Insights into predicting diabetic nephropathy using urinary biomarkers

Unveiling diabetic nephropathy: a novel diagnostic model through single-cell sequencing and co-expression analysis

BACKGROUND

Diabetic nephropathy (DN) is a severe complication of diabetes that affects the kidneys. Disulfidptosis, a newly defined type of programmed cell death, has emerged as a potential area of interest, yet its significance in DN remains unexplored.

METHODS

This study utilized single-cell sequencing data GSE131882 from GEO database combined with bulk transcriptome sequencing data GSE30122, GSE30528 and GSE30529 to investigate disulfidptosis in DN. Single-cell sequencing analysis was performed on samples from DN patients and healthy controls, focusing on cell heterogeneity and communication. Weighted gene co-expression network analysis (WGCNA) and gene set enrichment analysis (GSEA) were employed to identify disulfidptosis-related gene sets and pathways. A diagnostic model was constructed using machine learning techniques based on identified genes, and immunocorrelation analysis was conducted to explore the relationship between key genes and immune cells. PCR validation was performed on blood samples from DN patients and healthy controls.

RESULTS

The study revealed significant disulfidptosis heterogeneity and cell communication differences in DN. Specific targets related to disulfidptosis were identified, providing insights into the pathogenesis of DN. The diagnostic model demonstrated high accuracy in distinguishing DN from healthy samples across multiple datasets. Immunocorrelation analysis highlighted the complex interactions between immune cells and key disulfidptosis-related genes. PCR validation supported the differential expression of model genes VEGFA, MAGI2, THSD7A and ANKRD28 in DN.

CONCLUSION

This research advances our understanding of DN by highlighting the role of disulfidptosis and identifying potential biomarkers for early detection and personalized treatment.

Application of Proteomics and Machine Learning Methods to Study the Pathogenesis of Diabetic Nephropathy and Screen Urinary Biomarkers

Diabetic nephropathy (DN) has become the main cause of end-stage renal disease worldwide, causing significant health problems. Early diagnosis of the disease is quite inadequate. To screen urine biomarkers of DN and explore its potential mechanism, this study collected urine from 87 patients with type 2 diabetes mellitus (which will be classified into normal albuminuria, microalbuminuria, and macroalbuminuria groups) and 38 healthy subjects. Twelve individuals from each group were then randomly selected as the screening cohort for proteomics analysis and the rest as the validation cohort. The results showed that humoral immune response, complement activation, complement and coagulation cascades, renin-angiotensin system, and cell adhesion molecules were closely related to the progression of DN. Five overlapping proteins (KLK1, CSPG4, PLAU, SERPINA3, and ALB) were identified as potential biomarkers by machine learning methods. Among them, KLK1 and CSPG4 were positively correlated with the urinary albumin to creatinine ratio (UACR), and SERPINA3 was negatively correlated with the UACR, which were validated by enzyme-linked immunosorbent assay (ELISA). This study provides new insights into disease mechanisms and biomarkers for early diagnosis of DN.

Exosomes on the development and progression of renal fibrosis

Renal fibrosis is a prevalent pathological alteration that occurs throughout the progression of primary and secondary renal disorders towards end-stage renal disease. As a complex and irreversible pathophysiological phenomenon, it includes a sequence of intricate regulatory processes at the molecular and cellular levels. Exosomes are a distinct category of extracellular vesicles that play a crucial role in facilitating intercellular communication. Multiple pathways are regulated by exosomes produced by various cell types, including tubular epithelial cells and mesenchymal stem cells, in the context of renal fibrosis. Furthermore, research has shown that exosomes present in bodily fluids, including urine and blood, may be indicators of renal fibrosis. However, the regulatory mechanism of exosomes in renal fibrosis has not been fully elucidated. This article reviewed and analysed the various mechanisms by which exosomes regulate renal fibrosis, which may provide new ideas for further study of the pathophysiological process of renal fibrosis and targeted treatment of renal fibrosis with exosomes.

Urinary biomarkers in diabetic nephropathy

Diabetic nephropathy (DN), a significant consequence of diabetes, is associated with adverse cardiovascular and renal disease as well as mortality. Although microalbuminuria is considered the best non-invasive marker for DN, better predictive markers are needed of sufficient sensitivity and specificity to detect disease in general and in early disease specifically. Even prior to appearance of microalbuminuria, urinary biomarkers increase in diabetics and can serve as accurate nephropathy biomarkers even in normoalbuminuria. In this review, a number of novel urine biomarkers including those reflecting kidney damage caused by glomerular/podocyte damage, tubular damage, oxidative stress, inflammation, and intrarenal renin-angiotensin system activation are discussed. Our review also includes emerging biomarkers such as urinary microRNAs. These short noncoding miRNAs regulate gene expression and could be utilized to identify potential novel biomarkers in DN development and progression. .

Jiawei Shengjiangsan's Effect on Renal Injury in Diabetic Nephropathy Mice is Investigated via the PI3K/Akt/NF-κB Signaling Pathway

Purpose

This study aimed to investigate the intervention mechanism of Jiawei Shengjiangsan (JWSJS) on kidney injury in diabetic nephropathy mice.

Methods

Thirty 8-week-old db/db mice were randomly divided into five groups: model group, Perindopril group, and JWSJS low-, medium-, and high-dose groups (n=6 per group) based on body weight. Additionally, a blank control group was established consisting of 6 db/m mice aged 8 weeks. The blank and model groups received daily intragastric administration of 7g/kg/d pure water. The remaining groups were assigned to JWSJS low (3.5g/kg/d), medium (7g/kg/d), high (14g/kg/d) dosage groups, and perindopril positive control group (0.48mg/kg/d) for 12 weeks. Post-experiment, serum creatinine (SCr) and blood urea nitrogen (BUN) were analyzed using an automatic biochemical analyzer. Enzyme-linked immunosorbent assay (ELISA) measured 24-hour urinary albumin, neutrophil gelatinase-associated lipocalin (NGAL), TNF-α, IL-1β, VCAM-1, MCP-1, and HbA1c. Western blot assessed the protein expressions of p-PI3K, p-Akt, and p-NF-κB p65, while pathological kidney changes were observed.

Results

Compared to the blank group, the model group exhibited increased SCr, BUN, 24-hour urinary albumin, serum NGAL, TNF-α, IL-1β, VCAM-1, MCP-1, HbA1c, p-PI3K, and p-Akt, alongside increased p-NF-κB p65 expression, indicating significant kidney pathology. After treatment, the JWSJS group showed decreased SCr, BUN, 24-hour urinary microalbumin, NGAL, HbA1c, TNF-α, IL-1β, VCAM-1, MCP-1 levels, increased p-PI3K and p-Akt expression (P<0.05), and reduced p-NF-κB p65 content (P<0.05). Histopathological analysis revealed that JWSJS ameliorated renal tubular epithelial cell damage, glomerular capillary and basement membrane injuries, and facilitated the repair of damaged podocytes in diabetic nephropathy mice.

Conclusion

JWSJS demonstrated efficacy in reducing renal inflammation in diabetic nephropathy mice, with its mechanism likely associated with the inhibition of the PI3K/Akt/NF-κB signaling pathway.

Biomarkers and signaling pathways of diabetic nephropathy and peripheral neuropathy: possible therapeutic intervention of rutin and quercetin

Diabetic nephropathy and peripheral neuropathy are the two main complications of chronic diabetes that contribute to high morbidity and mortality. These conditions are characterized by the dysregulation of multiple molecular signaling pathways and the presence of specific biomarkers such as inflammatory cytokines, indicators of oxidative stress, and components of the renin-angiotensin system. In this review, we systematically collected and collated the relevant information from MEDLINE, EMBASE, ELSEVIER, PUBMED, GOOGLE, WEB OF SCIENCE, and SCOPUS databases. This review was conceived with primary objective of revealing the functions of these biomarkers and signaling pathways in the initiation and progression of diabetic nephropathy and peripheral neuropathy. We also highlighted the potential therapeutic effectiveness of rutin and quercetin, two plant-derived flavonoids known for their antioxidant and anti-inflammatory properties. The findings of our study demonstrated that both flavonoids can regulate important disease-promoting systems, such as inflammation, oxidative stress, and dysregulation of the renin-angiotensin system. Importantly, rutin and quercetin have shown protective benefits against nephropathy and neuropathy in diabetic animal models, suggesting them as potential therapeutic agents. These findings provide a solid foundation for further comprehensive investigations and clinical trials to evaluate the potential of rutin and quercetin in the management of diabetic nephropathy and peripheral neuropathy. This may contribute to the development of more efficient and comprehensive treatment approaches for diabetes-associated complications.

