Browsing by Subject "IL-1α"

Now showing 1 - 4 of 4
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    Determining distinct roles of IL-1α through generation of an IL-1α knockout mouse with no defect in IL-1β expression
    (Frontiers Media, 2022-11-24) Malireddi, R.K. Subbarao; Bynigeri, Ratnakar R.; Kancharana, Balabhaskararao; Sharma, Bhesh Raj; Burton, Amanda R.; Pelletier, Stephane; Kanneganti, Thirumala-Devi; Medical and Molecular Genetics, School of Medicine
    Interleukin 1α (IL-1α) and IL-1β are the founding members of the IL-1 cytokine family, and these innate immune inflammatory mediators are critically important in health and disease. Early studies on these molecules suggested that their expression was interdependent, with an initial genetic model of IL-1α depletion, the IL-1α KO mouse (Il1a-KOline1), showing reduced IL-1β expression. However, studies using this line in models of infection and inflammation resulted in contrasting observations. To overcome the limitations of this genetic model, we have generated and characterized a new line of IL-1α KO mice (Il1a-KOline2) using CRISPR-Cas9 technology. In contrast to cells from Il1a-KOline1, where IL-1β expression was drastically reduced, bone marrow-derived macrophages (BMDMs) from Il1a-KOline2 mice showed normal induction and activation of IL-1β. Additionally, Il1a-KOline2 BMDMs showed normal inflammasome activation and IL-1β expression in response to multiple innate immune triggers, including both pathogen-associated molecular patterns and pathogens. Moreover, using Il1a-KOline2 cells, we confirmed that IL-1α, independent of IL-1β, is critical for the expression of the neutrophil chemoattractant KC/CXCL1. Overall, we report the generation of a new line of IL-1α KO mice and confirm functions for IL-1α independent of IL-1β. Future studies on the unique functions of IL-1α and IL-1β using these mice will be critical to identify new roles for these molecules in health and disease and develop therapeutic strategies.
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    Ex vivo culture of mouse skin activates an interleukin 1 alpha-dependent inflammatory response
    (Wiley, 2020-01) Zhou, Hong-Ming; Slominski, Radomir M.; Seymour, Leroy J.; Bell, Maria C.; Dave, Priya; Atumonye, Joseph; Wright, William, III.; Dawes, Avery; Griesenauer, Brad; Paczesny, Sophie; Kaplan, Mark H.; Spandau, Dan F.; Turner, Matthew J.; Dermatology, School of Medicine
    Ex vivo culture of mouse and human skin causes an inflammatory response characterized by production of multiple cytokines. We used ex vivo culture of mouse tail skin specimens to investigate mechanisms of this skin culture-induced inflammatory response. Multiplex assays revealed production of interleukin 1 alpha (IL-1α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), chemokine C-X-C motif ligand 1 (CXCL1), granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) during skin culture, and quantitative PCR revealed transcripts for these proteins were also increased. Ex vivo cultures of skin from myeloid differentiation primary response 88 deficient mice (Myd88-/- ) demonstrated significantly reduced expression of transcripts for the aforementioned cytokines. The same result was observed with skin from interleukin 1 receptor type 1 deficient mice (Il1r1-/- ). These data suggested the IL-1R1/MyD88 axis is required for the skin culture-induced inflammatory response and led us to investigate the role of IL-1α and IL-1β (the ligands for IL-1R1) in this process. Addition of IL-1α neutralizing antibody to skin cultures significantly reduced expression of Cxcl1, Il6 and Csf3. IL-1β neutralization did not reduce levels of these transcripts. These studies suggest that IL-1α promotes the skin the culture-induced inflammatory response.
