scholarly journals PFKP Activation Ameliorates Foot Process Fusion in Podocytes in Diabetic Kidney Disease

2022 ◽  
Vol 12 ◽  
Author(s):  
Zongwei Zhang ◽  
Wei Liang ◽  
Qiang Luo ◽  
Hongtu Hu ◽  
Keju Yang ◽  
...  

BackgroundGlycolysis dysfunction is an important pathogenesis of podocyte injury in diabetic kidney disease (DKD). Foot process fusion of podocytes and increased albuminuria are markers of early DKD. Moreover, cytoskeletal remodeling has been found to be involved in the foot process fusion of podocytes. However, the connections between cytoskeletal remodeling and alterations of glycolysis in podocytes in DKD have not been clarified.MethodsmRNA sequencing of glomeruli obtained from db/db and db/m mice with albuminuria was performed to analyze the expression profiling of genes in glucose metabolism. Expressions of phosphofructokinase platelet type (PFKP) in the glomeruli of DKD patients were detected. Clotrimazole (CTZ) was used to explore the renal effects of PFKP inhibition in diabetic mice. Using Pfkp siRNA or recombinant plasmid to manipulate PFKP expression, the effects of PFKP on high glucose (HG) induced podocyte damage were assessed in vitro. The levels of fructose-1,6-bisphosphate (FBP) were measured. Targeted metabolomics was performed to observe the alterations of the metabolites in glucose metabolism after HG stimulation. Furthermore, aldolase type b (Aldob) siRNA or recombinant plasmid were applied to evaluate the influence of FBP level alteration on podocytes. FBP was directly added to podocyte culture media. Db/db mice were treated with FBP to investigate its effects on their kidney.ResultsmRNA sequencing showed that glycolysis enzyme genes were altered, characterized by upregulation of upstream genes (Hk1, and Pfkp) and down-regulation of downstream genes of glycolysis (Pkm, and Ldha). Moreover, the expression of PFKP was increased in glomeruli of DKD patients. The CTZ group presented more severe renal damage. In vitro, the Pfkp siRNA group and ALDOB overexpression group showed much more induced cytoskeletal remodeling in podocytes, while overexpression of PFKP and suppression of ALDOB in vitro rescued podocytes from cytoskeletal remodeling through regulation of FBP levels and inhibition of the RhoA/ROCK1 pathway. Furthermore, targeted metabolomics showed FBP level was significantly increased in HG group compared with the control group. Exogenous FBP addition reduced podocyte cytoskeletal remodeling and renal damage of db/db mice.ConclusionsThese findings provide evidence that PFKP may be a potential target for podocyte injury in DN and provide a rationale for applying podocyte glycolysis enhancing agents in patients with DKD.

2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Qiongxia Deng ◽  
Ruowei Wen ◽  
Sirui Liu ◽  
Xiaoqiu Chen ◽  
Shicong Song ◽  
...  

Abstract Excessive mitochondrial fission plays a key role in podocyte injury in diabetic kidney disease (DKD), and long noncoding RNAs (lncRNAs) are important in the development and progression of DKD. However, lncRNA regulation of mitochondrial fission in podocytes is poorly understood. Here, we studied lncRNA maternally expressed gene 3 (Meg3) in mitochondrial fission in vivo and in vitro using human podocytes and Meg3 podocyte-specific knockdown mice. Expression of lncRNA Meg3 in STZ-induced diabetic mice was higher, and correlated with the number of podocytes. Excessive mitochondrial fission of podocytes and renal histopathological and physiological parameters were improved in podocyte-specific Meg3 knockdown diabetic mice. Elongated mitochondria with attenuated podocyte damage, as well as mitochondrial translocation of dynamin-related protein 1 (Drp1), were decreased in Meg3 knockout podocytes. By contrast, increased fragmented mitochondria, podocyte injury, and Drp1 expression and phosphorylation were observed in lncRNA Meg3-overexpressing podocytes. Treatment with Mdivi1 significantly blunted more fragmented mitochondria and reduced podocyte injury in lncRNA Meg3-overexpressing podocytes. Finally, fragmented mitochondria and Drp1 mitochondrial translocation induced by high glucose were reduced following treatment with Mdivi1. Our data show that expression of Meg3 in podocytes in both human cells and diabetic mice was higher, which regulates mitochondrial fission and contributes to podocyte injury through increased Drp1 and its translocation to mitochondria.


