bioRxiv Science⌕ Search

bioRxiv · 10.1101/2025.04.15.648880

FGF8 promotes lipid droplet accumulation via the FGFR1/p-p38 axis in chondrocytes

Abstract

Chondrocytes store lipids in the form of lipid droplets (LDs) and maintain cartilage lipid metabolic homeostasis by consuming or regenerating LDs. This modulation is largely mediated by a series of biochemical factors. Fibroblast growth factor 8 (FGF8) is one of the most important factors involved in the proliferation, differentiation, and migration of chondrocytes, and has attracted increasing attention in the physiology and pathology of cartilage. However, the effect of FGF8 on LD accumulation in chondrocytes remains unclear. This study aimed to elucidate the role of FGF8 in LDs and explore the underlying biomechanism involved. The results showed that FGF8 promoted LD accumulation in chondrocytes by upregulating perilipin1 (Plin1) expression. FGF8 activates the cytoplasmic p-p38 signaling pathway via fibroblast growth factor receptor 1 (FGFR1) to increase LD accumulation in chondrocytes. Subsequent experiments with siRNAs and specific inhibitors further confirmed the importance of the FGFR1/p38 axis for LD accumulation in chondrocytes exposed to FGF8. These results increase our understanding of the role of FGF8 in the lipid metabolic homeostasis of chondrocytes and provide insights into the physiology and pathology of cartilage.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

huang, m., chen, h., wei, j., pi, c., duan, m., pu, x., niu, z., xu, s., tu, s., liu, s., li, j., zhang, l., liu, y., xu, c., xie, j.. 2025-04-16. FGF8 promotes lipid droplet accumulation via the FGFR1/p-p38 axis in chondrocytes. https://doi.org/10.1101/2025.04.15.648880

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

KEEP EXPLORING

Related preprints

A dynamic phosphoproteome reveals stage-specific regulation of cytokinesis in Leishmania

Leishmania parasites undergo extensive morphological and metabolic remodelling during their transition from motile insect promastigotes to non-motile intracellular amastigotes, yet how dynamic protein kinase signalling drives this process remains poorly understood. Here, we present a high-resolution temporal phosphoproteome of L. mexicana promastigote to axenic amastigote differentiation, profiling 16,495 phosphosites on 3,101 proteins across seven developmental time points and identifying 5,795 dynamically regulated sites. This temporal map reveals stage-specific signalling programs, including regulated sites in MPK2 and non-regulated sites in MRK1, protein kinases known to be essential for amastigote differentiation. Using analogue-sensitive (AS) chemical genetics, we show that acute inhibition of either kinase in axenic amastigotes disrupts the spatial coordination of cleavage furrow ingression with nuclear and kinetoplast segregation, revealing essential cytokinesis roles obscured in constitutive gene deletions. Despite generating similar cytokinesis phenotypes, genetic over-expression and cellular localisation analyses demonstrate that MPK2 and MRK1 act through spatially segregated signalling pathways. Time-resolved phosphoproteomics upon MPK2 inhibition places its activity upstream of cytoskeletal remodelling networks. Importantly, we show that the stage-specific requirement for MPK2 is defined by the parasite's morphology: while motile promastigotes tolerate MPK2 inhibition, genetic ablation of flagellar motility sensitises them to loss of MPK2 activity. Thus, flagellar motility acts as a mechanical buffer during promastigote division, explaining why non-motile amastigotes are vulnerable to MPK2 inhibition. Together, our findings provide a systems level framework for Leishmania signalling and demonstrate that cellular architecture and biomechanics dictate protein kinase dependency across developmental stages of the parasite.

cell biology↗

Single-cell Transcriptome-Proteome-PTMome(x8)-Metabolome (scTPPM) co-profiling decodes multimodal regulation during mouse oocyte meiosis

Single-cell multi-omics technology is crucial for comprehensive characterization of cellular molecular features. Despite recent advances in single-cell multi-omics approaches, co-profiling of nucleic acids, proteins, metabolites, and post-translational modifications (PTMs) within the same cell individuals remains major challenges. Here, we developed a single-cell transcriptome, proteome, PTMome, and metabolome (scTPPM) profiling approach, enabling simultaneous analysis of transcriptomes, proteomes, eight types of PTMs (e.g., phosphorylation, methylation, ubiquitination, O_GlcNAc, acetylation, crotonylation, lactylation, and succinylation), and metabolomes in individual cells. We demonstrated the scTPPM's performance in tumor cell lines and oocyte samples, reaching total identification and quantification of 27,668 genes, 4,847 proteins, 1,508 PTM sites, and 680 metabolites in single mouse oocytes. We profiled previously-uncharacterized dynamic crosstalk among the entire metabolic pathways from metabolic enzyme expression and regulation to metabolite-mediated post-translational modifications during oocyte maturation. In summary, scTPPM provided an effective workflow for multi-omics co-profiling in single cells, enabling multi-layered insights into complex regulatory network.

cell biology↗

Sequence context and partner availability specify divergent cell fates from a single transcription factor

Transcription factors drive the gene regulatory networks that control developmental transitions, yet which of their many targets a cell uses remains unresolved. Expressing Cebp, Cebp{beta} or Cebp{delta} identically, alone or with Oct4, Sox2, Klf4 and cMyc, gave four outcomes: adipocyte from fibroblasts and neural stem cells, trophectoderm from embryonic stem cells, and myeloid from B cells. Raising Cebp levels changed how many sites it reached, not which sequence it read: clustered motifs maintained somatic enhancers, while spillover onto low-copy sites created de novo enhancers carrying composites of Cebp and cell-type-restricted partners. In fibroblasts, Cebp also redistributed Oct4, Sox2 and Klf4 from early targets, blocking iPSC formation. Supplying the predicted partners rewrote the output: Spi1 redirected Cebp into parallel adipogenic and myeloid programs, via a transient PpargCD45 state using separate enhancers for each; TFAP2C abolished adipogenic conversion. Motif density and partner composites therefore assemble a factor's instructive output in the receiving cell.

cell biology↗