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Objective:Evaluating the rate of decline in the estimated glomerular filtration rate (eGFR) may help identify patients with occult chronic kidney disease (CKD). We herein report that eGFR fluctuation complicates the assessment of the rate of decline and propose a long-term eGFR plot analysis as a solution., Methods:In 142 patients with persistent eGFR decline in a single hospital, we evaluated the factors influencing the rate of eGFR decline, calculated over the long term (≥3 years) and short term (, Results:The difference between the rate of eGFR decline calculated using short- and long-term plots increased as the time period considered in the short-term plots became shorter. A regression analysis revealed that eGFR fluctuation was the only factor that explained the difference and that the fluctuation exceeded the annual eGFR decline in all participants. Furthermore, the larger the eGFR fluctuation, the more difficult it became to detect eGFR decline using a short-term eGFR analysis. Obesity, a high eGFR at baseline, and faster eGFR decline were associated with larger eGFR fluctuations. To circumvent the issue of eGFR fluctuation in the assessment of the rate of eGFR decline, we developed a system that generates a long-term eGFR plot using all eGFR values for a participant, which enabled the detection of occult CKD, facilitating early therapeutic intervention., Conclusion:The construction of long-term eGFR plots is useful for identifying patients with progressive eGFR decline, as it minimizes the effect of eGFR fluctuation.

Several reports have suggested that genetic susceptibility contributes to the development and progression of diabetic retinopathy. We aimed to identify genetic loci that confer susceptibility to diabetic retinopathy in Japanese patients with type 2 diabetes. We analysed 5 790 508 single nucleotide polymorphisms (SNPs) in 8880 Japanese patients with type 2 diabetes, 4839 retinopathy cases and 4041 controls, as well as 2217 independent Japanese patients with type 2 diabetes, 693 retinopathy cases and 1524 controls. The results of these two genome-wide association studies (GWAS) were combined with an inverse variance meta-analysis (Stage-1), followed by de novo genotyping for the candidate SNP loci (P

Aims:Identifying the mechanisms that underlie progression from endothelial damage to podocyte damage, which leads to massive proteinuria, is an urgent issue that must be clarified to improve renal outcome in diabetic kidney disease (DKD). We aimed to examine the role of dynamin-related protein 1 (Drp1)-mediated regulation of mitochondrial fission in podocytes in the pathogenesis of massive proteinuria in DKD., Methods:Diabetes- or albuminuria-associated changes in mitochondrial morphology in podocytes were examined by electron microscopy. The effects of albumin and other diabetes-related stimuli, including high glucose (HG), on mitochondrial morphology were examined in cultured podocytes. The role of Drp1 in podocyte damage was examined using diabetic podocyte-specific Drp1-deficient mice treated with neuraminidase, which removes endothelial glycocalyx., Results:Neuraminidase-induced removal of glomerular endothelial glycocalyx in nondiabetic mice led to microalbuminuria without podocyte damage, accompanied by reduced Drp1 expression and mitochondrial elongation in podocytes. In contrast, streptozotocin-induced diabetes significantly exacerbated neuraminidase-induced podocyte damage and albuminuria, and was accompanied by increased Drp1 expression and enhanced mitochondrial fission in podocytes. Cell culture experiments showed that albumin stimulation decreased Drp1 expression and elongated mitochondria, although HG inhibited albumin-associated changes in mitochondrial dynamics, resulting in apoptosis. Podocyte-specific Drp1-deficiency in mice prevented diabetes-related exacerbation of podocyte damage and neuraminidase-induced development of albuminuria. Endothelial dysfunction-induced albumin exposure is cytotoxic to podocytes. Inhibition of mitochondrial fission in podocytes is a cytoprotective mechanism against albumin stimulation, which is impaired under diabetic condition. Inhibition of mitochondrial fission in podocytes may represent a new therapeutic strategy for massive proteinuria in DKD.

