Effect of dapagliflozin on the initial estimated glomerular filtration rate dip in chronic kidney disease patients without diabetes mellitus.

BACKGROUND: Dapagliflozin (DAPA), a sodium-glucose transporter 2 inhibitor (SGLT2i), attenuates kidney outcomes in patients with not only diabetes mellitus (DM) but also chronic kidney disease (CKD). SGLT2i-derived initial dip in estimated glomerular filtration rate (eGFR) has been considered to reduce excess glomerular pressure, followed by renal protection in patients with DM. However, whether DAPA confers the eGFR dip and its independent determinants for CKD patients without DM are unclear. METHODS: A total of 126 patients with CKD treated with 10 mg DAPA daily was retrospectively registered. After participants with missing data and DM were excluded, 51 participants were enrolled. RESULTS: An initial eGFR dip was observed 1 month after initiation of DAPA, which was sustained until 2 months. DAPA did not affect urinary protein excretion; however, serum uric acid was decreased, while hemoglobin level was increased. Multiple regression analysis revealed that eGFR at baseline was the only independent determinant of the initial dip of eGFR. The patients currently showing exacerbation of glomerular hyperfiltration exhibited the larger initial eGFR dip rather than those showing progressive renal dysfunction. The patients meeting exclusion criteria of DAPA-CKD trial exhibited same degree of the initial eGFR dip as others. CONCLUSIONS: DAPA causes an initial dip of eGFR in CKD patients without DM at 1 month after starting DAPA treatment. A higher eGFR at baseline predicts a large initial eGFR dip, which might be linked to the subsequent recovery in eGFR in CKD patients without DM.

Prospective nationwide multicentre cohort study of the clinical significance of autoimmune features in idiopathic interstitial pneumonias.

BACKGROUND: Some patients with idiopathic interstitial pneumonia (IIP) show autoimmune features. Interstitial pneumonia with autoimmune features (IPAF) was recently proposed as a research concept in these patients. However, retrospective studies reported conflicting results of its prognosis. Therefore, this study was conducted to prospectively evaluate the clinical significance of autoimmune features in patients with IIP. METHODS: This nationwide multicentre study prospectively enrolled consecutive patients with IIP. At the diagnosis, we systematically evaluated 63 features suggestive of connective tissue diseases using a checklist including symptoms/signs and autoantibodies, which contained most items of the IPAF criteria and followed up with the patients. Clinical phenotypes were included in a cluster analysis. RESULTS: In 376 patients with IIP enrolled, 70 patients (18.6%) met the IPAF criteria. The proportion of patients with IPAF was significantly lower in idiopathic pulmonary fibrosis (IPF) than in non-IPF (6.0% vs 24.3%, respectively). During a median observation period of 35 months, patients with IPAF more frequently developed systemic autoimmune diseases and had less frequent acute exacerbation of IIPs than patients with non-IPAF. IPAF diagnosis was significantly associated with better survival and was an independent positive prognostic factor in total and patients with non-IPF. Cluster analysis by similarity of clinical phenotypes identified a cluster in which there was a higher number of women, and patients had more autoimmune features and a better prognosis than other clusters. INTERPRETATION: These observations suggest that some patients with IIP show autoimmune features with distinct characteristics and favourable prognosis. However, we were not able to determine the appropriate therapies for these patients.

Increased serum cholesterol and long-chain fatty acid levels are associated with the efficacy of nivolumab in patients with non-small cell lung cancer.

