Association between Sumoylation-Related Gene rs77447679 Polymorphism and Risk of Gastric Cancer (GC) in a Chinese Population

Purpose: Sumoylation plays a critical role in gene regulation and tumorigenesis, and is hypothesized to correlate with the development of various cancers. So far, there has been no reported association between sumoylation-related genes and the risk of gastric cancer (GC).

Methods: A total of 17 tagging single-nucleotide polymorphisms (tag-SNPs) in 5 sumoylation-related genes were selected and genotyped by SNaPshot in a case-control study, including 1021 GC patients and 1304 controls. Odds ratio (OR) and 95% confidential interval (CI) were computed to evaluate the genetic association of the onset of GC.

Results: We demonstrated that CBX4 rs77447679 polymorphism was significantly associated with GC risk (P= 0.017; adjusted OR: 1.71; 95% CI: 1.10-2.66). The patients with CC genotype had a lower risk of GC (CC vs. CA+AA, P= 0.017; adjusted OR: 1.24; 95% CI: 1.04-1.49).

Conclusion: This study revealed that CBX4 rs77447679 polymorphism was positively associated with GC, and individuals with CC genotype had less risk of GC. The risky effects and functional effect of this polymorphism in GC require further investigation.

Assessment of Tocilizumab (Anti-Interleukin-6 Receptor Monoclonal) as a Potential Treatment for Chronic Antibody-Mediated Rejection and Transplant Glomerulopathy in HLA-Sensitized Renal Allograft Recipients

Extending the functional integrity of renal allografts is the primary goal of transplant medicine. The development of donor-specific antibodies (DSAs) posttransplantation leads to chronic active antibody-mediated rejection (cAMR) and transplant glomerulopathy (TG), resulting in the majority of graft losses that occur in the United States. This reduces the quality and length of life for patients and increases cost. There are no approved treatments for cAMR. Evidence suggests the proinflammatory cytokine interleukin 6 (IL-6) may play an important role in DSA generation and cAMR. We identified 36 renal transplant patients with cAMR plus DSAs and TG who failed standard of care treatment with IVIg plus rituximab with or without plasma exchange. Patients were offered rescue therapy with the anti-IL-6 receptor monoclonal tocilizumab with monthly infusions and monitored for DSAs and long-term outcomes. Tocilizumab-treated patients demonstrated graft survival and patient survival rates of 80% and 91% at 6 years, respectively. Significant reductions in DSAs and stabilization of renal function were seen at 2 years. No significant adverse events or severe adverse events were seen. Tocilizumab provides good long-term outcomes for patients with cAMR and TG, especially compared with historical published treatments. Inhibition of the IL-6-IL-6 receptor pathway may represent a novel approach to stabilize allograft function and extend patient lives.

Regulator of G protein signaling-1 modulates paraquat-induced oxidative stress and longevity via the insulin like signaling pathway in Caenorhabditis elegans

Insulin or insulin like signaling (IIS) pathway is a crucial pathway in Caenorhabditis elegans associated with mediating longevity, and stress resistance. Regulators of G protein signaling (RGS) also modulate stress resistance and longevity in multiple in vitro and in vivo models. However, the mechanism underlying RGS mediating stress resistance and longevity remains largely unclear. Here we report that rgs-1, an important member of rgs family, is a novel modulator of IIS pathway in C. elegans. We found that the loss of rgs-1 dramatically promoted paraquat resistance in C. elegans. Further genetic analyses demonstrated that rgs-1 acted downstream of daf-2 and upstream of age-1, pdk-1, daf-16. Instead of affecting those IIS-associated genes in transcriptional process, loss of rgs-1 promoted DAF-16's nucleus translocation and subset genes' expression in paraquat-induced oxidative status. By this way, rgs-1 mutant worms exhibited lower ROS damage and longer survival time than wild type worms when both exposed to paraquat. Other than paraquat exposure, rgs-1 mutant also promoted lifespan and cadmium resistance relying on daf-16. As rgs is evolutionarily conserved, our findings open a new insight into rgs family and its role in paraquat-induced oxidative stress and longevity in C. elegans or even mammals.

The Green Tea Polyphenol(-)-epigallocatechin-3-gallate and its beneficial roles in chronic kidney disease

Chronic kidney disease (CKD), a condition that affects around 10% of the population, has become a significant public health concern. Current therapeutic strategies to slow down the progression of CKD remain limited. Thus, it is urgent to develop new strategies to manage the patients with CKD. Work within the past decade has improved our understanding of the mechanisms contributing to CKD. In particular, oxidative stress as well as inflammation appears to play a pivotal role in CKD progression. ()-Epigallocatechin-3-gallate (EGCG), the major catechin of green tea extract, is known as a powerful antioxidant and reactive oxygen species scavenger. Various studies have shown EGCG has a potential role in chronic kidney disease models. It is suggested that EGCG modulates cellular and molecular mechanisms via inflammation-related NF-кB and Nrf2 signaling pathway, as well as apoptosis-related ER stress pathway and mitochondrial pathway. Therefore, based on these studies, this review attempts to present a recent state of our knowledge and understanding of mechanisms of its role on the process of CKD, with the aim of providing some clues for the future optimization of EGCG in renal diseases.

The redox sensitive glycogen synthase kinase 3β suppresses the self-protective antioxidant response in podocytes upon oxidative glomerular injury

The redox sensitive glycogen synthase kinase (GSK) 3 has been recently implicated in the pathogenesis of proteinuric glomerulopathy. However, prior studies are less conclusive because they relied solely on chemical inhibitors of GSK3, which provide poor discrimination between the isoforms of GSK3 apart from potential off target activities. In murine kidneys, the β rather than the α isoform of GSK3 was predominantly expressed in glomeruli and distributed intensely in podocytes. By employing the doxycycline-activated Cre-loxP site specific gene targeting system, GSK3β was successfully knocked out (KO) selectively in podocytes in adult mice, resulting in a phenotype no different from control littermates. Electron microscopy of glomeruli in KO mice demonstrated more glycogen accumulation in podocytes but otherwise normal ultrastructures. Upon oxidative glomerular injury induced by protein overload, KO mice excreted significantly less albuminuria and had much attenuated podocytopathy and glomerular damage. The anti-proteinuric and glomerular protective effect was concomitant with diminished accumulation of reactive oxygen species in glomeruli in KO mice, which was likely secondary to a reinforced Nrf2 antioxidant response in podocytes. Collectively, our data suggest that GSK3β is dispensable for glomerular function and histology under normal circumstances but may serve as a therapeutic target for protecting from oxidative glomerular injuries.

A modified nontransposed brachiobasilic arteriovenous fistula versus brachiocephalic arteriovenous fistula for maintenance hemodialysis access

OBJECTIVE

With the growing need for reliable and durable upper arm hemodialysis access, we sought to compare the performance of a novel modified nontransposed brachiobasilic arteriovenous fistula (mNT-BBAVF) with that of the more traditional brachiocephalic arteriovenous fistula (BCAVF).

METHODS

Briefly, to construct an mNT-BBAVF, an incision is made on the ulnar side of the elbow. The brachial artery and basilic vein are then isolated, and a side-to-side anastomosis is performed without transposition of the basilic vein. Next, the proximal basilic vein and the perforating veins within the surgical field are ligated. In this study, we retrospectively reviewed the medical records of all patients who underwent either an mNT-BBAVF or a BCAVF between January 2011 and October 2014 to compare 1-year primary unassisted patency, cumulative patency, and complications. We also examined hemodynamic parameters of vessels in each fistula type.

