Second and Third Kidney Transplants.

Renal transplant is the best procedure for patients with end-stage renal disease. Although an ideal kidney transplant should survive for the lifetime of each recipient, there may be a need for a second, third, or even a fourth retransplant. The outcomes of these kidney allografts, surgical approaches, immunology issues, and drug therapies warrant greater focus. Pediatric kidney retransplant is even more important because these patients are more immunologically responsive to donor antigens and because they need longer allograft survival. Although kidney retransplant provides a survival advantage for patients who would otherwise remain on the wait list and/or hemodialysis, careful patient selection is crucial for second, third, and fourth renal transplants. Despite the shortage of donor organs, outcomes, manageable complications, and economic considerations support earlier kidney retransplants rather than delayed retransplants. Preoperative vascular imaging, appropriate induction therapy, regular monitoring of renal function, and regular surveillance for malignancy and infection are more important in the retransplanted kidneys than in cases of first kidney transplants. The lack of robust data on optimal clinical management of these retransplant recipients has contributed to substantial variations in clinical practice among different centers. In this review, we discuss medical and surgical approaches in the cases of second and third kidney transplants.

The Effects of Remdesivir and Dexamethasone on Renal Sirtuin-1 Expression and Renal Function in Male Rats.

Remdesivir (REM) and dexamethasone (DEX) both have been used to treat coronavirus disease 2019 (COVID-19). The present study aimed to evaluate the effects of REM and DEX on kidney structure and function with particular focus on the probable renal sirtuin-1 (SIRT1) expression alteration in rats. Twenty-four male Wistar rats were divided into four groups, as follows: group A (control) received normal saline (5 mL/kg/day for 10 days); group B (REM) received REM (17 mg/kg/day on the first day, and 8.5 mg/kg/day on the 2nd-10th days); group C (REM + DEX) received both REM (17 mg/kg/day on the first day, and 8.5 mg/kg/day on the 2nd-10th days) and DEX (7 mg/kg/day, for 10 days); group D (DEX) received DEX (7 mg/kg/day for 10 days). Renal SIRT1 expression and kidney structure and function-related factors were evaluated by standard methods. The mean levels of urea in the REM + DEX group (60.83 ± 6.77, mg/dL) were significantly higher than in the control (48.33 ± 3.01, mg/dL; p = 0.002) and DEX (51.22 ± 4.99, mg/dL; p = 0.018) groups. The mean levels of creatinine in the REM (0.48 ± 0.08, mg/dL) and REM + DEX (0.50 ± 0.04, mg/dL) groups were higher than in the control group (48.33 ± 3.0 mg/dL) significantly (p = 0.022 and p = 0.010, respectively). The renal SIRT1 expression was significantly (p = 0.018) lower in the REM + DEX group (0.36 ± 0.35) than in the control group (1.34 ± 0.48). Tubulointerstitial damage (TID) scores in REM + DEX-treated rats (2.60 ± 0.24) were significantly higher than in the control (0.17 ± 0.17, p = 0.001) and DEX (0.50 ± 0.29, p = 0.005) groups. The administration of DEX and REM might lead to kidney injury associated with SIRT1 downregulation.

Effect of Lower- versus Higher-Intensity Isometric Handgrip Training in Adults with Hypertension: A Randomized Controlled Trial.

This study compared the effects of lower- versus higher-intensity isometric handgrip exercise on resting blood pressure (BP) and associated clinical markers in adults with hypertension. Thirty-nine males were randomly assigned to one of three groups, including isometric handgrip at 60% maximal voluntary contraction (IHG-60), isometric handgrip at 30% IHG-30, or a control group (CON) that had been instructed to continue with their current activities of daily living. The volume was equated between the exercise groups, with IHG-60 performing 8 × 30-s contractions and IHG-30 performing 4 × 2-min contractions. Training was performed three times per week for 8 weeks. Resting BP (median [IQR]), flow-mediated dilation, heart rate variability, and serum markers of inflammation and oxidative stress were measured pre- and post-intervention. Systolic BP was significantly reduced for IHG-60 (−15.5 mmHg [−18.75, −7.25]) and IHG-30 (−5.0 mmHg [−7.5, −3.5]) compared to CON (p < 0.01), but no differences were observed between both the exercise groups. A greater reduction in diastolic BP was observed for IHG-60 (−5.0 mmHg [−6.0, −4.25] compared to IHG-30 (−2.0 mmHg [−2.5, −2.0], p = 0.042), and for both exercise groups compared to CON (p < 0.05). Flow-mediated dilation increased for both exercise groups versus CON (p < 0.001). IHG-30 had greater reductions in interleukin-6 and tumor necrosis factor-α compared to the other groups (p < 0.05) and CON (p = 0.018), respectively. There was a reduction in Endothelin-1 for IHG-60 compared to CON (p = 0.018). Both the lower- and higher-intensity IHG training appear to be associated with reductions in resting BP and improvements in clinical markers of inflammation and oxidative stress.

