Diabetic nephropathy as the cause of end-stage kidney disease reported on the medical evidence form CMS2728 at a single center

Sodium butyrate improves mitochondrial function and kidney tissue injury in diabetic kidney disease via the AMPK/PGC-1α pathway

PURPOSE

Investigate the mechanism of how sodium butyrate (NaBut) improves mitochondrial function and kidney tissue injury in diabetic kidney disease (DKD) via the AMPK/PGC-1α pathway.

METHODS

Assess the effects of NaBut on glucose and insulin tolerance, urine, and gut microbial composition in db/db and db/m mice. Use flow cytometry and western blotting to detect the effects of NaBut on apoptosis, kidney mitochondrial function, and AMPK/PGC-1α signaling. Use HK-2 cells induced by high glucose (HG) to establish the DKD model in vitro and detect changes in the AMPK/PGC-1α signaling pathway and mitochondrial function after NaBut intervention.

RESULTS

NaBut attenuated blood glucose levels and reversed increases in urine and serum levels of glucose, BUN, Ucr, TG, TC, and UAE in db/db mice. NaBut improved insulin tolerance, reversed PGC-1α and p-AMPK expression level in the kidneys of db/db mice, and improved lipid accumulation and mitochondrial function. NaBut was able to reverse the effects of elevated glucose, compound C, and siRNA-PGC on ROS and ATP levels. Additionally, it increased protein expression of PGC-1α and p-AMPK.

CONCLUSION

NaBut activates the kidney mitochondrial AMPK/PGC-1α signaling pathway and improves mitochondrial dysfunction in DKD, thus protecting kidney tissue in vitro and in vivo.

[Carnosine protects against diabetic nephropathy in rats by activating the AKT/mTOR pathway and restoring autophagy in the renal tissue]

OBJECTIVE

To explore the mechanisms mediating the protective effect of carnosine against nephropathy in rats with diabetes mellitus (DM).

METHODS

Rat models of DM established by high-fat diet feeding and streptozotocin injection were randomized into DM group and 3 treatment groups with daily carnosine treatment at 100, 300, and 900 mg/kg. Body weight and blood glucose level changes of the rats were measured regularly. After the treatment, 24-h urine, serum samples and kidneys of the rats were collected to measure urine volume, urine protein content, blood creatinine, and kidney mass; renal pathology was observed using HE staining, and MDA content and SOD activity in the kidney tissues were detected. Western blotting was performed to detect the protein expressions of p-AKT, AKT, p-mTOR, mTOR, LC3 and p62 in the kidney tissues.

RESULTS

Compared with normal control rats, the diabetic rats exhibited dull and wet hair and showed decreased body weight, increased blood glucose, urinary protein content, 24-h urine volume, blood creatinine, and kidney mass with obvious swelling and deformation of the glomeruli, narrowing of the renal tubules, decreased SOD activity and increased MDA content, lowered p-mTOR/mTOR and p-AKT/AKT ratios and increased LC3 Ⅱ/Ⅰ ratio and p62 protein expression in the kidney tissue. The diabetic rats receiving carnosine treatments had dry hair with normal luster and showed increased body weight and slightly decreased blood glucose, urinary protein content, 24-h urine volume, blood creatinine, and kidney mass. The treatment also improved renal pathology, increased SOD activity, decreased MDA content, increased p-mTOR/mTOR and p-AKT/AKT ratios and lowered LC3 Ⅱ/Ⅰ ratio and p62 protein expression in renal tissue of the diabetic rats.

CONCLUSION

Carnosine offers protection against nephropathy in rats with DM possibly by inhibiting oxidative stress, activating the AKT/mTOR pathway, and restoring autophagy in the kidneys.

Global burden and influencing factors of chronic kidney disease due to type 2 diabetes in adults aged 20-59 years, 1990-2019

Population structure and lifestyles may have contributed to the epidemiological status of Chronic Kidney Disease due to Type 2 Diabetes (CKD-T2D). This study is a secondary data analysis. Using data from the Global Burden of Disease Study, we describe the changes in CKD-T2D burden and its influencing factors in the population aged 20-59 years from 1990 to 2019. Globally, the incidence, death, and Disability Adjusted Life Years (DALYs) rate of CKD-T2D showed an upward trend and increased with age, and the burden in males was higher than that in females. Population growth and aging were important driving factors for the increase of CKD-T2D DALY burden, while high systolic blood pressure and high body-mass index were the primary attributable risk factors. High body-mass index exhibited higher contributions to high Socioeconomic Development Index (SDI) countries, whereas low SDI countries were more impacted by high systolic blood pressure. The population attributable fraction of CKD-T2D DALY caused by high body-mass index was positively correlated with SDI, while high temperature and lead exposure were negatively correlated. Therefore, strengthening disease screening for people aged 20-59 years and formulating early intervention measures based on the level of socioeconomic development may effectively alleviate the burden of CKD-T2D.

