Diabetic nephropathy: diagnosis, prevention, and treatment

Epidemiological characteristics of diabetic kidney disease in Taiwan

Diabetic kidney disease (DKD) is a critical microvascular complication of diabetes. With the continuous increase in the prevalence of diabetes since 2000, the prevalence of DKD has also been increasing in past years. The prevalence of DKD among individuals with type 2 diabetes in Taiwan increased from 13.32% in 2000 to 17.92% in 2014. The cumulative incidence of DKD among individuals with type 1 diabetes in Taiwan was higher than 30% during 1999-2012. DKD is the leading cause of end-stage renal disease (ESRD), with a prevalence of approximately 45% in a population on chronic dialysis in Taiwan. Among individuals with type 2 diabetes, the prevalence of ESRD in the receipt of dialysis also increased from 1.32% in 2005 to 1.47% in 2014. Risk factors for DKD development are age, race, family history, hyperglycemia, hypertension, dyslipidemia, dietary patterns, and lifestyles. Prognostic factors that aggravate DKD progression include age, family history, sex, glycemic control, blood pressure (BP), microvascular complications, and atherosclerosis. This review summarizes updated information on the onset and progression of DKD, particularly in the Taiwanese population. Translating these epidemiological features is essential to optimizing the kidney care and improving the prognosis of DKD in Asian populations.

Review of early circulating biomolecules associated with diabetes nephropathy - Ideal candidates for early biomarker array test for DN

BACKGROUND

Diabetic nephropathy (DN) is one of the catastrophic complications of type 2 diabetes mellitus (T2DM). 45% of DN patients progressed to End Stage Renal Disease (ESRD) which robs casualties of the quality of live. The challenge in early diagnosis of DN is it is asymptomatic in the early phase. Current gold standard test for screening and diagnosis of DN are nonspecific and are not sensitive in detecting DN early enough and subsequently monitor renal function during management and intervention plans. Recent studies reported various biomolecules which are associated with the onset of DN in T2DM using cutting-edge technologies. These biomolecules could be potential early biomarkers for DN. This review selectively identified potential early serum biomolecules which are potential candidates for developing an Early Biomarker Array Test for DN.

METHODS

An advanced literature search was conducted on 4 online databases. Search terms used were "Diabetes Mellitus, Type 2", "Diabetic nephropathy", "pathogenesis" and "early biomarker. Filters were applied to capture articles published from 2010 to 2020, written in English, human or animal models and focused on serum biomolecules associated with DN.

RESULTS

Five serum biomolecules have been evidently described as contributing pivotal roles in the pathophysiology of DN. MiR-377, miR-99b, CYP2E1, TGF-β1 and periostin are potential candidates for designing an early biomarker array for screening and diagnosis of early stages of DN. The five shortlisted biomolecules originates from endogenous biochemical processes which are specific to the progressive pathophysiology of DN.

CONCLUSION

miR-377, miR-99b, CYP2E1, TGF-β1 and periostin are potential candidate biomolecules for diagnosing DN at the early phases and can be developed into a panel of endogenous biomarkers for early detection of DN in patients with T2DM. The outcomes of this study will be a stepping stone towards planning and developing an early biomarker array test for diabetic nephropathy. The proposed panel of early biomarkers for DN has potential of stratifying the stages of DN because each biomolecule appears at distinct stages in the pathophysiology of DN.

Single and joint impact of type 2 diabetes and of congestive heart failure on albuminuria

AIMS

Albuminuria is a characteristic feature of diabetic nephropathy, and urine albumin excretion is also increased in patients with congestive heart failure (CHF). However, no data are available on the single and joint associations of type 2 diabetes mellitus (T2DM) and CHF with albuminuria. This issue was addressed in the present study.

METHODS

We investigated 4 groups of patients: 180 patients with CHF, of whom 83 had T2DM (CHF+/T2DM+) and 97 did not have diabetes (CHF+/T2DM-) and 223 controls without CHF, of whom 39 had T2DM (CHF-/T2DM+) and 184 did not have diabetes (CHF-/T2DM-).

RESULTS

The albumin-creatinine ratio (ACR) was 9.2 [5.7-16.9] mg/g in CHF-/T2DM- patients. Compared to this group it was higher in CHF-/T2DM+ patients (16.1 [7.7-27.8] mg/g; p = 0.004), in CHF+/T2DM- patients (22.0 [9.0-76.8] mg/g; p < 0.001) and in CHF+/T2DM+ patients (66.2 [16.0-177.0] mg/g; p < 0.001), in whom in turn it was higher than in CHF-/T2DM+ (p < 0.001) or in CHF+/T2DM- (p = 0.001) patients. The ACR did not differ significantly between CHF-/T2DM+ and CHF+/T2DM- patients (p = 0.188). In multivariate analysis of covariance, CHF and T2DM proved to be independent predictors of ACR after multivariate adjustment (F = 5.68; p = 0.018 and F = 4.79; p = 0.029, respectively).

CONCLUSIONS

We conclude that T2DM and CHF are mutually independent determinants of albuminuria.

Machine learning approach to predicting albuminuria in persons with type 2 diabetes: An analysis of the LOOK AHEAD Cohort

Albuminuria and estimated glomerular filtration rate (e-GFR) are early markers of renal disease and cardiovascular outcomes in persons with diabetes. Although body composition has been shown to predict systolic blood pressure, its application in predicting albuminuria is unknown. In this study, we have used machine learning methods to assess the risk of albuminuria in persons with diabetes using body composition and other determinants of metabolic health. This study is a comparative analysis of the different methods to predict albuminuria in persons with diabetes mellitus who are older than 40 years of age, using the LOOK AHEAD study cohort-baseline characteristics. Age, different metrics of body composition, duration of diabetes, hemoglobin A1c, serum creatinine, serum triglycerides, serum cholesterol, serum HDL, serum LDL, maximum exercise capacity, systolic blood pressure, diastolic blood pressure, and the ankle-brachial index are used as predictors of albuminuria. We used Area under the curve (AUC) as a metric to compare the classification results of different algorithms, and we show that AUC for the different models are as follows: Random forest classifier-0.65, gradient boost classifier-0.61, logistic regression-0.66, support vector classifier -0.61, multilayer perceptron -0.67, and stacking classifier-0.62. We used the Random forest model to show that the duration of diabetes, A1C, serum triglycerides, SBP, Maximum exercise Capacity, serum creatinine, subtotal lean mass, DBP, and subtotal fat mass are important features for the classification of albuminuria. In summary, when applied to metabolic imaging (using DXA), machine learning techniques offer unique insights into the risk factors that determine the development of albuminuria in diabetes.

Effect of Enhydra fluctuans on Kidney Function in Alloxan-induced Diabetic Rats

AIM: The aim of this study was to explore the effect of n-hexane fraction of Enhydra fluctuans aerial on kidney function in alloxan induced diabetic rats. METHODS: Five groups of diabetic Wistar rats were studied: Group 1 was given 0.5% Na-CMC (G0), group 2 was given glibenclamide 0.45 mg/kg (G1), groups 3, 4, and 5 were given a dose of n-hexane fraction 57.03, 114.06, and 171.09 mg/kg respectively. The experiment was completed in 21 days. Blood glucose was estimated on day 0 and day 21 of treatment. Histology of kidney, creatinine, and blood urea nitrogen (BUN) was examined. ANOVA was used to evaluate quantitative data, which was then followed by Duncan's new multiple range test (p < 0.05). RESULTS: Our results demonstrate that n-hexane fraction dosages of 57.03 mg/kg and 114,06 mg/kg significantly improved blood glucose profile, BUN, and creatinine in diabetic rats. Moreover, the dosage of 57.03 mg/kg is effective to counteract necrosis and fibrosis of kidney cells.   CONCLUSION: Our findings revealed that the administration of the n-hexane fraction of E. fluctuans aerial improved the kidney function of diabetic rats, especially at the dosage of 57.03 mg/kg. Therefore, E. fluctuans can be relied upon to be a drug to prevent the development of diabetes mellitus and diabetic nephropathy.

Adjuvant physical exercise for the management of painful polyneuropathy

INTRODUCTION

Physical exercise appeared to be effective, when implemented as an adjuvant to the pharmacotherapy option, in a variety of painful conditions. Peripheral neuropathic pain (PNP) is very prevalent and affects up to two-thirds of individuals with polyneuropathy (PN), regardless of etiology. The aim of this systematic review was to evaluate the currently available studies that assess adjuvant physical exercise for the management of PNP.