Quantitative comparison of the renal pelvic urine and bladder urine to examine modifications of the urine proteome by the lower urinary tract

PURPOSE

Urine proteome is a valuable reservoir of biomarkers for disease diagnosis and monitoring. Following formation as the plasma filtrate in the kidney, urine is progressively modified by the active reabsorption and secretion of the urinary tract. However, little is known about how the urine proteome changes as it passes along the urinary tract.

EXPERIMENTAL DESIGN

To investigate this, we compared the proteome composition of the renal pelvis urine (RPU) and individually self-voided bladder urine (BU) collected from seven unilateral urinary tract obstruction male patients by LC-MS/MS screening. To our knowledge, this is the first proteomic comparison of RPU and BU samples from the same individual.

RESULTS

Overall, RPU and BU proteomes did not exhibit proteins that were exclusively present in all samples of one urine type while in none of the other type. Nonetheless, BU had more overrepresented proteins that were observed at a higher frequency than RPU. Label-free quantitative analyses revealed BU-RPU differential proteins that are enriched in exosomes and extracellular proteins. However, the differences were not significant after corrections for multiple testing. Interestingly, we observed a significant increase of collagen peptides with hydroxyproline modifications in the BU samples, suggesting differences in protein modifications.

CONCLUSIONS AND CLINICAL RELEVANCE

Our study revealed no substantial differences at the protein level between the BU and RPU samples. Future investigations with expanded cohorts would provide more insights about the urothelial-urinary interactions.

ACSL1: A preliminary study that provides a new target for the treatment of renal fibrosis could bring new insights in diabetic kidney disease

BACKGROUND

Renal fibrosis is the main cause of the development of diabetic kidney disease (DKD). ACSL1 plays an important role in colon cancer and liver fibrosis.

METHODS

We screened ACSL1 by proteomics analysis and then verified the expression of ACSL1 in the urine of diabetic nephropathy patients by WB and ELISA. Then, a total of 12db/m and db/db mice were used to verify the association between renal fibrosis and ACSL1. Periodic acid-Schiff (PAS) staining, Masson staining, and immunostaining were performed for histological studies. The relationship between ACSL1 and renal fibrosis was studied by knocking down ACSL1 in cell experiments.

RESULTS

The expression of ACSL1 was significantly increased in the exfoliated urine cells and urine supernatant of diabetic nephropathy patients and was closely related to renal function. In addition, the expression of ACSL1 was significantly increased in the renal tissues of db/db mice with fibrosis. Knocking down ACSL1 in HK-2 cells was shown to reverse renal fibrosis induced by high glucose.

CONCLUSIONS

We found a potential therapeutic target for preventing or ameliorating the progression of DKD fibrosis. Reducing ACSL1 expression may be a new strategy for the treatment of renal fibrosis caused by DKD, which provides an experimental theoretical basis for new drug research.

Progression of diabetic nephropathy and vitamin D serum levels: A pooled analysis of 7722 patients

BACKGROUND AND AIM

Low serum Vitamin D levels have been associated with diabetic nephropathy (DN). Our study aimed to analyse the serum levels of vitamin D in patients suffering from DN and the subsequent changes in serum vitamin D levels as the disease progresses.

METHODS

PubMed, Embase, SCOPUS and Web of Science were searched using keywords such as '25 hydroxyvitamin D' and 'diabetic nephropathy'. We included observational studies that reported the association between the serum 25 hydroxy vitamin D levels and diabetic nephropathy without restriction to age, gender, and location. R Version 4.1.2 was used to perform the meta-analysis. The continuous outcomes were represented as mean difference (MD) and standard deviation (SD) and dichotomous outcomes as risk ratios (RR) with their 95% confidence interval (CI).

RESULTS

Twenty-three studies were included in our analysis with 7722 patients. Our analysis revealed that vitamin D was significantly lower in diabetic patients with nephropathy than those without nephropathy (MD: -4.32, 95% CI: 7.91-0.74, p-value = .0228). On comparing diabetic patients suffering from normoalbuminuria, microalbuminuria, or macroalbuminuria, we found a significant difference in serum vitamin D levels across different groups. Normoalbuminuria versus microalbuminuria showed a MD of -1.69 (95% CI: -2.28 to -1.10, p-value = .0002), while microalbuminuria versus macroalbuminuria showed a MD of (3.75, 95% CI: 1.43-6.06, p-value = .0058), proving that serum vitamin D levels keep declining as the disease progresses. Notwithstanding, we detected an insignificant association between Grade 4 and Grade 5 DN (MD: 2.29, 95% CI: -2.69-7.28, p-value = .1862).

CONCLUSION

Serum Vitamin D levels are lower among DN patients and keep declining as the disease progresses, suggesting its potential benefit as a prognostic marker. However, on reaching the macroalbuminuria stage (Grades 4 and 5), vitamin D is no longer a discriminating factor.

Protective effect of eriodictyol against hyperglycemia-induced diabetic nephropathy in rats entails antioxidant and anti-inflammatory effects mediated by activating Nrf2

The pathogenesis of diabetic nephropathy (DN) involves cellular activation of oxidative stress and inflammation. Eriodictyol is a citrus-derived flavonoid with multiple pharmacological and protective effects in various conditions. The protective role of Eriodictyol against diabetes and diabetic nephropathy is less investigated. The current research aimed to explore the role of eriodictyol in protecting against DN prompted by streptozotocin in male rats and investigate some possible mechanisms of action. Diabetes was brought about in rats by an i.p injection of a lone dose (65 mg/kg). Five groups of rats were included (n = 8 each) as control (non-diabetic), eriodictyol (20 mg/kg, orally), STZ-diabetic, STZ + eriodictyol (20 mg/kg, orally), and STZ + eriodictyol (20 mg/kg, orally) + ML385 (30 µg/kg, i.p.). Kidney histology and the levels of some markers of kidney function, renal oxidative stress, and renal inflammation were analyzed in all groups of rats. Treatment with eriodictyol prevented the damage in the renal glomeruli and tubules and reduced renal immune cell infiltration in STZ-treated animals. It also spiked urinary creatinine excretion and reduced urine volume and urinary levels of albumin, monocyte chemoattractant protein 1 (MCP-1), urinary kidney injury molecule-1 (KIM-1), and nephrin in these diabetic rats. In addition, eriodictyol stimulated the nuclear protein accumulation of Nrf2 and boosted the expression of superoxide dismutase (SOD), glutathione (GSH), heme oxygenase-1 (HO-1), and catalase (CAT) in the diabetic rat kidneys. In concomitance, it reduced the nuclear levels of NF-κB and levels of interleukine-6 (IL-6), malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) and attenuated the reduction in renal ATP levels and the increase in the mitochondria transition pore opening (mtTPT). However, the administration of eriodictyol did not affect rats' body weights and fasting glucose and insulin levels but significantly reduced serum levels of cholesterol, triglycerides, LDL-c, and oxidized LDL-c (ox-LDL-c). In conclusion, eriodictyol prevents STZ-induced nephropathy by a hypolipidemic effect and concomitant antioxidant and anti-inflammatory effects mediated by activating Nrf2/NF-κB/antioxidant axis.

Effects of paricalcitol combined with hemodiafiltration on bone-metabolism-related indexes in patients with diabetic nephropathy and chronic renal failure

BACKGROUND

Diabetic nephropathy (DN) is frequently seen in the development of diabetes mellitus, and its pathogenic factors are complicated. Its current treatment is controversial, and there is a lack of a relevant efficacy prediction model.

AIM

To determine the effects of paricalcitol combined with hemodiafiltration on bone-metabolism-related indexes in patients with DN and chronic renal failure (CRF), and to construct an efficacy prediction model.

