Therapies on the Horizon for Diabetic Kidney Disease

Risk factors of foot ulcers in patients with end-stage renal disease on dialysis: A meta-analysis

The present study aims to assess the risk factors for foot ulcers in patients undergoing dialysis for end-stage renal disease (ESRD) and to provide evidence-based guidance for prevention and treatment. A systematic search was conducted on PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database and Wanfang Data from the database inception until May 2023 to identify relevant studies investigating the risk factors for foot ulcers in dialysis patients with ESRD. Two independent researchers conducted the literature screening and data extraction. The meta-analysis was performed using STATA 17.0 software. Ultimately, six articles comprising 1620 patients were included for analysis. The meta-analysis revealed that male (OR, 1.464; 95% CI: 1.082-1.980, p = 0.013), hypertension (OR, 1.781; 95% CI: 1.293-2.4550, p < 0.001), peripheral artery disease (PAD) (OR, 5.014; 95% CI: 2.514-9.998, p < 0.001), type 1 diabetes mellitus (T1DM) (OR, 2.993; 95% CI: 1.477-6.065, p = 0.002) and type 2 diabetes mellitus (T2DM) (OR, 2.498; 95% CI:1.466-4.256, p = 0.001) were risk factors for foot ulcers in dialysis patients with ESRD. Conversely, the female sex (OR, 0.683; 95% CI: 0.505-0.924, p = 0.013) was a protective factor against foot ulcers. Our analysis revealed that male sex, hypertension, PAD, T1DM and T2DM were risk factors for foot ulcers in patients undergoing dialysis for ESRD. Conversely, the female sex was a protective factor against foot ulcers. Therefore, it is crucial to strengthen health education that targets patients with these risk factors and regularly screen high-risk individuals. Early detection and treatment can help delay disease progression.

Pathomechanisms of Diabetic Kidney Disease

The worldwide occurrence of diabetic kidney disease (DKD) is swiftly rising, primarily attributed to the growing population of individuals affected by type 2 diabetes. This surge has been transformed into a substantial global concern, placing additional strain on healthcare systems already grappling with significant demands. The pathogenesis of DKD is intricate, originating with hyperglycemia, which triggers various mechanisms and pathways: metabolic, hemodynamic, inflammatory, and fibrotic which ultimately lead to renal damage. Within each pathway, several mediators contribute to the development of renal structural and functional changes. Some of these mediators, such as inflammatory cytokines, reactive oxygen species, and transforming growth factor β are shared among the different pathways, leading to significant overlap and interaction between them. While current treatment options for DKD have shown advancement over previous strategies, their effectiveness remains somewhat constrained as patients still experience residual risk of disease progression. Therefore, a comprehensive grasp of the molecular mechanisms underlying the onset and progression of DKD is imperative for the continued creation of novel and groundbreaking therapies for this condition. In this review, we discuss the current achievements in fundamental research, with a particular emphasis on individual factors and recent developments in DKD treatment.

Pericyte Loss in Diseases

Pericytes are specialized cells located in close proximity to endothelial cells within the microvasculature. They play a crucial role in regulating blood flow, stabilizing vessel walls, and maintaining the integrity of the blood-brain barrier. The loss of pericytes has been associated with the development and progression of various diseases, such as diabetes, Alzheimer's disease, sepsis, stroke, and traumatic brain injury. This review examines the detection of pericyte loss in different diseases, explores the methods employed to assess pericyte coverage, and elucidates the potential mechanisms contributing to pericyte loss in these pathological conditions. Additionally, current therapeutic strategies targeting pericytes are discussed, along with potential future interventions aimed at preserving pericyte function and promoting disease mitigation.

The Glomerulus Multiomics Analysis Provides Deeper Insights into Diabetic Nephropathy

Although diabetic nephropathy (DN) is the leading cause of the end-stage renal disease, the exact regulation mechanisms remain unknown. In this study, we integrated the transcriptomics and proteomics profiles of glomeruli isolated from 50 biopsy-proven DN patients and 25 controls to investigate the latest findings about DN pathogenesis. First, 1152 genes exhibited differential expression at the mRNA or protein level, and 364 showed significant association. These strong correlated genes were divided into four different functional modules. Moreover, a regulatory network of the transcription factors (TFs)-target genes (TGs) was constructed, with 30 TFs upregulated at the protein levels and 265 downstream TGs differentially expressed at the mRNA levels. These TFs are the integration centers of several signal transduction pathways and have tremendous therapeutic potential for regulating the aberrant production of TGs and the pathological process of DN. Furthermore, 29 new DN-specific splice-junction peptides were discovered with high confidence; these peptides may play novel functions in the pathological course of DN. So, our in-depth integrative transcriptomics-proteomics analysis provided deeper insights into the pathogenesis of DN and opened the potential avenue for finding new therapeutic interventions. MS raw files were deposited into the proteomeXchange with the dataset identifier PXD040617.