METHODS

A systematic literature search was conducted in the PubMed international database. For the systematic search, three medical subject headings (MeSH) were used. Term A was 'physical exercise' OR 'exercise' OR 'activity' OR 'workout' OR 'training'; term B was 'pain' OR 'painful'; term C was 'neuropathy' OR 'polyneuropathy.' Additionally, three filters were used: human subjects, English language, and full text. The reference lists of eligible papers and relevant reviews were also meticulously searched in order to include further relevant studies. Six papers eligible to be included were identified.

RESULTS

Physical exercise in various forms can be of benefit in the management of PNP when used as an adjuvant to the standard care. Overall, using the American Society of Interventional Pain Physicians (ASIPP) criteria, the current best available evidence exists for both aerobic and muscle strengthening exercise programs (level II evidence). The intensity of the exercise seems to play a significant role, with higher intensity interval training programs being more promising, though this remains to be confirmed in future studies.

CONCLUSIONS

Physical exercise is a promising non-pharmacological intervention for the management of PNP. Future RCTs should be conducted to make a face-to-face comparison of the available exercise treatments with the aim to design specific exercise programs for patients with PNP.

How Economic Analysis Increases the Awareness of Clinical Services: A Case of Diabetes Mellitus at a Teaching Hospital in Myanmar

OBJECTIVES

Myanmar faces a growing epidemic of type 2 diabetes mellitus, which has significant impact on the individual health and health service system; nevertheless, reliable cost estimate for treating diabetes is still unknown. Therefore, this study aimed to explore the treatment cost of hospitalization by type 2 diabetes mellitus and the association of complications and comorbidities with the treatment cost.

METHODS

The retrospective incidence-based cost of illness analysis was performed at the diabetes ward of 800-bed teaching hospital in Yangon, Myanmar. The data were retrieved from hospital financial reports and patient's medical records for the fiscal year 2017 to 2018. Data was analyzed by using descriptive statistics and multivariate statistics. One-way sensitivity analysis was used to assess the uncertainty of input parameters.

RESULTS

This study involved 87 inpatients with type 2 diabetes mellitus with an average length of stay of 16.1 ± 12.6 days. Of the study sample, 67% had complications whereas 74% had comorbidities. The average treatment cost per admission was $718.7 (equal to 58% of gross domestic product - GDP per capita) at 2018 prices. Based on the multiple regression analysis, cost savings per admission were $276.5, $307.3, and $319.5 from preventing foot ulcer, nephropathy, and retinopathy, respectively.

CONCLUSIONS

This study found that the treatment of diabetes is costly because of its preventable health consequences. Better disease management to prevent complications results in considerable cost savings. This quantitative evidence would increase awareness in health service system.

Anti-fibrotic effect of 6-bromo-indirubin-3'-oxime (6-BIO) via regulation of activator protein-1 (AP-1) and specificity protein-1 (SP-1) transcription factors in kidney cells

PAI-1 and CTGF are overexpressed in kidney diseases and cause fibrosis of the lungs, liver, and kidneys. We used a rat model of unilateral ureteral obstruction (UUO) to investigate whether 6-BIO, a glycogen synthase kinase-3β inhibitor, attenuated fibrosis by inhibiting PAI-1 and CTGF in vivo. Additionally, TGFβ-induced cellular fibrosis was observed in vitro using the human kidney proximal tubular epithelial cells (HK-2), and rat interstitial fibroblasts (NRK49F). Expression of fibrosis-related proteins and signaling molecules such as PAI-1, CTGF, TGFβ, αSMA, SMAD, and MAPK were determined in HK-2 and NRK49F cells using immunoblotting. To identify the transcription factors that regulate the expression of PAI-1 and CTGF the promoter activities of AP-1 and SP-1 were analyzed using luciferase assays. Confocal microscopy was used to observe the co-localization of AP-1 and SP-1 to PAI-1 and CTGF. Expression of PAI-1, CTGF, TGFβ, and α-SMA increased in UUO model as well as in TGFβ-treated HK-2 and NRK49F cells. Furthermore, UUO and TGFβ treatment induced the activation of P-SMAD2/3, SMAD4, P-ERK 1/2, P-P38, and P-JNK MAPK signaling pathways. PAI-1, CTGF, AP-1 and SP-1 promoter activity increased in response to TGFβ treatment. However, treatment with 6-BIO decreased the expression of proteins and signaling pathways associated with fibrosis in UUO model as well as in TGFβ-treated HK-2 and NRK49F cells. Moreover, 6-BIO treatment attenuated the expression of PAI-1 and CTGF as well as the promoter activities of AP-1 and SP-1, thereby regulating the SMAD and MAPK signaling pathways, and subsequently exerting anti-fibrotic effects on kidney cells.

PPBP as a marker of diabetic nephropathy podocyte injury via Bioinformatics Analysis

Diabetic nephropathy (DN) is a type of kidney injuries associated with diabetes mellitus and the prevalence of DN has increased dramatically. However, DN still pose problems in therapy, and prognosis. Identifying new DN biomarkers would be helpful in reducing morbidity and mortality from DN and developing novel preventive approaches. In the study, from GSE36336 dataset with DN glomeruli samples, we screened for 238 differentially expressed genes. Enrichment analysis were performed to find out biological function and diseases of DEGs. Next, depended on protein-protein interaction network, We identified top 10 hub genes (Serpine1, Cxcl10, Cfd, Ppbp, Retn, Socs2, Ccr5, Mmp8, Pf4, Cxcl9) may played potential roles in DN. Meanwhile, transcriptome sequencing on podocyte were performed to reconfirm the reliability of Ppbp. To verify the efficiency of the selected genes as biomarkers, several experiments like qRT-PCR, renal histologic analysis and immunofluorescence were conducted to validate. Our results showed that PPBP have the potential to become a novel biomarker for DN podocyte injury.

Spatial-resolved metabolomics reveals tissue-specific metabolic reprogramming in diabetic nephropathy by using mass spectrometry imaging

Detailed knowledge on tissue-specific metabolic reprogramming in diabetic nephropathy (DN) is vital for more accurate understanding the molecular pathological signature and developing novel therapeutic strategies. In the present study, a spatial-resolved metabolomics approach based on air flow-assisted desorption electrospray ionization (AFADESI) and matrix-assisted laser desorption ionization (MALDI) integrated mass spectrometry imaging (MSI) was proposed to investigate tissue-specific metabolic alterations in the kidneys of high-fat diet-fed and streptozotocin (STZ)-treated DN rats and the therapeutic effect of astragaloside IV, a potential anti-diabetic drug, against DN. As a result, a wide range of functional metabolites including sugars, amino acids, nucleotides and their derivatives, fatty acids, phospholipids, sphingolipids, glycerides, carnitine and its derivatives, vitamins, peptides, and metal ions associated with DN were identified and their unique distribution patterns in the rat kidney were visualized with high chemical specificity and high spatial resolution. These region-specific metabolic disturbances were ameliorated by repeated oral administration of astragaloside IV (100 mg/kg) for 12 weeks. This study provided more comprehensive and detailed information about the tissue-specific metabolic reprogramming and molecular pathological signature in the kidney of diabetic rats. These findings highlighted the promising potential of AFADESI and MALDI integrated MSI based metabolomics approach for application in metabolic kidney diseases.

Alleviation of diabetic nephropathy by zinc oxide nanoparticles in streptozotocin-induced type 1 diabetes in rats

This study examines the effect of nanoparticles with zinc oxides (ZnONPs) on diabetic nephropathy, which is the primary cause of mortality for diabetic patients with end‐stage renal disease. Diabetes in adult male rats was induced via intraperitoneal injection of streptozotocin. ZnONPs were intraperitoneally administered to diabetic rats daily for 7 weeks. Diabetes was associated with increases in blood glucose level, 24‐h urinary albumin excretion rate, glomerular basement membrane thickness, renal oxidative stress markers, and renal mRNA or protein expression of transforming growth factor‐β1, fibronectin, collagen‐IV, tumour necrosis factor‐α and vascular endothelial growth factor‐A. Moreover, the expression of nephrin and podocin, and the mRNA expression of matrix metalloproteinase‐9 were decreased in the diabetic group. These changes were not detected in the control group and were significantly prevented by ZnONP treatment. These results provide evidence that ZnONPs ameliorate the renal damage induced in a diabetic rat model of nephropathy through improving renal functionality; inhibiting renal fibrosis, oxidative stress, inflammation and abnormal angiogenesis; and delaying the development of podocyte injury. The present findings may help design the clinical application of ZnONPs for protection against the development of diabetic nephropathy.

