Glucose and Blood Pressure-Dependent Pathways-The Progression of Diabetic Kidney Disease

Traditional Chinese medicine improved diabetic kidney disease through targeting gut microbiota

CONTEXT

Diabetic kidney disease (DKD) affects nearly 40% of diabetic patients, often leading to end-stage renal disease that requires renal replacement therapies, such as dialysis and transplantation. The gut microbiota, an integral aspect of human evolution, plays a crucial role in this condition. Traditional Chinese medicine (TCM) has shown promising outcomes in ameliorating DKD by addressing the gut microbiota.

OBJECTIVE

This review elucidates the modifications in gut microbiota observed in DKD and explores the impact of TCM interventions on correcting microbial dysregulation.

METHODS

We searched relevant articles from databases including Web of Science, PubMed, ScienceDirect, Wiley, and Springer Nature. The following keywords were used: diabetic kidney disease, diabetic nephropathy, gut microbiota, natural product, TCM, Chinese herbal medicine, and Chinese medicinal herbs. Rigorous criteria were applied to identify high-quality studies on TCM interventions against DKD.

RESULTS

Dysregulation of the gut microbiota, including Lactobacillus, Streptococcus, and Clostridium, has been observed in individuals with DKD. Key indicators of microbial dysregulation include increased uremic solutes and decreased short-chain fatty acids. Various TCM therapies, such as formulas, tablets, granules, capsules, and decoctions, exhibit unique advantages in regulating the disordered microbiota to treat DKD.

CONCLUSION

This review highlights the importance of targeting the gut-kidney axis to regulate microbial disorders, their metabolites, and associated signaling pathways in DKD. The Qing-Re-Xiao-Zheng formula, the Shenyan Kangfu tablet, the Huangkui capsule, and the Bekhogainsam decoction are potential candidates to address the gut-kidney axis. TCM interventions offer a significant therapeutic approach by targeting microbial dysregulation in patients with DKD.

Association between dietary fiber intake and diabetic nephropathy among adult diabetes mellitus in the United States: A cross-sectional study

Objective

There has been some evidence that dietary fiber may be associated with diabetic nephropathy (DN), but the relationship is still unclear. The purpose of this study was to examine the association between dietary fiber intake and DN.

Methods

This cross-sectional study used National Health and Nutrition Examination Survey (NHANES) data collected between 2007 and 2020. Weighted multivariate logistic regression was used to examine the relation between dietary fiber intake and DN. In addition, fitted smoothed curves were used to explore potential non-linear relationships. If non-linearity was observed, inflection points were further calculated by a recursive algorithm.

Results

The study finally included 5964 subjects ≥20 years of age. The mean age was 60.8 ± 13.4 years with males (52.4 %), and non-Hispanic Whites (62.4 %), and the weighted prevalence of DN was 36.7 %. Dietary fiber was negatively associated with the risk of DN after controlling for all confounding variables (OR = 0.89, 95%CI: 0.80, 0.99). Smoothed curve fit plots of the dose relationship showed that dietary fiber intake was linearly related to DN, whereas males (inflection point of 8.0 g/d) and non-Hispanic Blacks (inflection point of 14.9 g/d) followed a non-linear inverted U-shaped curve relationship. In United States adults aged 20 and older, dietary fiber intake may be associated with a reduced risk of DN.

Conclusion

Appropriate increases in dietary fiber intake may offer potential benefits for DN. In conclusion, it appears that increasing dietary fiber intake may be one of the most effective strategies for the prevention and management of DN.

Gene Expression Analysis in T2DM and Its Associated Microvascular Diabetic Complications: Focus on Risk Factor and RAAS Pathway

Prolonged hyperglycemic conditions in type 2 diabetes mellitus (T2DM) cause pathological and functional damage to many organs and tissues, including the kidneys, retina, skin, and neuronal tissues, resulting in the development of microvascular diabetic complications. The altered renin angiotensin aldosterone system (RAAS) pathway has been reported to play an important role in the development of insulin resistance in T2DM and associated complications. The current study was carried out to evaluate the association of risk factors and altered expression of RAAS genes in T2DM patients without complications and T2DM patients with complications (retinopathy, nephropathy, and neuropathy). Four hundred and twenty subjects including 140 healthy controls, 140 T2DM patients with diabetic complications, and 140 T2DM patients without diabetic complications were included in the study. Risk factors associated with the development of T2DM and diabetic complications were evaluated. Further, expression analysis of RAAS genes (AGT, ACE, ACE2, and AGT1R) was carried out using qRTPCR in healthy controls, T2DM patients with complications, and T2DM patients without complications. Various risk factors like urban background, higher BMI, alcoholism, smoking, and family history of diabetes among others were found to be associated with the development of T2DM as well as diabetic complications. The expression level of AGT, ACE, and AGT1R was found to be upregulated whereas ACE2 was found to be downregulated in T2DM patients with complications and T2DM patients without complications as compared to controls. Altered expression of the studied genes of RAAS pathway is associated with the development of microvascular diabetic complications.

The molecular mechanism of "Dahuang-Shengjiang-Banxia decoction" in the treatment of diabetic kidney disease was verified based on network pharmacology and molecular docking

Background

Explore the molecular mechanism of Dahuang-Shengjiang-Banxia Decoction (DSBD) in the treatment of diabetic kidney disease (DKD), using network pharmacology and molecular docking technology.