RESULTS

We identified a total of 84 patients: 45 had a BCAVF, and 39 had an mNT-BBAVF. The two groups were well matched for baseline characteristics. Maturation rates at 1 month were 97% for mNT-BBAVF and 96% for BCAVF. The 1-year primary unassisted patency was significantly higher in the mNT-BBAVF group than that in the BCAVF group (87% vs 67%; hazard ratio, 2.86; 95% confidence interval, 1.11-6.40; P = .03), although cumulative patency did not differ (90% vs 73%; hazard ratio, 2.80; 95% confidence interval, 0.98-6.96 ; P = .06). There were no differences in thrombosis, failure of maturation, bleeding, steal syndrome, arm swelling, aneurysm, and stenosis between the two groups during the 12-month study. Importantly, diameters and blood flow volumes of the proximal cephalic vein, distal cephalic vein, and distal basilic vein in patients who received an mNT-BBAVF increased significantly after 12 months. All three vessels met the Kidney Disease Outcomes Quality Initiative (KDOQI) criteria for fistula maturation and were available for dialysis cannulation, whereas only the proximal cephalic vein in the BCAVF group met the maturation criteria and could be used for cannulation.

CONCLUSIONS

mNT-BBAVF appeared to be an effective alternative to BCAVF for upper arm hemodialysis access.

Identification of apoptosis and macrophage migration events in paraquat-induced oxidative stress using a zebrafish model

AIMS

Paraquat (PQ) is a pesticide highly toxic to human beings, and a well-known trigger of oxidative stress. Although several animal models of PQ poisoning have been developed, some disadvantages limit their application in vivo. A zebrafish model was used in the present study to better define mechanisms of oxidative stress injury induced by PQ.

MAIN METHODS

The toxicity of PQ was evaluated in the AB strain of zebrafish, and apoptosis was assessed by acridine orange staining. Macrophage migration was identified using the TG (zlyz:EGFP) transgenic strain, and angiogenesis was observed using the fli1a-EGFP casper strain. Following the validation of gene changes by zebrafish-based in vivo quantitative real-time PCR, network analysis was performed using the Ingenuity Pathway Analysis software.

KEY FINDINGS

We first established the LC50 of PQ in the zebrafish model, and then found that robust oxidative stress and antioxidant genes were activated after PQ exposure. Moreover, apoptosis and distinct macrophage activation and migration were identified for the first time in PQ-exposed zebrafish. Utilizing this model, both extrinsic and intrinsic pathways involved in PQ-induced apoptosis were elucidated. We further demonstrated that macrophage migration was specifically induced by PQ, and that Rho family members and JNK-MMP13 signaling participated in this process.

SIGNIFICANCE

Zebrafish is a promising tool for investigating the mechanisms of oxidative stress injury induced by PQ, and for screening effective anti-oxidant drugs.

Prevalence, awareness, and treatment of anemia in Chinese patients with nondialysis chronic kidney disease: First multicenter, cross-sectional study

This was the first multicenter, cross-sectional survey to assess the prevalence of anemia, patient awareness, and treatment status in China. Data of patients with chronic kidney disease (CKD; age, 18-75 years; both out- and inpatients) from 25 hospitals in Shanghai, seeking medical treatment at the nephrology department, were collected between July 1, 2012 and August 31, 2012. The prevalence, awareness, and treatment of anemia in patients with nondialysis CKD (ND-CKD) were assessed. Anemia was defined as serum hemoglobin (Hb) levels ≤12 g/dL in women and ≤13 g/dL in men. A total of 2420 patients with ND-CKD were included. Anemia was established in 1246 (51.5%) patients: 639 (51.3%) men and 607 (48.7%) women. The prevalence of anemia increased with advancing CKD stage (χtrend = 675.14, P < 0.001). Anemia was more prevalent in patients with diabetic nephropathy (68.0%) than in patients with hypertensive renal damage (56.6%) or chronic glomerulonephritis (46.1%, both P < 0.001). Only 39.8% of the anemic patients received treatment with erythropoietin and 27.1% patients received iron products; furthermore, 22.7% of the patients started receiving treatment when their Hb level reached 7 g/dL. The target-achieving rate (Hb at 11-12 g/dL) was only 8.2%. Of the 1246 anemia patients, only 7.5% received more effective and recommended intravenous supplementation. Anemia is highly prevalent in patients with ND-CKD in China, with a low target-achieving rate and poor treatment patterns. The study highlights the need to improve multiple aspects of CKD management to delay the progression of renal failure.

Hyperamylasemia as an Early Predictor of Mortality in Patients with Acute Paraquat Poisoning

Background

Paraquat (PQ) is a non-selective and fast-acting contact herbicide which has been widely used in developing countries. Hyperamylasemia was reported in patients with PQ poisoning. This study investigated the predictive value and clinical characteristics of hyperamylasemia in patients with PQ poisoning.

Material/Methods

This study included 87 patients with acute PQ poisoning admitted from July 2012 to May 2015. Data were collected from medical records. Receiver operating characteristic (ROC) analysis was conducted to analyze the discriminatory potential of serum amylase with respect to 90-day mortality.

Results

Of 87 patients, 29 patients had elevated serum amylase. We found that serum amylase was significantly higher among patients with AKI than those with non-AKI (p<0.001), and was an independent predictor of mortality (hazard ratio [HR]=3.644; 95% [CI], 1.684–7.881; p=0.001). The area under the ROC curve for the serum amylase (area under curve [AUC]=0.796; 95% [CI], 0.690–0.903) had a better discriminatory potential than plasma PQ concentration (0.698;0.570–0.825) or urinary PQ concentration (0.647;0.514–0.781) in predicting 90-day mortality.

Conclusions

Hyperamylasemia is a valuable early predictor of 90-day mortality in PQ poisoning.

The β isoform of GSK3 mediates podocyte autonomous injury in proteinuric glomerulopathy

Converging evidence points to glycogen synthase kinase (GSK) 3 as a key player in the pathogenesis of podocytopathy and proteinuria. However, it remains unclear if GSK3 is involved in podocyte autonomous injury in glomerular disease. In normal kidneys, the β isoform of GSK3 was found to be the major GSK3 expressed in glomeruli and intensely stained in podocytes. GSK3β expression in podocytes was markedly elevated in experimental or human proteinuric glomerulopathy. Podocyte-specific somatic ablation of GSK3β in adult mice attenuated proteinuria and ameliorated podocyte injury and glomerular damage in experimental adriamycin (ADR) nephropathy. Mechanistically, actin cytoskeleton integrity in podocytes was largely preserved in GSK3β knockout mice following ADR insult, concomitant with a correction of podocyte hypermotility and lessened phosphorylation and activation of paxillin, a focal adhesion-associated adaptor protein. In addition, GSK3β knockout diminished ADR-induced NFκB RelA/p65 phosphorylation selectively at serine 467; suppressed de novo expression by podocytes of NFκB-dependent podocytopathic mediators, including B7-1, cathepsin L, and MCP-1; but barely affected the induction of NFκB target pro-survival factors, such as Bcl-xL. Moreover, the ADR-elicited podocytopenia and podocyte death were significantly attenuated in GSK3β knockout mice, associated with protection against podocyte mitochondrial damage and reduced phosphorylation and activation of cyclophilin F, a structural component of mitochondria permeability transition pores. Overall, our findings suggest that the β isoform of GSK3 mediates autonomous podocyte injury in glomerulopathy by integrating multiple podocytopathic signalling pathways.

Ornithine is a key mediator in hyperphosphatemia-mediated human umbilical vein endothelial cell apoptosis: Insights gained from metabolomics

AIMS

Hyperphosphatemia is associated with accelerated vascular endothelial dysfunction in patients with chronic kidney disease (CKD). The purpose of this study is to investigate the molecular mechanisms underlying hyperphosphatemia-caused endothelial dysfunction.

