Increase of Th17 Cell Phenotype in Kidney Transplant Recipients with Chronic Allograft Dysfunction

This study was performed to determine the association of Th17 cell phenotype with chronic allograft dysfunction in kidney transplant recipients (KTRs). We compared the expression of Th17 cell phenotype in KTRs with chronic allograft dysfunction group (CAD, n = 52) with four control groups (long-term stable KTRs (LTS, n = 67), early stable KTRs (ES, n = 28), end stage renal disease (ESRD, n = 45), and healthy control (HC, n = 26). We also performed in vitro study using human proximal renal tubular epithelial cell line (HPRTEpiC) to evaluate the effect of IL-17 on human renal tubular epithelial cells. The CAD group showed increased percentage of Th17 cells out of CD4⁺ T cells and also increased proportion of IL-17 producing cells out of effector memory T cells or out of CCR4⁺CCR6⁺/CD4⁺ T cells compared to the LTS group and other control groups. Also, the serum level of IL-17, IL-33, and RAGE, and the expression of IL-1beta, RAGE, and HMGB1 mRNA showed an increase in the CAD group compared to the LTS group. In vitro study revealed that IL-17 increased production of IL-6 and IL-8 and up-regulated profibrotic gene expression such as ACTA-2 and CTGF in HPRTEpiC in a dose-dependent manner, which suggests that IL-17 has a role in the development of renal tubular cell injury. The results of our study may suggest that increase of Th17 cell phenotype could be a marker for the chronic allograft injury; hence there is a need to develop diagnostic and therapeutic tools targeting the Th17 cells pathway.     

Identification and Validation of Urinary Metabolite Biomarkers for Major Depressive Disorder

Major depressive disorder (MDD) is a widespread and debilitating mental disorder. However, there are no biomarkers available to aid in the diagnosis of this disorder. In this study, a nuclear magnetic resonance spectroscopy–based metabonomic approach was employed to profile urine samples from 82 first-episode drug-naïve depressed subjects and 82 healthy controls (the training set) in order to identify urinary metabolite biomarkers for MDD. Then, 44 unselected depressed subjects and 52 healthy controls (the test set) were used to independently validate the diagnostic generalizability of these biomarkers. A panel of five urinary metabolite biomarkers—malonate, formate, N-methylnicotinamide, m-hydroxyphenylacetate, and alanine—was identified. This panel was capable of distinguishing depressed subjects from healthy controls with an area under the receiver operating characteristic curve (AUC) of 0.81 in the training set. Moreover, this panel could classify blinded samples from the test set with an AUC of 0.89. These findings demonstrate that this urinary metabolite biomarker panel can aid in the future development of a urine-based diagnostic test for MDD.Major depressive disorder (MDD)¹ is a debilitating mental disorder affecting up to 15% of the general population and accounting for 12.3% of the global burden of disease (1, 2). Currently, the diagnosis of MDD still relies on the subjective identification of symptom clusters rather than empirical laboratory tests. The current diagnostic modality results in a considerable error rate (3), as the clinical presentation of MDD is highly heterogeneous and the current symptom-based method is not capable of adequately characterizing this heterogeneity (4). An approach that can be used to circumvent these limitations is to identify disease biomarkers to support objective diagnostic laboratory tests for MDD.Metabonomics, which can measure the small molecules in given biosamples such as plasma and urine without bias (5), has been extensively used to characterize the metabolic changes of diseases and thus facilitate the identification of novel disease-specific signatures as putative biomarkers (6–10). Nuclear magnetic resonance (NMR) spectroscopy–based metabonomic approaches characterized by sensitive, high-throughput molecular screening have been employed previously in identifying novel biomarkers for a variety of neuropsychiatric disorders, including stroke, bipolar disorder, and schizophrenia (11–13).Specifically with regard to MDD, several animal studies have already characterized the metabolic changes in the blood and urine (14–19). These studies provide valuable clues as to the pathophysiological mechanism of MDD. However, no study has been designed with the aim of diagnosing this disease. Recently, using an NMR-based metabonomic approach, this research group identified a unique plasma metabolic signature that enables the discrimination of MDD from healthy controls with both high sensitivity and specificity (20). These findings motivated further study on urinary diagnostic metabolite biomarkers for MDD, which would be more valuable from a clinical applicability standpoint, as urine can be more non-invasively collected. Moreover, previous studies have also demonstrated the feasibility of identifying diagnostic metabolite biomarkers of psychiatric disorders in the urine. For example, using an NMR-based metabonomics approach, Yap et al. (21) identified a unique urinary metabolite signature that clearly discriminated autism patients from healthy controls. As systemic metabolic disturbances have been observed in the urine of a depressed animal model, it is likely that diagnostic metabolite markers for MDD can be detected in human urine.Therefore, in this study, NMR spectroscopy combined with multivariate pattern recognition techniques were used to profile 82 first-episode drug-naïve MDD subjects and 82 healthy controls (the training set) in order to identify potential metabolite biomarkers for MDD. Furthermore, 44 unselected MDD subjects and 52 healthy controls (the test set) were employed to independently validate the diagnostic performance of these urinary metabolite biomarkers.     

