scholarly journals Macrophages mediate lung inflammation in a mouse model of ischemic acute kidney injury

2012 ◽  
Vol 302 (4) ◽  
pp. F421-F432 ◽  
Author(s):  
Christopher Altmann ◽  
Ana Andres-Hernando ◽  
Rachel H. McMahan ◽  
Nilesh Ahuja ◽  
Zhibin He ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Lung Inflammation ◽  
Kidney Injury ◽  
Capillary Leak ◽  
Blood Monocytes ◽  
Wild Type ◽  
Macrophage Depletion ◽  
Reduced Renal Function

Serum IL-6 is increased in acute kidney injury (AKI) and inhibition of IL-6 reduces AKI-mediated lung inflammation. We hypothesized that circulating monocytes produce IL-6 and that alveolar macrophages mediate lung inflammation after AKI via chemokine (CXCL1) production. To investigate systemic and alveolar macrophages in lung injury after AKI, sham operation or 22 min of renal pedicle clamping (AKI) was performed in three experimental settings: 1) systemic macrophage depletion via diphtheria toxin (DT) injection to CD11b-DTR transgenic mice, 2) DT injection to wild-type mice, and 3) alveolar macrophage depletion via intratracheal (IT) liposome-encapsulated clodronate (LEC) administration to wild-type mice. In mice with AKI and systemic macrophage depletion (CD11b-DTR transgenic administered DT) vs. vehicle-treated AKI, blood monocytes and lung interstitial macrophages were reduced, renal function was similar, serum IL-6 was increased, lung inflammation was improved, lung CXCL1 was reduced, and lung capillary leak was increased. In wild-type mice with AKI administered DT vs. vehicle, serum IL-6 was increased. In mice with AKI and alveolar macrophage depletion (IT-LEC) vs. AKI with normal alveolar macrophage content, blood monocytes and lung interstitial macrophages were similar, alveolar macrophages were reduced, renal function was similar, lung inflammation was improved, lung CXCL1 was reduced, and lung capillary leak was increased. In conclusion, administration of DT in AKI is proinflammatory, limiting the use of the DTR-transgenic model to study systemic effects of AKI. Mice with AKI and either systemic mononuclear phagocyte depletion or alveolar macrophage depletion had reduced lung inflammation and lung CXCL1, but increased lung capillary leak; thus, mononuclear phagocytes mediate lung inflammation, but they protect against lung capillary leak after ischemic AKI. Since macrophage activation and chemokine production are key events in the development of acute lung injury (ALI), these data provide further evidence that AKI may cause ALI.

scholarly journals Circulating IL-6 upregulates IL-10 production in splenic CD4 + T cells and limits acute kidney injury–induced lung inflammation

2017 ◽  
Vol 91 (5) ◽  
pp. 1057-1069 ◽  
Author(s):  
Ana Andres-Hernando ◽  
Kayo Okamura ◽  
Rhea Bhargava ◽  
Carol M. Kiekhaefer ◽  
Danielle Soranno ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
T Cells ◽  
Cd4 T Cells ◽  
Lung Inflammation ◽  
Kidney Injury

scholarly journals Proximal tubule-specific overexpression of netrin-1 suppresses acute kidney injury-induced interstitial fibrosis and glomerulosclerosis through suppression of IL-6/STAT3 signaling

2013 ◽  
Vol 304 (8) ◽  
pp. F1054-F1065 ◽  
Author(s):  
Punithavathi Ranganathan ◽  
Calpurnia Jayakumar ◽  
Ganesan Ramesh
Keyword(s):  
Acute Kidney Injury ◽  
Epithelial Cells ◽  
Interstitial Fibrosis ◽  
Kidney Injury ◽  
Transgenic Animals ◽  
Acute Injury ◽  
Tubular Epithelial Cells ◽  
Wild Type ◽  
Proximal Tubular Epithelial Cells ◽  
Proximal Tubular

Acute kidney injury-induced organ fibrosis is recognized as a major risk factor for the development of chronic kidney disease, which remains one of the leading causes of death in the developed world. However, knowledge on molecules that may suppress the fibrogenic response after injury is lacking. In ischemic models of acute kidney injury, we demonstrate a new function of netrin-1 in regulating interstitial fibrosis. Acute injury was promptly followed by a rise in serum creatinine in both wild-type and netrin-1 transgenic animals. However, the wild-type showed a slow recovery of kidney function compared with netrin-1 transgenic animals and reached baseline by 3 wk. Histological examination showed increased infiltration of interstitial macrophages, extensive fibrosis, reduction of capillary density, and glomerulosclerosis. Collagen IV and α-smooth muscle actin expression was absent in sham-operated kidneys; however, their expression was significantly increased at 2 wk and peaked at 3 wk after reperfusion. These changes were reduced in the transgenic mouse kidney, which overexpresses netrin-1 in proximal tubular epithelial cells. Fibrosis was associated with increased expression of IL-6 and extensive and chronic activation of STAT3. Administration of IL-6 exacerbated fibrosis in vivo in wild-type, but not in netrin-1 transgenic mice kidney and increased collagen I expression and STAT3 activation in vitro in renal epithelial cells subjected to hypoxia-reoxygenation, which was suppressed by netrin-1. Our data suggest that proximal tubular epithelial cells may play a prominent role in interstitial fibrosis and that netrin-1 could be a useful therapeutic agent for treating kidney fibrosis.

