Psoriasis is a chronic, inflammatory skin disease, frequently associated with dyslipidemia. Lipid disturbance in psoriasis affects both circulatory system and cutaneous tissue. Epidermal Langerhans cells (LCs) are tissue-resident DCs that maintain skin immune surveillance and mediate various cutaneous disorders, including psoriasis. However, the role of LCs in psoriasis development and their lipid metabolic alternation remains unclear. Here, we demonstrate that epidermal LCs of psoriasis patients enlarge with longer dendrites and possess elevated IL-23p19 mRNA and a higher level of neutral lipids when compared with normal LCs of healthy individuals. Accordantly, epidermal LCs from imiquimod-induced psoriasis-like dermatitis in mice display overmaturation, enhanced phagocytosis, and excessive secretion of IL-23. Remarkably, these altered immune properties in lesional LCs are tightly correlated with elevated neutral lipid levels. Moreover, the increased lipid content of psoriatic LCs might result from impaired autophagy of lipids. Bulk RNA-Seq analysis identifies dysregulated genes involved in lipid metabolism, autophagy, and immunofunctions in murine LCs. Overall, our data suggest that dysregulated lipid metabolism influences LC immunofunction, which contributes to the development of psoriasis, and therapeutic manipulation of this metabolic process might provide an effective measurement for psoriasis.
Xilin Zhang, Xiaorui Li, Yuanyuan Wang, Youdong Chen, Yijun Hu, Chunyuan Guo, Zengyang Yu, Peng Xu, Yangfeng Ding, Qing-Sheng Mi, Jianhua Wu, Jun Gu, Yuling Shi
α-1 antitrypsin (AAT) is a serine protease inhibitor that plays a pivotal role in maintaining lung homeostasis. The most common AAT allele associated with AAT deficiency (AATD) is PiZ. Z-AAT accumulates in cells due to misfolding, causing severe AATD. The major function of AAT is to neutralize neutrophil elastase in the lung. It is generally accepted that loss of antiprotease function is a major cause of COPD in individuals with AATD. However, it is now being recognized that the toxic gain-of-function effect of Z-AAT in macrophage likely contributes to lung disease. In the present study, we determined that TLR7 signaling is activated in Z-MDMs, and the expression level of NLRP3, one of the targets of TLR7 signaling, is significantly higher in Z- compared with M-MDMs. We also determined that the level of endosomal Alu RNA is significantly higher in Z-compared with M-MDMs. Alu RNA is a known endogenous ligand that activates TLR7 signaling. Z-AAT likely induces the expression of Alu elements in MDMs and accelerates monocyte death, leading to the higher level of endosomal Alu RNA in Z-MDMs. Taken together,this study identifies a mechanism responsible for the toxic gain of function of Z-AAT macrophages.
Jungnam Lee, Naweed Mohammad, Yuanqing Lu, Keunsoo Kang, Kyudong Han, Mark Brantly
Liver diseases have become a major comorbidity health concern in people living with HIV-1 (PLWH) under combination antiretroviral therapy (cART). To investigate if HIV-1 infection and cART interact to lead to liver diseases, humanized mice reconstituted with progenitor cells from human fetal livers were infected with HIV-1 and treated with cART. We report here that chronic HIV-1 infection with cART induced hepatitis and liver fibrosis in humanized mice, associated with accumulation of M2-like macrophages (M2LM), elevated TGFβ and interferon signaling in the liver. Interestingly, IFN-I and TGFβ cooperatively activated human hepatic stellate cells (HepSC) in vitro. Mechanistically, IFN-I enhanced TGFβ-induced SMAD2/3 activation in HepSC. Finally, blockade of IFN-I signaling reversed HIV/cART-induced liver diseases in humanized mice. Consistent with the findings in humanized mice with HIV-1 and cART, we detected elevated markers of liver injury, M2-like macrophages, and of interferon signaling in blood specimens from PLWH over healthy individuals. These findings identify the IFN-I/M2LM/HepSC axis in HIV/cART-induced liver diseases and suggest that inhibiting IFN-I signaling or M2LM may provide a novel therapeutic strategy for treating HIV/cART-associated liver diseases in PLWH under ART.
James Ahodantin, Kouki Nio, Masaya Funaki, Xuguang Zhai, Eleanor Wilson, Shyamasundaran Kottilil, Liang Cheng, Guangming Li, Lishan Su
We describe a new mechanism responsible for Systemic Lupus Erythematosus (SLE). In humans with SLE and in two SLE murine models, there is marked enrichment of isolevuglandin (isoLG)-adducted proteins in monocytes and dendritic cells (DCs). We found that antibodies form against isoLG adducts in both SLE-prone mice and humans with SLE. In addition, isoLG ligation of the transcription factor PU.1 at a critical DNA binding site markedly reduces transcription of all C1q subunits. Treatment of SLE prone mice with the specific isoLG scavenger 2-hydroxybenzlyamine (2HOBA) ameliorates parameters of autoimmunity including plasma cell expansion, circulating IgG levels, and anti-dsDNA antibody titers. 2-HOBA also lowers blood pressure, attenuates renal injury, and reduces inflammatory gene expression uniquely in C1q expressing dendritic cells. Thus, isoLG adducts play an essential role in the genesis and maintenance of systemic autoimmunity and hypertension in SLE.