Podocyte Injury in Diabetic Kidney Disease in Mouse Models Involves TRPC6-mediated Calpain Activation Impairing Autophagy

SIGNIFICANCE STATEMENT

Autophagy protects podocytes from injury in diabetic kidney disease (DKD). Restoring glomerular autophagy is a promising approach to limit DKD. This study demonstrates a novel regulatory mechanism of autophagy that blocks this critical protection of the glomerular filtration barrier. We demonstrated that TRPC6 induced in podocytes in mouse models of diabetes mediates calpain activation, thereby impairing podocyte autophagy, causing injury and accelerating DKD. Furthermore, this study provides proof of principle for druggable targets for DKD because restoration of podocyte autophagy by calpain inhibitors effectively limits glomerular destruction.

BACKGROUND

Diabetic kidney disease is associated with impaired podocyte autophagy and subsequent podocyte injury. The regulation of podocyte autophagy is unique because it minimally uses the mTOR and AMPK pathways. Thus, the molecular mechanisms underlying the impaired autophagy in podocytes in diabetic kidney disease remain largely elusive.

METHODS

This study investigated how the calcium channel TRPC6 and the cysteine protease calpains deleteriously affect podocyte autophagy in diabetic kidney disease in mice. We demonstrated that TRPC6 knockdown in podocytes increased the autophagic flux because of decreased cysteine protease calpain activity. Diabetic kidney disease was induced in vivo using streptozotocin with unilateral nephrectomy and the BTBR ob/ob mouse models.

RESULTS

Diabetes increased TRPC6 expression in podocytes in vivo with decreased podocyte autophagic flux. Transgenic overexpression of the endogenous calpain inhibitor calpastatin, as well as pharmacologic inhibition of calpain activity, normalized podocyte autophagic flux, reduced nephrin loss, and prevented the development of albuminuria in diabetic mice. In kidney biopsies from patients with diabetes, we further confirmed that TRPC6 overexpression in podocytes correlates with decreased calpastatin expression, autophagy blockade, and podocyte injury.

CONCLUSIONS

Overall, we discovered a new mechanism that connects TRPC6 and calpain activity to impaired podocyte autophagy, increased podocyte injury, and development of proteinuria in the context of diabetic kidney disease. Therefore, targeting TRPC6 and/or calpain to restore podocyte autophagy might be a promising therapeutic strategy for diabetic kidney disease.

Nanopore Sequencing of RAGE Gene Polymorphisms and Their Association with Type 2 Diabetes

The receptor for advanced glycation end products (RAGE) is a transmembrane protein that interacts with its ligands, advanced glycation end products (AGEs). AGEs are elevated in diabetes and diabetic complications, leading to increased oxidative stress and activation of pro-inflammatory pathways facilitated by AGE-RAGE signaling. Polymorphisms in the RAGE gene can potentially affect AGE-RAGE interaction and its downstream signaling, which plays a crucial role in the progression of diabetes and its complications. In this study, we used nanopore sequencing for genotyping of RAGE polymorphism and identified a maximum number of 33 polymorphisms, including two previously unreported novel mutations in a cohort of healthy, type 2 diabetics without nephropathy and type 2 diabetics with nephropathy in order to identify associations. Two novel RAGE polymorphisms in the intron 8 and 3'UTR region at genomic locations 32181834 and 32181132, respectively, were detected with a low frequency. For four previously reported polymorphisms, cross-validation by PCR-RFLP showed 99.75% concordance with nanopore sequencing. Analysis of genotype distribution and allele frequencies revealed that five single nucleotide polymorphisms, i.e., rs1800625, rs3131300, rs3134940, rs2070600, and rs9391855, were associated with an increased risk for type 2 diabetes.

Analysis of reactive aldehydes in urine and plasma of type-2 diabetes mellitus patients through liquid chromatography-mass spectrometry: Reactive aldehydes as potential markers of diabetic nephropathy

Introduction

Diabetes is a major public health issue that is approaching epidemic proportions globally. Diabetes mortality is increasing in all ethnic groups, irrespective of socio-economic class. Obesity is often seen as the main contributor to an increasing prevalence of diabetes. Oxidative stress has been shown to trigger obesity by stimulating the deposition of white adipose tissue. In this study, we measured reactive aldehydes by liquid chromatography-mass spectrometry (LC-MS), in the urine and plasma of type-2 diabetic mellitus (T2DM) patients, as potential surrogates of oxidative stress. Our hypothesis was that reactive aldehydes play a significant role in the pathophysiology of diabetes, and these reactive species, may present potential drug targets for patient treatment.

Materials and methods

Study participants [N = 86; control n = 26; T2DM n = 32, and diabetic nephropathy (DN) n = 28] were recruited between 2019 and 2020. Urine and blood samples were collected from all participants, including a detailed clinical history, to include patient behaviours, medications, and co-morbidities. Reactive aldehyde concentrations in urine and plasma were measured using pre-column derivatisation and LC-MS, for control, T2DM and DN patients.

Results

Reactive aldehydes were measured in the urine and plasma of control subjects and patients with T2DM and DN. In all cases, the reactive aldehydes under investigation; 4-HNE, 4-ONE, 4-HHE, pentanal, methylglyoxal, and glyoxal, were significantly elevated in the urine and serum of the patients with T2DM and DN, compared to controls (p < 0.001) (Kruskal-Wallis). Urine and serum reactive aldehydes were significantly correlated (≥0.7) (p < 0.001) (Spearman rho). The concentrations of the reactive aldehydes were significantly higher in plasma samples, when compared to urine, suggesting that plasma is the optimal matrix for screening T2DM and DN patients for oxidative stress.