Expanded Criteria Donors.

The expanded criteria donor is any donor over the age of 60 years or a donor over the age of 50 years with 2 of the following 3 items: (1) history of high blood pressure, (2) serum creatinine ≥1.5 mg/dL, and (3) death due to stroke. To accept an expanded criteria donor kidney may significantly decrease the amount of time a person waits for transplant but requires written informed consent from the recipient. Although expanded criteria donor kidneys have predictably shorter outcomes than standard criteria donors, the exact risk is unknown. At 5 years follow-up, 50% of expanded criteria donor kidneys are still working. Regardless of donor status of these kidneys as expanded criteria or standard criteria, the transplant recipients have higher survival rates compared with candidates who remain on the wait list. The success rate may be increased when a perfusion pump is used to preserve the kidneys. Sometimes the function of a single kidney from an expanded criteria donor is deemed insufficient. In this situation, a pair of marginally functioning kidneys may be transplanted as a dual-kidney transplant. This dual transplant option offers acceptable outcomes as good as a single-kidney transplant with normal function and can effectively address the shortage of donor organs. The use of a perfusion pump allows the clinician to decide whether or not to use a particular expanded criteria donor kidney. Expanded criteria donors may be justified by meticulous selection of each donor for recipients, along with more sophisticated surgical techniques to maximize the kidney donor pool.

Donation After Cardiac Death in Children.

The wait list for organ transplant exceeds the rate of organ donation, especially in children. The solid-organ transplant rate has remained stable over time, despite increased demand. Although donation after cardiac death has helped to expand the donor organ pool for the adult population, this option remains scarce for children in need of transplant. Because long-term graft survival is more important in the pediatric group than in adults, we should reconsider the common notion that donation after cardiac death is inferior to donation after brain death. Herein, we review the literature to extract and analyze data regarding donation after cardiac death for solid-organ transplant in children.

Ameliorative effect of a nano chromium metal-organic framework on experimental diabetic chronic kidney disease.

Metal-Organic Frameworks (MOFs) are a new class of crystalline porous structures which can be used as a novel structure in diverse fields of medical science. Several studies have shown that chromium supplementation can be effective in amelioration of biochemical parameters of diabetes and its renal complications. Therefore, a chromium-containing MOF (DIFc) was synthetized by nanochelating technology in the present study and then its effect on biochemical indices in diabetic rats was evaluated. Diabetes was induced by high-fat diet consumption and streptozotocin (35 mg/kg) injection and then the treatment started 8 weeks after disease induction and continued for 8 weeks. The results showed that DIFc treatment decreased HOMA-IR index, blood urea nitrogen, uric acid and malondialdehyde in plasma samples. This nano MOF also reduced albumin, malondialdehyde and 8-isoprostane in urine specimen, while it increased creatinine clearance. In conclusion, DIFc MOF demonstrated promising results in the present study, indicating that it can be developed and evaluated in future investigations with the aim of designing a novel agent for management of diabetes and its renal complications.

Protection of renal damage by HMG-CoA inhibitors: A comparative study between atorvastatin and rosuvastatin.