Identification of Urinary Peptide Biomarkers Associated with Rheumatoid Arthritis

Early diagnosis and treatment of rheumatoid arthritis are associated with improved outcomes but current diagnostic tools such as rheumatoid factor or anti-citrullinated protein antibodies have shown limited sensitivity. In this pilot study we set out to establish a panel of urinary biomarkers associated with rheumatoid arthritis using capillary electrophoresis coupled to mass spectrometry. We compared the urinary proteome of 33 participants of the Scottish Early Rheumatoid Arthritis inception cohort study with 30 healthy controls and identified 292 potential rheumatoid arthritis-specific peptides. Amongst them, 39 were used to create a classifier model using support vector machine algorithms. Specific peptidic fragments were differentially excreted between groups; fragments of protein S100-A9 and gelsolin were less abundant in rheumatoid arthritis while fragments of uromodulin, complement C3 and fibrinogen were all increasingly excreted. The model generated was subsequently tested in an independent test-set of 31 samples. The classifier demonstrated a sensitivity of 88% and a specificity of 93% in diagnosing the condition, with an area under the receiver operating characteristic curve of 0.93 (p<0.0001). These preliminary results suggest that urinary biomarkers could be useful in the early diagnosis of rheumatoid arthritis. Further studies are currently being undertaken in larger cohorts of patients with rheumatoid arthritis and other athridities to assess the potential of the urinary peptide based classifier in the early detection of rheumatoid arthritis.     

Urinary Biomarkers Indicative of Apoptosis and Acute Kidney Injury in the Critically Ill

Background

Apoptosis is a key mechanism involved in ischemic acute kidney injury (AKI), but its role in septic AKI is controversial. Biomarkers indicative of apoptosis could potentially detect developing AKI prior to its clinical diagnosis.

Methods

As a part of the multicenter, observational FINNAKI study, we performed a pilot study among critically ill patients who developed AKI (n = 30) matched to critically ill patients without AKI (n = 30). We explored the urine and plasma levels of cytokeratin-18 neoepitope M30 (CK-18 M30), cell-free DNA, and heat shock protein 70 (HSP70) at intensive care unit (ICU) admission and 24h thereafter, before the clinical diagnosis of AKI defined by the Kidney Disease: Improving Global Outcomes -creatinine and urine output criteria. Furthermore, we performed a validation study in 197 consecutive patients in the FINNAKI cohort and analyzed the urine sample at ICU admission for CK-18 M30 levels.

