Distinct Metabolic Profile of Primary Focal Segmental Glomerulosclerosis Revealed by NMR-Based Metabolomics

Background

Primary focal segmental glomerulosclerosis (FSGS) is pathological entity which is characterized by idiopathic steroid-resistant nephrotic syndrome (SRNS) and progression to end-stage renal disease (ESRD) in the majority of affected individuals. Currently, there is no practical noninvasive technique to predict different pathological types of glomerulopathies. In this study, the role of urinary metabolomics in the diagnosis and pathogenesis of FSGS was investigated.

Methods

NMR-based metabolomics was applied for the urinary metabolic profile in the patients with FSGS (n = 25), membranous nephropathy (MN, n = 24), minimal change disease (MCD, n = 14) and IgA nephropathy (IgAN, n = 26), and healthy controls (CON, n = 35). The acquired data were analyzed using principal component analysis (PCA) followed by orthogonal projections to latent structure discriminant analysis (OPLS-DA). Model validity was verified using permutation tests.

Results

FSGS patients were clearly distinguished from healthy controls and other three types of glomerulopathies with good sensitivity and specificity based on their global urinary metabolic profiles. In FSGS patients, urinary levels of glucose, dimethylamine and trimethylamine increased compared with healthy controls, while pyruvate, valine, hippurate, isoleucine, phenylacetylglycine, citrate, tyrosine, 3-methylhistidine and β-hydroxyisovalerate decreased. Additionally, FSGS patients had lower urine N-methylnicotinamide levels compared with other glomerulopathies.

Conclusions

NMR-based metabonomic approach is amenable for the noninvasive diagnosis and differential diagnosis of FSGS as well as other glomerulopathies, and it could indicate the possible mechanisms of primary FSGS.     

The cellular signature of urinary immune cells in Lupus nephritis: new insights into potential biomarkers

IntroductionUrinary T cells represent a reliable noninvasive biomarker for proliferative Lupus nephritis (LN). Little is known about the presence of T cell subsets, B cells and macrophages in the urine although they may further improve the validity of urinary cellular biomarkers for LN.MethodsWe analyzed contemporaneous blood and urine samples of patients with active LN (n = 19), other Systemic Lupus Erythematosus (SLE) patients (n = 79) and urine samples of patients with diabetic nephropathy (DN; n = 14) and anti-neutrophil cytoplasmatic antibody (ANCA) associated vasculitis (AAV; n = 11) by flow cytometry.ResultsNumbers of urinary T cells, B cells and macrophages correlated with disease activity and were significantly higher in the active LN group. Urinary T cells showed excellent distinction of patients with active LN, CD8+ T cells (AUC of ROC = 1.000) and CD4+ T cells (AUC = 0.9969) alike. CD19+ B cells (AUC = 0.7823) and CD14+ macrophages (AUC = 0.9066), as well as the clinical standard proteinuria (AUC = 0.9201), failed to reach these high standards. Patients with DN or AAV also showed increased urinary cell counts, although the CD4/CD8-ratio was significantly lower in SLE compared to in DN (p = 0.0006). Urinary CD4+ T cells of active LN patients proved to be mainly of effector memory phenotype and expressed significantly more CD40L and ki67 than corresponding blood cells. Urinary Treg counts correlated with disease activity.ConclusionsDespite of detectable urinary cell counts for B cells and macrophages, T cells remain the best urinary cellular biomarker for LN. A low CD4/CD8-ratio seems to be characteristic for LN.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0600-y) contains supplementary material, which is available to authorized users.     