OBJECTIVES: Hypercholesterolemia is a common metabolic disorder in developing and developed countries and is associated with the increased rates of chronic kidney disease (CKD). Statin therapy could reduce cholesterol synthesis as well as progression of CKD. Diversity between statins causes variety in pharmacokinetics and pharmacodynamics and also their pleiotropic effects. In the present investigation we aimed to evaluate the protective potentials of both atorvastatin (Ator) (as lipid-soluble statin) and rosuvastatin (Ros) (as water-soluble statin) against renal histopathological damages in the high cholesterol diet induced hypercholesterolemic rats (HCDIHR). MATERIALS AND METHODS: Serum lipid profile, oxidized low density lipoprotein (OX-LDL), malondialdehyde (MDA), urea and creatinine levels, as well as renal histopathology were evaluated. RESULTS: While Ros acted better than Ator to reduce serum low density lipoprotein cholesterol (LDL-C) (P<0.01), atherogenic index (AI) (P<0.01), MDA (P<0.01), and OX-LDL (P<0.01); no significant differences were noted in their cholesterol (P=0.72), triglyceride (TG) (P=0.79), and very low density lipoprotein cholesterol lowering (VLDL-C) (P=0.79) and high density lipoprotein cholesterol elevating effects (HDL-C) (P=0.72). Ator was more effective to reduce renal histopathologic indices compared to Ros, including accumulation of lipid droplet, glomerular foam cells, mesangial cell proliferation, renal hemorrhage, and tubulointerstitial damages in the kidneys of diet induced hypercholesterolemic rats. CONCLUSION: The findings underline that the lipophilic Ator may performs better than Ros in attenuating renal damages in HCDIHR.

DIBc nano metal-organic framework improves biochemical and pathological parameters of experimental chronic kidney disease.

BACKGROUND: The growing morbidity and mortality rate of chronic kidney disease (CKD) has forced researchers to find more efficient strategies for controlling this disease. Studies have proven the important role of alteration in iron, zinc and selenium metabolism in CKD pathological process. Nanotechnology, through synthetizing nano metal-organic framework (NMOF) structures, can be employed as a valuable strategy for using these trace elements as the key for modification and improvement of CKD-related pathological events. After proving the anti-diabetic property of DIBc NMOF (which contains selenium and zinc) in the previous study, the impact of this NMOF on some important biochemical and pathological parameters of CKD was evaluated in the current study. METHODS: Knowing that diabetic nephropathy (DN) is the leading cause of CKD, male wistar rats were selected and given a high fat diet for 2 weeks and then were injected with streptozotocin (35 mg/kg) to induce DN. Six weeks after streptozotocin injection, DIBc or metformin treatment started and continued for 8 weeks. RESULTS: Eight weeks of DIBc treatment decreased plasma fasting blood glucose, blood urea nitrogen, uric acid, malondialdehyde (MDA) and HOMA-IR index compared to DN control and metformin groups. This NMOF significantly reduced urinary albumin excretion rate, MDA and 8-isoprostane, while it increased creatinine clearance in comparison to the above-mentioned groups. Renal histo-pathological images indicated that DIBc ameliorated glomerular basement membrane thickening and wrinkling, mesangial matrix expansion and hypercellularity and presence of intra-cytoplasmic hyaline droplets in proximal cortical tubules of kidney samples. CONCLUSION: The results showed the therapeutic effect of DIBc on important biochemical and histo-pathological parameters of CKD, so this NMOF could be regarded as a promising novel anti-CKD agent.

BCc1 Nanomedicine Therapeutic Effects in Streptozotocin and High-Fat Diet Induced Diabetic Kidney Disease.

BACKGROUND: One common feature of chronic diseases, such as cancer, diabetes and chronic kidney disease (CKD), is the disruption of iron metabolism and increase in labile iron pool, which can result in excessive production of harmful oxidative stress. The proper management of iron metabolism in this situation can be a valuable tool to ameliorate pathological events. MATERIALS AND METHODS: In the previous studies, the anti-neoplastic effects of BCc1, a nanochelating-based nanomedicine with iron-chelating property, were demonstrated in cell culture, animal models and clinical trials. In the present study, the therapeutic effects of BCc1 in animal model of diabetic kidney disease (DKD), induced by streptozotocin injection (35 mg/kg) and high-fat diet consumption, were evaluated. RESULTS: The results showed that BCc1 significantly decreased HOMA-IR index, uric acid, blood urea nitrogen, malondialdehyde and 8-isoprostane. In addition, it reduced urinary albumin excretion rate and albumin-to-creatinine ratio in comparison to DKD control rats. This nanomedicine had no negative impact on liver iron content, hemoglobin level, red blood cell count, hematocrit and mean corpuscular volume, while it significantly decreased aspartate aminotransferase and alanine aminotransferase compared to DKD control group. Moreover, the histopathological assessment indicated that lesser glomerular basement membrane and wrinkling, mesangial matrix expansion and pathological changes in proximal cortical tubules were seen in the kidney samples of BCc1-treated rats. CONCLUSION: In conclusion, BCc1 as an iron-chelating agent shows promising impacts in DKD animal model, which can ameliorate biochemical and pathological events of this disease.

