scholarly journals METTL14 promotes glomerular endothelial cell injury and diabetic nephropathy via m6A modification of α-klotho

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Manna Li ◽  
Le Deng ◽  
Gaosi Xu

Abstract Background N6-Methyladenosine (m6A) modification has been implicated in many bioprocesses. However, its functions in diabetic nephropathy (DN) have not been determined. Here, we investigated the role of METTL14, a key component of the m6A methyltransferase complex, in DN. Methods The expression of METTL14 was detected in DN patients and human renal glomerular endothelial cells (HRGECs). In vitro and in vivo experiments were performed to explore the functions of METTL14 on high glocse-induced HRGECs and renal injury of DN mice. We also investigated whether METTL14 works by regulating α-klotho expression through m6A modification. Results METTL14 were highly expressed in kidneys of DN patients and high glocse-induced HRGECs both at the mRNA and protein level. Overexpression of METTL14 increased ROS, TNF-α and IL-6 levels and apoptosis in HRGECs. Conversely, METTL14 silence decreased the levels of ROS, TNF-α and IL-6 and cell apoptosis. We confirmed that METTL14 down-regulated α-klotho expression in an m6A-dependent manner. In addition, we also found that METTL14 aggravated renal injury and inflammation of db/db mice, which could partially rescued by α-klotho. Conclusion Our data revealed that METTL14 plays a vital role in high glucose-induced glomerular endothelial cells and diabetic nephropathy through m6A modification of α-klotho.

2001 ◽  
Vol 281 (4) ◽  
pp. C1096-C1105 ◽  
Author(s):  
Tadayuki Oshima ◽  
Kevin P. Pavlick ◽  
F. Stephen Laroux ◽  
S. Kris Verma ◽  
Paul Jordan ◽  
...  

Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is a 60-kDa endothelial cell adhesion glycoprotein that regulates lymphocyte trafficking to Peyer's patches and lymph nodes. Although it is widely agreed that MAdCAM-1 induction is involved in chronic gut inflammation, few studies have investigated regulation of MAdCAM-1 expression. We used two endothelial lines [bEND.3 (brain) and SVEC (high endothelium)] to study the signal paths that regulate MAdCAM-1 expression in response to tumor necrosis factor (TNF)-α using RT-PCR, blotting, adhesion, and immunofluorescence. TNF-α induced both MAdCAM-1 mRNA and protein in a dose- and time-dependent manner. This induction was tyrosine kinase (TK), p42/44, p38 mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB/poly-ADP ribose polymerase (PARP) dependent. Because MAdCAM-1 is regulated via MAPKs, we examined mitogen/extracellular signal-regulated kinase (MEK)-1/2 activation in SVEC. We found that MEK-1/2 is activated by TNF-α within minutes and is dependent on TK and p42/44 MAPKs. Similarly, TNF-α activated NF-κB through TK, p42/44, p38 MAPKs, and PARP pathways in SVEC cells. MAdCAM-1 was also shown to be frequently distributed to endothelial junctions both in vitro and in vivo. Cytokines like TNF-α stimulate MAdCAM-1 in high endothelium via TK, p38, p42/22 MAPKs, and NF-κB/PARP. MAdCAM-1 expression requires NF-κB translocation through both direct p42/44 and indirect p38 MAPK pathways in high endothelial cells.


2019 ◽  
Vol 20 (2) ◽  
pp. 405
Author(s):  
Erwei Hao ◽  
Guofeng Pang ◽  
Zhengcai Du ◽  
Yu-Heng Lai ◽  
Jung-Ren Chen ◽  
...  

Atherosclerosis is the pathological process in arteries due to the plaque formation that is responsible for several diseases like heart disease, stroke and peripheral arterial disease. In this study, we performed in vitro and in vivo assays to evaluate the potential anti-atherosclerosis activity of peach kernel oil. For the in vitro assay, we incubated human umbilical vein endothelial cells (HUVEC) with tumor necrosis factor-α (TNF-α) to induce tissue factors (TF, an essential mediator of hemostasis and trigger of thrombosis) elevation. We found that TNF-α-induced TF elevation was suppressed by peach kernel oil in a dose-dependent manner at both mRNA and protein levels. Peach kernel oil can significantly improve HUVEC viability, protect the endothelial cells, which achieved the goal of prevention of thrombotic diseases. For the in vivo assay, we investigated the effect and mechanism of peach kernel oil on preventing atherosclerotic lesion formation in ApoE knockout mice. Results show that peach kernel oil could reduce total cholesterol, triglyceride, low-density lipoprotein cholesterol levels, elevate the high-density lipoprotein cholesterol level in serum, and reduce the area of the aortic atherosclerotic lesions in high-fat diet fed ApoE knockout mice. Moreover, peach kernel oil treatment can significantly down regulate the expression of TF protein to inhibit the formation of atherosclerotic plaque. In conclusion, peach kernel oil may be a potential health food to prevent atherosclerosis in cardiovascular diseases.


Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Natalia K. Kordulewska ◽  
Justyna Topa ◽  
Małgorzata Tańska ◽  
Anna Cieślińska ◽  
Ewa Fiedorowicz ◽  
...  

Lipopolysaccharydes (LPS) are responsible for the intestinal inflammatory reaction, as they may disrupt tight junctions and induce cytokines (CKs) secretion. Osthole has a wide spectrum of pharmacological effects, thus its anti-inflammatory potential in the LPS-treated Caco-2 cell line as well as in Caco-2/THP-1 and Caco-2/macrophages co-cultures was investigated. In brief, Caco-2 cells and co-cultures were incubated with LPS to induce an inflammatory reaction, after which osthole (150–450 ng/mL) was applied to reduce this effect. After 24 h, the level of secreted CKs and changes in gene expression were examined. LPS significantly increased the levels of IL-1β, -6, -8, and TNF-α, while osthole reduced this effect in a concentration-dependent manner, with the most significant decrease when a 450 ng/mL dose was applied (p < 0.0001). A similar trend was observed in changes in gene expression, with the significant osthole efficiency at a concentration of 450 ng/μL for IL1R1 and COX-2 (p < 0.01) and 300 ng/μL for NF-κB (p < 0.001). Osthole increased Caco-2 monolayer permeability, thus if it would ever be considered as a potential drug for minimizing intestinal inflammatory symptoms, its safety should be confirmed in extended in vitro and in vivo studies.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.


2017 ◽  
Vol 43 (5) ◽  
pp. 2074-2087 ◽  
Author(s):  
Liling Yang ◽  
Xiangjun Zhou ◽  
Weijuan Huang ◽  
Qin Fang ◽  
Jianlan Hu ◽  
...  

Background/Aims: Forsythia suspensa Vahl. (Oleaceae) fruits are widely used in traditional Chinese medicine to treat pneumonia, typhoid, dysentery, ulcers and oedema. Antibacterial and anti-inflammatory activities have been reported for phillyrin (PHN), the main ingredient in Forsythia suspensa Vahl fruits, in vitro. However, the underlying mechanisms in vivo remain poorly defined. In this study, we discovered that PHN exerted potent anti-inflammatory effects in lethal LPS-induced neutrophil inflammation by suppressing the MyD88-dependent signalling pathway in zebrafish. Methods: LPS-yolk microinjection was used to induce a lethal LPS-infected zebrafish model. The effect of PHN on the survival of zebrafish challenged with lethal LPS was evaluated using survival analysis. The effect of PHN on neutrophil inflammation grading in vivo was assessed by tracking neutrophils with a transgenic line. The effects of PHN on neutrophil production and migration were analysed by SB+ cell counts during consecutive hours after modelling. Additionally, key cytokines and members of the MyD88 signalling pathway that are involved in inflammatory response were detected using quantitative RT-PCR. To assess gene expression changes during consecutive hours after modelling, the IL-1β, IL-6, TNF-α, MyD88, TRIF, ERK1/2, JNK, IκBa and NF-κB expression levels were measured. Results: PHN could protect zebrafish against a lethal LPS challenge in a dose-dependent manner, as indicated by decreased neutrophil infltration, reduced tissue necrosis and increased survival rates. Up-regulated IL-1β, IL-6 and TNF-α expression also showed the same tendencies of depression by PHN. Critically, PHN significantly inhibited the LPS-induced activation of MyD88, IκBa, and NF-κB but did not affect the expression of ERK1/2 MAPKs or JNK MAPKs in LPS-stimulated zebrafish. Additionally, PHN regulated the MyD88/IκBα/NF-κB signalling pathway by controlling IκBα, IL-1β, IL-6, and TNF-α expression. Conclusion: This study provides a rationale for the clinical application of PHN as an anti-inflammatory agent.


