scholarly journals Natural polymorphism of Ym1 regulates pneumonitis through alternative activation of macrophages

2020 ◽  
Vol 6 (43) ◽  
pp. eaba9337
Author(s):  
Wenhua Zhu ◽  
Erik Lönnblom ◽  
Michael Förster ◽  
Martina Johannesson ◽  
Pei Tao ◽  
...  

We have positionally cloned the Ym1 gene, with a duplication and a promoter polymorphism, as a major regulator of inflammation. Mice with the RIIIS/J haplotype, with the absence of Ym1 expression, showed reduced susceptibility to mannan-enhanced collagen antibody–induced arthritis and to chronic arthritis induced by intranasal exposure of mannan. Depletion of lung macrophages alleviated arthritis, whereas intranasal supplement of Ym1 protein to Ym1-deficient mice reversed the disease, suggesting a key role of Ym1 for inflammatory activity by lung macrophages. Ym1-deficient mice with pneumonitis had less eosinophil infiltration, reduced production of type II cytokines and IgG1, and skewing of macrophages toward alternative activation due to enhanced STAT6 activation. Proteomics analysis connected Ym1 polymorphism with changed lipid metabolism. Induced PPAR-γ and lipid metabolism in Ym1-deficient macrophages contributed to cellular polarization. In conclusion, the natural polymorphism of Ym1 regulates alternative activation of macrophages associated with pulmonary inflammation.

2019 ◽  
Vol 316 (2) ◽  
pp. L391-L399 ◽  
Author(s):  
Grigorij Schleifer ◽  
Eizo Marutani ◽  
Michele Ferrari ◽  
Rohit Sharma ◽  
Owen Skinner ◽  
...  

Hypoxic pulmonary vasoconstriction (HPV) is a physiological vasomotor response that maintains systemic oxygenation by matching perfusion to ventilation during alveolar hypoxia. Although mitochondria appear to play an essential role in HPV, the impact of mitochondrial dysfunction on HPV remains incompletely defined. Mice lacking the mitochondrial complex I (CI) subunit Ndufs4 ( Ndufs4−/−) develop a fatal progressive encephalopathy and serve as a model for Leigh syndrome, the most common mitochondrial disease in children. Breathing normobaric 11% O2 prevents neurological disease and improves survival in Ndufs4−/− mice. In this study, we found that either genetic Ndufs4 deficiency or pharmacological inhibition of CI using piericidin A impaired the ability of left mainstem bronchus occlusion (LMBO) to induce HPV. In mice breathing air, the partial pressure of arterial oxygen during LMBO was lower in Ndufs4−/− and in piericidin A-treated Ndufs4+/+ mice than in respective controls. Impairment of HPV in Ndufs4−/− mice was not a result of nonspecific dysfunction of the pulmonary vascular contractile apparatus or pulmonary inflammation. In Ndufs4-deficient mice, 3 wk of breathing 11% O2 restored HPV in response to LMBO. When compared with Ndufs4−/− mice breathing air, chronic hypoxia improved systemic oxygenation during LMBO. The results of this study show that, when breathing air, mice with a congenital Ndufs4 deficiency or chemically inhibited CI function have impaired HPV. Our study raises the possibility that patients with inborn errors of mitochondrial function may also have defects in HPV.


2018 ◽  
Vol 315 (2) ◽  
pp. E218-E228 ◽  
Author(s):  
Difei Wang ◽  
Huiying Cong ◽  
Xiaoli Wang ◽  
Yanli Cao ◽  
Shoichiro Ikuyama ◽  
...  

PycnogenolR (PYC), a combination of active flavonoids derived from French maritime pine bark, is a natural antioxidant that has various pharmacological activities. Here, we investigated the beneficial effect of PYC on diet-induced hepatic steatosis. Apolipoprotein E (ApoE)-deficient male mice were administered PYC at oral doses of 30 or 100 mg·kg−1·day−1 for 2 wk in advance and were then fed a high-cholesterol and -fat diet (HCD) for 8 wk. Biochemical, immunohistochemical, and gene expression analyses were conducted to explore the effect of PYC on lipid metabolism in ApoE-deficient mice on a HCD. Short-term treatment with HCD in ApoE-deficient mice induced hepatic injuries, such as lipid metabolism disorder and hepatic histopathological changes. We found that PYC reduced body weight and the increase of serum lipids that had been caused by HCD. Supplementation of PYC significantly reduced lipid deposition in the liver, as shown by the lowered hepatic lipid content and histopathological lesions. We subsequently detected genes related to lipid metabolism and inflammatory cytokines. The study showed that PYC markedly suppressed the expression of genes related to hepatic lipogenesis, fatty acid uptake, and lipid storage while increasing the lipolytic gene, which thus reduced hepatic lipid content. Furthermore, PYC mainly reduced the expression of inflammatory cytokines and the infiltration of inflammatory cells, which were resistant to the development of hepatic steatosis. These results demonstrate that PYC protects against the occurrence and development of hepatic steatosis and may provide a new prophylactic approach for nonalcoholic fatty liver disease (NAFLD).