BACKGROUND: Lipids have immunomodulatory functions and the potential to affect cancer immunity. METHODS: The associations of pretreatment serum cholesterol and long-chain fatty acids with the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were evaluated in 148 patients with non-small cell lung cancer who received nivolumab. RESULTS: When each lipid was separately evaluated, increased low-density lipoprotein (LDL)-cholesterol (P < 0.001), high-density lipoprotein (HDL)-cholesterol (P = 0.014), total cholesterol (P = 0.007), lauric acid (P = 0.015), myristic acid (P = 0.022), myristoleic acid (P = 0.035), stearic acid (P = 0.028), linoleic acid (P = 0.005), arachidic acid (P = 0.027), eicosadienoic acid (P = 0.017), dihomo-γ-linolenic acid (P = 0.036), and behenic acid levels (P = 0.032) were associated with longer PFS independent of programmed death ligand 1 (PD-L1) expression. Meanwhile, increased LDL-cholesterol (P < 0.001), HDL-cholesterol (P = 0.009), total cholesterol (P = 0.036), linoleic acid (P = 0.014), and lignoceric acid levels (P = 0.028) were associated with longer OS independent of PD-L1 expression. When multiple lipids were evaluated simultaneously, LDL-cholesterol (P = 0.003), HDL-cholesterol (P = 0.036), and lauric acid (P = 0.036) were independently predictive of PFS, and LDL-cholesterol (P = 0.008) and HDL-cholesterol (P = 0.031) were predictive of OS. ORR was not associated with any serum lipid. CONCLUSIONS: Based on the association of prolonged survival in patients with increased serum cholesterol and long-chain fatty acid levels, serum lipid levels may be useful for predicting the efficacy of immune checkpoint inhibitor therapy.

Erlotinib and bevacizumab in elderly patients ≥75 years old with non-small cell lung cancer harboring epidermal growth factor receptor mutations.

The efficacy and safety of combination therapy with erlotinib and bevacizumab in elderly patients with non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) gene mutations are unknown. Elderly patients aged ≥75 years old with advanced or recurrent NSCLC and EGFR mutations (exon 19 deletion or L858R mutation in exon 21) received erlotinib (150 mg, daily) and bevacizumab (15 mg/kg on day 1 of a 21-day cycle) until disease progression or the occurrence of unacceptable toxicities. The primary endpoint was progression-free survival from enrollment. Twenty-five patients were enrolled in this study, and the median age was 80 years. Fifteen (60.0%) and 10 patients (40.0%) had exon 21 L858R mutations and exon 19 deletions, respectively. The median progression-free survival from enrollment was 12.6 months [95% confidence interval (CI): 8.0-33.7 months]. The objective response rate was 88.0% [95% CI: 74.0%-99.0%], and the disease control rate was 100% [95% CI: 88.7%-100%]. Grade 3 or higher adverse events occurred in 12 patients (48.0%), and rash and nausea were the most common. Grade 3 or higher bevacizumab-related toxicities occurred in 4 (16.0%) patients, including proteinuria (n = 2), gastrointestinal perforation (n = 1) and pneumothorax (n = 1). A dose reduction of erlotinib and cessation of bevacizumab was required in 16 (64.0%) and 18 patients (72.0%), respectively. Erlotinib and bevacizumab combination therapy showed a minimal survival benefit with frequent dose reductions and/or treatment discontinuations in elderly patients with EGFR-positive NSCLC.

Screening of Fabry disease in patients with chronic kidney disease in Japan.

BACKGROUND: Fabry disease (FD), an X-linked lysosomal storage disorder caused by a deficiency in alfa-galactosidase A (α-Gal A) activity due to mutations in the GLA gene, has a prevalence of 0-1.69% in patients undergoing haemodialysis; however, its prevalence in patients with chronic kidney disease (CKD) Stages 1-5 is unknown. METHODS: Serum α-Gal A activity analysis and direct sequencing of GLA were used to screen for FD in 2122 male patients with CKD, including 1703 patients with CKD Stage 5D and 419 with CKD Stages 1-5. The correlation between serum α-Gal A activity and confounding factors in patients with CKD Stages 1-5 was evaluated. RESULTS: FD prevalence rates in patients with CKD Stage 5D and CKD Stages 1-5 were 0.06% (1/1703) and 0.48% (2/419), respectively. A patient with CKD Stage 5D exhibited a novel GLA mutation, p.Met208Arg, whereas two patients with CKD Stages 1-5 had c.370delG and p.Met296Ile. p. Met208Arg caused moderate structural changes in the molecular surface region near the substituted amino acid residue but did not affect the catalytic residues Asp170 and Asp231 in α-Gal A. Serum α-Gal A activity in patients with CKD Stages 1-5 was inversely correlated with age (P < 0.0001) but directly correlated with estimated glomerular filtration rate (P < 0.0001). CONCLUSIONS: FD prevalence was much higher in male patients with CKD Stages 1-5 than in those with CKD Stage 5D. FD screening in patients with CKD Stages 1-5 may improve patient survival, decreasing the number of patients with CKD Stage 5D.