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    Interleukin-1α dependent survival of cardiac fibroblasts is associated with StAR/STARD1 expression and improved cardiac remodeling and function after myocardial infarction
    (Elsevier, 2021) Razin, Talya; Melamed-Book, Naomi; Argaman, Jasmin; Galin, Iris; Lowy, Yosef; Anuka, Eli; Naftali-Shani, Nili; Kandel-Kfir, Michal; Garfinkel, Benjamin P.; Brielle, Shlomi; Granot, Zvi; Apte, Ron N.; Conway, Simon J.; Molkentin, Jeffery D.; Kamari, Yehuda; Leor, Jonathan; Orly, Joseph; Pediatrics, School of Medicine
    Aims: One unaddressed aspect of healing after myocardial infarction (MI) is how non-myocyte cells that survived the ischemic injury, keep withstanding additional cellular damage by stress forms typically arising during the post-infarction inflammation. Here we aimed to determine if cell survival is conferred by expression of a mitochondrial protein novel to the cardiac proteome, known as steroidogenic acute regulatory protein, (StAR/STARD1). Further studies aimed to unravel the regulation and role of the non-steroidogenic cardiac StAR after MI. Methods and results: Following permanent ligation of the left anterior descending coronary artery in mouse heart, timeline western blot analyses showed that StAR expression corresponds to the inflammatory response to MI. Following the identification of StAR in mitochondria of cardiac fibroblasts in culture, confocal microscopy immunohistochemistry (IHC) identified StAR expression in left ventricular (LV) activated interstitial fibroblasts, adventitial fibroblasts and endothelial cells. Further work with the primary fibroblasts model revealed that interleukin-1α (IL-1α) signaling via NF-κB and p38 MAPK pathways efficiently upregulates the expression of the Star gene products. At the functional level, IL-1α primed fibroblasts were protected against apoptosis when exposed to cisplatin mimicry of in vivo apoptotic stress; yet, the protective impact of IL-1α was lost upon siRNA mediated StAR downregulation. At the physiological level, StAR expression was nullified during post-MI inflammation in a mouse model with global IL-1α deficiency, concomitantly resulting in a 4-fold elevation of apoptotic fibroblasts. Serial echocardiography and IHC studies of mice examined 24 days after MI revealed aggravation of LV dysfunction, LV dilatation, anterior wall thinning and adverse tissue remodeling when compared with loxP control hearts. Conclusions: This study calls attention to overlooked aspects of cellular responses evolved under the stress conditions associated with the default inflammatory response to MI. Our observations suggest that LV IL-1α is cardioprotective, and at least one mechanism of this action is mediated by induction of StAR expression in border zone fibroblasts, which renders them apoptosis resistant. This acquired survival feature also has long-term ramifications on the heart recovery by diminishing adverse remodeling and improving the heart function after MI.
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    NF-κB activation and interleukin 6 production in fibroblasts by estrogen receptor-negative breast cancer cell-derived interleukin 1α
    (National Academy of Sciences, 1998-06-09) Bhat-Nakshatri, Poornima; Newton, Thomas R.; Goulet, Robert; Nakshatri, Harikrishna
    Several angiogenic factors and extracellular matrix-degrading enzymes that promote invasion and metastasis of cancer are produced by stromal fibroblasts that surround cancer cells. The expression of genes that code for some of these proteins is regulated by the transcription factor NF-κB. In this report, we demonstrate that conditioned medium (CM) from estrogen receptor (ER)-negative but not ER-positive breast cancer cells induces NF-κB in fibroblasts. In contrast, CM from both ER-positive and ER-negative breast cancer cells induces NF-κB in macrophages and endothelial cells. NF-κB activation in fibroblasts was accompanied by induction of interleukin 6 (IL-6) and urokinase plasminogen activator (uPA), both of which promote angiogenesis and metastasis. A survey of cytokines known for their ability to induce NF-κB identified IL-1α as the factor responsible for NF-κB activation in fibroblasts. Analysis of primary breast carcinomas revealed the presence of IL-1α transcripts in majority of lymph node-positive breast cancers. These results along with the known role of IL-1α and IL-6 in osteoclast formation provide insight into the mechanism of metastasis and hypercalcemia in advanced breast cancers.