METHODS

We retrospectively analyzed 422 patients with DN and CRF treated in Cangzhou Central Hospital between May 2020 and May 2022. We selected 94 patients who met the inclusion and exclusion criteria. Patients were assigned to a dialysis group (n = 45) and a joint group (n = 49) in relation to therapeutic regimen. The clinical efficacy of the two groups was compared after treatment. The changes in laboratory indexes after treatment were evaluated, and the two groups were compared for the incidence of adverse reactions. The predictive value of laboratory indexes on the clinical efficacy on patients was analyzed.

RESULTS

The dialysis group showed a notably worse improvement in clinical efficacy than the joint group (P = 0.017). After treatment, the joint group showed notably lower serum levels of serum creatinine, uric acid (UA) and blood urea nitrogen (BUN) than the dialysis group (P < 0.05). After treatment, the joint group had lower serum levels of phosphorus, procollagen type I amino-terminal propeptide (PINP) and intact parathyroid hormone than the dialysis group, but a higher calcium level (P < 0.001). Both groups had a similar incidence of adverse reactions (P > 0.05). According to least absolute shrinkage and selection operator regression analysis, UA, BUN, phosphorus and PINP were related to treatment efficacy. According to further comparison, the non-improvement group had higher risk scores than the improvement group (P < 0.0001), and the area under the curve of the risk score in efficacy prediction was 0.945.

CONCLUSION

For treatment of CRF and DN, combined paricalcitol and hemodiafiltration can deliver higher clinical efficacy and improve the bone metabolism of patients, with good safety.

Hsa_circ_0005548 knockdown repairs OGD/R-induced damage in human brain microvascular endothelial cells via miR-362-3p/ETS1 axis

BACKGROUND

Ischemic stroke (IS) is a highly prevalent type of stroke with very high rates of disability and death. As the regulatory role of circular RNAs (circRNAs) in various diseases has been revealed, we constructed a stroke cell model to analyze the action mechanism of hsa_circ_0005548 in IS.

METHODS

The abundance of hsa_circ_0005548, microRNA-362-3p (miR-362-3p) and E26 transformation specific-1 (ETS-1) were measured by real-time quantitative polymerase chain reaction (RT-qPCR) or western blot. We constructed an IS cell model in vitro by oxygen-glucose deprivation/reperfusion (OGD/R) treatment and analyzed cell proliferation, apoptosis and inflammatory response through the use of Cell Counting Kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry and Enzyme-linked immunosorbent assay (ELISA), respectively. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were employed for the analysis of the relationship between miR-362-3p and hsa_circ_0005548 or ETS1.

RESULTS

The higher abundance of hsa_circ_0005548 and ETS-1 and lower level of miR-362-3p were observed in human brain microvascular endothelial immortalized (HBMEC-IM) cells under OGD/R. Hsa_circ_0005548 downregulation mitigated OGD/R-induced HBMEC-IM cell injury. Mechanistically, hsa_circ_0005548 targeted miR-362-3p. MiR-362-3p knockdown reversed the effect of hsa_circ_0005548 silencing on OGD/R-induced HBMEC-IM cell injury. ETS1 was validated as a direct target of miR-362-3p, and miR-362-3p attenuated OGD/R-induced HBMEC-IM cell injury by ETS1. Moreover, hsa_circ_0005548 modulated ETS1 via miR-362-3p.

CONCLUSION

Hsa_circ_0005548 knockdown repairs OGD/R-induced HBMEC-IM cell damage via miR-362-3p/ETS1 axis.

V-ATPase subunit C 1 and IKBIP as tandem prospective biomarkers for diabetic nephropathy

AIMS

The appearance of low-molecular-weight (LMW) protein in the urine indicates any disruption in the structural integrity of the glomerular capillary wall; therefore, the presence of LMW protein may be a potential predictive marker for DN.

METHODS

The urine proteomic profiling of T2DM patients (n = 94) and control group (n = 32) was compared by liquid chromatography-tandem mass spectrometry, and the untargeted LMW protein was identified by Progenesis Q1 For Proteomics v4.2.

RESULTS

A total of 73 LMW proteins were identified and quantified, of which, 32 proteins were found to be altered significantly (p < 0.05). Further analysis with heat maps identified two potential proteins with the highest folding alterations in urine. V-ATPase subunit C 1 abundance was significantly inversely correlated with microalbumin and significantly decreased in urine, whereas increased IKBIP was positively correlated with microalbumin. The level of those proteins was significantly different among the control, T2DM, and DN groups, implying an association with the progression of DN.

CONCLUSIONS

The present findings of our study indicate that the decreasing V-ATPase subunit C 1 together with increasing IKBIP in urine, were found to be closely associated with DN complications and signifying their value as biomarkers for predicting the risk of DN at initial diagnosis.

Preliminary Feasibility Study on Diffusion Kurtosis Imaging to Monitor the Early Functional Alterations of Kidneys in Streptozocin-Induced Diabetic Rats

RATIONALE AND OBJECTIVES

The aim of this study was to investigate the potential of diffusion kurtosis imaging (DKI) to assess the early renal functional undulation of diabetic mellitus (DM).

MATERIALS AND METHODS

Fifty-seven Sprague-Dawley (SD) rats were randomly divided into two groups and eventually 48 rats were included in this study: the normal control (CON) group and diabetic mellitus (DM) group. Weeks 0, 4, 8, and 12 after the diabetes model was successfully established, all the rats were scanned on the 3.0T MRI. The DKI derived parameters of renal parenchyma, including fractional anisotropy (FAco, FAme), mean diffusivity (MDco, MDme), and mean kurtosis (MKco, MKme) were measured. Their alteration over time was analyzed and then correlated with urine volume (UV), blood urea nitrogen (BUN), and serum creatinine (Scr) using Pearson correlation analysis. Finally, hematoxylin and eosin (H&E) staining was performed on the kidneys of the two groups.

RESULT

There was a decreasing trend in FA, MK, and MD values over time in diabetic rats. Also, the gradually worsening histological damage of kidneys was noted over time in diabetic rats. The cortical FA and MK values and medullary FA, MK and MD values of diabetic rats were significantly lower than those of controls at most time points after DM induction. In addition, negative correlations were revealed between the BUN and FAco (r = -0.43, p = 0.03) or FAme value (r = -0.49, p = 0.01). The cortical MK value was moderately correlated with UV (r = -0.46, p = 0.03) and BUN (r = -0.55, p = 0.01).

CONCLUSION

The preliminary findings suggest that DKI might be an effective and sensitive tool to assess the early changes of renal function impairment in diabetic rats. The FA values of the cortex and medulla and the MK value of the cortex are sensitive markers in detecting renal injury in diabetic rats.

Lysozyme promotes renal fibrosis through the JAK/STAT3 signal pathway in diabetic nephropathy

Introduction

Diabetic nephropathy (DN) is a leading cause of kidney failure. Lysozyme (LYZ) is an essential component of innate immunity and exhibits antibacterial properties. However, LYZ has been reported to induce nephropathy, implying a possible association between impaired renal function and lysozyme expression.

Material and methods

Bioinformatics analysis was used to predict the hub gene associated with DN, and the differential expression of the hub gene was confirmed using a mouse model. A mouse model of streptozotocin (STZ)-induced diabetic nephropathy was established to investigate the correlation between DN and LYZ expression, and the functionality of LYZ was verified through knockdown and overexpression experiments conducted in vivo. Immunohistochemistry (IHC) was utilized to assess fibrosis-related markers and cytokines, while Masson staining was performed to assess renal fibrosis. Fibroblast proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay. The role of the JAK pathway was confirmed using the JAK inhibitor AG490, and Western blot was used to investigate the underlying mechanisms.

Results

Mechanistically, 25 mM glucose promotes the expression of LYZ in fibroblastic cells, and LYZ may in turn promote the proliferation of renal interstitial fibroblasts. Western blot shows that glucose can activate STAT3 in an LYZ-dependent manner, and the JAK inhibitor AG490 can partially suppress LYZ-induced STAT3 activation. Furthermore, in vivo observations have revealed that overexpression of LYZ is associated with the senescent phenotype of renal tubular epithelial cells (RTECs).