scholarly journals TAK1 deficiency attenuates cisplatin-induced acute kidney injury

2020 ◽  
Vol 318 (1) ◽  
pp. F209-F215 ◽  
Author(s):  
Jun Zhou ◽  
Changlong An ◽  
Xiaogao Jin ◽  
Zhaoyong Hu ◽  
Robert L. Safirstein ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Proximal Tubule ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Kidney Injury ◽  
Transforming Growth Factor Β ◽  
Tubular Epithelial Cell ◽  
Tubular Damage ◽  
Wild Type ◽  
Deficient Mice

Cisplatin can cause acute kidney injury (AKI), but the molecular mechanisms are not well understood. The objective of the present study was to examine the role of transforming growth factor-β-activated kinase-1 (TAK1) in the pathogenesis of cisplatin-induced AKI. Wild-type mice and proximal tubule TAK1-deficient mice were treated with vehicle or cisplatin. Compared with wild-type control mice, proximal tubule TAK1-deficient mice had less severe kidney dysfunction, tubular damage, and apoptosis after cisplatin–induced AKI. Furthermore, conditional disruption of TAK1 in proximal tubular epithelial cells reduced caspase-3 activation, proinflammatory molecule expression, and JNK phosphorylation in the kidney in cisplatin-induced AKI. Taken together, cisplatin activates TAK1-JNK signaling pathway to promote tubular epithelial cell apoptosis and inflammation in cisplatin-induced AKI. Targeting TAK1 could be a novel therapeutic strategy against cisplatin-induced AKI.

scholarly journals Toll-like Receptor 7 Contributes to Inflammation, Organ Injury, and Mortality in Murine Sepsis

2019 ◽  
Vol 131 (1) ◽  
pp. 105-118 ◽  
Author(s):  
Wenling Jian ◽  
Lili Gu ◽  
Brittney Williams ◽  
Yan Feng ◽  
Wei Chao ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Immune Responses ◽  
Knockout Mice ◽  
Cecal Ligation ◽  
Kidney Injury ◽  
Innate Immune ◽  
Organ Injury ◽  
Innate Immune Responses ◽  
Toll Like Receptor ◽  
Wild Type

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Sepsis remains a critical illness with high mortality. The authors have recently reported that mouse plasma RNA concentrations are markedly increased during sepsis and closely associated with its severity. Toll-like receptor 7, originally identified as the sensor for single-stranded RNA virus, also mediates host extracellular RNA-induced innate immune responses in vitro and in vivo. Here, the authors hypothesize that innate immune signaling via Toll-like receptor 7 contributes to inflammatory response, organ injury, and mortality during polymicrobial sepsis. Methods Sepsis was created by (1) cecal ligation and puncture or (2) stool slurry peritoneal injection. Wild-type and Toll-like receptor 7 knockout mice, both in C57BL/6J background, were used. The following endpoints were measured: mortality, acute kidney injury biomarkers, plasma and peritoneal cytokines, blood bacterial loading, peritoneal leukocyte counts, and neutrophil phagocytic function. Results The 11-day overall mortality was 81% in wild-type mice and 48% in Toll-like receptor 7 knockout mice after cecal ligation and puncture (N = 27 per group, P = 0.0031). Compared with wild-type septic mice, Toll-like receptor 7 knockout septic mice also had lower sepsis severity, attenuated plasma cytokine storm (wild-type vs. Toll-like receptor 7 knockout, interleukin-6: 43.2 [24.5, 162.7] vs. 4.4 [3.1, 12.0] ng/ml, P = 0.003) and peritoneal inflammation, alleviated acute kidney injury (wild-type vs. Toll-like receptor 7 knockout, neutrophil gelatinase-associated lipocalin: 307 ± 184 vs.139 ± 41-fold, P = 0.0364; kidney injury molecule-1: 40 [16, 49] vs.13 [4, 223]-fold, P = 0.0704), lower bacterial loading, and enhanced leukocyte peritoneal recruitment and phagocytic activities at 24 h. Moreover, stool slurry from wild-type and Toll-like receptor 7 knockout mice resulted in similar level of sepsis severity, peritoneal cytokines, and leukocyte recruitment in wild-type animals after peritoneal injection. Conclusions Toll-like receptor 7 plays an important role in the pathogenesis of polymicrobial sepsis by mediating host innate immune responses and contributes to acute kidney injury and mortality.

