Development Of Diabetic Nephropathy Research Articles

Role of Periostin and Nuclear Factor-κB Interplay in the Development of Diabetic Nephropathy.

Diabetic nephropathy (DN) remains the most common reason for end-stage renal disease and a leading cause of kidney replacement therapy. Multifactorial pathophysiological mechanisms underlie the development of DN. Among the signalling pathways involved, nuclear factor-κB (NF-κB) plays a key role in pathogenesis triggering inflammation, oxidative stress and fibrosis. Recent evidence shows that periostin, a matricellular protein, is involved in the development of renal glomerular diseases through interaction with NF-κB signalling. The aim of the present study is to investigate the contribution of periostin and its interaction with NF-κB in DN development. To this end, we used the BTBR ob/ob mice model of diabetes type 2, and we applied transcriptomic analysis, immunostaining and methods quantifying protein and mRNA expressions. We found that increased periostin expression was correlated with decreased renal function, advanced stage renal damage and fibrosis, and NF-κB activation. Subsequently, we identified novel pathways and genes regulated by the NF-κB-periostin interaction which are involved in the mechanisms of progression of DN. Some of these genes, such as FGF1 and GDF15, have the potential to be new biomarkers and/or targets for the therapy of DN.

ACE gene polymorphism and features of kidney disorders in patients with type 2 diabetes mellitus

Objective — to determine the prevalence of the Alu Ins/Del polymorphism of the angiotensin‑converting enzyme (ACE) gene in patients with type 2 diabetes mellitus (DM 2) with nephropathy and to identify possible associative relationship between the course of the disease and the genetic profile of the examined subjects.
 Materials and methods. Examinations involved 73 patients with diabetic nephropathy (DN), treated in the hospital of L. T. Mala Therapy National Institute. The control group consisted of 19 healthy individuals. After the initial examination and depending on the polymorphic variant of the ACE gene, patients were divided into three groups: group I — carriers of D/D polymorphism of the ACE gene (n = 23); group II — patients with I/D polymorphism of the ACE gene (n = 32); Group III — patients with I/I polymorphism of the ACE gene (n = 18). DNA amplification and genotyping were carried out by real‑time polymerase chain reaction (PCR) using the SNP‑Express‑Shot reagent kit (Litech, RF) and the CFX96 touch real‑time PCR product detection system (BioRad).
 Results. The distribution of the genotypes of the Alu I/D polymorphism of the ACE gene corresponded to the Hardy‑Weinberg equilibrium in all studied groups and did not differ significantly from European populations. Comparison of patients with DN, carriers of different Ins/Del polymorphic variants of the ACE gene, did not show significant differences in the stages of chronic kidney disease, creatinine level, and glomerular filtration rate (GFR). Patients with type 2 DM, homozygous for the I/I allele of the ACE gene, had significantly lower levels of urinary albumin (16.80 [12.61 — 34.20] mk/ mL), compared with I/D heterozygotes (26.07 [20.91 — 44.27] mkg/mL), p < 0.05, which demonstrates the negative effects of D allele on the kidney damage progression in this category of patients, even under the same GFR.
 Conclusions. Patients with DN who are homozygous for the ACE gene allele I, have significantly lower albumin levels than I/D heterozygotes, demonstrating an association between the D allele and the progression of renal disease in type 2 DM. Determining the ACE gene polymorphism in patients with type 2 DM allows to identify risk groups for the DN development and will help to make individualized adjustments to the scheme of pharmacological therapy.

Circ_0000064 knockdown attenuates high glucose-induced proliferation, inflammation and extracellular matrix deposition of mesangial cells through miR-424-5p-mediated WNT2B inhibition in cell models of diabetic nephropathy.