Recent major clinical trials of the use of sodium–glucose cotransporter 2 (SGLT2) inhibitors in patients with type 2 diabetes have shown that they reduce three‐point major adverse cardiovascular events, cardiovascular death, hospitalization for heart failure (HF) and a composite renal outcome. These beneficial effects of SGLT2 inhibitors are also evident in type 2 diabetes patients with a previous history of atherosclerotic cardiovascular disease or advanced renal disease. HF is a major determinant of the prognosis of diabetes patients. Although HF with low ejection fraction can be effectively treated with antihypertensive drugs, these treatments do not reduce mortality in HF patients with preserved ejection fraction (HFpEF). HFpEF is clinically characterized by left ventricular diastolic dysfunction, perivascular fibrosis and stiffness of cardiomyocytes, defined as “cardiomyopathy”. Therefore, HFpEF is considered to be an entirely separate entity to HF with low ejection fraction. Recent studies have suggested that HFpEF might be treatable using SGLT2 inhibitors, which ameliorate visceral adiposity, insulin resistance, hyperglycemia, hyperlipidemia, volume overload, hypertension and cardiac inflammation. In the final part of the present review, we discuss the biochemical and molecular mechanisms of the effects of SGLT2 inhibitors in type 2 diabetes patients with HFpEF. These involve amelioration of the low nitric oxide production and oxidative stress, a reduction in cardiac inflammatory cytokine signaling, inhibition of Ca2+ overload, and an improvement in cardiac energy metabolism as a result of ketone body production. Investigations of the beneficial effects of SGLT2 inhibitors on cardiorenal outcomes, including hospitalization for HF, are now being carried out in preclinical and clinical studies., Heart failure is a major determinant of life prognosis in diabetes patients. Two potential mechanisms for the progression of heart failure in diabetes are reviewed – the development of heart failure with preserved ejection fraction and heart failure with low ejection fraction. Sodium–glucose cotransporter 2 inhibitors can protect progression of heart failure with preserved ejection fraction in diabetes patients by improving multiple metabolic and hemodynamic derangements, as well as by improving endothelial dysfunction, oxidative stress, pro‐inflammatory cytokine signaling, Ca++ overloading and metabolic crisis in cardiomyocytes in diabetes.

A 43-year-old male patient on maintenance hemodialysis had an enhanced computed tomography scan examination with iohexol for the first time 10 min before regular hemodialysis therapy. At the start of hemodialysis, no symptoms were observed, and the platelet count was 148,000/μl. Approximately 1 h after starting hemodialysis, dyspnea and chest discomfort appeared. Since oxygen saturation of the peripheral artery decreased to 87%, oxygen administration was immediately started while continuing hemodialysis therapy. Furthermore, gingival hemorrhage was observed, and the platelet count decreased to 5000/μl. We were carefully monitoring his conditions while continuing hemodialysis and oxygen administration, but no further deterioration was observed. Thereafter, these symptoms and severe thrombocytopenia gradually improved without additional treatment. At the end of hemodialysis, these symptoms completely disappeared. As well, the platelet count recovered to 35,000/μl at the end of hemodialysis and increased to 92,000/μl the next morning. From the clinical course, we diagnosed with contrast medium-induced thrombocytopenia. Acute thrombocytopenia is a rare complication induced by the contrast medium. Until now, 16 cases on contrast medium-induced thrombocytopenia have been reported. Our case spontaneously recovered from severe thrombocytopenia relatively earlier than previous reports. Our patient started hemodialysis therapy 10 min after an enhanced computed tomography examination. Early removal of contrast medium by hemodialysis might be associated with early improvement. We should acknowledge that contrast media have potential to induce severe thrombocytopenia, even in patients on maintenance hemodialysis.

To examine the cell-protective role of podocyte autophagy against glomerular endothelial dysfunction in diabetes, we analyzed the renal phenotype of tamoxifen (TM)-inducible podocyte-specific Atg5-deficient (iPodo-Atg5-/-) mice with experimental endothelial dysfunction. In both control and iPodo-Atg5-/- mice, high fat diet (HFD) feeding induced glomerular endothelial damage characterized by decreased urinary nitric oxide (NO) excretion, collapsed endothelial fenestrae, and reduced endothelial glycocalyx. HFD-fed control mice showed slight albuminuria and nearly normal podocyte morphology. In contrast, HFD-fed iPodo-Atg5-/- mice developed massive albuminuria accompanied by severe podocyte injury that was observed predominantly in podocytes adjacent to damaged endothelial cells by scanning electron microscopy. Although podocyte-specific autophagy deficiency did not affect endothelial NO synthase deficiency-associated albuminuria, it markedly exacerbated albuminuria and severe podocyte morphological damage when the damage was induced by intravenous neuraminidase injection to remove glycocalyx from the endothelial surface. Furthermore, endoplasmic reticulum stress was accelerated in podocytes of iPodo-Atg5-/- mice stimulated with neuraminidase, and treatment with molecular chaperone tauroursodeoxycholic acid improved neuraminidase-induced severe albuminuria and podocyte injury. In conclusion, podocyte autophagy plays a renoprotective role against diabetes-related structural endothelial damage, providing an additional insight into the pathogenesis of massive proteinuria in diabetic nephropathy.

