Macrophages (MAC) and polymorphonuclear granulocytes (PNG) are professional phagocytes which perform essential functions in antibacterial defense. The intracellular bacterium Mycobacterium tuberculosis persists and replicates in resting macrophages. Although it is generally assumed that activated MAC are central to protection against M. tuberculosis, PNG may also contribute to defense. We wondered whether PNG produce proinflammatory chemokines after stimulation by M. tuberculosis or its major cell wall component, lipoarabinomannan (LAM). In this study, we showed that M. tuberculosis- and LAM-activated human PNG secrete the leukocyte attractant interleukin-8 (IL-8) and the PNG-specific chemokine GRO-alpha in a dose-dependent manner. Treatment of PNG with the leukotriene-B4 inhibitor MK-886 prior to stimulation with M. tuberculosis or LAM partially blocked IL-8 and GRO-alpha induction, suggesting involvement of the 5-lipoxygenase pathway in the secretion of these chemokines. We conclude that PNG contribute to early resistance to M. tuberculosis via chemokine secretion.
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http://dx.doi.org/10.1128/iai.65.11.4620-4623.1997 | DOI Listing |
Clin Exp Med
January 2025
Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran.
Cellular senescence is understood to be a biological process that is defined as irreversible growth arrest and was originally recognized as a tumor-suppressive mechanism that prevents further propagation of damaged cells. More recently, cellular senescence has been shown to have a dual role in prevention and tumor promotion. Senescent cells carry a senescence-associated secretory phenotype (SASP), which is altered by secretory factors including pro-inflammatory cytokines, chemokines, and other proteases, leading to the alteration of the tissue microenvironment.
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January 2025
Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. Electronic address:
Besides its thermogenic capacity, brown adipose tissue (BAT) performs important secretory functions that regulate metabolism. However, the BAT microenvironment and factors involved in BAT homeostasis and adaptation to cold remain poorly characterized. We therefore aimed to study brown adipocyte-derived secreted factors that may be involved in adipocyte function and/or may orchestrate intercellular communications.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Southeast University, Nanjing 210096, China.
Heterogeneous roles of complement C3 have been implicated in tumor metastasis and are highly context dependent. However, the underlying mechanisms linking C3 to tumor metastasis remain elusive in renal cell carcinoma (RCC). Here, we demonstrate that C3 of RCC cell-derived extracellular vesicles (EVs) contributes to metastasis via polarizing tumor-associated macrophages (TAMs) into the immunosuppressive phenotype and recruiting polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs).
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January 2025
Department of Hepatobiliary Surgery, Jintan Affiliated Hospital of Jiangsu University, 213200, Changzhou, Jiangsu, China.
One of the outstanding features of chronic hepatitis B infection (CHB) is its strong association with liver fibrosis. CHB induced inflammation and injury trigger multiple biochemical and physical changes that include the promotion of a wide range of cytokines, chemokines and growth factors that activate hepatic stellate cells (HSCs) CHB induced activation of hepatic stellate cells (HSCs) is regarded as a central event in fibrogenesis to directly promote the synthesis of myofibroblasts and the expression of a range of materials to repair injured liver tissue. Fibrogenesis is modulated by the mainstream epigenetic machinery, as well as by non-coding RNA (ncRNA) that are often referred to as an ancillary epigenetic response to fine tune gene expression.
View Article and Find Full Text PDFZool Res
January 2025
Institute of Brain Science and Disease, School of Basic Medicine, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, Shandong 266071, China. E-mail:
Substantial evidence points to the early onset of peripheral inflammation in the development of Parkinson's disease (PD), supporting the "body-first" hypothesis. However, there remains a notable absence of PD-specific animal models induced by inflammatory cytokines. This study introduces a novel mouse model of PD driven by the proinflammatory cytokine CXCL1, identified in our previous research.
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