Ectopic lipid accumulation: potential role in tubular injury and inflammation in diabetic kidney disease

2018 ◽  
Vol 132 (22) ◽  
pp. 2407-2422 ◽  
Author(s):  
Wenxia Yang ◽  
Ying Luo ◽  
Shikun Yang ◽  
Mengru Zeng ◽  
Shumin Zhang ◽  
...  

Emerging studies suggest that lipid accumulates in the kidneys during diabetic kidney disease (DKD). However, the correlation between ectopic lipid accumulation with tubular damage has not been thoroughly elucidated to date. Using Oil Red staining, lipid accumulation was observed in the kidneys of type 2 DKD patients (classes II–III) and db/db mice compared with the control and was predominantly located in the proximal tubular compartment. Immunohistochemistry (IHC) staining showed that the intensity of adipose differentiation related protein (ADRP) and sterol regulatory element binding protein-1 (SREBP-1) was clearly up-regulated, which was positively correlated with the tubulointerstitial damage score and inflammation. Furthermore, the urine ADRP content significantly increased in DKD patients compared with the control, which positively correlated with abnormal lipid metabolism, serum creatinine, urine N-acetyl-β-glucosaminidase (NAG), albumin excretion (albumin-to-creatinine ratio (ACR)), and tumor necrosis factor-α (TNF-α) expression. However, there was no significant difference observed in plasma ADRP levels. In addition, the expression of SREBP-1 protein was dramatically increased in peripheral blood mononuclear cells (PBMCs) isolated from DKD patients, which was also tightly correlated with urine NAG, ACR, and TNF-α levels. In vitro studies demonstrated increased ADRP and SREBP-1 expression accompanied by lipid accumulation in HK-2 cells cultured in high glucose (HG). HG induced high levels of TNF-α expression, which was partially blocked by transfection of ADRP siRNA or SREBP-1 siRNA. These data indicated that ADRP and SREBP-1 are crucial factors that mediate lipid accumulation with tubular damage and inflammation in DKD, and ectopic lipid accumulation may serve as a novel therapeutic target for amelioration of tubular injury in DKD.

Life ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 224
Author(s):  
Jaehyun Bae ◽  
Young Jun Won ◽  
Byung-Wan Lee

Diabetic kidney disease (DKD) is one of the most common forms of chronic kidney disease. Its pathogenic mechanism is complex, and it can affect entire structures of the kidney. However, conventional approaches to early stage DKD have focused on changes to the glomerulus. Current standard screening tools for DKD, albuminuria, and estimated glomerular filtration rate are insufficient to reflect early tubular injury. Therefore, many tubular biomarkers have been suggested. Non-albumin proteinuria (NAP) contains a wide range of tubular biomarkers and is convenient to measure. We reviewed the clinical meanings of NAP and its significance as a marker for early stage DKD.


2021 ◽  
Vol 18 (1) ◽  
pp. 147916412199252
Author(s):  
Yuwei Yang ◽  
Peng Xu ◽  
Yan Liu ◽  
Xiaohong Chen ◽  
Yiyang He ◽  
...  

Aim: Atherosclerosis involves vascular endothelial damage and lipid metabolism disorder, which is closely related to the occurrence and development of diabetic kidney disease (DKD). However, studies on non-high albuminuria DKD (NHADKD) with an albumin to creatinine ratio (ACR) <30 mg/g are rare. This study is to investigate the relationship between atherogenic factors and the occurrence of NHADKD. Methods: Serum lipid indicators, lipoprotein-associated phospholipase A2 (Lip-PLA2) and homocysteine levels were measured in 1116 subjects to analyze their relationship with NHADKD. Results: Among all subjects, Lip-PLA2 had the closest but relatively weak correlation with ACR ( r = 0.297, p < 0.001) and only homocysteine was moderately correlated with eGFR ( r = −0.465, p < 0.001). However, in patients with NHADKD, these atherosclerotic factors were weakly correlated or uncorrelated with eGFR (max. | r| = 0.247). Stratified risk analysis showed that when ACR was <10 mg/g, homocysteine [OR = 6.97(4.07–11.95)], total cholesterol (total-Chol) [OR = 6.04(3.03–12.04)], and high-density lipoprotein cholesterol (HDL-Chol) [OR = 5.09(2.99–8.64)] were risk factors for NHADKD. There was no significant difference of OR between these three factors ( Z = 0.430–1.044, all p > 0.05). When ACR was ⩾10mg/g, homocysteine [OR = 17.26(9.67–30.82)] and total-Chol [OR = 5.63(2.95–10.76)] were risk factors for NHADKD, and ORhomocysteine was significantly higher than ORtotal-Chol ( Z = 3.023, p < 0.05). Conclusions: The occurrence of NHADKD may be related to the levels of homocysteine, total-Chol, HDL-Chol, and Lip-PLA2 in blood. Among them, homocysteine may be most closely related to NHADKD.