Translation Animal Models of Diabetic Kidney Disease: Biochemical and Histological Phenotypes, Advantages and Limitations

Animal models play a crucial role in studying the pathogenesis of diseases, developing new drugs, identifying disease risk markers, and improving means of prevention and treatment. However, modeling diabetic kidney disease (DKD) has posed a challenge for scientists. Although numerous models have been successfully developed, none of them can encompass all the key characteristics of human DKD. It is essential to choose the appropriate model according to the research needs, as different models develop different phenotypes and have their limitations. This paper provides a comprehensive overview of biochemical and histological phenotypes, modeling mechanisms, advantages and limitations of DKD animal models, in order to update relevant model information and provide insights and references for generating or selecting the appropriate animal models to fit different experimental needs.

Nephroprotective Effects of Tetramethylpyrazine Nitrone TBN in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of end-stage renal failure, but therapeutic options for nephroprotection are limited. Oxidative stress plays a key role in the pathogenesis of DKD. Our previous studies demonstrated that tetramethylpyrazine nitrone (TBN), a novel nitrone derivative of tetramethylpyrazine with potent free radical-scavenging activity, exerted multifunctional neuroprotection in neurological diseases. However, the effect of TBN on DKD and its underlying mechanisms of action are not yet clear. Herein, we performed streptozotocin-induced rat models of DKD and found that TBN administrated orally twice daily for 6 weeks significantly lowered urinary albumin, N-acetyl-β-D-glycosaminidase, cystatin C, malonaldehyde, and 8-hydroxy-2′-deoxyguanosine levels. TBN also ameliorated renal histopathological changes. More importantly, in a nonhuman primate model of spontaneous stage III DKD, TBN increased the estimated glomerular filtration rate, decreased serum 3-nitrotyrosine, malonaldehyde and 8-hydroxy-2′-deoxyguanosine levels, and improved metabolic abnormalities. In HK-2 cells, TBN increased glycolytic and mitochondrial functions. The protective mechanism of TBN might involve the activation of AMPK/PGC-1α-mediated downstream signaling pathways, thereby improving mitochondrial function and reducing oxidative stress in the kidneys of DKD rodent models. These results support the clinical development of TBN for the treatment of DKD.

Multifunctional agents based on benzoxazolone as promising therapeutic drugs for diabetic nephropathy

Diabetic nephropathy (DN) is resulted from activations of polyol pathway and oxidative stress by abnormal metabolism of glucose, and no specific medication is available. We designed a novel class of benzoxazolone derivatives, and a number of individuals were found to have significant antioxidant activity and inhibition of aldose reductase of the key enzyme in the polyol pathway. The outstanding compound (E)-2-(7-(4-hydroxy-3-methoxystyryl)-2-oxobenzo[d]oxazol-3(2H)-yl)acetic acid was identified to reduce urinary proteins in diabetic mice suggesting an alleviation in the diabetic nephropathy, and this was confirmed by kidney hematoxylin-eosin staining. Further investigations showed blood glucose normalization, declined in the polyol pathway and lipid peroxides, and raised glutathione and superoxide dismutase activity. Thus, we suggest a therapeutic function of the compound for DN which could be attributed to the combination of hypoglycemic, aldose reductase inhibition and antioxidant.

Danhong injection for the treatment of early diabetic nephropathy: A protocol of systematic review and meta-analysis

BACKGROUND

Diabetic nephropathy (DN) is the one that of the most common complications of diabetes mellitus (DM). Diabetic patients will experience a high mortality rate when DN progress to end-stage. So, it is extremely important to early treat DN. Although several interventions have been used to treat DN, a conclusive finding has not already been achieved. As one of the most common Chinese medicines, danhong injection (DHI) which has been shown to have various functions has also been prescribed to be as the alternative treatment option. However, no systematic review and meta-analysis has been conducted to objectively and comprehensively investigate its effectiveness and safety. Thus, we designed the current systematic review and meta-analysis to answer whether DHI can be preferably used to timely treat DN.