Prednisolone and tacrolimus versus prednisolone and cyclosporin A to treat polymyositis/dermatomyositis-associated ILD: A randomized, open-label trial.

BACKGROUND AND OBJECTIVE: The efficacy of combination therapy with corticosteroids and CNI, TAC and CsA, for PM/DM-ILD has been described retrospectively. However, it remains unknown which CNI treatment regimens, TAC or CsA regimens, are more effective as initial treatments for patients with PM/DM-ILD. METHODS: We conducted a prospective multicentre, open-label, randomized, 52-week phase 2 trial. Patients with PM/DM-ILD were randomly allocated to receive PSL plus TAC (TAC group) or PSL plus CsA (CsA group). The primary endpoint was PFS rate in the intention-to-treat population at 52 weeks. The secondary endpoints were OS rate at 52 weeks, changes in pulmonary function tests from baseline to 52 weeks and AE. RESULTS: Fifty-eight patients were randomly assigned to the TAC group (n = 30) and the CsA group (n = 28). The PFS rates at 52 weeks were 87% in the TAC group and 71% in the CsA group (P = 0.16). The OS rates at 52 weeks were 97% in the TAC group and 93% in the CsA group (P = 0.50). The %FVC at 52 weeks in the per-protocol populations significantly increased in both groups. None of the patients discontinued the treatment due to AE. CONCLUSION: PSL plus TAC treatment may achieve a better short-term PFS rate compared with PSL plus CsA treatment. Further studies must be conducted to evaluate the long-term efficacy and safety of such treatment.

Effect of tolvaptan on renal involvement in patients with autosomal dominant polycystic kidney disease according to different gene mutations.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder caused by mutations in the polycystic kidney disease (PKD) gene. Although tolvaptan has benefits for renal involvement, the different effects depending on the gene mutation type are unknown. Thus, we explore the different effects of tolvaptan on the annual changes in total kidney volume (%TKV) and estimated glomerular filtration rate (eGFR) according to the gene mutation type in ADPKD patients. METHODS: In total, 135 ADPKD patients were screened, and 22 patients taking tolvaptan for at least a year were retrospectively studied at the Kurume University Hospital. We examined the decline in renal function and %TKV by computed tomography and analyzed the gene mutation. Patients were classified into the following four groups according to gene mutation type: PKD1-truncated, PKD1-non-truncated, PKD2, and mutation not found. Patients were treated with tolvaptan, and the effects of tolvaptan were analyzed according to the gene mutation type. RESULTS: Patients (age: 52.3 ± 11.2 years) were administered tolvaptan at a dose of 45 or 60 mg. No variation was observed in the annual changes in eGFR (%eGFR) (before: - 10.5% ± 13.9%, after: - 14.4% ± 8.1%, P = 0.139), whereas %TKV was significantly improved after the tolvaptan treatment (before: 14.9% ± 8.0%, after: - 5.4% ± 7.6%, P < 0.001). Unlike %eGFR, tolvaptan treatment significantly improved %TKV, regardless of the type of gene mutation. CONCLUSIONS: A year treatment with tolvaptan significantly improved %TKV in patients with ADPKD, regardless of the gene mutation type.

Pneumothorax in Patients with Idiopathic Pleuroparenchymal Fibroelastosis: Incidence, Clinical Features, and Risk Factors.