Empagliflozin Attenuates Renal and Urinary Markers of Tubular Epithelial Cell Injury in Streptozotocin-induced Diabetic Rats.

Empagliflozin, a SGLT-2 inhibitor, improves diabetic nephropathy through its pleiotropic anti-inflammatory effects. The present study aims to evaluate empagliflozin effects on renal and urinary levels of tubular epithelial cell injury markers in streptozotocin-induced diabetic rats. Empagliflozin at 10 mg/kg (p.o.) was administered for 4 weeks, beginning 8 weeks after induction of diabetes. Renal function as well as markers of renal tubular epithelial cell injury were assessed in kidney tissue homogenates and urine. Empagliflozin was able to ameliorate diabetes induced elevations in serum cystatin C levels. It also alleviated renal KIM-1/NGAL levels and urinary albumin, α-GST, and RBP excretions. In addition to decreasing urinary levels of cell cycle arrest indices i.e. TIMP-2 and IGFBP7, empagliflozin mitigated acetylated NF-κB levels in renal tissues of diabetic rats. As a whole, these findings reveal empagliflozin capability in improving diabetic nephropathy via ameliorating indices of renal inflammation, injury, and cell cycle arrest on streptozotocin-induced diabetic rats.

New Markers for Transplant Rejection.

Monitoring allograft function after kidney transplant has routinely relied on the use of nonspecific markers, such as serum creatinine, glomerular filtration rate, proteinuria, and donor-specific antibodies. These traditional markers have low sensitivity and fail to detect subclinical changes. Diagnosis of renal allograft dysfunction still requires an allograft biopsy, as it remains the criterion standard for assessment of graft status. However, renal biopsy is an invasive procedure, and sampling errors may result in misdiagnosis, perhaps causing graft failure. New biomarkers have been developed to monitor allograft function, although many are not yet routinely used. Other shortcomings, such as lack of standardization and high cost, should be solved before their widespread application in the clinic. A recipient's immune status could be monitored by use of urine or blood samples. These include functional cell-based assays and the evaluation of molecular expression at the messenger RNA or protein levels. Molecular technologies, including molecular microscope diagnostic systems, have been recently developed to improve the yield of histologic evaluation of the allograft biopsy. Prospective, interventional trials are required to demonstrate whether these new biomarkers improve patient or transplant outcomes. Implementation of these technologies into standard clinical practice remains challenging until their generalizability, cost, ease of interpretation, and the identification of patients who may benefit from more than standard-of-care surveillance can be determined. These biomarkers could allow immunosuppressive therapy to be individualized for patients.

Sodium-glucose co-transporters and diabetic nephropathy: Is there a link with toll-like receptors?

The incidence of diabetes mellitus (DM) has increased alarmingly over the last decades. Despite taking measures aimed at controlling hyperglycaemia and blood pressure, the rate of end-stage renal disease (ESRD) is continually growing. Upon increased amounts of advanced glycation end products (AGEs) and their correspondent receptors (RAGEs), AGE-RAGE axis is over-activated in DM, being the first step in the initiation and propagation of inflammatory cascades. Meanwhile, HMGB1, released from damaged cells in the diabetic kidneys, is the most notable ligand for the highly expressed toll-like receptors (TLRs) and RAGEs. TLRs play an indispensable role in the pathogenesis of diabetic nephropathy. Sodium-glucose co-transporter 2 (SGLT-2) inhibitors are hypoglycaemic agents acting on the renal proximal tubules to prevent glucose reabsorption and therefore increase urinary glucose excretion. Besides improving glycaemic control, these hypoglycaemic agents possess direct renoprotective properties. Here, therefore, we review the most recent findings regarding interrelationship between SGLT2 inhibitors and HMGB1-TLR4 axis.