2020 ◽  
Vol 27 (2) ◽  
pp. 108-116
Author(s):  
Hyelim Park ◽  
Ah-Yeoun Jung ◽  
Chung-Soon Chang ◽  
Young Hyo Kim

Background and Objectives: The immunomodulatory effects and mechanism of probiotics in allergic airway disease are largely unknown. We studied whether <i>Bacillus clausii</i> (BC), a probiotic derived from mudflats, had anti-allergic effects and compared the results with those of <i>Lactobacillus paracasei</i> (LP). We also examined whether the anti-allergic mechanisms of probiotics are associated with hypoxia signaling.Materials and Method: Forty-two BALB/c mice were randomly assigned to six experimental groups: controls, ovalbumin (OVA)-induced mice for inducing asthma, and OVA-induced mice that were orally administered LP or BC, at 1×10<sup>9</sup> or 5×10<sup>9</sup> CFU/mL each. We performed differential cell count testing on bronchoalveolar lavage fluid (BALF), lung histopathology, serum totals and OVA-specific IgE and IgG1 assessments, Th2 cytokine titers (IL-4, IL-5) in BALF and pulmonary parenchyma, quantitative PCR for <i>heme oxygenase (HO)-1</i> and <i>Hif-1α</i>, and immunohistochemistry.Results: Compared to the OVA group mice, OVA-sensitized mice treated with LP or BC showed significantly reduced numbers of eosinophils and neutrophils in the BALF (p<0.05). Both probiotics also significantly reduced pulmonary inflammation and eosinophil infiltration. Mice in the LP or BC group had a substantially lower titer of IL-4 and IL-5 in BALF, and decreased IL-4 and IL-5 expression in the lung parenchyma. Real-time PCR and immunohistochemistry showed that both LP and BC could significantly suppress <i>HO-1</i> and <i>Hif-1α</i> expression in asthmatic mice (p<0.05).Conclusion: BC can attenuate murine allergic asthma by regulating HIF-1α signaling, and its anti-allergic effect is comparable to that of LP.


2011 ◽  
Vol 31 (6) ◽  
pp. 434-439 ◽  
Author(s):  
Junichi Tsuyusaki ◽  
Fuminobu Kuroda ◽  
Yoshitoshi Kasuya ◽  
Shunsuke Ishizaki ◽  
Keita Yamauchi ◽  
...  

2019 ◽  
Vol 130 (3) ◽  
pp. 404-413 ◽  
Author(s):  
Tim Rahmel ◽  
Katharina Rump ◽  
Jürgen Peters ◽  
Michael Adamzik

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background The aquaporin-5 (AQP5) –1364A/C promoter single-nucleotide polymorphism is associated with an altered AQP5 expression and mortality in sepsis. Because AQP5 expression alters neutrophil cell migration, it could affect pulmonary inflammation and survival in bacterially evoked acute respiratory distress syndrome. Accordingly, the authors tested the hypotheses that the AC/CC genotype in patients with bacterially evoked pneumonia resulting in acute respiratory distress syndrome is associated with (1) attenuated pulmonary inflammation and (2) higher 30-day survival. Methods In this prospective, observational study, bronchoalveolar lavage and blood sampling were performed within 24 h of intensive care unit admission. In 136 Caucasian patients with bacterially evoked acute respiratory distress syndrome, genotype of the AQP5 –1364A/C promoter polymorphism, bronchoalveolar lavage total protein, albumin, white cell concentrations, and lactate dehydrogenase activity were measured to evaluate the relationship between genotypes and survival. Results AC/CC patients as well as survivors showed lower bronchoalveolar lavage protein (0.9 mg/ml vs. 2.3 mg/ml, P &lt; 0.001 and 1.6 mg/ml vs. 2.6 mg/ml, P = 0.035), albumin (0.2 mg/ml vs. 0.6 mg/ml, P = 0.019 and 0.3 mg/ml vs. 0.6 mg/ml, P = 0.028), leukocytes (424 /ml vs. 1,430/ml; P = 0.016 and 768 /ml vs. 1,826/ml; P = 0.025), and lactate dehydrogenase activity (82 U/l vs. 232 U/l; P = 0.006 and 123 U/l vs. 303 U/l; P = 0.020). Thirty-day survival was associated with AQP5 –1364A/C genotypes (P = 0.005), with survival of 62% for AA genotypes (58 of 93) but 86% for C-allele carriers (37 of 43). Furthermore, multiple proportional hazard analysis revealed the AA genotype was at high risk for death within 30 days (hazard ratio, 3.53; 95% CI, 1.38 to 9.07; P = 0.009). Conclusions In acute respiratory distress syndrome attributable to bacterial pneumonia, the C-allele of the AQP5 –1364A/C promoter polymorphism is associated with an attenuated pulmonary inflammation and higher 30-day survival. Thus, the AQP5 genotype impacts on inflammation and prognosis in acute respiratory distress syndrome.


