Preventive effects of vasohibin-2-targeting peptide vaccine for diabetic nephropathy.

Diabetic nephropathy remains the leading cause of end-stage kidney disease in many countries, and additional therapeutic targets are needed to prevent its development and progression. Some angiogenic factors are involved in the pathogenesis of diabetic nephropathy. Vasohibin-2 (VASH2) is a novel proangiogenic factor, and our previous study showed that glomerular damage is inhibited in diabetic Vash2 homozygous knockout mice. Therefore, we established a VASH2-targeting peptide vaccine as a tool for anti-VASH2 therapy in diabetic nephropathy. In this study, the preventive effects of the VASH2-targeting peptide vaccine against glomerular injury were examined in a streptozotocin (STZ)-induced diabetic mouse model. The mice were subcutaneously injected with the vaccine at two doses 2 wk apart and then intraperitoneally injected with 50 mg/kg STZ for 5 consecutive days. Glomerular injury was evaluated 20 wk after the first vaccination. Treatment with the VASH2-targeting peptide vaccine successfully induced circulating anti-VASH2 antibody without inflammation in major organs. Although the vaccination did not affect blood glucose levels, it significantly prevented hyperglycemia-induced increases in urinary albumin excretion and glomerular volume. The vaccination did not affect increased VASH2 expression but significantly inhibited renal angiopoietin-2 (Angpt2) expression in the diabetic mice. Furthermore, it significantly prevented glomerular macrophage infiltration. The preventive effects of vaccination on glomerular injury were also confirmed in db/db mice. Taken together, the results of this study suggest that the VASH2-targeting peptide vaccine may prevent diabetic glomerular injury in mice by inhibiting Angpt2-mediated microinflammation.NEW & NOTEWORTHY This study demonstrated preventive effects of VASH2-targeting peptide vaccine therapy on albuminuria and glomerular microinflammation in STZ-induced diabetic mouse model by inhibiting renal Angpt2 expression. The vaccination was also effective in db/db mice. The results highlight the importance of VASH2 in the pathogenesis of early-stage diabetic nephropathy and the practicability of anti-VASH2 strategy as a vaccine therapy.

Effect of Low-Density Lipoprotein Apheresis on Quality of Life in Patients with Diabetes, Proteinuria, and Hypercholesterolemia.

INTRODUCTION: Treating diabetic nephropathy with low-density lipoprotein (LDL) apheresis reduces proteinuria and improves prognosis. However, its impact on patients' quality of life (QoL) is unclear. This study evaluated the effect of LDL apheresis on QoL in patients with diabetes, proteinuria, and hypercholesterolemia. METHODS: In this nationwide multicenter prospective study, we enrolled 40 patients with diabetes. Inclusion criteria were proteinuria (defined as an albumin/creatinine ratio ≥3 g/g), serum creatinine levels <2 mg/dL, and serum LDL ≥120 mg/dL despite drug treatment. LDL apheresis was performed 6-12 times within 12 weeks. The 36-item Short Form Health Survey (SF-36) was used to analyze QoL. RESULTS: The study enrolled 35 patients (27 men and 8 women; mean age 58.9 ± 11.9 years). A comparison of baseline SF-36 values with those at the end of the course of apheresis found an improvement in the mean physical component summary (37.9 ± 11.4 vs. 40.6 ± 10.5, p = 0.051) and a significant increase in the mean mental component summary (MCS) (49.4 ± 8.4 vs. 52.5 ± 10.9, p = 0.026). A multivariable linear regression analysis revealed a history of coronary heart disease negatively correlated with the MCS increase at the end of the course of apheresis (ß coefficient -6.935, 95% confidence interval, 13.313 to-0.556, p = 0.034). CONCLUSION: Our results suggest that LDL apheresis may improve the mental and physical QoL in patients with diabetes, proteinuria, and hypercholesterolemia.

Vasohibin-1 has α-tubulin detyrosinating activity in glomerular podocytes.