Conclusion

Reactive aldehydes are elevated in the urine and plasma of T2DM and DN patients. Reactive aldehydes have been implicated in the pathobiology of T2DM. Therefore, if reactive aldehydes are surrogates of oxidative stress, these reactive aldehyde species could be therapeutic targets for potential drug development.

MD Simulation Studies for Selective Phytochemicals as Potential Inhibitors against Major Biological Targets of Diabetic Nephropathy

Diabetes is emerging as an epidemic and is becoming a public health concern worldwide. Diabetic nephropathy is one of the serious complications of diabetes, and about 40% of individuals with diabetes develop diabetic nephropathy. The consistent feature of diabetes and its associated nephropathy is hyperglycemia, and in some cases, hyperamylinemia. Currently, the treatment includes the use of medication for blood pressure control, sugar control, and cholesterol control, and in the later stage requires dialysis and kidney transplantation, making the management of this complication very difficult. Bioactive compounds, herbal medicines, and extracts are extensively used in the treatment and prevention of several diseases, and some are reported to be efficacious in diabetes too. Therefore, in this study, we tried to identify the therapeutic potential of phytochemicals used in in silico docking and molecular dynamic simulation studies using a library of 5284 phytochemicals against the two potential targets of type 2 diabetes-associated nephropathy. We identified two phytochemicals (i.e., gentisic acid and michelalbine) that target human amylin peptide and dipeptidyl peptidase-4, respectively, with good binding affinity. These phytochemicals can be further evaluated using in vitro and in vivo studies for their anti-hyperglycemia and anti-hyperamylinemia effects.

Peripheral Blood circRNA Microarray Profiling Identities hsa_circ_0001831 and hsa_circ_0000867 as Two Novel circRNA Biomarkers for Early Type 2 Diabetic Nephropathy

PURPOSE

Type 2 diabetes mellitus (T2DM) increases the incidence of diabetic nephropathy (DN) and eventually progresses to end-stage renal disease. Circular RNAs (circRNAs) are a class of non-coding RNAs that are promising as diagnostic biomarkers and therapeutic targets for human diseases. The aim of this study was to analyze the differential expression of circRNAs (DECs) in peripheral blood from patients with early type 2 diabetic nephropathy (ET2DN), T2DM and controls, which will facilitate to discover some new biomarkers for ET2DN.

PATIENTS AND METHODS

Twenty ET2DN patients, 20 T2DM patients, and 20 normal controls were included in this study. Blood samples from 3 random subjects of age- and sex-matched patients in each group, respectively, were used to detect circRNA expression profiles by circRNA microarray, and the circRNA expression of remaining subjects was validated by real-time quantitative polymerase chain reaction (qRT-PCR). Further functional assessment was performed by bioinformatic tools.

RESULTS

There were 586 DECs in ET2DN vs T2DM group (249 circRNAs were upregulated and 337 circRNAs were downregulated); 176 circRNAs were upregulated and 101 circRNAs were downregulated in T2DM vs control group; 57 circRNAs were upregulated and 5 circRNAs were downregulated in ET2DN vs control group. The functional and pathway enrichment of DECs were analyzed by GO and KEGG. qRT-PCR results revealed that hsa_circ_0001831 and hsa_circ_0000867 were significantly upregulated in ET2DN group compared to both of T2DM and control group. The ROC curve demonstrated that hsa_circ_0001831 and hsa_circ_0000867 have high sensitivity and specificity associated with ET2DN.

CONCLUSION

Our study showed the expression profiles of circRNAs in ET2DN patients and demonstrated that hsa_circ_0001831 and hsa_circ_0000867 can be used as novel diagnostic biomarkers for ET2DN.

YAP1 promotes high glucose-induced inflammation and extracellular matrix deposition in glomerular mesangial cells by modulating NF-κB/JMJD3 pathway

Diabetic nephropathy (DN) is one of the most serious microvascular complications of late-stage diabetes. Glomerular mesangial cell (GMC) proliferation and excessive extracellular matrix (ECM) deposition are the main pathological characteristics associated with the occurrence and development of DN. Yes-associated protein 1 (YAP1) can bind to several transcription factors and is associated with the development of various diseases. However, the effects of YAP1 on DN remain unclear. The aim of the present study was to explore the regulatory effect and potential mechanism of YAP1 in glucose-induced inflammation and ECM deposition in high-glucose-treated GMCs. In the present study, HBZY-1 cell models treated with high glucose were constructed, and the effects of YAP1 on the proliferation, inflammation, ECM deposition and fibrosis of HBZY-1 cells were detected. The results showed that YAP1 was highly expressed in HBZY-1 cells treated with high glucose and that YAP1 silencing decreased cell viability, the levels of inflammatory cytokines, ECM deposition and the degree of fibrosis in cells. Further experiments revealed that NF-κB/Jumonji domain-containing protein D3 (JMJD3) signaling pathway inhibitors alleviated the promoting effect of YAP1 overexpression on inflammatory response and ECM deposition in HBZY-1 cells treated with high glucose. In conclusion, it was demonstrated that YAP1 can promote high glucose-induced inflammation and ECM deposition by activating the NF-κB/JMJD3 signaling pathway in GMCs.