The impact of dyslipidemia and oxidative stress on vasoactive mediators in patients with renal dysfunction.

Hyperlipidemia and oxidative stress are indispensable features of chronic kidney disease (CKD) that favor the development of atherogenic plaques and cardiovascular disease (CVD). A number of vasoactive mediators including proprotein convertase subtilisin-kexin type 9 (PCSK9), endothelin-1, nitric oxide, and angiotensin II have fundamental roles in the pathophysiology of atherosclerotic events; moreover, their levels are affected by dyslipidemia and oxidative stress due to renal dysfunction. Therefore, therapeutic measures aimed at correcting dyslipidemia and alleviating oxidative stress could potentially protect against CVD in CKD patients. In this review, we discuss the relation between dyslipidemia, oxidative stress, and vasoactive mediators as well as the available treatment options against these disturbances in CKD patients.

The effect of oral melatonin on renal ischemia-reperfusion injury in transplant patients: A double-blind, randomized controlled trial.

BACKGROUND: One of the important factors in the occurrence of acute kidney injury (AKI) among renal transplant patients (RTPs) is ischemia reperfusion injury (IRI). The current study aimed at determining the anti-inflammatory and anti-oxidative effects of melatonin on the complications of IRI and the level of Klotho expression in these patients. METHODS: A total of 40 renal transplant candidates were randomly assigned into placebo or melatonin group receiving the same dose of 3 mg/day. In order to measure serum melatonin levels, inflammatory and oxidative stress factors, renal function biomarkers, and Klotho gene/protein expression, venous blood samples were taken from patients over two different time points, i e, 24 h before the transplantation and at discharge from hospital. RESULTS: Melatonin was associated with improvement in renal transplantation, since the serum level of neutrophil gelatinase-associated lipocalin, as a renal functional marker, significantly decreased (P < .001). The effect of melatonin as a suppressor of inflammation and oxidative stress was also evident in the melatonin group due to a significant reduction in the serum levels of MDA, CP, 8-OHdG, and TNF-α markers (P < .001). CONCLUSIONS: Reduction in serum levels of renal function and oxidative stress/inflammatory markers in the melatonin group indicates that melatonin can inhibit IRI outcomes in RTPs through its anti-oxidant and anti-inflammatory properties. However, these properties do not appear as a result of influence on the level of Klotho gene/protein expression.

Empagliflozin alleviates renal inflammation and oxidative stress in streptozotocin-induced diabetic rats partly by repressing HMGB1-TLR4 receptor axis.

OBJECTIVES: Empagliflozin, a sodium-glucose cotransporter-2 (SGLT-2) inhibitor, possesses verified anti-inflammatory and anti-oxidative stress effects against diabetic nephropathy. The present investigation aims to examine empagliflozin effects on the renal levels of high mobility group box-1 (HMGB1), a potent inflammatory cytokine, and its respective receptor toll-like receptor-4 (TLR-4) in STZ-induced diabetic rats. MATERIALS AND METHODS: Empagliflozin at 10 mg/kg per os (p.o.) was administered for 4 weeks, starting 8 weeks after the induction of diabetes. Renal function, kidney inflammation, oxidative stress, and apoptosis markers as well as renal HMGB1, receptor for advanced glycation end products (RAGE), and TLR-4 levels were assessed. RESULTS: In addition to down-regulating NF-κB activity in renal cortices, empagliflozin reduced renal levels of HMGB1, RAGE, and TLR-4. It alleviated renal inflammation as indicated by diminished renal expressions of inflammatory cytokines and chemokines like tumor necrosis factor-alpha (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) and also decreased urinary levels of interleukin-6 (IL-6) and alpha-1 acid glycoprotein (AGP). Moreover, empagliflozin ameliorated renal oxidative stress as demonstrated by decreased renal malondialdehyde (MDA) and elevated renal activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX). It also suppressed renal caspase-3, the marker of apoptosis; and furthermore, enhanced renal function noticed by the declined levels of serum urea and creatinine. CONCLUSION: These findings underline that empagliflozin is able to attenuate diabetes-related elevations in renal HMGB1 levels, an influential inflammatory cytokine released from the necrotic and activated cells, and its correspondent receptors, i.e., RAGE and TLR-4.

