scholarly journals DsbA-L deficiency exacerbates mitochondrial dysfunction of tubular cells in diabetic kidney disease

2020 ◽  
Vol 134 (7) ◽  
pp. 677-694
Author(s):  
Peng Gao ◽  
Ming Yang ◽  
Xianghui Chen ◽  
Shan Xiong ◽  
Jiahao Liu ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Diabetic Kidney Disease ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Mrna Levels ◽  
Mitochondrial Fragmentation ◽  
Diabetic Kidney ◽  
Tubular Cells ◽  
Gene And Protein Expression

Abstract Excessive mitochondrial fission has been identified as the central pathogenesis of diabetic kidney disease (DKD), but the precise mechanisms remain unclear. Disulfide-bond A oxidoreductase-like protein (DsbA-L) is highly expressed in mitochondria in tubular cells of the kidney, but its pathophysiological role in DKD is unknown. Our bioinformatics analysis showed that tubular DsbA-L mRNA levels were positively associated with eGFR but negatively associated with Scr and 24h-proteinuria in CKD patients. Furthermore, the genes that were coexpressed with DsbA-L were mainly enriched in mitochondria and were involved in oxidative phosphorylation. In vivo, knockout of DsbA-L exacerbated diabetic mice tubular cell mitochondrial fragmentation, oxidative stress and renal damage. In vitro, we found that DsbA-L was localized in the mitochondria of HK-2 cells. High glucose (HG, 30 mM) treatment decreased DsbA-L expression followed by increased mitochondrial ROS (mtROS) generation and mitochondrial fragmentation. In addition, DsbA-L knockdown exacerbated these abnormalities, but this effect was reversed by overexpression of DsbA-L. Mechanistically, under HG conditions, knockdown DsbA-L expression accentuated JNK phosphorylation in HK-2 cells. Furthermore, administration of a JNK inhibitor (SP600125) or the mtROS scavenger MitoQ significantly attenuated JNK activation and subsequent mitochondrial fragmentation in DsbA-L-knockdown HK-2 cells. Additionally, the down-regulation of DsbA-L also amplified the gene and protein expression of mitochondrial fission factor (MFF) via the JNK pathway, enhancing its ability to recruit DRP1 to mitochondria. Taken together, these results link DsbA-L to alterations in mitochondrial dynamics during tubular injury in the pathogenesis of DKD and unveil a novel mechanism by which DsbA-L modifies mtROS/JNK/MFF-related mitochondrial fission.

P0996THE INVOLVEMENT OF PRO-INFLAMMATORY IL-1 CYTOKINES IN TUBULAR INJURY IN DIABETIC KIDNEY DISEASE

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Vladislav Slobodsky ◽  
Adi Litmanovich ◽  
Kamal Hassan ◽  
Khaled Khazim
Keyword(s):  
Kidney Disease ◽  
Protein Expression ◽  
Western Blotting ◽  
High Glucose ◽  
Diabetic Kidney Disease ◽  
Diabetic Patients ◽  
Mrna Levels ◽  
Diabetic Kidney ◽  
Tubular Cells ◽  
Fibronectin Expression

Abstract Background and Aims Pro-inflammatory cytokines are one of several factors which contribute to the progression of diabetic kidney disease (DKD), a condition characterized by chronic kidney inflammation which results in the tubulointerstitial fibrosis which contributes to the progression of DKD. Interleukin 1 (IL-1) two main agonists IL-1α and IL-1β activate a pro-inflammatory cascade in response to different inflammatory stimuli, including hyperglycemia. It was previously shown that a deficiency of NLRP3 which is required for the conversion of IL-1 to its active state, protects mice from the development and progression of DKD. We hypothesize that the chronic hyperglycemia in diabetic patients triggers the activation and release of IL1α and/or IL-1β from renal tubular cells and that this activation leads to the tissue fibrosis. We aim to assess Il-1 and fibronectin expression in an immortalized proximal tubule epithelial cell line from normal adult human kidney (HK-2). In addition, we evaluate the influence of Anakinra™, a pharmaceutical inhibitor of the Il-1 receptor, currently indicated mainly for rheumatoid diseases, on the levels of fibronectin expression in this model. Methods HK-2 cells were cultured and treated with either physiological glucose concentration (5.5mM), high glucose (30mM) or 30mM mannitol as osmotic control for 24 hours to evaluate their effects on Il-1 expression and fibronectin expression. mRNA levels of IL-1α, IL-1β and fibronectin were assessed in q-PCR, and protein expression levels were quantified by western blotting. Immunofluorescence was used to visually demonstrate the presence of IL-1α and IL-1β upon stimulation. Finally, Anakinra™ was added to the tissue cultures in a range of physiologic prescribed concentrations and its effect on cell fibrosis was assessed by the measurement of fibronectin expression 24 hours later by western blotting. Results mRNA and protein expression of IL-1α but mostly IL-1β was elevated in HK-2 cells under hyperglycemic conditions but not in physiological glucose environment or under high osmotic conditions. Fibronectin levels were elevated in the high glucose treated cells compared with control. Finally, Anakinra™ was found to attenuate fibronectin expression under high glucose conditions, compared with the untreated cells. Conclusion Proinflammatory IL-1α and IL-1β cytokines are expressed by HK-2 cells upon stimulation with glucose and result in the fibrosis on the cells measured by the production of fibronectin. The addition of Anakinra™, an IL-1 receptor blocker, to the cell culture attenuate the expression of fibronectin by the tubular cells. Our research is the first to describe a causation between hyperglycemia, IL-1 elevated levels and fibrosis in HK-2 cells, as demonstrated by the beneficial effect of Anakinra™ on lowering fibronectin expression.