Circular RNA (circRNA) is widely shown to be associated with the development of diabetic nephropathy (DN). Our study aimed to further explore the role of circ_0000064 and provide a new mechanism for its action in DN. Cell models of DN in vitro were constructed by treating human renal mesangial cells (HRMCs) with high glucose (HG). The expression of circ_0000064, microRNA-424-5p (miR-424-5p) and Wnt family member 2B (WNT2B) mRNA was detected by quantitative real-time PCR (qPCR). Cell proliferation was assessed by CCK-8 assay and EdU assay. Cell cycle was characterized by DNA content using flow cytometry. The releases of pro-inflammatory factors were checked using commercial ELISA kits. The expression of cell cycle- and fibrosis-associated proteins was detected by western blot. The interplays between miR-424-5p and circ_0000064 or WNT2B were verified by dual-luciferase reporter assay and RIP assay. Circ_0000064 and WNT2B were upregulated, while miR-424-5p was downregulated in HG-treated HRMCs. Circ_0000064 knockdown largely attenuated HG-induced proliferation, inflammatory responses and extracellular matrix (ECM) accumulation in HRMCs, and miR-424-5p deficiency reversed the role of circ_0000064 knockdown. MiR-424-5p was a target of circ_0000064, and miR-424-5p directly bound to WNT2B. MiR-424-5p restoration alleviated HG-induced proliferation, inflammatory responses and ECM accumulation in HRMCs, and WNT2B overexpression partially abolished the effects of miR-424-5p. Circ_0000064 knockdown ameliorated HG-induced HRMC dysfunctions through miR-424-5p enrichment-mediated WNT2B inhibition, hinting that circ_0000064 contributed to DN development.

Mechanistic Pathogenesis of Endothelial Dysfunction in Diabetic Nephropathy and Retinopathy.

Diabetic nephropathy (DN) and diabetic retinopathy (DR) are microvascular complications of diabetes. Microvascular endothelial cells are thought to be the major targets of hyperglycemic injury. In diabetic microvasculature, the intracellular hyperglycemia causes damages to the vascular endothelium, via multiple pathophysiological process consist of inflammation, endothelial cell crosstalk with podocytes/pericytes and exosomes. In addition, DN and DR diseases development are involved in several critical regulators including the cell adhesion molecules (CAMs), the vascular endothelial growth factor (VEGF) family and the Notch signal. The present review attempts to gain a deeper understanding of the pathogenesis complexities underlying the endothelial dysfunction in diabetes diabetic and retinopathy, contributing to the development of new mechanistic therapeutic strategies against diabetes-induced microvascular endothelial dysfunction.

Role of Polyphenol in Regulating Oxidative Stress, Inflammation, Fibrosis, and Apoptosis in Diabetic Nephropathy.

Diabetic Nephropathy (DN) is known as one of the driving sources of End-Stage Renal Disease (ESRD). DN prevalence continues to increase in every corner of the world andthat has been a major concern to healthcare professionals as DN is the key driver of Diabetes Mellitus (DM) morbidity and mortality. Hyperglycaemia is closely connected with the production of Reactive Oxygen Species (ROS) that cause oxidative stress response as well as numerous cellular and molecular modifications. Oxidative stress is a significant causative factor to renal damage, as it can activate other immunological pathways, such as inflammatory, fibrosis, and apoptosis pathways. These pathways can lead to cellular impairment and death as well as cellular senescence. Natural substances containing bioactive compounds, such as polyphenols, have been reported to exert valuable effects on various pathological conditions, including DM. The role of polyphenols in alleviating DN conditions has been documented in many studies. In this review, the potential of polyphenols in ameliorating the progression of DN via modulation of oxidative stress, inflammation, fibrosis, and apoptosis, as well as cellular senescence, has been addressed. This information may be used as the strategies for the management of DN and development as nutraceutical products to overcome DN development.

IDF21-0282 Association between Serum Uric Acid and Renal Outcome in Patients with Biopsy-confirmed Diabetic Nephropathy