T1DMicro: A Clinical Risk Calculator for Type 1 Diabetes Related Microvascular Complications

Development of complications in type 1 diabetes patients can be reduced by modifying risk factors. We used a cross-sectional cohort of 1646 patients diagnosed with type 1 diabetes (T1D) to develop a clinical risk score for diabetic peripheral neuropathy (DPN), autonomic neuropathy (AN), retinopathy (DR), and nephropathy (DN). Of these patients, 199 (12.1%) had DPN, 63 (3.8%) had AN, 244 (14.9%) had DR, and 88 (5.4%) had DN. We selected five variables to include in each of the four microvascular complications risk models: age, age of T1D diagnosis, duration of T1D, and average systolic blood pressure and HbA1C over the last three clinic visits. These variables were selected for their strong evidence of association with diabetic complications in the literature and because they are modifiable risk factors. We found the optimism-corrected R2 and Harrell’s C statistic were 0.39 and 0.87 for DPN, 0.24 and 0.86 for AN, 0.49 and 0.91 for DR, and 0.22 and 0.83 for DN, respectively. This tool was built to help inform patients of their current risk of microvascular complications and to motivate patients to control their HbA1c and systolic blood pressure in order to reduce their risk of these complications.

The broad pathogenetic role of TCF7L2 in human diseases beyond type 2 diabetes

The TCF7L2 protein is a key transcriptional effector of the Wnt/β‐catenin signaling pathway, regulating gene expression. It was initially identified in cancer research and embryologic developmental studies. Later, the TCF7L2 gene was linked to type 2 diabetes (T2D), implicating TCF7L2 and Wnt‐signaling in metabolic disorders and homeostasis. In fact, TCF7L2‐T2D variants confer the greatest relative risk for T2D, unquestionably predicting conversion to T2D in individuals with impaired glucose tolerance. We aim to describe the relevance of TCF7L2 in other human disorders. The TCF7L2‐single nucleotide polymorphisms (SNPs) and T2D‐risk association have been replicated in numerous follow‐up studies, and research has now been performed in several other diseases. In this article, we discuss common TCF7L2‐T2D variants within the framework of their association with human diseases. The TCF7L2 functional regions need to be further investigated because the molecular and cellular mechanisms through which TCF7L2 contributes to risk associations with different diseases are still not fully elucidated. In this review, we show the association of common TCF7L2‐T2D variants with many types of diseases. However, the role of rare genetic variations in the TCF7L2 gene in distinct diseases and ethnic groups has not been explored, and understanding their impact on specific phenotypes will be of clinical relevance. This offers an excellent opportunity to gain a clearer picture of the role that the TCF7L2 gene plays in the pathophysiology of human diseases. The potential pleiotropic role of TCF7L2 may underlie a possible pathway for comorbidity in human disorders.

Elevated Serum Levels of Carbohydrate Antigen 72-4 in Diabetic Kidney Disease

The aim of this study was to determine whether carbohydrate antigen 72-4 (CA72-4) is elevated in diabetic kidney disease (DKD), and examine the association between urinary albumin-to-creatinine ratio (UACR) and CA72-4 in patients with type 2 diabetes mellitus (T2DM). Non-dialysis patients with T2DM (n=296) and 90 healthy controls were recruited in this study. CA72-4 level was measured by electrochemiluminescence immunoassay. DKD was defined as UACR≥ 30 mg/g in the absence of a urinary infection or other renal diseases. We found that patients with DKD had significantly higher serum CA72-4 levels compared to those with normoalbuminuria and healthy controls. Positive rates of CA72-4 increased gradually and markedly from normoalbuminuria to microalbuminuria and to macroalbuminuria in diabetic patients (7.5, 11.2, and 17.4%, respectively; P for trend< 0.05). CA72-4 also showed a positive correlation with UACR (r=0.288, P< 0.01). Logistic regression analysis revealed the association of increased UACR with an increased odds ratio of elevation of CA72-4 levels (P for trend< 0.05) after multivariable adjustment. In conclusion, serum levels of CA72-4 increase abnormally with the increase in urinary albumin excretion, which affects the specificity of diagnosis of malignancies. An appropriate interpretation of CA72-4 is essential to prevent unnecessary and even hazardous diagnostic procedures in patients with T2DM.

Value of Doppler ultrasound in early detection of diabetic kidney disease: A systematic review and meta-analysis

The diagnosis of diabetic kidney disease can be delayed by limitations of primary biomarkers, which are microalbuminuria and estimated glomerular filtration rate. A number of Doppler ultrasound studies have associated an increase in intrarenal vascular resistance with the disease, which makes ultrasound a potential adjunct tool for early diagnosis. However, there is inadequate evidence to establish the effectiveness of including Doppler ultrasound in the diagnostic process. This systematic review was therefore conducted to determine the value of using Doppler ultrasound in early detection of diabetic kidney disease. Electronic literature searches were carried out in PubMed, CINAHL, Web of Science and EMBASE. All published prospective studies with records of intrarenal Doppler ultrasound, microalbuminuria and estimated glomerular filtration rate were obtained, and their relationship as parameters for diabetic kidney disease assessed. The meta-analysis of Doppler ultrasound versus albuminuria shows insignificant statistical difference between high resistive index of ≥ 0.7 and albuminuria, with the resistive index being the favoured parameter on the forest plot, making Doppler ultrasound highly comparable with albuminuria for the detection of diabetic kidney disease. Again, there was a significant statistical difference between high intrarenal resistive index of ≥ 0.7 and low estimated glomerular filtration rate of < 60 mL/min/1.73 m², with the resistive index being the favoured parameter on the forest plot, making Doppler ultrasound a superior parameter compared with estimated glomerular filtration rate for early detection of diabetic kidney disease.

The Compatibility of the Treatment Modalities to the Recommendations of the Kidney Disease Outcomes Quality Initiative Guideline in Chronic Kidney Disease Patients with Diabetes

Background:

Diabetes mellitus (DM) and chronic kidney disease (CKD) are global growing health problems. Since DM is the major cause for CKD etiology, its development can be prevented with simple measures, like achievements of glycemic, lipid and blood pressure targets. This study aimed to evaluate whether the treatment goals for CKD patients with DM are achieved under the Kidney Disease Outcomes Quality Initiative (KDOQI) guideline.

Methods:

Overall, 160 CKD patients with DM were enrolled in the study performed in Usak, Turkey from Jan 2016 to Jan 2018. Compatibility with treatment goals defined in KDOQI 2012 guideline for HbA1c levels, hypertension and dyslipidemia were evaluated retrospectively.

Results:

Of 160 CKD patients [15 (9.4%) in stage 3a, 53 (33.1%) stage 3b, 51 (31.9%) stage 4 and 41 (25.6%) stage 5], 23 patients in stage 5 were on hemodialysis. Total compliance rate to hyperglycemia treatment was 94 of 160 patients (58.8%). Compatibility rates between different stages of CKD were similar. Hypertension was detected only in 134 patients. Sixty-six (49.3%) patients were compatible with the treatment goals, and as the CKD stages progressed, the rate of patients achieving hypertension treatment goals was declined (P=0.001). One-hundred and thirty-seven patients were not on hemodialysis and fifty-four (39.9%) of 137 patients achieved dyslipidemia goal. There was no difference between different stages of CKD.

Conclusion:

Under KDOQI 2012 guideline, treatment goal for hyperglycemia was better achieved than the treatment goals for hypertension and dyslipidemia. In CKD patients with DM the physicians should be also focused on the treatment of hypertension and dyslipidemia.

Effects of Probiotics on Diabetic Nephropathy: A Systematic Review

BACKGROUND

Diabetic Nephropathy is a frequent complication of diabetes mellitus due to functional and structural modifications in multiple kidney compartments. Probiotics have risen lately as a forthcoming therapeutic intervention but they have not been systematically evaluated in diabetic nephropathy so far. The aim of this systematic review was to evaluate randomized controlled trials and experimental studies assessing the effect of probiotic supplements on diabetic nephropathy.