MAIN METHODS

The metabolic fingerprinting of human umbilical vein endothelial cells (HUVECs) subjected to hyperphosphatemia was characterized using an integrated metabolomics approach. HUVECs cultured in physiologically simulated hyperphosphatemia with or without phosphonoformic acid, a sodium-dependent phosphate transporter inhibitor (N=6) were collected for metabolomics analysis. Multivariate principle component analysis and partial least squares discriminant analysis were applied to analyze the metabolic data. The key metabolites were confirmed by quantitative analysis using liquid chromatography coupled with tandem mass spectrometer (LC-MS/MS).

KEY FINDINGS

36 metabolites were significantly altered in HUVECs following the challenges of hyperphosphatemia mimic, involving several metabolic pathways (all P<0.05). Among them, ornithine increased significantly in the HUVECs mediated by hyperphosphatemia mimic, and its levels positively correlated with cell apoptosis rate (r=0.674, P=0.002), and several additional metabolites in multiple metabolic pathways. The changes in the levels of ornithine and other several metabolites were supported by subsequent quantitative analyses using LC-MS/MS. Further study demonstrated that the increase in ornithine level may result from the increased expression of arginase 2 in HUVECs, which mediates the hydrolysis of arginine to form ornithine.

SIGNIFICANCE

This is the first study demonstrating ornithine a key molecule mediating hyperphosphatemia-induced apoptosis of ECs. Arginase 2 may be a therapeutic target for hyperphosphatemia-associated cardiovascular events.

N-acetylcysteine for the prevention of contrast-induced nephropathy in patients with pre-existing renal insufficiency or diabetes: a systematic review and meta-analysis

PURPOSE

To identify benefit of N-acetylcysteine (NAC) on patients with pre-existing renal insufficiency or diabetes.

BACKGROUND

NAC administration is a common method for prevention of contrast-induced nephropathy (CIN). Nevertheless, its benefit on patients with pre-existing renal insufficiency or diabetes remains uncertain and controversial.

METHODS

Randomized controlled trials (RCTs) to evaluate the efficacy of NAC for the prevention of CIN in patients with pre-existing renal insufficiency or diabetes were searched from the databases of MEDLINE, EMBASE, and Cochrane library. Pooled odds ratio (OR) with 95% confidence interval (95% CI) were calculated using fixed-effects model by the Mantel-Haenszel test.

RESULTS

Twenty RCTs involving 3466 subjects (1756 assigned to NAC and 1710 assigned to the control) were included in the pre-existing renal dysfunction group. Pooled analysis suggested a significant reduction in CIN among this group (OR, 0.76; 95% CI, 0.61-0.93; p = 0.008). However, the nine trials comparing NAC versus control among patients with diabetes (NAC, 367 subjects; control, 358 subjects) showed no benefit of NAC for prevention of CIN (OR = 0.87; 95% CI, 0.58-1.30; p = 0.50). No significant heterogeneity was detected (p = 0.07; I2 = 34% for the group of pre-existing renal dysfunction; p = 0.40; I2 = 5% for the group of diabetes).

CONCLUSION

Our results suggest that NAC decreases the incidence of contrast-induced nephropathy among patients with pre-existing renal insufficiency. The benefit was not existed in patients with diabetes.

Paraquat Poisoning Followed by Toxic Epidermal Necrolysis: A Report of Two Cases and Published Work Review

Toxic epidermal necrolysis (TEN) is a life-threatening, typically drug-induced, mucocutaneous disease. Whether paraquat, one of the most widely used herbicides, could induce TEN is not known. We describe 2 paraquat-poisoned patients with TEN. Both patients presented erythema after hospital discharge following initial paraquat poisoning and then developed a widespread eruption of diffuse erythema on almost the whole body, with bullae, epidermal necrosis and sloughing. They were successfully treated with intravenous immunoglobulin and methylprednisolone. These clinical features were consistent with TEN caused by medications with a high risk to induce Stevens-Johnson syndrome/TEN. Moreover, it is suggested that both skin exposure and ingestion of paraquat could induce TEN. To our knowledge, this is the first case report of TEN related to paraquat poisoning.

Pneumomediastinum predicts early mortality in acute paraquat poisoning

CONTEXT

In paraquat (PQ) poisoning, death often occurs after the appearance of pneumomediastinum (PM). However, the clinical features and eventual outcome of PM in PQ intoxication remains unclear.

OBJECTIVE

We aimed to characterize PM following PQ poisoning and its prognostic value for predicting mortality.

MATERIALS AND METHODS

Enrolled PQ-poisoned patients (n = 75) were divided into two groups according to whether PM could be detected by chest computed tomography or not. The study outcomes included 5- and 90-day death after intoxication. Survival curves were derived using the Kaplan-Meier method, and mortality risk factors were analyzed by forward stepwise Cox regression analysis.

RESULTS

PM was documented in 21.3% of the patients (16/75); in 13 of them PM set in within 3 days of PQ ingestion. 15 patients died within 3 days of appearance of PM. Compared with patients without PM, those with PM were younger (P = 0.011), and had higher scores of Acute Physiology and Chronic Health Evaluation (P < 0.001) and Sequential Organ Failure Assessment (P = 0.003). In addition, patients with PM had a higher incidence of acute renal failure (P = 0.001), toxic hepatitis (P = 0.008), and respiratory insufficiency (P = 0.003). PM predicted an increased risk of 90-day death (93.8% of patients with PM vs. 40.7% among those without PM; hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.0-5.6; P = 0.045), and increased risk of 5-day death (81.3% vs. 27.1%; HR, 3.2; 95% CI, 1.2-8.1; P = 0.017).

DISCUSSION AND CONCLUSION

Early PM, occurring within 8 days, is a specific predictor of mortality in PQ poisoning.

Green tea polyphenol (-)-epigallocatechin-3-gallate restores Nrf2 activity and ameliorates crescentic glomerulonephritis

Crescentic glomerulonephritis (GN) is the most severe form of GN and is associated with significant morbidity and mortality despite aggressive immunotherapy with steroids, cytotoxic drugs, and plasmapheresis. We examined the therapeutic efficacy of the green tea polyphenol (−)-epigallocatechin-3-gallate (EGCG, 50 mg/kg BW/day x3weeks), a potent anti-inflammatory and anti-oxidant agent, on experimental crescentic GN induced in 129/svJ mice by administration of rabbit anti-mouse glomerular basement membrane sera. Routine histology and key molecules involved in inflammatory and redox signaling were studied. EGCG treatment significantly reduced mortality, decreased proteinuria and serum creatinine, and markedly improved renal histology when compared with vehicle-treated mice. The improvements in renal function and histology were accompanied by the restoration of Nrf2 signaling (which was impaired in vehicle-treated mice) as shown by increased nuclear translocation of Nrf2 and cytoplasmic glutamate cysteine ligase catalytic subunit, glutamate cysteine ligase modifier subunit, and glutathione peroxidase. EGCG-treated mice also showed reduction in p-Akt, p-JNK, p-ERK1/2 and p-P38 as well as restoration of PPARγ and SIRT1 levels. Lower dose of EGCG (25 mg/kg BW/day x2 weeks) treatment also significantly decreased proteinuria and serum creatinine, and markedly improved renal histology when compared with vehicle-treated mice. Thus, our data illustrate the efficacy of EGCG in reversing the progression of crescentic GN in mice by targeting multiple signaling and inflammatory pathways as well as countering oxidative stress.