Background: It is well established that diabetic nephropathy (DN) is the first cause of end-stage renal disease (ESRD) in developed and developing countries. Serum uric acid (SUA) level has been widely recognized as a risk factor for DN development because oxidants are produced that can play a key role in renal injury during UA synthesis. Recently, a randomized, controlled trial (RCT) showed that in Multi-ethnic patients with a high risk of progression and stage 3-4 CKD in Australia and New Zealand, SUA lowering treatment using allopurinol could not significantly attenuate the drop of eGFR as compared with placebo, which is somewhat intriguing. Therefore, the association between SUA and renal outcome in type 2 diabetes mellitus (T2DM) and DN patients remains to be elucidated in more detail. Aim: To investigate the relationship between SUA level and renal outcome in patients with T2DM and diabetic nephropathy (DN). Method: A total of 393 Chinese patients with T2DM and biopsy-proven DN and followed at least one year were enrolled in this study. Patients were stratified by the quartiles of baseline level of SUA: Q1 group286.02± 46.66 μmol/L (n=98); Q2 group: 358.23±14.03 μmol/L (n=99); Q3 group: 405.50±14.59 μmol/L (n=98) and Q4 group: 499.14±56.97 μmol/L (n=98). Renal outcome was defined by progression to end stage renal disease (ESRD). Kaplan-Meier survival analysis and Cox proportional hazards model were used to analyze the association between SUA quartiles and the renal outcomes. Results: During the median 3-year follow-up period, there were 173 ESRD outcome events (44.02%) during follow-up. No significant difference among SUA level the risk of progression of DN (P=0.747) was shown in the Kaplan-Meier survival analysis. In multivariable-adjusted model, HRs for developing ESRD were 1.364(0.621-2.992; p=0.439), 1.518(0.768-3.002; p=0.230) and 1.411(0.706-2.821; p=0.330) for the Q2, Q3 and Q4, respectively, in comparison with the Q1 (P=0.652). Discussion: No significant association between SUA level and renal outcome of ESRD in Chinese patients with T2DM and DN was found in our study. Besides, the role of uric acid-lowering therapy in delaying DN progression and improve ESRD outcome had not yet been proven. Further study was needed to clarify the renal benefit of the uric acid-lowering therapy in the treatment of DN.

Transcriptome expression profiles associated with diabetic nephropathy development

The objective of this study was to identify different transcriptome expression profiles involved in the pathogenesis of diabetic nephropathy (DN) and to illustrate the diagnostic and therapeutic potential of mRNAs, long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) in DN progression. The participants were divided into four groups: normoalbuminuria (group DM), microalbuminuria (group A2), macroalbuminuria (group A3) and healthy controls (group N). There were three individuals in each group for sequencing. Transcriptome sequencing analysis was performed on the peripheral blood of all the participants to identify the differential expression of mRNAs, lncRNAs, and circRNAs between intervention groups and controls. The functional enrichment analysis, the short time-series expression miner (STEM) program, and the miRNA-circRNA-mRNA network were further conducted. To verify the reproducibility of transcriptome sequencing, 10 and 30 blood samples were collected from the control and diseased groups, respectively. Four candidate biomarkers were selected from differentially expressed circRNAs (circ_0005379, circ_0002024, and circ_0000567, and circ_0001017) and their concentrations in the blood were measured using quantitative PCR (qPCR). In the comparison of A2 with N, 549 mRNAs, 1259 lncRNAs, and 12 circRNAs were screened. In the comparison of A3 with N, 1217 mRNAs, 1613 lncRNAs, and 24 circRNAs were screened. Moreover, in the comparison of diabetes mellitus (DM) with N, 948 mRNAs, 1495 lncRNAs, and 25 circRNAs were screened. Functional enrichment analysis showed that differentially expressed mRNAs were related to insulin secretion, insulin resistance, and inflammation, while differentially expressed lncRNAs were mainly associated with crossover junction endodeoxyribonuclease activity. In STEM analysis, a total of 481 mRNAs and 152 differential expression circRNAs showed a significant tendency. The key relationships in the miRNA-circRNA-mRNA network were identified, such as hsa-miR-103a-3p-circ_0005379-PTEN, hsa-miR-497-5p-circ_0002024-IGF1R and hsa-miR-1269a-circ_0000567-SOX6. In addition, qPCR showed consistent results with RNA sequencing. We found that differentially expressed mRNAs, lncRNAs, and circRNAs participated in DN development. Circ_0005379, circ_0002024, and circ_0000567 could be adopted as potential biomarkers for DN.