BACKGROUND: Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare form of idiopathic interstitial pneumonia that is characterized by predominantly upper lobe pleural and subpleural lung parenchymal fibrosis. Pneumothorax is one of the major respiratory complications in PPFE patients; however, its clinical features are poorly understood. OBJECTIVE: We aimed to investigate the complication of pneumothorax in patients with idiopathic PPFE. METHODS: A retrospective multicenter study involving 89 patients who had been diagnosed with idiopathic PPFE was conducted. We investigated the cumulative incidence, clinical features, and risk factors of pneumothorax after the diagnosis of idiopathic PPFE. RESULTS: Pneumothorax developed in 53 patients (59.6%) with 120 events during the observation period (41.8 ± 35.0 months). The cumulative incidence of pneumothorax was 24.8, 44.9, and 53.9% at 1, 2, and 3 years, respectively. Most events of pneumothorax were asymptomatic (n = 85; 70.8%) and small in size (n = 92; 76.7%); 30 patients (56.6%) had recurrent pneumothorax. Chest drainage was required in 23 pneumothorax events (19.2%), and a persistent air leak was observed in 13 (56.5%). Patients with pneumothorax were predominantly male and frequently had pathological diagnoses of PPFE and prior history of pneumothorax and corticosteroid use; they also had significantly poorer survival than those without pneumothorax (log-rank test; p = 0.001). Multivariate analysis revealed that a higher residual volume/total lung capacity ratio was significantly associated with the development of pneumothorax after the diagnosis. CONCLUSION: Pneumothorax is often asymptomatic and recurrent in patients with idiopathic PPFE, leading to poor outcomes in some cases.

Switch maintenance therapy with S-1 after induction therapy with carboplatin and nanoparticle albumin-bound paclitaxel in advanced lung squamous cell carcinoma.

Background Optimal maintenance therapy for lung squamous cell carcinoma (SCC) has not been established. The aim of this study was to evaluate the efficacy and safety of switch maintenance therapy with S-1, an oral fluoropyrimidine, after induction therapy with carboplatin and nanoparticle albumin-bound paclitaxel (nab-paclitaxel) in chemotherapy-naïve patients with advanced SCC. Methods Chemotherapy-naïve patients with advanced SCC received induction therapy with four cycles of carboplatin (at an area under the curve of 6, day 1 of a 28-day cycle) and nab-paclitaxel (100 mg/kg, days 1, 8, and 15). Patients who achieved disease control after induction therapy received maintenance therapy with S-1 (80 mg/m2, days 1-14 of a 21-day cycle) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) from the start of maintenance therapy. Results Seventy-two patients with SCC were enrolled to the study. After four cycles of induction therapy, 35 (48.6%) patients achieved disease control, and 31 (43.1%) of these patients received maintenance therapy. Median PFS from the start of maintenance therapy was 3.0 months (95% confidence interval: 2.1-3.8 months). The most common toxicities of grade 3 or higher during maintenance therapy were nausea (13.3%), neutropenia (10.0%), and diarrhea (6.7%). Conclusions Switch maintenance therapy with S-1 after induction therapy with carboplatin and nab-paclitaxel was associated with moderate efficacy and acceptable safety and may represent a feasible treatment option for patients with advanced SCC.

Advanced glycation end products evoke inflammatory reactions in proximal tubular cells via autocrine production of dipeptidyl peptidase-4.

We have previously shown that albuminuria and renal levels of advanced glycation end products (AGEs), receptor for AGEs (RAGE), and oxidative stress are suppressed in dipeptidyl peptidase-4 (DPP-4)-deficient diabetic rats, thus suggesting the crosstalk between AGE-RAGE axis and DPP-4 in experimental diabetic nephropathy. Therefore, we examined here the role of DPP-4 in AGE-evoked inflammatory reactions in human proximal tubular cells. Proteins were extracted from proximal tubular cells, and conditioned medium was collected, both of which were subjected to western blot analysis using anti-DPP-4 antibody. RAGE-aptamer was prepared using a systemic evolution of ligands by exponential enrichment. NF-κB p65 and monocyte chemoattractant protein-1 (MCP-1) gene expression was analyzed by reverse transcription-polymerase chain reaction. AGEs significantly increased DPP-4 expression and soluble DPP-4 production by tubular cells, the latter of which was attenuated by RAGE-aptamer or an anti-oxidant, N-acetylcysteine. AGEs or DPP-4 up-regulated NF-κB p65 or MCP-1 mRNA levels in tubular cells, which were suppressed by linagliptin, an inhibitor of DPP-4. AGEs stimulated NF-κB p65 gene expression in tubular cells isolated from control rats, but not from DPP-4-deficient rats. Our present results suggest that the AGE-RAGE-mediated oxidative stress could evoke inflammatory reactions in proximal tubular cells via autocrine production of DPP-4.