Conclusions

Lysozyme promotes kidney fibrosis via the JAK/STAT3 signaling pathway in diabetic nephropathy, and glucose may promote fibroblast proliferation by promoting LYZ auto-secretion.

Machine-learning algorithm-based prediction of a diagnostic model based on oxidative stress-related genes involved in immune infiltration in diabetic nephropathy patients

Diabetic nephropathy (DN) is the most prevalent microvascular consequence of diabetes and has recently risen to the position of the world's second biggest cause of end-stage renal diseases. Growing studies suggest that oxidative stress (OS) responses are connected to the advancement of DN. This study aimed to developed a novel diagnostic model based on OS-related genes. The differentially expressed oxidative stress-related genes (DE-OSRGs) experiments required two human gene expression datasets, which were given by the GEO database (GSE30528 and GSE96804, respectively). The potential diagnostic genes were identified using the SVM-RFE assays and the LASSO regression model. CIBERSORT was used to determine the compositional patterns of the 22 different kinds of immune cell fraction seen in DN. These estimates were based on the combined cohorts. DN serum samples and normal samples were both subjected to RT-PCR in order to investigate the degree to which certain genes were expressed. In this study, we were able to locate 774 DE-OSRGs in DN. The three marker genes (DUSP1, PRDX6 and S100A8) were discovered via machine learning on two different machines. The high diagnostic value was validated by ROC tests, which focused on distinguishing DN samples from normal samples. The results of the CIBERSORT study suggested that DUSP1, PRDX6, and S100A8 may be associated to the alterations that occur in the immunological microenvironment of DN patients. Besides, the results of RT-PCR indicated that the expression of DUSP1, PRDX6, and S100A8 was much lower in DN serum samples compared normal serum samples. The diagnostic value of the proposed model was likewise verified in our cohort, with an area under the curve of 9.946. Overall, DUSP1, PRDX6, and S100A8 were identified to be the three diagnostic characteristic genes of DN. It's possible that combining these genes will be effective in diagnosing DN and determining the extent of immune cell infiltration.

Differential expression of coagulation pathway-related proteins in diabetic urine exosomes

BACKGROUND

Coagulation function monitoring is important for the occurrence and development of diabetes. A total of 16 related proteins are involved in coagulation, but how these proteins change in diabetic urine exosomes is unclear. To explore the expression changes of coagulation-related proteins in urine exosomes and their possible roles in the pathogenesis of diabetes, we performed proteomic analysis and finally applied them to the noninvasive monitoring of diabetes.

METHODS

Subject urine samples were collected. LC-MS/MS was used to collect the information on coagulation-related proteins in urine exosomes. ELISA, mass spectrometry and western blotting were used to further verify the differential protein expression in urine exosomes. Correlations with clinical indicators were explored, and receiver operating characteristic (ROC) curves were drawn to evaluate the value of differential proteins in diabetes monitoring.

RESULTS

Analyzing urine exosome proteomics data, eight coagulation-related proteins were found in this study. Among them, F2 was elevated in urine exosomes of diabetic patients compared with healthy controls. The results of ELISA, mass spectrometry and western blotting further verified the changes in F2. Correlation analysis showed that the expression of urine exosome F2 was correlated with clinical lipid metabolism indexes, and the concentration of F2 was strongly positively correlated with blood TG levels (P < 0.05). ROC curve analysis showed that F2 protein in urine exosomes had a good monitoring value for diabetes.

CONCLUSION

Coagulation-related proteins were expressed in urine exosomes. Among them, F2 was increased in diabetic urine exosomes and may be a potential biomarker for monitoring diabetic changes.

Intracellular Antioxidant and Anti-Inflammatory Effects and Bioactive Profiles of Coffee Cascara and Black Tea Kombucha Beverages

Kombucha is a functional beverage obtained through fermentation of sweetened Camellia sinensis infusion by a symbiotic culture of bacteria and yeasts that exerts many beneficial biological effects, mostly related to its antioxidant and anti-inflammatory effects. Alternative raw materials have been used to create new kombucha or kombucha-like products. Coffee is the most important food commodity worldwide and generates large amounts of by-products during harvest and post-harvest processing. The main coffee by-product is the dried fruit skin and pulp, popularly known as cascara. To date, no studies have evaluated the potential bioactivity of coffee cascara kombucha. In this study, we aimed to measure and compare the effects of infusions and kombuchas made with arabica coffee cascaras (n = 2) and black tea leaves (n = 1), fermented for 0, 3, 6, and 9 days on the intracellular production of Reactive Oxygen Species (ROS) and Nitric Oxide (NO) in model cells. Oxidative stress was induced in HK-2 cells with indoxyl sulfate (IS) and high glucose (G). Inflammation was induced with lipopolysaccharide (LPS) in RAW 264.7 macrophage. The contents of phenolic compounds, caffeine, and other physicochemical parameters were evaluated. To the best of our knowledge, this is the first study providing information on the bioactive profile and on the potential biological effects of coffee cascara kombucha. Fermentation caused the release of bound phenolic compounds from the infusions, especially total chlorogenic acids, with an average increase from 5.4 to 10.7 mg/100 mL (98%) and 2.6-3.4 mg/100 mL (30%) in coffee cascara and black tea kombucha, respectively, up to day 9. All evaluated beverages reduced (p < 0.0001) similarly the intracellular ROS (41% reduction, on average) and uric acid (10-55%) concentrations in HK-2 model cells, reversing the induced oxidative stress. All beverages also reduced (p < 0.0001, 81-90%) NO formation in LPS-induced macrophages, exhibiting an anti-inflammatory effect. These potential health benefits may be mostly attributed to polyphenols and caffeine, whose contents were comparable in all beverages. Coffee cascara showed similar potential to C. sinensis to produce healthy beverages and support sustainable coffee production.

Ginsenosides from Panax ginseng as Key Modulators of NF-κB Signaling Are Powerful Anti-Inflammatory and Anticancer Agents

Nuclear factor kappa B (NF-κB) signaling pathways progress inflammation and immune cell differentiation in the host immune response; however, the uncontrollable stimulation of NF-κB signaling is responsible for several inflammatory illnesses regardless of whether the conditions are acute or chronic. Innate immune cells, such as macrophages, microglia, and Kupffer cells, secrete pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1β, via the activation of NF-κB subunits, which may lead to the damage of normal cells, including neurons, cardiomyocytes, hepatocytes, and alveolar cells. This results in the occurrence of neurodegenerative disorders, cardiac infarction, or liver injury, which may eventually lead to systemic inflammation or cancer. Recently, ginsenosides from Panax ginseng, a historical herbal plant used in East Asia, have been used as possible options for curing inflammatory diseases. All of the ginsenosides tested target different steps of the NF-κB signaling pathway, ameliorating the symptoms of severe illnesses. Moreover, ginsenosides inhibit the NF-κB-mediated activation of cancer metastasis and immune resistance, significantly attenuating the expression of MMPs, Snail, Slug, TWIST1, and PD-L1. This review introduces current studies on the therapeutic efficacy of ginsenosides in alleviating NF-κB responses and emphasizes the critical role of ginsenosides in severe inflammatory diseases as well as cancers.

A Review of Medicinal Plants with Renoprotective Activity in Diabetic Nephropathy Animal Models

Diabetic nephropathy (DN), also recognized as diabetic kidney disease, is a kidney malfunction caused by diabetes mellitus. A possible contributing factor to the onset of DN is hyperglycemia. Poorly regulated hyperglycemia can damage blood vessel clusters in the kidneys, leading to kidney damage. Its treatment is difficult and expensive because its causes are extremely complex and poorly understood. Extracts from medicinal plants can be an alternative treatment for DN. The bioactive content in medicinal plants inhibits the progression of DN. This work explores the renoprotective activity and possible mechanisms of various medicinal plant extracts administered to diabetic animal models. Research articles published from 2011 to 2022 were gathered from several databases including PubMed, Scopus, ProQuest, and ScienceDirect to ensure up-to-date findings. Results showed that medicinal plant extracts ameliorated the progression of DN via the reduction in oxidative stress and suppression of inflammation, advanced glycation end-product formation, cell apoptosis, and tissue injury-related protein expression.