Heparanase promotes endothelial-to-mesenchymal transition in diabetic glomerular endothelial cells through mediating ERK signaling

Glomerular endothelial cells (GEnCs) dysfunction occurs at the early stage of diabetic nephropathy (DN). One of its characteristics is endothelial-to-mesenchymal transition (EndMT). Heparanase (HPSE) is the only known mammalian endoglycosidase capable of degrading heparin sulfates and has a prominent role in DN pathogenesis. However, whether HPSE induces EndMT of GEnCs remains unknown. This study aimed to determine the effect and potential mechanism of HPSE on GEnCs phenotype under high-glucose conditions. In the early development of streptozotocin (STZ)-induced diabetic mice, HPSE overexpression was positively correlated with renal injury and the number of GEnCs undergoing EndMT, which was characterized by loss of endothelial marker CD31 and gain of mesenchymal markers including α-SMA and Snail1/2 by double immunofluorescence staining. Bioinformatics analysis revealed a positive correlation between HPSE and ERK. The counts of double positive staining of CD31 and p-ERK1/2 was significantly increased in the glomeruli of STZ-induced diabetic mice compared with sham mice. In cultured GEnCs, high glucose dramatically upregulated the expressions of HPSE and p-ERK1/2, both of which were markedly blocked by HPSE siRNA. Furthermore, recombinant mouse HPSE (rmHPSE) promoted the expressions of mesenchymal markers and p-ERK1/2 in a dosage- and time-dependent manner. U0126, a specific MEK/ERK inhibitor, significantly inhibited either high glucose or rmHPSE-induced EndMT of GEnCs. These data indicate that high glucose induces EndMT of GEnCs at least partially through upregulating HPSE and that HPSE promotes EndMT of GEnCs via activating ERK signaling. This study improves understanding the crucial role of HPSE in DN development and progression.

Disrupting circ-GNB4 mitigates high glucose-induced human mesangial cells injury by regulating the proliferation, ECM accumulation, inflammation and oxidative stress through circ-GNB4/miR-23c/EGR1 pathway [RETRACTED

Diabetic nephropathy (DN) is the most common complication of diabetes mellitus. Although G protein subunit beta 4 (GNB4)-derived circular RNA (circ-GNB4; hsa_circ_0068087) is a promising candidate biomarker in diabetes mellitus, whether circ-GNB4 participates in DN occurrence and development remains unknown. Herein, we focused on DN-associated human renal mesangial cells (HRMCs) injury, and HRMCs were exposed in high glucose (HG) condition. Using quantitative polymerase chain reaction and western blotting, we found that circ-GNB4 and early growth response factor 1 (EGR1) were upregulated, whereas microRNA (miR)-23c was downregulated in DN patients' sera and HG-stimulated HRMCs. HG-induced injuries were measured by MTS method, western blotting, enzyme-linked immunosorbent assay and other special assay kits. Consequently, HG could inhibit superoxide dismutase activity, but induce cell proliferation and levels of malondialdehyde, Fibronectin, Collagen I, Collagen IV, interleukin-6, interleukin-1β, and tumor necrosis factor-α. However, HG-induced these injuries were overall suppressed by silencing circ-GNB4 or overexpressing miR-23c. Moreover, miR-23c knockdown could counteract the effect of circ-GNB4 deficiency, and EGR1 restoration abrogated miR-23c overexpression role in HG-stimulated HRMCs. Notably, circ-GNB4 could target miR-23c and EGR1 was targeted by miR-23c, as confirmed by dual-luciferase reporter assay and RNA immunoprecipitation. Moreover, EGR1 expression was positively modulated by circ-GNB4 via miR-23c. Collectively, circ-GNB4 might be a novel mechanism of DN-induced HRMCs injury, and there was a circ-GNB4/miR-23c/EGR1 pathway underlying the proliferation, extracellular matrix accumulation, inflammation and oxidative stress. This study suggested circ-GNB4 as a potential target to interfere the development of DN.

TLR9 regulates NLRP3 inflammasome activation via the NF-kB signaling pathway in diabetic nephropathy