Results

In the pilot study, the urine or plasma levels of measured biomarkers at ICU admission, at 24h, or their maximum value did not differ significantly between AKI and non-AKI patients. Among 20 AKI patients without severe sepsis, the urine CK-18 M30 levels were significantly higher at 24h (median 116.0, IQR [32.3–233.0] U/L) than among those 20 patients who did not develop AKI (46.0 [0.0–54.0] U/L), P = 0.020. Neither urine cell-free DNA nor HSP70 levels significantly differed between AKI and non-AKI patients regardless of the presence of severe sepsis. In the validation study, urine CK-18 M30 level at ICU admission was not significantly higher among patients developing AKI compared to non-AKI patients regardless of the presence of severe sepsis or CKD.

Conclusions

Our findings do not support that apoptosis detected with CK-18 M30 level would be useful in assessing the development of AKI in the critically ill. Urine HSP or cell-free DNA levels did not differ between AKI and non-AKI patients.     

Expression of the Integrin-Linked Kinase in a Rat Kidney Model of Chronic Allograft Nephropathy

The purpose of this study was to investigate the expression and significance of integrin-linked kinase (ILK) in the pathogenesis of chronic allograft nephropathy (CAN) in rats. For this, kidneys of Fisher (F344) rats were orthotopically transplanted into Lewis (LEW) rats. The animals were evaluated at 4, 8, 12, 16, and 24 weeks post-transplantation for renal function and histopathology. ILK protein expression was determined by Western-blot and immunohistological assays, and mRNA by RT-PCR. Our data show that 24-h urinary protein excretion in CAN rats increased significantly at week 16 as compared with F344/LEW controls. Allografts showed markedly increased mononuclear cells infiltration and presented with severe interstitial fibrosis and tubular atrophy at 16 and 24 weeks. ILK expression (protein/mRNA) was upregulated in rat kidneys with CAN, and the increase became more significant over time after transplantation. ILK expression correlated significantly with 24-h urinary protein excretion, serum creatinine levels, tubulointerstitial mononuclear cells infiltration, smooth muscle cells (SMCs) migration in vascular wall, and interstitial fibrosis. Therefore, it was concluded that ILK overexpression was the key event that involved mononuclear cells infiltration and vascular SMCs migration at early stage, and interstitial fibrosis and allograft nephroangiosclerosis at later stage of CAN pathogenesis in rats.     

Label-free Quantitative Urinary Proteomics Identifies the Arginase Pathway as a New Player in Congenital Obstructive Nephropathy