David M. Patrick, Néstor de la Visitación, Jaya Krishnan, Wei Chen, Michelle J. Ormseth, C. Michael Stein, Sean S. Davies, Venkataraman Amarnath, Leslie J. Crofford, Jonathan M. Williams, Shilin Zhao, Charles D. Smart, Sergey Dikalov, Anna Dikalova, Liang Xiao, Justin P. Van Beusecum, Mingfang Ao, Agnes B. Fogo, Annet Kirabo, David G. Harrison
Chronic type 2 (T2) inflammatory diseases of the respiratory tract are characterized by mucus overproduction and disordered mucociliary function, which are largely attributed to the effects of IL-13 on common epithelial cell types (mucus secretory and ciliated cells). The role of rare cells in airway T2 inflammation is less clear, though tuft cells have been shown to be critical in the initiation of T2 immunity in the intestine. Using bulk and single cell RNA sequencing of airway epithelium and mouse modeling, we find that IL-13 expands and programs airway tuft cells towards eicosanoid metabolism, and that tuft cell deficiency leads to a reduction in airway prostaglandin E2 (PGE2)concentration. Allergic airway epithelia bear a signature of prostaglandin E2 activation, and PGE2 activation leads to CFTR-dependent ion and fluid secretion and accelerated mucociliary transport. Together these data reveal a role for tuft cells in regulating epithelial mucociliary function in the allergic airway.
Maya E Kotas, Camille M. Moore, Jose G. Gurrola II, Steven D. Pletcher, Andrew N. Goldberg, Raquel Alvarez, Sheyla Yamato, Preston E. Bratcher, Ciaran A. Shaughnessy, Pamela L. Zeitlin, Irene H Zhang, Yingchun Li, Michael T. Montgomery, Keehoon Lee, Emily K. Cope, Richard M. Locksley, Max A. Seibold, Erin D. Gordon
Preterm infants are susceptible to bloodstream infection by coagulase-negative staphylococci (CONS) that can lead to sepsis. High parenteral glucose supplement is commonly used to support their growth and energy expenditure, but may exceed endogenous regulation during infection, causing dysregulated immune response and clinical deterioration. Using a preterm piglet model of neonatal CONS sepsis induced by Staphylococcus epidermidis infection, we demonstrate the delicate interplay between immunity and glucose metabolism to regulate the host infection response. Circulating glucose levels, glycolysis and inflammatory response to infection are closely connected across the states of tolerance, resistance and immunoparalysis. Further, high parenteral glucose provision during infection induces hyperglycemia, elevated glycolysis and inflammation, leading to metabolic acidosis and sepsis, whereas glucose restricted individuals are clinically unaffected with increased gluconeogenesis to maintain moderate hypoglycemia. Finally, standard glucose supply maintaining normoglycemia or pharmacological glycolysis inhibition enhances bacterial clearance and dampens inflammation but fails to prevent sepsis. Our results uncover how blood glucose and glycolysis controls circulating immune responses, in turn determining the clinical fate of CONS infected preterm individuals. This questions the current practice of parenteral glucose supply for preterm infants during infection.
Tik Muk, Anders Brunse, Nicole L. Henriksen, Karoline Aasmul-Olsen, Duc Ninh Nguyen
Inflammation of the esophageal epithelium is a hallmark of eosinophilic esophagitis (EoE), an emerging chronic allergic disease. Herein, we probed human esophageal epithelial cells at single-cell resolution during homeostasis and EoE. During allergic inflammation, the epithelial differentiation program was blocked, leading to loss of KRT6high differentiated populations and expansion of TOP2high proliferating and DSPhigh, SERPINB3high transitioning populations; however, there was stability of the stem cell–enriched PDPNhigh basal epithelial compartment. This differentiation program blockade was associated with dysregulation of transcription factors, including nuclear receptor signalers, in the most differentiated epithelial cells and altered NOTCH-related cell-to-cell communication. Each epithelial population expressed genes with allergic disease risk variants, supporting their functional interplay. The esophageal epithelium differed notably between EoE in histologic remission and controls, indicating that remission is a transitory state poised to relapse. Collectively, our data uncover the dynamic nature of the inflamed human esophageal epithelium and provide a framework to better understand esophageal health and disease.
