proteins. The results provide information about how glycation leads to the appearance of amyloidogenic proteins formation that hinders metabolism and autophagy in adipocytes. We measured the beneficial effects of metformin, an anti-diabetic drug, on misfolded protein as assessed by thioflavin (ThT) spectroscopy and improved autophagy. In vitro findings were complemented by in vivo analysis of white adipose tissue (WAT), where lipid droplet-associated {beta}-amyloid deposits were predominantly linked to adipose triglyceride lipase (ATGL), a lipid droplet protein. Bioinformatics, imaging, and biochemical methods affirm ATGLs role in {beta}-sheet secondary structure creation. Our results highlighted the pronounced presence of amyloidogenic proteins in adipocytes treated with carbonyl compounds, potentially reshaping our understanding of adipocyte pathology in the context of T2D. This in-depth exploration offers novel perspectives on related pathophysiology and underscores the potential of adipocytes as pivotal therapeutic targets, bridging T2D, amyloidosis, protein glycation, and adipocyte malfunction. Significance StatementThe generation of advanced glycation end products (AGEs) has a strong connection to diabetes severity . Adipose tissue is known to play a key role in the metabolic impairment and obesity associated with diabetes. We used the carbonyl compounds methylglyoxal (MGO) and glycolaldehyde (GAD) to create AGEs in adipocytes. The results of this study indicate that glycation not only affects cell metabolism and impairs adipocyte lipolysis, but also alters autophagy and increases protein amyloid deposits related to the membrane of lipid droplets. We identify the ATGL as a protein prone to {beta} sheet alteration. consequently, ATGL emerges as a pivotal actor in lipid droplet metabolism and a prospective therapeutic target for T2D complications.

Explore related subjects

cell biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Izgilov, R., Kislev, N., Omari, E., Benayahu, D.. 2023-11-07. Advance Glycation End-products induction accelerate amyloid deposits in adipocyte`s lipid droplets. https://doi.org/10.1101/2023.11.06.565836

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Functional characterization of Rho GTPase activating proteins SYDE1 and SYDE2

The human genome encodes more than 60 proteins containing Rho GTPase activating protein (RhoGAP) domains, many of which remain understudied with respect to their target specificity and biological roles. SYDE1 and SYDE2 are two such orphan RhoGAPs, for which there are few studies characterizing their biochemical and cellular functions and conflicting reports identifying their cognate GTPases. We previously identified SYDE1 and SYDE2 in a screen for substrates of the c-Jun N-terminal kinases. Here, we show that SYDE1 and SYDE2 are preferentially phosphorylated by JNK1 relative to other mitogen-activated protein kinases (MAPKs) at sites proximal to a kinase docking region. Purified SYDE1 and SYDE2 are shown to have significant catalytic GAP activity toward RhoA, Rac1, and Cdc42. However, neither up- nor down-regulation of SYDE1/2 expression leads to detectable changes in bulk GTP loading of any of these GTPases. Nevertheless, we demonstrate that SYDE1 and SYDE2, in a partially GAP-dependent manner, increase cell spreading and number of focal adhesions, and promote more directionally persistent migration in HEK293 cells. Together, these findings establish SYDE1 and SYDE2 as robust JNK substrates with catalytic activity toward a set of Rho GTPases and reveal basic functions of SYDE1 and SYDE2 in regulating cell morphology, adhesion, and migration.

cell biology↗
bioRxiv2026

The filopodial scaffold polyphosphate dictates cell adhesion-versus-invasion decisions

Inorganic polyphosphate (polyP) is an ancient polymer conserved across all life, serving cell type and location specific functions in every major compartment. Yet its role at the plasma membrane, where it accumulates to peak levels in many primary cells, is largely unknown. Here we identify polyP as a stabilizing component of filopodia, actin based membrane protrusions that govern cell adhesion, contact inhibition, and chemotaxis. Elevating cellular polyP increases filopodial stability and enhances cell adhesion, whereas reducing polyP accelerates filopodial disassembly and promotes cell migration. Mechanistically, we find that polyP acts as a structural filopodial scaffold, recruiting and organizing IRSp53, a membrane curvature inducing protein. We show that metastatic fibroblasts and breast cancer organoids carry markedly reduced and intracellularly reorganized polyP levels relative to their non transformed counterparts. Restoring endogenous polyP via lipid nanoparticle delivery suppresses their invasive phenotypes and reverses prometastatic gene expression signatures, implicating polyP as a primordial tumor suppressor.

cell biology↗
bioRxiv2026

Mitochondrial transfer mediates metabolic communication between beta cells and islet macrophages

Pancreatic islet macrophages support islet homeostasis and adapt their metabolic program in response to environmental cues, including beta cell released factors. Intercellular mitochondrial transfer is a biological process that modulates cellular responses. To test whether beta cells, which are strongly secretory, transfer mitochondria to islet macrophages, we generated mice with beta cell-specific expression of mitochondrial GFP (PhAMfloxIns1Cre). We demonstrate that beta cells transfer mitochondria to islet macrophages in vivo and in vitro. Diabetogenic stressors did not alter the frequency of mitochondrial transfer and macrophages containing beta cell-derived GFP exhibit increased protein synthesis rates. RNA-seq identified upregulation of activity-regulated cytoskeleton associated protein (Arc) in macrophages receiving beta cell-derived mitochondria, while disruption of actin cytoskeleton dynamics prevented mitochondrial transfer. Together, these findings identify mitochondrial transfer as a previously unrecognized mechanism of beta cell-macrophage communication that may contribute to islet homeostasis and immune regulation.

cell biology↗