Podocytes are highly specialized epithelial cells in glomeruli, with a complex morphology composed of a cell body, primary processes, and foot processes, which maintain barrier function in glomerular filtration. The microtubule-based cytoskeleton is necessary for podocyte morphology. Microtubule structure and function can be affected by post-translational modification of tubulin, including detyrosination. Recent studies have shown that vasohibin-1 (VASH1), an antiangiogenic factor, has tubulin carboxypeptidase activity that causes detyrosination of α-tubulin. We aimed to examine the role of VASH1 in regulating α-tubulin detyrosination in podocytes and the potential involvement of VASH1 deficiency in renal morphology. In normal mouse kidneys, detyrosinated α-tubulin was mainly identified in glomeruli, especially in podocytes; meanwhile, in cultured immortalized podocytes, α-tubulin detyrosination was promoted with cell differentiation. Notably, α-tubulin detyrosination in glomeruli was diminished in Vash1 homozygous knockout (Vash1-/-) mice, and knockdown of VASH1 in cultured podocytes prevented α-tubulin detyrosination. Although VASH1 deficiency-induced downregulation of detyrosination caused no remarkable glomerular lesions, urinary albuminuria excretion and glomerular volume were significantly higher in Vash1-/- mice than in wild-type mice. Furthermore, decreased glomerular nephrin expression and narrower slit diaphragms width were observed in Vash1-/- mice. Taken together, we demonstrated that α-tubulin detyrosination in podocytes was mainly regulated by VASH1 and that VASH1 deficiency-mediated decreases in α-tubulin detyrosination led to minor alterations in podocyte morphology and predisposition to albuminuria. VASH1 expression and α-tubulin detyrosination may be novel targets for maintaining glomerular filtration barrier integrity.

Renal capsular vein thrombosis.

A 30-year-old pregnant woman developed postpartum HELLP syndrome. Abdominal computed tomography revealed a high-density vessel structure in contact with the right kidney and connected to the right ovarian vein, suggesting thrombosis in the right inferior renal capsular vein (RCV). RCV thrombosis is a rare thrombotic disorder in postpartum women, and hypercoagulability related to the pregnancy complications may be the predisposing factor. The potential risk for pulmonary embolism in the rare pregnancy-related thrombosis should be recognized.

Effects of LDL apheresis on proteinuria in patients with diabetes mellitus, severe proteinuria, and dyslipidemia.

BACKGROUND: Patients with diabetes mellitus and severe proteinuria present with poor renal prognoses, despite improvements in diabetes and kidney disease therapies. In this study, we designed a low-density lipoprotein (LDL)-cholesterol apheresis treatment for patients with diabetic nephropathy (DN)/diabetic kidney disease and severe proteinuria. This was a multicenter prospective LICENSE study to confirm the impact of LDL apheresis on proteinuria that exhibited hyporesponsiveness to treatment. In addition, we sought to determine the efficacy and safety of LDL apheresis by comparing the outcomes to those of historical controls in patients with diabetes, refractory hypercholesterolemia, and severe proteinuria. METHODS: This was a prospective, multicenter study, including 40 patients with diabetes, severe proteinuria, and dyslipidemia. LDL apheresis was performed 6-12 times over a 12-week period. The primary endpoint was the proportion of patients with a decrease in proteinuria excretion of at least 30% in the 6 months after starting therapy. The secondary endpoints included serum creatinine levels and laboratory variables, which were evaluated 4, 6, 12, 18, and 24 months after therapy initiation. RESULTS: LDL apheresis was performed on 40 registered patients with diabetes. The proportion of cases in which proteinuria decreased by 30% or more after 6 months of LDL apheresis was 25%, which was similar to that of historical controls. The overall survival and end-stage kidney disease-free survival rates were significantly higher in the LICENSE group compared to those in historical controls. CONCLUSION: Our results suggest that LDL apheresis may be effective and safe for patients with diabetes, proteinuria, and dyslipidemia. TRIAL REGISTRATION: Trial registration number: jRCTs042180076.

Successful deceased donor kidney transplantation to a recipient with a history of COVID-19 treatment.