METHODS

We will perform a systematic search to capture any potentially eligible studies in several electronic databases including PubMed, Cochrane library, Embase, China National Knowledgement Infrastructure (CNKI), Wanfang database, and Chinese sci-tech periodical full-text database (VIP) from their inception to August 31, 2020. We will assign 2 independent reviewers to select eligible studies, and assess the quality of included studies with Cochrane risk of bias assessment tool. We will perform all statistical analyses using RevMan 5.3 software.

ETHICS AND DISSEMINATION

We will submit our findings to be taken into consideration for publication in a peer-reviewed academic journal. Meanwhile, we will also communicate our findings in important conferences.

PROTOCOL REGISTRY

The protocol of this systematic review and meta-analysis has been registered at the International Plateform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) platform (https://inplasy.com/inplasy-2020-9-0005/, registry number: INPLASY202090005) and this protocol was funded through a protocol registry.

Clinical efficacy and safety of Chinese herbal medicine for the treatment of patients with early diabetic nephropathy: A protocol for systematic review and meta-analysis

BACKGROUND

Diabetic nephropathy (DN) is among the common and serious complications of diabetes and is also a major cause of end-stage kidney disease. Early DN is also called diabetic microalbumin period, the main treatment is in the control of blood sugar on the basis of kidney protection and urine lowering protein. There are few effective methods of western medicine treatment, and most of them are accompanied by adverse reactions. But some studies have shown that traditional Chinese medicine has achieved the curative effect and has certain superiority. However, there are few systematic reviews on the treatment of traditional Chinese herbal medicine for early DN currently. Therefore, this study conducted a systematic review of clinical efficacy and safety of Chinese herbal medicine for the treatment of patients with early DN, aim to comprehensively analyze the role of traditional Chinese herbal medicine in the treatment of early DN.

METHODS AND ANALYSIS

The protocol of this systematic review and meta-analysis was registered on the INPLASY website (https://inplasy.com/inplasy-2020-4-0139/) and INPLASY registration number is INPLASY202040139. A systematic literature search will be conducted in 3 English database and 4 Chinese databases with a language limitation of English and Chinese. Search for clinical research literature on Chinese herbal medicine treatment of DN published in domestic and foreign biomedical journals. The time is limited from January 2010 to February 2020. We will investigate heterogeneity across studies and publication bias. To assess the risk of bias and quality of the included studies, we will use the Cochrane Collaboration's ROB tool. According to the relevant standards in the Cochrane Intervention System Evaluation Manual, it will be divided into low risk, high risk, and unclear. We will also use the RevMan 5.3 software and Stata 13.0 software for meta-analysis of the effectiveness and symptom scores of DN proteinuria.

ETHICS AND DISSEMINATION

The ethical considerations are not required because the systematic review is based on published studies. The systematic review and meta-analysis will be published in a peer-reviewed Journal.

Dietary EPA Increases Rat Mortality in Diabetes Mellitus, A Phenomenon Which Is Compensated by Green Tea Extract

Diabetes is characterized by a high mortality rate which is often associated with heart failure. Green tea and eicosapentaenoic acid (EPA) are known to lessen some of the harmful impacts of diabetes and to exert cardio-protection. The aim of the study was to determine the effects of EPA, green tea extract (GTE), and a combination of both on the cardiac consequences of diabetes mellitus, induced in Wistar rats by injection of a low dose of streptozotocin (33 mg/kg) combined with a high fat diet. Cardiac mechanical function, coronary reactivity, and parameters of oxidative stress, inflammation, and energy metabolism were evaluated. In the context of diabetes, GTE alone limited several diabetes-related symptoms such as inflammation. It also slightly improved coronary reactivity and considerably enhanced lipid metabolism. EPA alone caused the rapid death of the animals, but this effect was negated by the addition of GTE in the diet. EPA and GTE combined enhanced coronary reactivity considerably more than GTE alone. In a context of significant oxidative stress such as during diabetes mellitus, EPA enrichment constitutes a risk factor for animal survival. It is essential to associate it with the antioxidants contained in GTE in order to decrease mortality rate and preserve cardiac function.