Bibliometric Analysis and Visualization of Research Progress in the Diabetic Nephropathy Field from 2001 to 2021

Methods

The PubMed database was searched to identify all studies related to DN that were published from 2001 to 2021, with these studies being separated into four time-based groups. The characteristics of these studies were analyzed and extracted using BICOMB. Biclustering analyses for each of these groups were then performed using gCLUTO, with these results then being analyzed and GraphPad Prism 5 being used to construct strategy diagrams. The social network analyses (SNAs) for each group of studies were conducted using NetDraw and UCINET.

Results

In total, 18,889 DN-associated studies published from 2001 to 2021 and included in the PubMed database were incorporated into the present bibliometric analysis. Biclustering analysis and strategy diagrams revealed that active areas of research interest in the DN field include studies of the drug-based treatment, diagnosis, etiology, pathology, physiopathology, and epidemiology of DN. The specific research topics associated with these individual areas, however, have evolved over time in a dynamic manner. Strategy diagrams and SNA results revealed podocyte metabolism as an emerging research hotspot in the DN research field from 2010 to 2015, while DN-related microRNAs, signal transduction, and mesangial cell metabolism have emerged as more recent research hotspots in the interval from 2016 to 2021.

Conclusion

Through analyses of PubMed-indexed studies pertaining to DN published since 2001, the results of this bibliometric analysis offer a knowledge framework and insight into active and historical research hotspots in the DN research space, enabling investigators to readily understand the dynamic evolution of this field over the past two decades. Importantly, these analyses also enable the prediction of future DN-related research hotspots, thereby potentially guiding more focused and impactful research efforts.

TRAIL and EGFR Pathways Targeting microRNAs are Predominantly Regulated in Human Diabetic Nephropathy

BACKGROUND

Unbiased microRNA profiling of renal tissue and urinary extracellular vesicles (uEVs) from diabetic nephropathy (DN) subjects may unravel novel targets with diagnostic and therapeutic potential. Here we used the miRNA profile of uEVs and renal biopsies from DN subjects available on the GEO database.

METHODS

The miR expression profiles of kidney tissue (GSE51674) and urinary exosomes (GSE48318) from DN and control subjects were obtained by GEO2R tools from Gene Expression Omnibus (GEO) databases. Differentially expressed miRNAs in DN samples, relative to controls, were identified using a bioinformatic pipeline. Targets of miRs commonly regulated in both sample types were predicted by miRWalk, followed by functional gene enrichment analysis. Gene targets were identified by MiRTarBase, TargetScan and MiRDB.

RESULTS

Eight miRs, including let-7c, miR-10a, miR-10b and miR-181c, were significantly regulated in kidney tissue and uEVs in DN subjects versus controls. The top 10 significant pathways targeted by these miRs included TRAIL, EGFR, Proteoglycan syndecan, VEGF and Integrin Pathway. Gene target analysis by miRwalk upon validation using ShinyGO 70 targets with significant miRNA-mRNA interaction.

CONCLUSION

In silico analysis showed that miRs targeting TRAIL and EGFR signaling are predominately regulated in uEVs and renal tissue of DN subjects. After wet-lab validation, the identified miRstarget pairs may be explored for their diagnostic and/or therapeutic potential in diabetic nephropathy.

Molecular Pathways of Diabetic Kidney Disease Inferred from Proteomics

Diabetic kidney disease (DKD) affects an estimated 20-40% of type 2 diabetes patients and is among the most prevalent microvascular complications in this patient population, contributing to high morbidity and mortality rates. Currently, changes in albuminuria status are thought to be a primary indicator of the onset or progression of DKD, yet progressive nephropathy and renal impairment can occur in certain diabetic individuals who exhibit normal urinary albumin levels, emphasizing the lack of sensitivity and specificity associated with the use of albuminuria as a biomarker for detecting diabetic kidney disease and predicting DKD risk. According to the study, a non-invasive method for early detection or prediction of DKD may involve combining proteomic analytical techniques such second generation sequencing, mass spectrometry, two-dimensional gel electrophoresis, and other advanced system biology algorithms. Another category of proteins of relevance may now be provided by renal tissue biomarkers. The establishment of reliable proteomic biomarkers of DKD represents a novel approach to improving the diagnosis, prognostic evaluation, and treatment of affected patients. In the present review, a series of protein biomarkers that have been characterized to date are discussed, offering a theoretical foundation for future efforts to aid patients suffering from this debilitating microvascular complication.

Oxidative Stress and NRF2/KEAP1/ARE Pathway in Diabetic Kidney Disease (DKD): New Perspectives

Diabetes mellitus (DM) is one of the most debilitating chronic diseases worldwide, with increased prevalence and incidence. In addition to its macrovascular damage, through its microvascular complications, such as Diabetic Kidney Disease (DKD), DM further compounds the quality of life of these patients. Considering DKD is the main cause of end-stage renal disease (ESRD) in developed countries, extensive research is currently investigating the matrix of DKD pathophysiology. Hyperglycemia, inflammation and oxidative stress (OS) are the main mechanisms behind this disease. By generating pro-inflammatory factors (e.g., IL-1,6,18, TNF-α, TGF-β, NF-κB, MCP-1, VCAM-1, ICAM-1) and the activation of diverse pathways (e.g., PKC, ROCK, AGE/RAGE, JAK-STAT), they promote a pro-oxidant state with impairment of the antioxidant system (NRF2/KEAP1/ARE pathway) and, finally, alterations in the renal filtration unit. Hitherto, a wide spectrum of pre-clinical and clinical studies shows the beneficial use of NRF2-inducing strategies, such as NRF2 activators (e.g., Bardoxolone methyl, Curcumin, Sulforaphane and their analogues), and other natural compounds with antioxidant properties in DKD treatment. However, limitations regarding the lack of larger clinical trials, solubility or delivery hamper their implementation for clinical use. Therefore, in this review, we will discuss DKD mechanisms, especially oxidative stress (OS) and NRF2/KEAP1/ARE involvement, while highlighting the potential of therapeutic approaches that target DKD via OS.

Pharmacological Activities of Safflower Yellow and Its Clinical Applications

Background. Safflower is an annual herb used in traditional Chinese herbal medicine. It consists of the dried flowers of the Compositae plant safflower. It is found in the central inland areas of Asia and is widely cultivated throughout the country. Its resistance to cold weather and droughts and its tolerance and adaptability to salts and alkalis are strong. Safflower has the effect of activating blood circulation, dispersing blood stasis, and relieving pain. A natural pigment named safflower yellow (SY) can be extracted from safflower petals. Chemically, SY is a water-soluble flavonoid and the main active ingredient of safflower. The main chemical constituents, pharmacological properties, and clinical applications of SY are reviewed in this paper, thereby providing a reference for the use of safflower in preventing and treating human diseases. Methods. The literature published in recent years was reviewed, and the main chemical components of SY were identified based on chemical formula and structure. The pharmacological properties of hydroxysafflor yellow A (HSYA), SYA, SYB, and anhydrosafflor yellow B (AHSYB) were reviewed. Results. The main chemical constituents of SY included HSYA, SYA, SYB, and AHSYB. These ingredients have a wide range of pharmacological activities. SY has protective effects on the heart, kidneys, liver, nerves, lungs, and brain. Moreover, its effects include, but are not limited to, improving cardiovascular and cerebrovascular diseases, abirritation, regulating lipids, and treating cancer and diabetic complications. HSYA is widely recognised as an effective ingredient to treat cardiovascular and cerebrovascular diseases. Conclusion. SY has a wide range of pharmacological activities, among which improving cardiovascular and cerebrovascular diseases are the most significant.