CASE PRESENTATION: A 49-year-old Asian male, who had undergone hemodialysis for >16 years, complained of a fever, dysgeusia and dysosmia, and was diagnosed with COVID-19 pneumonia based on severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (SARS-CoV-2 PCR) and computed tomography (CT). Treatment was started with oral favipiravir and ciclesonide inhalation. On the 10th day of treatment, the patient had a persistent high fever and a chest CT showed exacerbation of pneumonia, so dexamethasone was intravenously started. He was discharged after confirming two consecutive negative SARS-CoV-2 PCR tests. Three months after COVID-19 treatment, a SARS-CoV-2 PCR test was negative and he underwent a deceased donor kidney transplantation. Basiliximab induction with triple drug immunosuppression consisting of extended-release tacrolimus, mycophenolate mofetil and prednisolone, which is our regular immunosuppression protocol, was used. He was discharged on postoperative day 18 without the need for postoperative hemodialysis or any complications. The serum creatinine level was 1.72 mg/dL 95 days postoperatively and he had a favorable clinical course that was similar to deceased donor kidney recipients without a history of SARS-CoV-2 infection. CONCLUSION: We report the first case of a kidney transplantation after COVID-19 treatment in Japan and the fourth case globally. We would like to provide information about our successful case due to the anticipated increase in similar candidates in the near future.

Presence of decoy cells for 6 months on urine cytology efficiently predicts BK virus nephropathy in renal transplant recipients.

OBJECTIVES: To investigate the association between duration of consecutive presence of decoy cells on urine cytology and BK virus nephropathy after kidney transplantation. METHODS: In total, 121 kidney transplant recipients were retrospectively evaluated. The best duration of consecutive presence of decoy cells that could be used to predict BK virus nephropathy was analyzed using the area under the curve for each duration, and recipients were divided into two groups based on the best predictive performance. The effectiveness of SV40 immunostaining on urinary cytology was also analyzed. RESULTS: In total, 2534 urine specimens as well as SV40 immunostaining in 2241 urine specimens were analyzed. Six consecutive months of decoy cell positivity had the best predictive performance for BK virus nephropathy (area under the curve = 0.832). The incidence of BK virus nephropathy in recipients with positive decoy cells for 6 months or more consecutive months (5/44) was significantly higher than in those who had positive decoy cells for less than 6 months (0/77; P = 0.005). Decoy cell positivity had a sensitivity, specificity, positive predictive value, and negative predictive value for BK virus nephropathy of 100%, 66%, 11%, and 100% respectively. SV40 immunostaining provided slightly better specificity (68%) and positive predictive value (12%). CONCLUSIONS: The detection of decoy cells at 6 months or more on urine cytology had high predictive value for BK virus nephropathy in kidney transplant recipients. SV40 immunostaining on urine cytology added minimal diagnostic accuracy.

Robotic Renal Autotransplantation: A Feasibility Study in a Porcine Model.

We investigated the feasibility of robotic renal autotransplantation (RAT) in a porcine model to reduce invasiveness of RAT. Five pigs underwent robotic RAT using the da Vinci® robotic system. A robotic left nephrectomy was performed in all cases. Robotic RAT was performed on the left side in all but one case. Four ports were used. In 3 cases, the kidney was taken out through the GelPort® and irrigated on ice with Ringer's solution. In 2 cases, a complete intracorporeal robotic RAT was performed. An end-to-side anastomosis was performed between the renal vein and the external iliac vein and between the renal artery and the external iliac artery. Ureteroneocystostomy was also performed in 2 cases. All cases were performed robotically without open conversion. The median (IQR) console time was 3.1 (0.7) h, and the operative time was 3.8 (1.1) h. The estimated blood loss was 30 (0) ml. The warm ischemia time was 4.0 (0.2) min, and the cold ischemia time was 97 (17) min. Intracorporeal transarterial hypothermic renal perfusion was feasible in the 2 complete intracorporeal robotic RAT cases by using a perfusion catheter through a laparoscopic port. Robotic RAT has the potential to be a new minimally invasive substitute for conventional open surgery.

Low-dose rituximab induction therapy is effective in immunological high-risk renal transplantation without increasing cytomegalovirus infection.