Restoring glucose uptake rescues neutrophil dysfunction and protects against systemic fungal infection in mouse models of kidney disease

Disseminated candidiasis caused by the fungus Candida albicans is a major clinical problem in individuals with kidney disease and accompanying uremia; disseminated candidiasis fatality is twice as common in patients with uremia as those with normal kidney function. Many antifungal drugs are nephrotoxic, making treatment of these patients particularly challenging. The underlying basis for this impaired capacity to control infections in uremic individuals is poorly understood. Here, we show in multiple models that uremic mice exhibit an increased susceptibility to systemic fungal infection. Uremia inhibits Glut1-mediated uptake of glucose in neutrophils by causing aberrant activation of GSK3β, resulting in reduced ROS generation and hence impaired killing of C. albicans in mice. Consequently, pharmacological inhibition of GSK3β restored glucose uptake and rescued ROS production and candidacidal function of neutrophils in uremic mice. Similarly, neutrophils isolated from patients with kidney disease and undergoing hemodialysis showed similar defect in the fungal killing activity, a phenotype rescued in the presence of a GSK3β inhibitor. These findings reveal a mechanism of neutrophil dysfunction during uremia and suggest a potentially translatable therapeutic avenue for treatment of disseminated candidiasis.

Circular RNA expression profile in transgenic diabetic mouse kidneys

Background

Diabetic nephropathy is one of the most important complications in patients with diabetes. The etiology and pathogenesis of diabetic nephropathy remain unclear. Several studies have indicated that circular RNAs (circRNAs) play crucial regulatory roles in numerous human diseases and normal physiology; however, to date, no study has focused on the comprehensive expression profile of circRNAs in the kidneys of diabetic mice. Therefore, we aimed to identify differentially expressed circRNAs in diabetic mouse kidneys to explore the possible roles of dysregulated circRNAs in diabetic nephropathy development.

Results

Diabetic BKS-Lepr^em2Cd479/Nju (BKS-DB/Nju) mice and their nondiabetic wild-type littermates of C57BL/KsJ wild-type (WT) mice were used as experimental animals. Among all circRNAs identified by high-throughput RNA sequencing, four circRNAs were upregulated and ten were downregulated in diabetic mouse kidneys compared to those in nondiabetic mouse kidneys. After verification using quantitative reverse transcriptase polymerase chain reaction assays, we found that circR_1084, circR_182, circR_4, circR_50, circR_596, circR_897, and circR_203 were downregulated, whereas circR_627, circR_628, circR_735, and circR_801 were upregulated in the renal tissues of 8- and 16-week-old BKS-DB/Nju mice compared to those in WT mice.

Conclusion

We studied the circRNA expression profile in the kidneys of diabetic mice. Differentially expressed circRNAs may be useful as candidate biomarkers for diabetic nephropathy. Collectively, our results provide a novel theoretical basis for further investigation of the regulatory roles of circRNA in the etiology and pathogenesis of diabetic nephropathy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-021-00270-z.

Renal Replacement Therapy in People With and Without Diabetes in Germany, 2010-2016: An Analysis of More Than 25 Million Inhabitants

OBJECTIVE

Epidemiological studies have shown contradictory results regarding the time trend of end-stage renal disease (ESRD) in people with diabetes. This study aims to analyze the incidence of ESRD, defined as chronic renal replacement therapy (RRT), to investigate time trends among people with and without diabetes in Germany and to examine whether these patterns differ by age and sex.

RESEARCH DESIGN AND METHODS

The data were sourced from nationwide data pooled from two German branches of statutory health insurances covering ∼25 million inhabitants. We estimated age- and sex-standardized incidence rates (IRs) for chronic RRT among people with and without diabetes in 2010-2016 and the corresponding relative risks. Time trends were analyzed using Poisson regression.

RESULTS

We identified 73,638 people with a first chronic RRT (male 60.0%, diabetes 60.6%, mean age 71.3 years). The IR of chronic RRT among people with diabetes (114.1 per 100,000 person-years [95% CI 110.0-117.2]) was almost six times higher than among people without diabetes (19.6 [19.4-19.8]). A consistent decline in IR was observed among people with diabetes (3% annual reduction, P < 0.0001) for both sexes and all age classes. In contrast, no consistent change of IR was identified in people without diabetes. Only among women aged <40 years (P = 0.0003) and people aged ≥80 years (P < 0.0001) did this IR decrease significantly.

CONCLUSIONS

Incidence of chronic RRT remained significantly higher among people with diabetes. The IR decreased significantly in people with diabetes independent of age and sex. Time trends were inconsistent in people without diabetes.

Associations of serum uric acid level with diabetic retinopathy and albuminuria in patients with type 2 diabetes mellitus

Objectives

To analyze the associations of serum uric acid (SUA) level with diabetic microvascular complications, including diabetic retinopathy (DR) and diabetic nephropathy (DN), in patients with type 2 diabetes mellitus (DM).