Effects of Metformin on Renal Function, Cardiac Function, and Inflammatory Response in Diabetic Nephropathy and Its Protective Mechanism

Objective. To investigate the effect of metformin on renal function, cardiac function, and inflammatory response in diabetic nephropathy and its protective mechanism. Methods. A total of 88 patients with diabetic nephropathy who were admitted to our hospital from April 2019 to October 2020 were recruited and grouped according to different treatment methods, namely, the experimental group ( $n=44$ ) and the control group ( $n=44$ ). The patients in the experimental group were treated with metformin, and the patients in the control group were treated with liraglutide injection (nonmetformin). Left ventricular end-diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LVESD), and inflammatory response (hs-CRP, TNF-α, IL-6) were compared. Results. Compared with corresponding values before treatment, BUN, Scr, hs-CRP, TNF-α, IL-6, LVEDD, and LVESD were decreased after treatment, whereas LVEF was increased (all $P<0.05$ ), with significant change in the experimental group (all $P<0.001$ ). Conclusion. Metformin can effectively improve the level of renal function and cardiac function in patients with diabetic nephropathy and help patients control and reduce the body’s inflammatory response, and its therapeutic efficacy is superior to that of liraglutide injection.

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.

The effect of quercetin on diabetic nephropathy (DN): a systematic review and meta-analysis of animal studies

Quercetin, a flavonoid possessing numerous biological activities, is reported to improve renal injury in diabetic animals. Here, the aim of this systematic review and meta-analysis is to assess the effect of quercetin on diabetic nephropathy and summarize its possible mechanisms. We searched in four databases PubMed, Web of Sciences (WOS), Cochrane and Embase from inception to May 2021 and ultimately included 20 animal studies in this review. A total of 12 outcome measurements including renal function indexes, oxidative stress biomarkers and inflammatory cytokines were extracted for meta-analysis using RevMan 5.4 software. Apart from creatinine clearance and uric acid with no significant difference, quercetin significantly decreased the levels of renal index, serum/plasma creatinine (SCr), blood urea nitrogen (BUN), urine protein, urine albumin, malondialdehyde (MDA), tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and increased superoxide dismutase (SOD) and catalase (CAT) activity. In short, quercetin improves renal function and attenuates the renal oxidative stress level and inflammatory response in DN animal models. Its possible action mechanisms include anti-oxidation, anti-inflammation, anti-fibrosis, and regulation of renal lipid accumulation.

Long noncoding RNA X-inactive specific transcript regulates NLR family pyrin domain containing 3/caspase-1-mediated pyroptosis in diabetic nephropathy

BACKGROUND

NLRP3-mediated pyroptosis is recognized as an essential modulator of renal disease pathology. Long noncoding RNAs (lncRNAs) are active participators of diabetic nephropathy (DN). X inactive specific transcript (XIST) expression has been reported to be elevated in the serum of DN patients.

AIM

To evaluate the mechanism of lncRNA XIST in renal tubular epithelial cell (RTEC) pyroptosis in DN.

METHODS

A DN rat model was established through streptozotocin injection, and XIST was knocked down by tail vein injection of the lentivirus LV sh-XIST. Renal metabolic and biochemical indices were detected, and pathological changes in the renal tissue were assessed. The expression of indicators related to inflammation and pyroptosis was also detected. High glucose (HG) was used to treat HK2 cells, and cell viability and lactate dehydrogenase (LDH) activity were detected after silencing XIST. The subcellular localization and downstream mechanism of XIST were investigated. Finally, a rescue experiment was carried out to verify that XIST regulates NLR family pyrin domain containing 3 (NLRP3)/caspase-1-mediated RTEC pyroptosis through the microRNA-15-5p (miR-15b-5p)/Toll-like receptor 4 (TLR4) axis.

RESULTS

XIST was highly expressed in the DN models. XIST silencing improved renal metabolism and biochemical indices and mitigated renal injury. The expression of inflammation and pyroptosis indicators was significantly increased in DN rats and HG-treated HK2 cells; cell viability was decreased and LDH activity was increased after HG treatment. Silencing XIST inhibited RTEC pyroptosis by inhibiting NLRP3/caspase-1. Mechanistically, XIST sponged miR-15b-5p to regulate TLR4. Silencing XIST inhibited TLR4 by promoting miR-15b-5p. miR-15b-5p inhibition or TLR4 overexpression averted the inhibitory effect of silencing XIST on HG-induced RTEC pyroptosis.

CONCLUSION

Silencing XIST inhibits TLR4 by upregulating miR-15b-5p and ultimately inhibits renal injury in DN by inhibiting NLRP3/caspase-1-mediated RTEC pyroptosis.

Potential role of mitochondria-associated endoplasmic reticulum membrane proteins in diseases

Mitochondria-associated endoplasmic reticulum membranes (MAMs) are dynamic membrane coupling regions formed by the coupling of the mitochondrial outer membrane and endoplasmic reticulum (ER). MAMs are involved in the mitochondrial dynamics, mitophagy, Ca²⁺ exchange, and ER stress. A large number of studies indicate that many proteins are involved in the formation of MAMs, including dynamic-related protein 1 (Drp1), DJ-1, PTEN-induced putative kinase 1 (PINK), α-synuclein (α-syn), sigma-1 receptor (S1R), mitofusin-2 (Mfn2), presenilin-1 (PS1), protein kinase R (PKR)-like ER kinase (PERK), Parkin, Cyclophilin D (CypD), glucose-related protein 75 (Grp75), FUN14 domain containing 1 (Fundc1), vesicle-associated membrane-protein-associated protein B (VAPB), phosphofurin acidic cluster sorting protein 2 (PACS-2), ER oxidoreductin 1 (Ero1), and receptor expression-enhancing protein 1 (REEP1). These proteins play an important role in the structure and functions of the MAMs. Abnormalities in these MAM proteins further contribute to the occurrence and development of related diseases, such as neurodegenerative diseases, non-alcoholicfattyliverdisease (NALFD), type 2 diabetes mellitus (T2DM), and diabetic kidney (DN). In this review, we introduce important proteins involved in the structure and the functions of the MAMs. Furthermore, we effectively summarize major insights about these proteins that are involved in the physiopathology of several diseases through the effect on MAMs.

Characteristic of Streptozotocin-Nicotinamide-Induced Inflammation in A Rat Model of Diabetes-Associated Renal Injury

Background: Chemical agents such as streptozotocin (STZ) and nicotinamide (NAD) are used in animal models of diabetes mellitus and their related consequences in the kidneys. Several studies have been conducted to determine the modeling, however, the results are still unclear. Moreover, diabetic nephropathy is considered to begin with an inflammatory reaction in the kidneys.  Objectives: This study aims to investigate the metabolic profile STZ and NAD induce inflammation in the kidney.  Methods: The male Wistar rats used were divided into control and STZ-induced diabetes. Half of the diabetes group received a single dose of nicotinamide (230 mg/Kg) 15 minutes after STZ injection and all groups were monitored for 6 weeks. Furthermore, the profiles of creatinine, urea, and uric acid from serum and urine were observed and the kidney inflammation was tested by immunohistochemistry (IHC) with IL-6 and TNF-α parameters.  Results: The result shows that the administration of a single dose of 230 mg/kg NAD in diabetic rats induced with 50 mg/kg and 65 mg/kg STZ affects body weight and kidney organ index. For 6 weeks of testing, both doses of STZ were enhanced several parameters of kidney damage in diabetic rats in blood and urine chemical parameters. Furthermore, the use of NAD to promote inflammation in STZ-induced diabetic rats gave no significant difference. However, NAD can help mice live longer and avoid problems throughout the test.  Conclusions: The use of NAD leads to inflammation in Streptozotocin-induced diabetic rats. Therefore, the administration of Nicotinamide is recommended since it helps the rats live longer during the experiment. 

Circular RNAs in Diabetic Nephropathy: Updates and Perspectives

Circular RNAs (circRNAs) are widespread endogenous transcripts lacking 5′-caps and 3′-polyadenylation tails. Their closed-loop structure confers exonuclease resistance and extreme stability. CircRNAs play essential roles in various diseases, including diabetes. Diabetic nephropathy (DN) is the leading cause of end-stage kidney disease and is one of the most common complications of diabetes. CircRNAs are key in DN and therefore important for understanding DN pathophysiology and developing new therapeutic strategies. In the present review, we briefly introduce the characteristics and functions of circRNAs and summarize recent discoveries on how circRNAs participate in DN. Based on these advances, we suggest future perspectives for studying circRNAs in DN to improve DN treatment and management.