OBJECTIVES: To analyze the effect and impact of low-dose rituximab induction therapy on cytomegalovirus infection in living-donor renal transplantation. METHODS: A total of 92 recipients undergoing living-donor renal transplantation at Okayama University Hospital from May 2009 to August 2018 were evaluated retrospectively. Indications for preoperative rituximab (200 mg/body) were the following: (i) ABO major mismatch; (ii) ABO minor mismatch; (iii) donor-specific anti-human leukocyte antigen antibody-positive; and (iv) focal segmental glomerulosclerosis. We excluded four recipients who were followed <3 months, five who received >200 mg/body rituximab and seven who received prophylactic therapy for cytomegalovirus. RESULTS: There were 59 patients in the rituximab group and 17 in the non-rituximab group. Groups differed significantly in age (median age 53 vs 37 years, respectively; P = 0.04), but not in sex (male 64% vs 65%, P = 1.00), focal segmental glomerulosclerosis (3% vs 0%, P = 1.00) or percentage of cytomegalovirus-seronegative recipients of renal allografts from cytomegalovirus-seropositive donors (12% vs 18%, P = 0.68). The estimated glomerular filtration rate did not differ significantly between groups until 24 months after transplantation. Cytomegalovirus clinical symptoms (10% vs 24%, P = 0.22), including fever ≥38°C (5% vs 12%, P = 0.31) and gastrointestinal symptoms (5% vs 12%, P = 0.31), and the 5-year survival rates of death-censored graft loss (90% vs 83%, P = 0.43) did not differ significantly between groups. CONCLUSIONS: Low-dose rituximab induction therapy is effective in immunological high-risk recipients without increasing cytomegalovirus infection in the absence of valganciclovir prophylaxis.

Genetic Deletion of Vasohibin-2 Exacerbates Ischemia-Reperfusion-Induced Acute Kidney Injury.

Acute kidney injury (AKI) has been increasingly recognized as a risk factor for transition to chronic kidney disease. Recent evidence suggests that endothelial damage in peritubular capillaries can accelerate the progression of renal injury. Vasohibin-2 (VASH2) is a novel proangiogenic factor that promotes tumor angiogenesis. However, the pathophysiological roles of VASH2 in kidney diseases remain unknown. In the present study, we examined the effects of VASH2 deficiency on the progression of ischemia-reperfusion (I/R) injury-induced AKI. I/R injury was induced by bilaterally clamping renal pedicles for 25 min in male wild-type (WT) and Vash2 homozygous knockout mice. Twenty-four hours later, I/R injury-induced renal dysfunction and tubular damage were more severe in VASH2-deficient mice than in WT mice, with more prominent neutrophil infiltration and peritubular capillary loss. After induction of I/R injury, VASH2 expression was markedly increased in injured renal tubules. These results suggest that VASH2 expression in renal tubular epithelial cells might be essential for alleviating I/R injury-induced AKI, probably through protecting peritubular capillaries and preventing inflammatory infiltration.

Renal tubular injury exacerbated by vasohibin-1 deficiency in a murine cisplatin-induced acute kidney injury model.

Acute kidney injury (AKI) is frequently encountered in clinical practice, particularly secondarily to cardiovascular surgery and administration of nephrotoxic agents, and is increasingly recognized for initiating a transition to chronic kidney disease. Clarifying the pathogenesis of AKI could facilitate the development of novel preventive strategies, because the occurrence of hospital-acquired AKI is often anticipated. Vasohibin-1 (VASH1) was initially identified as an antiangiogenic factor derived from endothelial cells. VASH1 expression in endothelial cells has subsequently been reported to enhance cellular stress tolerance. Considering the importance of maintaining peritubular capillaries in preventing the progression of AKI, the present study aimed to examine whether VASH1 deletion is involved in the pathogenesis of cisplatin-induced AKI. For this, we injected male C57BL/6J wild-type (WT) and VASH1 heterozygous knockout (VASH1+/-) mice intraperitoneally with either 20 mg/kg cisplatin or vehicle solution. Seventy-two hours after cisplatin injection, increased serum creatinine concentrations and renal tubular injury accompanied by apoptosis and oxidative stress were more prominent in VASH1+/- mice than in WT mice. Cisplatin-induced peritubular capillary loss was also accelerated by VASH1 deficiency. Moreover, the increased expression of ICAM-1 in the peritubular capillaries of cisplatin-treated VASH1+/- mice was associated with a more marked infiltration of macrophages into the kidney. Taken together, VASH1 expression could have protective effects on cisplatin-induced AKI probably by maintaining the number and function of peritubular capillaries.