Methods

Three hundred eighty-nine inpatients with type 2 DM were included in this retrospective analysis. Nonmydriatic fundus cameras were used to identify DR. Urinary albumin creatinine ratio was used to identify DN. Patients were divided into four groups according to SUA quartiles.

Results

The prevalences of DR and albuminuria increased with increasing SUA level. Multivariate logistic regression analysis showed that, following adjustment for other risk factors, higher levels of SUA (Q3 and Q4) were associated with greater risk for DR, compared with the lower level (Q1) (odds ratio [OR]: 3.056, 95% confidence interval [CI]: 1.506–6.198; OR: 3.417, 95% CI: 1.635–7.139, respectively). Moreover, higher levels of SUA (Q2, Q3, and Q4) were associated with greater risk for albuminuria (OR: 2.418, 95% CI: 1.059–5.522; OR: 7.233, 95% CI: 3.145–16.635; and OR: 8.911, 95% CI: 3.755–21.147, respectively).

Conclusions

SUA level was independently associated with DR and albuminuria in patients with type 2 DM. Elevated SUA level might be predictive for the occurrence of DR and DN.

Identification of Novel Biomarker for Early Detection of Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the most common complications of diabetes mellitus. After development of DN, patients will progress to end-stage renal disease, which is associated with high morbidity and mortality. Here, we developed early-stage diagnostic biomarkers to detect DN as a strategy for DN intervention. For the DN model, Zucker diabetic fatty rats were used for DN phenotyping. The results revealed that DN rats showed significantly increased blood glucose, blood urea nitrogen (BUN), and serum creatinine levels, accompanied by severe kidney injury, fibrosis and microstructural changes. In addition, DN rats showed significantly increased urinary excretion of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL). Transcriptome analysis revealed that new DN biomarkers, such as complementary component 4b (C4b), complementary factor D (CFD), C-X-C motif chemokine receptor 6 (CXCR6), and leukemia inhibitory factor (LIF) were identified. Furthermore, they were found in the urine of patients with DN. Since these biomarkers were detected in the urine and kidney of DN rats and urine of diabetic patients, the selected markers could be used as early diagnosis biomarkers for chronic diabetic nephropathy.

Protective mechanism of apigenin in diabetic nephropathy is related to its regulation of miR-423-5P-USF2 axis

Apigenin (APG), a natural flavonoid with anti-inflammatory and anti-fibrosis properties, has been shown to play a protective role in diabetic nephropathy (DN), but their molecular protection mechanism for miRNA has not been elucidated in detail. This study was designed to focus on exploring its protective role in DN and whether miR-423-5p-upstream stimulating factor 2 (USF2) axis was involved in its protective mechanism. The in vivo model of rat was induced by streptozotocin (STZ) and the in vitro model of renal tubular epithelial cell (RTEC) was induced by high glucose (HG). Our in vivo study revealed that APG had different protective effects on inflammation, renal fibrosis and epithelial mesenchymal transition (EMT) in DN rats, which is mainly reflected in that the inflammatory factors (IL-6, IFN-γ, TNF-α) were obviously down-regulated, the renal fibrosis markers (IV-C, FN, Col I) were significantly inhibited, the E-cadherin (EMT factors) was significantly up-regulated, while the vimentin and α-SMA (EMT factors) were significantly down-regulated, and the renal function indexes (serum Cr, BUN) were significantly improved. In terms of mechanism, the protective effect of APG was related to the regulation of the expression of miR-423-5p-USF2 axis, and there was a targeted relationship between miR-423-5p and USF2. Down-regulating miR-423-5p or up-regulating USF2 could significantly aggravate the disease progression of in vitro model and eliminate DN resistance under APG intervention. The above results revealed that the protective role of APG on DN was mediated by miR-423-5p-USF2 axis.

Anti-hyperglycaemic effects of dioxidovanadium complex cis-[VO2(obz)py] avert kidney dysfunction in streptozotocin-induced diabetic male Sprague-Dawley rats

Despite the success of antidiabetic drugs in alleviation of hyperglycaemia, diabetic complications, including renal dysfunction, continue to be a burden. This raises the need to seek alternative therapies that will alleviate these complications. Accordingly, the aim of this study was to investigate the effects of dioxidovanadium(V) complex cis-[VO2(obz)py] on renal function in diabetic rats. Streptozotocin-induced diabetic rats were treated with cis-[VO2(obz)py] (40 mg·kg-1) twice every third day for five weeks. Diabetic untreated and insulin-treated rats served as the diabetic control and positive control, respectively. Blood glucose concentrations, water intake, urinary output, and mean arterial pressure (MAP) were monitored weekly for five weeks. Rats were then euthanized, and blood and kidney tissues were collected for biochemical analysis. Significant decreases in blood glucose concentrations, MAP, glomerular filtration rate (GFR), and SGLT2 expression, as well as plasma angiotensin and aldosterone concentrations, were observed in the treated groups compared with the diabetic control. The complex also increased urinary glucose concentrations, antioxidant enzymes GPx and SOD concentrations, and decreased MDA concentrations and kidney injury molecule (KIM-1) concentrations. These findings suggest that the anti-hyperglycaemic effects of this vanadium complex may ameliorate kidney dysfunction in diabetes.