Diagnostic value of quantitative contrast-enhanced ultrasound (CEUS) for early detection of renal hyperperfusion in diabetic kidney disease

PURPOSE

To investigate the diagnostic value of quantitative contrast-enhanced ultrasound (CEUS) for early detection of renal hyperperfusion in diabetic kidney disease (DKD).

MATERIALS AND METHODS

55 DKD patients with estimated glomerular filtration rate (eGFR) >30 ml/min/1.73 m(2) and 26 normal controls (NCs) were enrolled. Clinical data was well documented. Blood samples were drawn for evaluation of renal function including blood urea nitrogen (BUN), serum creatinine (SCr) and serum uric acid (SUA), and urine samples were assayed for total protein quantification, and various microprotein markers. According to eGFR level, DKD patients were divided into early-stage DKD (eGFR ≥90 ml/min/1.73 m(2), n = 18) and middle-stage DKD (eGFR 30-90 ml/min/1.73 m(2), n = 37). Based on urinary microalbumin/creatinine ratio (MALB/UCR), early-stage DKD patients were further classified into two groups: MALB/UCR <10 g/mol (n = 11) and MALB/UCR ≥10 g/mol (n = 7). Then, CEUS was performed to observe the real-time renal perfusion, and low acoustic power contrast-specific imaging was used for quantitative analysis.

RESULTS

The renal perfusion images of CEUS were well developed successively. The corresponding perfusion curves based on echo-power signals in time series were constructed. Quantitative analysis showed that area under the descending curve (AUC2) was significantly increased in early-stage DKD compared to middle-stage DKD (p < 0.05), but AUC showed no significant difference. Further comparison between different MALB/UCR levels of early-stage DKD showed that patients with MALB/UCR ≥10 g/mol had significantly increased levels of AUC, AUC2 and proteinuria than patients with low MALB/UCR (p < 0.05). Also, high MALB/UCR DKD patients had increased proteinuria but similar eGFR compared to low MALB/UCR patients.

CONCLUSION

Renal microvascular hyperperfusion may be responsible for overt proteinuria until decline of renal filtration in DKD. AUC2 could be an early and sensitive marker for early renal injury and renal microvascular hyperperfusion in DKD.

Immune response of γδT cells in Schistosome japonicum-infected C57BL/6 mouse liver

Systematic evaluation of the role of γδT cells during the Schistosoma japonicum infection has not been reported, despite the fact that γδT cells contribute to many infectious diseases in innate immunity. Therefore, the aim of this study was to observe the properties of γδT cells in the liver of C57BL/6 mice infected by S. japonicum. In this report, using immuno-fluorescent histological analysis, γδT cells were found around hepatic granulomatous. Moreover, the flow cytometry results revealed that the percentage of hepatic γδT cells increased significantly after S. japonicum infection. More interestingly, a subset of CD3(-)γδTCR(+) cells were found and markedly increased after infection. Furthermore, expression of activation markers (CD25 and CD69) and cytokine profiles were detected in these hepatic CD3(+)γδTCR(+) and CD3(-)γδTCR(+) cells. The significantly higher level of CD69, IL-4 and IL-17 were observed in CD3(+)γδTCR(+) cells after infection, suggesting that CD3(+)γδTCR(+) cells instead of CD3(-)γδTCR(+) cells might play a predominant role during the infection. Finally, our results indicated that the expression of NKG2D on CD3(+)γδTCR(+) cells was higher than that on CD3(-)γδTCR(+) cells. Collectively, γδT cells could play an important role in the liver of C57BL/6 mouse during japonicum infection.

PSTK is a novel gene associated with early lung injury in Paraquat Poisoning

AIMS

Paraquat Poisoning (PQ) can cause illness and death, and its main causes of mortality are acute respiratory failure and lung fibrosis. Early recognition of this condition and early treatment are vital. Thus, it is of importance to target the key genes controlling pathogenesis in the early stage of PQ.

MAIN METHODS

C57BL/6 mice were used for Paraquat intragastric administration as a model of PQ. Following a gene chip-based screening, the change of gene expression in the lung was further validated by bioinformatic analyses, co-expression network construction and real-time RT-PCR, Western blot and immunofluorescence assays.

KEY FINDINGS

2287 genes with differential expression were identified at the very early stage of PQ. From these, 76 genes that were linked to mitochondrion function were further pursued. Among these genes, PSTK was a phosphorylase kinase which serves a protective role in oxidative stress lung damage. PSTK was the central gene in a 30-gene network that is important for mitochondrial complex I assembly, mitochondrial apoptosis and mitochondrial fatty acid beta-oxidation, suggesting that they could conceivably be related to the pathogenesis of PQ induced lung damage. Lastly, we confirmed that PSTK was lowered in rodent lungs following PQ.

SIGNIFICANCE

PSTK emerges as a central gene in a network of mitochondrial function genes in PQ exposed mice. The functional role of PSTK in PQ induced lung injury warrants further examination.

Pharmacological targeting of GSK3β confers protection against podocytopathy and proteinuria by desensitizing mitochondrial permeability transition

BACKGROUND AND PURPOSE

Mitochondrial dysfunction, triggered by mitochondria permeability transition (MPT), has been centrally implicated in the pathogenesis of podocytopathy and involves a multitude of cell signalling mechanisms, among which, glycogen synthase kinase (GSK) 3β has emerged as the integration point and plays a crucial role. This study aimed to examine the role of GSK3β in podocyte MPT and mitochondrial dysfunction.

EXPERIMENTAL APPROACH

The regulatory effect of GSK3β on MPT was examined in differentiated podocytes in culture and in a murine model of adriamycin-induced podocytopathy using 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), a highly selective small-molecule inhibitor of GSK3β.

KEY RESULTS

TDZD-8 therapy prominently ameliorated the proteinuria and glomerular sclerosis in mice with adriamycin nephropathy; this was associated with a correction of GSK3β overactivity in the glomerulus and attenuation of podocyte injuries, including foot process effacement and podocyte death. Consistently, in adriamycin-injured podocytes, TDZD-8 treatment counteracted GSK3β overactivity, improved cell viability and prevented death, concomitant with diminished oxidative stress, improved mitochondrial dysfunction and desensitized MPT. Mechanistically, a discrete pool of GSK3β was found in podocyte mitochondria, which interacted with and phosphorylated clyclophilin F, a key structural component of the MPT pore. TDZD-8 treatment prevented the GSK3β-controlled phosphorylation and activation of cyclophilin F, desensitized MPT and alleviated the damage to mitochondria in podocytes induced by adriamycin in vivo and in vitro.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that pharmacological targeting of GSK3β could represent a promising and feasible therapeutic strategy for protecting podocytes against mitochondrial dysfunction induced by oxidative injuries.

Contrast-enhanced ultrasonography is a valid technique for the assessment of renal microvascular perfusion dysfunction in diabetic Goto-Kakizaki rats

AIM

To evaluate the reliability of contrast-enhanced ultrasonography (CEUS) for the detection of renal microvascular blood perfusion in a type 2 diabetic Goto-Kakizaki (GK) rat model.

METHODS

Male GK and Wistar rats at the age of 4, 12 and 20 weeks (n=10, respectively) were used for the study. Real-time and haemodynamic imaging of the renal cortex was performed using CEUS with SonoVue. Outage time-intensity curves (TICs) were applied for the analysis of basic intensity, slope rates of the ascending (S1) and descending curves (S2), time to peak (TTP), half time of peak descending (HDT), peak intensity (PI), and total area under the curve (AUC). Immunohistochemical staining for endothelial cells (ECs) was performed using the CD34 monoclonal antibody for the quantification of microvessel density and distribution.