Obstructive nephropathy is a frequently encountered situation in newborns. In previous studies, the urinary peptidome has been analyzed for the identification of clinically useful biomarkers of obstructive nephropathy. However, the urinary proteome has not been explored yet and should allow additional insight into the pathophysiology of the disease. We have analyzed the urinary proteome of newborns (n = 5/group) with obstructive nephropathy using label free quantitative nanoLC-MS/MS allowing the identification and quantification of 970 urinary proteins. We next focused on proteins exclusively regulated in severe obstructive nephropathy and identified Arginase 1 as a potential candidate molecule involved in the development of obstructive nephropathy, located at the crossroad of pro- and antifibrotic pathways. The reduced urinary abundance of Arginase 1 in obstructive nephropathy was verified in independent clinical samples using both Western blot and MRM analysis. These data were confirmed in situ in kidneys obtained from a mouse obstructive nephropathy model. In addition, we also observed increased expression of Arginase 2 and increased total arginase activity in obstructed mouse kidneys. mRNA expression analysis of the related arginase pathways indicated that the pro-fibrotic arginase-related pathway is activated during obstructive nephropathy. Taken together we have identified a new actor in the development of obstructive nephropathy in newborns using quantitative urinary proteomics and shown its involvement in an in vivo model of disease. The present study demonstrates the relevance of such a quantitative urinary proteomics approach with clinical samples for a better understanding of the pathophysiology and for the discovery of potential therapeutic targets.Congenital obstructive nephropathy is the main cause of end stage renal disease (ESRD) in children (1). The most frequently found cause of congenital obstructive nephropathy is ureteropelvic junction (UPJ)¹ obstruction with an estimated incidence of 1 in 1000–1500 births. Milder forms of UPJ obstruction often progress to the spontaneous resolution of the pathology over time. This has led to a watchful waiting approach with surgical intervention only if renal deterioration is detected (2). Although this medical surveillance prevents unnecessary surgery, it mostly relies on invasive follow-up. Consequently with the aim to reduce this invasive follow-up, several groups have initiated research to identify noninvasive urinary biomarkers of UPJ obstruction using both targeted and nontargeted (e.g. proteome analysis based) strategies. Targeted strategies including urinary cytokine expression analyses failed to clearly determine the need for surgery in UPJ obstruction (3, 4). On the other hand, untargeted strategies have been more successful and by using urinary proteomics, biomarkers for renal and non-renal diseases have been identified (5–9). Using urinary peptidome analysis, we identified and validated a urinary peptide panel that predicted the clinical outcome of newborns with UPJ obstruction with 97% accuracy several months in advance (3, 10). An independent small-scale study confirmed the efficiency of this biomarker panel (7). These studies indicate the potential of urinary proteomics to predict the clinical fate of patients with UPJ obstruction. Although these endogenous urinary peptide biomarkers are of great potential clinical value, sequencing of these biomarkers mainly identified collagen fragments that are less informative on the pathophysiology of the disease. In contrast, studies of the high molecular weight urinary proteome (i.e. proteins) might be more informative on the pathophysiology of disease. Different approaches have been used in the past to characterize the urinary proteome, either by 2D-gel electrophoresis coupled to mass spectrometry (11, 12) or reverse phase liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis (13–16). In-depth proteome analysis using extensive fractionation of the sample and high resolution, fast sequencing mass spectrometers have reported the identification of >2000 proteins in normal human urine (13, 15, 16). Here, we applied quantitative high-resolution label free LC-MS/MS analysis for the identification of urinary proteins associated to UPJ obstruction in newborns. Among a number of proteins uniquely associated with severe UPJ obstruction, we identified Arginase 1, not previously recognized in UPJ obstruction. Using an independent larger cohort, we further verified reduced urinary abundance of Arginase 1 using both Western blot and multiple reaction monitoring (MRM). Using the mouse model of obstructive nephropathy, we observed that the expression of arginases is modulated in situ in obstructed kidneys. Further gene expression analysis of the arginase pathway allowed us to hypothesize for a role of arginases in the development of fibrotic lesions in obstructive nephropathy.     

Naturally Occurring Human Urinary Peptides for Use in Diagnosis of Chronic Kidney Disease

