STAT1‐ and NFAT‐independent amplification of purinoceptor function integrates cellular senescence with interleukin‐6 production in preadipocytes
Background and Purpose
Senescent preadipocytes promote adipose tissue dysfunction by secreting pro‐inflammatory factors, although little is known about the mechanisms regulating their production. We investigated if up‐regulated purinoceptor function sensitizes senescent preadipocytes to cognate agonists and how such sensitization regulates inflammation.
Experimental Approach
Etoposide was used to trigger senescence in 3T3‐L1 preadipocytes. CRISPR/Cas9 technology or pharmacology allowed studies of transcription factor function. Fura‐2 imaging was used for calcium measurements. Interleukin‐6 levels were quantified using quantitative PCR and ELISA. Specific agonists and antagonists supported studies of purinoceptor coupling to interleukin‐6 production. Experiments in MS1 VEGF angiosarcoma cells and adipose tissue samples from obese mice complemented preadipocyte experiments.
Key Results
DNA damage‐induced senescence up‐regulated purinoceptor expression levels in preadipocytes and MS1 VEGF angiosarcoma cells. ATP‐evoked Ca2+ release was potentiated in senescent preadipocytes. ATP enhanced interleukin‐6 production, an effect mimicked by ADP but not UTP, in a calcium‐independent manner. Senescence‐associated up‐regulation and activation of the adenosine A3 receptor also enhanced interleukin‐6 production. However, nucleotide hydrolysis was not essential because exposure to ATPγS also enhanced interleukin‐6 secretion. Pharmacological experiments suggested coupling of P2X ion channels and P2Y12–P2Y13 receptors to downstream interleukin‐6 production. Interleukin‐6 signalling exacerbated inflammation during senescence and compromised adipogenesis.
Conclusions and Implications
We report a previously uncharacterized link between cellular senescence and purinergic signalling in preadipocytes and endothelial cancer cells, raising the possibility that up‐regulated purinoceptors play key modulatory roles in senescence‐associated conditions like obesity and cancer. There is potential for exploitation of specific purinoceptor antagonists as therapeutics in inflammatory disorders.
Other Information
Published in: British Journal of Pharmacology
License: http://creativecommons.org/licenses/by/4.0/
See article on publisher's website: https://dx.doi.org/10.1111/bph.15978
Funding
Qatar National Research Fund (GSRA4‐1‐0330‐17010), PhD-Molecular Mechanisms of Cellular Senescence.
Qatar National Research Fund (NPRP10‐1205‐160010), Investigating Molecular Mechanisms of Common Inflammatory Pathways in Obesity and Diabetes.
Qatar National Research Fund (UREP25‐026‐3‐005), Role of the endoplasmic reticulum (ER) protein TMEM38B in promoting senescence, inflammation and adipose dysfunction in obesity.
Weill Cornell Medicine - Qatar (SRMP 003‐01).
Open Access funding provided by the Qatar National Library.
History
Language
- English
Publisher
WileyPublication Year
- 2022
License statement
This Item is licensed under the Creative Commons Attribution 4.0 International License.Institution affiliated with
- Weill Cornell Medicine - Qatar
- Hamad Bin Khalifa University
- College of Health and Life Sciences - HBKU