Biology subjects

De Marchis, F.

Publications and source records attributed to De Marchis, F..

3 recordsLinked to original sources

bioRxiv2023

The acidic intrinsically disordered region of the inflammatory mediator HMGB1 mediates fuzzy interactions with chemokine CXCL12

Chemokines engage in heterodimeric interactions to activate or dampen their cognate receptors in inflammatory conditions. The chemokine CXCL12 forms with the alarmin HMGB1 a patho-physiologically relevant heterocomplex (HMGB1[bullet]CXCL12), whose formation synergically promotes the inflammatory response elicited by the G-protein coupled receptor CXCR4. However, the molecular details of complex formation were still elusive. Through an integrative structural approach (NMR, AUC, ITC, MST, SAXS) we show that HMGB1[bullet]CXCL12 represents the first fuzzy chemokines heterocomplex reported so far. HMGB1 and CXCL12 form a dynamic equimolar assembly, rather than involving one HMGB1 and two CXCL12 molecules as previously assumed, with structured and unstructured HMGB1 regions recognizing the dimerization surface of CXCL12. We uncover an unexpected role of the acidic intrinsically disordered region (IDR) in heterocomplex formation and provide the first evidence that the acidic IDR facilitates the ternary HMGB1*CXCL12*CXCR4 interaction on the cell surface. Thus, the interaction of HMGB1 with CXCL12 diverges radically from the classical rigid heterophilic chemokine-chemokine dimerization. Simultaneous interference with the multiple interactions within HMGB1[bullet]CXCL12 complex formation might offer novel pharmacological strategies to inhibit its detrimental activity in inflammatory conditions.

biochemistry↗

bioRxiv2020

Discovery of 5,5'-methylenedi-2,3-cresotic acid as a potent inhibitor of the HMGB1/CXCL12 heterocomplex using Virtual Screening and NMR validation

HMGB1 is a key molecule that both triggers and sustains inflammation following infection or injury, and is involved in a large number of pathologies, including cancer. HMGB1 participates to the recruitment of inflammatory cells forming a heterocomplex with the chemokine CXCL12 (HMGB1*CXCL12), herewith activating the G-protein coupled receptor CXCR4. Thus, identification of molecules that disrupt this heterocomplex can offer novel pharmacological opportunities to treat inflammation related diseases. To identify new HMGB1*CXCL12 inhibitors we have performed a study on the ligandability of the single HMG boxes of HMGB1 followed by a virtual screening campaign on both HMG boxes using Zbc Drugs and three different docking programs (Glide, AutoDock Vina, AutoDock 4.2.6). The best poses in terms of scoring functions, visual inspection and predicted ADME properties were further filtered according to a pharmacophore model based on known HMGB1 binders and clustered according to their structures. Eight compounds representative of the clusters were tested for HMGB1 binding by NMR. We identified 5,5-methylenedi-2,3-cresotic acid (2a) as binder of both HMGB1 and CXCL12; 2a also targets the HMGB1*CXCL12 heterocomplex. In cell migration assays 2a inhibited the chemotactic activity of HMGB1*CXCL12 with IC50 in the subnanomolar range, the best documented up to now. These results pave the way for future structure activity relationship studies to optimize the pharmacological targeting of HMGB1*CXCL12 for anti-inflammatory purposes.

biochemistry↗

bioRxiv2019

Diflunisal targets the HMGB1/CXCL12 heterocomplex and blocks immune cell recruitment

Extracellular HMGB1 triggers inflammation following infection or injury, and supports tumorigenesis in inflammation-related malignancies. HMGB1 has several redox states: reduced HMGB1 recruits inflammatory cells to injured tissues forming a heterocomplex with CXCL12 and signaling via its receptor CXCR4; disulfide-containing HMGB1 binds to TLR4 and promotes inflammatory responses. Here we show that Diflunisal, an aspirin-like nonsteroidal anti-inflammatory drug (NSAID) that has been in clinical use for decades, specifically inhibits in vitro and in vivo the chemotactic activity of HMGB1 at nanomolar concentrations, at least in part by binding directly to both HMGB1 and CXCL12 and disrupting their heterocomplex. Importantly, Diflunisal does not inhibit TLR4-dependent responses. Our findings clarify the mode of action of Diflunisal, and open the way to the rational design of functionally specific anti-inflammatory drugs.

biochemistry↗