scholarly journals Macrophages are not the source of injurious interleukin-18 in ischemic acute kidney injury in mice

2009 ◽  
Vol 296 (3) ◽  
pp. F535-F542 ◽  
Author(s):  
Zhibin He ◽  
Belda Dursun ◽  
Dong-Jin Oh ◽  
Lawrence Lu ◽  
Sarah Faubel ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Adoptive Transfer ◽  
Kidney Injury ◽  
Peritoneal Macrophages ◽  
Raw 264.7 Cells ◽  
Wild Type ◽  
Interleukin 18 ◽  
Caspase 1 ◽  
Outer Stripe ◽  
Ischemic Acute Kidney Injury

We previously reported in ischemic acute kidney injury (AKI) in mice that caspase-1-mediated production of interleukin-18 (IL-18) is pathogenic and that macrophage depletion by liposome-encapsulated clodronate (LEC) is protective. Therefore, our aim was to determine whether macrophages are a source of IL-18 in ischemic AKI in mice. On immunofluorescence staining of the outer stripe of outer medulla, the number of macrophages double stained for CD11b and IL-18 was significantly increased in AKI and significantly decreased by LEC. Adoptive transfer of RAW 264.7 cells, a mouse macrophage line that constitutively expresses IL-18 mRNA, reversed the functional protection against AKI in both LEC-treated wild-type and caspase-1 −/− mice. To test whether IL-18 in macrophages is necessary to cause AKI, we adoptively transferred macrophages in which IL-18 was inhibited. Peritoneal macrophages isolated from wild-type mice, IL-18 binding protein transgenic (IL-18 BP Tg) mice, and IL-18 −/− mice were used. IL-18 BP Tg mice overexpress human IL-18 BP and exhibit decreased biological activity of IL-18. Adoptive transfer of peritoneal macrophages from wild-type as well as IL-18 BP Tg and IL-18 −/− mice reversed the functional protection against AKI in LEC-treated mice. In summary, adoptive transfer of RAW cells, that constitutively express IL-18, reverses the functional protection in macrophage-depleted wild-type and caspase-1 −/− mice with AKI. However, adoptive transfer of peritoneal macrophages in which IL-18 function was inhibited also reverses the functional protection in macrophage-depleted mice. In conclusion, IL-18 from adoptive transfer of macrophages is not sufficient to cause ischemic AKI.

Contribution of alveolar macrophages to the response of the TIMP-3 null lung during a septic insult

2007 ◽  
Vol 293 (3) ◽  
pp. L779-L789 ◽  
Author(s):  
Erica L. Martin ◽  
Tanya A. Sheikh ◽  
Kevin J. Leco ◽  
James F. Lewis ◽  
Ruud A. W. Veldhuizen
Keyword(s):  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Lung Mechanics ◽  
Wild Type ◽  
Pulmonary Compliance ◽  
Alveolar Structure ◽  
Tissue Degradation ◽  
Septic Insult ◽  
Metalloproteinase Activity

Mice deficient in tissue inhibitor of metalloproteinase-3 (TIMP-3) develop an emphysema-like phenotype involving increased pulmonary compliance, tissue degradation, and matrix metalloproteinase (MMP) activity. After a septic insult, they develop a further increase in compliance that is thought to be a result of heightened metalloproteinase activity produced by the alveolar macrophage, potentially modeling an emphysemic exacerbation. Therefore, we hypothesized that TIMP-3 null mice lacking alveolar macrophages would not be susceptible to the altered lung function associated with a septic insult. TIMP-3 null and wild-type (WT) mice were depleted of alveolar macrophages before the induction of a septic insult and assessed for alteration in lung mechanics, alveolar structure, metalloproteinase levels, and inflammation. The results showed that TIMP-3 null mice lacking alveolar macrophages were protected from sepsis-induced alterations in lung mechanics, particularly pulmonary compliance, a finding that was supported by changes in alveolar structure. Additionally, changes in lung mechanics involved primarily peripheral tissue vs. central airways as determined using the flexiVent system. From investigation into possible molecules that could cause these alterations, it was found that although several proteases and inflammatory mediators were increased during the septic response, only MMP-7 was attenuated after macrophage depletion. In conclusion, the alveolar macrophage is essential for the TIMP-3 null sepsis-induced compliance alterations. This response may be mediated in part by MMP-7 activity but occurs independently of inflammatory cytokine and/or chemokine concentrations.