OBJECTIVE Nonalbuminuric diabetic kidney disease (DKD) has become the prevailing phenotype in patients with type 2 diabetes. However, it remains unclear whether its prognosis is poorer than that of other DKD phenotypes. RESEARCH DESIGN AND METHODS A total of 2,953 Japanese patients with type 2 diabetes and estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2, enrolled in an observational cohort study in 2004, were followed until 2015. On the basis of albuminuria (>30 mg/g creatinine) and reduced eGFR ( RESULTS During the mean follow-up of 9.7 years, 113 patients died and 263 developed CVD. In nonalbuminuric DKD, the risks of death or CVD were not higher than those in no-DKD (adjusted hazard ratio 1.02 [95% CI 0.66, 1.60]) and the annual decline in eGFR was slower than in other DKD phenotypes. The risks of death or CVD in nonalbuminuric DKD without prior CVD were similar to those in no-DKD without prior CVD, whereas the risks in nonalbuminuric DKD with prior CVD as well as other DKD phenotypes were higher. CONCLUSIONS Nonalbuminuric DKD did not have a higher risk of mortality, CVD events, or renal function decline than the other DKD phenotypes. In nonalbuminuric DKD, the presence of macrovascular complications may be a main determinant of prognosis rather than the renal phenotype.

IntroductionWe investigated trends in the proportion of diabetes treatment and glycemic control, which may be altered by recent advances in insulin and non-insulin drugs, in Japanese patients with type 2 diabetes.Research design and methodsA serial cross-sectional study was performed using a multicenter large-population database from the Japan Diabetes Clinical Data Management study group. Patients with type 2 diabetes who attended clinics belonging to the study group between 2002 and 2018 were included to examine trends in glycated hemoglobin A1c (HbA1c) by treatment group using multivariable non-linear regression model.ResultsThe proportion of patients with insulin only decreased from 15.0% to 3.6%, patients with insulin+non-insulin drugs increased from 8.1% to 15.1%, patients with non-insulin drugs increased from 50.8% to 67.0%, and those with no drugs decreased from 26.1% to 14.4% from 2002 to 2018, respectively. The HbA1c levels of each group, except for no drugs, continued to decrease until 2014 (unadjusted mean HbA1c (%) from 2002 to 2014: from 7.89 to 7.45 for insulin only, from 8.09 to 7.63 for insulin+non-insulin, and from 7.51 to 6.98 for non-insulin) and remained unchanged thereafter. Among insulin-treated patients, use of human insulin decreased, use of long-acting analog insulin increased, and concomitant use of non-insulin drugs increased (from 35.1% in 2002 to 80.9% in 2018), which included increased use of dipeptidyl peptidase 4 inhibitors, sodium-glucose cotransporter 2 inhibitors, and glucagon-like peptide 1 receptor agonists, and the persistently high use of metformin.ConclusionsDuring the past two decades, combined use of insulin and non-insulin drugs increased and glycemic control improved and leveled off after 2014 in Japanese patients with type 2 diabetes. Further studies of the trend in association with age and factors related to metabolic syndrome are necessary to investigate strategies aiming at personalized medicine in diabetes care.