Eicosapentaenoic acid restores diabetic tubular injury through regulating oxidative stress and mitochondrial apoptosis

2010 ◽  
Vol 299 (6) ◽  
pp. F1451-F1461 ◽  
Author(s):  
Sekiko Taneda ◽  
Kazuho Honda ◽  
Kimiko Tomidokoro ◽  
Kenta Uto ◽  
Kosaku Nitta ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Eicosapentaenoic Acid ◽  
Diabetic Kidney Disease ◽  
Ros Generation ◽  
Mitochondrial Apoptosis ◽  
Diabetic Mice ◽  
Tubular Injury ◽  
Diabetic Kidney ◽  
Tubular Cells

The present study was designed to elucidate a possible mechanism of hyperglycemia-induced tubular injury and to examine a therapeutic potential of dietary eicosapentaenoic acid (EPA) for the prevention of diabetic kidney disease. Utilizing streptozotocin-induced diabetic mice, the extents of albuminuria and histological injuries were monitored at 2 wk after diabetic induction. Reactive oxygen species (ROS) production, apoptosis, and hypoxia in the kidney were evaluated by immunohistochemistry and Western blotting. An in vitro study was performed using rat proximal tubular cells (NRK-52E) to confirm the protective effect of EPA for methylglyoxal (MG)-induced ROS generation and staurosporine (STS)-induced mitochondrial apoptosis. The extents of albuminuria and histological tubular injuries were significantly lower in EPA-treated diabetic mice compared with untreated diabetic mice. The levels of lipid peroxidation product (4-hydroxy-2-nonenal), oxidative DNA damage (8-hydoxy-deoxyguanosine), and mitochondrial apoptosis (TUNEL, caspase-9, cleaved caspase-3, and cytochrome c release) in the tubular cells were also significantly lower in EPA-treated diabetic mice. Furthermore, hypoxia-inducible factor (HIF)-1α expression was significantly upregulated in the kidney tissues from EPA-treated mice compared with untreated diabetic mice. MG-induced ROS overproduction and STS-induced mitochondrial apoptosis in NRK-52E cells were significantly reduced by EPA treatment in vitro. These results indicated that the ROS generation and mitochondrial apoptosis were involved in hyperglycemia-induced tubular injury and EPA had a beneficial effect by suppressing ROS generation and mitochondrial apoptosis partly through augmentation of an HIF-1α response in diabetic kidney disease.

scholarly journals Mitochondrial fission and mitophagy are independent mechanisms regulating ischemia/reperfusion injury in primary neurons

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Anthony R. Anzell ◽  
Garrett M. Fogo ◽  
Zoya Gurm ◽  
Sarita Raghunayakula ◽  
Joseph M. Wider ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Ischemia Reperfusion Injury ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Conditional Knockout ◽  
Mitochondrial Morphology ◽  
Primary Neurons ◽  
Mitochondrial Fragmentation

