Damage In Diabetic Nephropathy Research Articles

Indoxyl Sulfate Aggravates Podocyte Damage through the TGF-β1/Smad/ROS Signalling Pathway.

Hyperglycaemia induces the production of a large quantity of reactive oxygen species (ROS) and activates the transforming growth factor β1 (TGF-β1)/Smad signalling pathway, which is the main initiating factor in the formation of diabetic nephropathy. Indoxyl sulphate (IS) is a protein-binding gut-derived uraemic toxin that localizes to podocytes, induces oxidative stress, and inflames podocytes. The involvement of podocyte damage in diabetic nephropathy through the TGF-β1 signalling pathway is still unclear. In this study, we cultured differentiated rat podocytes in vitro and measured the expression levels of nephrin, synaptopodin, CD2AP, SRGAP2a, and α-SMA by quantitative real-time PCR (qRT-PCR) and Western blotting after siRNA-mediated TGF-β1 silencing, TGF-β1 overexpression, and the presence of the ROS inhibitor acetylcysteine. We detected the expression levels of nephrin, synaptopodin, CD2AP, SRGAP2a, small mother against decapentaplegic (Smad)2/3, phosphorylated-Smad2/3 (p-Smad2/3), Smad7, NADPH oxidase 4 (NOX4), and ROS levels under high glucose (HG) and IS conditions. The results indicated that nephrin, synaptopodin, CD2AP, and SRGAP2a expressions were significantly upregulated, and α-SMA expression was significantly downregulated in the presence of HG under siRNA-mediated TGF-β1 silencing or after the addition of acetylcysteine. However, in the presence of HG, the expressions of nephrin, synaptopodin, CD2AP, and SRGAP2a were significantly downregulated, and the expression of α-SMA was significantly upregulated with the overexpression of TGF-β1. IS supplementation under HG conditions further significantly reduced the expressions of nephrin, synaptopodin, CD2AP, and SRGAP2a; altered the expressions of Smad2/3, p-Smad2/3, Smad7, and NOX4; and increased ROS production in podocytes. This study suggests that IS may modulate the expression of nephrin, synaptopodin, CD2AP, and SRGAP2a by regulating the ROS and TGF-β1/Smad signalling pathways, providing new theoretical support for the treatment of diabetic nephropathy.

Protective effect of salidroside on renal damage in diabetic nephropathy mice by regulating RAGE/JAK1/STAT signaling pathway

This study aims to investigate the protective effect of salidroside(SAL) on renal damage in diabetic nephropathy(DN) mice based on the receptor for advanced glycation end products/janus activated kinase 1/signal transduction and activator of transcription 3(RAGE/JAK1/STAT3) signaling pathway. The mouse DN model was established by high-fat/high-sucrose diets combined with intraperitoneal injection of streptozocin(STZ). Mice were randomly divided into normal group, model group, low-dose SAL group(20 mg·kg~(-1)), high-dose SAL group(100 mg·kg~(-1)), and metformin group(140 mg·kg~(-1)), with 12 mice in each group. After establishing the DN model, mice were given drugs or solvent intragastrically, once a day for consecutive 10 weeks. Body weight, daily water intake, and fasting blood glucose(FBG) were measured every two weeks. After the last dose, the glucose tolerance test was performed, and the samples of 24-hour urine, serum, and kidney tissue were collected. The levels of 24 hours urinary total protein(24 h-UTP), serum creatinine(Scr), blood urea nitrogen(BUN), triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol(LDL-C), and high density lipoprotein cholesterol(HDL-C) were detected by biochemical tests. Periodic acid-schiff(PAS) staining was used to observe the pathological changes in the kidney tissue. The protein expressions of α-smooth muscle actin(α-SMA), vimentin, and advanced glycation end products(AGEs) in kidneys were detected by immunohistochemical staining. The activities of superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase(GSH-PX), and the level of malondialdehyde(MDA) in kidneys were detected by using a corresponding detection kit. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of AGEs, carboxymethyllysine(CML), and carboxyethyllysine(CEL) in serum. The protein expressions of RAGE and the phosphorylation level of JAK1 and STAT3 in kidneys were detected by Western blot. Compared with the normal group, the levels of FBG, the area under the curve of glucose(AUCG), water intake, kidney index, 24 h-UTP, tubular injury score, extracellular matrix deposition ratio of the renal glomerulus, the serum levels of Scr, BUN, TG, LDL-C, AGEs, CEL, and CML, the level of MDA, the protein expressions of α-SMA, vimentin, AGEs, and RAGE, and the phosphorylation level of JAK1 and STAT3 in kidney tissue were increased significantly(P<0.01), while the level of HDL-C in serum and the activity of SOD, CAT, and GSH-PX in kidney tissue were decreased significantly(P<0.01). Compared with the model group, the above indexes of the high-dose SAL group were reversed significantly(P<0.05 or P<0.01). In conclusion, this study suggests that SAL can alleviate oxidative stress and renal fibrosis by inhibiting the activation of AGEs-mediated RAGE/JAK1/STAT3 signaling axis, thus playing a potential role in the treatment of DN.

