scholarly journals The CXCL1-CXCR2 Axis Mediates Tubular Injury in Diabetic Nephropathy Through the Regulation of the Inflammatory Response

2021 ◽  
Vol 12 ◽  
Author(s):  
Hanfen Tang ◽  
Ming Yang ◽  
Yinghong Liu ◽  
Hong Liu ◽  
Lin Sun ◽  
...  

Diabetic nephropathy (DN) is one of the most severe complications of diabetes. Inflammation mediated by inflammatory factors is thought to accelerate the progression of renal damage in DN. However, which inflammatory factors mediate the inflammatory response in DN remains unclear. In this study, we determined that the CXCL1-mediated inflammatory response may play an essential role in DN progression through bioassays. Subsequently, we observed that the expression of CXCL1 and its receptor (CXCR2) was significantly increased in the kidneys of mice with HFD + STZ induced diabetes and DN patients. In addition, inhibition of the CXCL1/CXCR2 axis by repertaxin alleviates renal inflammation and pathological damage in the kidneys of db/db mice. Finally, we noted that the CXCL1/CXCR2 axis might lead to inflammatory damage through phosphorylated NF-κB and further activate the NLRP3 inflammasome. Our results revealed the role of the CXCL1/CXCR2 axis in DN progression for the first time, which may be a novel therapeutic target for DN.

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Yajing Wang ◽  
Wayne Lau ◽  
Erhe Gao ◽  
Walter Koch ◽  
Xin Ma

Anti-inflammatory and vascular protective actions of adiponectin (APN) are well-recognized. However, many fundamental questions remain unanswered. The current study attempted to identify the APN receptor subtype responsible for APN’s vascular protective action, and investigate the role of ceramidase activation in APN anti-inflammatory signaling. Wild type (WT) or gene manipulated HUVEC were treated with TNFα in the presence and absence of APN. The effect of APN on TNFα-induced inflammatory and oxidative/nitrative stress was determined. In WT HUVEC, APN significantly reduced TNFα-induced ICAM-1 expression and attenuated TNFα-induced superoxide and peroxynitrite formation (P<0.01). These anti-inflammatory actions were virtually abolished by AdipoR1-, but not AdipoR2-, knockdown (KD). Treatment with APN significantly increased neutral ceramidase (nCDase) activity (3.7-fold, P<0.01). AdipoR1-KD markedly (P0.05), reduced APN-induced nCDase activation. More importantly, siRNA mediated nCDase-KD markedly blocked the effect of APN upon TNFα-induced ICAM-1 expression (P0.05), and modestly inhibited APN anti-inflammatory effect (P87% of APN-induced nCDase activation was lost. Whereas APN treatment failed to inhibit TNFα-induced ICAM-1 expression, treatment with S1P or SEW (S1P receptor agonist) remained effective in Cav1-KD cells in reducing TNFα-induced ICAM-1 expression (P<0.01). AdipoR1 and Cav1 co-localized and co-precipitated in HUVECs. APN treatment did not affect this interaction. Moreover, re-expression of WT Cav1 in Cav1-KD cells restored nCDase activation in response to APN (P<0.01 vs. vehicle), whereas re-expression of a mutated Cav1 blocking AdipoR1/Cav1 interaction failed to restore APN-mediated nCDase activation. Finally, there is weak basal Cav1/nCDase interaction, which significantly increased following APN treatment. These results demonstrate for the first time that APN inhibits TNFα-induced inflammatory response via Cav1-mediated ceramidase recruitment and activation in an AdipoR1- dependent fashion.