RESULTS

Images of the renal cortex microvascular beds after injection of SonoVue in the rats were rapidly and clearly displayed, and it is easy to differentiate the enhanced and faded images of renal perfusion. The TICs of the GK rats were much wider than the controls; however, no significant changes in PI were found in all aged rats. Ultrasonographic quantitative analysis revealed a decrease in S1 and S2, and an increase in TTP, HDT and AUC in the 12- and 20-week-old GK rats compared with the controls (P<0.05). Moreover, the 20-week-old GK rats had much lower glomerular density and smaller distribution area of CD34-positive ECs, which was in parallel with more severe proteinuria, GBM thickening, glomerulosclerosis and interstitial vascular damages (P<0.05). Interestingly, negative correlations between AUC and glomerular microvessel density or distribution were detected, respectively (P<0.05).

CONCLUSIONS

Contrast-enhanced ultrasonography is a valid technique for the real-time and dynamic assessment of renal cortex microvascular perfusion and haemodynamic characterization in GK rats.

Elevated cardiac markers in chronic kidney disease as a consequence of hyperphosphatemia-induced cardiac myocyte injury

Background

Elevated cardiac markers (CMs) and hyperphosphatemia are commonly encountered in patients with chronic kidney diseases (CKD), but the causal relationship between them has not been established.

Material/Methods

We enrolled 151 patients with different kidney functions in a cross-sectional study to explore the relationship of serum phosphorus with CMs, including cardiac troponin T (cTnT), myoglobin (MYO), creatine kinase-MB (CK-MB), and brain natriuretic peptide (BNP). Then, the effect of reducing phosphorus levels on CMs by taking phosphate binder for 3 months was prospectively observed in 64 hemodialysis patients. Finally, human cardiomyocytes were exposed to different concentrations of inorganic phosphorus to examine its underlying mechanism.

Results

1) Serum phosphorus and CMs gradually increased as the glomerular filtration rate declined in CKD patients (p<0.01). 2) Elevation of CMs was much greater and cardiac structure and function were worse in CKD patients who had higher serum phosphorus concentrations (p<0.05). 3) Serum phosphorus level positively correlated with cTnT, MYO, and BNP in CKD patients (p<0.001). 4) In hemodialysis patients, the reduction of cTnT, MYO, and CK-MB was synchronous with the pharmacologically-induced decline of serum phosphorus level. However, levels of serum Fibroblast growth factor 23 (FGF23) had no statistical decrease. 5) Simulated hyperphosphatemia inhibited proliferation of human cardiomyocytes in a time- and concentration-dependent manner.

Conclusions

Hyperphosphatemia may induce myocardial damage in CKD patients, possibly through triggering apoptosis of human cardiomyocytes, and this could account for the elevated cardiac markers in CKD patients.

Serum paraquat concentration detected by spectrophotometry in patients with paraquat poisoning

BACKGROUND

Paraquat (PQ) is a world-wide used herbicide and also a type of common poison for suicide and accidental poisoning. Numerous studies have proved that the concentration of serum PQ plays an important role in prognosis. Spectrophotometry, including common spectrophotometry and second-derivative spectrophotometry, is commonly used for PQ detection in primary hospitals. So far, lack of systematic research on the reliability of the method and the correlation between clinical features of patients with PQ poisoning and the test results has restricted the clinical use of spectrophotometry. This study aimed to evaluate the reliability and value of spectrophotometry in detecting the concentration of serum PQ.

METHODS

The wavelengths for detecting the concentration of serum PQ by common and second-derivative spectrophotometry were determined. Second-derivative spectrophotometry was applied to detect the concentration of serum PQ. The linear range and precision for detection of PQ concentration by this method were confirmed. The concentration of serum PQ shown by second-derivative spectrophotometry and HPLC were compared in 8 patients with PQ poisoning. Altogether 21 patients with acute poisoning 4 hours after PQ ingestion treated in the period of October 2008 to September 2010 were retrospectively reviewed. The patients were divided into higher and lower than 1.8 μg/mL groups based on their concentrations of serum PQ measured by second-derivative spectrophotometry on admission. The severity of clinical manifestations between the two groups were analyzed with Student's t test or Fisher's exact test.

RESULTS

The absorption peak of 257 nm could not be found when common spectrophotometry was used to detect the PQ concentration in serum. The calibration curve in the 0.4-8.0 μg/mL range for PQ concentration shown by second-derivative spectrophotometry obeyed Beer's law with r=0.996. The average recovery rates of PQ were within a range of 95.0% to 99.5%, relative standard deviation (RSD) was within 1.35% to 5.41% (n=6), and the lower detection limit was 0.05 μg/mL. The PQ concentrations in serum of 8 patients with PQ poisoning shown by second-derivative spectrophotometry were consistent with the quantitative determinations by HPLC (r=0.995, P<0.0001). The survival rate was 22.2% in patients whose PQ concentration in serum was more than 1.8 μg/mL, and the incidences of acidosis, oliguria and pneumomediastinum in these patients were 55.6%, 55.6% and 77.8%, respectively. These clinical manifestations were different significantly from those of the patients whose PQ concentration in serum was less than 1.8 μg/mL (P<0.05).

CONCLUSIONS

For common spectrophotometry, the wavelength at 257 nm was not suitable for detecting serum PQ as no absorbance was shown. Second-derivative spectrophotometry was reliable for detecting serum paraquat concentration. Serum PQ concentration detected by second-derivative spectrophotometry could be used to predict the severity of clinical manifestations of patients with PQ poisoning, and PQ content higher than 1.8 μg/mL 4 hours after ingestion could be an important predictive factor for poor prognosis.

Adoptive transfer of bone marrow dendritic cells failed to localize in the renal cortex and to improve renal injury in adriamycin nephropathy

BACKGROUND AND AIMS

Murine bone marrow (BM) dendritic cells (DCs) can be modulated to be tolerogenic by cytokines, such as interleukin (IL)-10 and transforming growth factor (TGF)-β, and may play a regulatory role and sustain immune hemostasis in cognate kidney disease. However, it is unknown whether BM-DCs can be used to protect against renal injury in murine Adriamycin nephropathy (AN).

METHODS

In this study, by adoptive in vivo transfer of BM-DCs, including immature DCs, mature DCs (lipopolysaccharide-stimulated DCs) and BM regulatory DCs (IL-10/TGF-β-modified DCs, DCregs), we addressed the potential benefits of BM-DCs in chronic kidney disease.

RESULTS

We found that after adoptive transfer of DCregs, renal injury, including glomerulosclerosis, interstitial fibrosis and tubular atrophy, was not changed compared to AN controls. Correspondingly, renal functions measured by serum creatinine, 12-hour urine protein and creatinine clearance were also not improved by transfusion with DCregs compared to AN controls.

CONCLUSION

This study showed that the adoptive transfer of BM-DCs was unable to improve renal injury in an AN model, and this failure related to their inability to access the kidney.