Lycopene prevents cell death in NRK-52E cells by inhibition of high glucose-activated DNA damage and apoptotic, autophagic, and necrotic pathways.

This study aims to investigate the effects of lycopene on apoptotic, autophagic, and necrotic pathways, oxidative status, and DNA damage in diabetic nephropathy at the molecular level. The sample of the study includes seven groups: lycopene (L), high glucose (G), high glucose + lycopene (GL), and control (C) groups tested at 12 and 24 h. The expression levels of genes in oxidative, apoptotic, autophagic, and necrotic cell death pathways are determined by reverse transcription-quantitative polymerase chain reaction analysis. The comet assay method is used for the analysis of DNA damage. It is observed that adding lycopene to high glucose for protective purposes reduces the expression of genes related to apoptosis, autophagy, and necrosis, as well as the DNA damage index, compared to cells given high glucose alone. Lycopene can be a safe and effective alternative agent.

ITGAM-mediated macrophages contribute to basement membrane damage in diabetic nephropathy and atherosclerosis

BackgroundDiabetic nephropathy (DN) and atherosclerosis (AS) are prevalent and severe complications associated with diabetes, exhibiting lesions in the basement membrane, an essential component found within the glomerulus, tubules, and arteries. These lesions contribute significantly to the progression of both diseases, however, the precise underlying mechanisms, as well as any potential shared pathogenic processes between them, remain elusive.MethodsOur study analyzed transcriptomic profiles from DN and AS patients, sourced from the Gene Expression Omnibus database. A combination of integrated bioinformatics approaches and machine learning models were deployed to identify crucial genes connected to basement membrane lesions in both conditions. The role of integrin subunit alpha M (ITGAM) was further explored using immune infiltration analysis and genetic correlation studies. Single-cell sequencing analysis was employed to delineate the expression of ITGAM across different cell types within DN and AS tissues.ResultsOur analyses identified ITGAM as a key gene involved in basement membrane alterations and revealed its primary expression within macrophages in both DN and AS. ITGAM was significantly correlated with tissue immune infiltration within these diseases. Furthermore, the expression of genes encoding core components of the basement membrane was influenced by the expression level of ITGAM.ConclusionOur findings suggest that macrophages may contribute to basement membrane lesions in DN and AS through the action of ITGAM. Moreover, therapeutic strategies that target ITGAM may offer potential avenues to mitigate basement membrane lesions in these two diabetes-related complications.

Correlation between peripheral blood α1-MG, DNMT1 expression, and the severity of diabetic nephropathy renal pathological damage.

To explore the correlation between peripheral blood α1-microglobulin (α1-MG) and monocyte DNA methyltransferase 1 (DNMT1) expression and the severity of renal pathological damage in diabetic nephropathy (DN). The study group comprised 100 patients with DN who underwent treatment at our hospital from January 2022 to January 2023, while the control group consisted of 50 patients with uncomplicated diabetes. The relative expression levels of peripheral blood α1-MG and DNMT1 were compared between the 2 groups of patients. Additionally, the levels of vascular endothelial growth factor (VEGF) were measured, and the diagnostic value of DN was explored using ROC curves. Furthermore, the correlation between the aforementioned indicators and the severity of renal pathological damage in the patients of the study group was analyzed. Compared to the patients in the control group, the patients in the study group showed increased relative expression levels of peripheral blood α1-MG and DNMT1, as well as elevated levels of VEGF (P < .05). The diagnostic value of peripheral blood α1-MG, DNMT1 relative expression levels, and VEGF levels for DN was explored using ROC curves. The AUC values were 0.907, 0.923, and 0.936, respectively (P < .05). The relative expression levels of peripheral blood α1-MG, DNMT1, and VEGF levels in DN patients increase with the elevation of the interstitial fibrosis and tubular atrophy scoring (IFTA) score, showing a positive correlation with r-values of 0.651, 0.710, and 0.628, respectively (P < .05). The relative expression levels of peripheral blood α1-MG, DNMT1, and VEGF levels in DN patients increase with the elevation of the interstitial inflammation score, showing a positive correlation with r-values of 0.771, 0.633, and 0.678, respectively (P < .05). The relative expression levels of peripheral blood α1-MG, DNMT1, and VEGF levels in DN patients increase with the elevation of the glomerular grading, showing a positive correlation with r-values of 0.714, 0.609, and 0.677, respectively (P < .05). The expression levels of peripheral blood α1-MG, DNMT1, and VEGF are significantly elevated in patients with DN. These levels show a positive correlation with the IFTA score, interstitial inflammation score, and glomerular grading, contributing to the diagnosis and assessment of DN.