Changes of serum advanced glycation end products (AGEs), matrix metalloprotein-2 (MMP-2), and urinary microalbuminuria (mALB) in diabetic nephropathy and their predictive value for heart failure

Background

Diabetic nephropathy is a common complication in diabetic patients, with a high rate of disability and mortality. This study aims to explore the changes in serum advanced glycation end products (AGEs), matrix metalloprotein-2 (MMP-2), and urinary microalbuminuria (mALB) in diabetic nephropathy and their predictive value for heart failure.

Methods

The 134 patients with diabetic nephropathy treated in our hospital from January 2014 to December 2017 were enrolled and divided into two groups resulting in 64 cases in an observation group with heart failure, and 70 cases without heart failure in a control group. In addition, 80 patients with simple diabetes who were treated during the same period were selected as the simple diabetes group. Levels of AGEs, MMP-2, and mALB between the groups were compared, risk factors affecting diabetic nephropathy patients with heart failure were analyzed, and an ROC curve was drawn to evaluate the predictive value of AGEs, MMP-2, and mALB for heart failure

Results

The levels of AGEs and mALB in the diabetic nephropathy group were significantly higher than those in the simple diabetes group, and the levels of MMP-2 were significantly lower than those in the simple diabetes group (P<0.05). The levels of AGEs and mALB in the observation group were significantly higher than those in the control group, and the levels of MMP-2 were significantly lower than that in the control group (P<0.05). Smoking history hypertension history, blood creatinine (abnormal increase), blood uric acid (abnormal increase), AGEs (abnormal increase), MMP-2 (abnormal decrease), and mALB (abnormal increase) were independent risk factors affecting diabetic nephropathy patients with heart failure. The area under the ROC curve of AGEs, MMP-2, mALB, and their combined detection were: 0.821, 0.909, 0.897, and 0.991, respectively, showing the area under the curve of combined detection to be the largest.

Conclusions

AGEs, MMP-2, and mALB have high predictive value for heart failure in patients with diabetic nephropathy. Their sensitivity and specificity are high, indicating they may hold considerable clinical value.

Kidney-targeted baicalin-lysozyme conjugate ameliorates renal fibrosis in rats with diabetic nephropathy induced by streptozotocin

BACKGROUND

Diabetic nephropathy (DN) is one of the most common and serious complications of diabetes, and is the most important cause of death for diabetic patients. Baicalin (BAI) has anti-oxidative, anti-inflammatory and anti-apoptotic activities, which play a role in attenuating insulin resistance and protecting the kidney. Moreover, cell-specific targeting of renal tubular cells is an approach to enhance drug accumulation in the kidney.

METHODS

Forty-five Sprague-Dawley rats were divided into four groups. A diabetes model was created using streptozotocin (STZ) intraperitoneally injection. The four groups included: Control group (n = 10), DN (n = 15), BAI treatment (BAI; n = 10) and BAI-LZM treatment (BAI-LZM; n = 10) groups. In the current study, the renoprotection and anti-fibrotic effects of BAI-lysozyme (LZM) conjugate were further investigated in rats with DN induced by STZ compared with BAI treatment alone.

RESULTS

The results suggest that BAI-LZM better ameliorates renal impairment, metabolic disorder and renal fibrosis than BAI alone in rats with DN, and the potential regulatory mechanism likely involves inhibiting inflammation via the nuclear factor-κB signaling pathway, inhibiting extracellular matrix accumulation via the transforming growth factor-β/Smad3 pathway and regulating cell proliferation via the insulin-like growth factor (IGF)-1/IGF-1 receptor/p38 Mitogen-activated protein kinase (MAPK) pathway. BAI and the kidney-targeted BAI-LZM can utilize the body's cytoprotective pathways to reactivate autophagy (as indicated by the autophagy markers mechanistic target of rapamycin and sirtuin 1 to ameliorate DN outcomes.

CONCLUSIONS

Our data support the traditional use of S. baicalensis as an important anti-DN traditional chinese medicine (TCM), and BAI, above all BAI-LZM, is a promising source for the identification of molecules with anti-DN effects.

Incidence and relative risk of renal replacement therapy in people with and without diabetes between 2002 and 2016 in a German region

AIMS/HYPOTHESIS

Data on trends of end-stage renal disease among people with diabetes are lacking. We analysed the incidence of end-stage renal disease, defined as renal replacement therapy, among people with and without diabetes, and the corresponding relative risk. Moreover, we investigated time trends for the period 2002-2016.

METHODS

In this retrospective population-based study we analysed data from one dialysis centre of a region in Germany covering a population of about 310,000 inhabitants. We estimated the age- and sex-standardised incidence rates for chronic renal replacement therapy among adults with and without diabetes and the corresponding relative risks. The time trend was analysed using Poisson regression models.