Delayed administration of a single dose of lithium promotes recovery from AKI

Evidence suggests that glycogen synthase kinase 3β (GSK3β) contributes to AKI; however, its role in post-AKI kidney repair remains uncertain. Here, delayed treatment with a single dose of lithium, a selective inhibitor of GSK3β and a US Food and Drug Administration-approved mood stabilizer, accelerated recovery of renal function, promoted repopulation of renal tubular epithelia, and improved kidney repair in murine models of cisplatin- and ischemia/reperfusion-induced AKI. These effects associated with reduced GSK3β activity and elevated expression of proproliferative molecules, including cyclin D1, c-Myc, and hypoxia-inducible factor 1α (HIF-1α), in renal tubular epithelia. In cultured renal tubular cells, cisplatin exposure led to transient repression of GSK3β activity followed by a prolonged upregulation of activity. Rescue treatment with lithium inhibited GSK3β activity, enhanced nuclear expression of cyclin D1, c-Myc, and HIF-1α, and boosted cellular proliferation. Similarly, ectopic expression of a kinase-dead mutant of GSK3β enhanced the expression of cyclin D1, c-Myc, and HIF-1α and amplified cellular proliferation after cisplatin injury, whereas forced expression of a constitutively active mutant of GSK3β abrogated the effects of lithium. Mechanistically, GSK3β colocalized and physically interacted with cyclin D1, c-Myc, and HIF-1α in tubular cells. In silico analysis revealed that cyclin D1, c-Myc, and HIF-1α harbor putative GSK3β consensus phosphorylation motifs, implying GSK3β-directed phosphorylation and subsequent degradation of these molecules. Notably, cotreatment with lithium enhanced the proapoptotic effects of cisplatin in cultured colon cancer cells. Collectively, our findings suggest that pharmacologic targeting of GSK3β by lithium may be a novel therapeutic strategy to improve renal salvage after AKI.

Redox-sensitive glycogen synthase kinase 3β-directed control of mitochondrial permeability transition: rheostatic regulation of acute kidney injury

Mitochondrial dysfunction plays a pivotal role in necroapoptotic cell death and in the development of acute kidney injury (AKI). Evidence suggests that glycogen synthase kinase (GSK) 3β resides at the nexus of multiple signaling pathways implicated in the regulation of mitochondrial permeability transition (MPT). In cultured renal tubular epithelial cells, a discrete pool of GSK3β was detected in mitochondria. Coimmunoprecipitation assay confirmed that GSK3β physically interacts with cyclophilin F and voltage-dependent anion channel (VDAC), key MPT regulators that possess multiple GSK3β phosphorylation consensus motifs, suggesting that GSK3β has a direct control of MPT. Upon a strong burst of reactive oxygen species elicited by the pro-oxidant herbicide paraquat, the activity of the redox-sensitive GSK3β was drastically enhanced. This was accompanied by augmented phosphorylation of cyclophilin F and VDAC, associated with MPT and cell death. Inhibition of GSK3β by either the selective inhibitor 4-Benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8) or forced expression of a kinase-dead mutant obliterated paraquat-induced phosphorylation of cyclophilin F and VDAC, prevented MPT, and improved cellular viability. Conversely, ectopic expression of a constitutively active GSK3β amplified the effect of paraquat on cyclophilin F and VDAC phosphorylation and sensitized cells to paraquat-induced MPT and death. In vivo, paraquat injection elicited marked oxidant stress in the kidney and resulted in acute kidney dysfunction and massive tubular apoptosis and necrosis. Consistent with in vitro findings, the activity of GSK3β was augmented in the kidney after paraquat injury, associated with increased phosphorylation of cyclophilin F and VDAC and sensitized MPT. TDZD-8 blocked GSK3β activity in the kidney, intercepted cyclophilin F and VDAC phosphorylation, prevented MPT, attenuated tubular cell death, and ameliorated paraquat-induced AKI. Our data suggest that the redox-sensitive GSK3β regulates renal tubular injury in AKI by controlling the activity of MPT regulators.

Acoustic radiation force impulse imaging for noninvasive evaluation of renal parenchyma elasticity: preliminary findings

OBJECTIVE

To evaluate the diagnostic value of acoustic radiation force impulse (ARFI) to test the elasticity of renal parenchyma by measuring the shear wave velocity (SWV) which might be used to detect chronic kidney disease (CKD).

METHODS

327 healthy volunteers and 64 CKD patients were enrolled in the study. The potential influencing factors and measurement reproducibility were evaluated in the healthy volunteers. Correlations between SWV and laboratory tests were analyzed in CKD patients.?Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance of ARFI.

RESULTS

The SWV of healthy volunteers correlated significantly to age (r = -0.22, P<0.001, n = 327) and differed significantly between men and women (2.06±0.48 m/s vs. 2.2±0.52 m/s, P = 0.018, n = 327). However, it did not correlate significantly to height, weight, body mass index, waistline, kidney dimension and the depth for SWV measurement (n = 30). Inter- and intraobserver agreement expressed as intraclass coefficient correlation were 0.64 (95% CI: 0.13 to 0.82, P = 0.011) and 0.6 (95% CI: 0.31 to 0.81, P = 0.001) (n = 40). The mean SWV in healthy volunteers was 2.15±0.51 m/s, while was 1.81±0.43 m/s, 1.79±0.29 m/s, 1.81±0.44 m/s, 1.64±0.55 m/s, and 1.36±0.17 m/s for stage 1, 2, 3, 4 and 5 in CKD patients respectively. The SWV was significantly higher for healthy volunteers compared with each stage in CKD patients. ARFI could not predict the different stages of CKD except stage 5. In CKD patients, SWV correlated to e-GFR (r = 0.3, P = 0.018), to urea nitrogen (r =  -0.3, P = 0.016), and to creatinine (r =  -0.41, P = 0.001). ROC analyses indicated that the area under the ROC curve was 0.752 (95% CI: 0.704 to 0.797) (P<0.001). The cut-off value for predicting CKD was 1.88 m/s (sensitivity 71.87% and specificity 69.69%).

CONCLUSION

ARFI may be a potentially useful tool in detecting CKD.

The level and distribution of ²²⁰Rn concentration in soil-gas in Guangdong Province, China

In order to understand the level and distribution of (220)Rn concentrations in soil-gas in the high-radiation-background area, an (220)Rn survey was carried out for the first time using a RAD7 portable radon monitor at 67 locations covering a total area of 1800 km(2) in the South of China. (220)Rn concentrations were significantly different from that in the surface areas covered by the weathered granite of Yanshan Period or Quaternary sediments. The (220)Rn concentrations varied between 6.65 and 461 kBq m(-3) and the averages were 294.42 ± 81.36 and 23.30 ± 25.84 kBq m(-3) for weathered granite products and sediments, respectively. A high positive correlation between (220)Rn concentrations and (232)Th activity concentrations was found. (220)Rn concentrations had no statistically significant variations from depths of 20-140 cm with an interval of 20 cm. It is worth paying attention to the problem of such a high soil (220)Rn concentration in Zhuhai City and Zhongshan City.

Inducing vortices in a Bose-Einstein condensate using holographically produced light beams

In this paper we demonstrate a technique that can create non-equilibrium vortex configurations with almost arbitrary charge and geometry in a Bose-Einstein condensate. We coherently transfer orbital angular momentum from a holographically generated light beam to a 87Rb condensate using a two-photon stimulated Raman process. Using matter wave interferometry, we verify the phase pattern imprinted onto the atomic wave function for a single vortex and a vortex-antivortex pair. In addition to their phase winding, the vortices created with this technique have an associated hyperfine spin texture.

Aqueous extract of Astragali Radix ameliorates proteinuria in adriamycin nephropathy rats through inhibition of oxidative stress and endothelial nitric oxide synthase

AIM OF THE STUDY

To investigate the effects of aqueous extract of Astragali Radix (ARE) on the oxidative stress status and endothelial nitric oxide synthase level in adriamycin (ADR) nephropathy rats.

MATERIALS AND METHODS

ADR nephropathy rats were randomly treated with ARE (2.5 g/kg/d, n=6, ARE group), or benazepril (10mg/kg/d, n=6, angiotensin-converting enzyme inhibitor (ACEI) group) for ten weeks. Serum urea nitrogen, creatinine, albumin, total protein, cholesterol and 24-h urinary protein concentration were determined. Renal cortex catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), malondialdehyde (MDA) activities, and 24-h urinary NO(3)(-)/NO(2)(-) excretion were determined by chromatometry. Renal cortex cyclic guanosine monophosphate (cGMP) level was measured by enzyme immunoassay and eNOS expression was determined by immunohistochemistry.