Mitochondrial activity contributes to impaired renal metabolic homeostasis and renal pathology in STZ-induced diabetic mice

Diabetic nephropathy (DN) has become the main cause of end-stage renal disease worldwide, but the efficacy of current therapeutic strategies on DN remains unsatisfactory. Recent research has reported the involvement of metabolic rearrangement in the pathological process of DN, and of all the disturbances in metabolism, mitochondria serve as key regulatory hubs. In the present study, high-resolution mass spectrometry-based nontarget metabolomics was used to uncover the metabolic characteristics of the early diabetic kidney with or without the inhibition of mitochondrial activity. At first, we observed a moderate enhancement of mitochondrial complex-1 activity in the diabetic kidney, which was completely normalized by the specific mitochondrial complex-1 inhibitor rotenone (ROT). Meanwhile, metabolomics data indicated an overactivated pentose phosphate pathway, purine and pyrimidine metabolism, hexosamine biosynthetic pathway, and tricarboxylic acid cycle, which were strikingly corrected by ROT. In addition, ROT also strikingly corrected imbalanced redox homeostasis, possibly by increasing the ratio of antioxidant metabolites glutathione and NADPH against their oxidative form. In agreement with the improved metabolic status and oxidative response, ROT attenuated glomerular and tubular injury efficiently. Fibrotic markers (fibronectin, α-smooth muscle actin, collagen type I, and collagen type III), inflammatory factors (TNF-α, IL-1β, and ICAM-1), and oxidative stress were all markedly blocked by ROT. In vitro, ROT dose dependently attenuated high glucose-induced proliferation and extracellular matrix production in mesangial cells. Collectively, these findings revealed that the overactivation of mitochondrial activity in the kidney could contribute to metabolic disorders and the pathogenesis of early DN.

MicroRNA-326-3p ameliorates high glucose and ox-LDL-IC- induced fibrotic injury in renal mesangial cells by targeting FcγRIII

AIM

The aim of the present study was to identify the regulatory relationship between miR-326-3p and FcγRIII, and to explore the involvement of miR-326-3p/FcγRIII/TGF-β/Smad signalling pathway in fibrotic injury, which was induced by the high glucose (HG) and oxidized low density lipoprotein immune complex (ox-LDL-IC) in mouse glomerular mesangial cells (GMCs).

METHODS

Dual-luciferase reporter system and real time PCR (RT-PCR) were used to identify FcγRIII as a target gene of miR-326-3p. Lentiviral transduction was used to construct different expression of miR-326-3p in GMCs, which were divided into three groups: miR-326-3p mimics group (miR-326-3p group), miR-326-3p inhibitor group (miR-326-3p-inhibit group) and scramble control group (control group). Then, each group was stimulated by normal glucose (NG), HG, ox-LDL-IC and HG + ox-LDL-IC, respectively. RT-PCR and western blot were used to measure the expressions of Col-I, CTGF, α-SMA, TGF-β, Smad2/3 and pSmad2/3.

RESULTS

FcγRIII was regulated negatively by miR-326-3p in GMCs under the condition of HG and ox-LDL-IC, which implied FcγRIII as a target gene of miR-326-3p. Furthermore, compared with normal glucose group, the expressions of Col-I, CTGF, α-SMA, TGF-β and pSmad2/3 were higher under the condition of HG, ox-LDL-IC and HG + ox-LDL-IC (P < 0.05). In particular, miR-326-3p-inhibit groups exhibited the most significant increase (P < 0.05), while miR-326-3p could attenuate the increase (P < 0.05).

CONCLUSION

FcγRIII was identified as a target gene of miR-326-3p. MiR-326-3p/FcγRIII/TGF-β/Smad signaling pathway was investigated to be involved in the pathophysiology of renal fibrosis of DKD.

Evidence of altered brain network centrality in patients with diabetic nephropathy and retinopathy: an fMRI study using a voxel-wise degree centrality approach

BACKGROUND

Over recent years, some researchers believe that diabetic nephropathy (DN) and diabetic retinopathy (DR) both independently increase the incidence of brain diseases, such as stroke, cerebral infarction, and cerebral hemorrhage. In the present study, we used the voxel-wise degree centrality (DC) method to investigate potential changes of functional network brain activity in patients with DN and retinopathy (DNR).

METHODS

Twenty DNR patients (9 men, 11 women) and 20 healthy controls (HCs; 9 men, 11 women) were recruited; the controls were matched for age, sex, and educational background. All subjects underwent resting-state functional magnetic resonance imaging. Ophthalmoscopy, renal biopsy and single-photon emission computed tomography were used to evaluate microvascular lesions in the eye and kidney. Data were categorized using receiver operating characteristic curves, and correlation analysis was performed using Pearson's correlation analysis.