RESULTS

Between 2002 and 2016, 1107 people (61.2% male; mean age 71.6 years; 48.7% with diabetes) had a first renal replacement therapy. During the study period, the incidence rate in the population with diabetes varied from 93.6 (95% CI 50.4, 136.7) in 2002 to 140.5 (95% CI 80.6, 200.4) in 2016 per 100,000 person-years. In the population without diabetes the incidence rate was substantially lower and reached 17.3 (95% CI 10.9, 23.6) in 2002 and 24.6 (95% CI 17.5, 31.7) in 2009. The relative risk comparing people with and without diabetes was 3.57 (95% CI 3.09, 4.13). No significant change in the incidence rates was found during the observation period, either in the population with or in the population without diabetes, and thus the relative risk also remained constant.

CONCLUSIONS/INTERPRETATION

People with diabetes have a higher risk of needing renal replacement therapy than those without diabetes, a fact that remained constant over a time period of 15 years.

Effect of Bilastine on Diabetic Nephropathy in DBA2/J Mice

Diabetic nephropathy is an unmet therapeutic need, and the search for new therapeutic strategies is warranted. Previous data point to histamine H₁ receptor as a possible target for glomerular dysfunction associated with long term hyperglycaemia. Therefore, this study investigated the effects of the H₁ receptor antagonist bilastine on renal morphology and function in a murine model of streptozotocin-induced diabetes. Diabetes was induced in DBA2/J male mice and, from diabetes onset (glycaemia ≥200 mg/dL), mice received bilastine (1–30 mg/kg/day) by oral gavage for 14 consecutive weeks. At the end of the experimental protocol, diabetic mice showed polyuria (+195.5%), increase in Albumin-to-Creatine Ratio (ACR, +284.7%), and a significant drop in creatinine clearance (p < 0.05). Bilastine prevented ACR increase and restored creatinine clearance in a dose-dependent manner, suggesting a positive effect on glomerular filtration. The ultrastructural analysis showed a preserved junctional integrity. Preservation of the basal nephrin, P-cadherin, and synaptopodin expression could explain this effect. In conclusion, the H₁ receptor could contribute to the glomerular damage occurring in diabetic nephropathy. Bilastine preserved the glomerular junctional integrity, leading to the hypothesis of anti-H₁ antihistamines as a possible add-on therapy for diabetic nephropathy.

Evolving spectrum of diabetic nephropathy

Diabetes remains an important health issue as more patients with chronic and uncontrolled diabetes develop diabetic nephropathy (DN), which classically presents with proteinuria followed by a progressive decrease in renal function. However, an increasing proportion of DN patients have a decline in kidney function and vascular complications without proteinuria, known as non-proteinuric DN (NP-DN). Despite the increased incidence of NP-DN, few clinical or experimental studies have thoroughly investigated the pathophysiological mechanisms and targeted treatment for this form of DN. In this review, we will examine the differences between conventional DN and NP-DN and consider potential pathophysiological mechanisms, diagnostic markers, and treatment for both DN and NP-DN. The investigation of the pathophysiology of NP-DN should provide additional insight into the cardiovascular factors influencing renal function and disease and provide novel treatments for the vascular complications seen in diabetic patients.

Amelioration of diabetic nephropathy using pomegranate peel extract-stabilized gold nanoparticles: assessment of NF-κB and Nrf2 signaling system

Background

Diabetic nephropathy (DN), an end-stage renal disorder, has posed a menace to humankind globally, because of its complex nature and poorly understandable intricate mechanism. In recent times, functional foods as potential health benefits have been gaining attention of consumers and researchers alike. Rich in antioxidants, the peel and seed of pomegranate have previously demonstrated protection against oxidative-stress-related diseases, including cardiovascular disorders, diabetes, and cancer.

Purpose

This study was designed to investigate the ameliorative role of pomegranate peel extract–stabilized gold nanoparticle (PPE-AuNP) on streptozotocin (STZ)-induced DN in an experimental murine model.

Methods

Following the reduction methods, AuNP was prepared using the pomegranate peel ellagitannins and characterized by particle size, physical appearance, and morphological architecture. Modulatory potential of PPE-AuNP was examined through the plethora of biochemical and high throughput techniques, flow cytometry, immunoblotting, and immunofluorescence.

Results

The animals treated with PPE-AuNP markedly reduced the fasting blood glucose, renal toxicity indices, and serum TC and TG in a hyperglycemic condition. As evident from an increased level of plasma insulin level, PPE-AuNP normalized the STZ-induced pancreatic β-cell dysfunction. The STZ-mediated suppression of endogenous antioxidant response was restored by the PPE-AuNP treatment, which reduced the generation of LPO as well as iROS. Furthermore, the hyperglycemia-mediated augmentation of protein glycation, followed by the NOX4/p-47^phox activation, diminished with the application of PPE-AuNP. The histological and immunohistochemical findings showed the protective efficacy of PPE-AuNP in reducing STZ-induced glomerular sclerosis and renal fibrosis. In addition, it reduced proinflammatory burden through the modulation of the MAPK/NF-κB/STAT3/cytokine axis. Simultaneously, PI3K/AKT-guided Nrf2 activation was evident upon the PPE-AuNP application, which enhanced the antioxidant response and maintained hyperglycemic homeostasis.