Urinary Xist is a potential biomarker for membranous nephropathy

Membranous nephropathy (MN), a type of glomerular nephritis, is the most common cause of nephrotic syndrome in human adults. Changes in gene expression as a result of epigenetic dysregulation through long noncoding RNAs (lncRNAs) are increasingly being recognized as important factors in disease. Using an experimental MN mouse model, we identify the first dysregulated lncRNAs, Xist and NEAT1, whose levels are significantly upregulated in both tubular epithelial and glomerular cells. MN is also often characterized by glomerular podocyte injury. Treatment of a mouse podocyte cell line with lipopolysaccharides to induce injury resulted in the stable elevation of Xist, but not NEAT1 levels. In mice, the observed changes in Xist levels are specific: Xist can be effectively detected in urine, with a strong correlation to disease severity, but not serum in MN samples. We find that regulation of Xist may be controlled by post-translational modifications. H3K27me3 levels are significantly downregulated in mouse MN kidney, where chromatin immunoprecipitation experiments also showed decreased H3K27me3 at Xist promoter regions. Finally, we show that our findings in mice can be extended to human clinical samples. Urinary Xist is significantly elevated in urine samples from patients with different types of glomerular nephritis, including MN, compared to normal counterparts. Together, our results suggest that a reduction of H3K27me3 at Xist promoter regions leads to elevated levels of urinary Xist, which may be used as a biomarker to detect MN.     

Genetic diversity of the apolipoprotein E gene and diabetic nephropathy: a meta-analysis

In the past decade, a number of case–control studies have been carried out to investigate the relationship between the ApoE polymorphism and diabetic nephropathy. However, the results have been inconclusive. To investigate this inconsistency, we performed a meta-analysis of all available studies dealing with the relationship between the ApoE polymorphism and DN. The 23 studies in the meta- analysis included 6,012 diabetic patients with (n = 2,979) and without (n = 3,033) DN. The ApoE ε2 allele was significantly associated with DN (OR = 1.64, 95% CI: 1.26–2.13; P(Z) = 0.00027), whereas the ε4 allele was non-significantly associated with DN (OR = 0.93, 95% CI: 0.78–1.11; P(Z) = 0.418). However, significant heterogeneity was detected. In further subgroup analyses, genotyping methods, outcome of cases and duration of diabetes in controls were found to explain some of the heterogeneity. Genotypic analysis also found a strong association between the ε2 carriers and DN (OR = 1.61, 95% CI: 1.22–2.13; P(Z) = 0.001) and indicated that ε4 tended to have a marginally significant protective effect for DN (OR = 0.82, 95% CI: 0.65–1.03; P(Z) = 0.085). The results of our meta-analysis support a genetic association between the ApoE polymorphism and DN. ε2 increases the risk of DN in diabetes patients, while ε4 trends to be protective. These findings may have implications for therapeutic intervention in diabetic nephropathy.     

Clinical significance of plasma CD146 and P-selectin in patients with type 2 diabetic nephropathy

Objective

To investigate the levels of plasma CD146 and P-selectin in patients with type 2 diabetic nephropathy at different stages.

Methods

A total of 80 patients with type 2 diabetes mellitus were enrolled in the present study. According to 24 h urinary albumin excretion ratio and renal function, they were further divided into group of diabetes without microalbuminuria (DN0, n = 20), microalbuminuria group (DN1, n = 20), macroalbuminuria group (DN2, n = 20) and renal insufficiency group (DN3, n = 20). Another 20 healthy subjects were enrolled as control group (non-DM). Plasma CD146 and P-selectin were measured by ELISA.

Results

Plasma CD146 and P-selectin were significantly increased in patients with type 2 diabetes with microalbuminuria (DN1) compared with health control (CD146: 415.3 ± 29.0 vs. 243.5 ± 14.7 ng/ml, P < 0.05; P-selectin: 66.8 ± 3.4 vs. 45.3 ± 2.7 ng/ml, P < 0.001). With the development of diabetic nephropathy, both plasma CD146 and P-selectin level progressively rise, with the highest levels in patients with significant renal insufficiency (DN3: 515.9 ± 36.9 and 81.5 ± 5.1 ng/ml respectively, P < 0.001). Moreover, the increase in CD146 is positively co-related to the rise of P-selectin in patients with type 2 diabetes.

Conclusion

Expression of CD146 and P-selectin in patients with type 2 diabetes is elevated, and they are positively correlated with severity of diabetic nephropathy.     