2020 ◽  
Author(s):  
Chuan-jiang Liu ◽  
Qiang Fu ◽  
Wenjing Zhou ◽  
Xu Zhang ◽  
Rui Chen ◽  
...  

Abstract Background: Methylprednisolone (MP) is a synthetic corticosteroid with potent anti-inflammatory and antioxidant properties used as therapy for a variety of diseases. The underlying mechanism of MP to reduce acute pancreatitis still needs to be elucidated.Methods: Twenty-four male C57BL/6 mice (6-8 weeks) were used to establish SAP mouse model by administering an intraperitoneal injection of Cae and LPS. Amylase expression levels of serum and PLF were measured with an amylase assay kit. The concentrations of IL-1β and TNF-α in the serum and PLF were detected by ELISA. The level of pancreatic and lung tissue damage and inflammation was assessed by H&E staining and immunofluorescence staining. Western blot and qPCR were used to detect the expression levels of NLRP3, IL-1β and TNF-αin vivo and in vitro.Results: In this study, we found MP, used in the early phase of SAP, decreased the levels of IL-1β and TNF-α in serum and peritoneal lavage fluids (PLF), reduced the level of serum amylase and the expression of MPO in lung tissue, attenuated the pathological injury of the pancreas and lungs in a dose-dependent manner. The expression of NLRP3 and IL-1β in pancreas and lungs was down-regulated significantly depending on the MP concentration. In vitro, MP reduced the levels of IL-1β and TNF-α by down-regulating the expression of NLRP3, IL-1β and p-NF-κB in isolated peritoneal macrophages. Conclusion: MP can attenuate the injury of pancreas and lungs, and the inflammatory response in SAP mice by down-regulating the activation of NF-κB and the NLRP3 inflammasome.


Blood ◽  
1997 ◽  
Vol 89 (9) ◽  
pp. 3228-3235 ◽  
Author(s):  
A. Zakrzewicz ◽  
M. Gräfe ◽  
D. Terbeek ◽  
M. Bongrazio ◽  
W. Auch-Schwelk ◽  
...  

Abstract To characterize L-selectin–dependent cell adhesion to human vascular endothelium, human cardiac microvascular endothelial cells (HCMEC) and human coronary endothelial cells (HCEC) were isolated from explanted human hearts. The adhesion behavior of human (NALM-6) and mouse (300.19) pre-B cells transfected with cDNA encoding for human L-selectin was compared with that of the respective nontransfected cells in a flow chamber in vitro. More than 80% of the adhesion to tumor necrosis factor-α (TNF-α)–stimulated HCMEC at shear stresses <2 dyne/cm2 was L-selectin dependent and could be equally well blocked by an anti–L-selectin antibody or a L-selectin-IgG-chimera. No L-selectin dependent adhesion to HCEC could be shown. The L-selectin dependent adhesion to HCMEC was insensitive to neuraminidase, but greatly inhibited by addition of NaClO3 , which inhibits posttranslational sulfation and remained elevated for at least 24 hours of stimulation. E-selectin dependent adhesion of HL60 cells to HCMEC was blocked by neuraminidase, but not by NaClO3 and returned to control levels within 18 hours of HCMEC stimulation. It is concluded that microvascular, but not macrovascular endothelial cells express TNF-α–inducible sulfated ligand(s) for L-selectin, which differ from known L-selectin ligands, because sialylation is not required. The prolonged time course of L-selectin dependent adhesion suggests a role in sustained leukocyte recruitment into inflammatory sites in vivo.


2021 ◽  
Author(s):  
Xia Wang ◽  
Yinhua Wang ◽  
Guo Zhou ◽  
Yi Li ◽  
Huanhuan Huo ◽  
...  