Capnocytophaga canimorsus peritonitis diagnosed by mass spectrometry in a diabetic patient undergoing peritoneal dialysis: a case report.

BACKGROUND: Bacterial peritonitis is a serious complication of patients undergoing peritoneal dialysis (PD). Although the identification of causative organisms and use of appropriate antibiotics are essential for treatment, rare and fastidious bacteria are sometimes difficult to detect by conventional biochemical assays. Capnocytophaga canimorsus is a fastidious and slow-growing bacterium that forms a part of the normal oral flora of dogs and cats and is extremely rare as a peritonitis-causing organism. This report demonstrates the usefulness of a mass spectrometry-based technique in identifying such a rare organism in PD-related peritonitis and discusses the diagnosis and treatment of C. canimorsus peritonitis. CASE PRESENTATION: A 49-year-old woman with type 2 diabetes mellitus underwent PD for two years. Repeated exit-site infections led to subcutaneous pathway diversion two months ago. She was hospitalized with fever and abdominal pain as well as cloudy dialysis effluent. Laboratory data revealed increased serum C-reactive protein level and white blood cell (WBC) count in the effluent. Her exit site had no sign of infection, leading to the diagnosis of PD-related peritonitis. Initial therapy with intraperitoneal ceftazidime immediately ameliorated her symptoms, and the WBC count in the effluent normalized in five days. Culture test results of the dialysis effluent on admission were negative with no information regarding the infection route. However, mass spectrometry (MALDI Biotyper, Bruker Daltonics) successfully obtained the specific spectral pattern for C. canimorsus. She had four cats in her house and was advised not to allow the cats in the room where the bag exchange took place. CONCLUSIONS: C. canimorsus is a rare cause of peritonitis in PD patients and is usually susceptible to intraperitoneal third-generation cephalosporins. This mass spectrometry-based bacterial identification method could provide more opportunities to identify uncommon causes and promote appropriate antibiotics therapy in PD-related peritonitis.

Contrast-enhanced Computed Tomography-Guided Percutaneous Cryoablation of Renal Cell Carcinoma in a Renal Allograft: First Case in Asia.

Nephron-sparing treatment should be offered whenever possible to avoid dialysis in allograph cases. Cryoablation is a new treatment option for treating small-sized renal cell cancer (RCCs). We report a case of RCC arising in a kidney allograft treated by cryoablation. To our knowledge, this is the first case in Asia of RCC in a renal allograft treated using cryoablation. Contrast-enhanced CT-guided percutaneous renal needle biopsy and cryoablation were used to identify the RCC, which could not be identified by other techniques. The postoperative course was uneventful. Contrast-enhanced CT also showed no recurrence or metastases at the 6-month follow-up.

Estrogen-related receptor α is essential for maintaining mitochondrial integrity in cisplatin-induced acute kidney injury.

Acute kidney injury (AKI) has been associated with not only higher in-hospital mortality but also the subsequent development of chronic kidney disease (CKD). Recent evidence has suggested the involvement of mitochondrial dysfunction and impaired dynamics in the pathogenesis of AKI. Estrogen-related receptor α (ERRα) is an orphan nuclear receptor that acts as a transcription factor to regulate the transcription of genes required for mitochondrial biogenesis and oxidative phosphorylation. In the present study, we examined the effects of ERRα deficiency on the progression of AKI induced by cisplatin. Male C57BL/6 J wild-type and ERRα-/- mice received a single intraperitoneal injection of 20 mg/kg cisplatin. Seventy-two hours after the injection, kidney function and morphology were evaluated. ERRα expression was observed in renal tubules, and cisplatin inhibited its translocation into nuclei. ERRα deficiency exacerbated cisplatin-induced renal dysfunction and tubular injury, as well as oxidative stress and apoptosis. ERRα-/- mice kidneys revealed lower mitochondrial DNA content and swollen mitochondria with reduced cristae. In addition, these mice had lower expression of the mitochondrial fusion protein mitofusin-2. The cisplatin-induced decrease in mitochondrial DNA and altered mitochondrial structure were more severe in ERRα-/- mice. In cultured mouse proximal tubular epithelial cells, the ERRα inverse agonist XCT-790 significantly inhibited mitofusin-2 expression and induced mitochondrial fragmentation. Taken together, our findings suggest the involvement of ERRα in the progression of cisplatin-induced AKI probably through impaired mitochondrial dynamics.