RESULTS

ARE and ACEI treatments could remarkably reduce more 24h urinary protein excretion than that in ADR group (88.32±9.96 mg, 81.78±16.28 mg vs. 153.91±28.63 mg, P<0.01), and there was no difference between ARE and ACEI group. Renal cortex CAT, GSH-Px activities in ARE and ACEI group were significantly higher than ADR group, and renal cortex SOD activity in ARE group was higher than ADR group. Renal cortex MDA activity, cGMP level, and glomerular and tubular eNOS expression in ARE and ACEI group were lower than that in ADR group, and 24-h urinary NO(3)(-)/NO(2)(-) excretion in ARE group was lower than ADR group. Renal cortex MDA content (r=0.895, P<0.01), cGMP content (r=0.666, P<0.01) and eNOS expression in glomerulus (r=0.910, P<0.01) were strongly positively associated with 24h urinary protein excretion. And renal cortex SOD content was negatively associated with 24h urinary protein excretion (r=-0.861, P<0.01).

CONCLUSIONS

ARE may ameliorate the proteinuria by suppressing the over expression of eNOS, and inhibiting the oxidative injury in ADR nephropathy rats.

Superoxide dismutase mimetic drug tempol aggravates anti-GBM antibody-induced glomerulonephritis in mice

Oxidative stress plays an important role in the pathogenesis of anti-glomerular basement membrane antibody-induced glomerulonephritis (anti-GBM-GN). Superoxide dismutase (SOD) is the first line of defense against oxidative stress by converting superoxide to hydrogen peroxide (H(2)O(2)). We investigated the effect of the SOD mimetic drug tempol on anti-GBM-GN in mice. 129/svJ mice were challenged with rabbit anti-mouse-GBM sera to induce GN and subsequently divided into tempol (200 mg.kg(-1).day(-1), orally) and vehicle-treated groups. Routine histology, SOD and catalase activities, malondialdehyde (MDA), H(2)O(2), and immunohistochemical staining for neutrophils, lymphocytes, macrophages, p65-NF-kappaB, and osteopontin were performed. Mice with anti-GBM-GN had significantly reduced renal SOD and catalase activities and increased H(2)O(2) and MDA levels. Unexpectedly, tempol administration exacerbated anti-GBM-GN as evidenced by intensification of proteinuria, the presence of severe crescentic GN with leukocyte influx, and accelerated mortality in the treated group. Tempol treatment raised SOD activity and H(2)O(2) level in urine, upregulated p65-NF-kappaB and osteopontin in the kidney, but had no effect on renal catalase activity. Thus tempol aggravates anti-GBM-GN by increasing production of H(2)O(2) which is a potent NF-kappaB activator and as such can intensify inflammation and renal injury. This supposition is supported by increases seen in p65-NF-kappaB, osteopontin, and leukocyte influx in the kidneys of the tempol-treated group.

Selective expression of S100A7 in lung squamous cell carcinomas and large cell carcinomas but not in adenocarcinomas and small cell carcinomas

BACKGROUND

S100A7 is a secreted protein and its overexpression has been previously associated with carcinogenesis of certain cancers. This study was undertaken to investigate the possibility that overexpression of S100A7 protein might be detected in the sera of patients with lung cancer.

METHODS

RNA and protein levels of S100A7 were examined in 60 pairs of frozen lung cancer tissues by RT-PCR and western blot. The specific expression of this protein and its cellular distribution were investigated in 145 paraffin embedded lung cancer samples, six benign lung disease and 21 normal lung tissues by immunohistochemistry. The S100A7 protein level was further analysed in serum from 112 patients with lung cancer, 20 with benign lung diseases and 31 healthy individuals by ELISA.

RESULTS

Specific expression of both S100A7 mRNA and protein was found in squamous cell carcinomas, adenosquamous carcinomas and large cell lung carcinomas, whereas neither was detected in adenocarcinomas or paired non-cancerous lung tissues. Further immunohistochemical analysis identified positive staining of S100A7 only in squamous cell carcinomas and large cell lung carcinomas, but not in other subtypes of lung cancer and normal lung tissues. Weak expression was also found in the inflammatory cells of benign lung diseases. Our most important finding is that elevated S100A7 protein could be detected in the sera of patients with squamous cell carcinomas.

CONCLUSION

S100A7 was only expressed in squamous cell carcinomas and large cell lung carcinomas and an increase in the level of S100A7 protein in serum may serve as a potential marker for lung cancer diagnosis.

[Effects of metal-catalyzed oxidation on the formation of advanced oxidation protein products]

OBJECTIVE

To explore the relationship between metal-catalyzed oxidation (MCO) and the formation of advanced oxidation protein products (AOPPs).

METHODS

Specimens of human serum albumin (HSA) and pooled plasma were collected from 3 healthy volunteers and 4 uremia patients were divided into 3 groups: Group A incubated with copper sulfate solution of the concentrations of 0, 0.2, or 0.5 mmol/L, Group B, incubated with hydrogen peroxide 2 mmol/L, and Group C, incubated with copper sulfate 0.2 or 0.5 mmol/L plus hydrogen peroxide 2 mmol/L. 30 min and 24 h later the AOPP level was determined by ultraviolet visible spectrophotometry. High-performance liquid chromatography (HPLC) was used to observe the fragmentation effect on plasma proteins. Ninhydrin method was used to examine the protein fragments. The scavenging capacity of hydroxyl radical by macromolecules was measured so as to estimate the extent of damage for proteins induced by MCO.

RESULTS

(1) The AOPP level of the HSA and plasma specimens of the uremia patients increased along with the increase of cupric ion concentration in a dose-dependent manner, especially in the presence of hydrogen peroxide (P < 0.05). (2) Aggregation of proteins was almost negligible in all groups, however, HPLC showed that cupric ion with or without hydrogen peroxide increased the fragments in the HAS specimens (with a relative molecular mass of 5000) and uremia patients' plasma proteins (with the molecular mass 7000). (3) The plasma AOPP level of the healthy volunteers was 68.2 micromol/L +/- 2.4 micromol/L, significantly lower than that of the uremia patients (158.5 micromol/L +/- 8.2 micromol/L). (4) The scavenging ability to clear hydroxyl radical by plasma proteins of the healthy volunteers was 1.38 -9.03 times as higher than that of the uremia patients.

CONCLUSION

MCO contributes to the formation of AOPPs mainly through its fragmentation effect to proteins.

Analysis of subcutaneous (SQ) alemtuzumab induction therapy in highly sensitized patients desensitized with IVIG and rituximab

Here we report on our experience with subcutaneous (SQ) Alemtuzumab in an uncontrolled study in highly HLA-sensitized patients (HS). From 3/05-4/07, 54 HS patients received Alemtuzumab 30 mg SQ as induction. Patient and graft survival, AR episodes, serum creatinines, absolute lymphocyte counts, monthly PCR monitoring for viruses, AE/SAEs and infectious complications were monitored. No patient to date has developed acute injection-related reactions after SQ Alemtuzumab; however, bone marrow suppression was occasionally seen requiring reduction or elimination of mycophenolate mofetil approximately 1-2 months posttransplant. Patient and graft survival at 12 M was 98%/96%, respectively. AR episodes occurred in 35% with 20% being C4d+ AMR. Mean SCrs at 12 M were 1.4 +/- 0.3 mg/dL. The nadir ALC was 0.17 +/- 0.19 within 24 h and sustained up to 365 days posttransplant. Infections occurred in eight patients (five with polyoma BK viremia [PBK], one CMV/PBK and two CMV viremia). SQ Alemtuzumab was well tolerated and resulted in prolonged lymphocyte depletion. Compared to our previous experience with daclizumab and rabbit ATG induction in HS patients, single-dose SQ Alemtuzumab was more cost effective, showed similar infection rates and did not reduce the AMR rates posttransplant. Although uncontrolled, these observations suggest that induction therapy with Alemtuzumab appears feasible and indeed promising, but awaits more definitive study.