BackgroundToll-like receptors (TLRs) are critical sensors for the conservation of bacterial molecules and play a key role in host defense against pathogens. The effect of TLRs on the maintenance of diabetic nephropathy (DN) and resistance to infection has been investigated; however, the detailed effects of TLR9 on DN development remain elusive.MethodsWe performed quantitative reverse transcription-polymerase chain reaction and western blotting to detect TLR9 expression levels in the kidneys of experimental mice (db/db) and high-glucose-treated mouse mesangial cell strains (MCs).ResultsTLR9 expression was found to be remarkably upregulated in the kidneys of experimental mice (db/db) and MCs cultivated under hyperglycemic conditions. Moreover, knockdown of TLR9 could restrain NF-kB viability and downregulate the NLRP3 inflammasome in high glucose-treated MCs. TLR9 inhibition also alleviated inflammation and apoptosis, which was reversed by the addition of the NF-κB activator, betulinic acid. Furthermore, depleted TLR9 levels restrained NF-κB viability and NLRP3 expression and reduced kidney inflammation, microalbuminuria discharge, blood sugar level, and glomerular damage in experimental mice (db/db) kidneys. ConclusionsThese findings offer novel insights into the regulation of TLR9 via the nuclear factor-kB/NOD-, LRR-, and pyrin domain-containing protein 3 inflammasome inflammation pathways in DN progression.

Serum Amyloid A3 Promoter-Driven Luciferase Activity Enables Visualization of Diabetic Kidney Disease.

The early detection of diabetic nephropathy (DN) in mice is necessary for the development of drugs and functional foods. The purpose of this study was to identify genes that are significantly upregulated in the early stage of DN progression and develop a novel model to non-invasively monitor disease progression within living animals using in vivo imaging technology. Streptozotocin (STZ) treatment has been widely used as a DN model; however, it also exhibits direct cytotoxicity to the kidneys. As it is important to distinguish between DN-related and STZ-induced nephropathy, in this study, we compared renal responses induced by the diabetic milieu with two types of STZ models: multiple low-dose STZ injections with a high-fat diet and two moderate-dose STZ injections to induce DN. We found 221 genes whose expression was significantly altered during DN development in both models and identified serum amyloid A3 (Saa3) as a candidate gene. Next, we applied the Saa3 promoter-driven luciferase reporter (Saa3-promoter luc mice) to these two STZ models and performed in vivo bioluminescent imaging to monitor the progression of renal pathology. In this study, to further exclude the possibility that the in vivo bioluminescence signal is related to renal cytotoxicity by STZ treatment, we injected insulin into Saa3-promoter luc mice and showed that insulin treatment could downregulate renal inflammatory responses with a decreased signal intensity of in vivo bioluminescence imaging. These results strongly suggest that Saa3 promoter activity is a potent non-invasive indicator that can be used to monitor DN progression and explore therapeutic agents and functional foods.

The Wnt Signaling Pathway in Diabetic Nephropathy.

Diabetic nephropathy (DN) is a serious kidney-related complication of both type 1 and type 2 diabetes mellitus (T1DM, T2DM) and the second major cause of end-stage kidney disease. DN can lead to hypertension, edema, and proteinuria. In some cases, DN can even progress to kidney failure, a life-threatening condition. The precise etiology and pathogenesis of DN remain unknown, although multiple factors are believed to be involved. The main pathological manifestations of DN include mesangial expansion, thickening of the glomerular basement membrane, and podocyte injury. Eventually, these pathological manifestations will lead to glomerulosclerosis, thus affecting renal function. There is an urgent need to develop new strategies for the prevention and treatment of DN. Existing evidence shows that the Wnt signaling cascade plays a key role in regulating the development of DN. Previous studies focused on the role of the Wnt canonical signaling pathway in DN. Subsequently, accumulated evidence on the mechanism of the Wnt non-canonical signaling indicated that Wnt/Ca2+ and Wnt/PCP also have essential roles in the progression of DN. In this review, we summarize the specific mechanisms of Wnt signaling in the occurrence and development of DN in podocyte injury, mesangial cell injury, and renal fibrosis. Also, to elucidate the significance of the Wnt canonical pathway in the process of DN, we uncovered evidence supporting that both Wnt/PCP and Wnt/Ca2+ signaling are critical for DN development.

Kruppel Like Factor 5 Enhances High Glucose-Induced Renal Tubular Epithelial Cell Transdifferentiation in Diabetic Nephropathy.