Tangeretin protects renal tubular epithelial cells against experimental cisplatin toxicity.

OBJECTIVES: Cisplatin is an effective antineoplastic agent; its clinical utility, however, is limited by a few salient toxic side effects like nephrotoxicity. This study aimed to determine the potential protective effects of tangeretin, a citrus-derived flavonoid, against renal tubular cell injury in cisplatin-induced renal toxicity of rats. MATERIALS AND METHODS: Tangeretin was injected intraperitoneally at 2.5 and 5 mg/kg doses for 10 days, and a single dose of cisplatin (8 mg/kg) was injected on the 7th day. Tests of kidney function and tubular injury in renal tissues and urine together with oxidative stress and inflammation markers were examined. RESULTS: Tangeretin ameliorated cisplatin-induced elevations in serum creatinine, BUN, and histopathologic changes. It also attenuated kidney oxidative stress elicited by cisplatin as demonstrated by reduced MDA and increased GSH, CAT, and SOD activities, elevated Nrf2 expression and protein levels of its downstream effectors, HO-1 and NQO-1. Tangeretin further alleviated inflammation evoked by cisplatin as indicated by reduced NF-κB p65 subunit phosphorylation with a simultaneous decrement in its downstream effectors IL-1ß and TNF-α expression and protein levels. Moreover, it declined caspase-3 protein levels and TUNEL positive cells in the kidneys, the markers of apoptosis and DNA fragmentation, thus improving renal endurance. Additionally, tangeretin mitigated renal levels of KIM-1 and NGAL, as well as urinary cystatin C and ß2-microglobulin concentrations, the markers of renal tubular injury. CONCLUSION: Collectively, these data signify the binary profit of tangeretin: enhancement of renal protective mechanisms against cisplatin and attenuation of renal tubular cell injuries induced by the agent.

Genome Engineering for Stem Cell Transplantation.

To avoid the ethical issues of embryonic stem cells, genome engineering has focused on inducible pluripotent stem cells, which can develop into all 3 germ layers. The ability to detect methylation patterns in these cells allows research into pluripotency markers. The recently developed CRISPR system has allowed widespread application of genome engineering techniques. The CRISPR-Cas9 system, a potent system for genome editing, can be used for gene knockout or knock-in genome manipulations through substitution of a target genetic sequence with a desired donor sequence. Two types of genome engineering can be initiated: homologous or nonhomologous DNA repair by the Cas9 nuclease. Delivery of the CRISPR-Cas9 and target donor vectors in human pluripotent stem cells can be accomplished via viral and nonviral delivery methods. Nonviral delivery includes lipid-mediated transfection and electroporation. It has become the most common and efficient in vitro delivery method for human pluripotent stem cells. The CRISPR-Cas9 system can be combined with inducible pluripotent stem cells to generate single or multiple gene knockouts, correct mutations, or insert reporter transgenes. Knockouts can also be utilized to investigate epigenetic roles and targets, such as investigation of DNA methylation. CRISPR could be combined with human pluripotent stem cells to explore genetic determinants of lineage choice, differentiation, and stem cell fate, allowing investigators to study how various genes or noncoding elements contribute to specific processes and pathways. The CRISPR-Cas9 system can also be used to create null or nucleasedead Cas9, which has no enzymatic activity but has been utilized through fusion with other functional protein domains. In conclusion, RNA-guided genome targeting will have broad implications for synthetic biology, direct perturbation of gene networks, and targeted ex vivo and in vivo gene therapy.

Anti-HLA Antibody: The Role of Epitopes in Organ Transplantation.