METHODS

An extensive literature search was conducted through electronic databases (PubMed, Scopus, Cinahl and Medline) with the Medical Subject Headings and entry terms of "diabetic nephropathy", "diabetic renal disease" and "probiotics". The search yielded 116 results, 9 of which met the inclusion criteria for this systematic review.

RESULTS

Most of the microorganisms used in the studies belonged to the Lactobacillus and Bifidobacterium genus. The dosage ranged from 2×107 to 6×1010 CFU/ g. The form of the probiotics varied across the studies (capsules, sachets, soy milk, kefir and honey). The majority of the studies demonstrated the benefits of probiotic supplementation on the reduction of inflammation, oxidative stress and on the amelioration of renal function biomarkers in subjects with diabetic nephropathy. No major gastrointestinal adverse events were observed during the intervention time with probiotics.

CONCLUSION

Findings of this systematic review demonstrate the positive impact of probiotics on Diabetic Nephropathy without any major adverse events. Moreover, future larger randomized controlled trials with bigger samples and longer follow-up time are deemed necessary for further valid results on the effectiveness of probiotic supplementation on Diabetic Nephropathy.

Reducing NADPH Synthesis Counteracts Diabetic Nephropathy through Restoration of AMPK Activity in Type 1 Diabetic Rats

Diabetic nephropathy (DN) is a major complication of diabetes mellitus and a primary cause of end-stage renal failure. Clinical studies indicate that metabolic surgery improves DN; however, the mechanism remains unclear. Here, we report that Roux-en-Y Gastric Bypass (RYGB) surgery significantly blocked and reversed DN without affecting the insulin signaling pathway. This protective role of RYGB surgery is almost blocked by either inhibition or knockout of 5'AMP-activated protein kinase (AMPK) in podocytes. Furthermore, mRNA microarray data reveal that RYGB surgery obviously reduced the gene expression involved in nicotinamide adenine dinucleotide phosphate (NAPDH) synthesis. The expression of a key NADPH synthase, hexose-6-phosphate dehydrogenase (H6PD), was inhibited by the low plasma corticosterone level after surgery. In addition, blocking NAPDH synthesis by knocking down H6PD mimicked the beneficial role of RYGB surgery through activation of AMPK in podocytes. Therefore, this study demonstrates that reducing NADPH production is critical for renal AMPK activation in response to RYGB surgery.

Efficacy of tripterygium glycosides for diabetic nephropathy: a meta-analysis of randomized controlled trials

Backgrounds

Diabetic nephropathy (DN) is one of the most important clinical complications of diabetes mellitus (DM) and is the most common cause of end-stage renal disease. Currently, there is no highly effective medicine that can prevent, halt, or reverse the progressive course of DN. Initial clinical data showed that Tripterygium glycosides (TGs), a traditional Chinese medicine, can decrease proteinuria in patients with DN.

Objectives

The objective of the present study is to investigate the efficacy and safety of TGs for the treatment of DN through meta-analysis of randomized controlled trials (RCTs).

Methods

All RCTs of TGs for DN were collected from The China National Knowledge Infrastructure (CNKI), PubMed, Web of Science, Wanfang Data, Chinese Biomedical Literature Database (CBM), China Science and Technology Journal Database (VIP) by setting the study inclusion and elimination standards. Two reviewers evaluated the quality of the trials and extracted the data independently. RevMan 5.4 software was used for meta-analyses. The primary outcome was a change in 24-hours urinary total protein (24 h TUP).

Results

26 RCTs with 1824 participants were identified. Studies were assessed using the Cochrane risk of bias tool. The overall effects showed that TGs was compared with the controls, TGs showed significant effects in reducing 24 h TUP [WMD = -0.84, 95 % CI (-1.09, -0.59)], elevating serum albumin [WMD = 2.88, 95 % CI (1.87, 3.90)], and the total efficiency [OR = 4.08, 95 % CI (2.37, 7.04)]. This effect was consistent across the subgroups of period of intervention.

Conclusions

The present research showed that TGs was significantly associated with improvement of renal function in patients with DN. TGs offers a novel approach to the treatment of DN, more high-quality RCTs are needed for a better understanding of the role of TGs in DN therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02487-8.

Assessment of Simple Bedside Wound Characteristics for a Prediction Model for Diabetic Foot Ulcer Outcomes

BACKGROUND

Evidence-based learning systems built on prediction models can support wound care community nurses (WCCNs) during diabetic foot ulcer care sessions. Several prediction models in the area of diabetic foot ulcer healing have been developed, most built on cardiovascular measurement data. Two other data types are patient information (i.e. sex and hemoglobin A1c) and wound characteristics (i.e. wound area and wound duration); these data relate to the status of the diabetic foot ulcer and are easily accessible for WCCNs. The aim of the study was to assess simple bedside wound characteristics for a prediction model for diabetic foot ulcer outcomes.

METHOD

Twenty predictor variables were tested. A pattern prediction model was used to forecast whether a given diabetic foot ulcer would (i) increase in size (or not) or (ii) decrease in size. Sensitivity, specificity, and area under the curve (AUC) in a receiver-operating characteristics curve were calculated.

RESULTS

A total of 162 diabetic foot ulcers were included. In combination, the predictor variables necrosis, wound size, granulation, fibrin, dry skin, and age were most informative, in total an AUC of 0.77.

CONCLUSIONS

Wound characteristics have potential to predict wound outcome. Future research should investigate implementation of the prediction model in an evidence-based learning system.

Renal sinus fat volume in type 2 diabetes mellitus is associated with glycated hemoglobin and metabolic risk factors

AIMS

We aimed to compare renal sinus fat volume assessed by MRI between patients with type 2 diabetes and healthy volunteers, and investigate the association between renal sinus fat and metabolic traits.

METHODS

In this cross-sectional study, renal sinus fat and parenchyma volumes measured on abdominal MRI were compared between patients and controls using analysis of covariance. Associations of renal parameters with clinical characteristics were analyzed using linear regression analysis.

RESULTS

A total of 146 participants were enrolled, consisting of 95 type 2 diabetes patients (57.2±8.8years, 49.5% male) and 51 controls (54.0±9.2years, 43.1% male). Patients with diabetes demonstrated larger sinus fat volumes (15.4±7.5cm³ vs. 10.3±7.1cm³, p<0.001) and sinus fat-parenchyma ratio than controls. In the total population, renal sinus fat was positively associated with HbA1c, abdominal VAT, cholesterol and triglycerides, after adjustment for age, sex, ethnicity and type 2 diabetes. In type 2 diabetes patients, increased sinus fat volume was significantly associated with urinary albumin-to-creatinine ratio.

CONCLUSION

Renal sinus fat volume is positively associated with several metabolic risk factors including HbA1c level and urinary albumin-to-creatinine ratio in type 2 diabetes patients, indicating a potential role of renal sinus fat in the development of diabetic nephropathy. Future studies are needed to investigate whether sinus fat volume can serve as an early biomarker for diabetic nephropathy.

Baked cod consumption delayed the development of kidney and liver dysfunction and affected plasma amino acid concentrations, but did not affect blood pressure, blood glucose or liver triacylglycerol concentrations in obese fa/fa Zucker rats

Obesity is associated with changes in amino acid metabolism, and studies show that ingestion of fish proteins influence amino acid composition in plasma and urine, in addition to affecting risk factors for metabolic syndrome. Since the majority of fish proteins consumed by humans are as fish fillet, it is of interest to investigate if cod fillet intake affects amino acid composition and metabolic disorders. We hypothesized that a modified AIN-93G diet containing cod fillet would affect amino acid compositions in plasma and urine in obese rats, and also affect risk factors for metabolic syndrome when compared to rats fed a regular AIN-93G diet with casein as the protein source. Obese Zucker fa/fa rats, a rat model of metabolic syndrome, received diets containing 25% protein from lyophilized baked cod fillet and 75% protein from casein (Baked cod diet), or a Control diet with casein for four weeks. The Baked cod diet affected the amino acid composition in plasma, with e.g., lower glycine, histidine, homoarginine, homocysteine, methionine, proline and tyrosine concentrations, but did not affect amino acid concentrations in urine. The concentrations of markers for kidney and liver dysfunction were lower in the Baked cod group, however blood pressure development, fasting and postprandial glucose, and hepatic triacylglycerol concentrations were similar to the Control group. To conclude, substituting 25% of dietary protein with baked cod fillet affected concentrations of some amino acids in plasma and delayed development of kidney and liver dysfunction, but did not affect blood pressure, glucose concentration or fatty liver.