Background - Diabetic nephropathy (DN) is a principal reason for kidney disease worldwide. High glucose (HG) is a major factor for DN. Kruppel like factor 5 (KLF5) participates in DN development. In the present study, we aim to elaborate the role of KLF5 in HG-induced renal tubular epithelial cell (RTEC) transdifferentiation in DN. Methods - RTECs (HK-2 cells) were treated with HG and were transfected with si-KLF5 or oe-HMGB1. Afterwards, expression of KLF5 and HMGB1 was detected, HK cell viability was determined, and levels of alpha-smooth muscle actin (α-SMA), E-cadherin, vimentin, and transforming growth factor beta 1 (TGF-β1) were assessed. Additionally, the binding relation between KLF5 and HMGB1 was analyzed. Results - In HK-2 cells with HG treatment, expression of KLF5 and HMGB1 was upregulated; levels of α-SMA, vimentin, and TGF-β1 were increased; and E-cadherin level was decreased. Moreover, KLF5 silencing resulted in down-regulated levels of α-SMA, vimentin, and TGF-β1 but upregulated level of E-cadherin. On the other hand, KLF5 could bind to the HMGB1 promoter and activate HMGB1 transcription. HMGB1 overexpression partially counteracted the inhibitive effect of KLF5 silencing on HG-induced HK-2 transdifferentiation. Conclusion - HG induced overexpressed KLF5 in RTECs, and as a transcription factor, KLF5 could bind to the HMGB1 promoter, thereby promoting HMGB1 transcription and RTEC transdifferentiation.

Serpin Family E Member 1 Tag Single-Nucleotide Polymorphisms in Patients with Diabetic Nephropathy: An Association Study and Meta-Analysis Using a Genetic Model-Free Approach.

Background: Many lines of evidence highlight the genetic contribution on the development of diabetic nephropathy (DN). One of the studied genes is SERPINE1 whose the role in the risk of developing DN remains questionable. In order to elucidate the contribution of SERPINE1 in DN progression in the context of type 2 diabetes mellitus (T2DM), we conducted an association study and meta-analysis of SERPINE1 genetic variants. Materials and Methods: A total of 190 patients with DN, 150 T2DM (type 2 diabetes mellitus) patients without DN and 238 healthy controls were recruited. We selected five tag single-nucleotide polymorphisms (SNPs) from the HapMap. The generalized odds ratio (ORG) was calculated to estimate the risk on DN development. Subgroup analyses based on ethnicity and type of diabetes were also performed. Results: Both the present association study regarding SERPINE1 SNPs (rs2227667, rs2070682, rs1050813, rs2227690, rs2227692) did not found any significant association between SERPINE1 variants and DN and the meta-analysis of variant 4G>5G (rs1799889) did not also reveal a significant association between 4G>5G variant and DN in main and subgroup analyses. Discussion: In conclusion, the present association study and meta-analysis provides strong evidence that SERPINE1 genetic variant 4G>5G is not implicated in the risk or development of DN in Caucasians. Further studies in other populations remain to further investigate the role of this variant in the course of DN.

Levels of fibroblast growth factor 23 in patients with diabetic nephropathy and its prognostic role in the development of kidney damage

Objective — to define levels of fibroblast growth factor 23 (FGF‑23) in the blood serum of patients with diabetic nephropathy (DN) combined with primary hypertension and investigate its prognostic role in the progression of kidney damage.
 Materials and methods. Examinations involved 86 patients with DN combined with primary hypertension (PH), 29 patients with PH and 30 healthy subjects (control group). Glomerular filtration rate was calculated with CKD‑EPI formula (KDIGO 2012). Blood serum levels of FGF‑23 were determined by ELISA, and calcium and phosphorus levels — with the use of reagents kit «Cormay» (Poland). Prognostic role of FGF‑23 was assessed with ROC‑analysis.
 Results. It has been established that FGF‑23 level in patients with DN and PH was higher than in patients with PH only (р < 0.001) and practically healthy subjects (р < 0.001). Patients with comorbid pathology demonstrated progressive augmentation of the FGF‑23 levels depending on the disease stage. The highest FGF‑23 level was revealed in patients with IV stage DN and PH. In patients with DN and PH, the correlation has been established between FGF‑23 levels and calcium and phosphorus levels and indices of the functional kidney state. The data have been obtained regarding prognostic FGF‑23 role at DN and PH comorbidity. The blood serum FGF‑23 level, prognostically unfavorable for the DN development, has been established.
 Conclusions. The obtained results showed the advisability to assess the serum blood FGF‑23 levels in patients with diabetic nephropathy as an early diagnostic marker of mineral disorders and prognosis for nephropathy development.