Method

The effective ingredients and targets of the DSBD were taken from the TCMSP database, while the disease targets were obtained via GeneCards, OMIM, DrugBank, TTD, and DisGeNET. Cytoscape 3.9.1 was used to create a drug-ingredient-target network diagram. STRING databases are also used to analyze the Protein-Protein Interaction (PPI) network of intersecting targets. The core targets was obtained by the intersection of the differential genes screened from the intersection target and GEO, and the core targets was enriched by Gene ontology (GO), Kyoto gene and genome (KEGG), and Gene Set Enrichment Analysis (GSEA). CIBERSORTx was used for immunoinfiltration analysis, and then the core targets was analyzed by Nephroseq V5 and KIT for clinical correlation analysis and single-cell sequencing. Lastly, AutoDock Vina was used for molecular docking of both the core targets and the top active elements.

Results

A total of 177 DSBD and 2906 DKD targets were screened. Six core targets were identified by screening, which were IL1B, MMP9, EGF, VEGFA, HIF1A, and PTGS2. The top 6 active ingredients are 6-gingerol, baicalin, oleic acid, β-sitosterol, linolenic acid, and aloe emodin. The core targets has good docking activity with the active ingredient.

Conclusion

DSBD may exert its therapeutic effect on DKD through multicomponent, multipath, and multi-target analyses. It is possible that VEGFA is a key target in therapy, and that the VEGF/PI3K/AKT signaling pathway plays a key role in therapy.

Podocyte injury of diabetic nephropathy: Novel mechanism discovery and therapeutic prospects

Diabetic nephropathy (DN) is a severe complication of diabetes mellitus, posing significant challenges in terms of early prevention, clinical diagnosis, and treatment. Consequently, it has emerged as a major contributor to end-stage renal disease. The glomerular filtration barrier, composed of podocytes, endothelial cells, and the glomerular basement membrane, plays a vital role in maintaining renal function. Disruptions in podocyte function, including hypertrophy, shedding, reduced density, and apoptosis, can impair the integrity of the glomerular filtration barrier, resulting in elevated proteinuria, abnormal glomerular filtration rate, and increased creatinine levels. Hence, recent research has increasingly focused on the role of podocyte injury in DN, with a growing emphasis on exploring therapeutic interventions targeting podocyte injury. Studies have revealed that factors such as lipotoxicity, hemodynamic abnormalities, oxidative stress, mitochondrial dysfunction, and impaired autophagy can contribute to podocyte injury. This review aims to summarize the underlying mechanisms of podocyte injury in DN and provide an overview of the current research status regarding experimental drugs targeting podocyte injury in DN. The findings presented herein may offer potential therapeutic targets and strategies for the management of DN associated with podocyte injury.

Glomerular filtration rate in patients with type 2 diabetes mellitus: is serum isthmin-1 level a possible link?

INTRODUCTION

Isthmin-1 (Ism-1) is a novel adipokine. However, little is known regarding the association between Ism-1 and type 2 diabetes mellitus (T2DM). This study aimed to investigate the relationship between serum Ism-1 levels and glomerular filtration rate (GFR) in patients with T2DM.

RESEARCH DESIGN AND METHODS

A total of 209 patients with T2DM were recruited into this retrospective study. Clinical data were collected. Fasting blood samples were collected for serum Ism-1 testing using ELISA kits. Based on the estimated glomerular filtration rate (eGFR), participants were divided into the normal eGFR group (n=167) and the decreased eGFR group (n=42). The relationship between Ism-1 and eGFR was assessed using linear and binary logistic regression analyses. Receiver operating characteristic (ROC) curve analysis was employed to examine the predictive efficacy of Ism-1 for distinguishing patients with eGFR <60 mL/min/1.73 m2.

RESULTS

Compared with patients with normal eGFR, serum Ism-1 levels were increased in patients with decreased eGFR (p<0.001). Serum Ism-1 levels were negatively correlated with eGFR in patients with T2DM even after multiple adjustments (p<0.001). For each 0.1 ng/mL increment of Ism-1, the odds of having an eGFR <60 mL/min/1.73 m2 increased by 54.5% (OR=1.545; p<0.001) in patients with T2DM. ROC analysis showed that higher serum Ism-1 levels (>1.297 ng/mL) had predictive efficacy in patients with eGFR <60 mL/min/1.73 m2, with an area under the curve of 0.908.

CONCLUSIONS

Serum Ism-1 levels were inversely associated with eGFR, and high Ism-1 levels may be used as a potential biomarker for predicting kidney function impairment in patients with T2DM.