DsbA-L interacting with catalase in peroxisome improves tubular oxidative damage in diabetic nephropathy

Peroxisomes are metabolically active organelles that are known for exerting oxidative metabolism, but the precise mechanism remains unclear in diabetic nephropathy (DN). Here, we used proteomics to uncover a correlation between the antioxidant protein disulfide-bond A oxidoreductase-like protein (DsbA-L) and peroxisomal function. In vivo, renal tubular injury, oxidative stress, and cell apoptosis in high-fat diet plus streptozotocin (STZ)-induced diabetic mice were significantly increased, and these changes were accompanied by a "ghost" peroxisomal phenotype, which was further aggravated in DsbA-L-deficient diabetic mice. In vitro, the overexpression of DsbA-L in peroxisomes could improve peroxisomal phenotype and function, reduce oxidative stress and cell apoptosis induced by high glucose (HG, 30 mM) and palmitic acid (PA, 250 μM), but this effect was reversed by 3-Amino-1,2,4-triazole (3-AT, a catalase inhibitor). Mechanistically, DsbA-L regulated the activity of catalase by binding to it, thereby reducing peroxisomal leakage and proteasomal degradation of peroxisomal matrix proteins induced by HG and PA. Additionally, the expression of DsbA-L in renal tubules of patients with DN significantly decreased and was positively correlated with peroxisomal function. Taken together, these results highlight an important role of DsbA-L in ameliorating tubular injury in DN by improving peroxisomal function.

#4176 ROLE OF KIDNEY FUNCTION ON NRF2 MRNA LEVELS IN TYPE-2 DIABETES

Abstract Background and Aims Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that induces the expression of genes coding for antioxidant proteins and phase II detoxifying enzymes. Repressor molecule Kelch-like ECH-associated protein 1 (Keap1) and several microRNAs (miRNA) negatively regulate Nrf2 gene expression at post-transcriptional level. Oxidative stress is a major factor for kidney damage in diabetes but the role of Nrf2 in kidney dysfunction in diabetes is still unclear. Method To test whether the gene expression of Nrf-2 is downregulated in type-2 diabetes and whether kidney dysfunction per se further reduces Nrf2 in diabetic patients with diabetic nephropathy, we carried out a case-control study including 99 participants divided into three independent groups: 33 patients with diabetic nephropathy (DN), 33 patients with type 2 diabetes without nephropathy (D) and 33 control subjects (C), all accurately matched for age and sex. Standard ANOVA compared outcome measures in the three groups. Multiple linear regression analysis was used to test the expression levels of Keap1, miR-28-5p, miR-93-5p, miR-30e-5p, miR-125b-5p and miR-150-5p as potential mediators in the observed reduction of Nrf2 mRNA levels in patients with diabetic nephropathy. Results In patients with diabetic nephropathy, Nrf2 gene expression levels (0.82 arbitrary units, AU, IQR: 0.60-1.22 AU) were significantly lower than in diabetic patients without nephropathy (1.19 AU, 0.90-1.38 AU, P = 0.01) and control subjects (0.82 AU, 0.60-1.22 AU vs 1.04 AU, 0.87-1.66, P = 0.02) while there was no difference between diabetic patients without nephropathy and control subjects (P = 0.69). Keap1 gene expression levels were almost identical in patients with and without diabetic nephropathy (1.15 AU, 0.63-2.14 AU vs 1.13 AU, 0.79-1.73 AU, P = 0.91) and higher than in control subjects (1.15 AU, 0.63-2.14 AU vs 0.79 AU, 0.49-1.08 AU, P = 0.046). MiRNA expression levels were comparable in diabetic patients with and without nephropathy, but miRNA 30e-5p was lower in patients with diabetic nephropathy than in diabetic patients without nephropathy (0.91 AU, 0.76-1.10 AU vs 1.06 AU, 0.89-1.23 AU, P = 0.016). The expression levels of Nrf2 and miRNA 30e-5p were unrelated in patients with (r = 0.15, P = 0.44) and without (r = -0.02, P = 0.90) diabetic nephropathy. In linear regression analyses, eGFR emerged as the first factor in rank for explaining the difference in Nrf2 mRNA levels (explained variance 76%) among patients with and without diabetic nephropathy. Conclusion This case-control study comparing the gene expression level of Nrf2 in diabetic patients with and without nephropathy shows that kidney dysfunction is the key factor that explains the variability in Nrf2 mRNA levels in diabetes. These data suggest a primary role of Nrf2 in redox homeostasis and kidney damage in diabetic nephropathy.