Wilm's Tumor-1 Protein Levels in Urinary Exosomes from Diabetic Patients with or without Proteinuria

Background

Podocyte injury is an early feature of diabetic nephropathy (DN). Recently, urinary exosomal Wilm''s tumor-1 protein (WT1), shed by renal epithelial cells, has been proposed as a novel biomarker for podocyte injury. However, its usefulness as biomarker for early diabetic nephropathy has not been verified yet. We investigated urinary exosomal WT1 in type-1 diabetic patients to confirm its role as a non-invasive biomarker for predicting early renal function decline.

Methods

The expression of WT1 protein in urinary exosomes from spot urine samples of type-1 diabetes mellitus patients (n = 48) and healthy controls (n = 25) were analyzed. Patients were divided based on their urinary albumin excretion, ACR (mg/g creatinine) into non- proteinuria group (ACR<30 mg/g, n = 30) and proteinuria group (ACR>30 mg/g, n = 18). Regression analysis was used to assess the association between urinary exosomal levels of WT1 with parameters for renal function. Receiver Operating Characteristic (ROC) curve analysis was used to determine the diagnostic performance of exosomal WT-1.

Results

WT1 protein was detected in 33 out of 48 diabetic patients and in only 1 healthy control. The levels of urinary exosomal WT1 protein is significantly higher (p = 0.001) in patients with proteinuria than in those without proteinuria. In addition, all the patients with proteinuria but only half of the patients without proteinuria were positive for exosomal WT1. We found that the level of exosomal WT1 were associated with a significant increase in urine protein-to-creatinine ratio, albumin-to-creatinine ratio, and serum creatinine as well as a decline in eGFR. Furthermore, patients exhibiting WT1-positive urinary exosomes had decreased renal function compared to WT1-negative patients. ROC analysis shows that WT-1 effectively predict GFR<60 ml. min-1/1.73 m².

Conclusion

The predominant presence of WT1 protein in urinary exosomes of diabetic patients and increase in its expression level with decline in renal function suggest that it could be useful as early non-invasive marker for diabetic nephropathy.     

Urinary podocyte-associated mRNA profile in various stages of diabetic nephropathy

Background

Podocyte injury and subsequent excretion in urine play a crucial role in the pathogenesis and progression of diabetic nephropathy (DN). Quantification of messenger RNA (mRNA) expression in urinary sediment by real-time PCR is emerging as a noninvasive method of screening DN-associated biomarkers. We hypothesized that the urinary mRNA profile of podocyte-associated molecules may provide important clinical insight into the different stages of diabetic nephropathy.

Methods

DN patients (N = 51) and healthy controls (N = 13) were enrolled in this study. DN patients were divided into a normoalbuminuria group (UAE<30 mg/g, n = 17), a microalbuminuria group (UAE 30∼300 mg/g, n = 15), and a macroalbuminuria group (UAE>300 mg/g, n = 19), according to their urinary albumin excretion (UAE). Relative mRNA abundance of synaptopodin, podocalyxin, CD2-AP, α-actin4, and podocin were quantified, and correlations between target mRNAs and clinical parameters were examined.

Results

The urinary mRNA levels of all genes studied were significantly higher in the DN group compared with controls (p<0.05), and mRNA levels increased with DN progression. Urinary mRNA levels of all target genes positively correlated with both UAE and BUN. The expression of podocalyxin, CD2-AP, α-actin4, and podocin mRNA correlated with serum creatinine (r = 0.457, p = 0.001; r = 0.329, p = 0.01; r = 0.286, p = 0.021; r = 0.357, p = 0.006, respectively). Furthermore, podocalyxin mRNA was found to negatively correlate with eGFR (r = −0.349, p = 0.01).

Conclusion

The urinary mRNA profiles of synaptopodin, podocalyxin, CD2-AP, α-actin4, and podocin were found to increase with the progression of DN, which suggested that quantification of podocyte-associated molecules will be useful biomarkers of DN.     

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.     