XCL1 Aggravates Diabetic Nephropathy-Mediated Renal Glomerular Endothelial Cell Apoptosis and Inflammatory Response via Regulating p53/Nuclear Factor-Kappa B Pathway

Background: Glomerular endothelial cell damage plays an important role in the occurrence and development of diabetic nephropathy (DN). Objectives: This study aimed to clarify the role of XCL1 in DN-mediated glomerular endothelial cell apoptosis and whether the function was related to the activation of the p53/nuclear factor-kappa B (NF-κB) signaling pathway. Methods: Candidate biomarkers were identified by least absolute shrinkage and selection operator (LASSO) regression model analysis. The area under the receiver operating characteristic curve value was calculated and used to evaluate the discriminating ability. Cell viability, apoptosis, and interleukin-1β and tumor necrosis factor-α expression at messenger RNA and protein levels were detected by using the Cell Counting Kit-8, flow cytometry, ELISA, real-time polymerase chain reaction, and Western blotting assays. In vivo studies were conducted in the DN mice. Results: The LASSO regression model displayed good discriminating performance, with a C-index of 0.803 and good calibration, and high XCL1 expression was identified as the predicting factor for DN in diabetes mellitus patients. XCL1 expression was upregulated in glomeruli of db/db mice, which was closely related to the expression of its receptor (XCR1). XCL1 overexpression played an important role in the apoptosis and inflammatory response of high glucose (HG)-treated human renal glomerular endothelial cells. Meanwhile, the expression of p53 and the levels of inflammatory cytokines were upregulated upon XCL1 overexpression. p53 silencing with its inhibitor blocked the apoptotic response and inflammatory response in XCL1-overexpressed cells exposed to HG. Besides, the XCL1 overexpression-induced downregulation of NF-κB was reversed by pifithrin-α pretreatment. Conclusions: Our findings in this work provided the mechanistic insights into the effects of XCL1 on the modulation of DN development, illustrating that XCL1 might serve as an essential prognostic indicator and therapeutic target for DN progression.

Advanced Glycation End Products and Malondialdehyde Serum Level Association with Nephropathy in Type Two Diabetic Patients

Aim of the Study: Evaluate the relation of serum level of AGEs and MDA with the development ofdiabetic nephropathy in patient with type two diabetes mellitus and to evaluate the possible mechanismby which AGEs and MDA induce nephrotic complication in type two diabetic patients.Patients and Methods: This case-control study was carried out in Erbil city from the period startedfrom 1st of December 2020 to the end of March 2021. The study included 62 type 2 diabetic patients(31 patients nephropathy and 31 patients T2DM without nephropathy), their age between 40– 69 years,these patients who attended Rizgari General Hospital. The study also included 28 healthy controlindividuals defended as subjects who apparently haven’t any chronic diseases. Blood was collectedfrom each for determination of HbA1c level , AGE3 and MDA and RBS.Results: The study revealed that, the highest mean of RBS and HbA1c was recorded in DN groupfollowed by diabetic non-nephropathy and the control group. The study revealed that, the highest meanof UACR was recorded in DN group (258.6±28.56 mg/gm) followed by diabetic non-nephropathy(35.6±11.95 mg/gm) and the control group (20.39±1.72 mg/gm) (P<0.001). The study showed asignificant positive of AGEs and MDA with each of duration of DM, blood sugar, HbA1c and UACR.Conclusions: This study showed elevated of AGEs, MDA and Poor glycemic control were associatedwith diabetic nephropathy.

FOXA1 Suppresses SATB1 Transcription and Inactivates the Wnt/β-Catenin Pathway to Alleviate Diabetic Nephropathy in a Mouse Model.