Raspberry Ketone Protects Kidney Damage in Diabetic Nephropathy by Improving Kidney Mitochondrial Dysfunction

Mitochondrial dysfunction and oxidative stress play essential roles in the pathogenesis of diabetic nephropathy (DN). The respiratory oxygen consumption and oxidative stress status of kidney mitochondria are closely associated with the development of DN. In this study, raspberry ketone (RK), the predominant bioactive component extracted from raspberry, was applied to treat the established DN mice model. This study investigated whether RK protects the kidneys of high-fat and high-sugar/streptozotocin (STZ)-induced diabetic rats by inhibiting oxidative stress and ameliorating mitochondrial dysfunction. Besides, the DN mice models were established by injecting high-fat and high-sugar/STZ (130 mg/kg, intraperitoneal injection). The animals were randomly divided into the control group (normal saline, ig), DN group (normal saline, ig), DN + RK group (200 mg/kg RK + normal saline, ig), DN + RK group (400 mg/kg RK + normal saline, ig), and DN + Metformin (Met) (200 mg/kg Met + normal saline, ig). Regular monitoring of fasting blood glucose (FBG) levels was observed in mice. After 10 weeks of drug treatment, the kidneys of mice in each group were analyzed using ultrasound, and the mice were euthanized humanely. Kidney weight (KW)/body weight (BW) and kidney injury, mitochondrial function, and oxidative stress indicators were determined. The histopathological changes in renal tissue were observed after hematoxylin and eosin (H&amp;E) staining. The results recommended that RK has a renoprotective function on DN mice by improving mitochondrial dysfunction and inhibiting oxidative stress.

Programmed Cell Death in Diabetic Nephropathy: A Review of Apoptosis, Autophagy, and Necroptosis.

Diabetic nephropathy is a common complication of type I and type II diabetes, in which renal glomeruli are destroyed, resulting in renal damage, proteinuria, and hypertension. Apoptosis, autophagy, and necroptosis are 3 forms of programmed cell death that have been implicated in the pathogenesis of diabetic nephropathy. Apoptosis of podocytes leads to glomerular injury and podocyte depletion, which are associated with proteinuria and glomerular structural damage in diabetic nephropathy. Additionally, epithelial cells in the proximal convoluted tubules also undergo apoptosis in diabetic nephropathy, leading to tubular atrophy, which causes tubular cell depletion and the subsequent formation of atubular glomeruli in association with the loss of renal function. On the other hand, insufficiency of autophagy has been correlated with the pathogenesis of diabetic nephropathy. For instance, decreased autophagic activity has been shown in podocytes of the diabetic kidney, causing variations in podocyte function and subsequent disruption to the glomerular filtration barrier. Furthermore, attenuated autophagic activity has also been demonstrated in proximal tubular cells of the diabetic kidney, resulting in the buildup of impaired molecules and organelles, which are normally broken down by autophagy, leading to proteinuria. Moreover, necroptosis might have a key role in podocyte damage and subsequent decline in diabetic nephropathy. Thus, this article aims to review the mechanisms and effects of programmed cell death in diabetic nephropathy, including the roles of apoptosis, autophagy, and necroptosis.