2019 ◽  
Vol 20 (20) ◽  
pp. 4989 ◽  
Author(s):  
Yoshinori Tanino ◽  
Xintao Wang ◽  
Takefumi Nikaido ◽  
Kenichi Misa ◽  
Yuki Sato ◽  
...  

Syndecan-4 is a transmembrane heparan sulfate proteoglycan expressed in a variety of cells, and its heparan sulfate glycosaminoglycan side chains bind to several proteins exhibiting various biological roles. The authors have previously demonstrated syndecan-4′s critical roles in pulmonary inflammation. In the current study, however, its role in pulmonary fibrosis was evaluated. Wild-type and syndecan-4-deficient mice were injected with bleomycin, and several parameters of inflammation and fibrosis were analyzed. The mRNA expression of collagen and α-smooth muscle action (α-SMA) in lung tissues, as well as the histopathological lung fibrosis score and collagen content in lung tissues, were significantly higher in the syndecan-4-deficient mice. However, the total cell count and cell differentiation in bronchoalveolar lavage fluid were equivalent between the wild-type and syndecan-4-deficient mice. Although there was no difference in the TGF-β expression in lung tissues between the wild-type and syndecan-4-deficient mice, significantly more activation of Smad3 in lung tissues was observed in the syndecan-4-deficient mice compared to the wild-type mice. Furthermore, in the in vitro experiments using lung fibroblasts, the co-incubation of syndecan-4 significantly inhibited TGF-β-induced Smad3 activation, collagen and α-SMA upregulation. Moreover, syndecan-4 knock-down by siRNA increased TGF-β-induced Smad3 activation and upregulated collagen and α-SMA expression. These findings showed that syndecan-4 inhibits the development of pulmonary fibrosis, at least in part, through attenuating TGF-β signaling.


2018 ◽  
Vol 237 (2) ◽  
pp. 175-191 ◽  
Author(s):  
Jung-Yoon Heo ◽  
Ji-Eun Kim ◽  
Yongwook Dan ◽  
Yong-Woon Kim ◽  
Jong-Yeon Kim ◽  
...  

Clusterin is a secretory glycoprotein that is involved in multiple physiopathological processes, including lipid metabolism. Previous studies have shown that clusterin prevents hepatic lipid accumulation via suppression of sterol regulatory element-binding protein (SREBP) 1. In this study, we examined the role of clusterin in renal lipid accumulation in clusterin-knockout mice and NRK52e tubular epithelial cells. Clusterin deficiency increased the expression of SREBP1 and its target genes and decreased malonyl-CoA decarboxylase protein levels in the kidney. Expression of the endocytic receptor, megalin, and scavenger receptor class A was increased in clusterin-deficient mice. Functional analysis of lipid metabolism also revealed that lipid uptake and triglyceride synthesis were increased and fatty acid oxidation was reduced, leading to increased lipid accumulation in clusterin-deficient mice. These phenomena were accompanied by mesangial expansion, fibrosis and increased urinary protein-to-creatinine ratio. High-fat feeding aggravated these clusterin deficiency-induced pathological changes. Clusterin knockdown in NRK52e cells increased lipogenic gene expression and lipid levels, whereas overexpression of clusterin by treatment with adenovirus or recombinant clusterin protein suppressed lipogenic gene expression and lipid levels. Transforming growth factor-beta 1 (TGFB1) expression increased in the kidney of clusterin-deficient mice and suppression of TGFB1 in NRK52e cells suppressed lipid accumulation. These results suggest that clusterin deficiency induces renal lipid accumulation by dysregulating the expression of lipid metabolism-related factors and TGFB1, thereby leading to chronic kidney disease. Hence, clusterin may serve as a therapeutic target for lipid-induced chronic kidney disease.


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