Recent developments have been achieved for better matching in solid-organ transplantation by epitope matching. HLA matching remains a standard immunologic strategy to determine organ compatibility for recipients. Advancements in tissue typing have introduced HLA matching at the epitope level. For this, B cells are able to recognize polymorphic amino acid configurations, which are named epitopes. However, antibody production against these epitopes may be a leading cause of rejection. Although data to support the added clinical benefit of epitope matching over traditional antigen matching are still lacking, there are at least 2 theoretical reasons for epitope matching: (1) to avoid future allosensitization with the development of anti-HLA antibodies and (2) to allow selection of a suitable allograft for highly sensitized patients through virtual crossmatch. Sensitive antibody tests with a comprehensive panel of single alleles have yielded informative, donor-specific antibody reactivity patterns that can be analyzed with a computer algorithm. This program (HLAMatchmaker) uses structurally defined eplets to describe epitopes that can react with specific antibodies. Although low mean fluorescence intensity levels by Luminex (Austin, TX, USA) assay are usually considered low risk for solid organ transplant, it could be important in posttransplant humoral rejection. Thus, specific shared eplets should always be investigated with respect to previous transplant mismatches. Epitopes are present on a single HLA (private epitope) or shared by multiple antigens (public epitope). The phenomenon of crossreactivity in HLA testing, often explained as crossreactive groups of antigens with antibody, can be clearly explained now by public epitopes, an antibody targeting an epitope that shows positive reaction with all antigens sharing the epitope. A better understanding of the immunogenicity and structural characteristics of HLA epitopes will guide us to consider epitope matching as an important parameter for donor selection in kidney transplant in the near future.

AMPK: A promising molecular target for combating cisplatin toxicities.

Cisplatin is a broadly prescribed anti-tumor agent for the treatment of diverse cancers. Therapy with cisplatin, however, is associated with various adverse effects including nephrotoxicity and ototoxicity. AMP kinase (AMPK), an evolutionarily conserved enzyme, functions as the fundamental regulator of energy homeostasis. While AMPK activation protects normal tissues against cisplatin-induced toxicities, its impact in cancer is context-dependent and there is no single, uniform role for AMPK. On one hand, some report that AMPK activation augments cisplatin-induced apoptosis in cancer, while on the other hand, few reports indicate that AMPK activation rescues cancer cells from the cytotoxicity induced by cisplatin. Here we review the most salient signaling pathways regulated by AMPK with an emphasis on their relation to cisplatin toxicity and yet discuss context-dependent functions of AMPK in cancer.

Reduction of renal tubular injury with a RAGE inhibitor FPS-ZM1, valsartan and their combination in streptozotocin-induced diabetes in the rat.

Receptor for advanced glycation end-products (RAGE) is involved in the pathogenesis of diabetic nephropathy. FPS-ZM1, a selective RAGE inhibitor, in combination with valsartan were investigated for their protective potentials on the renal markers of tubular injury in streptozotocin-induced diabetic rats. Rats were assigned into groups of receiving FPS-ZM1 (1 mg/kg/day), valsartan (100 mg/kg/day), and FPS-ZM1 plus valsartan (1 mg/kg/day and 100 mg/kg/day, respectively) for one month. Kidney histology, renal inflammation and oxidative stress, and renal and urinary markers of tubular injury were investigated. FPS-ZM1 and valsartan in combination more significantly attenuated renal expressions of tumor necrosis factor-alpha and interleukin-6 genes and reduced urinary levels of interleukin-6. Moreover, the combination elevated renal NAD+/NADH ratios and Sirt1 activities, and mitigated nuclear acetylated NF-κB p65 levels. In addition to alleviating indices of oxidative stress i.e. malondialdehyde, superoxide dismutase and glutathione peroxidase, the combination of FPS-ZM1 and valsartan more effectively upregulated the renal levels of master antioxidant proteins Nrf2, heme oxygenase-1, and NAD(P)H:quinone oxidoreductase-1. Additionally, this dual therapy ameliorated more efficiently the indices of renal tubular injuries as indicated by decreased renal kidney injury molecule-1 levels as well as reduced urinary levels of cystatin C, retinol binding protein, and beta-2-microglobulin. While FPS-ZM1 alone had no appreciable effects on the renal fibrosis, the combination treatment ameliorated fibrosis better than valsartan in the kidneys. Collectively, these findings underline the extra benefits of FPS-ZM1 and valsartan dual administrations in obviating the renal tubular cell injury in streptozotocin-induced diabetic rats partly by suppressing renal inflammation and oxidative stress.