Abstract Background Sepsis-associated acute kidney injury (S-AKI) is a frequent complication of critical patients and is associated with high morbidity and mortality. The glomerular endothelial cell injury is the main characteristics during S-AKI. Ca2+ influx is a key step in the establishment of endothelial injury. Transient receptor vanilloid subtype 4 (TRPV4) ion channels are permeable to Ca2+ and are widely expressed in endothelial cells. However, the role of TRPV4 on glomerular endothelial inflammation in S-AKI has remained elusive. Methods Mouse glomerular endothelial cells (MRGEC) were used to test the molecular mechanism of TRPV4 on LPS-induced glomerular endothelial inflammation. The cecal-ligation-and-puncture (CLP) model was established by ligation of cecum with 4-0 suture and punctured with a 21-gauge needle. Then 0.2mL faeces was extruded from the puncture site to trigger peritoneal inflammation. Results In the present study, we found that blocking TRPV4 diminishes LPS-induced cytosolic Ca2+-elevations, which are essential for glomerular endothelial inflammation and barrier function. Furthermore, TRPV4 regulated LPS-induced phosphorylation and translocation of NF-κB and IRF-3 in mouse glomerular endothelial cells (MRGEC). Clamping intracellular Ca2+ mimics the LPS-induce response seen in the absence of TRPV4. In vivo, pharmacological blockade or knock down of TRPV4 reduced the inflammatory response of glomerular endothelial cells, inhibited translocation of NF-κB and IRF-3, increased survival rate and improved renal function in CLP-induced sepsis but without altering renal cortical blood perfusion. Conclusions Taken together, these results suggested that inhibition of TRPV4 ameliorates glomerular endothelial inflammation, kidney dysfunction, and increased mortality via mediating Ca2+ overload and NF-κB/IRF-3 activation. These discoveries may provide novel pharmacological strategies for the treatment of glomerular endothelial dysfunction and kidney injury during endotoxemia, sepsis, and other inflammatory diseases.


2018 ◽  
Vol 115 (15) ◽  
pp. 3930-3935 ◽  
Author(s):  
Dongshi Chen ◽  
Jingshan Tong ◽  
Liheng Yang ◽  
Liang Wei ◽  
Donna B. Stolz ◽  
...  

Necroptosis, a form of regulated necrotic cell death, is governed by RIP1/RIP3-mediated activation of MLKL. However, the signaling process leading to necroptotic death remains to be elucidated. In this study, we found that PUMA, a proapoptotic BH3-only Bcl-2 family member, is transcriptionally activated in an RIP3/MLKL-dependent manner following induction of necroptosis. The induction of PUMA, which is mediated by autocrine TNF-α and enhanced NF-κB activity, contributes to necroptotic death in RIP3-expressing cells with caspases inhibited. On induction, PUMA promotes the cytosolic release of mitochondrial DNA and activation of the DNA sensors DAI/Zbp1 and STING, leading to enhanced RIP3 and MLKL phosphorylation in a positive feedback loop. Furthermore, deletion of PUMA partially rescues necroptosis-mediated developmental defects in FADD-deficient embryos. Collectively, our results reveal a signal amplification mechanism mediated by PUMA and cytosolic DNA sensors that is involved in TNF-driven necroptotic death in vitro and in vivo.


2006 ◽  
Vol 19 (1) ◽  
pp. 205873920601900 ◽  
Author(s):  
M. Bongrazio ◽  
L. DA Silva-Azevedo ◽  
E.C. Bergmann ◽  
O. Baum ◽  
B. Hinz ◽  
...  

Binding of thrombospondin-1 (TSP-1) to the CD36 receptor inhibits angiogenesis and induces apoptosis in endothelial cells (EC). Conversely, matrix-bound TSP-1 supports vessel formation. In this study we analyzed the shear stress-dependent expression of TSP-1 and CD36 in endothelial cells in vitro and in vivo to reveal its putative role in the blood flow-induced remodelling of vascular networks. Shear stress was applied to EC using a cone-and-plate apparatus and gene expression was analyzed by RT-PCR, Northern and Western blot. Angiogenesis in skeletal muscles of prazosin-fed (50 mg/1 drinking water; 4 d) mice was assessed by measuring capillary-to-fiber (C/F) ratios. Protein expression in whole muscle homogenates (WMH) or BS-1 lectin-enriched EC fractions (ECF) was analyzed by Western blot. Shear stress down-regulated TSP-1 and CD36 expression in vitro in a force- and time-dependent manner sustained for at least 72 h and reversible by restoration of no-flow conditions. In vivo, shear stress-driven increase of C/F in prazosin-fed mice was associated with reduced expression of TSP-1 and CD36 in ECF, while TSP-1 expression in WMH was increased. Down-regulation of endothelial TSP-1/CD36 by shear stress suggests a mechanism for inhibition of apoptosis in perfused vessels and pruning in the absence of flow. The increase of extra-endothelial (e.g. matrix-bound) TSP-1 could support a splitting type of vessel growth.


Sign in / Sign up

Export Citation Format

Share Document