Dapagliflozin ameliorates diabetic renal injury through suppressing the self-perpetuating cycle of inflammation mediated by HMGB1 feedback signaling in the kidney

Dapagliflozin, the Sodium-glucose cotransporter 2 (SGLT2) inhibitor class of glucose-lowering agents, has shown the significantly nephroprotective effects to reduce the risk of kidney failure in diabetes. However, the underlying mechanisms are incompletely understood to explain the beneficial effects of dapagliflozin on kidney function. Here, we demonstrated that the administered of dapagliflozin for 12 weeks improved the proteinuria, histomorphology damage, oxidative stress, and macrophage infiltrations in the kidney of streptozotocin (STZ)-induced diabetic mice. Meanwhile, dapagliflozin attenuated the renal inflammation and fibrosis by reducing the pro-inflammatory factors interleukin-6 (IL-6), IL-1β, and tumor necrosis factor α (TNF-α) and anti-fiber factor fibronectin (FN) and elevating the anti-inflammatory factor IL-10. Our data revealed that dapagliflozin exerted anti-inflammatory effects by inhibiting the activation of high mobility group box 1 (HMGB1)/TLR2/4/NF-κB signaling pathway. Consistently, we found that dapagliflozin suppressed the expression of HMGB1 and downstream TLR2/4/NF-κB signaling proteins in the human proximal tubular (HK-2) stimulated by high glucose and lipids or HMGB1 and RAW264.7 cells stimulated by IL-1β, respectively. Further experiments were performed in the indirect co-culture model of RAW264.7 and HK-2 cells induced by high glucose and lipids. The results again confirmed the effects of dapagliflozin on alleviating inflammatory response and regulating the proportions of M1/M2 macrophage. It is indicated that the feedback signaling of HMGB1 between the tubules and macrophage involves in the persistence of the inflammation. These data demonstrate that dapagliflozin suppress the self-perpetuating inflammation by blocking the feedback loop of HMGB1 in the kidney, which contribute to ameliorate the renal injury in diabetes.

Regulation of Renin Expression by Β1-Integrin in As4.1 Juxtaglomerular Line Cells

(1) Background: Renal dysfunction and hypertension are mutually aggravating factors; however, the details of their interaction remain unclear. In a study using renal tissue from diabetic rats, we found that β1-integrin, a cell-substrate adhesion molecule, is specifically phosphorylated in juxtaglomerular cells that secrete renin, a blood pressure regulator. (2) Methods: A mouse juxtaglomerular cell line (As4.1 cells) was used for the following experiments: drug-induced promotion of β1-integrin phosphorylation/dephosphorylation; knockdown of β1-integrin and the cell adhesion molecule connexin-40 (a candidate for the main body of baroreceptor); and pressurization to atmospheric pressure + 100 mmHg. culture in hypotonic liquid medium. The expression of renin under these conditions was measured by qRT-PCR. (3) Results: Phosphorylation of β1-integrin suppressed the expression of renin, while dephosphorylation conversely promoted it. β1-integrin and connexin-40 knockdown both promoted the expression of renin. Pneumatic pressurization and hypotonic medium culture both decreased the expression of renin, which was restored by the knockdown of β1-integrin. (4) Conclusions: β1-integrin plays an inhibitory role in the regulation of the expression of renin, which may be controlled by phosphorylation and dephosphorylation. It is hypothesized that β1-integrin and other adhesion factors regulate the expression of renin by altering the sensitivity of baroreceptors on the plasma membrane.

Prediction models for risk of diabetic kidney disease in Chinese patients with type 2 diabetes mellitus

BACKGROUND

Diabetic kidney disease (DKD) is a common and serious complication in patients with diabetic mellitus (DM), the risk of cardiovascular events and all-cause mortality also increases in DKD patients. This study aimed to detect the influencing factors of DKD in type 2 DM (T2DM) patients, and construct DKD prediction models and nomogram for clinical decision-making.

METHODS

A total of 14,628 patients with T2DM were included. These patients were divided into pre-DKD and non-DKD groups, depending on the occurrence of DKD during a 3-year follow-up from first clinic attendance. The influencing indicators of DKD were analyzed, the prediction models were established by multivariable logistic regression, and a nomogram was drawn for DKD risk assessment.

RESULTS

Two prediction models for DKD were built by multivariate logistic regression analysis. Model 1 was created based on 17 variables using the forward selection method, Model 2 was established by 19 variables using the backward elimination method. The Somers' D values of both models were 0.789. Four independent predictors were selected to build the nomogram, including age, UACR, eGFR, and neutrophil percentages. The C-index of the nomogram reached 0.864, suggesting a good predictive accuracy for DKD development.

CONCLUSIONS

Our prediction models had strong predictive powers, and our nomogram provided visual aids to DKD risk calculation, which was simple and fast. These algorithms can provide early DKD risk prediction, which might help to improve the medical care for early detection and intervention in T2DM patients, and then consequently improve the prognosis of DM patients.

Novel lncRNA-prader willi/angelman region RNA, SNRPN neighbour (PWARSN) aggravates tubular epithelial cell pyroptosis by regulating TXNIP via dual way in diabetic kidney disease

OBJECTIVES

Elevated thioredoxin-interacting protein (TXNIP)-induced pyroptosis contributes to the pathology of diabetic kidney disease (DKD). However, the molecular mechanisms in dysregulated TXNIP in DKD remain largely unclear.

MATERIALS AND METHODS

Transcriptomic analysis identified a novel long noncoding RNA-Prader Willi/Angelman region RNA, SNRPN neighbour (PWARSN)-which was highly expressed in a proximal tubular epithelial cell (PTEC) under high glucose conditions. We focused on revealing the functions of PWARSN in regulating TXNIP-mediated pyroptosis in PTECs by targeting PWARSN expression via lentivirus-mediated overexpression and CRISPR-Cas9-based knockout in vitro and overexpressing PWARSN in the renal cortex by AAV-9 targeted injection in vivo. A number of molecular techniques disclosed the mechanisms of PWARSN in regulating TXNIP induced-pyroptosis in DKD.