Because of its availability, ease of collection, and correlation with physiology and pathology, urine is an attractive source for clinical proteomics/peptidomics. However, the lack of comparable data sets from large cohorts has greatly hindered the development of clinical proteomics. Here, we report the establishment of a reproducible, high resolution method for peptidome analysis of naturally occurring human urinary peptides and proteins, ranging from 800 to 17,000 Da, using samples from 3,600 individuals analyzed by capillary electrophoresis coupled to MS. All processed data were deposited in an Structured Query Language (SQL) database. This database currently contains 5,010 relevant unique urinary peptides that serve as a pool of potential classifiers for diagnosis and monitoring of various diseases. As an example, by using this source of information, we were able to define urinary peptide biomarkers for chronic kidney diseases, allowing diagnosis of these diseases with high accuracy. Application of the chronic kidney disease-specific biomarker set to an independent test cohort in the subsequent replication phase resulted in 85.5% sensitivity and 100% specificity. These results indicate the potential usefulness of capillary electrophoresis coupled to MS for clinical applications in the analysis of naturally occurring urinary peptides.Chronic kidney disease (CKD)1 is often characterized by a slow, progressive loss of renal function with a loss of glomerular filtration over a period of months or years that may eventually lead to end stage renal disease (ESRD). Patients with ESRD require renal replacement therapy (dialysis or kidney transplantation). The most common causes of CKD in North America, Europe, and Japan are diabetic nephropathy, hypertension, and glomerulonephritis (1). Together, these diseases account for ∼75% of all adult cases of ESRD. Historically, kidney diseases were classified according to the anatomical compartment of the kidney that is involved. On this basis, vascular diseases include large and small vessel diseases, such as hypertensive nephropathy and vasculitis. Glomerular diseases comprise a diverse group of histologically defined primary glomerulopathies (e.g. focal segmental glomerulosclerosis (FSGS), membranous glomerulonephritis (MGN), minimal change disease (MCD), and IgA nephropathy (IgAN)) and secondary glomerulopathies due to diabetes mellitus (diabetic nephropathy), systemic autoimmune disorders (e.g. lupus erythematosus and hemolytic-uremic syndrome), or chronic viral infection (e.g. hepatitis and HIV). Tubular diseases are characterized by low molecular weight proteinuria and multiple transport defects (e.g. DeToni-Debré-Fanconi syndrome).In clinical practice, renal damage is generally detected by proteinuria/albuminuria on urinalysis or quantitative measurement, changes in serum creatinine concentration for estimation of glomerular filtration rate, or both. However, these methods have major limitations as they are nonspecific and frequently are also late manifestations of renal damage. Therefore, we have sought to define alternative biomarkers for renal damage that may enable earlier and more accurate disease assessment.Analysis of urine plays a central role in clinical diagnostics as it can be collected non-invasively. Urine as a body fluid for clinical analysis is relatively stable, probably due to the fact that it is “stored” for hours in the bladder; hence, proteolytic degradation by endogenous proteases may be essentially complete by the time of voiding (2). This is in sharp contrast to blood for which the activation of proteases and, consequently, generation of an array of proteolytic breakdown products are inevitably associated with its collection (3). The human urinary peptidome has been extensively investigated to gain insight about disease processes affecting the kidney and the urogenital tract (4–6). Urinary proteins and peptides originate not only from glomerular filtration but also from tubular secretion, epithelial cells shed from the kidney and urinary tract, secreted exosomes, and seminal secretions (7–9). Urine is a rich source of biomarkers for a wide range of diseases due to specific changes in its proteome (10–13). To test the feasibility of urinary proteomics as a non-invasive diagnostic tool, large scale studies are needed to analyze urine samples with reliable and quantitative experimental procedures. Various techniques have been applied to this effort, including two-dimensional electrophoresis combined with mass spectrometry (MS) and/or immunochemical identification of proteins (14–16), liquid chromatography coupled to mass spectrometry (LC-MS) (17, 18), and surface-enhanced laser desorption/ionization mass spectrometry (SELDI-MS) (19).Because of mostly technical challenges, studies relying on proteomics experimental procedures are often restricted to the comparison of two groups of subjects (i.e. healthy controls versus patients with a well defined disease entity) with only a few individuals in each group. The lack of comparability severely limits the suitability of such data for a meta-analysis approach to define broadly applicable biomarkers. Consequently, findings from several studies cannot be used to explore the human urinary proteome/peptidome in its entirety. In addition, the health state of patients with kidney disease is often too heterogeneous to be reliably classified by biomarkers identified by such a strictly single disease-oriented approach. Diagnosis of individuals with different stages or types of kidney disease (disease controls) is conceivable by multiplex screening of proteomics data. Realization of such an approach critically depends on the use of a measurement platform allowing analysis of proteomic profiles within a reasonably short time and with high resolution and on the generation of a reference database for the human urinary proteome/peptidome.Capillary electrophoresis coupled to mass spectrometry (CE-MS) enables reproducible and robust high resolution analysis of several thousand low molecular weight urinary proteins/peptides in less than an hour (5). In comparison with other proteomics methods, CE-MS offers several advantages. (i) It provides fast separation with high resolution. (ii) It is robust: capillaries are inexpensive and can be reconditioned efficiently using NaOH. (iii) It is compatible with most volatile buffers and analytes generally required for ESI. (iv) It provides a stable constant flow, avoiding the necessity of buffer gradients (for more details, see recent reviews (3, 5, 20)).This approach has recently been used to analyze urine samples from healthy individuals and patients with various chronic kidney diseases in several independent masked studies (21–27), including IgAN (28), diabetic nephropathy (29), and ANCA-associated vasculitis (30). The high number of data sets analyzed under identical conditions using the same technological platform allows comprehensive characterization of the low molecular weight proteome (peptidome) that can then become a primary source of information for the diagnosis, classification, and monitoring of a wide range of diseases. Here, we report the analysis of the human urinary peptidome by CE-MS and the identification of peptide urinary biomarkers for the detection of pathological changes in the kidney during the development of many forms of CKD. Furthermore, we have replicated these findings in an independent cohort.     