Compared effects of calcium and sodium polystyrene sulfonate on mineral and bone metabolism and volume overload in pre-dialysis patients with hyperkalemia.

BACKGROUND: Hyperkalemia is prevalent in end-stage renal disease patients, being involved in life-threatening arrhythmias. Although polystyrene sulfonate (PS) is commonly used for the treatment of hyperkalemia, direct comparison of effects between calcium and sodium PS (CPS and SPS) on mineral and bone metabolism has not yet been studied. METHODS: In a randomized and crossover design, 20 pre-dialysis patients with hyperkalemia (>5 mmol/l) received either oral CPS or SPS therapy for 4 weeks. RESULTS: After 4-week treatments, there was no significant difference of changes in serum potassium (K) from the baseline (ΔK) between the two groups. However, SPS significantly decreased serum calcium (Ca) and magnesium (Mg) and increased intact parathyroid hormone (iPTH) values, whereas CPS reduced iPTH. ΔiPTH was inversely correlated with ΔCa and ΔMg (r = -0.53 and r = -0.50, respectively). Furthermore, sodium (Na) and atrial natriuretic peptide (ANP) levels were significantly elevated in patients with SPS, but not with CPS, whereas ΔNa and ΔANP were significantly correlated with each other in all the patients. We also found that ΔNa and Δ(Na to chloride ratio) were positively correlated with ΔHCO3-. In artificial colon fluid, CPS increased Ca and decreased Na. Furthermore, SPS greatly reduced K, Mg, and NH3. CONCLUSION: Compared with SPS, CPS may be safer for the treatment of hyperkalemia in pre-dialysis patients, because it did not induce hyperparathyroidism or volume overload.

Asymmetric Dimethylarginine Contributes to the Impaired Response to Erythropoietin in CKD-Anemia.

Erythropoietin-resistant anemia is associated with adverse cardiovascular events in patients with ESRD, but the underlying mechanism remains unclear. Here, we evaluated the role of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA). In 54 patients with advanced CKD, erythrocyte but not plasma ADMA levels independently associated with low hemoglobin values, although levels of both types of ADMA were elevated compared with those in healthy volunteers. Furthermore, erythrocyte ADMA level associated with the erythropoietin resistance index in patients receiving a weekly injected dose of erythropoiesis-stimulating agents standardized for hemoglobin levels and body weight, whereas it correlated with the erythropoietin demand index (plasma erythropoietin units divided by the hemoglobin value) in patients not receiving erythropoiesis-stimulating agents. Compared with sham-operated controls, wild-type mice with 5/6 subtotal nephrectomy (Nx), a remnant kidney model with advanced CKD, had decreased hemoglobin, hematocrit, and mean corpuscular volume values but increased erythrocyte and plasma ADMA and plasma erythropoietin levels. In comparison, dimethylarginine dimethlaminohydrolase-1 transgenic (DDAH-1 Tg) mice, which efficiently metabolized ADMA, had significant improvements in all of the values except those for erythropoietin after 5/6 Nx. Additionally, wild-type Nx mice, but not DDAH-1 Tg Nx mice, had reduced splenic gene expression of erythropoietin receptor and erythroferrone, which regulates iron metabolism in response to erythropoietin. This study suggests that erythrocyte ADMA accumulation contributes to impaired response to erythropoietin in predialysis patients and advanced CKD mice via suppression of erythropoietin receptor expression.

L-Carnitine Supplementation Improves Self-Rating Depression Scale Scores in Uremic Male Patients Undergoing Hemodialysis.