RESULTS

TXNIP-NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome and PTEC pyroptosis were activated in the renal tubules of patients with DKD and in diabetic mice. Then we explored that PWARSN enhanced TXNIP-driven PTECs pyroptosis in vitro and in vivo. Mechanistically, cytoplasmic PWARSN sponged miR-372-3p to promote TXNIP expression. Moreover, nuclear PWARSN interacted and facilitated RNA binding motif protein X-linked (RBMX) degradation through ubiquitination, resulting in the initiation of TXNIP transcription by reducing H3K9me3-enrichment at the TXNIP promoter. Further analysis indicated that PWARSN might be a potential biomarker for DKD.

CONCLUSIONS

These findings illustrate distinct dual molecular mechanisms for PWARSN-modulated TXNIP and PTECs pyroptosis in DKD, presenting PWARSN as a promising therapeutic target for DKD.

Recent Advances in the Emerging Therapeutic Strategies for Diabetic Kidney Diseases

Diabetic kidney disease (DKD) is one of the most common causes of end-stage renal disease worldwide. The treatment of DKD is strongly associated with clinical outcomes in patients with diabetes mellitus. Traditional therapeutic strategies focus on the control of major risk factors, such as blood glucose, blood lipids, and blood pressure. Renin–angiotensin–aldosterone system inhibitors have been the main therapeutic measures in the past, but the emergence of sodium–glucose cotransporter 2 inhibitors, incretin mimetics, and endothelin-1 receptor antagonists has provided more options for the management of DKD. Simultaneously, with advances in research on the pathogenesis of DKD, some new therapies targeting renal inflammation, fibrosis, and oxidative stress have gradually entered clinical application. In addition, some recently discovered therapeutic targets and signaling pathways, mainly in preclinical and early clinical trial stages, are expected to provide benefits for patients with DKD in the future. This review summarizes the traditional treatments and emerging management options for DKD, demonstrating recent advances in the therapeutic strategies for DKD.

Tripterygium glycoside tablet attenuates renal function impairment in diabetic nephropathy mice by regulating triglyceride metabolism

Tripterygium glycoside tablet (TGT) has been used clinically to alleviate diabetic nephropathy (DN) for decades. However, the mechanism of its anti-DN has not been fully clarified. The aim of this study was to elucidate molecular mechanism of TGT in repairing renal function injury. The results of biochemical parameters and renal histopathology implied that TGT intervention could attenuate creatinine, albumin excretion rate and histological injury of kidney in DN mouse model. Moreover, UHPLC-QTOF-MS/MS-based untargeted metabolomic analysis indicated that 11 metabolites in kidney of mice with DN were restored after TGT treatment, and the most prominent metabolic alteration was triglyceride (TG) metabolism. Mechanistically, TGT effectively improved the function of impaired kidney by promoting TG catabolism via modulation of adipose triglyceride lipase in DN mice. Our findings identified the link between circulating metabolites and DN, suggesting that it might be a possibility to intervene in DN by targeting metabolism.

12(S)-hydroxyeicosatetraenoic acid is significantly increased in diabetic kidney disease and associated with renal function decline

AIMS

12(S)-hydroxyeicosatetraenoic (12(S)-HETE), an alternate arachidonic acid metabolite, has been recently examined in metabolic disease. However, the role of 12(S)-HETE in diabetic kidney disease (DKD) remains unclear. We studied for the first time the relationship of serum 12(S)-HETE and DKD and renal function parameters in a Chinese population.

MATERIALS AND METHODS

We recruited 275 subjects who were diagnosed with type 2 diabetes (T2DM) for more than 10 years, including 149 DKD patients and 126 T2DM patients without DKD. Serum 12(S)-HETE was measured using the enzyme-linked immunosorbent assay.

RESULTS

Serum 12(S)-HETE was significantly higher in DKD patients than controls [384.69 (77.54, 1003.05) pg/ml and 17.77 (8.11, 75.13) pg/ml, respectively, p < 0.0001]. Compared to controls, 12(S)-HETE was significantly increased in both macroalbuminuria and microalbuminuria groups (p < 0.0001). Further, the macroalbuminuria group also had a higher serum 12(S)-HETE level compared to the microalbuminuria group (p = 0.0063). Moreover, serum 12(S)-HETE was positively correlated with the albuminuria level (r = 0.5833, p < 0.0001), serum creatinine (r = 0.2725, p < 0.0001), and was negatively associated with the estimated glomerular filtration rate (r = -0.2085, p = 0.0005). Further, receiver operating characteristic analysis (ROC) revealed that 12(S)-HETE had a good performance of distinguishing DKD from controls (AUC 0.828) with a sensitivity of 0.913 and a specificity of 0.711.

CONCLUSION

Our findings revealed that serum 12(S)-HETE significantly associated with DKD and disease severity, suggesting that serum 12(S)-HETE may be used as a potential biomarker for the early diagnosis of DKD.