Predictive Usefulness of Urinary Biomarkers for the Identification of Cyclosporine A-Induced Nephrotoxicity in a Rat Model

The main side effect of cyclosporine A (CsA), a widely used immunosuppressive drug, is nephrotoxicity. Early detection of CsA-induced acute nephrotoxicity is essential for stop or minimize kidney injury, and timely detection of chronic nephrotoxicity is critical for halting the drug and preventing irreversible kidney injury. This study aimed to identify urinary biomarkers for the detection of CsA-induced nephrotoxicity. We allocated salt-depleted rats to receive CsA or vehicle for 7, 14 or 21 days and evaluated renal function and hemodynamics, microalbuminuria, renal macrophage infiltration, tubulointerstitial fibrosis and renal tissue and urinary biomarkers for kidney injury. Kidney injury molecule-1 (KIM-1), tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), fibronectin, neutrophil gelatinase-associated lipocalin (NGAL), TGF-β, osteopontin, and podocin were assessed in urine. TNF-α, IL-6, fibronectin, osteopontin, TGF-β, collagen IV, alpha smooth muscle actin (α -SMA) and vimentin were assessed in renal tissue. CsA caused early functional renal dysfunction and microalbuminuria, followed by macrophage infiltration and late tubulointerstitial fibrosis. Urinary TNF-α, KIM-1 and fibronectin increased in the early phase, and urinary TGF-β and osteopontin increased in the late phase of CsA nephrotoxicity. Urinary biomarkers correlated consistently with renal tissue cytokine expression. In conclusion, early increases in urinary KIM-1, TNF-α, and fibronectin and elevated microalbuminuria indicate acute CsA nephrotoxicity. Late increases in urinary osteopontin and TGF-β indicate chronic CsA nephrotoxicity. These urinary kidney injury biomarkers correlated well with the renal tissue expression of injury markers and with the temporal development of CsA nephrotoxicity.     

急性肾损伤早期诊断生物标志物研究进展

急性肾损伤(Acute kidney injury,AKI)可发生于各临床科室其临床经过常见并严重,ICU的重症患者AKI的发病率和死亡率更高。早期诊断对AKI的预后影响重大,能否找到临床实用的早期预测AKI的生物学标志物尽早采取干预措施是改善其预后的关键。本文就近年来研究的几种具有潜力的生物标志物作一综述。     

蛋白质质谱分析的无标记定量算法研究进展

作为发现疾病相关生物标志物的重要途径,定量研究已成为蛋白质组学的热点问题.随着实验方法的发展和改进,定量数据处理算法也在不断更新和完善.将现有的无标记定量方法归纳为需要/不需要鉴定结果两类方法,分析比较了两类方法的异同及优缺点,详细讨论了所涉及的主要算法,总结了一些常用的无标记定量软件及对应的网络资源.展望了无标记定量数据分析的未来研究方向.     