Non-invasive metabolic biomarkers for early diagnosis of diabetic nephropathy: Meta-analysis of profiling metabolomics studies

AIM

Diabetic nephropathy (DN) is one of the worst complications of diabetes. Despite a growing number of DN metabolite profiling studies, most studies are suffering from inconsistency in their findings. The main goal of this meta-analysis was to reach to a consensus panel of significantly dysregulated metabolites as potential biomarkers in DN.

DATA SYNTHESIS

To identify the significant dysregulated metabolites, meta-analysis was performed by "vote-counting rank" and "robust rank aggregation" strategies. Bioinformatics analyses were performed to identify the most affected genes and pathways. Among 44 selected studies consisting of 98 metabolite profiles, 17 metabolites (9 up-regulated and 8 down-regulated metabolites), were identified as significant ones by both the meta-analysis strategies (p-value<0.05 and OR>2 or <0.5) and selected as DN metabolite meta-signature. Furthermore, enrichment analyses confirmed the involvement of various effective biological pathways in DN pathogenesis, such as urea cycle, TCA cycle, glycolysis, and amino acid metabolisms. Finally, by performing a meta-analysis over existing time-course studies in DN, the results indicated that lactic acid, hippuric acid, allantoin (in urine), and glutamine (in blood), are the topmost non-invasive early diagnostic biomarkers.

CONCLUSION

The identified metabolites are potentially involved in diabetic nephropathy pathogenesis and could be considered as biomarkers or drug targets in the disease.

PROSPERO REGISTRATION NUMBER

CRD42020197697.

Diabetic Nephropathy: Challenges in Pathogenesis, Diagnosis, and Treatment

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide. Chronic hyperglycemia and high blood pressure are the main risk factors for the development of DN. In general, screening for microalbuminuria should be performed annually, starting 5 years after diagnosis in type 1 diabetes and at diagnosis and annually thereafter in type 2 diabetes. Standard therapy is blood glucose and blood pressure control using the renin-angiotensin system blockade, targeting A1c < 7%, and <130/80 mmHg. Regression of albuminuria remains an important therapeutic goal. However, there are problems in diagnosis and treatment of nonproteinuric DN (NP-DN), which does not follow the classic pattern of DN. In fact, the prevalence of DN continues to increase, and additional therapy is needed to prevent or ameliorate the condition. In addition to conventional therapies, vitamin D receptor activators, incretin-related drugs, and therapies that target inflammation may also be promising for the prevention of DN progression. This review focuses on the role of inflammation and oxidative stress in the pathogenesis of DN, approaches to diagnosis in classic and NP-DN, and current and emerging therapeutic interventions.

Clinical value of INSL3 in the diagnosis and development of diabetic nephropathy

Background

Insulin‐like factor 3 (INSL3) was stated to be an essential regulator in many diseases. This present study aimed to explore the underlying mechanisms of INSL3 in diabetic nephropathy (DN).

Methods

The serum samples were obtained from 121 DN patients, 67 T2DM patients, and 44 healthy controls. Twenty SD rats were used to establish the DN model in vivo. Quantitative PCR (qPCR) and Western blot were completed to analyze the INSL3 expression in cells, serum samples, and kidney of the rats. The structure of kidney was analyzed by HE staining. The diagnostic values of INSL3 in DN were determined by receiver operating characteristic (ROC) assay. Then, Spearman's correlation analysis was executed to verify the association between INSL3 and glomerular filtration rate (eGFR). Finally, the proliferation and apoptosis status of transfected cells were analyzed by MTT, flow cytometry, and Hoechst33258 staining assay.

Results

We found that INSL3 expression was up‐regulated in DN patients and SV40‐MES‐13 cells. Furthermore, the correlation analysis elucidated that INSL3 expression was negatively correlated with DN diagnosis golden criterion eGFR. INSL3 knockdown promoted the proliferation rate and inhibited the apoptosis rate of SV40‐MES‐13 cells after high‐glucose treatment. Finally, the INSL3 expression and fast blood glucose were up‐regulated in DN rats.

Conclusions

Collectively, this study demonstrated the clinical significance of INSL3 in diagnosing and developing DN.

Transcription factor 7-like 2 gene- smoking interaction on the risk of diabetic nephropathy in Chinese Han population

Objectives

To evaluate the relationship between transcription factor 7-like 2 (TCF7L2) gene polymorphism and diabetic nephropathy (DN) risk, as well as the effect of gene-environment interactions on DN risk in Chinese Han population.

Methods

The Hardy-Weinberg equilibrium (HWE) and the relationship between TCF7L2 gene single nucleotide polymorphism (SNPs) and DN susceptibility were evaluated by SNPStats. The interaction among four SNPs and environmental factors were tested by generalized multifactor dimensionality reduction (GMDR). The consistency of cross validation, accuracy of test balance and sign test were calculated to evaluate the interaction of each selection. The logistic regression was used to test the interaction between rs7903146 and current smoking by stratified analysis.

Results

Logistic regression analysis indicated that the DN risk of rs7903146-T allele carriers were obviously higher than that in CC genotype carriers (CT + TT versus CC), adjusted OR (95 %CI) = 1.64 (1.24–2.06). However, we also discovered that people with rs12255372, rs11196205 and rs290487 minor allele had non-significant difference risk of DN compared with people with major allele. The GMDR model found a significant two-locus model (p = 0.0100) including rs7903146 and current smoking, suggesting a potential gene–environment interaction between rs7903146 and current smoking. Compared with never smokers with rs7903146- CC genotype, current smokers with rs7903146- CT or TT genotype had the highest DN risk. After covariate adjustment, OR (95 %CI) was 2.15 (1.58–2.78).

Conclusions

We found a significant relationship of rs7903146-T alleles, and the interaction between rs7903146-T and current smoking with increased DN risk.

Relationship between the FTO Genotype and Early Chronic Kidney Disease in Type 2 Diabetes: The Mediating Role of Central Obesity, Hypertension, and High Albuminuria

INTRODUCTION

Single nucleotide polymorphisms (SNP) in the fat mass and obesity-associated (FTO) gene have been associated with type 2 diabetes (T2D) and its complications. The aim of the present research was to investigate which and how (directly or indirectly) clinical and metabolic variables mediate the association between fat mass and the FTO gene and early chronic kidney disease (CKD) in individuals with T2D.

METHODS

This cross-sectional study was conducted in a sample of 236 participants with T2D (53.4% women, mean age 60 ± 10 years). DNA samples were genotyped for the rs7204609 polymorphism (C/T) in the FTO gene. Clinical, anthropometric, and metabolic data were collected. Path analysis was used to evaluate the associations.

RESULTS

Of the sample, 78 individuals with T2D had CKD (33%). Presence of the risk allele (C) was higher among participants with CKD (21.8 vs. 10.8%; p = 0.023). This polymorphism was positively associated with higher waist circumference, which in turn was associated with higher glycated hemoglobin and higher blood pressure. A higher blood-pressure level was associated with higher urinary albumin excretion (UAE) and as expected, higher UAE was associated with CKD. Path analysis showed an indirect relationship between the FTO gene and early CKD, mediated by waist circumference, blood-pressure levels, and UAE.

CONCLUSIONS

These findings suggest that the C allele may contribute to genetic susceptibility to CKD in individuals with T2D through the presence of central obesity, hypertension, and high albuminuria.

Calycosin-loaded nanoliposomes as potential nanoplatforms for treatment of diabetic nephropathy through regulation of mitochondrial respiratory function

BACKGROUNDS

One of the most common complications in diabetic nephropathy is generation of high levels of ROS which can be regulated by herbal antioxidants. However, polyphenols like calycosin, the bioactive compound of Radix astragali suffer from low solubility and poor bioavailability.

METHODS

Therefore, in the present study, calycosin-loaded nanoliposomes were fabricated and characterized by TEM, DLS and FTIR techniques. Afterwards, the drug loading (DL) and entrapment efficiency (EE), drug release, solubility, stability, and pharmacodynamic assays were performed. Finally, the antinephropathic effects of calycosin-loaded-nanoliposomes on mitochondria of kidney cells were explored by MTT, ROS, MDA, mitochondrial respiratory function assays.