RESULTS

Compared with HCs, DNR patients showed reduced mean DC values in the right inferior temporal gyrus (RITG) and left subcallosal gyrus regions (LSG) and increased mean DC values in the bilateral precuneus (BP). Moreover, mean DC in the BP was correlated with renal estimated glomerular filtration rate (eGFR; r = 0.762). The area under the curve (AUC) value was 0.829 for BP and 0.839 for RITG and LSG.

CONCLUSION

DNR patients showed dysfunction in three different brain regions. The linear correlation between eGFR and mean brain DC values indicates the presence of common diabetic microangiopathy in the brain and kidney, which may provide new ideas for multiorgan microvascular lesions of diabetics.

Schisandrin B alleviates diabetic nephropathy through suppressing excessive inflammation and oxidative stress

Diabetic nephropathy (DN) is a progressive kidney disease due to glomerular capillary damage in diabetic patients, with inflammation and oxidative stress implicated as crucial pathogenic factors. There is an urgent need to develop effective therapeutic drug. Natural medicines are rich resources for active lead compounds. They would provide new opportunities for the treatment of DN. The present study was designed to investigate the protective effects of Schisandrin B (SchB) on DN and to delineate the underlying mechanism. Oral administration of SchB in the diabetic mouse model significantly alleviated hyperglycemia-induced renal injury, which was accompanied by maintenance of urine creatinine and albumin levels at similar to those of control non-diabetic mice. Histological examination of renal tissue indicated that both development of fibrosis and renal cell apoptosis were dramatically inhibited by SchB. The protective effect of SchB on DN associated with suppression of inflammatory response and oxidative stress. These results strongly suggested that SchB could be a potential therapeutic agent for treatment of DN. Moreover, our findings provided a fuller understanding of the regulatory role of NF-κB and Nrf2 in DN, indicating that they could be important therapeutic targets.

The Interaction of miR-378i-Skp2 Regulates Cell Senescence in Diabetic Nephropathy

Diabetic nephropathy (DN) is the major cause of end stage renal disease. Proximal tubular epithelial cell (PTEC) injury occurs early in diabetic kidney, and it is correlated with consequent renal failure. Cellular senescence participates in the pathophysiology of DN, but its role remains unclear. We conducted a cross-disciplinary study, including human, in vivo, and in vitro studies, to explore the novel molecular mechanisms of PTEC senescence in DN. We found that HG induced cell senescence in PTECs, supported by enhanced β-galactosidase staining, p53 and p27 expression, and reduced cyclin E levels. Transcriptome analysis of PTECs from a type 2 diabetic patient and a normal individual using next generation sequencing (NGS) and systematic bioinformatics analyses indicated that miR-378i and its downstream target S-phase kinase protein 2 (Skp2) contribute to HG-induced senescence in PTECs. High glucose (HG) elevated miR-378i expression in PTECs, and miR-378i transfection reduced Skp2 expression. Urinary miR-378i levels were elevated in both db/db mice and type 2 diabetic patients, whereas decreased Skp2 levels were shown in proximal tubule of db/db mice and human DN. Moreover, urinary miR-378i levels were positively correlated with urinary senescence-associated secretory phenotype cytokines and renal function in in vivo and human study. This study demonstrates that the interaction between miR-378i and Skp2 regulates PTEC senescence of DN. miR-378i has the potential to predict renal injury in DN. These findings suggest future applications in both therapy and in predicting renal dysfunction of DN.

Diabetes, Hypertension, and Cardiovascular Disease: Clinical Insights and Vascular Mechanisms

Hypertension and type 2 diabetes are common comorbidities. Hypertension is twice as frequent in patients with diabetes compared with those who do not have diabetes. Moreover, patients with hypertension often exhibit insulin resistance and are at greater risk of diabetes developing than are normotensive individuals. The major cause of morbidity and mortality in diabetes is cardiovascular disease, which is exacerbated by hypertension. Accordingly, diabetes and hypertension are closely interlinked because of similar risk factors, such as endothelial dysfunction, vascular inflammation, arterial remodelling, atherosclerosis, dyslipidemia, and obesity. There is also substantial overlap in the cardiovascular complications of diabetes and hypertension related primarily to microvascular and macrovascular disease. Common mechanisms, such as upregulation of the renin-angiotensin-aldosterone system, oxidative stress, inflammation, and activation of the immune system likely contribute to the close relationship between diabetes and hypertension. In this article we discuss diabetes and hypertension as comorbidities and discuss the pathophysiological features of vascular complications associated with these conditions. We also highlight some vascular mechanisms that predispose to both conditions, focusing on advanced glycation end products, oxidative stress, inflammation, the immune system, and microRNAs. Finally, we provide some insights into current therapies targeting diabetes and cardiovascular complications and introduce some new agents that may have vasoprotective therapeutic potential in diabetes.