Formononetin Attenuates Renal Tubular Injury and Mitochondrial Damage in Diabetic Nephropathy Partly via Regulating Sirt1/PGC-1α Pathway.

Mitochondrial abnormality is one of the main factors of tubular injury in diabetic nephropathy (DN). Formononetin (FMN), a novel isoflavonoid isolated from Astragalus membranaceus, has diverse pharmacological activities. However, the beneficial effects of FMN on renal tubular impairment and mitochondrial dysfunction in DN have yet to be studied. In this study, we performed in vivo tests in Streptozotocin (STZ) -induced diabetic rats to explore the therapeutic effects of FMN on DN. We demonstrated that FMN could ameliorate albuminuria and renal histopathology. FMN attenuated renal tubular cells apoptosis, mitochondrial fragmentation and restored expression of mitochondrial dynamics-associated proteins, such as Drp1, Fis1 and Mfn2, as well as apoptosis-related proteins, such as Bax, Bcl-2 and cleaved-caspase-3. Moreover, FMN upregulated the protein expression of Sirt1 and PGC-1α in diabetic kidneys. In vitro studies further demonstrated that FMN could inhibit high glucose-induced apoptosis of HK-2 cells. FMN also reduced the production of mitochondrial superoxide and alleviated mitochondrial membrane potential (MMP) loss. Furthermore, FMN partially restored the protein expression of Drp1, Fis1 and Mfn2, Bax, Bcl-2, cleaved-caspase-3, Sirt1 and PGC-1α in HK-2 cells exposure to high glucose. In conclusion, FMN could attenuate renal tubular injury and mitochondrial damage in DN partly by regulating Sirt1/PGC-1α pathway.

Anti-Oxidative Therapy in Diabetic Nephropathy.

Chronic kidney disease is generally progressive and currently has no reliable treatment to reverse a decline in kidney function or to slow the progression of the disease. Diabetic nephropathy is one of the leading causes of end-stage kidney failure. Kidney damage in diabetic nephropathy is largely attributed to the increased oxidative stress, affecting its metabolic activity, metabolic pathways, and hemodynamic pathways. In diabetic patients, hyperglycemia causes an increase in the production of reactive oxygen species that further increase oxidative stress. These reactive oxygen species are created through a variety of pathways, providing the opportunity for treatment using anti-oxidative defense mechanisms to prevent vascular injury. This review will give an overview of oxidative stress, along with the current treatments and limitations of diabetic nephropathy. We will also discuss the potential of antioxidative therapies, with an emphasis on the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway.

Upregulation of TIPE1 in tubular epithelial cell aggravates diabetic nephropathy by disrupting PHB2 mediated mitophagy

Renal tubular epithelial cells (RTECs) are one of the most mitochondria-rich cell types, and are thus vulnerable to mitochondrial dysregulation, which is defined as a pivotal event in tubular damage in diabetic nephropathy (DN). However, the underlying mechanisms remain largely unknown. Here, we investigated the role and mechanisms of tumor necrosis factor alpha-induced protein 8-like 1 (TNFAIP8L1/TIPE1) in high glucose (HG)-induced mitochondrial dysfunction in RTECs and DN progression. TIPE1 expression was predominantly upregulated in RTECs in patients with DN and mice with streptozotocin (STZ)-induced DN. Conditional knockout of Tipe1 in RTECs significantly decreased the urine protein creatinine ratio, renal tubular damage, epithelial-mesenchymal transition, and interstitial fibrosis in STZ-induced mice. RNA sequencing revealed that citrate cycle-related genes were positively enriched in the renal tissues of RTEC-specific Tipe1 knockout mice. Tipe1 deficiency upregulated ATP levels, mitochondrial membrane potential, and respiration rate, but downregulated mitochondrial ROS levels in RTECs. Furthermore, Tipe1 ablation led to enhanced mitophagy in RTECs, indicative of increased LC3II, PINK1, and Parkin expression, but decreased p62 expression in mitochondria. Mechanistically, mass spectrometry screening and co-immunoprecipitation assays revealed the interaction of TIPE1 with prohibitin 2 (PHB2), a crucial mitophagy receptor. Intriguingly, TIPE1 promoted the ubiquitination and proteasomal degradation of PHB2. Subsequently, PHB2 knockdown almost abrogated the improvement of Tipe1 loss on HG-induced tubular cell mitophagy and damage. Thus, TIPE1 disrupts mitochondrial homeostasis in RTECs and promotes tubular damage by destabilizing PHB2 under HG conditions. Hence, TIPE1 may act as a potential therapeutic target to prevent DN progression.