Fibrillogenic amylin evokes the apoptosis of human mesangial cells

OBJECTIVE

To explore the apoptotic role of amylin on human mesangial cell (MC).

MATERIALS AND METHODS

Primarily cultured human MCs were applied and treated with fresh amylin preparation. Human MCs were identified by the morphology and immunofluorescence staining. The apoptotic cells were determined by ultrastructure changes, TUNEL, and DNA fragmentation analysis. Propidium iodide staining and flow cytometry was employed for quantitative measurement of apoptosis.

RESULTS

Under the light and transmission electronic microscopy (TEM), the human MCs with condensed chromatin, plasma shrinkage, marginated nuclear chromatin or apoptotic body were observed in amylin-treated MCs. Positive TUNEL staining, hypolipoid DNA peak, and typical DNA "ladder" pattern were also detected in amylin-treated MCs. Quantitative analysis of the apoptotic MCs showed that human amylin induced an increase of the percentage of apoptotic cells in a dose-dependent manner. Amylin nano-scale fibrils (5-18nm) in diameter were detected in the cultured solution using negative staining under the TEM. Compared to the control, no significant changes of lactate dehydrogenase release were observed in amylin-treated MCs (P>0.05).

CONCLUSIONS

Fibrillogenic amylin evokes the apoptosis of human MCs in vitro, which may explain the mechanism of the hypocellular mesangial damage and progressive glomerulosclerosis of the patients with diabetic nephropathy.

The onset of rapidly progressive neurologic deterioration after a brief gastrointestinal illness in a renal allograft recipient

Renal transplant recipients are at increased risk for life-threatening complications, most commonly infections. Because of their impaired cell-mediated immunity, these patients are particularly susceptible to organisms that rely on intracellular survival and spread, such as Listeria monocytogenes. Despite being a food-borne pathogen, L. monocytogenes is associated with significant morbidity and mortality. Here we report the case of a renal transplant recipient who developed rapidly progressive neurological symptoms after a brief gastrointestinal illness. Magnetic resonance imaging scan of the brain showed a large mass that was identified as an abscess due to L. monocytogenes. Timely aspiration and antibiotic treatment resulted in complete recovery, as opposed to worse outcomes in the available case reports. We further review the epidemiology, microbiology, clinical presentation, and therapeutic options for listerial brain abscess.

Amylin deposition in the kidney of patients with diabetic nephropathy

Amylin (islet amyloid peptide) plays a critical role in islet amyloidosis and in the development of beta-cell dysfunction in patients with diabetes; however, the involvement of amylin in renal amyloidosis has not been studied. For this reason, we surveyed 149 patients with biopsy-proven diabetic nephropathy (DN). The results were compared to 95 renal disease control patients, which included membranoproliferative glomerulonephritis, light-chain deposition, IgA nephropathy, and obesity-related glomerulopathy (ORG). Seventy-two of the 149 patients with DN showed amylin deposition in their renal tissue. Amylin was mainly distributed in the expanded mesangial area, Kimmelstiel-Wilson nodules, Bowman's capsule, and in blood vessels. The frequencies of mesangial proliferation, glomerular nodule lesions, and glomerular sclerosis were higher in DN patients with amylin deposits. Furthermore, the tubular interstitial lesions were more severe in these patients. Of the 95 disease-control patients, four with ORG were positive for renal amylin deposits. Our study has found renal amylin deposition in patients with DN and that the deposition was associated with disease severity. We suggest that strict metabolic control and reversing insulin resistance in patients with diabetes may blunt the process of amylin deposition in the kidney and possibly protect renal function in these patients.

Effect of induction therapy protocols on transplant outcomes in crossmatch positive renal allograft recipients desensitized with IVIG

Here we retrospectively examine the efficacy of two antibody induction regimens using Zenapax or Thymoglobulin in patients with positive complement-dependent cytotoxicity crossmatches (CDC-CMXs) desensitized with IVIG (intravenous immunoglobulin). Between January 1999 and March 2005, 97 patients with (+) CDC-CMXs received kidney transplants (43 deceased donors/54 living donors). All patients received at least 2 g/kg IVIG (maximum four doses) until an acceptable CMX was obtained. Patients were divided into two groups: 1. IVIG + Zenapax (n = 58), 2. IVIG + Thymoglobulin (n = 39). A total of 94% of patients in Group 1 and 84% in G2 have at least 2 years of follow up. Patient and graft survival was 96%/84% in Group 1 and 100%/90% in Group 2, p = NS. The number and severity of AR episodes were similar (36% Group 1 vs. 31% Group 2, p = NS) as was the incidence of C4d (+) antibody-mediated rejection (AMR) (Banff Grade II/III) (22% Group 1 vs. 21% Group 2). Mean serum creatinines (SCrs) at 24 months were similar (Group 1: 1.4 +/- 0.7 vs. G2: 1.5 +/- 0.7 mg/dL). Induction therapy with Zenapax or Thymoglobulin results in excellent patient, graft survival and graft function at 2 years. There was no increased risk of viral infections or malignancies with either agent. Neither agent was effective in reducing the incidence of AMR.

Intravenous gammaglobulin (IVIG): a novel approach to improve transplant rates and outcomes in highly HLA-sensitized patients

Intravenous immunoglobulin (IVIG) products are derived from pooled human plasma and have been used for the treatment of primary immunodeficiency disorders for more than 24 years. Shortly after their introduction, IVIG products were also found to be effective in the treatment of autoimmune and inflammatory disorders. Over the past 2 decades, the list of diseases where IVIG has a demonstrable beneficial effect has grown rapidly. These include Kawasaki disease, Guillain-Barre syndrome, myasthenia gravis, dermatomyositis and demyelinating polyneuropathy. Recently, we have described a beneficial effect on the reduction of anti-HLA antibodies with subsequent improvement in transplantation of highly HLA-sensitized patients as well as a potent anti-inflammatory effect that is beneficial in the treatment of antibody-mediated rejection (AMR). These advancements have enabled transplantation of patients previously considered untransplantable. These studies and relevant mechanism(s) of action will be discussed here.

Herbal treatment for renal diseases

Renal fibrosis is a common consequence of chronic kidney diseases (CKD). Standard therapy to prevent progression of CKD in western medicine includes dietary protein restriction, blood pressure control, angiotensin-converting enzyme inhibition and angiotensin receptor blockade. However, little is known about the renoprotective effects of Chinese herbal medicine. Cumulative evidence suggests that some Chinese herbal medicines, including Astragalus and a mixture of Astragalus plus Angelica, Ligusticum, Triptolide and Rhubarb, have a beneficial role in slowing the progression of CKD. This effect is multi-functional and multi-targeted, and is often associated with a reduction in proteinuria and the amelioration of dyslipidaemia, but not with changes in systemic blood pressure. These mechanisms include anti-inflammation and inhibition of TGF-b overproduction. On the other hand, some Chinese herbal medicines may be hazardous to patients with renal diseases. In this review, we discuss recent advances in the research of some Chinese herbs for pharmacological intervention of progressive renal diseases and kidney-related injuries.