Targeting inflammation for the treatment of Diabetic Kidney Disease: a five-compartment mechanistic model

Diabetic kidney disease (DKD) is the leading cause of kidney failure worldwide. Mortality and morbidity associated with DKD are increasing with the global prevalence of type 2 diabetes. Chronic, sub-clinical, non-resolving inflammation contributes to the pathophysiology of renal and cardiovascular disease associated with diabetes. Inflammatory biomarkers correlate with poor renal outcomes and mortality in patients with DKD. Targeting chronic inflammation may therefore offer a route to novel therapeutics for DKD. However, the DKD patient population is highly heterogeneous, with varying etiology, presentation and disease progression. This heterogeneity is a challenge for clinical trials of novel anti-inflammatory therapies. Here, we present a conceptual model of how chronic inflammation affects kidney function in five compartments: immune cell recruitment and activation; filtration; resorption and secretion; extracellular matrix regulation; and perfusion. We believe that the rigorous alignment of pathophysiological insights, appropriate animal models and pathology-specific biomarkers may facilitate a mechanism-based shift from recruiting ‘all comers’ with DKD to stratification of patients based on the principal compartments of inflammatory disease activity.

Negative association of time in range and urinary albumin excretion rate in patients with type 2 diabetes mellitus: a retrospective study of inpatients

Background:

Time in range (TIR) refers to the time an individual spends within their target glucose range, which now has been popularized as an important metric to classify glycemic management and also recognized as an important outcome of current diabetes therapies. This study aimed to investigate the association between TIR and the severity of the urinary albumin excretion rate (UAER) in patients with type 2 diabetes mellitus (T2DM).

Methods:

We retrospectively analyzed the data of 1014 inpatients with T2DM at the Department of Endocrinology and Metabolism of Peking University International Hospital, China. TIR was defined as the percentage of blood glucose within the target range of 3.90–10.00 mmol/L. Urine samples for assessment of UAER were collected for 3 consecutive days from the start of hospitalization.

Results:

The TIR values for patients with normal urine levels of albumin, microalbuminuria, and macroalbuminuria were 70% ± 20%, 50% ± 20%, and 30% ± 20%, respectively (all P < 0.001). The patients were stratified according to quartiles of TIR as follows: quartile (Q) 1, <55%; Q2, 55%–72%; Q3, 73%–83%; and Q4, >83%. The incidences of microalbuminuria in Q1, Q2, Q3, and Q4 were 41.1%, 21.6%, 7.1%, and 5.5% (all P < 0.001), respectively. The respective incidences of macroalbuminuria were 24.2%, 1.1%, 1.4%, and 0% (all P < 0.001). In multinomial logistic regression analyses, TIR was significantly correlated with microalbuminuria (odds ratio [OR] 0.58, 95% confidence interval [CI]: 0.52–0.65, P < 0.001) and macroalbuminuria (OR 0.26, 95% CI: 0.18–0.38, P < 0.001) after adjusting for age, sex, body mass index, diabetes duration, systolic blood pressure, and levels of triglycerides, glycosylated hemoglobin A1c, and creatinine.

Conclusion:

The proportion of blood glucose in TIR is closely related to the severity of UAER in patients with T2DM.

Role and Mechanism of the Renin-Angiotensin-Aldosterone System in the Onset and Development of Cardiorenal Syndrome

Cardiorenal syndrome (CRS), a clinical syndrome involving multiple pathological mechanisms, exhibits high morbidity and mortality. According to the primary activity of the disease, CRS can be divided into cardiorenal syndrome (type I and type II), renal heart syndrome (type III and type IV), and secondary heart and kidney disease (type V). The renin-angiotensin-aldosterone system (RAAS) is an important humoral regulatory system of the body that exists widely in various tissues and organs. As a compensatory mechanism, the RAAS is typically activated to participate in the regulation of target organ function. RAAS activation plays a key role in the pathogenesis of CRS. The RAAS induces the onset and development of CRS by mediating oxidative stress, uremic toxin overload, and asymmetric dimethylarginine production. Research on the mechanism of RAAS-induced CRS can provide multiple intervention methods that are of great significance for reducing end-stage organ damage and further improving the quality of life of patients with CRS.

Methylglyoxal induces ambience for cancer promotion in HepG2 cells via Warburg effect and promotes glycation

Methylglyoxal (MGO) is a toxic, highly reactive metabolite derived mainly from glucose and amino acids degradation. MGO is also one of the prime precursors for advanced glycation end products formation. The present research was performed to check whether MGO has any role in the promotion of cancer in HepG2 cells. For this, cells were incubated with MGO (50 µM) for 24 h and subjected to various analyses. Aminoguanidine (200 µM) was positive control. The various biochemical and protein expression studies, relevant to the MGO detoxification system, oxidative stress, and glycolysis were performed. MGO caused the reduction of expression of GLO 1 (27%) and GLO 2 (11%) causing weakening of the innate detoxification system. This is followed by an increase of RAGE (95%), AGEs or methylglyoxal adducts. We also observed hypoxia via estimation of oxygen consumption rate and surplus reactive oxygen species (ROS) (24%). To investigate the off-target effect of MGO we checked its effect on glucose transport, and its associated proteins. Glucose uptake was found to increase (15%) significantly with overexpression of GLUT 1 (35%). We also found a significant increase of glycolytic enzymes such as hexokinase II, phosphofructokinase 1, and lactate dehydrogenase along with lactate production. Observation of surplus ROS and enhanced glycolysis led us to check the expression of HIF 1α which is their downstream signaling pathway. Interestingly HIF 1α was found to increase significantly (35%). It is known that enhanced glycolysis and oxidative stress are catalysts for the overexpression of HIF 1α which in turn creates an ambience for the promotion of cancer. Aminoguanidine was able to prevent the adverse effect of MGO partially. This is the first study to show the potential of MGO for the promotion of cancer in the non-tumorigenic HepG2 cells via the Warburg effect and glycation.