RESULTS

The result showed that the size, hydrodynamic radius, zeta potential, EE, and DL were, 80 nm, 133.99 ± 21.44 nm, - 20.53 ± 3.57, 88.37 ± 2.28%, and 7.48 ± 1.19%, respectively. The outcomes of in vitro release assay showed that calycosin-loaded nanoliposomes were significantly slow-release in dialysis media with pH 1.2, pH 6.9 and pH 7.4, at about 30 min, the dissolution of calycosin from nanoliposome became almost complete, and after 2 months, the calycosin-loaded nanoliposomes were still stable. Pharmacokinetic assay revealed that the AUC0-t of calycosin in calycosin-loaded nanoliposome group was 927.39 ± 124.91 μg/L*h, which was 2.26 times than that of the free calycosin group (**P < 0.01). Additionally, the MRT0-t and t1/2 of calycosin in the calycosin-loaded nanoliposome group were prolonged by 1.54 times and 1.33 times than that of free calycosin group, respectively (*P < 0.05). Finally, it was shown that calycosin-loaded nanoliposomes regulated the viability, ROS production, lipid peroxidation and function of mitochondria in kidney cells of diabetic rats as a model of diabetic nephropathy.

CONCLUSION

In conclusion it may be suggested that new therapies based on nano-formulated calycosin can restore mitochondrial function which can improve diabetic nephropathy.

Biomarker evidence for distal tubular damage but cortical sparing in hospitalized diabetic patients with acute kidney injury (AKI) while on SGLT2 inhibitors

Background

Inhibitors of sodium-glucose co-transporter-2 (SGLT2i) were found to improve renal outcome in diabetic patients in large prospective randomized trials. Yet, SGLT2i may acutely reduce kidney function through volume depletion, altered glomerular hemodynamics or intensified medullary hypoxia leading to acute tubular injury (ATI). The aim or this study was to prospectively assess the pathophysiology of acute kidney injury (AKI) in patients hospitalized while on SGLT2i, differing ATI from pre-renal causes using renal biomarkers.

Methods

Serum and urine Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Kidney Ischemia Molecule (KIM)-1, markers of distal and proximal tubular injury, respectively, were determined in 46 diabetic patients who were on SGLT2i upon hospitalization with an acute illness.

Results

Serum and urine NGAL, but not KIM-1, were significantly increased in 21 of the patients who presented with AKI upon admission, as compared with 25 patients that maintained kidney function. Both serum and urinary NGAL correlated with the degree of impaired renal function, which in many cases was likely the result of additional acute renal perturbations, such as sepsis.

Conclusions

Increased urinary and serum NGAL indicates that ATI, principally affecting distal tubular segments, may develop in some of the patients hospitalized with an acute illness and AKI while on SGLT2i. It is suggested that intensified medullary hypoxia by SGLT2i might be detrimental in this injury. By contrast, concomitantly unaltered KIM-1 might reflect improved cortical oxygenation by SGLT2i, and may explain an overall reduced risk of AKI with SGLT1i in large series. The independent potential of SGLT2i to inflict medullary hypoxic damage should be explored further.

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.

Epigenetic regulation of TXNIP-mediated oxidative stress and NLRP3 inflammasome activation contributes to SAHH inhibition-aggravated diabetic nephropathy

S-adenosylhomocysteine (SAH) is hydrolyzed by SAH hydrolase (SAHH) to homocysteine and adenosine. Increased plasma SAH levels were associated with disturbed renal function in patients with diabetes. However, the role and mechanism of SAHH in diabetic nephropathy is still unknown. In the present study, we found that inhibition of SAHH by using its inhibitor adenosine dialdehyde (ADA) accumulates intracellular or plasma SAH levels and increases high glucose-induced podocyte injury and aggravates STZ-induced diabetic nephropathy, which is associated with Nod-like receptor protein 3 (NLRP3) inflammasome activation. Inhibition or knockout of NLRP3 attenuates SAHH inhibition-aggravated podocyte injury and diabetic nephropathy. Additionally, SAHH inhibition increases thioredoxin-interacting protein (TXNIP)-mediated oxidative stress and NLRP3 inflammasome activation, but these effects were not observed in TXNIP knockout mice. Mechanistically, SAHH inhibition increased TXNIP by inhibiting histone methyltransferase enhancer of zeste homolog 2 (EZH2) and reduced trimethylation of histone H3 lysine 27 and its enrichment at promoter of early growth response 1 (EGR1). Moreover, EGR1 is activated and enriched at promoters of TXNIP by SAHH inhibition and is essential for SAHH inhibition-induced TXNIP expression. Inhibition of EGR1 protected against SAHH inhibition-induced NLRP3 inflammasome activation and oxidative stress and diabetic nephropathy. Finally, the harmful effects of SAHH inhibition on inflammation and oxidative stress and diabetic nephropathy were also observed in heterozygote SAHH knockout mice. These findings suggest that EZH2/EGR1/TXNIP/NLRP3 signaling cascade contributes to SAHH inhibition-aggravated diabetic nephropathy. Our study firstly provides a novel insight into the role and mechanism of SAHH inhibition in diabetic nephropathy.

•

SAHH inhibition accumulates SAH levels and aggravates podocyte injury and diabetic nephropathy.

•

SAHH inhibition induces TXNIP-mediated oxidative stress and NLRP3 inflammasome activation.

•

SAHH inhibition increases TXNIP by inhibiting EZH2 and reducing H3K27me3 and its enrichment at promoter of EGR1.

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EGR1 is required for SAHH inhibition-induced TXNIP and NLRP3 inflammasome activation and diabetic nephropathy.

Manifestation of rs1888747 polymorphisms in the FRMD3 gene in diabetic kidney disease and diabetic retinopathy in type 2 diabetes patients

Background

FRMD3 polymorphisms has suggested that they could be an alternative test to differentiate diabetic nephropathy (DN) from nondiabetic renal disease (NDRD) in type 2 diabetes mellitus (DM) patients. This study was performed to investigate the relationship between the FRMD3 gene and clinical characteristics of DN.

Methods

Patients who already had renal pathologic results were tested for FRMD3 polymorphisms. The subjects were classified into three groups; DN with diabetic retinopathy (DR), DN without DR, and DM with NDRD. FRMD3 polymorphisms were analyzed in each group.

Results

The prevalence of GG, CG, and CC was 44.4%, 42.2%, and 13.3% respectively. There was no significant difference in clinical parameters, which consisted of disease duration, proteinuria, and complications in DN with or without DR and DM with NDRD. The G allele was mainly found in DN with DR patients (50.8%) whereas the C allele was found in DM with NDRD patients (43.5%) (p = 0.02). There was a significant association between the CC genotype in NDRD when compared to GG (p = 0.001). In addition, the C allele was 2.10-fold more often associated with NDRD than the G allele (p = 0.03). The CC genotype was correlated with risk for NDRD than the GG and GC genotypes, with odds ratios of 6.89 and 4.91, respectively (p = 0.02).

Conclusion

C allele presentation, especially homozygous CC, was associated with NDRD pathology in patients with overt proteinuria. Hence, kidney biopsy is suggested in those with the C allele or homozygous CC genotype, regardless of retinopathy manifestations.

Deficiency of Mitochondrial Glycerol 3-Phosphate Dehydrogenase Exacerbates Podocyte Injury and the Progression of Diabetic Kidney Disease

Mitochondrial function is essential for bioenergetics, metabolism, and signaling and is compromised in diseases such as proteinuric kidney diseases, contributing to the global burden of kidney failure, cardiovascular morbidity, and death. The key cell type that prevents proteinuria is the terminally differentiated glomerular podocyte. In this study, we characterized the importance of mitochondrial glycerol 3-phosphate dehydrogenase (mGPDH), located on the inner mitochondrial membrane, in regulating podocyte function and glomerular disease. Specifically, podocyte-dominated mGPDH expression was downregulated in the glomeruli of patients and mice with diabetic kidney disease and adriamycin nephropathy. Podocyte-specific depletion of mGPDH in mice exacerbated diabetes- or adriamycin-induced proteinuria, podocyte injury, and glomerular pathology. RNA sequencing revealed that mGPDH regulated the receptor for the advanced glycation end product (RAGE) signaling pathway, and inhibition of RAGE or its ligand, S100A10, protected against the impaired mitochondrial bioenergetics and increased reactive oxygen species generation caused by mGPDH knockdown in cultured podocytes. Moreover, RAGE deletion in podocytes attenuated nephropathy progression in mGPDH-deficient diabetic mice. Rescue of podocyte mGPDH expression in mice with established glomerular injury significantly improved their renal function. In summary, our study proposes that activation of mGPDH induces mitochondrial biogenesis and reinforces mitochondrial function, which may provide a potential therapeutic target for preventing podocyte injury and proteinuria in diabetic kidney disease.