2019 ◽  
Vol 7 (1) ◽  
pp. e000817 ◽  
Author(s):  
Xiao-Qian Li ◽  
Dong-Yuan Chang ◽  
Min Chen ◽  
Ming-Hui Zhao

ObjectiveDiabetic nephropathy (DN) is the leading cause of chronic kidney disease and end-stage renal disease. Emerging evidence suggests that complement activation is involved in the pathogenesis of DN. The aim of this study was to investigate the pathogenic role of C3a and C3a receptor (C3aR) in DN.Research design and methodsThe expression of C3aR was examined in the renal specimen of patients with DN. Using a C3aR gene knockout mice (C3aR−/−), we evaluated kidney injury in diabetic mice. The mouse gene expression microarray was performed to further explore the pathogenic role of C3aR. Then the underlying mechanism was investigated in vitro with macrophage treated with C3a.ResultsCompared with normal controls, the renal expression of C3aR was significantly increased in patients with DN. C3aR−/− diabetic mice developed less severe diabetic renal damage compared with wild-type (WT) diabetic mice, exhibiting significantly lower level of albuminuria and milder renal pathological injury. Microarray profiling uncovered significantly suppressed inflammatory responses and T-cell adaptive immunity in C3aR−/− diabetic mice compared with WT diabetic mice, and this result was further verified by immunohistochemical staining of renal CD4+, CD8+ T cells and macrophage infiltration. In vitro study demonstrated C3a can enhance macrophage-secreted cytokines which could induce inflammatory responses and differentiation of T-cell lineage.ConclusionsC3aR deficiency could attenuate diabetic renal damage through suppressing inflammatory responses and T-cell adaptive immunity, possibly by influencing macrophage-secreted cytokines. Thus, C3aR may be a promising therapeutic target for DN.


Blood ◽  
2011 ◽  
Vol 118 (23) ◽  
pp. 6068-6077 ◽  
Author(s):  
Yang Wang ◽  
Mei-Feng Shen ◽  
Sandy Chang

Abstract Maintenance of mammalian telomeres requires both the enzyme telomerase and shelterin, which protect telomeres from inappropriately activating DNA damage response checkpoints. Dyskeratosis congenita is an inherited BM failure syndrome disorder because of defects in telomere maintenance. We have previously shown that deletion of the shelterin component Pot1b in the setting of telomerase haploinsufficiency results in rapid telomere shortening and fatal BM failure in mice, eliciting phenotypes that strongly resemble human syskeratosis congenita. However, it was unclear why BM failure occurred in the setting of Pot1b deletion. In this study, we show that Pot1b plays an essential role in HSC survival. Deletion of Pot1b results in increased apoptosis, leading to severe depletion of the HSC reserve. BM from Pot1bΔ/Δ mice cannot compete with BM from wild-type mice to provide multilineage reconstitution, indicating that there is an intrinsic requirement for Pot1b the maintenance of HSC function in vivo. Elimination of the p53-dependent apoptotic function increased HSC survival and significantly extended the lifespan of Pot1b-null mice deficient in telomerase function. Our results document for the first time the essential role of a component of the shelterin complex in the maintenance of HSC and progenitor cell survival.


2020 ◽  
Author(s):  
Yang Jiao ◽  
Jianjian Wang ◽  
Huixue Zhang ◽  
Yuze Cao ◽  
Yang Qu ◽  
...  