Conclusion

The findings indicate that the use of PPE-AuNPs might act as an economic therapeutic remedy for alleviating DN.

Calycosin Ameliorates Diabetes-Induced Renal Inflammation via the NF-κB Pathway In Vitro and In Vivo

BACKGROUND Diabetic nephropathy (DN), which is one of the primary causes of end-stage renal disease (ESRD), is increasingly diagnosed in patients due to the continuous increase in the prevalence of diabetic mellitus (DM). Astragali Radix, a traditional Chinese herb, is widely administrated to ameliorate the symptoms of diabetes and diabetic nephropathy, but its mechanism is still not yet fully defined. Calycosin (C₁₆H₁₂O₅) is the major active component of Astragali Radix. In this study, we analyzed the role of calycosin in diabetic nephropathy and explored its underlying mechanism. MATERIAL AND METHODS Cell activation, inflammatory cytokines expression and secretion, and protein levels were analyzed in cultured mouse tubular epithelial cells (mTEC). db/db mice were intraperitoneally injected with 10 mg/(kg·d) calycosin or control saline for 4 weeks, followed by analysis of structure injury, inflammation, and NF-κB signaling activity. RESULTS Our results indicated that TNF-α and IL-1β were significantly induced by advanced glycation end-products (AGEs), but calycosin remarkably reduced the expression of TNF-α and IL-1β in the cultured mouse tubular epithelial cells (mTEC). Calycosin effectively alleviated kidney injury in diabetic kidneys of db/db mice during the progression of diabetic renal injury, indicated by the reduction of histological injury and immunohistochemical of inflammatory cytokines. Mechanistically, we identified calycosin inhibited diabetes-induced inflammation in kidneys by suppressing the phosphorylation of IKBa and NF-κB p65 in vitro and in vivo. CONCLUSIONS Calycosin significantly ameliorated diabetes-induced renal inflammation in diabetic renal injury by inhibition of the NF-κB-dependent signaling pathway in vivo and in vitro.

Relationship between Serum Asymmetric Dimethylarginine Level and Microvascular Complications in Diabetes Mellitus: A Meta-Analysis

Objective

The purpose of the meta-analysis was to evaluate the relationship between serum asymmetric dimethylarginine (ADMA) level and microvascular complications in diabetes mellitus (DM) including diabetic retinopathy (DR), diabetic neuropathy (DN), and diabetic nephropathy.

Methods

Studies were comprehensively identified by searching Web of Science, Embase, and PubMed databases up to August 30, 2018. The meta-analysis was carried out to compare the difference of serum ADMA concentrations of DR, DN, and diabetic nephropathy patients with healthy controls. The Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality were applied to assess the methodological quality. Chi-squared Q test and I² statistics were applied to evaluate statistical heterogeneity. Subgroup analyses were conducted and publication bias was assessed by Egger's test.

Result

Ten studies were finally entered in the meta-analysis. Statistically significant heterogeneity was observed across these studies (I ² = 77.0%, p < 0.001). Compared with DM without microvascular complications, circulating level of ADMA was significantly higher in DM with microvascular complications (all p < 0.05). Sensitivity analysis suggested that the results of this meta-analysis were shown to be stable. There was no significant publication bias (P=0.823).

Conclusion

Elevated ADMA levels correlate with diabetic microangiopathies such as DR and diabetic nephropathy. ADMA may play an important role in the pathobiology of microvascular complications of diabetes.

Urinary peptidomics analysis reveals proteases involved in diabetic nephropathy

Mechanisms underlying the onset and progression of nephropathy in diabetic patients are not fully elucidated. Deregulation of proteolytic systems is a known path leading to disease manifestation, therefore we hypothesized that proteases aberrantly expressed in diabetic nephropathy (DN) may be involved in the generation of DN-associated peptides in urine. We compared urinary peptide profiles of DN patients (macroalbuminuric, n = 121) to diabetic patients with no evidence of DN (normoalbuminuric, n = 118). 302 sequenced, differentially expressed peptides (adjusted p-value < 0.05) were analysed with the Proteasix tool predicting proteases potentially involved in their generation. Activity change was estimated based on the change in abundance of the investigated peptides. Predictions were correlated with transcriptomics (Nephroseq) and relevant protein expression data from the literature. This analysis yielded seventeen proteases, including multiple forms of MMPs, cathepsin D and K, kallikrein 4 and proprotein convertases. The activity of MMP-2 and MMP-9, predicted to be decreased in DN, was investigated using zymography in a DN mouse model confirming the predictions. Collectively, this proof-of-concept study links urine peptidomics to molecular changes at the tissue level, building hypotheses for further investigation in DN and providing a workflow with potential applications to other diseases.

The large spectrum of renal disease in diabetic patients

The prevalence of diabetic nephropathy (DN) among diabetic patients seems to be overestimated. Recent studies with renal biopsies show that the incidence of non-diabetic nephropathy (NDN) among diabetic patients is higher than expected. Renal impairment of diabetic patients is frequently attributed to DN without meeting the KDOQI criteria or performing renal biopsy to exclude NDN. In this editorial, we update the spectrum of renal disease in diabetic patients and the impact on diagnosis, prognosis and therapy.