Insulin protects against type 1 diabetes mellitus-induced aortopathy associated with the inhibition of biomarkers of vascular injury in rats

BACKGROUND

We sought to investigate the protective effect of insulin against type 1 diabetes mellitus (T1DM)-induced aortic injury (aortopathy) associated with the inhibition of biomarkers of vascular injury.

MATERIAL AND METHODS

T1DM was induced in rats by streptozotocin (STZ) (65 mg/kg), and the protection group started insulin treatment 2 days post diabetic induction and continued until being sacrificed at week 8.

RESULTS

Aortopathy was developed in the diabetic rats as demonstrated by profound alterations to the aorta ultrastructure, which was substantially protected by insulin. In addition, insulin significantly inhibited diabetes-induced dyslipidaemia, soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1), oxidative stress, and inflammation. However, blood levels of these biomarkers in the insulin-treated group were still significant (p < .05) compared with the control group, whereas insulin treatment returned blood glucose and triglyceride to control levels.

CONCLUSIONS

We demonstrate effective protection by insulin against T1DM-induced aortopathy in rats, which is associated with the inhibition of vascular injury biomarkers.

Acetate ameliorates nephrotoxicity in streptozotocin-nicotinamide-induced diabetic rats: Involvement of xanthine oxidase activity

Impaired renal function is a common complication of diabetes mellitus (DM) that often degenerates to cardiovascular disease, contributing to high morbidity and reduced survival worldwide. Short chain fatty acids (SCFAs), including acetate has shown potential benefits in glycemic or metabolic regulation but its effect on diabetes-associated renal toxicity/impairment is not clear. Herein, we investigated the hypothesis that acetate would ameliorate renal toxicity, accompanying DM, possibly by suppression of xanthine oxidase (XO) activity. Adult male Wistar rats (230-260 g) were allotted into groups (n = 6/group) namely: control (vehicle; po), sodium acetate (NaAc)-treated (200 mg/kg), diabetic with or without NaAc groups. DM was induced by intraperitoneal injection of streptozotocin 65 mg/kg after a dose of nicotinamide (110 mg/kg). Diabetic animals showed increased fasting glucose and insulin, renal triglyceride, total cholesterol, atherogenic lipid, malondialdehyde, XO, tissue necrosis factor-α, uric acid, interleukin-6, aspartate transaminase/alanine aminotransferase ratio, gamma-glutamyl transferase and decreased glutathione and nitric oxide concentration. The renal tissue was characterized with disrupted tissue architecture, enlarged Bowman's space, congested glomeruli and adherence of abnormal segments of tuft to Bowman's capsule with consequent elevated serum creatinine and urea concentration. However, these alterations were attenuated by NaAc. The study demonstrates that acetate ameliorates diabetes-induced nephrotoxicity, which is associated with suppressed XO and its accompanied pro-inflammatory mediators. Therefore, SCFAs, acetate would be a promising dietary-derived therapeutic agent for the prevention and management of diabetes-associated renal disturbances.

Association between PTX3 and PVT1 genetic polymorphisms and the risk of diabetic kidney disease in type 2 diabetic patients

Background

Very few studies have investigated the role of PTX3 and PVT1 genetic polymorphisms and their association in the progression of diabetic kidney diseases. Diabetic kidney disease (DKD) is a prominent reason of end-stage renal disease and also known to be involved in the high mortality rate of cardiovascular diseases. The current study has examined the role of PTX3 and PVT1 genetic polymorphisms in the development of diabetic kidney disease in type 2 diabetic patients.

Results

A significant difference between the genotypes and alleles of the rs2305619 polymorphism was observed in the diabetic patients with DKD when compared with the control group. The frequency of GG genotype was observed to be high in diabetic patients with DKD when compared to the other two groups. This specified that diabetic patients with GG genotype are at an increased risk to develop DKD. However, PVT1 (G/A) polymorphism did not show any association in the allele and genotypic frequencies with DKD when compared with T2DM and controls.

Conclusion

Our results propose a major influence of GG genotype of rs2305619 polymorphism to be significantly linked with an increased risk of DKD in type 2 diabetic patients.

The Emerging Role of HDACs: Pathology and Therapeutic Targets in Diabetes Mellitus

Diabetes mellitus (DM) is one of the principal manifestations of metabolic syndrome and its prevalence with modern lifestyle is increasing incessantly. Chronic hyperglycemia can induce several vascular complications that were referred to be the major cause of morbidity and mortality in DM. Although several therapeutic targets have been identified and accessed clinically, the imminent risk of DM and its prevalence are still ascending. Substantial pieces of evidence revealed that histone deacetylase (HDAC) isoforms can regulate various molecular activities in DM via epigenetic and post-translational regulation of several transcription factors. To date, 18 HDAC isoforms have been identified in mammals that were categorized into four different classes. Classes I, II, and IV are regarded as classical HDACs, which operate through a Zn-based mechanism. In contrast, class III HDACs or Sirtuins depend on nicotinamide adenine dinucleotide (NAD+) for their molecular activity. Functionally, most of the HDAC isoforms can regulate β cell fate, insulin release, insulin expression and signaling, and glucose metabolism. Moreover, the roles of HDAC members have been implicated in the regulation of oxidative stress, inflammation, apoptosis, fibrosis, and other pathological events, which substantially contribute to diabetes-related vascular dysfunctions. Therefore, HDACs could serve as the potential therapeutic target in DM towards developing novel intervention strategies. This review sheds light on the emerging role of HDACs/isoforms in diabetic pathophysiology and emphasized the scope of their targeting in DM for constituting novel interventional strategies for metabolic disorders/complications.

Asprosin, a novel pleiotropic adipokine implicated in fasting and obesity-related cardio-metabolic disease: Comprehensive review of preclinical and clinical evidence

White adipose tissue is a dynamic endocrine organ that releases an array of adipokines, which play a key role in regulating metabolic homeostasis and multiple other physiological processes. An altered adipokine secretion profile from adipose tissue depots frequently characterizes obesity and related cardio-metabolic diseases. Asprosin is a recently discovered adipokine that is released in response to fasting. Following secretion, asprosin acts - via an olfactory G-protein coupled receptor and potentially via other unknown receptor(s) - on hepatocytes and agouti-related peptide-expressing neurons in the central nervous system to stimulate glucose secretion and promote appetite, respectively. A growing body of both in vitro and in vivo studies have shown asprosin to exert a number of effects on different metabolic tissues. Indeed, asprosin can attenuate insulin signalling and promote insulin resistance in skeletal muscle by increasing inflammation and endoplasmic reticulum stress. Interestingly, asprosin may also play a protective role in cardiomyocytes that are exposed to hypoxic conditions. Moreover, clinical studies have reported elevated circulating asprosin levels in obesity, type 2 diabetes and other obesity-related cardio-metabolic diseases, with significant associations to clinically relevant parameters. Understanding the spectrum of the effects of this novel adipokine is essential in order to determine its physiologic role and its significance as a potential therapeutic target and/or a biomarker of cardio-metabolic disease. The present review offers a comprehensive overview of the published literature on asprosin, including both clinical and preclinical studies, focusing on its role in metabolism and cardio-metabolic disease.

Both Specific Endothelial and Proximal Tubular Adam17 Deletion Protect against Diabetic Nephropathy

ADAM17 is a disintegrin and metalloproteinase capable of cleaving the ectodomains of a diverse variety of molecules including TNF-α, TGF-α, L-selectin, and ACE2. We have previously demonstrated that renal ADAM17 is upregulated in diabetic mice. The role of endothelial (eAdam17) and proximal tubular (tAdam17) Adam17 deletion in renal histology, modulation of the renin angiotensin system (RAS), renal inflammation, and fibrosis was studied in a mouse model of type 1 Diabetes Mellitus. Moreover, the effect of Adam17 deletion in an in vitro 3D cell culture from human proximal tubular cells under high glucose conditions was evaluated. eAdam17 deletion attenuates renal fibrosis and inflammation, whereas tAdam17 deletion decreases podocyte loss, attenuates the RAS, and decreases macrophage infiltration, α-SMA and collagen accumulation. The 3D in vitro cell culture reinforced the findings obtained in tAdam17KO mice with decreased fibrosis in the Adam17 knockout spheroids. In conclusion, Adam17 deletion either in the endothelial or the tubular cells mitigates kidney injury in the diabetic mice by targeting different pathways. The manipulation of Adam17 should be considered as a therapeutic strategy for treating DN.