Nine hub genes as the potential indicator for the clinical outcome of diabetic nephropathy

Diabetic nephropathy (DN) is one of the most serious and dangerous chronic complications caused by diabetes mellitus, and the identification and development of novel biomarkers could be beneficial for the diagnosis and prognosis of DN patients. This study focused on researching the differently expressed pattern of the DN samples from glomeruli and tubulointerstitium. Significance analysis of microarrays (SAM) was used to identify differentially regulated genes in 44 microdissected human kidney samples. Functional enrichment analysis was used to analyze the functions these genes are mostly enriched in. Besides, protein–protein interaction (PPI) network was used to select the hub genes that were associated with DN. The gene expression pattern of DN samples from glomeruli and tubulointerstitium was found to be quite different. It showed that the recurrence rate of DN originating from glomeruli and control samples was lower than that from tubulointerstitium and control samples. A total of 332 differentially expressed genes were identified between glomeruli tissues and tubulointerstitium tissues. PPI network analysis was performed on these 332 genes. Finally, nine hub genes were selected as the most potential biomarkers in the occurrence of DN. In conclusion, a total of 332 genes were found to be related to DN, and these genes were found to be mostly enriched in pathways such as immunity, inflammatory, and vascular pathways. Three genes VAV1, LCK, and Plk had the potential to serve as indicators for the occurrence and development of DN in clinical management.     

阿霉素肾病小鼠的肾脏病理转变过程

目的观察不同时间点阿霉素肾病小鼠肾脏病理的转变过程。方法 48只雄性BALB/c小鼠,随机分成对照组和模型组,模型组经尾静脉一次性注射阿霉素10.5mg/kg,对照组给予等量的生理盐水。动态观察实验12周内小鼠24 h尿蛋白、血清生化指标、肾脏病理改变。结果模型小鼠蛋白尿于实验第2周出现,持续至第12周,第8周出现高峰(均P0.05);低蛋白血症、高脂血症分别于实验第4、8周出现,血肌酐于实验第12周明显高于正常组(均P0.05)。模型小鼠肾脏病理改变第4周表现为微小病变型;第8周病变较第4周加重,硬化不明显;第12周出现肾小球局灶节段性硬化、肾小球硬化指数(GSI)为(2.81±0.84)%,明显高于同一观测时间点对照组GSI(0.33±0.21)%(P0.01)。结论一次性尾静脉注射10.5 mg/kg阿霉素,能成功复制阿霉素肾病小鼠模型,该模型在早期表现为微小病变型肾病,晚期转变为局灶性节段性肾小球硬化。     

IgA肾病与膜性肾病患者肠道微生物菌群结构分析

【背景】越来越多的证据表明肠道失衡与免疫介导的疾病相关,但肠道菌群和免疫介导的肾脏疾病之间的关系仍不清楚。【目的】通过Illumina高通量测序方法对IgA肾病(immunoglobulin A nephropathy, IgAN)、膜性肾病(membranous nephropathy, MN)患者和健康人群的肠道菌群进行比较。【方法】回顾性选择2020年9月–2021年12月期间,在甘肃省人民医院肾内科行肾穿刺活检并诊断为IgAN及MN患者的新鲜粪便标本,分别编号为IgAN组和MN组,收集体检中心健康人群粪便标本作为健康对照组,每组样本为10例。采用高通量测序技术对粪便样本中所有细菌的16S rRNA基因V3-V4区进行DNA测序,然后进行分类操作单元(operational taxonomic units, OTU)、物种分类、α多样性、β多样性等分析,比较3组之间的肠道菌群差异。【结果】与健康对照组相比,门水平上IgAN组的变形菌门(Proteobacteria)和放线菌门(Actinobacteria)比例明显增高,分别为18%vs. 4%和18.3%vs. 5%;属水平上I...     