Identification of Novel Translational Urinary Biomarkers for Acetaminophen-Induced Acute Liver Injury Using Proteomic Profiling in Mice

Drug-induced liver injury (DILI) is the leading cause of acute liver failure. Currently, no adequate predictive biomarkers for DILI are available. This study describes a translational approach using proteomic profiling for the identification of urinary proteins related to acute liver injury induced by acetaminophen (APAP). Mice were given a single intraperitoneal dose of APAP (0–350 mg/kg bw) followed by 24 h urine collection. Doses of ≥275 mg/kg bw APAP resulted in hepatic centrilobular necrosis and significantly elevated plasma alanine aminotransferase (ALT) values (p<0.0001). Proteomic profiling resulted in the identification of 12 differentially excreted proteins in urine of mice with acute liver injury (p<0.001), including superoxide dismutase 1 (SOD1), carbonic anhydrase 3 (CA3) and calmodulin (CaM), as novel biomarkers for APAP-induced liver injury. Urinary levels of SOD1 and CA3 increased with rising plasma ALT levels, but urinary CaM was already present in mice treated with high dose of APAP without elevated plasma ALT levels. Importantly, we showed in human urine after APAP intoxication the presence of SOD1 and CA3, whereas both proteins were absent in control urine samples. Urinary concentrations of CaM were significantly increased and correlated well with plasma APAP concentrations (r = 0.97; p<0.0001) in human APAP intoxicants, who did not present with elevated plasma ALT levels. In conclusion, using this urinary proteomics approach we demonstrate CA3, SOD1 and, most importantly, CaM as potential human biomarkers for APAP-induced liver injury.     

非透析慢性肾脏病患者心脏功能生物标记物的临床价值比较

目的:比较非透析慢性肾脏病患者心脏功能生物标记物的临床应用价值。方法:选取122例非透析且无急性冠脉综合征(ACS)的慢性肾脏病患者(CKD),将其分为CKD1-2期组、CKD3-4期组和CKD5期组,同时选择同期确诊急性冠脉综合征的慢性肾脏病患者20例作为对照组,观察并比较各组患者室间隔厚度(IVST)、左室后壁厚度(LVPWT),检测血液中血肌酐(Scr)、尿素氮(BUN)、心型脂肪酸结合蛋白(HFABP)、心肌钙蛋白(cTnI)以及肌酸激酶同功酶(CK-MB)。结果:非ACS的CKD患者HFABP、cTnI、CK-MB水平均呈不同程度增高,且各CKD组中这三个指标的阳性率存在显著差异,其中HFABP阳性率最高(P0.05)。cTnI与e GFR、Scr及年龄无显著相关性(P0.05),但与IVST、LVPWT呈显著正相关(P0.05);CK-MB与e GFR、Scr、年龄、IVST、LVPWT均无相关性(P0.05);HFABP与e GFR呈负相关(P0.05),与Scr和BUN正相关(P0.05),与年龄、IVST、LVPWT无相关性(P0.05)。结论:在非ACS的CKD患者中,HFABP可能不是一个可靠的反映心脏功能的生物标记物,cTnI及CK-MB对于CKD患者而言是较为可靠的心脏标记物。     

Alterations of Hepatic Metabolism in Chronic Kidney Disease via D-box-binding Protein Aggravate the Renal Dysfunction

Chronic kidney disease (CKD) is associated with an increase in serum retinol; however, the underlying mechanisms of this disorder are poorly characterized. Here, we found that the alteration of hepatic metabolism induced the accumulation of serum retinol in 5/6 nephrectomy (5/6Nx) mice. The liver is the major organ responsible for retinol metabolism; accordingly, microarray analysis revealed that the hepatic expression of most CYP genes was changed in 5/6Nx mice. In addition, D-box-binding protein (DBP), which controls the expression of several CYP genes, was significantly decreased in these mice. Cyp3a11 and Cyp26a1, encoding key proteins in retinol metabolism, showed the greatest decrease in expression in 5/6Nx mice, a process mediated by the decreased expression of DBP. Furthermore, an increase of plasma transforming growth factor-β1 (TGF-β1) in 5/6Nx mice led to the decreased expression of the Dbp gene. Consistent with these findings, the alterations of retinol metabolism and renal dysfunction in 5/6Nx mice were ameliorated by administration of an anti-TGF-β1 antibody. We also show that the accumulation of serum retinol induced renal apoptosis in 5/6Nx mice fed a normal diet, whereas renal dysfunction was reduced in mice fed a retinol-free diet. These findings indicate that constitutive Dbp expression plays an important role in mediating hepatic dysfunction under CKD. Thus, the aggravation of renal dysfunction in patients with CKD might be prevented by a recovery of hepatic function, potentially through therapies targeting DBP and retinol.     