Roles of Gut Microbial Metabolites in Diabetic Kidney Disease

Diabetes is a highly prevalent metabolic disease that has emerged as a global challenge due to its increasing prevalence and lack of sustainable treatment. Diabetic kidney disease (DKD), which is one of the most frequent and severe microvascular complications of diabetes, is difficult to treat with contemporary glucose-lowering medications. The gut microbiota plays an important role in human health and disease, and its metabolites have both beneficial and harmful effects on vital physiological processes. In this review, we summarize the current findings regarding the role of gut microbial metabolites in the development and progression of DKD, which will help us better understand the possible mechanisms of DKD and explore potential therapeutic approaches for DKD.

EndMT Regulation by Small RNAs in Diabetes-Associated Fibrotic Conditions: Potential Link With Oxidative Stress

Diabetes-associated complications, such as retinopathy, nephropathy, cardiomyopathy, and atherosclerosis, the main consequences of long-term hyperglycemia, often lead to organ dysfunction, disability, and increased mortality. A common denominator of these complications is the myofibroblast-driven excessive deposition of extracellular matrix proteins. Although fibroblast appears to be the primary source of myofibroblasts, other cells, including endothelial cells, can generate myofibroblasts through a process known as endothelial to mesenchymal transition (EndMT). During EndMT, endothelial cells lose their typical phenotype to acquire mesenchymal features, characterized by the development of invasive and migratory abilities as well as the expression of typical mesenchymal products such as α-smooth muscle actin and type I collagen. EndMT is involved in many chronic and fibrotic diseases and appears to be regulated by complex molecular mechanisms and different signaling pathways. Recent evidence suggests that small RNAs, in particular microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are crucial mediators of EndMT. Furthermore, EndMT and miRNAs are both affected by oxidative stress, another key player in the pathophysiology of diabetic fibrotic complications. In this review, we provide an overview of the primary redox signals underpinning the diabetic-associated fibrotic process. Then, we discuss the current knowledge on the role of small RNAs in the regulation of EndMT in diabetic retinopathy, nephropathy, cardiomyopathy, and atherosclerosis and highlight potential links between oxidative stress and the dyad small RNAs-EndMT in driving these pathological states.

Factors Influencing Renal Parenchymal Stiffiness in Patients with Diabetic Nephropathy

Objective

Glomerulosclerosis and tubulointerstitial fibrosis are associated with lower renal parenchymal resilience. The purpose of this study is to determine the factors influencing renal resilience in patients with diabetic nephropathy (DN).

Methods

We recruited 56 healthy volunteers and 187 patients with DN. All the participants were evaluated using shear-wave elastography (SWE), and the size of their kidneys and Young's modulus values for the parenchyma were recorded. A total of 187 patients with DN are allocated to three groups according to their urinary albumin-to-creatinine ratio: normoalbuminuric (<30 mg/g creatinine), microalbuminuric (30-300 mg/g), and macroalbuminuric (≥300 mg/g) groups. Renal resilience is compared between the stages of diabetic nephropathy and the healthy control group, and the factors affecting the stiffiness of the renal parenchyma in DN are analyzed.

Results

The renal parenchyma is harder in participants with DN than in healthy participants (P < 0.001), and the stiffiness increases with the progression of the disease (P < 0.001). Multivariate logistic regression analysis shows that disease stage (β = 0.789, P < 0.001), duration of diabetes (β = 0.028, P < 0.001), and serum creatinine (SCr) concentration (β = 0.001, p < 0.001) influence the stiffiness of the renal parenchyma.

Conclusion

We show that SWE can be used to measure changes in the stiffiness of the renal parenchyma in patients with DN. Furthermore, Young's modulus of the renal parenchyma is related to the duration of diabetes, urinary albumin excretion, and SCr concentration. Thus, SWE can be used to objectively and non-invasively stage DN.

Targeted metabolomics as a tool for the diagnosis of kidney disease in Type II diabetes mellitus

Background: Diabetic kidney disease (DKD) is an increasing health problem and an extra burden to health services. The study of characteristic metabolic alterations of DKD is crucial for a better understanding of pathogenesis to identify new potential biomarkers and drug targets. We hypothesized that metabolic profiling of amino acids, acylcarnitines, and organic acids are useful new biomarkers for the diagnosis of the early stages of DKDMethods: The hypothesis was testing in a case-control study of 232 patients with type 2 diabetes mellitus and 150 healthy controls. Patients were classified according to urinary albumin and estimated glomerular filtration rate (eGFR) into 100 with normoalbuminuria and 132 with microalbuminuria group. Eighteen AcylCNs and 17 amino acids were measured in the blood by tandem mass spectrometry while 17 urinary organic acids were quantitatively measured by gas chromatography - mass spectrometry.Results: Regression analysis found that dodecanoylcarnitines C12 (effect size 2.03 [95%CI 1.73-2.32]), triglylcarnitine C5:1 (2.01 [1.70-2.30]), and isovalerylcarnitine C5 (1.78 [1.48-2.07]) were stronger predictors of albumin/creatinine ratio than HbA1c (1.50 [1.20-1.78]) and hence they could serve as potential biomarkers for the diagnosis of the early stages of DKD.Conclusions: Targeted metabolic profiling offers a new, non-invasive approach for detecting biomarkers for the early diagnosis of DKD suggesting new pathogenetic phases that might be new targets for treatment.

Hyperoside ameliorates diabetic nephropathy induced by STZ via targeting the miR-499-5p/APC axis

Diabetic nephropathy is a serious complication of diabetes. Hyperoside has been widely reported to ameliorate diabetes-associated disease. The current study is designed to explore the mechanism of hyperoside in diabetic nephropathy. In the present study, high glucose was used to treat podocytes. Diabetic nephropathy mice models were established by high-fat feeding followed by multiple low dose injections of streptozocin. Western blot analysis was conducted for detection of extracellular matrix accumulation, inflammatory response and cell apoptosis. We found out that hyperoside improved high glucose-induced cell injury. Additionally, hyperoside prevented mice with diabetic nephropathy from diabetic symptoms and renal dysfunction. Mechanistically, hyperoside inhibited the mRNA and protein expression of APC. MiR-499-5p was found to be an upstream negative mediator of APC, and hyperoside induced the upregulation of miR-499-5p. MiR-499-5p bound with the 3' untranslated region of APC to inhibit its expression. Finally, rescue assays revealed that the suppressive effects of miR-499-5p overexpression on renal dysfunction were rescued by upregulation of APC in mice with diabetic nephropathy. In conclusion, these findings indicated that hyperoside ameliorates diabetic nephropathy via targeting the miR-499-5p/APC axis, suggesting that hyperoside may offer a potential tactic for diabetic nephropathy treatment.

Increased lipoxygenase and decreased cytochrome P450s metabolites correlated with the incidence of diabetic nephropathy: Potential role of eicosanoids from metabolomics in type 2 diabetic patients

Diabetic nephropathy (DN) is the major cause of chronic kidney disease and end-stage renal disease. Previous studies have demonstrated that long-chain omega-3 polyunsaturated fatty acids (PUFAs) might have therapeutic potential in reducing proteinuria in DN. However, the local level of eicosanoids derived from PUFAs in the plasma of DN patients remains unclear. This work aims to study the eicosanoid profile difference in plasma of DN patients and type 2 diabetes (T2D) without DN. A total of 27 T2D patients with similar diabetic duration were recruited and divided into T2D+DN group and T2D+NDN (non-DN) group based on urinary albumin excretion (UAE) detection. Using LC-MS/MS-based metabolomics, DN patients showed increased level of lipoxygenase (LOX) metabolites (5-HETE and LTB4) and decreased levels of eicosanoids derived according to the cytochrome P450s (CYP450) metabolic pathway (5,6-DHET; 14,15-DHET and 9,10-diHOME). Receiver operating characteristics and logistic regression analysis revealed increased level LOX metabolites and decreased level of CYP450 metabolites were significantly correlated with the incidence of DN in T2D patients. LOX and CYP450 metabolites correlated with DN incidence in T2D patients, which might be treatment targets for DN in T2D patients.