Renal expression of trefoil factor 3 mRNA in association with tubulointerstitial fibrosis in IgA nephropathy.

AIM: Trefoil factor 3 (TFF3) is a small peptide that is involved in mucosal protection. TFF3 is widely expressed in multiple tissues including kidney tissue. Previous studies have reported that the levels of urinary TFF3 are significantly increased in patients with chronic kidney disease. The aim of this study is to detect the TFF3 mRNA in kidney and elucidate the relationship between renal TFF3 mRNA and tubulointerstitial fibrosis in IgA nephropathy (IgAN). METHODS: We investigated the renal mRNA expression of TFF3 by real-time PCR analysis in biopsy specimens from patients with IgAN, other glomerulonephritis (OGN) and minor glomerular abnormalities (MGA). We also determined the renal localization of TFF3 and the levels of urinary TFF3 by immunostaining and ELISA, respectively. RESULTS: The renal TFF3 mRNA expression was significantly associated with the urinary TFF3 secretion and the tubulointerstitial fibrosis score in the IgAN group alone. Immunostaining of the renal specimen of IgAN patients revealed that TFF3 is located in the renal tubular epithelial cells. The locations were almost the same as those that showed uromodulin positivity; specifically, the thick ascending limb (TAL) of the loop of Henle and the early portion of the distal tubule. The urinary TFF3 levels were positively correlated with the levels of urinary biomarkers of tubulointerstitial injury in such patients. CONCLUSION: Renal TFF3 mRNA is associated with renal tubulointerstitial fibrosis in IgAN patients. The TFF3 located in the renal tubular epithelial cells may play a role in the progression of tubulointerstitial fibrosis in IgAN patients.

Endogenous Antiangiogenic Factors in Chronic Kidney Disease: Potential Biomarkers of Progression.

Chronic kidney disease (CKD) is a major global health problem. Unless intensive intervention is initiated, some patients can rapidly progress to end-stage kidney disease. However, it is often difficult to predict renal outcomes using conventional laboratory tests in individuals with CKD. Therefore, many researchers have been searching for novel biomarkers to predict the progression of CKD. Angiogenesis is involved in physiological and pathological processes in the kidney and is regulated by the balance between a proangiogenic factor, vascular endothelial growth factor (VEGF)-A, and various endogenous antiangiogenic factors. In recent reports using genetically engineered mice, the roles of these antiangiogenic factors in the pathogenesis of kidney disease have become increasingly clear. In addition, recent clinical studies have demonstrated associations between circulating levels of antiangiogenic factors and renal dysfunction in CKD patients. In this review, we summarize recent advances in the study of representative endogenous antiangiogenic factors, including soluble fms-related tyrosine kinase 1, soluble endoglin, pigment epithelium-derived factor, VEGF-A165b, endostatin, and vasohibin-1, in associations with kidney diseases and discuss their predictive potentials as biomarkers of progression of CKD.

An angiotensin II type 1 receptor binding molecule has a critical role in hypertension in a chronic kidney disease model.

Angiotensin II type 1 receptor-associated protein (ATRAP) promotes AT1R internalization along with suppression of hyperactivation of tissue AT1R signaling. Here, we provide evidence that renal ATRAP plays a critical role in suppressing hypertension in a mouse remnant kidney model of chronic kidney disease. The effect of 5/6 nephrectomy on endogenous ATRAP expression was examined in the kidney of C57BL/6 and 129/Sv mice. While 129/Sv mice with a remnant kidney showed decreased renal ATRAP expression and developed hypertension, C57BL/6 mice exhibited increased renal ATRAP expression and resistance to progressive hypertension. Consequently, we hypothesized that downregulation of renal ATRAP expression is involved in pathogenesis of hypertension in the remnant kidney model of chronic kidney disease. Interestingly, 5/6 nephrectomy in ATRAP-knockout mice on the hypertension-resistant C57BL/6 background caused hypertension with increased plasma volume. Moreover, in knockout compared to wild-type C57BL/6 mice after 5/6 nephrectomy, renal expression of the epithelial sodium channel α-subunit and tumor necrosis factor-α was significantly enhanced, concomitant with increased plasma membrane angiotensin II type 1 receptor in the kidneys. Thus, renal ATRAP downregulation is involved in the onset and progression of blood pressure elevation caused by renal mass reduction, and implicates ATRAP as a therapeutic target for hypertension in chronic kidney disease.

