IκBζ facilitates protective immunity against Salmonella infection via Th1 differentiation and IgG production

LINC01686 affects LPS-induced cytokine expression via the miR-18a-5p/A20/STAT1 axis in THP-1 cells

BACKGROUND AND OBJECTIVE

Long noncoding RNAs (lncRNAs) are crucial in regulating various physiological and pathological processes, including immune responses. LINC01686 is a lncRNA with previously uncharacterized functions in immune regulation. This study aims to investigate the function of LINC01686 in lipopolysaccharide (LPS)-induced inflammatory responses in the human monocytic leukemia cell line THP-1 and its potential regulatory mechanisms involving miR-18a-5p and the anti-inflammatory protein A20.

METHOD

THP-1 cells were stimulated with LPS to induce inflammatory responses, followed by analysis of LINC01686 expression levels. The role of LINC01686 in regulating the expression of interleukin (IL)-6, IL-8, A20, and signal transducer and activator of transcription 1 (STAT1) was examined using small interfering RNA-mediated knockdown. Additionally, the involvement of miR-18a-5p in LINC01686-mediated regulatory pathways was assessed by transfection with decoy RNAs mimicking the miR-18a-5p binding sites of LINC01686 or A20 messenger RNA.

RESULTS

LINC01686 expression was upregulated in THP-1 cells following LPS stimulation. Suppression of LINC01686 enhanced LPS-induced expression of IL-6 and IL-8, mediated through increased production of reactive oxygen species. Moreover, LINC01686 knockdown upregulated the expression and activation of IκB-ζ, STAT1, and downregulated A20 expression. Transfection with decoy RNAs reversed the effects of LINC01686 suppression on A20, STAT1, IL-6, and IL-8 expression, highlighting the role of LINC01686 in sponging miR-18a-5p and regulating A20 expression.

CONCLUSION

This study provides the first evidence that LINC01686 plays a critical role in modulating LPS-induced inflammatory responses in THP-1 cells by sponging miR-18a-5p, thereby regulating the expression and activation of A20 and STAT1. These findings shed light on the complex regulatory mechanisms involving lncRNAs in immune responses and offer potential therapeutic targets for inflammatory diseases.

Regulation of IkappaB Protein Expression by Early Gestation in the Thymus of Ewes

The thymus is an essential component of maternal immune systems that play key roles in recognizing the placenta as immunologically foreign. The inhibitor of the NF-κB (IκB) family has essential effects on the NF-κB pathway; however, it is unclear whether early pregnancy modulates the expression of the IκB family in the thymus. In this study, maternal thymuses were sampled on day 16 of nonpregnancy and different gestation stages in the ovine, and the expression of IκB proteins was analyzed. The data showed that B cell leukemia-3 and IκBβ increased; however, IκBα, IκBε, and IKKγ deceased during gestation. Furthermore, there was an increase in IκBNS and IκBζ expression values on day 13 of pregnancy; however, this decreased on day 25 of gestation. In summary, the expression of the IκB family was modulated in the thymus during early gestation, suggesting that the maternal thymus can be associated with maternal immunologic tolerance and pregnancy establishment in ewes.

The central inflammatory regulator IκBζ: induction, regulation and physiological functions

IκBζ (encoded by NFKBIZ) is the most recently identified IkappaB family protein. As an atypical member of the IkappaB protein family, NFKBIZ has been the focus of recent studies because of its role in inflammation. Specifically, it is a key gene in the regulation of a variety of inflammatory factors in the NF-KB pathway, thereby affecting the progression of related diseases. In recent years, investigations into NFKBIZ have led to greater understanding of this gene. In this review, we summarize the induction of NFKBIZ and then elucidate its transcription, translation, molecular mechanism and physiological function. Finally, the roles played by NFKBIZ in psoriasis, cancer, kidney injury, autoimmune diseases and other diseases are described. NFKBIZ functions are universal and bidirectional, and therefore, this gene may exert a great influence on the regulation of inflammation and inflammation-related diseases.

Spatially resolved deconvolution of the fibrotic niche in lung fibrosis

A defining pathological feature of human lung fibrosis is localized tissue heterogeneity, which challenges the interpretation of transcriptomic studies that typically lose spatial information. Here we investigate spatial gene expression in diagnostic tissue using digital profiling technology. We identify distinct, region-specific gene expression signatures as well as shared gene signatures. By integration with single-cell data, we spatially map the cellular composition within and distant from the fibrotic niche, demonstrating discrete changes in homeostatic and pathologic cell populations even in morphologically preserved lung, while through ligand-receptor analysis, we investigate cellular cross-talk within the fibrotic niche. We confirm findings through bioinformatic, tissue, and in vitro analyses, identifying that loss of NFKB inhibitor zeta in alveolar epithelial cells dysregulates the TGFβ/IL-6 signaling axis, which may impair homeostatic responses to environmental stress. Thus, spatially resolved deconvolution advances understanding of cell composition and microenvironment in human lung fibrogenesis.

IκBζ controls NLRP3 inflammasome activation via upregulation of the Nlrp3 gene

Inflammasome activation induces the maturation and secretion of interleukin (IL)-1β and -18, and is dependent on NF-κB signaling to induce the transcription of the inflammasome components, called the priming step. This study elucidated the role of IκBζ, an atypical IκBs (inhibitor of κB) and a coactivator of NF-κB target genes, on the activation of inflammasome. Bone marrow-derived macrophages (BMDMs) that originated from IκBζ-encoding Nfkbiz gene depletion mice presented a defect in NLRP3 inflammasome activation. In addition, the Nfkbiz^+/- and Nfkbiz^-/- mice significantly attenuated serum IL-1β secretion in response to a monosodium urate injection, a NLRP3 trigger, when compared with Nfkbiz^-+/+ mice. The lack of IκBζ in BMDMs produced a disability in the expression of Nlrp3 and pro-Il1β mRNAs during the priming step. In addition, ectopic IκBζ expression enhanced the Nlrp3 promoter activity, and Nlrp3 and pro-Il1β transcription. Overall, IκBζ controlled the activation of NLRP3 inflammasome by upregulating the Nlrp3 gene during the priming step.