Comprehensive Diagnostics of Diabetic Nephropathy by Transcriptome RNA Sequencing

BACKGROUND

Diabetic nephropathy (DN) is a primary driver of end-stage renal disease. Given the heterogeneity of renal lesions and the complex mechanisms of DN, the present-day diagnostic approach remains highly controversial. We aimed to design a diagnostic model by bioinformatics methods for discriminating DN patients from normal subjects.

METHODS

In this study, transcriptome sequencing was performed on 6 clinical samples (3 from DN patients and 3 from healthy volunteers) from the Second Affiliated Hospital of Kunming Medical University. Construction of a competing endogenous RNA (ceRNA) network based on differentially expressed (DE)-mRNAs and -long noncoding RNAs (lncRNAs). Subsequently, the CytoHubba plugin was used to identify hub genes from DE-mRNAs in the ceRNA network and to perform functional enrichment analysis on them. The least absolute shrinkage and selection operator (LASSO) regression analysis was responsible for screening the diagnostic biomarkers from hub genes and assessing their diagnostic power using ROC curves. The pathways involved in hub genes were revealed by single-gene Gene Set Enrichment Analysis (GSEA). Moreover, we verified the expression levels of diagnostic biomarkers by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot.

RESULTS

A total of 10 hub genes were screened from the ceRNA network, which appeared to be associated with the viral infection, kidney development, and regulation of immune and inflammatory responses. Subsequently, LASSO regression analysis established a diagnostic model consisting of DDX58, SAMD9L, and TLR6 with a robust diagnostic potency (AUC = 1). Similarly, single-gene GSEA showed a strong association of these diagnostic biomarkers with the viral infection. Furthermore, PCR and Western blot demonstrated showed that DDX58, SAMD9L, and TLR6 were upregulated in DN patients at both transcriptome and protein levels compared to healthy controls.

CONCLUSION

We confirmed that differentially expressed hub genes may be novel diagnostic biomarkers in DN.

Increased Serum VEGF-B Level Is Associated With Renal Function Impairment in Patients With Type 2 Diabetes

AIMS/INTRODUCTION

Renal function impairment related to type 2 diabetes (T2DM) presents serious threat to public health. Previous studies suggest that vascular endothelial growth factor-B (VEGF-B) might contribute to renal injury. Therefore, this study investigated the association of serum VEGF-B level with the risk of renal function impairment in T2DM patients.

MATERIALS AND METHODS

Serum VEGF-B levels were measured in 213 patients with type 2 diabetes and 31 healthy participants. Participants with type 2 diabetes were further divided into a group of 112 participants with eGFR<90 mL/min/1.73m² and 101 participants with eGFR≥ 90 mL/min/1.73m². Clinical data were collected, and a binary logistic regression model was employed to test the association between potential predictors and eGFR.

RESULTS

Serum VEGF-B levels evaluated in type 2 diabetes patients compared with healthy controls. In patients with type 2 diabetes, serum VEGF-B level was positively correlated with triglyceride, serum creatinine and cystatin C while negatively correlated with HDL-C and eGFR. Binary logistic regression showed that serum VEGF-B level was an independent risk factor of eGFR<90 mL/min/1.73m².

CONCLUSIONS

Serum VEGF-B level is associated with renal function impairment in patients with type 2 diabetes and may be a potential drug target for diabetic kidney disease.

Urinary Transferrin and Proinflammatory Markers Predict the Earliest Diabetic Nephropathy Onset

This study aimed to determine the earliest markers of diabetic nephropathy (DN) onset with discriminative potentials from controlled diabetes (CD). Methods: Sixty male Wistar rats were allocated in three groups (20/group), the two diabetic groups CD and DN received 45 and 65 mg/kg STZ in 0.1 mole/L citrate buffer; respectively, while control group received only the vehicle. Serum/urinary levels of glomerular, tubular, oxidative and proinflammatory markers were weekly monitored. Results: Each diabetic group showed a different pattern of inflammatory; oxidative and signs of nephropathy along the study period, but none had a discriminative power until the 4^th week. At this time point, levels of urinary transferrin; serum/urinary IL-6 and TNF-α as well as urinary IL-18 were significantly higher in DN group comparing to CD (P = 0.0217, <0.0001, 0.0005, 0.0004, 0.0006, 0.0019; respectively). Predictive thresholds of these markers were calculated by receiver operating characteristic (ROC) curve that showed area under curve (AUC) of 0.9375 for transferrin with cut-off value 35.2 mg/dL, and 1.000 for serum/urinary IL-6 and TNF-α and urinary IL-18 with cut-of values 224.1, 82.11, 6.596, 125.9 and 21.86 pg/mL; respectively. Conclusion: Urinary transferrin and the inflammatory endpoints proposed in this study might represent promising biomarkers for the early DN onset.

Acute and subacute oral toxicity of propylene glycol enantiomers in mice and the underlying nephrotoxic mechanism

Propylene glycol (PG; 1,2-propanediol) has been commonly used as a food additive and vehicle in pharmaceutical preparations. PG can form rectus (R-) enantiomers and sinister (S-) enantiomers. Herein, Kunming mice were used as the animal model to evaluate the acute and subacute oral toxicity of R-PG, S-PG and RS-PG (1:1 racemic mixture of R-PG and S-PG). The median lethal doses of R-PG, S-PG and RS-PG administered by oral gavage to mice were 22.81 g/kg, 26.62 g/kg and 24.92 g/kg, respectively. In the 28-day oral subacute toxicity study, the body weight, organ weights, serum biochemical, and renal histology were examined. There was no difference in subacute toxicity among R-PG, S-PG and RS-PG. The administration of 1 and 5 g/kg/day PG for 28 days caused nephrotoxicity. The kidney somatic index and levels of blood urea nitrogen exhibited a significant increase. Moreover, the activities of superoxide dismutase, catalase, and glutathione peroxidase significantly decreased after the treatment with PG. The levels of malondialdehyde, tumor necrosis factor α, interleukin 1β, and interleukin 6 significantly increased in the kidney. The results show that the nephrotoxic effects of PG are induced by oxidative stress, and the activation of the inflammatory response is mediated by the NF-κB signaling pathway. Together, these findings provide information on R-PG, S-PG and RS-PG treatments for the risk assessment of toxicity and effects on human health.

CircSMAD4 alleviates high glucose-induced inflammation, extracellular matrix deposition and apoptosis in mouse glomerulus mesangial cells by relieving miR-377-3p-mediated BMP7 inhibition

BACKGROUND

Diabetic nephropathy (DN) is a common complication of diabetes mellitus. Accumulating studies suggest that the deregulation of circular RNA (circRNA) is involved in DN pathogenesis. This study aimed to investigate the role of circSMAD4 in DN models.

METHODS

Mice were treated with streptozotocin to establish DN models in vivo. Mouse glomerulus mesangial cells (SV40-MES13) were treated with high glucose to establish DN models in vitro. The expression of circSMAD4, miR-377-3p and bone morphogenetic protein 7 (BMP7) mRNA was measured by quantitative real-time PCR (qPCR). The releases of inflammatory factors were examined by ELISA. The protein levels of fibrosis-related markers, apoptosis-related markers and BMP7 were checked by western blot. Cell apoptosis was monitored by flow cytometry assay. The predicted relationship between miR-377-3p and circSMAD4 or BMP7 was validated by dual-luciferase reporter assay or pull-down assay.

RESULTS

CircSMAD4 was poorly expressed in DN mice and HG-treated SV40-MES13 cells. HG induced SV40-MES13 cell inflammation, extracellular matrix (ECM) deposition and apoptosis. CircSMAD4 overexpression alleviated, while circSMAD4 knockdown aggravated HG-induced SV40-MES13 cell injuries. MiR-377-3p was targeted by circSMAD4, and miR-377-3p enrichment partly reversed the effects of circSMAD4 overexpression. BMP7 was a target of miR-377-3p, and circSMAD4 regulated BMP7 expression by targeting miR-377-3p. MiR-377-3p overexpression aggravated HG-induced injuries by suppressing BMP7.

