Enhancement by iron of interleukin 1 induced granulocyte macrophage colony stimulating factor (GM-CSF) production by human synovial fibroblasts

Study on the effect of deer bone in improving rheumatoid arthritis based on the "drug-target-pathway" association network

ETHNOPHARMACOLOGICAL RELEVANCE

Deer bone is rich in proteins, free amino acids, chondroitin, organic calcium, phosphorus ions, and other active components. Deer bone had been used widely in antiquity and were first compiled in renowned ancient masterpiece 'Mingyi Bielu ()' written by Hongjing Tao. The deer bone is recorded as non-toxic and has the effects of replenishing bones, strengthening sinews, expelling wind-dampness from the body, promoting muscle growth, and healing wounds. Modern pharmacological research suggests that deer bone can help promote bone density and enhance bone strength, making it potentially valuable for the prevention and treatment of diseases such as rheumatoid arthritis and osteoporosis. However, current studies on the component analysis and pharmacological effects of deer bone against rheumatoid arthritis (RA) are incomplete, which to some extent hinders the development and clinical application of deer bone drugs.

AIM OF THE STUDY

The components of deer bone were elucidated by label-free proteomics, and the drug-target-pathway association network was established by network pharmacology. The in vitro validation of the pathway provides a theoretical basis for deer bone as a potential therapeutic drug for rheumatoid arthritis, and also lays a solid foundation for the subsequent clinical application of the in vitro experiments established through serum pharmacology.

MATERIALS AND METHODS

We performed extraction of deer bone using traditional water extraction methods and employed label-free proteomics technology to identify and conduct bioinformatics analysis on the proteins and peptides in the deer bone hot water extract (DBHE). These components were considered potential drug targets, and we constructed a "drug-target-pathway" association network. Analysis revealed that the HIF-1 signaling pathway may be pivotal in DBWE's effect on RA. Hypoxia influences the occurrence and development of ferroptosis through various mechanisms. Therefore, we hypothesized that DBWE might induce ferroptosis, promoting apoptosis in RA-FLS under hypoxic conditions, thereby alleviating RA. Therefore, we performed flow cytometry, ELISA, immunofluorescence, RT-qPCR, and western blotting based on molecular docking. Considering the overall effect of drug metabolism post-ingestion, we used serum pharmacology to prepare serum for cellular administration.

RESULTS

It showed that DBWE reduces inflammation and synovial proliferation by inhibiting HO-1, increasing ROS production, upregulating ACSL4 expression and inducing RA-FLS apoptosis in hypoxic conditions. This study reveals the potential mechanism by which DBWE modulates ferroptosis to attenuate synovial proliferation in a hypoxic microenvironment and improve RA.

CONCLUSION

These findings not only provide a theoretical basis for deer bone as a potential therapeutic agent for RA, but also lay a solid foundation for subsequent clinical application through in vitro experiments established by serum pharmacology.

Granulocyte-macrophage colony stimulating factor is anabolic and interleukin-1beta is catabolic for rat articular chondrocytes

OBJECTIVE

To study the effects of GM-CSF and IL-1beta, both implicated in tissue damage in arthritis, on articular chondrocyte proliferation and metabolism, and to explore their agonist/antagonist effects.

METHODS

Chondrocytes were obtained from 1-month-old rats. First-passage monolayers were incubated for 24 h with or without GM-CSF and/or IL-1beta, and labeled with 3H-thymidine, 35S-SO4 and 14C-proline. Proteoglycan and collagen synthesis were analyzed by liquid chromatography and SDS-PAGE. Gene expression was measured by RT-PCR.

RESULTS

IL-1beta exerts potent, and GM-CSF weak, inhibitory effects on DNA synthesis. GM-CSF strongly stimulates, and IL-1beta inhibits, proteoglycan and collagen synthesis. IL-1beta suppresses the effect of GM-CSF, and increases the release of radioactive molecules from pre-labeled cartilage fragments; GM-CSF decreases the IL-1beta-induced effect. Interestingly, both cytokines induce the expression of each other's gene.

CONCLUSIONS

IL-1beta appears to be a catabolic and anti-anabolic agent for chondrocytes, whereas GM-CSF is mainly anabolic, and blocks the IL-1beta-induced catabolic effect. It is postulated that both agents are implicated in inflammation: IL-1beta promotes tissue catabolism and destruction, whereas GM-CSF enhances tissue reconstruction.

Intravenous iron therapy: well-tolerated, yet not harmless

In the majority of patients with chronic renal failure, it is essential to substitute erythropoietic agents and iron to maintain a haemoglobin level above 11 g dL-1. Intravenous iron is more effective than oral iron. Substitution of intravenous iron is mainly performed using iron(III)-hydroxide-sucrose complex (iron sucrose) and iron(III)-sodium-gluconate in sucrose (iron gluconate), and is, in general, well-tolerated. Nonetheless, intravenous iron therapy has effects on endothelial cells, polymorphonuclear leucocytes and cytokines which are most likely related to non-transferrin bound labile iron. These effects suggest a role of iron in infection or atherosclerosis. Yet, not all available data support the association of iron with infection and atherosclerosis. A recent trial showed that iron sucrose is safe when given as treatment for iron deficiency or for maintenance of iron stores. Nevertheless, iron therapy should be handled with caution but its use should not be feared whenever indicated.

Suppressive Effect of Iron on Concanavalin A‐Induced Multinucleated Giant Cell Formation by Human Monocytes

Immune dysfunction in patients with iron overload has been reported. Iron disturbed CD2 expression on T-cells, cell-mediated immunity by Th1 cells and monocyte functions including phagocytosis and natural killer activity. In the present study, we examined the effects of iron and desferrioxamine (DFX, an iron chelator) on generation of multinucleated giant cells (MGC) by human monocytes in vitro. Human monocytes were isolated from venous blood and cultured with concanavalin A (Con A) stimulation with additives, ferric citrate (Fe-citrate) or sodium citrate (Na-citrate) or DFX for 4 days. The cells were fixed and subjected to Wright staining. MGC formation was observed under light microscopy. Con A induced MGC formation in a dose-dependent manner, and reached a plateau after 3 days of incubation. MGC formation was suppressed when Con A-stimulated monocytes were cultured with the co-addition of Fe-citrate but not Na-citrate only in the early phase of culture (less than 24 hours). DFX also suppressed MGC formation in a dose-dependent manner. Using flow cytometry analysis, the co-addition of Fe-citrate significantly suppressed CD18 (beta2 integrin) and CD54 (ICAM-I) but not CD11a (alpha integrin) expression on Con A-stimulated monocytes. Iron supressed the generation of MGC by human monocytes in vitro. These observations suggested that iron might affect MGC generation by down-regulation of adhesion molecule expression on monocytes.