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 ◽  
...  

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.

2020 ◽  
Author(s):  
Jingyi Zhou ◽  
Shuaihui Liu ◽  
Luying Guo ◽  
Rending Wang ◽  
Jianghua Chen ◽  
...  

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.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingyi Zhou ◽  
Shuaihui Liu ◽  
Luying Guo ◽  
Rending Wang ◽  
Jianghua Chen ◽  
...  

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.


2019 ◽  
Author(s):  
Jingyi Zhou ◽  
Shuaihui Liu ◽  
Luying Guo ◽  
Rending Wang ◽  
Jianghua Chen ◽  
...  

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: RF was induced in vivo by unilateral ureteral obstruction (UUO) using 8-week-old C57BL/6 mice. The expression levels of the NMDAR’s functional subunit, NR1, was downregulated using lentiviral vector-mediated shRNA interference. Histological changes were observed using Masson’s trichrome staining. Expression of NR1, fibrotic markers (α-smooth muscle actin (α-SMA), type I collagen (COL1A4), S100A4 and fibronectin), and EMT markers (snail and E-cadherin) were measured using immunohistochemistry and western blot analysis. RF was induced after TGF-β-treatment in HK-2 cells in vitro. NMDAR antagonist MK-801 and Ca2+/calmodulin-dependent protein kinase II (CaMKII) antagonist KN-93 were included in this study for pathway determination. Expression of NR1, total and phosphorylation of CaMKII (p-CaMKII), total and p-ERK were measured using western blot and immunofluorescent assays. Results from in vitro studies were confirmed using in vivo studies for NR1, CaMKII and ERK expression levels. In addition, ischemia-reperfusion injury (IRI) mouse model was used to determine whether oral NMDAR inhibitor dextromethorphan (DXM) could inhibit chronic fibrosis. Results: Increased NR1 expression was observed in both UUO-injured kidneys and TGF-β-treated tubular cells. NR1 knockdown and MK801 administration downregulated CaMKII/ERK activation. In vitro administered CaMKII antagonist KN93 reduced ERK phosphorylation and was not affected by NR1 expression levels. DXM protected IRI-injured kidneys from atrophy and fibrosis. Conclusions: NMDAR participates in renal fibrogenesis by activating the CaMKII/ERK pathway. NMDAR could be a potential therapeutic target for renal fibrosis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haofeng Zheng ◽  
Yannan Zhang ◽  
Jiannan He ◽  
Zhe Yang ◽  
Rui Zhang ◽  
...  

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.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Ying Dong Du ◽  
Wen Yuan Guo ◽  
Cong Hui Han ◽  
Ying Wang ◽  
Xiao Song Chen ◽  
...  

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.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Jian-Ping Zhang ◽  
Wei-Jing Zhang ◽  
Miao Yang ◽  
Hua Fang

Abstract Background Propofol, an intravenous anesthetic, was proven to protect against lung ischemia/reperfusion (I/R) injury. However, the detailed mechanism of Propofol in lung I/R injury is still elusive. This study was designed to explore the therapeutic effects of Propofol, both in vivo and in vitro, on lung I/R injury and the underlying mechanisms related to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-144 (miR-144)/glycogen synthase kinase-3β (GSK3β). Methods C57BL/6 mice were used to establish a lung I/R injury model while pulmonary microvascular endothelial cells (PMVECs) were constructed as hypoxia/reperfusion (H/R) cellular model, both of which were performed with Propofol treatment. Gain- or loss-of-function approaches were subsequently employed, followed by observation of cell apoptosis in lung tissues and evaluation of proliferative and apoptotic capabilities in H/R cells. Meanwhile, the inflammatory factors, autophagosomes, and autophagy-related proteins were measured. Results Our experimental data revealed that Propofol treatment could decrease the elevated expression of MALAT1 following I/R injury or H/R induction, indicating its protection against lung I/R injury. Additionally, overexpressing MALAT1 or GSK3β promoted the activation of autophagosomes, proinflammatory factor release, and cell apoptosis, suggesting that overexpressing MALAT1 or GSK3β may reverse the protective effects of Propofol against lung I/R injury. MALAT1 was identified to negatively regulate miR-144 to upregulate the GSK3β expression. Conclusion Overall, our study demonstrated that Propofol played a protective role in lung I/R injury by suppressing autophagy and decreasing release of inflammatory factors, with the possible involvement of the MALAT1/miR-144/GSK3β axis.


Human Cell ◽  
2021 ◽  
Author(s):  
Jiaying Zhu ◽  
Zhu Zhu ◽  
Yipin Ren ◽  
Yukang Dong ◽  
Yaqi Li ◽  
...  

AbstractLINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, middle cerebral artery occlusion/reperfusion (MACO/R) mice model and HT22 cell oxygen–glucose deprivation/reperfusion (OGD/R) were established to simulate the pathological process of cerebral ischemia in vivo and in vitro and to detect the relevant mechanism. We found that LINGO-1 mRNA and protein were upregulated in mice and cell models. Down-regulation LINGO-1 improved the neurological symptoms and reduced pathological changes and the infarct size of the mice after MACO/R. In addition, LINGO-1 interference alleviated apoptosis and promoted cell proliferation in HT22 of OGD/R. Moreover, down-regulation of LINGO-1 proved to inhibit nuclear translocation of p-NF-κB and reduce the expression level of p-JAK2 and p-STAT3. In conclusion, our data suggest that shLINGO-1 attenuated ischemic injury by negatively regulating NF-KB and JAK2/STAT3 pathways, highlighting a novel therapeutic target for ischemic stroke.


2021 ◽  
Vol 22 (5) ◽  
pp. 2727
Author(s):  
Gertrude J. Nieuwenhuijs-Moeke ◽  
Dirk J. Bosch ◽  
Henri G.D. Leuvenink

Ischemia reperfusion injury (IRI) is inevitable in kidney transplantation and negatively impacts graft and patient outcome. Reperfusion takes place in the recipient and most of the injury following ischemia and reperfusion occurs during this reperfusion phase; therefore, the intra-operative period seems an attractive window of opportunity to modulate IRI and improve short- and potentially long-term graft outcome. Commonly used volatile anesthetics such as sevoflurane and isoflurane have been shown to interfere with many of the pathophysiological processes involved in the injurious cascade of IRI. Therefore, volatile anesthetic (VA) agents might be the preferred anesthetics used during the transplantation procedure. This review highlights the molecular and cellular protective points of engagement of VA shown in in vitro studies and in vivo animal experiments, and the potential translation of these results to the clinical setting of kidney transplantation.


2018 ◽  
Vol 102 ◽  
pp. S708
Author(s):  
Ivan Linares ◽  
Agata Bartczak ◽  
Kaveh Farrokhi ◽  
Dagmar Kollmann ◽  
Moritz Kaths ◽  
...  

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