Effects of SOCS1-overexpressing dendritic cells on Th17- and Treg-related cytokines in COPD mice

Curcumin alleviated dextran sulfate sodium-induced colitis by recovering memory Th/Tfh subset balance

BACKGROUND

Restoration of immune homeostasis by targeting the balance between memory T helper (mTh) cells and memory follicular T helper (mTfh) cells is a potential therapeutic strategy against ulcerative colitis (UC). Because of its anti-inflammatory and immunomodulatory properties, curcumin (Cur) is a promising drug for UC treatment. However, fewer studies have demonstrated whether Cur can modulate the mTh/mTfh subset balance in mice with colitis.

AIM

To explore the potential mechanism underlying Cur-mediated alleviation of colitis induced by dextran sulfate sodium (DSS) in mice by regulating the mTh and mTfh immune homeostasis.

METHODS

Balb/c mice were administered 3% and 2% DSS to establish the UC model and treated with Cur (200 mg/kg/d) by gavage on days 11-17. On the 18th d, all mice were anesthetized and euthanized, and the colonic length, colonic weight, and colonic weight index were evaluated. Histomorphological changes in the mouse colon were observed through hematoxylin-eosin staining. Levels of Th/mTh and Tfh/mTfh cell subsets in the spleen were detected through flow cytometry. Western blotting was performed to detect SOCS-1, SOCS-3, STAT3, p-STAT3, JAK1, p-JAK1, and NF-κB p65 protein expression levels in colon tissues.

RESULTS

Cur effectively mitigates DSS-induced colitis, facilitates the restoration of mouse weight and colonic length, and diminishes the colonic weight and colonic weight index. Simultaneously, it hinders ulcer development and inflammatory cell infiltration in the colonic mucous membrane. While the percentage of Th1, mTh1, Th7, mTh7, Th17, mTh17, Tfh1, mTfh1, Tfh7, mTfh7, Tfh17, and mTfh17 cells decreased after Cur treatment of the mice for 7 d, and the frequency of mTh10, Th10, mTfh10, and Tfh10 cells in the mouse spleen increased. Further studies revealed that Cur administration prominently decreased the SOCS-1, SOCS-3, STAT3, p-STAT3, JAK1, p-JAK1, and NF-κB p65 protein expression levels in the colon tissue.

CONCLUSION

Cur regulated the mTh/mTfh cell homeostasis to reduce DSS-induced colonic pathological damage, potentially by suppressing the JAK1/STAT3/SOCS signaling pathway.

Integrating RNA-seq and scRNA-seq to explore the mechanism of macrophage ferroptosis associated with COPD

Aims: Our study focused on whether macrophages ferroptosis is associated with the pathogenesis of chronic obstructive pulmonary disease (COPD) or not.

Main methods: We first identified macrophage module genes by weighted gene co-expression network analysis (WGCNA) in RNA sequencing (RNA-seq) date from COPD, and then identified macrophage marker genes by comprehensive analysis of single-cell RNA sequencing (scRNA-seq) data from COPD macrophages. There were 126 macrophage marker genes identified, and functional enrichment analyses indicated that ferroptosis pathway genes were significantly enriched. Secondly, we identified eight macrophage ferroptosis related genes and based on these eight genes, we performed co-expression analysis and drug prediction. Thirdly, two biomarkers (SOCS1 and HSPB1) were screened by the least absolute shrinkage and selection operator (LASSO), random forest (RF), and support vector machine-recursive feature elimination (SVM-RFE) and established an artificial neural network (ANN) for diagnosis. Subsequently, the biomarkers were validated in the dataset and validation set. These two biomarkers were then subjected to single gene-gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) analysis, and the ceRNA network was constructed. Finally, we carried out molecular validation with COPD models in vitro for cell counting kit-8 (CCK8) experiments, Western blot and quantitative real-time PCR (qRT-PCR) analysis and transmission electron microscopy (TEM).

Key findings: This study revealed the vital role of macrophage ferroptosis in COPD, and novel biomarkers (SOCS1 and HSPB1) may be involved in the pathogenesis of COPD by regulating macrophage ferroptosis.

Significance: Taken together, our results suggest that targeting SOCS1 and HSPB1 could treat COPD by inhibiting macrophage ferroptosis.

Ad-hoc modifications of cyclic mimetics of SOCS1 protein: Structural and functional insights

Suppressors of cytokine signaling 1 (SOCS1) protein, a negative regulator of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway, possesses a small kinase inhibitory region (KIR) involved in the inhibition of JAK kinases. Several studies showed that mimetics of KIR-SOCS1 can be potent therapeutics in several disorders (e.g., neurological, autoimmune or cardiovascular diseases). In this work, starting from a recently identified cyclic peptidomimetic of KIR-SOCS1, icPS5(Nal1), to optimize the peptide structure and improve its biological activity, we designed novel derivatives, containing crucial amino acids substitutions and/or modifications affecting the ring size. By combining microscale thermophoresis (MST), Circular Dichroism (CD), Nuclear Magnetic Resonance (NMR) and computational studies, we showed that the cycle size plays a key role in the interaction with JAK2 and the substitution of native residues with un-natural building blocks is a valid tool to maintain low-micromolar affinity toward JAK2, greatly increasing their serum stability. These findings contribute to increase the structural knowledge required for the recognition of SOCS1/JAK2 and to progress towards their conversion into more drug-like compounds.