scholarly journals Acute Kidney Injury Reduces Phagocytic and Microbicidal Capacities of Alveolar Macrophages

2013 ◽  
Vol 31 (2-3) ◽  
pp. 179-188 ◽  
Author(s):  
Reinaldo C. Silva ◽  
Maristella A. Landgraf ◽  
Matheus Corrêa-Costa ◽  
Patricia Semedo ◽  
Marcos A. Cenedeze ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Alveolar Macrophages ◽  
Kidney Injury

scholarly journals Monocyte-derived alveolar macrophages drive lung fibrosis and persist in the lung over the life span

2017 ◽  
Vol 214 (8) ◽  
pp. 2387-2404 ◽  
Author(s):  
Alexander V. Misharin ◽  
Luisa Morales-Nebreda ◽  
Paul A. Reyfman ◽  
Carla M. Cuda ◽  
James M. Walter ◽  
...  
Keyword(s):  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Lung Fibrosis ◽  
Relative Importance ◽  
Macrophage Differentiation ◽  
Macrophage Depletion ◽  
Human Alveolar Macrophages ◽  
Genetic Deletion ◽  
One Year ◽  
Normal Lungs

Little is known about the relative importance of monocyte and tissue-resident macrophages in the development of lung fibrosis. We show that specific genetic deletion of monocyte-derived alveolar macrophages after their recruitment to the lung ameliorated lung fibrosis, whereas tissue-resident alveolar macrophages did not contribute to fibrosis. Using transcriptomic profiling of flow-sorted cells, we found that monocyte to alveolar macrophage differentiation unfolds continuously over the course of fibrosis and its resolution. During the fibrotic phase, monocyte-derived alveolar macrophages differ significantly from tissue-resident alveolar macrophages in their expression of profibrotic genes. A population of monocyte-derived alveolar macrophages persisted in the lung for one year after the resolution of fibrosis, where they became increasingly similar to tissue-resident alveolar macrophages. Human homologues of profibrotic genes expressed by mouse monocyte-derived alveolar macrophages during fibrosis were up-regulated in human alveolar macrophages from fibrotic compared with normal lungs. Our findings suggest that selectively targeting alveolar macrophage differentiation within the lung may ameliorate fibrosis without the adverse consequences associated with global monocyte or tissue-resident alveolar macrophage depletion.

scholarly journals P0547THE DELETION OF AKT1 ATTENUATES RENAL FIBROSIS AND TUBULAR EPITHELIAL-MESENCHYMAL TRANSITION DURING ACUTE KIDNEY INJURY TO CHRONIC KIDNEY DISEASE PROGRESSION

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Byung Min Ye ◽  
Il Young Kim ◽  
Min Jeong Kim ◽  
Soo Bong Lee ◽  
Dong Won Lee ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Acute Kidney Injury ◽  
Kidney Disease ◽  
Renal Fibrosis ◽  
Epithelial Mesenchymal Transition ◽  
Kidney Injury ◽  
Wild Type ◽  
Ckd Progression ◽  
Mesenchymal Transition ◽  
Tgf Β1

Abstract Background and Aims Acute kidney injury (AKI) is an underestimated, yet important risk factor for the development of chronic kidney disease (CKD), which is characterized by the tubulointerstitial fibrosis and tubular epithelial-mesenchymal transition (EMT). Akt has been reported to be involved in renal fibrosis and EMT. Thus, we investigated the role of Akt1, one of the three Akt isoforms, in the murine model of AKI to CKD progression. Method We subjected the wild type and Akt1−/− mice to unilateral ischemia-reperfusion injury (UIRI). UIRI was induced by clamping the left renal artery for 30 min followed by reperfusion. After 6 weeks of UIRI, the renal fibrosis and EMT were assessed by histology, immunohistochemistry, and western blot. Results After 6 weeks after UIRI, we found that Akt1, not Akt2 or Akt3, was activated in UIRI-kidney. The tubulointerstitial fibrosis was significantly alleviated in Akt1−/− mice compared with the wild type (WT) mice. Besides, the deletion of Akt1 decreased the expression of the vimentin and α-SMA and increased the expression of E-cadherin, indicating the suppression of tubular EMT. However, there was no difference in the activity of TGF-β1/Smad signalling, which is the potent inducer of renal fibrosis and EMT, between WT mice and Akt1−/− mice. The deletion of Akt1 also increased the GSK-3β activity and decreased the expression of β-catenin, Snail, and twist1. Conclusion Our findings demonstrate that the deletion of Akt1 attenuates the renal fibrosis and tubular EMT independently of TGF-β1/Smad signalling during the AKI to CKD progression. Akt1 may be the therapeutic target against the AKI to CKD progression.

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