MicroRNA-21 protects from mesangial cell proliferation induced by diabetic nephropathy in db/db mice

Diabetic nephropathy (DN) is a major diabetic complication. But the initiating molecular events triggering DN are unknown. Recent researches have addressed the role of microRNAs in diabetes and its complications. In this study, we looked for microRNAs expression during early DN, and showed microRNA-21 (miR-21) expression was downregulated in response to early DN in vitro and in vivo. Over-expression of miR-21 inhibited proliferation of mesangial cells and decreased the 24-h urine albumin excretion rate in diabetic db/db mice. Moreover, we identified PTEN as a target of miR-21. We also found PI3 K and p-Akt increased in miR-21 treated mesangial cells and db/db mice. Overall, these studies for the first time provide evidence for the potential role of miR-21 in early DN.     

Effects of physical activity on the progression of diabetic nephropathy: a meta-analysis

Background: Diabetic nephropathy (DN) is an important microvascular complication of diabetes. Physical activity (PA) is part of a healthy lifestyle for diabetic patients; however, the role of PA in DN has not been clarified. Our aim was to conduct a meta-analysis to explore the association between PA and DN risk.Methods: PubMed, Embase, Cochrane Library and Web of Science were systematically searched for articles examining PA in diabetic patients and its effect on renal function. Standardized mean differences (SMDs) and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. The study protocol is registered with PROSPERO (CRD42020191379).Results: A total of 38991 participants were identified from 18 studies. The results indicated that PA was associated with increases in the glomerular filtration rate (SMD = 0.01, 95% CI = [0.02–0.17]) and decreases in the urinary albumin creatinine ratio (SMD = −0.53, 95% CI: −0.72 to −0.34), rate of microalbuminuria (OR = 0.61, 95% CI = [0.46–0.81]), rate of acute kidney injury (OR = 0.02, 95% CI = [0.01–0.04]), rate of renal failure (OR = 0.71, 95% CI = [0.52–0.97]) and risk of DN in patients with Type 1 diabetes (OR = 0.67, 95% CI = [0.51–0.89]).Conclusions: This meta-analysis indicated that PA is effective for improving DN and slowing its progression; however, more high-quality randomized controlled trials are required on this topic.     

Comparative analysis of diabetic nephropathy and non-diabetic nephropathy disease

ObjectiveClinical symptoms of diabetic nephropathy patients and non-diabetic nephropathy are compared and analyzed, hemodialysis effect and quality of life of two kinds of nephrotic patients are analyzed.MethodsRespectively extract 1300 cases of diabetic nephropathy and non-diabetic nephropathy patients admitted to different hospitals during December 2011-December 2014. Based on whether the patient suffers from diabetes, they were divided into diabetic group and control group. Hemodialysis of two groups of patients were followed up to observe effectiveness of blood treatment, and complications were observed after one year of follow-up.ResultsHematodialysis effectiveness of diabetic nephropathy patients is significantly lower than that of non-diabetic nephropathy group. After 1 year’s follow-up, it can be found that survival rate of diabetic nephropathy patients is much lower than that of control group. In statistical comparison of data involved in the two groups of patients, P < 0.05, the difference is statistically significant.ConclusionTreatment effect of diabetic nephropathy patients is relatively poor compared to that of non-diabetic patients. In clinics, management and prevention of diabetic patients should be strengthened to avoid complication of nephropathy which brings serious injury to patients.     

Multicentric validation of proteomic biomarkers in urine specific for diabetic nephropathy

Background

Urine proteome analysis is rapidly emerging as a tool for diagnosis and prognosis in disease states. For diagnosis of diabetic nephropathy (DN), urinary proteome analysis was successfully applied in a pilot study. The validity of the previously established proteomic biomarkers with respect to the diagnostic and prognostic potential was assessed on a separate set of patients recruited at three different European centers. In this case-control study of 148 Caucasian patients with diabetes mellitus type 2 and duration ≥5 years, cases of DN were defined as albuminuria >300 mg/d and diabetic retinopathy (n = 66). Controls were matched for gender and diabetes duration (n = 82).