CONCLUSION

CircSMAD4 alleviates HG-induced SV40-MES13 cell inflammation, ECM deposition and apoptosis by relieving miR-377-3p-mediated inhibition on BMP7 in DN progression.

Re-thinking diabetic nephropathy: Microalbuminuria is just a piece of the diagnostic puzzle

The decline of the estimated glomerular filtration rate (eGFR) and the presence of albuminuria are the typical hallmarks of kidney disease arising as one of the most frequent diabetic complications over a long period of time, generally known as diabetic nephropathy or diabetes kidney disease (DKD). However, a decline in the renal function may occur in diabetic patients for other reasons unrelated to glycemic control, and this condition is known as non-diabetic kidney disease (NDKD). In this opinion paper we will review these conditions, and we outline the importance of other investigations, such as kidney biopsy and the measurement of novel biomarkers, in order to identify the disease progression early, and to allow a timely intervention. We will also focus on the actual limits of the quantitative measurements of albumin in urine, especially with regards to potential interferences due to the treatment of patients with statins.

Diabetic Nephropathy - possibilities of early laboratory diagnostics and course prediction (review of literature)

The medical and social significance of diabetes mellitus is determined by a progressive increase in the incidence of the disease, as well as the development of disabling and reducing the quality of life of macro- and microvascular complications in patients of working age, in particular, with the development of diabetic nephropathy (DN), which develops in one third of patients with type 1 and 2 diabetes. DN is the third leading cause of death after diseases of the cardiovascular system and oncological pathologies. In this regard, the identification of DN at the early stages is an important task both from the standpoint of prevention and a more favorable prognosis of the course of diabetes. This review presents data on the possibilities of early diagnosis of DN using blood and urine biomarkers, as well as information on their diagnostic and prognostic value. The analysis of the interpretation of the indicator of microalbuminuria in type 1 and 2 diabetes was carried out. In addition, the literature data of recent years on the informative value of determining markers of podocyte damage, on the role of oxidative stress products, immune-inflammatory factors, and vascular endothelial growth factor in the process of the onset and development of DN are presented. The possibility of their practical use for the diagnosis of DN in clinical practice is discussed. The literature search for this review was carried out using the databases of the RSCI, CyberLeninka, Scopus, Web of Science, MedLine, PubMed for the period from 2011 to 2021. using the following keywords: diabetes mellitus, diabetic nephropathy, markers of diabetic nephropathy; kidney damage, early diagnosis of diabetic nephropathy.

Long non-coding RNA TTC28-AS1 attenuates high glucose-induced damage in HK-2 cells depending on the regulation of miR-320a/CD2AP axis

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) worldwide. Emerging evidence suggests that long non-coding RNAs (lncRNAs) play crucial roles in DN pathogenesis.

OBJECTIVE

The purpose of the present study was to explore the role and mechanism of lncRNA tetratricopeptide repeat domain 2B antisense RNA 1 (TTC28-AS1) in DN.

METHODS

Cell viability and apoptosis were assessed by the Cell Counting-8 Kit (CCK-8) assay and flow cytometry, respectively. The levels of TTC28-AS1, miR-320a and CD2-associated protein (CD2AP) were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. The levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-8 were gauged by enzyme-linked immunosorbent assay (ELISA). Targeted relationship between miR-320a and TTC28-AS1 or CD2AP was evaluated by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays.

RESULTS

Our data indicated that high glucose (HG) induced HK-2 cell damage by the repression of cell viability and autophagy and the enhancement of cell apoptosis, fibrosis and pro-inflammatory cytokines production. TTC28-AS1 was down-regulated and miR-320a was up-regulated in HG-induced HK-2 cells. TTC28-AS1 overexpression or miR-320a knockdown alleviated HG-induced damage in HK-2 cells. MiR-320 was a molecular mediator of TTC28-AS1 in regulating HG-induced HK-2 cell damage. Moreover, TTC28-AS1 functioned as a post-transcriptional regulator of CD2AP expression by miR-320a. MiR-320a knockdown relieved HG-induced damage in HK-2 cells by up-regulating CD2AP.

CONCLUSIONS

Our findings suggest that TTC28-AS1 attenuates HG-induced damage in HK-2 cells at least partially by targeting the miR-320a/CD2AP axis, highlighting its role as a promising therapeutic approach for DN treatment.

Apelin‑13 alleviates diabetic nephropathy by enhancing nitric oxide production and suppressing kidney tissue fibrosis

Diabetes is a serious metabolic disease, and the kidney damage induced by diabetes also seriously affects the survival of patients. Apelin is a molecule that plays a crucial role in lipid metabolism, and recent studies have revealed that apelin-13, a subtype of apelin, plays an important role in regulating blood glucose levels. However, the role of apelin-13 in diabetic nephropathy remains unclear. In the present study, a rat model of diabetic nephropathy was constructed by the injection of streptozocin (STZ). During this process, these rats were injected with apelin-13. The blood glucose, urine protein and insulin levels were determined weekly. Next, the expression of angiotensin domain type 1 receptor-associated protein (APJ), endothelial nitric oxide synthase (eNOS), E-cadherin and α-smooth muscle actin (α-SMA) in the kidney tissues was determined with western blotting. Then, the endothelial cells of glomerular vessels were cultured with high glucose medium. These cells were treated with apelin-13 for 24 h. Finally, cell viability of these cells and the expression of APJ, eNOS, E-cadherin and α-SMA in these cells were determined with western blotting. As a result, treatment of apelin-13 induced the lower levels of blood glucose and urine protein. In addition, application of apelin-13 promoted the production of insulin and alleviated the insulin resistance. Treatment with apelin-13 promoted the expression of APJ, eNOS and E-cadherin while it suppressed the expression of α-SMA in kidney tissues of rats and endothelial cells of glomerular vessels. Furthermore, application of apelin-13 also promoted the cell viability of these cells. In conclusion, apelin-13 relieved diabetic nephropathy by promoting the production of nitric oxide (NO) and alleviating the fibrosis of kidney tissues.

High risk of tubular damage in normoalbuminuric adults with type 2 diabetes for over 14 years

Highlights The level of urinary α₁ -microglobulin to creatinine ratio (A1MCR) increases with longer diabetes duration. Patients with a diabetes duration >14 years have a higher tubular damage rate. Being male and a diabetes duration >14 years have an interaction effect on increased A1MCR.

Risk factors associated with renal crescentic formation in pediatric Henoch-Schönlein purpura nephritis: a retrospective cohort study

BACKGROUND

The long-term prognosis of Henoch-Schönlein purpura (HSP) depends on the severity of renal involvement, and crescent formation is considered an important risk factor for poor prognosis of Henoch-Schönlein purpura nephritis (HSPN). The objective of this study was to evaluate factors affecting crescent formation in children with HSPN.

METHODS

Demographic factors, clinical characteristics, and laboratory data of children with HSPN with or without crescents were retrospectively analyzed. Univariate and multivariate logistic regression analyses were used to determine the risk factors of crescent formation in HSPN.

RESULTS

A total of 191 children with HSPN were enrolled in the study. There were 107 (56%) males and 84 (44%) females, with a median age of 7 years (range: 2 years-15 years). International Study of Kidney Disease in Children (ISKDC) grading was used to divide subjects into two groups: those without glomerular crescent formation (ISKDC grades I-II, n = 146 cases) and those with glomerular crescent formation (ISKDC grades III-V, n = 45 cases). Logistic regression analysis showed that higher urinary white blood cell (WBC) count (OR = 3.300; 95% CI, 1.119-9.739; P = 0.0306) and higher urinary microalbumin/creatinine ratio (ACR) (OR = 25.053; 95% CI, 1.354-463.708; P = 0.0305) were independent risk factors for the formation of crescents in HSPN. The area under the receiver operating characteristic curve of urinary WBC and ACR were 0.753 and 0.698 respectively, with the Hosmer and Lemeshow goodness-of-fit test (P = 0.0669, P > 0.05).

CONCLUSION

These results suggest that higher urinary WBC count and ACR should be strictly monitored for children with HSPN. Adequate clinical intervention for these risk factors may limit or prevent renal crescent formation.