Urinary MicroRNA-10a and MicroRNA-30d Serve as Novel,Sensitive and Specific Biomarkers for Kidney Injury

The steadily increasing incidence of kidney injury is a significant threat to human health. The current tools available for the early detection of kidney injury, however, have limited sensitivity or specificity. Thus, the development of novel biomarkers to detect early kidney injury is of high importance. Employing mouse renal ischemia-reperfusion and streptozotocin (STZ)-induced renal injury as acute and chronic kidney injury model, respectively, we assessed the alteration of microRNA (miRNA) in mouse urine, serum and kidney tissue by TaqMan probe-based qRT-PCR assay. Our results demonstrated that kidney-enriched microRNA-10a (miR-10a) and microRNA-30d (miR-30d) were readily detected in mouse urine and the levels of urinary miR-10a and miR-30d were positively correlated with the degree of kidney injury induced by renal ischemia-reperfusion or STZ diabetes. In contrast, no such alteration of miR-10a and miR-30d levels was observed in mouse serum after kidney injury. Compared with the blood urea nitrogen (BUN) assay, the test for urinary miR-10a and miR-30d levels was more sensitive for the detection of acute kidney injury. Furthermore, the substantial elevation of the urinary miR-10a and miR-30d levels was also observed in focal segmental glomerulosclerosis (FSGS) patients compared to healthy donors. In conclusion, the present study collectively demonstrates that urinary miR-10a and miR-30d represent a novel noninvasive, sensitive, specific and potentially high-throughput method for detecting renal injury.     

Identification of Salivary Biomarkers for Oral Cancer Detection with Untargeted and Targeted Quantitative Proteomics Approaches

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Highlights

• •iTRAQ-based analysis of saliva samples from oral cancer patients.
• •Proteome profiling of saliva samples from patients with oral premalignant lesions.
• •Verification of salivary biomarker candidates with MRM-MS and immunoassays.
• •Identification of salivary proteins as potential biomarkers of oral cancer.

     

Urinary Uromodulin Excretion Predicts Progression of Chronic Kidney Disease Resulting from IgA Nephropathy

Background

Uromodulin, or Tamm-Horsfall protein, is the most abundant urinary protein in healthy individuals. Recent studies have suggested that uromodulin may play a role in chronic kidney diseases. We examined an IgA nephropathy cohort to determine whether uromodulin plays a role in the progression of IgA nephropathy.

Methods

A total of 344 IgA nephropathy patients were involved in this study. Morphological changes were evaluated with the Oxford classification of IgA nephropathy. Enzyme Linked Immunosorbent Assay (ELISA) measured the urinary uromodulin level on the renal biopsy day. Follow up was done regularly on 185 patients. Time-average blood pressure, time-average proteinuria, estimated glomerular filtration rate (eGFR) and eGFR decline rate were caculated. Association between the urinary uromodulin level and the eGFR decline rate was analyzed with SPSS 13.0.

Results

We found that lower baseline urinary uromodulin levels (P = 0.03) and higher time-average proteinuria (P = 0.04) were risk factors for rapid eGFR decline in a follow-up subgroup of the IgA nephropathy cohort. Urinary uromodulin level was correlated with tubulointerstitial lesions (P = 0.016). Patients that had more tubular atrophy/interstitial fibrosis on the surface had lower urinary uromodulin levels (P = 0.02).

Conclusions

Urinary uromodulin level is associated with interstitial fibrosis/tubular atrophy and contributes to eGFR decline in IgA nephropathy.