2020 ◽  
Vol 4 (4) ◽  
Author(s):  
Igor Kravets ◽  
Sandeep K Mallipattu

Abstract Diabetic kidney disease (DKD) is an important public health problem. Podocyte injury is a central event in the mechanism of DKD development. Podocytes are terminally differentiated, highly specialized glomerular visceral epithelial cells critical for the maintenance of the glomerular filtration barrier. Although potential mechanisms by which diabetic milieu contributes to irreversible loss of podocytes have been described, identification of markers that prognosticate either the development of DKD or the progression to end-stage kidney disease (ESKD) have only recently made it to the forefront. Currently, the most common marker of early DKD is microalbuminuria; however, this marker has significant limitations: not all diabetic patients with microalbuminuria will progress to ESKD and as many as 30% of patients with DKD have normal urine albumin levels. Several novel biomarkers indicating glomerular or tubular damage precede microalbuminuria, suggesting that the latter develops when significant kidney injury has already occurred. Because podocyte injury plays a key role in DKD pathogenesis, identification of markers of early podocyte injury or loss may play an important role in the early diagnosis of DKD. Such biomarkers in the urine include podocyte-released microparticles as well as expression of podocyte-specific markers. Here, we review the mechanisms by which podocyte injury contributes to DKD as well as key markers that have been recently implicated in the development and/or progression of DKD and might serve to identify individuals that require earlier preventative care and treatment in order to slow the progression to ESKD.


2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Yue Wang ◽  
Zong-ji Zheng ◽  
Yi-jie Jia ◽  
Yan-lin Yang ◽  
Yao-ming Xue

2018 ◽  
Vol 5 (6) ◽  
pp. 171871 ◽  
Author(s):  
Xin-Ge Yue ◽  
Zai-Gang Yang ◽  
Yue Zhang ◽  
Gui-Jun Qin ◽  
Fei Liu

To investigate the correlations between SIRT1 gene polymorphisms and diabetic kidney disease (DKD). There were 150 patients with DKD in the observation group (urinary albumin excretion rate (UAER) ≥ 300 mg 24 h −1 ), and 160 patients with a more than 10 year history of type 2 diabetes but without retinopathy and DKD (UAER < 30 mg 24 h −1 ) in the control group. Genotypes of three tagged single-nucleotide polymorphism loci (rs3818292, rs4746720 and rs10823108) in the SIRT1 gene in the two groups were detected. Risks of DKD for patients with the GG and GG + AG genotype in the rs10823108 locus of the SIRT1 gene were 2.96 and 2.92 times higher than that for AA genotype carriers, respectively. The risk of DKD for patients with the GG genotype in the rs3818292 locus was 0.23 times and 0.21 times higher than that for AA and for AA + AG genotype carriers, respectively, and the risk of DKD for patients with allele G was 0.66 times higher than that for allele A carriers. There was no significant difference in genotype frequency of rs4746720 locus gene polymorphisms between the observation and control groups. The SIRT1 gene is a genetic susceptibility gene of DKD. Mutation genotype GG and GG + AG in the rs10823108 locus can increase the risk of DKD. Mutation genotype GG and allele G in the rs3818292 locus can decrease the risk of DKD.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Thoria A. Omar ◽  
Shimaa K. Zewain ◽  
Mohamed M. Ghonaim ◽  
Khadija A. Refaat ◽  
Dalia H. Abou-Elela

Abstract Background Diabetic kidney disease (DKD) is a progressive kidney disease that affects diabetic patients irrespective of glycemic state or hypertension. Therefore, early detection of DKD is of critical importance. Many genome-wide association studies have identified the engulfment and cell motility 1 (ELMO1) gene as a genetic marker linked to DKD. This study aimed to investigate the association between ELMO1 rs741301 gene polymorphism and the development of DKD among Egyptian patients with type 2 diabetes mellitus (T2DM). Allele and genotype frequencies were investigated in 304 subjects by real-time PCR allelic discrimination assay: 100 DKD patients, 102 diabetic patients without DKD, and 102 healthy controls. Results GG genotype of ELMO1 (rs741301) SNP and its allele frequencies were significantly high in all diabetic patients. GG genotype had an odds ratio (OR) of 6.095 and 95% confidence interval (CI) of 2.456–15.125, p < 0.001, while the frequent allele G had an OR of 2.366 and 95% CI of 1.450–3.859, p = 0.001. No significant difference was observed between T2DM without DKD and DKD. Conclusion Our results could not establish an association between the ELMO1 rs741301 variant and the progression of DKD.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Agnieszka Gala-Błądzińska ◽  
Paulina Dumnicka ◽  
Beata Kuśnierz-Cabala ◽  
Katarzyna Rybak ◽  
Ryszard Drożdż ◽  
...  

Background. Two clinical phenotypes of diabetic kidney disease (DKD) have been reported, that is, with or without increased albuminuria. The aim of study was to assess the usefulness of urinary neutrophil gelatinase-associated lipocalin (uNGAL) for the early diagnosis of DKD in the type 2 diabetes mellitus (T2DM). Methods. The study group consisted of 123 patients with T2DM (mean age 62 ± 14 years), with urine albumin/creatinine ratio (uACR) < 300 mg/g and eGFR ≥ 60 ml/min/1.73 m2. The control group included 22 nondiabetic patients with comparable age, sex, and comorbidities. uNGAL, albumin, and creatinine were measured in the first morning urine samples. uACR and uNGAL/creatinine ratios (uNCR) were calculated. Results. In the control group, maximum uNCR was 39.64 µg/g. In T2DM group, 24 patients (20%) had higher results, with the maximum value of 378.6 µg/g. Among patients with uNCR > 39.64 µg/g, 13 (54%) did not have markedly increased albuminuria. Women with T2DM had higher uNCR than men (p<0.001), without difference in uACR (p=0.09). uNCR in T2DM patients correlated significantly with HbA1c. Sex, total cholesterol, and uACR were independent predictors of uNCR above 39.64 µg/g. Conclusions. Increased uNGAL and uNCR may indicate early tubular damage, associated with dyslipidemia and worse diabetes control, especially in females with T2DM.


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