scholarly journals NMDA receptor-mediated CaMKII/ERK activation contributes to renal fibrosis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingyi Zhou ◽  
Shuaihui Liu ◽  
Luying Guo ◽  
Rending Wang ◽  
Jianghua Chen ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Renal Fibrosis ◽  
Epithelial To Mesenchymal Transition ◽  
Ischemia Reperfusion Injury ◽  
Smooth Muscle Actin ◽  
Ischemia Reperfusion ◽  
Mesenchymal Transition ◽  
Erk Activation

Abstract Background This study aimed to understand the mechanistic role of N-methyl-D-aspartate receptor (NMDAR) in acute fibrogenesis using models of in vivo ureter obstruction and in vitro TGF-β administration. Methods Acute renal fibrosis (RF) was induced in mice by unilateral ureteral obstruction (UUO). Histological changes were observed using Masson’s trichrome staining. The expression levels of NR1, which is the functional subunit of NMDAR, and fibrotic and epithelial-to-mesenchymal transition markers were measured by immunohistochemical and Western blot analysis. HK-2 cells were incubated with TGF-β, and NMDAR antagonist MK-801 and Ca2+/calmodulin-dependent protein kinase II (CaMKII) antagonist KN-93 were administered for pathway determination. Chronic RF was introduced by sublethal ischemia–reperfusion injury in mice, and NMDAR inhibitor dextromethorphan hydrobromide (DXM) was administered orally. Results The expression of NR1 was upregulated in obstructed kidneys, while NR1 knockdown significantly reduced both interstitial volume expansion and the changes in the expression of α-smooth muscle actin, S100A4, fibronectin, COL1A1, Snail, and E-cadherin in acute RF. TGF-β1 treatment increased the elongation phenotype of HK-2 cells and the expression of membrane-located NR1 and phosphorylated CaMKII and extracellular signal–regulated kinase (ERK). MK801 and KN93 reduced CaMKII and ERK phosphorylation levels, while MK801, but not KN93, reduced the membrane NR1 signal. The levels of phosphorylated CaMKII and ERK also increased in kidneys with obstruction but were decreased by NR1 knockdown. The 4-week administration of DXM preserved renal cortex volume in kidneys with moderate ischemic–reperfusion injury. Conclusions NMDAR participates in both acute and chronic renal fibrogenesis potentially via CaMKII-induced ERK activation.

scholarly journals Hydroxychloroquine Inhibits Macrophage Activation and Attenuates Renal Fibrosis After Ischemia-Reperfusion Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Haofeng Zheng ◽  
Yannan Zhang ◽  
Jiannan He ◽  
Zhe Yang ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Renal Fibrosis ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Tubulointerstitial Fibrosis ◽  
Health Concern ◽  
Dependent Manner ◽  
Renal Tubulointerstitial Fibrosis

Chronic kidney disease (CKD), which is associated with high morbidity, remains a worldwide health concern, while effective therapies remain limited. Hydroxychloroquine (HCQ), which mainly targets toll-like receptor-7 (TLR-7) and TLR-9, is associated with a lower risk of incident CKD. Taking into account that TLR-9 is involved in the development of renal fibrosis and serves as a potential therapy target for CKD, we investigated whether HCQ could attenuate CKD via TLR-9 signal pathway. The effects of HCQ on renal tubulointerstitial fibrosis were further explored using a mouse model of renal tubulointerstitial fibrosis after ischemia/reperfusion injury. Bone marrow-derived macrophages were isolated to explore the effects of HCQ in vitro. Judicious use of HCQ efficiently inhibited the activation of macrophages and MAPK signaling pathways, thereby attenuating renal fibrosis in vivo. In an in vitro model, results showed that HCQ promoted apoptosis of macrophages and inhibited activation of macrophages, especially M2 macrophages, in a dose-dependent manner. Because TLR-7 is not involved in the development of CKD post-injury, a TLR-9 knockout mouse was used to explore the mechanisms of HCQ. The effects of HCQ on renal fibrosis and macrophages decreased after depletion of TLR-9 in vivo and in vitro. Taken together, this study indicated that proper use of HCQ could be a new strategy for anti-fibrotic therapy and that TLR-9 could be a potential therapeutic target for CKD following acute kidney injury.