ObjectiveDiabetic nephropathy (DN) represents the most common diabetic complication that may lead to end-stage renal disease. This work focused on the effect of FOXA1 on the DN development and the molecular mechanism.MethodsA mouse model of DN was induced by high-fat diets and streptozotocin. The concentrations of blood glucose and urinary protein in mice, and the pathological changes in mouse kidney tissues were determined. A podocyte cell line MPC-5 was treated with high glucose (HG) to mimic a DN-like condition in vitro. FOXA1 and SATB1 were overexpressed in HG-treated MPC-5 cells and in DN mice to explore their effects on cell proliferation and apoptosis, and on pathological changes in mouse kidney tissues. The binding relationship between FOXA1 and STAB1 was predicted and validated. Activation of the Wnt/β-catenin pathway was detected.ResultsFOXA1 was poorly expressed in the kidney tissues of DN mice. Overexpression of FOXA1 reduced the concentrations of fasting blood glucose and 24-h urinary protein in mice. It also suppressed the accumulation of glomerular mesangial matrix and hyperplasia of glomerular basement membrane, and reduced collagen deposition and interstitial fibrosis in mouse kidney. Also, FOXA1 reduced HG-induced apoptosis of MPC-5 cells. FOXA1 bound to the promoter region of SATB1 for transcription suppression. Overexpression of SATB1 activated the Wnt/β-catenin pathway and blocked the protective roles of FOXA1 in DN mice and in HG-treated MPC-5 cells.ConclusionThis study demonstrated that FOXA1 transcriptionally suppresses SATB1 expression and inactivates the Wnt/β-catenin signaling pathway, thereby inhibiting podocyte apoptosis and DN progression.

Dietary protein sources and risk of diabetic nephropathy in women: A case-control study

BackgroundSeveral studies have investigated the association between dietary protein and the risk of diabetic nephropathy (DN); however, there is no agreement on the type of dietary protein sources that might increase the risk of DN. This study was conducted to investigate the associations between different protein sources and the odds of DN developing in Iranian women with existing type 2 diabetes.MethodsIn this case-control study, 105 women with DN and 105 controls, matched for age and diabetes duration, were selected from the Kowsar Diabetes Clinic in Semnan, Iran. Dietary intake was assessed using a validated and reliable food frequency questionnaire. Dietary protein patterns were estimated using the factor analysis method. Multivariate logistic regression was performed to examine the association between protein patterns and the odds of developing DN.ResultsTwo patterns were identified: the Mediterranean-based Dietary Protein Sources (MDPS) pattern which is rich in low-fat dairy, fish, poultry, soy, and legumes, and the Western-based Dietary Protein Sources (WDPS) pattern, rich in red and processed meats, eggs, and high-fat dairy. After adjusting for several confounders, greater adherence (third vs. the first tertile) to the MDPS pattern was associated with lower odds of DN (OR = 0.03; 95 % CI: 0.00, 0.10). In contrast, a strong positive association was observed between adherence to the WDPS pattern and DN (OR = 2.81; 95 % CI: 1.09–7.21).ConclusionsOur results show that there is a potential association between the type of protein sources consumed and the odds of DN development in women with type 2 diabetes. Further studies are needed to confirm these findings.

Ipragliflozin Ameliorates Diabetic Nephropathy Associated with Perirenal Adipose Expansion in Mice.

Sodium glucose cotransporter-2 (SGLT2) inhibitors inhibit the development of diabetic nephropathy (DN). We determined whether changes in perirenal fat (PRAT) by a SGLT2 inhibitor ipragliflozin (Ipra) contribute to the suppression of DN development. High-fat diet (HFD)-fed mice were used as a DN model and were treated with or without Ipra for 6 weeks. Ipra treatment reduced urinary albumin excretion (UAE) and glomerular hypertrophy in HFD-fed mice. In the PRAT of Ipra-treated mice, adipocyte size was increased, and inflammation, fibrosis, and adipocyte death were suppressed. In conditioned medium made from PRAT (PRAT-CM) of Ipra-treated mice, the concentration of leptin was significantly lower than PRAT-CM of mice without Ipra treatment. Serum leptin concentration in renal vein positively correlated with UAE. PRAT-CM from HFD-fed mice showed greater cell proliferation signaling in mouse glomerular endothelial cells (GECs) than PRAT-CM from standard diet-fed mice via p38MAPK and leptin-dependent pathways, whose effects were significantly attenuated in PRAT-CM from Ipra-treated mice. These findings suggest that Ipra-induced PRAT expansion may play an important role in the improvement of DN in HFD-fed mice. In vitro experiments suggest that reduced PRAT-derived leptin by Ipra could inhibit GECs proliferation, possibly contributing to the suppression of DN development.