Biology subjects

Christopoulos, P.

Publications and source records attributed to Christopoulos, P..

4 recordsLinked to original sources

bioRxiv2025

Exercise induces anti-inflammatory reprogramming in macrophages via Hsp60

Physical activity exerts systemic anti-inflammatory effects and reduces the risk for multiple non-communicable diseases, with 7.2% of all-cause deaths globally being attributed to physical inactivity. However, the cellular and molecular components of the exercise-induced anti-inflammatory effects remain only partly understood. Herein we show that moderate-intensity exercise promotes anti-inflammatory reprograming of macrophages orchestrated by the skeletal muscle cells secretome. Primary bone marrow-derived macrophages (BMDMs) exposed to the secretome of mechanically-loaded myotubes (exercise-conditioned medium, exCM) acquire an anti-inflammatory transcriptional profile and increased reliance on oxidative phosphorylation, as shown by Seahorse real-time cell metabolic analysis, compatible with an M2-like phenotypic switch. Using an unbiased proteomic analysis of the exCM we identify the chaperonin Hsp60 as a key mediator of the anti-inflammatory effects of exercise. Hsp60 expression increases in mechanically loaded myotubes in vitro, in the quadriceps muscle and serum of mice following an 8-week program of moderate-intensity aerobic exercise, as well as in human muscle after resistance training. Importantly, treatment of BMDMs with Hsp60 in vitro recapitulates the exCM-induced transcriptional reprograming, promoting an M2-like phenotype. Taken together, our data highlight Hsp60 as a novel component of the skeletal muscle cell-macrophage crosstalk, providing mechanistic insights into the anti-inflammatory effects of exercise.

physiology↗

bioRxiv2023

Cancer-associated fibroblasts promote drug resistance in ALK-driven lung adenocarcinoma cells by upregulating lipid biosynthesis

Targeted therapy interventions using tyrosine kinase inhibitors (TKIs) provide encouraging treatment responses in ALK-rearranged lung adenocarcinomas, yet resistances occur almost inevitably. Apart from tumor cell-intrinsic resistance mechanisms, accumulating evidence supports a role of cancer-associated fibroblasts (CAFs) in affecting the therapeutic vulnerability of lung cancer cells. Here, we aimed to investigate underlying molecular networks shaping the therapeutic susceptibility of ALK-driven lung adenocarcinoma cells via tumor microenvironmental cues using three-dimensional (3D) spheroid co-culture settings. We show that CAFs promote therapy resistance of lung tumor cells against ALK inhibition by reducing apoptotic cell death and increasing cell proliferation. Using single-cell RNA-sequencing analysis, we show that genes involved in lipogenesis constitute the major transcriptional difference between TKI-treated homo- and heterotypic lung tumor spheroids. CAF-conditioned medium and CAF-secreted factors HGF and NRG1 were both able to promote resistance of 3D-cultured ALK-rearranged lung tumor cells via AKT signaling, which was accompanied by enhanced de novo lipogenesis and supression of lipid peroxidation. Notably, simultaneous targeting of ALK and SREBP-1 was able to overcome the established CAF-driven lipid metabolic-supportive niche of TKI-resistant lung tumor spheroids. Our findings highlight a crucial role of CAFs in mediating ALK-TKI resistance via lipid metabolic reprogramming and suggest new ways to overcome resistance towards molecular directed drugs by targeting vulnerabilities downstream of oncogenic signaling.

cancer biology↗

bioRxiv2023

Glycodelin acts as an immunomodulator in NSCLC and is a predictor of poor prognosis for patients receiving immunotherapy