Mark Rochman, Ting Wen, Michael Kotliar, Phillip J. Dexheimer, Netali Ben-Baruch Morgenstern, Julie M. Caldwell, Hee-Woong Lim, Marc E. Rothenberg
Systemic sclerosis (SSc) is a fibrotic autoimmune disease characterized by pathogenic activation of fibroblasts enhanced by local oxidative stress. The tyrosine phosphatase PTP4A1 was identified as a critical promoter of TGF-β signaling in SSc. Oxidative stress is known to functionally inactivate tyrosine phosphatases. Here, we assessed whether oxidation of PTP4A1 modulates its profibrotic action and found that PTP4A1 forms a complex with the kinase SRC in scleroderma fibroblasts, but surprisingly, oxidative stress enhanced rather than reduced PTP4A1’s association with SRC and its profibrotic action. Through structural assessment of the oxo-PTP4A1-SRC complex, we unraveled an unexpected mechanism whereby oxidation of a tyrosine phosphatase promotes its function through modification of its protein complex. Considering the importance of oxidative stress in the pathogenesis of SSc and fibrosis, our findings suggest routes for leveraging PTP4A1 oxidation as a potential strategy for developing antifibrotic agents.
Ruiyuan Zhang, Ganesan Senthil Kumar, Uwe Hansen, Martina Zoccheddu, Cristiano Sacchetti, Zachary J. Holmes, Megan C. Lee, Denise Beckmann, Yutao Wen, Zbigniew Mikulski, Shen Yang, Eugenio Santelli, Rebecca Page, Francesco Boin, Wolfgang Peti, Nunzio Bottini
Elucidating how resident enteric bacteria interact with their hosts to promote health or inflammation is of central importance to diarrheal and inflammatory bowel diseases across species. Here, we integrate the microbial and chemical microenvironment of a patient’s ileal mucosa with their clinical phenotype and genotype to identify factors favoring the growth and virulence of Adherent and Invasive E. coli (AIEC) linked to Crohn’s disease. We determine that the ileal niche of AIEC is characterized by inflammation, dysbiosis, coculture of Enterococcus and oxidative stress. We discover that mucosal metabolites support general growth of ileal E. coli, with a selective effect of ethanolamine on AIEC that is augmented by co-metabolism of ileitis-associated amino acids and glutathione, and symbiosis-associated fucose. This metabolic plasticity is facilitated by the eut and pdu microcompartments, amino acid metabolism, γ-glutamyl-cycle and pleotropic stress responses. We link metabolism to virulence, finding that ethanolamine and glutamine enhance AIEC motility, infectivity and pro-inflammatory responses in vitro. We connect use of ethanolamine to intestinal inflammation, and L-fuculose phosphate aldolase (fucA) to symbiosis in AIEC mono-associated IL10-/- mice. Collectively, we establish that AIEC are pathoadapted to utilize mucosal metabolites associated with health and inflammation for growth and virulence, enabling the transition from symbiont to pathogen in a susceptible host.
Shiying Zhang, Xochitl C, Morgan, Belgin Dogan, Francois-Pierre Martin, Susan R. Strickler, Akihiko Oka, Jeremy Herzog, Bo Liu, Scot E. Dowd, Curtis Huttenhower, Matthieu Pichaud, Esra I. Dogan, Jack Satsangi, Randy Longman, Rhonda Yantiss, Lukas A. Mueller, Ellen Scherl, R. Balfour Sartor, Kenneth W. Simpson
Immunoproteasomes regulate the degradation of ubiquitin-coupled proteins and generate peptides that are preferentially presented by MHC class I. Mutations in immunoproteasome subunits lead to immunoproteasome dysfunction, which causes proteasome-associated autoinflammatory syndromes (PRAAS) characterized by nodular erythema and partial lipodystrophy. It remains unclear, however, how immunoproteasome dysfunction leads to inflammatory symptoms. Here, we established mice harboring a mutation in Psmb8 (Psmb8-KI mice) and addressed this question. Psmb8-KI mice showed higher susceptibility to imiquimod-induced skin inflammation (IMS). Blockade of IL-6 or TNF-α partially suppressed IMS in both control and Psmb8-KI mice, but there was still more residual inflammation in the Psmb8-KI mice than in the control mice. DNA microarray analysis showed that treatment of J774 cells with proteasome inhibitors increased the expression of the Cxcl9 and Cxcl10 genes. Deficiency in Cxcr3, the gene encoding the receptor of CXCL9 and CXCL10, in control mice did not change IMS susceptibility, while deficiency in Cxcr3 in Psmb8-KI mice ameliorated IMS. Taken together, these findings demonstrate that this mutation in Psmb8 leads to hyperactivation of the CXCR3 pathway, which is responsible for the increased susceptibility of Psmb8-KI mice to IMS. These data suggest the CXCR3/CXCL10 axis as a new molecular target for treating PRAAS.
Yuki Sasaki, Hideki Arimochi, Kunihiro Otsuka, Hiroyuki Kondo, Shin-ichi Tsukumo, Koji Yasutomo
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