Immunohistochemistry of Vasohibin-2 in Human Kidney Disease : Implications in Impaired Glucose Tolerance and Reduced Renal Function.

Several angiogenesis-related factors are known to play important roles in the pathogenesis of kidney disease. Vasohibin-2 (VASH-2) was recently reported as a novel proangiogenic factor. Although VASH-2 was demonstrated to accelerate tumor angiogenesis, its roles in non-tumor processes including renal disease have not been well elucidated yet. Here, we performed a retrospective study including an immunohistochemical analysis of human kidney biopsy specimens from 82 Japanese patients with a variety of kidney diseases, and we evaluated the correlations between the immunoreactivity of VASH-2 and the patients' clinicopathological parameters. VASH-2 immunoreactivity was detected in varying degrees in renal tubules as well as in peritubular capillaries and vasa recta. The cortical and medullary tubule VASH-2+ scores were correlated with the presence of hypertension, and the medullary tubule VASH-2+ score was significantly correlated with the blood glucose (p=0.029, r=0.35) and hemoglobin A1c levels (p=0.0066, r=0.39). Moreover, decreased VASH-2+ scores in the vasa recta were associated with reduced renal function (p=0.0003). These results suggest that VASH-2 could play an important role in the pathogenesis of renal diseases, and that VASH-2 is closely associated with hypertension and impaired glucose tolerance.

The Efficacy of Rituximab in High-risk Renal Transplant Recipients.

Although graft survival following renal transplantation (RTx) has improved, outcomes following highrisk RTx are variable. Preexisting antibodies, including donor-specific antibodies (DSA), play an important role in graft dysfunction and survival. We have designed a study to investigate the safety and efficacy of anti-CD20 monoclonal antibodies (rituximab) in high-risk RTx recipients. Major eligibility criteria include: 1) major and minor ABO blood group mismatch, 2) positive DSA. Thirty-five patients will receive 200 mg/body of rituximab. The primary endpoint is the incidence of B cell depletion. This study will clarify whether rituximab is efficacious in improving graft survival in high-risk RTx recipients.

Uric acid-dependent inhibition of AMP kinase induces hepatic glucose production in diabetes and starvation: evolutionary implications of the uricase loss in hominids.

Reduced AMP kinase (AMPK) activity has been shown to play a key deleterious role in increased hepatic gluconeogenesis in diabetes, but the mechanism whereby this occurs remains unclear. In this article, we document that another AMP-dependent enzyme, AMP deaminase (AMPD) is activated in the liver of diabetic mice, which parallels with a significant reduction in AMPK activity and a significant increase in intracellular glucose accumulation in human HepG2 cells. AMPD activation is induced by a reduction in intracellular phosphate levels, which is characteristic of insulin resistance and diabetic states. Increased gluconeogenesis is mediated by reduced TORC2 phosphorylation at Ser171 by AMPK in these cells, as well as by the up-regulation of the rate-limiting enzymes PEPCK and G6Pc. The mechanism whereby AMPD controls AMPK activation depends on the production of a specific AMP downstream metabolite through AMPD, uric acid. In this regard, humans have higher uric acid levels than most mammals due to a mutation in uricase, the enzyme involved in uric acid degradation in most mammals, that developed during a period of famine in Europe 1.5 × 10(7) yr ago. Here, working with resurrected ancestral uricases obtained from early hominids, we show that their expression on HepG2 cells is enough to blunt gluconeogenesis in parallel with an up-regulation of AMPK activity. These studies identify a key role AMPD and uric acid in mediating hepatic gluconeogenesis in the diabetic state, via a mechanism involving AMPK down-regulation and overexpression of PEPCK and G6Pc. The uricase mutation in the Miocene likely provided a survival advantage to help maintain glucose levels under conditions of near starvation, but today likely has a role in the pathogenesis of diabetes.