Potential effects and application prospect of angiotensin receptor-neprilysin inhibitor in diabetic kidney disease

Diabetic kidney disease (DKD) is one of the main causes of end-stage renal disease (ESRD) and all-cause mortality in diabetic patients, despite the extensive use of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB). Angiotensin receptor-neprilysin inhibitor (ARNI), combining ARB and neutral endopeptidase inhibitor (NEPI), is likely to have potential favorable effects in DKD. This review summarizes existing preclinical and clinical studies on mechanism of ARNI and its potential effects on DKD. In preclinical studies, ARNI manifested its renoprotective effects by improving natriuresis, ameliorating inflammation, oxidative stress and renal dysfunction, and slowing down glomerulosclerosis and tubulointerstitial injury of kidney, but its effect on proteinuria is still controversial. Beneficial effects of ARNI on blood glucose regulation and glycometabolism have also been reported. There are no clinical studies of ARNI that specifically focus on DKD patients so far. ARNI has application potential in DKD, but there still need clinical studies that focus on DKD patients to determine its effectiveness, safety and underlying mechanism.

[Oxymatrine improves renal fibrosis and inflammation in diabetic rats by modulating CHK1/2 phosphorylation]

OBJECTIVE

To explore the role of cell cycle checkpoint kinase 1/2 (CHK1/2) in mediating the inhibitory effect of oxymatrine (OMT) against renal inflammation and fibrosis in diabetic rats.

METHODS

SD rats were randomly divided into normal control group, diabetes model group (DM) and OMT treatment group (n=6). HE and Masson staining were used to observe histopathological changes of the renal tissue, and the expressions of CHK1, CHK2, p-CHK1 and p-CHK2 were localized by immunohistochemical staining. The contents of interleukin-6 (IL-6) and IL-1β in the renal tissue were detected using ELISA, and the expression levels of CHK1, CHK2, p-CHK1, p-CHK2, type Ⅲ collagen (Col-Ⅲ), type Ⅳ collagen (Col-Ⅳ), and fibronectin (FN) were determined using Western blotting. The changes in the expressions of CHK1, CHK2, p-CHK1, p-CHK2, Col-Ⅲ, Col-Ⅳ and FN proteins were also examined with Western blotting in NRK-52E cells in response to high glucose exposure, OMT treatment and siRNA-mediated CHK1/2 knockdown.

RESULTS

In diabetic rats, OMT treatment significantly decreased the levels of blood glucose, serum creatinine and 24 h urinary protein (P < 0.05) and obviously improved inflammatory cell infiltration and fibrosis phenotype in the renal tissue (P < 0.05). CHK1 and CHK2 were mainly expressed in the cytoplasm and nuclei of renal tubule cells, and their phosphorylation levels were significantly higher in DM group than in the control group and OMT group. OMT treatment significantly decreased the protein expression levels of p-CHK1, p-CHK2, Col-Ⅲ, Col-Ⅳ and FN in the renal tissue of diabetic rats and in NRK-52E cells exposed to high glucose (P < 0.05). In NRK-52E cells, CHK1/2 knockdown resulted in significant reduction of the protein expressions of p-CHK1/2, Col-Ⅲ, Col-Ⅳ and FN (P < 0.05).

CONCLUSION

The inhibitory effects of OMT against renal inflammation and fibrosis in diabetic rats are mediated probably by lowered phosphorylation levels of CHK1 and CHK2, which result in reduced release of the downstream inflammatory mediators and decreased secretion and deposition of extracellular matrix.

Should We Be Concerned about the Association of Diabetes Mellitus and Periodontal Disease in the Risk of Infection by SARS-CoV-2? A Systematic Review and Hypothesis