2021 ◽  
Vol 22 (19) ◽  
pp. 10822
Author(s):  
Agata Winiarska ◽  
Monika Knysak ◽  
Katarzyna Nabrdalik ◽  
Janusz Gumprecht ◽  
Tomasz Stompór

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.


2019 ◽  
Vol 59 ◽  
pp. 13-23 ◽  
Author(s):  
Yipeng Liu ◽  
Hong Su ◽  
Chaoqun Ma ◽  
Dong Ji ◽  
Xiaoli Zheng ◽  
...  

2020 ◽  
Vol 34 (11) ◽  
pp. 15577-15590
Author(s):  
Daisuke Fujimoto ◽  
Takashige Kuwabara ◽  
Yusuke Hata ◽  
Shuro Umemoto ◽  
Tomoko Kanki ◽  
...  

2021 ◽  
Author(s):  
LaTonya J. Hickson ◽  
Alfonso Eirin ◽  
Sabena M. Conley ◽  
Timucin Taner ◽  
Xiaohui Bian ◽  
...  

<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.


2021 ◽  
Vol 8 ◽  
Author(s):  
Qi Li ◽  
Delma Veron ◽  
Alda Tufro

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.


2021 ◽  
Author(s):  
LaTonya J. Hickson ◽  
Alfonso Eirin ◽  
Sabena M. Conley ◽  
Timucin Taner ◽  
Xiaohui Bian ◽  
...  

<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.


2020 ◽  
Vol 51 (9) ◽  
pp. 676-692
Author(s):  
Marita Liebisch ◽  
Gunter Wolf

Background: Chronic hyperglycemia, a pivotal feature of diabetes mellitus (DM), initiates the formation of advanced glycation end products (AGEs) and the dysregulation of epigenetic mechanisms, which may cause injury to renal podocytes, a central feature of diabetic kidney disease (DKD). Previous data of our group showed that AGEs significantly reduce the expression of NIPP1 (nuclear inhibitor of protein phosphatase 1) in podocytes in vitro as well as in human and murine DKD. NIPP1 was shown by others to interact with enhancer of zeste homolog 2 (EZH2), which catalyzes the repressive methylation of H3K27me3 on histone 3. Therefore, we hypothesized that AGEs can directly induce epigenetic changes in podocytes. Methods: We analyzed the relevance of AGEs on EZH2 expression and activity in a murine podocyte cell line. Cells were treated with 5 mg/mL glycated BSA for 24 h. To determine the meaning of EZH2 suppression, EZH2 activity was inhibited by incubating the cells with the pharmacological methyltransferase inhibitor 3-deazaneplanocin A; EZH2 expression was repressed with siRNA. mRNA expression was analyzed with real-time PCR, and protein expression with Western blot. EZH2 expression and level of H3K27 trimethylation in podocytes of diabetic db/db mice, a mouse model for type 2 DM, were analyzed using immunofluorescence. Results: Our data demonstrated that AGEs decrease EZH2 expression in podocytes and consequently reduce H3K27me3. This suppression of EZH2 mimicked the AGE effects and caused an upregulated expression of pathological factors that contribute to podocyte injury in DKD. In addition, analyses of db/db mice showed significantly reduced H3K27me3 and EZH2 expression in podocytes. Moreover, the suppression of NIPP1 and EZH2 showed similar effects regarding podocyte injury. Conclusions: Our studies provide a novel pathway how AGEs contribute to podocyte injury and the formation of the so-called metabolic memory in DKD.


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