BACKGROUND: Depression is highly prevalent in uremic patients undergoing hemodialysis (HD). We previously found that low free-carnitine levels are associated with depression severity in male patients undergoing HD. However, whether L-carnitine supplementation improves the depression state in male patients undergoing HD remains unclear. METHODS: Sixteen male patients undergoing HD were orally administered 900 mg L-carnitine daily or intravenously administered 1000 mg L-carnitine immediately after undergoing HD for 3 months. The depression state and various types of carnitine levels were evaluated using the self-rating depression scale (SDS) and tandem mass spectrometry, respectively, at baseline and 3 months after treatment. RESULTS: L-carnitine supplementation significantly increased serum levels of free and other acylcarnitine types, associated with improved SDS scores in male patients undergoing HD. Univariate analysis revealed that low baseline butyryl- and isovaleryl-/2-methylbutyryl-carnitine levels were significantly correlated with SDS scores after treatment. Multiple regression analysis revealed that butyryl-carnitine levels were a sole independent predictor of SDS scores after treatment (r2 = 0.533). CONCLUSION: L-carnitine supplementation for 3 months improved the depression state in uremic male patients undergoing HD. Thus, low butyryl-carnitine levels may predict the clinical response to L-carnitine supplementation in male patients undergoing HD and who have mild depression.

Maternal exposure to high-fat and high-fructose diet evokes hypoadiponectinemia and kidney injury in rat offspring.

BACKGROUND: Maternal exposure to overnutrition during fetal development contributes to metabolic and renal damage in offspring. Adiponectin plays a protective role against obesity-related renal injury. However, role of adiponectin in renal injury of offspring exposed to maternal overnutrition remains unknown. We addressed the issue. METHODS: Female Sprague-Dawley rats were fed either a standard (N) or a high-fat and high-fructose (HFF)-diet for 6 weeks before mating, and kept each diet during the gestation and lactation period. After 4 weeks postpartum, all the offspring were fed N diet, and followed by 12 weeks. Kidney weight, urinary albumin excretion, blood pressure, and blood chemistry, including adiponectin and malondialdehyde, a marker of oxidative stress, were evaluated in the offspring. RESULTS: Compared with N-offspring, serum adiponectin levels of 1-day- and 4-week-old HFF-offspring were significantly lower, the latter of which was inversely associated with malondialdehyde. Kidney weight was significantly decreased in 1-day-old HFF-offspring, whereas increased in 4-week-old HFF-offspring. Urinary albumin excretion levels of HFF-offspring at 8, 12, and 16-week old were significantly higher than those of N-offspring at the same age, whose levels at 16-week old were inversely correlated with plasma adiponectin. Compared with N-offspring, HFF-offspring at 16-week old exhibited glomerulosclerosis, hyperglycemia, and high mean blood pressure associated with reduced podocin and increased transforming growth factor-ß1 expression in the kidneys. CONCLUSIONS: Our present study suggests that exposure to maternal HFF-diet during fetal and early postnatal development induces hypoadiponectinemia in offspring, which might cause renal injury and metabolic derangements later in life.

Oral L-carnitine supplementation increases trimethylamine-N-oxide but reduces markers of vascular injury in hemodialysis patients.

OBJECTIVES: Food or supplement-derived L-carnitine is changed to trimethylamine (TMA) by interstinal microbiota, which is further metabolized to trimethylamine-N-oxide (TMAO), being involved in the promotion of atherosclerosis in animal models. Meanwhile, carnitine deficiency has played a role in accelerated atherosclerosis in hemodialysis (HD) patients. However, effects of oral L-carnitine supplementation on circulating levels of TMAO and markers of vascular injury and oxidative stress in patients on HD remain unclear. In this study, we addressed the issue. METHODS: Thirty-one HD patients with carnitine deficiency were treated with oral L-carnitine (900 mg/d) for 6 months. At baseline and after treatment, clinical variables including circulating levels of carnitine fractions, TMA, TMAO, advanced glycation end products (AGE), soluble forms of intracellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), and malondialdehyde (MDA) were measured. RESULTS: Oral L-carnitine supplementation significantly increased total, free, acyl carnitine, and plasma TMA and TMAO levels, whereas it decreased markers of vascular injury and oxidative stress such as sICAM-1, sVCAM-1, and MDA levels. TMA and TMAO levels at baseline were correlated with each other, and free carnitine was independently associated with TMAO levels. Furthermore, change in AGE values from baseline ([INCREMENT]AGE) was positively correlated with [INCREMENT]sICAM-1 (P = 0.043) and was a sole independent determinant of [INCREMENT]sICAM-1 (R = 0.133, P = 0.043). CONCLUSIONS: This study demonstrated that although oral L-carnitine supplementation was associated with increased TMAO levels, it might be beneficial on vascular injury in patients on HD. Vasculoprotective properties of L-carnitine supplementation in HD patients might be ascribed partly to its inhibitory actions on AGE.