scholarly journals NMDA Receptor-mediated CaMKII/ERK Activation Contributes to Renal Fibrosis

2020 ◽  
Author(s):  
Jingyi Zhou ◽  
Shuaihui Liu ◽  
Luying Guo ◽  
Rending Wang ◽  
Jianghua Chen ◽  
...  
Keyword(s):  
Western Blot ◽  
Renal Fibrosis ◽  
Ischemia Reperfusion Injury ◽  
Lentiviral Vector ◽  
Ischemia Reperfusion ◽  
Erk Activation ◽  
Function Impairment ◽  
Dependent Protein

Abstract Background: Renal fibrosis (RF) results in renal function impairment and eventually kidney failure. We found that N-methyl-D-aspartate receptor (NMDAR) played an important role during RF. However, its mechanism of action is yet to be deciphered. Methods: Acute RF was induced in mice by unilateral ureteral obstruction (UUO). NR1, which is the functional subunit of NMDAR, was downregulated using lentiviral vector-mediated shRNA interference. Histological changes were observed by Masson’s trichrome staining. Expression of NR1, fibrotic and EMT markers were measured by immunohistochemistry and western blot analysis. HK-2 cells were incubated with TGF-β, and NMDAR antagonist MK-801 and Ca2+/calmodulin-dependent protein kinase II (CaMKII) antagonist KN-93 administration were further included in this study for pathway determination. Expression of NR1, total and phosphorylated CaMKII, total and phosphorylated ERK were measured using western blot and immunofluorescent assays. Chronic renal fibrosis was introduced by sublethal ischemia-reperfusion injury in mice, and oral NMDAR inhibitor dextromethorphan (DXM) administration was performed. Results: NR1 expressions were upregulated in both obstructed kidneys and TGF-β treated HK-2 cells. NR1 knockdown, MK801 and KN93 reduced the fibrotic morphology in vivo and in vitro respectively, and companied with the downregulated ERK activation, while KN93 administration had no effect on NR1 and CaMKII levels. Mice in the DXM group had better preservation of kidney structures and corticomedullary volumes. Conclusions: NMDAR participates in both acute and chronic renal fibrogenesis via CaMKII/ERK activation, and is a potential therapeutic target for renal fibrosis.

scholarly journals Genistein Ameliorates Renal Fibrosis Through Regulation Snail via m6A RNA Demethylase ALKBH5

2020 ◽  
Vol 11 ◽  
Author(s):  
Yichun Ning ◽  
Jing Chen ◽  
Yiqin Shi ◽  
Nana Song ◽  
Xiaofang Yu ◽  
...  
Keyword(s):  
Renal Fibrosis ◽  
Epithelial To Mesenchymal Transition ◽  
Interstitial Fibrosis ◽  
Smooth Muscle Actin ◽  
Protective Action ◽  
Renal Protection ◽  
Snail Expression ◽  
Mesenchymal Transition

Renal tubule-interstitial fibrosis is related to chronic kidney disease progression and a typical feature of the aging kidney. Epigenetic modifications of fibrosis-prone genes regulate the development of renal fibrosis. As a kind of “epigenetic diet”, soy isoflavone genistein was reported to have renal protective action and epigenetic-modulating effects. However, its renal protection role and underlying mechanisms are yet to be fully clarified. Herein, we showed that genistein exhibits a demonstrable anti-fibrotic effect on kidney in vivo UUO (unilateral ureteral occlusion) model and renal epithelial cells in vitro model. The mechanism is strongly associated with epithelial-to-mesenchymal transition and m6A RNA demethylase ALKBH5. Mouse fibrotic kidneys induced by UUO exhibited adverse expression of renal fibrosis-related proteins and significant increases in the total m6A level. As an eraser, ALKBH5 showed severer suppression in the renal fibrosis process. However, genistein pretreatment restored ALKBH5 loss remarkably and reduced renal fibrosis, abnormal protein, and inflammatory markers. The examination of possible mechanisms revealed that genistein promoted ALKBH5 and maybe induced the level of mRNA m6A methylation in some epithelial-to-mesenchymal transition-related transcription factors. We found snail was the critical regulator and critical for the protective role of genistein. To verify the relationship between ALKBH5 and snail, we generated knockdown and overexpression of ALKBH5 cells in vitro. ALKBH5 knockdown enhanced the mesenchymal phenotype marker α-smooth muscle actin and snail expression. In agreement, overexpression ALKBH5 increased epithelial adhesion molecule E-cadherin and reduced snail expression. In conclusion, genistein increased renal ALKBH5 expression in UUO-induced renal fibrosis and reduced RNA m6A levels and ameliorates renal damages.