Astragalus mongholicus Bunge and Panax notoginseng formula (A&P) improves renal mesangial cell damage in diabetic nephropathy by inhibiting the inflammatory response of infiltrated macrophages

BackgroundDiabetic nephropathy (DN) is one of the main causes of end-stage renal disease with scantly effective treatment. Numerous evidences indicated that macrophages play an important role in the occurrence and pathogenesis of DN by secreting inflammatory cytokines. Mincle is mainly expressed in macrophages and promotes kidney inflammation and damage of acute kidney injury. However, the role of Mincle in DN is unclear. In this study, we aim to investigate the effect of Mincle-related macrophage inflammation on DN, and whether it can be identified as the therapeutic target for Astragalus mongholicus Bunge and Panax notoginseng Formula (A&P), a widely used Chinese herbal decoction for DN treatment.MethodsIn vivo experiments high-fat and high-sugar diet and streptozotocin was used to establish a diabetic nephropathy model, while in vitro experiments inflammation model was induced by high-glucose in mouse Bone Marrow-Derived Macrophages (BMDM) cells and mouse mesangial (MES) cells. Kidney pathological staining is used to detect kidney tissue damage and inflammation, Western blotting, Real-time PCR and ELISA are performed to detect Mincle signaling pathway related proteins and inflammatory cytokines.ResultsMincle was mainly expressed in infiltrated macrophage of DN kidney, and was significant decreased after A&P administration. The in vitro experiments also proved that A&P effectively down-regulated the expression of Mincle in macrophage stimulated by high glucose. Meanwhile, the data demonstrated that A&P can reduce the activation of NFκB, and the expression and secretion of inflammatory cytokines in DN kidney or BMDM cells. Notably, we set up a co-culture system to conform that BMDM cells can aggravate the inflammatory response of mesangial (MES) cells under high glucose stimulation. Furthermore, we found that the anti-injury role of A&P in MES cells was dependent on inhibition of the Mincle in macrophage.ConclusionIn summary, our study found that A&P is effective in reducing renal pathological damage and improving renal function and inflammation in diabetic nephropathy by a mechanism mainly related to the inhibition of the Mincle/Card9/NFκB signaling pathway.

Reduced sRAGE Production and ADAM10 Gene Expression in Peripheral Blood Samples of Diabetic Nephropathy Patients

Introduction: Excessive signalling via the Receptor for Advanced Glycation End products (RAGE) is implicated in inflammatory renal damage in Diabetic Nephropathy (DN). RAGE signaling is modulated by its soluble form (sRAGE) that arises due to ectodomain cleavage catalysed by A Disintegrin and Metalloproteinase 10 (ADAM10). The sRAGE functions as a decoy and competes with RAGE for binding to the cognate ligand. Aim: The aim of this study was to evaluate sRAGE and ADAM10 gene levels in peripheral blood samples of Diabetic Nephropathy patients. Materials and Methods: The present observational study was conducted in the Department of General Medicine, RL Jalappa Hospital and Research Centre, Kolar, Karnataka, India, between January 2019 to April 2020. Study comprised of three groups: group 1 of 30 DN patients; group 2 of 28 Type II Diabetis Mellitus (T2DM) patients without microvascular complications and group 3 comprised of 30 healthy volunteers. Blood samples obtained from the study participants were cultured for 24 hours along with insulin treatment or a suitable control. sRAGE levels were measured in the conditioned media by Enzyme Linked Immunosorbent Assay (ELISA) technique. Expression of the ADAM10 gene was measured in the cell pellet by using the quantitative real-time Polymerase Chain Reaction (PCR) technique. Results: A total of 88 subjects were included in the study, with 30 patients in group 1 (DN, mean age 55.34±7.76 years), 28 patients in group 2 (T2DM, mean age: 55.07±7.7 years) and 30 subjects in group 3 (healthy individuals, mean age: 55±8.05 years). sRAGE levels were significantly lower in nephropathy patients when compared to healthy volunteers (p=2.5×10-9). Likewise, ADAM10 expression levels were also significantly lower in nephropathy patients when compared to healthy volunteers (p=1.3×10-4). Insulin treatment led to significantly higher sRAGE production in healthy volunteers as compared to T2DM patients (p-value 3.3×10-11). Insulin treatment leads to significant upregulation of the ADAM10 gene expression in healthy volunteers as compared to DN and T2DM. Conclusion: Abnormal RAGE signaling in DN may arise due to diminished sRAGE production as a consequence of reduced ADAM10 expression.