Lung cancer has been shown to be targetable by novel immunotherapies which reactivate the immune system and enable tumor cell killing. However, treatment failure and resistance to these therapies is common. Consideration of sex as a factor influencing therapy resistance is still rare. We hypothesize that the success of the treatment is impaired by the presence of the immunosuppressive pregnancy-associated glycoprotein glycodelin that is expressed in patients with non-small-cell lung cancer (NSCLC). We demonstrate that the glycan pattern of NSCLC-derived glycodelin detected by a lectin-based enrichment assay highly resembles amniotic fluid-derived glycodelin A, which is known to have immunosuppressive properties. NSCLC-derived glycodelin interacts with immune cells in vitro and regulates the expression of genes associated with inflammatory and tumor microenvironment pathways. In tumor microarray samples of patients, high glycodelin staining in tumor areas results in an impaired overall survival of female patients. Moreover, glycodelin colocalizes to tumor infiltrating CD8+ T cells and pro-tumorigenic M2 macrophages. High serum concentrations of glycodelin prior to immunotherapy are associated with a poor progression-free survival (p < 0.001) of female patients receiving PD-(L)1 inhibitors. In summary, our findings suggest that glycodelin not only is a promising immunological biomarker for early identification of female patients that do not benefit from the costly immunotherapy, but also represents a promising immunotherapeutic target in NSCLC to improve therapeutic options in lung cancer. BackgroundImmunotherapy is one of the major achievements in the last decade of lung cancer treatment. However, resistance to treatment is common und not well understood. Glycodelin is an immunosuppressive protein well described during the establishment of a pregnancy. We investigated its influence on immune cells and patients receiving immunotherapy with a focus on the sex of the patients. Translational relevanceOur study examined that NSCLC-derived glycodelin shares similarities to amniotic fluid-derived glycodelin A and is predictive for a worse response to immunotherapy in female patients. Therefore, glycodelin might be a key player influencing a sex-specific response to immunotherapy in lung cancer.

cancer biology↗

bioRxiv2020

Polysaccharides from the fungus Inonotus obliquus activate macrophages into a tumoricidal phenotype via interaction with TLR2, TLR4 and Dectin-1a

BackgroundTumor-associated macrophages (TAMs) may both promote and suppress tumor development. Therefore, molecules that are able to activate and repolarize these cells into a tumoricidal phenotype could be of great interest as a new strategy for cancer immunotherapy. Fungal {beta}-glucans have been suggested as a promising way of activating TAMs, but most of the research has been carried out on particulate {beta}-glucans of large sizes (> 500 kDa), which potentially have different biological properties than smaller, water-soluble molecules with similar structures. MethodsBone marrow-derived mouse macrophages were treated with 6 different purified polysaccharides isolated from the medicinal fungus Inonotus obliquus. Nitric oxide concentration was quantified using the Griess assay and by qPCR of iNOS mRNA. IL-6 and TNF- concentrations were quantified using Luminex ELISA technology (using human monocyte-derived macrophages and mouse bone-marrow derived macrophages). Growth inhibition of cancer cells was measured using radiolabeled thymidine. Receptor interaction was determined using HEK-Blue reporter cell lines and TLR4 KO macrophages. Main findingsThe acidic, water-soluble polysaccharides AcF1, AcF2 and AcF3 induced nitric oxide (NO) production by mouse macrophages when combined with IFN-{gamma}, leading to a strong subsequent tumoricidal activity by the macrophages. Tumoricidal activity of AcF1 and AcF3 was fully retained in TLR4 knockout macrophages, demonstrating that the macrophage activation was not dependent on TLR4. Further, AcF3 induced high levels of the pro-inflammatory cytokines IL-6 and TNF- in human and mouse macrophages, independent of co-activation with IFN-{gamma}. The polysaccharides were shown to bind TLR2, TLR4 and Dectin-1a to varying degrees, and these receptors were likely to be responsible for the macrophage activation. The acidic polysaccharides AcF1, AcF2 and AcF3 strongly activated TLR2, while AcF3 and AcF1 activated TLR4. The acidic polysaccharides had low affinity to Dectin-1a compared to the polysaccharides IWN, EWN and A1, which suggests that this receptor is not the main receptor for the pro-inflammatory activity observed. ConclusionFor the first time, this study demonstrates that I. obliquus polysaccharides are able to bind multiple pattern recognition receptors to activate macrophages into a pro-inflammatory anti-tumor phenotype. The induction of tumoricidal activity in the macrophages as well as the interaction with TLR2, TLR4 and Dectin-1a suggest that the I. obliquus polysaccharides may have unique ways of interacting with macrophages, which could open up for new treatment options in cancer immunotherapy.

immunology↗