AbstractMitochondrial dynamics and mitophagy are constitutive and complex systems that ensure a healthy mitochondrial network through the segregation and subsequent degradation of damaged mitochondria. Disruption of these systems can lead to mitochondrial dysfunction and has been established as a central mechanism of ischemia/reperfusion (I/R) injury. Emerging evidence suggests that mitochondrial dynamics and mitophagy are integrated systems; however, the role of this relationship in the context of I/R injury remains unclear. To investigate this concept, we utilized primary cortical neurons isolated from the novel dual-reporter mitochondrial quality control knockin mice (C57BL/6-Gt(ROSA)26Sortm1(CAG-mCherry/GFP)Ganl/J) with conditional knockout (KO) of Drp1 to investigate changes in mitochondrial dynamics and mitophagic flux during in vitro I/R injury. Mitochondrial dynamics was quantitatively measured in an unbiased manner using a machine learning mitochondrial morphology classification system, which consisted of four different classifications: network, unbranched, swollen, and punctate. Evaluation of mitochondrial morphology and mitophagic flux in primary neurons exposed to oxygen-glucose deprivation (OGD) and reoxygenation (OGD/R) revealed extensive mitochondrial fragmentation and swelling, together with a significant upregulation in mitophagic flux. Furthermore, the primary morphology of mitochondria undergoing mitophagy was classified as punctate. Colocalization using immunofluorescence as well as western blot analysis revealed that the PINK1/Parkin pathway of mitophagy was activated following OGD/R. Conditional KO of Drp1 prevented mitochondrial fragmentation and swelling following OGD/R but did not alter mitophagic flux. These data provide novel evidence that Drp1 plays a causal role in the progression of I/R injury, but mitophagy does not require Drp1-mediated mitochondrial fission.

scholarly journals miR-379 deletion ameliorates features of diabetic kidney disease by enhancing adaptive mitophagy via FIS1

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mitsuo Kato ◽  
Maryam Abdollahi ◽  
Ragadeepthi Tunduguru ◽  
Walter Tsark ◽  
Zhuo Chen ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Diabetic Kidney Disease ◽  
Mesangial Cells ◽  
Mitochondrial Fission ◽  
Major Complication ◽  
Body Weight Loss ◽  
Diabetic Kidney ◽  
Guide Rna ◽  
And Oxidative Stress

AbstractDiabetic kidney disease (DKD) is a major complication of diabetes. Expression of members of the microRNA (miRNA) miR-379 cluster is increased in DKD. miR-379, the most upstream 5′-miRNA in the cluster, functions in endoplasmic reticulum (ER) stress by targeting EDEM3. However, the in vivo functions of miR-379 remain unclear. We created miR-379 knockout (KO) mice using CRISPR-Cas9 nickase and dual guide RNA technique and characterized their phenotype in diabetes. We screened for miR-379 targets in renal mesangial cells from WT vs. miR-379KO mice using AGO2-immunopreciptation and CLASH (cross-linking, ligation, sequencing hybrids) and identified the redox protein thioredoxin and mitochondrial fission-1 protein. miR-379KO mice were protected from features of DKD as well as body weight loss associated with mitochondrial dysfunction, ER- and oxidative stress. These results reveal a role for miR-379 in DKD and metabolic processes via reducing adaptive mitophagy. Strategies targeting miR-379 could offer therapeutic options for DKD.

scholarly journals Inflammation and Oxidative Stress in Diabetic Kidney Disease: The Targets for SGLT2 Inhibitors and GLP-1 Receptor Agonists

2021 ◽  
Vol 22 (19) ◽  
pp. 10822
Author(s):  
Agata Winiarska ◽  
Monika Knysak ◽  
Katarzyna Nabrdalik ◽  
Janusz Gumprecht ◽  
Tomasz Stompór
Keyword(s):  
Oxidative Stress ◽  
Kidney Disease ◽  
Diabetic Kidney Disease ◽  
Kidney Injury ◽  
Organ Protection ◽  
In Vivo Models ◽  
Diabetic Kidney ◽  
And Oxidative Stress

The incidence of type 2 diabetes (T2D) has been increasing worldwide, and diabetic kidney disease (DKD) remains one of the leading long-term complications of T2D. Several lines of evidence indicate that glucose-lowering agents prevent the onset and progression of DKD in its early stages but are of limited efficacy in later stages of DKD. However, sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor (GLP-1R) antagonists were shown to exert nephroprotective effects in patients with established DKD, i.e., those who had a reduced glomerular filtration rate. These effects cannot be solely attributed to the improved metabolic control of diabetes. In our review, we attempted to discuss the interactions of both groups of agents with inflammation and oxidative stress—the key pathways contributing to organ damage in the course of diabetes. SGLT2i and GLP-1R antagonists attenuate inflammation and oxidative stress in experimental in vitro and in vivo models of DKD in several ways. In addition, we have described experiments showing the same protective mechanisms as found in DKD in non-diabetic kidney injury models as well as in some tissues and organs other than the kidney. The interaction between both drug groups, inflammation and oxidative stress appears to have a universal mechanism of organ protection in diabetes and other diseases.