Abstract Background Microglia are rapidly activated after ischemic stroke and participate in the occurrence of neuroinflammation, which exacerbates the injury of ischemic stroke. Receptor Interacting Serine Threonine Kinase 1 (RIPK1) is thought to be involved in the development of inflammatory responses, but its role in ischemic microglia remains unclear. Here, we applied recombinant human thioredoxin-1 (rhTrx-1), a potential neuroprotective agent, to explore the role of rhTrx-1 in inhibiting RIPK1-mediated neuroinflammatory responses in microglia. Method Middle cerebral artery occlusion (MCAO) and Oxygen and glucose deprivation (OGD) were conducted for in vivo and in vitro experimental stroke models. The expression of RIPK1 in microglia after ischemia was examined. The inflammatory response of microglia was analyzed after treatment with rhTrx-1 and Necrostatin-1 (Nec-1, inhibitors of RIPK1), and the mechanisms were explored. In addition, the effects of rhTrx-1 on neurobehavioral deficits and cerebral infarct volume were examined. Results RIPK1 expression was detected in microglia after ischemia. Molecular docking results showed that rhTrx-1 could directly bind to RIPK1. In vitro experiments found that rhTrx-1 reduced necroptosis, mitochondrial membrane potential damage, Reactive oxygen species (ROS) accumulation and NLR Family, pyrin domain-containing 3 protein (NLRP3) inflammasome activation by inhibiting RIPK-1 expression, and regulated microglial M1/M2 phenotypic changes, thereby reducing the release of inflammatory factors. Consistently, in vivo experiments found that rhTrx-1 treatment attenuated cerebral ischemic injury by inhibiting the inflammatory response. Conclusion Our study demonstrates the role of RIPK1 in microglia-arranged neuroinflammation after cerebral ischemia. Administration of rhTrx-1 provides neuroprotection in ischemic stroke-induced microglial neuroinflammation by inhibiting RIPK1 expression.


Endocrinology ◽  
2021 ◽  
Author(s):  
Irena Audzeyenka ◽  
Agnieszka Bierżyńska ◽  
Abigail C Lay

Abstract Diabetic Nephropathy (DN) is the leading cause of kidney failure, with an increasing incidence worldwide. Mitochondrial dysfunction is known to occur in DN and has been implicated in the underlying pathogenesis of disease. These complex organelles have an array of important cellular functions and involvement in signalling pathways; and understanding the intricacies of these responses in health, as well as how they are damaged in disease, is likely to highlight novel therapeutic avenues. A key cell type damaged early in DN is the podocyte and increasing studies have focused on investigating the role of mitochondria in podocyte injury. This review will summarise what is known about podocyte mitochondrial dynamics in DN, with a particular focus on bioenergetic pathways, highlighting key studies in this field and potential opportunities to target, enhance or protect podocyte mitochondrial function in the treatment of DN.


2021 ◽  
Author(s):  
Upkardeep Singh Pandher ◽  
Shelley Kirychuk ◽  
David Schneberger ◽  
Brooke Thompson ◽  
Gurpreet Aulakh ◽  
...  

Abstract Background: Glyphosate is an active ingredient in herbicides used in agriculture worldwide. Exposure to glyphosate has been associated with respiratory dysfunctions in agricultural workers. However, the ability of glyphosate to induce inflammation in the lung is not well studied. Therefore, we evaluated lung inflammatory response to glyphosate at agricultural relevant dose for single and repetitive exposures. Methods: Male C57BL/6 mice were intranasally exposed to glyphosate (1 μg/40 μl) for 1-day or once daily for 5-days, and 10-days. After the exposure periods, mice were euthanized to collect the bronchoalveolar lavage (BAL) fluid and lung tissue. Results: Repetitive exposure to glyphosate for 5-days and 10-days showed an increase of neutrophils in BAL fluid and eosinophil peroxidase levels in lungs, a marker for eosinophils. Leukocyte infiltration in lungs was further confirmed through lung histology. Th2 cytokines including IL-5 and IL-13 were increased in BAL fluid after 10-days of glyphosate exposure whereas IL-4 was not increased. Lung sections from all glyphosate groups showed higher expression for ICAM-1, VCAM-1, and vWF adhesion molecules. TLR-4 and TLR-2 expression was increased in lungs after repetitive exposure to glyphosate. Conclusions: We conclude that repetitive exposure to glyphosate induces migration of neutrophils and eosinophils and release of Th2 cytokines. This study, for the first time, provides evidence for the role of ICAM-1, VCAM-1 and vWF in lungs of glyphosate-treated animals.


2020 ◽  
Vol 16 (12) ◽  
pp. e1009107
Author(s):  
M. Foulon ◽  
M. Robbe-Saule ◽  
J. Manry ◽  
L. Esnault ◽  
Y. Boucaud ◽  
...  