EGFR inhibition attenuates diabetic nephropathy through decreasing ROS and endoplasmic reticulum stress

Diabetic nephropathy (DN) is a progressive kidney disease due to glomerular capillary damage in diabetic patients. Endoplasmic reticulum (ER) stress caused by reactive oxygen species (ROS) is associated with DN progression. Epidermal growth factor receptor (EGFR) mediates oxidative stress and damage of cardiomyocytes in diabetic mice. Here we demonstrated that AG1478, a specific inhibitor of EGFR, blocked EGFR and AKT phosphorylation in diabetic mice. Oxidative stress and ER stress markers were eliminated after AG1478 administration. AG1478 decreased pro-fibrotic genes TGF-β and collagen IV. Furthermore, we found that high glucose (HG) induced oxidative stress and ER stress, and subsequently increased ATF4 and CHOP. These changes were eliminated by either AG1478 or ROS scavenger N-acetyl-L-cysteine (NAC) administration. These results were confirmed by knock-down approaches in renal mesangial SV40 cells. However, AG1478, not NAC, reversed HG induced EGFR and AKT phosphorylation. These results suggest that EGFR/AKT/ROS/ER stress signaling plays an essential role in DN development and inhibiting EGFR may serve as a potential therapeutic strategy in diabetic kidney diseases.

Pyruvate kinase M2 activation may protect against the progression of diabetic glomerular pathology and mitochondrial dysfunction

Diabetic nephropathy (DN) is a major cause of end-stage renal disease, and therapeutic options for preventing its progression are limited. To identify novel therapeutic strategies, we studied protective factors for DN using proteomics on glomeruli from individuals with extreme duration of diabetes (ł50 years) without DN and those with histologic signs of DN. Enzymes in the glycolytic, sorbitol, methylglyoxal and mitochondrial pathways were elevated in individuals without DN. In particular, pyruvate kinase M2 (PKM2) expression and activity were upregulated. Mechanistically, we showed that hyperglycemia and diabetes decreased PKM2 tetramer formation and activity by sulfenylation in mouse glomeruli and cultured podocytes. Pkm-knockdown immortalized mouse podocytes had higher levels of toxic glucose metabolites, mitochondrial dysfunction and apoptosis. Podocyte-specific Pkm2-knockout (KO) mice with diabetes developed worse albuminuria and glomerular pathology. Conversely, we found that pharmacological activation of PKM2 by a small-molecule PKM2 activator, TEPP-46, reversed hyperglycemia-induced elevation in toxic glucose metabolites and mitochondrial dysfunction, partially by increasing glycolytic flux and PGC-1α mRNA in cultured podocytes. In intervention studies using DBA2/J and Nos3 (eNos) KO mouse models of diabetes, TEPP-46 treatment reversed metabolic abnormalities, mitochondrial dysfunction and kidney pathology. Thus, PKM2 activation may protect against DN by increasing glucose metabolic flux, inhibiting the production of toxic glucose metabolites and inducing mitochondrial biogenesis to restore mitochondrial function.

Synergistic Interaction of Hypertension and Diabetes in Promoting Kidney Injury and the Role of Endoplasmic Reticulum Stress