Methodology/Principal Findings

Proteome analysis was performed blinded using high-resolution capillary electrophoresis coupled with mass spectrometry (CE-MS). Data were evaluated employing the previously developed model for DN. Upon unblinding, the model for DN showed 93.8% sensitivity and 91.4% specificity, with an AUC of 0.948 (95% CI 0.898-0.978). Of 65 previously identified peptides, 60 were significantly different between cases and controls of this study. In <10% of cases and controls classification by proteome analysis not entirely resulted in the expected clinical outcome. Analysis of patient''s subsequent clinical course revealed later progression to DN in some of the false positive classified DN control patients.

Conclusions

These data provide the first independent confirmation that profiling of the urinary proteome by CE-MS can adequately identify subjects with DN, supporting the generalizability of this approach. The data further establish urinary collagen fragments as biomarkers for diabetes-induced renal damage that may serve as earlier and more specific biomarkers than the currently used urinary albumin.     

The potential role of the gut microbiota in modulating renal function in experimental diabetic nephropathy murine models established in same environment

Recent studies have shown that laboratory murine autoimmunity models under the same environment display different outcomes. We established diabetic nephropathy model mice under the same environment using the classic streptozotocin method. Renal dysfunction was different among the mice. Proteinuria was more significant in the severe proteinuria group (SP) than in the mild proteinuria group (MP). We hypothesized a role for the gut microbiota in the outcome and reproducibility of induced DN models. 16S rDNA gene sequencing technology was used to analyze the differences in the gut microbiota between the two groups. Here, through fecal microbiota transplantation (FMT) and gas chromatography mass spectrometry (GC–MS), we verified the role of the gut microbiota and its short-chain fatty acid (SCFA) generation in DN mouse renal dysfunction. In the SP group, there was a reduced abundance of Firmicutes (P < 0.0001), and the dominant genus Allobaculum [linear discriminant analysis (LDA) >3, P < 0.05] was positively correlated with body weight (Rho = 0.767, P < 0.01) and blood glucose content (Rho = 0.648, P < 0.05), while the dominant genus Anaerosporobacter (LDA > 3, P < 0.05) was positively correlated with 24-hour urinary protein content (Rho = 0.773, P < 0.01). In the MP group, the dominant genus Blautia (LDA > 3, P < 0.05) was negatively correlated with 24-hour urinary protein content (Rho = −0.829, P < 0.05). The results indicated that Allobaculum and Anaerosporobacter may worsen renal function, while Blautia may be a protective factor in DN. These findings suggested that the gut microbiota may contribute to the heterogeneity of the induced response since we observed potential disease-associated microbial taxonomies and correlations with DN.     

Different expression of Fibrinopeptide A and related fragments in serum of type 1 diabetic patients with nephropathy

Type 1 diabetes (insulin-dependent diabetes mellitus, IDDM) is an autoimmune disease affecting about 0.12% of the world's population. Diabetic nephropathy (DN) is a major long-term complication of both types of diabetes and retains a high human, social and economic cost. Thus, the identification of markers for the early detection of DN represents a relevant target of diabetic research.The present work is a pilot study focused on proteomic analysis of serum of controls (n = 9), IDDM patients (n = 10) and DN patients (n = 4) by the ClinProt profiling technology based on mass spectrometry. This approach allowed to identify a pattern of peptides able to differentiate the studied populations with sensitivity and specificity close to 100%. Variance of the results allowed to estimate the sample size needed to keep the expected False Discovery Rate low. Moreover, three peptides differentially expressed in the serum of patients as compared to controls were identified by LC-ESI MS/MS as the whole fibrinopeptide A peptide and two of its fragments, respectively. The two fragments were under-expressed in diabetic patients, while Fibrinopeptide A was over-expressed, suggesting that anomalous turnover of Fibrinopeptide A could be involved in the pathogenesis of DN.     