Long Non-Coding RNA Small Nucleolar RNA Host Gene 5 (SNHG5) Regulates Renal Tubular Damage in Diabetic Nephropathy via Targeting MiR-26a-5p.

The study explored the diagnostic value of SNHG5 in diabetic nephropathy (DN) and investigated the role and mechanism on DN via establishing the in vitro HK2 cell model. This study recruited 62 types 2 diabetes mellitus (T2DM) patients, 58 DN patients and 60 healthy controls (HC). The expressions of serum SNHG5 and miR-26a-5p were measured by RT-qPCR analysis. The diagnostic value of SNHG5 in DN was assessed by ROC curve. The in vitro cell model was built to estimate the effects of SNHG5 on cell viability, cell apoptosis, inflammation response and oxidative stress. Serum SNHG5 was increased in DN patients (relative expression: 2.04±0.34) and had the diagnostic value in DN. After HK2 cells were treated with high glucose, the cell viability decreased and apoptosis increased, and the production of inflammatory cytokines and ROS enhanced significantly. It was noticed that inhibition of SNHG5 could reverse the above phenomenon caused by high glucose. Besides, serum miR-26a-5p was diminished in DN patients, and luciferase reporter gene revealed that miR-26a-5p is direct target of SNHG5. These results indicated that inhibition of SNHG5 may mitigate HG-induced renal tubular damage via targeting miR-26a-5p, which providing a new insight into the mechanism of renal tubule damage in DN patients.

MiRNA-483-5p Targets HDCA4 to Regulate Renal Tubular Damage in Diabetic Nephropathy.

miRNA-483-5p Targets HDCA4 to Regulate Renal Tubular Damage in Diabetic Nephropathy.

414-P: Apparent Diffusion Coefficient on Diffusion-Weighted Magnetic Resonance Imaging Predicts the Progression of Renal Damage in Diabetic Nephropathy

Renal damage in diabetic nephropathy (DN) is evaluated by biochemical tests such as urine albumin-to-creatinine ratio (UACR) and serum estimated glomerular filtration rate (eGFR). On the other hand, renal biopsy, which is rich in definitive information, is rarely performed because of its complexity and high invasion. To evaluate whether diffusion-weighted magnetic resonance imaging (DW-MRI) could be a noninvasive approach for distinguishing DN, we performed MRI scanning of the subjects with 6 b-values (b = 0, 50, 100, 350, 400, 700) and analyzed the parameters using the kidney imaging software (Hitachi, Ltd., Tokyo). A total of 40 subjects were enrolled, 25 of whom had type 2 diabetes with or without hypertension (T2D), 9 had nondiabetes but hypertension (HT), and 6 were healthy volunteers (Control). T2D showed lower values of apparent diffusion coefficient (ADC) 0-700 compared with HT (129.0 ± 2.12 x10-5mm2/s in T2D vs. 132.5 ± 1.43 ×10-5mm2/s in HT, p&amp;lt;0.001). In addition, T2D with HT (n=15) had lower ADC0-700 compared with T2D without HT (n=10) (p &amp;lt; 0.01). Interestingly, T2D with non-DN nor HT presented lower ADC0-700 compared with HT (p&amp;lt;0.05). ADC0-700 in T2D were correlated with serum eGFR (r = 0.40, p &amp;lt;0.05) and inversely correlated with serum creatinine (r = - 0.40, p &amp;lt;0.05), cystatin C (r = - 0.54, p &amp;lt;0.01) and UACR (r = - 0.57, p &amp;lt;0.01). On the other hand, ADC0-700 in HT were not correlated with any of parameters of the renal function. Multivariate regression analysis with a stepwise forward method identified UACR as the only factor associated with the ADC0-700 values (β = - 0.68, p &amp;lt;0.001). Accumulating evidences show that lower levels of ADC on DW-MRI indicate greater fibrosis in various organs. Therefore, cortical ADC0-700 could predict the progression of the renal damage such as tubulointerstitial fibrosis. DW-MRI might provide a convenient diagnostic tool in the evaluation of DN. Disclosure H. Kitsunai: None. Y. Takiyama: Other Relationship; Self; Gilead Sciences, Inc., Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Mochida Pharmaceutical Co., Ltd., Roche Diabetes Care, Taisho Pharmaceutical Co., Ltd. N. Nakagawa: None. N. Hasebe: None. A. Okizaki: Research Support; Self; Fuji-Film Toyama Chemical Co., Ltd., Nihon Medhi-physics. M. Haneda: Advisory Panel; Self; Eli Lilly Japan K. K., Nippon Boehringer Ingelheim Co. Ltd., Novo Nordisk Inc. Funding Japan Society for the Promotion of Science (20K17420)