Diabetes mellitus and hypertension are major risk factors for chronic kidney injury, together accounting for >70% of end-stage renal disease. In this study, we assessed interactions of hypertension and diabetes mellitus in causing kidney dysfunction and injury and the role of endoplasmic reticulum (ER) stress. Hypertension was induced by aorta constriction (AC) between the renal arteries in 6-month-old male Goto-Kakizaki (GK) type 2 diabetic and control Wistar rats. Fasting plasma glucose averaged 162±11 and 87±2 mg/dL in GK and Wistar rats, respectively. AC produced hypertension in the right kidney (above AC) and near normal blood pressure in the left kidney (below AC), with both kidneys exposed to the same levels of glucose, circulating hormones, and neural influences. After 8 weeks of AC, blood pressure above the AC (and in the right kidney) increased from 109±1 to 152±5 mm Hg in GK rats and from 106±4 to 141±5 mm Hg in Wistar rats. The diabetic-hypertensive right kidneys in GK-AC rats had much greater increases in albumin excretion and histological injury compared with left kidneys (diabetes mellitus only) of GK rats or right kidneys (hypertension only) of Wistar-AC rats. Marked increases in ER stress and oxidative stress indicators were observed in diabetic-hypertensive kidneys of GK-AC rats. Inhibition of ER stress with tauroursodeoxycholic acid for 6 weeks reduced blood pressure (135±4 versus 151±4 mm Hg), albumin excretion, ER and oxidative stress, and glomerular injury, while increasing glomerular filtration rate in hypertensive-diabetic kidneys. These results suggest that diabetes mellitus and hypertension interact synergistically to promote kidney dysfunction and injury via ER stress.

Positioning of Tacrolimus for the Treatment of Diabetic Nephropathy Based on Computational Network Analysis

Objective

To evaluate tacrolimus as therapeutic option for diabetic nephropathy (DN) based on molecular profile and network-based molecular model comparisons.

Materials and Methods

We generated molecular models representing pathophysiological mechanisms of DN and tacrolimus mechanism of action (MoA) based on literature derived data and transcriptomics datasets. Shared enriched molecular pathways were identified based on both model datasets. A newly generated transcriptomics dataset studying the effect of tacrolimus on mesangial cells in vitro was added to identify mechanisms in DN pathophysiology. We searched for features in interference between the DN molecular model and the tacrolimus MoA molecular model already holding annotation evidence as diagnostic or prognostic biomarker in the context of DN.

Results

Thirty nine molecular features were shared between the DN molecular model, holding 252 molecular features and the tacrolimus MoA molecular model, holding 209 molecular features, with six additional molecular features affected by tacrolimus in mesangial cells. Significantly affected molecular pathways by both molecular model sets included cytokine-cytokine receptor interactions, adherens junctions, TGF-beta signaling, MAPK signaling, and calcium signaling. Molecular features involved in inflammation and immune response contributing to DN progression were significantly downregulated by tacrolimus (e.g. the tumor necrosis factor alpha (TNF), interleukin 4, or interleukin 10). On the other hand, pro-fibrotic stimuli being detrimental to renal function were induced by tacrolimus like the transforming growth factor beta 1 (TGFB1), endothelin 1 (EDN1), or type IV collagen alpha 1 (COL4A1).

Conclusion

Patients with DN and elevated TNF levels might benefit from tacrolimus treatment regarding maintaining GFR and reducing inflammation. TGFB1 and EDN1 are proposed as monitoring markers to assess degree of renal damage. Next to this stratification approach, the use of drug combinations consisting of tacrolimus in addition to ACE inhibitors, angiotensin receptor blockers, TGFB1- or EDN1-receptor antagonists might warrant further studies.

Presentation, pathology and prognosis of renal disease in type 2 diabetes

OBJECTIVE

Non-diabetic renal disease (NDRD) is common in patients with type 2 diabetes (T2D), but the relationship between its presentation and prognosis is unknown.

RESEARCH DESIGN AND METHODS

In a retrospective cohort study, we compared renal and patient survival among 263 patients with T2D who had native renal biopsies between 2002 and 2008 from three Auckland hospitals in New Zealand. The presence of diabetic nephropathy (DN), NDRD or mixed (DN and NDRD) was determined from biopsy. We examined clinical associations according to NDRD etiologies and mode of presentation-acute (defined by acute kidney injury (AKI)) or non-acute. Patients were followed until end-stage renal disease, death or December 2015. Survival was compared using Log-rank test.

RESULTS

94 (36%) patients had DN, 72 (27%) had NDRD, and 97 (37%) had mixed pathologies. Obesity-related focal segmental glomerulosclerosis was the most common NDRD (46%) in patients with non-acute presentations, whereas interstitial nephritis or immune-complex glomerulonephritides were the most prevalent in those with acute presentations (60%). DN was commonly associated with AKI (p<0.001). The prevalence of DN increased with diabetes duration (p<0.001), but NDRD was still found in 55% of subjects with ≥14 years T2D. NDRD was strongly associated with the absence of retinopathy (p<0.001). Renal survival was best in the NDRD group (p<0.001). Among those with DN, renal prognosis was worse in those with more advanced DN lesions and those with an acute presentation (p<0.001). The proportion of all-cause mortality was similar in all three groups, but overall survival was poorest in the DN group (p=0.025).