Mycolactone, a lipid-like toxin, is the major virulence factor of Mycobacterium ulcerans, the etiological agent of Buruli ulcer. Its involvement in lesion development has been widely described in early stages of the disease, through its cytotoxic and immunosuppressive activities, but less is known about later stages. Here, we revisit the role of mycolactone in disease outcome and provide the first demonstration of the pro-inflammatory potential of this toxin. We found that the mycolactone-containing mycobacterial extracellular vesicles produced by M. ulcerans induced the production of IL-1β, a potent pro-inflammatory cytokine, in a TLR2-dependent manner, targeting NLRP3/1 inflammasomes. We show our data to be relevant in a physiological context. The in vivo injection of these mycolactone-containing vesicles induced a strong local inflammatory response and tissue damage, which were prevented by corticosteroids. Finally, several soluble pro-inflammatory factors, including IL-1β, were detected in infected tissues from mice and Buruli ulcer patients. Our results revisit Buruli ulcer pathophysiology by providing new insight, thus paving the way for the development of new therapeutic strategies taking the pro-inflammatory potential of mycolactone into account.


2020 ◽  
Vol 21 (9) ◽  
pp. 3127 ◽  
Author(s):  
Chang-Kyu Oh ◽  
Ji Wan Kang ◽  
Yoonsung Lee ◽  
Kyungjae Myung ◽  
Mihyang Ha ◽  
...  

Relapse of acute lymphoblastic leukemia (ALL) is dangerous and it worsens the prognosis of patients; however, prognostic markers or therapeutic targets for ALL remain unknown. In the present study, using databases such as TARGET, GSE60926 and GSE28460, we determined that KIF2C and its binding partner, KIF18B are overexpressed in patients with relapsed ALL compared to that in patients diagnosed with ALL for the first time. As 50% of the residues are exactly the same and the signature domain of KIF2C is highly conserved between human and zebrafish, we used zebrafish embryos as a model to investigate the function of kif2c in vivo. We determined that kif2c is necessary for lymphopoiesis in zebrafish embryos. Additionally, we observed that kif2c is not related to differentiation of HSCs; however, it is important for the maintenance of HSCs as it provides survival signals to HSCs. These results imply that the ALL relapse-related gene KIF2C is linked to the survival of HSCs. In conclusion, we suggest that KIF2C can serve as a novel therapeutic target for relapsed ALL.


2020 ◽  
Vol 11 ◽  
Author(s):  
Liang Chang ◽  
Qi Wang ◽  
Jiannan Ju ◽  
Yue Li ◽  
Qiao Cai ◽  
...  

Diabetic nephropathy (DN) represents one of the most devastating complications for patients with diabetes. The anti-diabetic activities of Magnoflorine (MF) were reported, with underlying mechanism unknown. Lysine-specific demethylase 3A (KDM3A) was identified in the renal injuries. In the current study, we investigated the functional role of MF in DN progression with the involvement of KDM3A. We reported that in the animal model of DN induced by streptozotocin (STZ) injection, MF attenuated inflammatory response and fibrosis in the kidneys. In cultured mesangial cells, MF similarly ameliorated abnormal proliferation and lowered the expression of inflammation- and fibrosis-related factors stimulated by high glucose (HG) treatment. Upon MF treatment, there was a decline in KDM3A-positive cells in renal tissues of rats, accompanying an augment in KDM3A ubiquitination. KDM3A upregulation in vitro by a proteasome inhibitor MG132 comparably dampened the inhibitory role of MF in inflammatory response and fibrosis. Further analyses revealed that MF increased transforming growth factor β-induced factor 1 (TGIF1) transcriptional activity by promoting ubiquitination and degradation of KDM3A, thus inhibiting the activation of TGF-β1/Smad2/3 signaling pathway. TGIF1 silencing weakened the repressive role of MF in mesangial cells as well. In conclusion, MF contributes to TGIF1 transcription via an epigenetic mechanism.


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