Metformin attenuates diabetic renal injury via the AMPK-autophagy axis.

Diabetic nephropathy (DN) is a clinical condition characterized by kidney damage that is observed in patients with diabetes. DN is the main cause of end-stage renal disease (ESRD), which is the final stage of chronic kidney disease. Increasing evidence suggests that metformin, a characteristic oral hypoglycemic drug used for treating diabetes, exerts beneficial effects on various medical conditions and diseases, including cancer, cardiovascular diseases and thyroid-related disorders. However, the impact of metformin on DN remains unknown. The present study investigated whether metformin could attenuate the inflammatory response, fibrosis and increased oxidative stress observed during DN in diabetic/dyslipidemic (db/db) mice. The kidneys of the mice (12-16 weeks) were isolated for immunohistochemistry and western blotting. The results demonstrated that metformin significantly reduced the oxidative damage and fibrosis in the kidneys of db/db mice. Furthermore, metformin treatment significantly inhibited the generation of inflammatory cytokines, including TNF-α and IL-1β in db/db mice. These effects were induced by the activation of the AMP-activated protein kinase (AMPK) pathway, which was mediated by increased phosphorylation of AMPK and mammalian target of rapamycin (mTOR), resulting in autophagy and the simultaneous decrease in reactive oxygen species production, cell apoptosis and inflammatory response. These findings suggested that metformin may reduce DN damage via regulation of the AMPK-mTOR-autophagy axis and indicated that metformin may be considered as a potential target in the treatment of DN.

Perilipin 5 ameliorates high-glucose-induced podocyte injury via Akt/GSK-3β/Nrf2-mediated suppression of apoptosis, oxidative stress, and inflammation

Hyperglycemia-induced podocyte damage contributes to the onset of diabetic nephropathy, a severe complication of diabetes. Perilipin 5 (Plin5) exerts a vital role in numerous pathological conditions via affecting cell apoptosis, oxidative stress, and inflammation. However, whether Plin5 plays a role in regulating podocyte damage of diabetic nephropathy has not been fully determined. This work aimed to explore the role of Plin5 in mediating high glucose (HG)-induced injury of podocytes in vitro. Our results demonstrated that Plin5 expression was markedly decreased in mouse podocytes challenged with HG. Plin5 overexpression markedly suppressed HG-induced apoptosis, reactive oxygen species (ROS) production, and the pro-inflammatory response in podocytes. On the contrary, Plin5 silencing produced the opposite effects. Further mechanistic analysis demonstrated that Plin5 upregulation remarkably increased the levels of phospho-Akt and phospho-glycogen synthase kinase-3β (GSK-3β) in HG-exposed podocytes. Moreover, Plin5 overexpression increased the levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and enhanced the activation of Nrf2 signaling. Akt inhibition markedly blocked Plin5-mediated activation of Nrf2, while GSK-3β inhibition reversed Plin5-silencing-induced suppressive effects on Nrf2 activation. Notably, Nrf2 suppression significantly blocked Plin5-mediated protective effects against HG-induced podocyte injury. In summary, our work indicates a vital role for Plin5 in protecting against HG-induced apoptosis, oxidative stress, and inflammation in podocytes via modulation of Akt/GSK-3β/Nrf2 signaling. This study suggests that Plin5 may participate in modulating podocyte damage in diabetic nephropathy.

Descurainia sophia Reduces Podocyte Damage in Diabetic Nephropathy by Down Regulating LncRNA KCNQ1OT1

Descurainia sophia Reduces Podocyte Damage in Diabetic Nephropathy by Down Regulating LncRNA KCNQ1OT1