The objective of this article was to conduct a systematic review of the literature to contrast the existing evidence regarding the relationship between periodontal disease (PD) and diabetes mellitus (DM) with the possibly increased risk of SARS-CoV-2 infection, as well as to establish a hypothesis that explains the ways in which this interaction could take place. A literature search up from 1 January 2020 to 21 March 2021 was conducted in three electronic databases, namely, PubMed, Web of Science, and Scopus, in order to identify studies on periodontal disease alone or in conjunction with diabetes mellitus, reporting any relation with SARS-CoV-2 infection as a primary outcome. Only articles published in the English language were included. Due to the lack of studies, we decided to collect all the theoretical and clinical evidence suggesting a possible biological pathway evidencing the relationship among PD, DM, and SARS-CoV-2 infection. From a total of 29 articles, 12 were included for final review studies (five reviews, two hypotheses, one Special Issue, one perspective, one commentary, one case–control study, and one case report). In addition, this systematic review article hypothesizes the correlation between PD and type 2 diabetes mellitus (T2DM) by expression of angiotensin-converting enzyme 2 (ACE2) in periodontal tissue and the risk of SARS-CoV-2 infection. T2DM is a metabolic disorder characterized by high blood glucose levels resulting from altered insulin secretion or action. Likewise, periodontitis and T2DM are inflammatory disorders with a bidirectional association, and both diseases have a similar immunomodulatory cascade and cytokine profile. ACE2 is a crucial component of the renin–angiotensin system (RAS) and the key factor of entry in the cells by the new SARS-CoV-2. ACE2 is widely distributed in the lung and kidneys, and interestingly has a great distribution in the oral cavity, principally in the tongue and periodontal tissue. ACE2 in periodontal tissue plays a crucial role between health and disease. Moreover, the ACE2/Ang-(1-7)/MasR axis is downregulated in the dysbiotic and inflammatory periodontal environment. Nevertheless, the balance of ACE2 activity is modified in the context of concurrent diabetes, increasing the expression of ACE2 by the uncontrolled glycemia chronic in T2DM. Therefore, the uncontrolled hyperglycemia possibly increases the risk of developing periodontitis and triggering overexpression of ACE2 in periodontal tissue of T2DM patients, with these events potentially being essential to SARS-CoV-2 infection and the development of mild-to-severe form of COVID-19. In this sense, we would like to point out that the need for randomized controlled trials is imperative to support this association.

CD28 Genetic Variants Increase Susceptibility to Diabetic Kidney Disease in Chinese Patients with Type 2 Diabetes: A Cross-Sectional Case Control Study

Few studies have illuminated the genetic role of T cell costimulatory molecule CD28/CD80/CTLA4 variants in diabetic kidney disease (DKD) susceptibility. We aimed to investigate the causal role of genetic polymorphisms in CD28/CD80/CTLA4 with DKD susceptibility in patients with T2DM. A total of 3253 patients with T2DM were recruited for genotyping: including 204 DKD patients and 371 controls in stage 1 and 819 DKD patients and 563 controls in stage 2; besides, 1296 T2DM patients were selected for the analysis of association between loci and DKD-related traits. A subset of 227 T2DM patients (118 patients with DKD and 109 patients without DKD) from the total population above were selected to assess serum soluble CD28 (sCD28) levels. Then, we performed a candidate gene association study to identify single-nucleotide polymorphisms (SNPs) associated with DKD susceptibility and further used those SNPs to perform Mendelian randomization analyses of serum sCD28 level and DKD susceptibility. Under additive genetic models, CD28-rs3116494 (OR = 1.29 [95% CI 1.11, 1.51], P = 0.0011) and CD80-rs3850890 (OR = 1.16 [95% CI 1.02, 1.31], P = 0.0283) were associated with DKD susceptibility adjusted for age, gender, body mass index (BMI), duration of diabetes, and HbA1c. CD28-rs3116494 was associated with serum sCD28 level (β = 0.26 [95% CI 0.08, 0.44], P = 0.0043). The Mendelian randomization analysis showed that CD28-rs3116494 played a causal role in DKD by influencing serum sCD28 levels (β = 1.15 [95% CI 0.46, 1.83], P = 0.0010). In conclusion, we identified that two novel SNPs, CD28-rs3116494 and CD80-rs3850890, were associated with DKD susceptibility. Using the Mendelian randomization analysis, our study provided evidence for a causal relationship between serum CD28 levels and DKD with T2DM in the Chinese population.

Non-Coding RNAs as Biomarkers and Therapeutic Targets for Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the most common diabetic complication and is a leading cause of end-stage kidney disease. Increasing evidence shows that DKD is regulated not only by many classical signaling pathways but also by epigenetic mechanisms involving chromatin histone modifications, DNA methylation, and non-coding RNA (ncRNAs). In this review, we focus on our current understanding of the role and mechanisms of ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in the pathogenesis of DKD. Of them, the regulatory role of TGF-β/Smad3-dependent miRNAs and lncRNAs in DKD is highlighted. Importantly, miRNAs and lncRNAs as biomarkers and therapeutic targets for DKD are also described, and the perspective of ncRNAs as a novel therapeutic approach for combating diabetic nephropathy is also discussed.

Association of Urinary Sodium Excretion and Diabetic Kidney Disease in Patients With Type 2 Diabetes Mellitus: A Cross-Sectional Study

BACKGROUND

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease worldwide. Epidemiological evidence of the association between urinary sodium excretion and the presence of DKD in patients with type 2 diabetes mellitus (T2DM) has not yet been well established.

METHODS

We performed a cross-sectional study of 1545 patients with T2DM over aged 20 years old from January 2018 to December 2020. Urinary sodium excretion was measured by 24-hour urine samples in inpatients and morning fasting urine samples in outpatients. The associations between urinary sodium excretion and the risks of DKD were examined using stepwise regression analysis, logistic regression analysis and multivariable-adjusted restricted cubic splines (RCS).

