131 research outputs found

    CCL2 is transcriptionally controlled by the lysosomal protease cathepsin S in a CD74-dependent manner

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    Cathepsins S (CatS) has been implicated in numerous tumourigenic processes and here we document for the first time its involvement in CCL2 regulation within the tumour microenvironment. Analysis of syngeneic tumours highlighted reduced infiltrating macrophages in CatS depleted tumours. Interrogation of tumours and serum revealed genetic ablation of CatS leads to the depletion of several pro-inflammatory chemokines, most notably, CCL2. This observation was validated in vitro, where shRNA depletion of CatS resulted in reduced CCL2 expression. This regulation is transcriptionally mediated, as evident from RT-PCR analysis and CCL2 promoter studies. We revealed that CatS regulation of CCL2 is modulated through CD74 (also known as the invariant chain), a known substrate of CatS and a mediator of NFkB activity. Furthermore, CatS and CCL2 show a strong clinical correlation in brain, breast and colon tumours. In summary, these results highlight a novel mechanism by which CatS controls CCL2, which may present a useful pharmacodynamic marker for CatS inhibition

    The Role of Whey Acidic Protein Four-Disulfide-Core Proteins in Respiratory Health and Disease

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    Abstract Members of the whey acidic protein (WAP) or WAP four-disulfide-core (WFDC) family of proteins are a relatively under-explored family of low molecular weight proteins. The two most prominent WFDC proteins, secretory leukocyte protease inhibitor (SLPI) and elafin (or the precursor, trappin-2), have been shown to possess multiple functions including anti-protease, anti-bacterial, anti-viral and anti-inflammatory properties. It is therefore of no surprise that both SLPI and elafin/trappin-2 have been developed as potential therapeutics. Given the abundance of SLPI and elafin/trappin-2 in the human lung, most work in the area of WFDC research has focused on the role of WFDC proteins in protecting the lung from proteolytic attack. In this review, we will outline the current evidence regarding the expanding role of WFDC protein function with a focus on WFDC activity in lung disease as well as emerging data regarding the function of some of the more recently described WFDC proteins.</jats:p

    Sounding Situated Knowledges - Echo in Archaeoacoustics

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    This article proposes that feminist epistemologies via Donna Haraway's “Situated Knowledges” can be productively brought to bear upon theories of sonic knowledge production, as “sounding situated knowledges.” Sounding situated knowledges re-reads debates around the “nature of sound” with a Harawayan notion of the “natureculture of sound.” This aims to disrupt a traditional subject-object relation which I argue has perpetuated a pervasive “sonic naturalism” in sound studies. The emerging field of archaeoacoustics (acoustic archaeology), which examines the role of sound in human behaviour in archaeology, is theorized as an opening with potentially profound consequences for sonic knowledge production which are not currently being realized. The echo is conceived as a material-semiotic articulation, which akin to Haraway's infamous cyborg, serves as a feminist figuration which enables this renegotiation. Archaeoacoustics research, read following Haraway both reflectively and diffractively, is understood as a critical juncture for sound studies which exposes the necessity of both embodiedness and situatedness for sonic knowledge production. Given the potential opened up by archaeoacoustics through the figure of echo, a critical renegotiation of the subject-object relation in sound studies is suggested as central in further developing theories of sonic knowledge production

    IL4Rα signaling abrogates hypoxic neutrophil survival and limits acute lung injury responses <i>in vivo</i>

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    Rationale: Acute respiratory distress syndrome is defined by the presence of systemic hypoxia and consequent on disordered neutrophilic inflammation. Local mechanisms limiting the duration and magnitude of this neutrophilic response remain poorly understood.  Objectives: To test the hypothesis that during acute lung inflammation tissue production of proresolution type 2 cytokines (IL-4 and IL-13) dampens the proinflammatory effects of hypoxia through suppression of HIF-1a (hypoxia-inducible factor-1a)mediated neutrophil adaptation, resulting in resolution of lung injury.  Methods: Neutrophil activation of IL4Ra (IL-4 receptor a) signaling pathways was explored ex vivo in human acute respiratory distress syndrome patient samples, in vitro after the culture of human peripheral blood neutrophils with recombinant IL-4 under conditions of hypoxia, and in vivo through the study of IL4Ra-deficient neutrophils in competitive chimera models and wild-type mice treated with IL-4.  Measurements and Main Results: IL-4 was elevated in human BAL from patients with acute respiratory distress syndrome, and its receptor was identified on patient blood neutrophils. Treatment of human neutrophils with IL-4 suppressed HIF-1a-dependent hypoxic survival and limited proinflammatory transcriptional responses. Increased neutrophil apoptosis in hypoxia, also observed with IL-13, required active STAT signaling, and was dependent on expression of the oxygen-sensing prolyl hydroxylase PHD2. In vivo, IL-4Ra-deficient neutrophils had a survival advantage within a hypoxic inflamed niche; in contrast, inflamed lung treatment with IL-4 accelerated resolution through increased neutrophil apoptosis.  Conclusions: We describe an important interaction whereby IL4Ra-dependent type 2 cytokine signaling can directly inhibit hypoxic neutrophil survival in tissues and promote resolution of neutrophil-mediated acute lung injury
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