scholarly journals miR-125b Disrupts Mitochondrial Dynamics via Targeting Mitofusin 1 in Cisplatin-Induced Acute Kidney Injury

2021 ◽  
pp. 1-11
Author(s):  
Yue Zhao ◽  
Yue Lang ◽  
Mingchao Zhang ◽  
Shaoshan Liang ◽  
Xiaodong Zhu ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Molecular Mechanisms ◽  
Mitochondrial Dynamics ◽  
Kidney Injury ◽  
Immunofluorescent Staining ◽  
Luciferase Reporter ◽  
Mitochondrial Fragmentation ◽  
Tubular Cells ◽  
Renal Tubular Cells

<b><i>Background:</i></b> Mitochondria are dynamic organelles whose structure are maintained by continuous fusion and fission. During acute kidney injury (AKI) progression, mitochondrial fission in renal tubular cells was elevated, characterized by mitochondrial fragmentation. It is tightly associated with mitochondrial dysfunction, which has been proven as a critical mechanism responsible for AKI. However, the initiating factor for the disruption of mitochondrial dynamics in AKI was not well understood. <b><i>Objectives:</i></b> To explore the molecular mechanisms of mitochondrial disorders and kidney damage. <b><i>Methods:</i></b> We established cisplatin-induced AKI model in C57BL/6 mice and proximal tubular cells, and detected the expression of miR-125b by qPCR. Then we delivered miR-125b antagomir after cisplatin treatment in mice via hydrodynamic-based gene transfer technique. Subsequently, we performed luciferase reporter and immunoblotting ­assays to prove miR-125b could directly modulate mitofusin1 (MFN1) expression. We also tested the role of miR-125b in mitochondrial and renal injury through immunofluorescent staining, qPCR, and immunoblotting assays. <b><i>Results:</i></b> miR-125b levels were induced in cisplatin-challenged mice and cultured tubular cells. Anti-miR-125b could effectively alleviate cisplatin-induced mitochondrial fragmentation and kidney injury both in vitro and in vivo. Furthermore, miR-125b could directly regulate MFN1, which is a key regulator of mitochondrial fusion. Our study indicated that miR-125b is upregulated during cisplatin-induced AKI. Inhibition of miR-125b may suppress mitochondrial and renal damage through upregulating MFN1. This study suggests that miR-125b could be a potential therapeutic target in AKI.

scholarly journals The Loss of Mitochondrial Quality Control in Diabetic Kidney Disease

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenni Dai ◽  
Hengcheng Lu ◽  
Yinyin Chen ◽  
Danyi Yang ◽  
Lin Sun ◽  
...  
Keyword(s):  
Quality Control ◽  
Kidney Disease ◽  
Diabetic Kidney Disease ◽  
Protein Quality ◽  
Current Knowledge ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Protein ◽  
Eukaryotic Cell ◽  
Mitochondrial Quality Control ◽  
Diabetic Kidney

Diabetic kidney disease (DKD) is the predominant complication of diabetes mellitus (DM) and the leading cause of chronic kidney disease and end-stage renal disease worldwide, which are major risk factors for death. The pathogenesis of DKD is very complicated, including inflammation, autophagy impairment, oxidative stress, and so on. Recently, accumulating evidence suggests that the loss of mitochondrial quality control exerts critical roles in the progression of DKD. Mitochondria are essential for eukaryotic cell viability but are extremely vulnerable to damage. The mechanisms of mitochondrial quality control act at the molecular level and the organelle level, including mitochondrial dynamics (fusion and fission), mitophagy, mitochondrial biogenesis, and mitochondrial protein quality control. In this review, we summarize current knowledge of the role of disturbances in mitochondrial quality control in the pathogenesis of DKD and provide potential insights to explore how to delay the onset and development of DKD.

scholarly journals Diabetic Kidney Disease Alters the Transcriptome and Function of Human Adipose-Derived Mesenchymal Stromal Cells but Maintains Immunomodulatory and Paracrine Activities Important for Renal Repair