scholarly journals NMDA Receptor-mediated CaMKII/ERK Activation Contributes to Renal Fibrosis

2020 ◽  
Author(s):  
Jingyi Zhou ◽  
Shuaihui Liu ◽  
Luying Guo ◽  
Rending Wang ◽  
Jianghua Chen ◽  
...  
Keyword(s):  
Western Blot ◽  
Renal Fibrosis ◽  
Ischemia Reperfusion Injury ◽  
Lentiviral Vector ◽  
Ischemia Reperfusion ◽  
Erk Activation ◽  
Function Impairment ◽  
Dependent Protein

Abstract Background: Renal fibrosis (RF) results in renal function impairment and eventually kidney failure. We found that N-methyl-D-aspartate receptor (NMDAR) played an important role during RF. However, its mechanism of action is yet to be deciphered. Methods: Acute RF was induced in mice by unilateral ureteral obstruction (UUO). NR1, which is the functional subunit of NMDAR, was downregulated using lentiviral vector-mediated shRNA interference. Histological changes were observed by Masson’s trichrome staining. Expression of NR1, fibrotic and EMT markers were measured by immunohistochemistry and western blot analysis. HK-2 cells were incubated with TGF-β, and NMDAR antagonist MK-801 and Ca2+/calmodulin-dependent protein kinase II (CaMKII) antagonist KN-93 administration were further included in this study for pathway determination. Expression of NR1, total and phosphorylated CaMKII, total and phosphorylated ERK were measured using western blot and immunofluorescent assays. Chronic renal fibrosis was introduced by sublethal ischemia-reperfusion injury in mice, and oral NMDAR inhibitor dextromethorphan (DXM) administration was performed. Results: NR1 expressions were upregulated in both obstructed kidneys and TGF-β treated HK-2 cells. NR1 knockdown, DXM, MK801, and KN93 reduced the fibrotic morphology in vivo and in vitro respectively, and companied with the downregulated ERK activation, while KN93 administration had no effect on NR1 and CaMKII levels. Conclusions: NMDAR participates in both acute and chronic renal fibrogenesis via CaMKII/ERK activation, and is a potential therapeutic target for renal fibrosis.

scholarly journals N6-methyladenosine demethylase FTO impairs hepatic ischemia–reperfusion injury via inhibiting Drp1-mediated mitochondrial fragmentation

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Ying Dong Du ◽  
Wen Yuan Guo ◽  
Cong Hui Han ◽  
Ying Wang ◽  
Xiao Song Chen ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fragmentation ◽  
Hepatic Ischemia ◽  
Adeno Associated Virus ◽  
Downstream Target ◽  
Hepatic Ischemia Reperfusion

AbstractDespite N6-methyladenosine (m6A) is functionally important in various biological processes, its role and the underlying regulatory mechanism in the liver remain largely unexplored. In the present study, we showed that fat mass and obesity-associated protein (FTO, an m6A demethylase) was involved in mitochondrial function during hepatic ischemia–reperfusion injury (HIRI). We found that the expression of m6A demethylase FTO was decreased during HIRI. In contrast, the level of m6A methylated RNA was enhanced. Adeno-associated virus-mediated liver-specific overexpression of FTO (AAV8-TBG-FTO) ameliorated the HIRI, repressed the elevated level of m6A methylated RNA, and alleviated liver oxidative stress and mitochondrial fragmentation in vivo and in vitro. Moreover, dynamin-related protein 1 (Drp1) was a downstream target of FTO in the progression of HIRI. FTO contributed to the hepatic protective effect via demethylating the mRNA of Drp1 and impairing the Drp1-mediated mitochondrial fragmentation. Collectively, our findings demonstrated the functional importance of FTO-dependent hepatic m6A methylation during HIRI and provided valuable insights into the therapeutic mechanisms of FTO.