CONCLUSIONS

Renal disease in patients with T2D is heterogeneous. The renal prognosis differs markedly according to histopathological diagnosis and mode of presentation.

Pericytes, an overlooked player in vascular pathobiology

Pericytes are a heterogeneous population of cells located in the blood vessel wall. They were first identified in the 19th century by Rouget, however their biological role and potential for drug targeting have taken time to be recognised. Isolation of pericytes from several different tissues has allowed a better phenotypic and functional characterization. These findings revealed a tissue-specific, multi-functional group of cells with multilineage potential. Given this emerging evidence, pericytes have acquired specific roles in pathobiological events in vascular diseases. In this review article, we will provide a compelling overview of the main diseases in which pericytes are involved, from well-established mechanisms to the latest findings. Pericyte involvement in diabetes and cancer will be discussed extensively. In the last part of the article we will review therapeutic approaches for these diseases in light of the recently acquired knowledge. To unravel pericyte-related vascular pathobiological events is pivotal not only for more tailored treatments of disease but also to establish pericytes as a therapeutic tool.

Implantation of Autologous Selected Renal Cells in Diabetic Chronic Kidney Disease Stages 3 and 4-Clinical Experience of a "First in Human" Study

Introduction

Animal models of chronic kidney disease demonstrate that a redundant population of therapeutically bioactive selected renal cells (SRCs) can be delivered to the kidney through intraparenchymal injection and arrest disease progression. Direct injection of SRCs has been shown to attenuate nuclear factor-κB, which is known to drive tissue inflammation, as well as the transforming growth factor-β-mediated plasminogen activator inhibitor-1 response that drives tissue fibrosis.

Methods

We present experience from the first-in-human clinical study with SRCs. Seven male type 2 diabetic patients (63 ± 2 years of age) with chronic kidney disease stage 3 to 4 (estimated glomerular filtration rate 25 ± 2 ml/min) were recruited. After blood and urine sampling, iohexol clearance, magnetic resonance imaging, and renal scintigraphy, patients underwent ultrasound-guided renal biopsy. Two cores of renal tissue were shipped to the manufacturing plant for cell isolation, culture, and product preparation. Formulated SRCs were transported back to study sites (range 59-87 days after biopsy) for intracortical injection using a retroperitoneoscopic technique.

Results

Laparoscopically assisted implantation of SRCs was uneventful in all patients. However, postoperative complications were common and suggest that other techniques of SRC delivery should be used. Kidney volume, split function, and glomerular filtration rate did not change during 12 months of follow-up. An extended 24-month follow-up in 5 of the patients showed a decline in estimated glomerular filtration rate (cystatin C).

Discussion

Postoperative complications following retroperitoneoscopic implantation of SRC in the kidney cortex seem to be related to the surgical procedure rather than to injection of the cell product. No changes in renal function were observed during the original 12-month protocol. Beyond the first 12 months after cell implantation, individual renal function began to deteriorate during further follow-up.

Beneficial effects of urine-derived stem cells on fibrosis and apoptosis of myocardial, glomerular and bladder cells

Urine-derived stem cells (USCs) are isolated from voided urine and display high proliferative activity and multiple differentiation potentials. The applicability of USCs in the treatment of bladder dysfunction and in cell-based urological tissue engineering has been demonstrated. Whether they could serve as a potential stem cell source for the treatment of diabetes mellitus (DM) and its complications has not been investigated. Here, we report the repairing and protective effects of USCs on pancreatic islets, the myocardium, the renal glomerulus and the bladder detrusor in diabetic rat models. Type 2 diabetic rat models were induced by means of a high fat diet and intraperitoneal injection with streptozotocin. USCs isolated from voided urine were administered via tail veins. The functional changes of pancreatic islets, left ventricle, glomerulus and bladder micturition were assessed by means of insulin tolerance tests, echocardiography, urine biochemical indexes and cystometry. The histologic changes were evaluated by hematoxylin and eosin staining, Masson's trichrome staining and TUNEL staining. Treatment with USCs significantly alleviated the histological destruction and functional decline. Although the USC treatment did not decrease fasting blood glucose to a significantly different level, the fibrosis and apoptosis of the myocardium, glomerulus and detrusor were significantly inhibited. This study indicates that administration of USCs may be useful for the treatment of the complications of DM.