A meta-analysis of three polymorphisms in the endothelial nitric oxide synthase gene (NOS3) and their effect on the risk of diabetic nephropathy

A number of association studies have investigated the role of the nitric oxide synthase 3 (NOS3) gene in the development of diabetic nephropathy (DN). However, results have been inconclusive, largely because the studies have focused on a variety of different polymorphisms and generate inconsistent results. We performed a meta-analysis of 28 association studies focusing on three polymorphisms in the NOS3 gene (G894T (Glu289Asp), 4b/a, and T-786C) and the risk of DN published before July 2009, covering a total of 10,364 subjects. Although significant heterogeneity was initially found in the analysis of G894T, it did not remain when analysis was done by ethnic subgroups. 894T was negatively associated with DN in Caucasian populations of European origin (OR = 0.896, 0.817–0.983, 95% CI), but was positively associated with DN in East Asian (OR = 2.02, 1.20–3.42, 95% CI) and other populations. Association of the 4b/a variant was observed when studies involving microalbuminuria were excluded (OR = 1.19, 1.02–1.39, 95% CI). The T-786C variant showed an overall weak association (OR = 1.16, 1.01–1.34, 95% CI) with little heterogeneity. In summary, our meta-analysis of the effect of NOS3 gene polymorphisms on the risk of DN supports the involvement of the NOS3 gene in the pathogenesis of DN.     

Urinary proteome profiling using microfluidic technology on a chip

Clinical diagnostics and biomarker discovery are the major focuses of current clinical proteomics. In the present study, we applied microfluidic technology on a chip for proteome profiling of human urine from 31 normal healthy individuals (15 males and 16 females), 6 patients with diabetic nephropathy (DN), and 4 patients with IgA nephropathy (IgAN). Using only 4 microL of untreated urine, automated separation of proteins/peptides was achieved, and 1-7 (3.8 +/- 0.3) spectra/bands of urinary proteins/peptides were observed in the normal urine, whereas 8-16 (11.3 +/- 1.2) and 9-14 (10.8 +/- 1.2) spectra were observed in urine samples of DN and IgAN, respectively. Coefficient of variations of amplitudes of lower marker (1.2 kDa), system spectra (6-8 kDa), and upper marker (260.0 kDa) were 22.84, 24.92, and 32.65%, respectively. ANOVA with Tukey post-hoc multiple comparisons revealed 9 spectra of which amplitudes significantly differed between normal and DN urine (DN/normal amplitude ratios ranged from 2.9 to 3102.7). Moreover, the results also showed that 3 spectra (with molecular masses of 12-15, 27-28, and 34-35 kDa) were significantly different between DN and IgAN urine (DN/IgAN amplitude ratios ranged from 3.9 to 7.4). In addition to the spectral amplitudes, frequencies of some spectra could differentiate the normal from the diseased urine but could not distinguish between DN and IgAN. There was no significant difference, regarding the spectral amplitude or frequency, observed between males and females. These data indicate that the microfluidic chip technology is applicable for urinary proteome profiling with potential uses in clinical diagnostics and biomarker discovery.     

Bone‐marrow mesenchymal stem cell transplantation to treat diabetic nephropathy in tree shrews

Diabetic nephropathy (DN) is a common microvascular complication of diabetes. We used a new DN model in tree shrews to validate the use of bone‐marrow mesenchymal stem cell (BM‐MSC) transplantation to treat DN. The DN tree shrew model was established by a high‐sugar and high‐fat diet and four injections of streptozotocin. 4',6‐Diamidino‐2‐phenylindole labelled BM‐MSCs were injected into tree shrews. The DN tree shrew model was successfully established. Blood glucose was significantly increased ( p < 0.01) during the entire experiment. DN tree shrews showed dyslipidemia, insulin resistance and increased 24‐h proteinuria. At 21 days after BM‐MSC transplantation, glucose and levels of triglycerides, total cholesterol and 24‐h urine volume were lower than in tree shrews with DN alone ( p < 0.01) but were still higher than control values ( p < 0.01). Levels of creatinine and urea nitrogen as well as 24‐h proteinuria were lower for DN tree shrews with BM‐MSCs transplantation than DN alone ( p < 0.05). High‐sugar and high‐fat diet combined with STZ injection can induce a tree shrew model of DN. BM‐MSCs injection can home to damaged kidneys and pancreas, for reduced 24‐h proteinuria and improved insulin resistance. Copyright © 2014 John Wiley & Sons, Ltd.