Asymmetric dimethylarginine accumulates in the kidney during ischemia/reperfusion injury.

Ischemia/reperfusion injury is the leading cause of acute tubular necrosis. Nitric oxide has a protective role against ischemia/reperfusion injury; however, the role of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, in ischemia/reperfusion injury remains unclear. ADMA is produced by protein arginine methyltransferase (PRMT) and is mainly degraded by dimethylarginine dimethylaminohydrolase (DDAH). Here we examined the kinetics of ADMA and PRMT and DDAH expression in the kidneys of ischemia/reperfusion-injured mice. After the injury, DDAH-1 levels were decreased and renal and plasma ADMA values were increased in association with renal dysfunction. Renal ADMA was correlated with 8-hydroxy-2'-deoxyguanosine, a marker of oxidative stress. An antioxidant, N-acetylcysteine, or a proteasomal inhibitor, MG-132, restored these alterations. Infusion of subpressor dose of ADMA exacerbated renal dysfunction, capillary loss, and tubular necrosis in the kidneys of ischemia/reperfusion-injured wild mice, while damage was attenuated in DDAH transgenic mice. Thus, ischemia/reperfusion injury-induced oxidative stress may reduce DDAH expression and cause ADMA accumulation, which may contribute to capillary loss and tubular necrosis in the kidney.

Protective role of JAK/STAT signaling against renal fibrosis in mice with unilateral ureteral obstruction.

Inflammation is involved in renal fibrosis, a final common pathway for kidney diseases. To clarify how JAK/STAT/SOCS system was involved in renal fibrosis, UUO was induced in BALB/c or SOCS3(+/-) mice in the presence or absence of JAK inhibitor-incorporated nanoparticle (pyridine6-PGLA). UUO increased pSTAT3 and subsequently elevated SOCS3 levels in the obstructed kidneys. pSTAT3 levels were further increased in SOCS3(+/-) mice. UUO-induced renal fibrosis was markedly suppressed in SOCS3(+/-) mice, while it was aggravated by pre-treatment with pyridine6-PGLA. Although there were no differences in renal mRNA levels of TGF-ß and collagens between wild and SOCS3(+/-) mice, MMP-2 activity was enhanced in SOCS3(+/-) UUO mice. Activated MMP-2 was completely suppressed by pyridine6-PGLA-pre-treatment. TNF-α one of JAK/STAT activators, increased pSTAT3 levels and subsequently induced MMP-2 activation in proximal tubular cells. These results suggest that JAK/STAT3 signaling may play a role in repair process of renal fibrosis in UUO partly via MMP-2 activation.

Carnitine deficiency is associated with late-onset hypogonadism and depression in uremic men with hemodialysis.

Late-onset hypogonadism (LOH) and depression contribute to cardiovascular disease (CVD) in male hemodialysis (HD) patients. Carnitine deficiency is frequently observed in HD patients, playing a role in CVD. We examined whether carnitine deficiency was independently associated with LOH and depression in these patients. Twenty-six male HD patients underwent determinations of serum levels of free carnitine and testosterone. Status of LOH and depression were evaluated by questionnaires using aging male symptoms' (AMS) scale and self-rating depression scale (SDS), respectively. Free carnitine and testosterone levels in male HD patients were significantly lower than those in age-matched healthy male subjects. Linear regression analysis showed that AMS scale was positively associated with SDS. Univariate regression analysis revealed that total carnitine (inversely), free carnitine (inversely) and HD duration were correlated with AMS scale. Multiple stepwise regression analysis revealed that free carnitine was an independent determinant of AMS scale. Furthermore, free carnitine was also independently correlated with SDS in male HD patients. This study demonstrated that decreased free carnitine levels were independently associated with AMS scale and SDS in male HD patients. The observations suggest that decreased free carnitine levels could be a marker and therapeutic target of LOH and depression in uremic men with HD.