RESULTS

Regression analysis showed that urinary sodium was independently associated with urinary albumin to creatinine ratio (UACR) level (P = 0.006) and the risks of DKD (P = 0.042). In multivariable-adjusted RCS analysis, urinary sodium excretion was significantly associated with UACR in all patients (P = 0.008), and exhibited a J-shaped relationship. Logistic regression analysis showed that increased urinary sodium excretion was significantly associated with increased risks of DKD [OR (95% CI); 1.56 (1.07-2.27); P = 0.020]. However, the relationships between urinary sodium excretion and the risks of DKD and albuminuria showed no significance, after further adjustment for HOMA-IR and ba-PWV (brachial-ankle pulse wave velocity) (Both P > 0.05).

CONCLUSIONS

Higher urinary sodium excretion level was associated with increased risks of DKD among patients with T2DM, dependent of vascular sclerosis and insulin resistance.

Lipid Accumulation Product is Associated with Urinary Albumin-creatinine Ratio in Chinese Prediabitic Population: A Report from the REACTION Study

BACKGROUND

Lipid accumulation product (LAP) as a powerful marker of visceral obesity is an independent risk factor of chronic kidney disease. The present study attempted to explore the association between LAP and albuminuria in prediabetic individuals.

METHODS

We conducted a cross-sectional study and enrolled 26,529 participants with prediabetes over 40 years old with prediabetes from seven provinces in China. LAP was calculated from waist circumference and fasting triglycerides. Elevated albuminuria was defined by urinary albumin-creatinine ratio (uACR) ≥30 mg/g. Propensity score matching was applied to reduce bias, comparison between LAP and other traditional visceral obesity indices was performed and multiple logistic regression models were conducted to assess the association between LAP and albuminuria in the prediabetic population.

RESULTS

Individuals with uACR ≥30 mg/g were older and had higher BP, BMI, WC, TG, fasting insulin, glycohemoglobin and LAP, as well as lower eGFR and HDL level. Multiple logistic regression analysis showed elevated LAP was associated with increased odds of albuminuria (OR [95%CI]_{Q2 vs Q1} 1.09 [0.94, 1.27], OR [95%CI]_{Q3 vs Q1} 1.13 [0.97, 1.31], OR [95%CI]_{Q4 vs Q1} 1.42 [1.21, 1.67], P for trend=0.018), and superior over waist-to-hip ratio or waist-to-height ratio. Stratification indicated that the prediabetic population with higher LAP level and characterized by female gender, middle age, being overweight, and rise in blood pressure were more likely to have increased uACR.

CONCLUSION

Elevated level of LAP was associated with increased albuminuria in the prediabetic population in China.

Decreased Urinary Levels of SIRT1 as Non-Invasive Biomarker of Early Renal Damage in Hypertension

Sirtuins have become important players in renal damage in hypertension and diabetes, but their value as biomarkers is poorly assessed. The aims of the study were to evaluate the levels of sirtuin1 (SIRT1), and two miRNAs that regulate SIRT1 expression in hypertensive patients with incipient renal damage with and without diabetes. We quantified urinary SIRT1 and claudin 1 (CLDN1) mRNA and miR34-a and miR-200a levels by quantitative real-time polymerase chain reaction (RT-qPCR) from patients and in cultured podocytes treated with high glucose and angiotensin II. Western blot and fluorescence analyses were also performed. We found decreased SIRT1 levels in patients with increased urinary albumin excretion (UAE), the lowest with diabetes presence, and a strong association with UAE, discriminating incipient renal damage. In vitro experiments also showed SIRT1 overall decreases in podocyte cultures under treatment conditions. In urine samples, miR-34a was reduced and miR-200a increased, both related to UAE levels. However, both miRNAs were generally increased in podocyte cultures under high glucose and angiotensin-II treatment. These results show a significant urinary SIRT1 decrease in albuminuric hypertensive patients, strongly associated with albuminuria, suggesting that SIRT1 could be a potential and non-invasive method to assess incipient renal damage in hypertensive patients.

The Peculiarity of Process and Treatment of Arterial Hypertension in Patients with Type 2 Diabetes Mellitus

Arterial hypertension (AH) is powerful and modifying factor of developing macrovascular and microvascular complications of diabetes. Patients with AH and diabetes belong to group with high and very high levels risk of developing cardiovascular complications and chronic kidney disease. The combination of type 2 diabetes mellitus and AH dramatically increases the risk of developing terminal stages of microvascular and macrovascular diabetic complications: blindness, end-stage chronic kidney disease, amputation of the lower extremities, myocardial infarction, cerebral stroke, worsens the patients prognosis and quality of life. There is ample evidence that blood pressure control in diabetic patients may be critical for improving long-term prognosis. This observation does not lose its relevance even with the emergence of new antidiabetic drugs with proven cardio- and nephroprotective effects. Modern clinical researchers and meta-analysis show the priority of combined antihypertensive therapy, which increases the efficacy of blood pressure correction and prophylaxis of long-term complications in patients with type 2 diabetes. In this article we want to pay attention to features of AH in patients with diabetes, to bi-directional pathogenic mechanisms, to discuss the new algorithms of the treatment and therapeutic needs of these patients. It is important to accent the understanding of the integrity and unity of pathogenic mechanisms which are needed in correction. Innovative antihyperglycemic therapy demonstrates the ability of blood pressure decrease. The synergy of effects let us successfully realize the strategy of multi-factor control and reduce a risk of micro- and macrovascular complications.