In vivo and In vitro PPAR-y Activation Decreases M1-Macrophage Polarization and Improves Liver Ischemia Reperfusion Injury

2018 ◽  
Vol 102 ◽  
pp. S708
Author(s):  
Ivan Linares ◽  
Agata Bartczak ◽  
Kaveh Farrokhi ◽  
Dagmar Kollmann ◽  
Moritz Kaths ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Macrophage Polarization ◽  
Liver Ischemia ◽  
M1 Macrophage

scholarly journals Poly-IC Preconditioning Protects against Cerebral and Renal Ischemia-Reperfusion Injury

2011 ◽  
Vol 32 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Amy E B Packard ◽  
Jason C Hedges ◽  
Frances R Bahjat ◽  
Susan L Stevens ◽  
Michael J Conlin ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Cortical Cells ◽  
Polycytidylic Acid ◽  
Populations At Risk

Preconditioning induces ischemic tolerance, which confers robust protection against ischemic damage. We show marked protection with polyinosinic polycytidylic acid (poly-IC) preconditioning in three models of murine ischemia-reperfusion injury. Poly-IC preconditioning induced protection against ischemia modeled in vitro in brain cortical cells and in vivo in models of brain ischemia and renal ischemia. Further, unlike other Toll-like receptor (TLR) ligands, which generally induce significant inflammatory responses, poly-IC elicits only modest systemic inflammation. Results show that poly-IC is a new powerful prophylactic treatment that offers promise as a clinical therapeutic strategy to minimize damage in patient populations at risk of ischemic injury.

scholarly journals Transplantation-Induced Ischemia-Reperfusion Injury Modulates Antigen Presentation by Donor Renal CD11c+F4/80+ Macrophages through IL-1R8 Regulation

2020 ◽  
Vol 31 (3) ◽  
pp. 517-531 ◽  
Author(s):  
Sistiana Aiello ◽  
Manuel Alfredo Podestà ◽  
Pamela Y. Rodriguez-Ordonez ◽  
Francesca Pezzuto ◽  
Nadia Azzollini ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Antigen Presentation ◽  
Kidney Transplant ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cold Ischemia ◽  
Reversible Ischemia ◽  
Antigen Presenting

BackgroundIn donor kidneys subjected to ischemia-reperfusion injury during kidney transplant, phagocytes coexpressing the F4/80 and CD11c molecules mediate proinflammatory responses and trigger adaptive immunity in transplantation through antigen presentation. After injury, however, resident renal macrophages coexpressing these surface markers acquire a proreparative phenotype, which is pivotal in controlling inflammation and fibrosis. No data are currently available regarding the effects of transplant-induced ischemia-reperfusion injury on the ability of donor-derived resident renal macrophages to act as professional antigen-presenting cells.MethodsWe evaluated the phenotype and function of intragraft CD11c+F4/80+ renal macrophages after cold ischemia. We also assessed the modifications of donor renal macrophages after reversible ischemia-reperfusion injury in a mouse model of congeneic renal transplantation. To investigate the role played by IL-1R8, we conducted in vitro and in vivo studies comparing cells and grafts from wild-type and IL-R8–deficient donors.ResultsCold ischemia and reversible ischemia-reperfusion injury dampened antigen presentation by renal macrophages, skewed their polarization toward the M2 phenotype, and increased surface expression of IL-1R8, diminishing activation mediated by toll-like receptor 4. Ischemic IL-1R8–deficient donor renal macrophages acquired an M1 phenotype, effectively induced IFNγ and IL-17 responses, and failed to orchestrate tissue repair, resulting in severe graft fibrosis and aberrant humoral immune responses.ConclusionsIL-1R8 is a key regulator of donor renal macrophage functions after ischemia-reperfusion injury, crucial to guiding the phenotype and antigen-presenting role of these cells. It may therefore represent an intriguing pathway to explore with respect to modulating responses against autoantigens and alloantigens after kidney transplant.

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