2021 ◽  
Author(s):  
LaTonya J. Hickson ◽  
Alfonso Eirin ◽  
Sabena M. Conley ◽  
Timucin Taner ◽  
Xiaohui Bian ◽  
...  
Keyword(s):  
Growth Factor ◽  
Kidney Disease ◽  
Stromal Cells ◽  
Diabetic Kidney Disease ◽  
Transforming Growth Factor ◽  
Inflammatory Marker ◽  
Patient Characteristics ◽  
Rna Seq ◽  
Diabetic Kidney

<a>Mesenchymal stem/stromal cells (MSC) facilitate repair in experimental diabetic kidney disease (DKD). However, the hyperglycemic and uremic milieu may diminish regenerative capacity of patient-derived therapy. We hypothesized that DKD reduces human MSC paracrine function. Adipose-derived MSC from 38 DKD participants and 16 controls were assessed for cell surface markers, tri-lineage differentiation, RNA-sequencing (RNA-seq), <i>in vitro</i> function (co-culture or conditioned medium experiments with T cells and human kidney cells [HK-2]), secretome profile, and cellular senescence abundance. The direction of association between MSC function and patient characteristics were also tested. RNA-seq analysis identified 353 differentially expressed genes and downregulation of several immunomodulatory genes/pathways in DKD- <i>vs</i>. Control-MSC. DKD-MSC phenotype, differentiation, and tube formation capacity were preserved but migration was reduced. DKD-MSC with and without interferon-γ priming inhibited T-cell proliferation greater than Control-MSC. DKD-MSC-medium contained higher levels of anti-inflammatory cytokines (indoleamine 2,3-deoxygenase-1 and prostaglandin-E2) and pro-repair factors (hepatocyte growth factor and stromal cell-derived factor-1) but lower Interleukin-6 vs. Control-MSC-medium. DKD-MSC-medium protected high glucose plus transforming growth factor-β-exposed HK-2 cells by reducing apoptotic, fibrotic and inflammatory marker expression. Few DKD-MSC functions were affected by patient characteristics including age, gender, body mass index, hemoglobin A1c, kidney function or urine albumin excretion. However, senescence-associated-β-galactosidase activity was lower in DKD-MSC from participants on metformin therapy. Therefore, while </a><a>DKD altered the transcriptome and migratory function of culture-expanded MSC, DKD-MSC functionality, trophic factor secretion and immunomodulatory activities contributing to repair remained intact. </a>These observations support testing patient-derived MSC therapy and may inform preconditioning regimens in DKD clinical trials.

scholarly journals S-Nitrosylation of RhoGAP Myosin9A Is Altered in Advanced Diabetic Kidney Disease

2021 ◽  
Vol 8 ◽  
Author(s):  
Qi Li ◽  
Delma Veron ◽  
Alda Tufro
Keyword(s):  
Kidney Disease ◽  
High Glucose ◽  
Diabetic Kidney Disease ◽  
Diabetic Mice ◽  
Post Translational Modification ◽  
No Donor ◽  
Diabetic Kidney ◽  
Rhoa Activity

The molecular pathogenesis of diabetic kidney disease progression is complex and remains unresolved. Rho-GAP MYO9A was recently identified as a novel podocyte protein and a candidate gene for monogenic FSGS. Myo9A involvement in diabetic kidney disease has been suggested. Here, we examined the effect of diabetic milieu on Myo9A expression in vivo and in vitro. We determined that Myo9A undergoes S-nitrosylation, a post-translational modification dependent on nitric oxide (NO) availability. Diabetic mice with nodular glomerulosclerosis and severe proteinuria associated with doxycycline-induced, podocyte-specific VEGF164 gain-of-function showed markedly decreased glomerular Myo9A expression and S-nitrosylation, as compared to uninduced diabetic mice. Immortalized mouse podocytes exposed to high glucose revealed decreased Myo9A expression, assessed by qPCR, immunoblot and immunocytochemistry, and reduced Myo9A S-nitrosylation (SNO-Myo9A), assessed by proximity link assay and biotin switch test, functionally resulting in abnormal podocyte migration. These defects were abrogated by exposure to a NO donor and were not due to hyperosmolarity. Our data demonstrate that high-glucose induced decrease of both Myo9A expression and SNO-Myo9A is regulated by NO availability. We detected S-nitrosylation of Myo9A interacting proteins RhoA and actin, which was also altered by high glucose and NO dependent. RhoA activity inversely related to SNO-RhoA. Collectively, data suggest that dysregulation of SNO-Myo9A, SNO-RhoA and SNO-actin may contribute to the pathogenesis of advanced diabetic kidney disease and may be amenable to therapeutic targeting.

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