AIMS The roles of urinary albumin, eGFRcystatin (eGFRcys), and eGFRcreatinine (eGFRcre) in the progression of coronary artery calcification (CAC) remain unclear. Therefore, the present study investigated the relationship between kidney function and CAC progression. METHODS A total of 760 Japanese men aged 40-79 years were enrolled in this population-based study. Kidney function was measured using eGFRcre, eGFRcys, and the urine albumin-to-creatinine ratio. CAC scores were calculated using the Agatston method. CAC progression was defined as an annual increase of ＞10 Agatston units (AU) among men with 0＜CAC＜100 AU at baseline, that of ＞10% among those with CAC ≥ 100 AU, and any progression for those with CAC=0 at baseline. The relative risk (RR) of CAC progression based on kidney function was assessed using a robust Poisson regression model. RESULTS The mean follow-up period was 4.9 years. CAC progression was detected in 45.8% of participants. Positive associations between CAC progression and albuminuria (＞30mg/g) (RR: 1.29; 1.09 to 1.53; p=0.004) and low eGFRcys (＜60ml/min/1.73m2) (RR: 1.27; 1.05 to 1.53; p=0.012) remained significant after adjustments for age, the follow-up time, and computerized tomography type. Following further adjustments for hypertension, diabetes mellitus, dyslipidemia, C-reactive protein, and lifestyle factors, CAC progression was associated with albuminuria (RR: 1.20; 1.01 to 1.43; p=0.04) and low eGFRcys (RR: 1.19; 0.99 to 1.43; p=0.066), but not with eGFRcre. CONCLUSION CAC progression was associated with albuminuria; however, its relationship with eGFRcys was weakened by adjustments for risk factors.

IntroductionChanges in albuminuria or estimated glomerular filtration rate (eGFR) can be used as a surrogate endpoint of end-stage kidney disease (ESKD) in people with type 2 diabetes. We investigated whether the combined changes in albuminuria and eGFR are more strongly associated with future risk of ESKD.Research design and methodsUsing data from a multicenter observational cohort study of people with type 2 diabetes, we evaluated the association of percentage change in urine albumin to creatinine ratio (UACR) and/or annual change in eGFR over 2 years with subsequent ESKD risk.ResultsAmong 1417 patients with repeated albuminuria and eGFR over 2 years, 129 (9.1%) developed ESKD. Patients with >30% UACR decline had lower ESKD risk (HR 0.47; 95% CI 0.29 to 0.77), whereas those with >30% UACR increase had higher ESKD risk (HR 2.31; 95% CI 1.52 to 3.51), compared with those with minor UACR change. Patients with greater eGFR decline had an increased ESKD risk than those with minor eGFR change (a decline of 2/year): HR 4.19 (95% CI 1.87 to 9.38) and 2.89 (95% CI 1.32 to 6.33) for those with a decline of >5 and 2.5–5 mL/min/1.73 m2/year, respectively. When the combined changes in UACR and eGFR were used, the highest ESKD risk (HR 5.60; 95% CI 2.08 to 15.09) was observed among patients with >30% UACR increase and an eGFR decline of >5 mL/min/1.73 m2/year compared with those with a minor change in UACR and eGFR.ConclusionsCombined changes in albuminuria and eGFR over 2 years were strongly associated with future risk of kidney failure in patients with type 2 diabetes.

Aims/Introduction Diabetic kidney disease is characterized by increased albuminuria and/or a reduced glomerular filtration rate (GFR). We analyzed secular changes in the prevalence of albuminuria and reduced estimated GFR (eGFR) in Japanese patients with type 2 diabetes, and identified factors associated with these changes. Materials and Methods Using 1996, 2001, 2006 and 2014 cohort data from the Japanese serial cross‐sectional studies conducted at Shiga University of Medical Science, secular changes in the prevalence of diabetic kidney disease (albuminuria and/or reduced eGFR), patient characteristics and their associations were analyzed. Results The prevalence of microalbuminuria and macroalbuminuria decreased over time, whereas the prevalence of moderately reduced eGFR (30–60 mL/min/1.73 m2) and severely reduced eGFR (

We carried out impact experiments using cylindrical gypsum targets with various radii and investigated the crater on the top (flat) surface. At a ratio of projectile and target radii ∼1/20, the crater size abruptly increases; the spallation extends to the side surface of the targets. The results are closely similar to the previous ones on the curved surfaces. A shock wave propagation model, introduced by Suzuki et al. (2018, Icarus 301, 1–8), can represent such results as the steep increase of the size of the spallation zone in both cases of spherical and cylindrical targets. Using this model, the maximum fragment size is evaluated and agrees well with the experimental results. We found that the enlargement of the spallation zone is crucial to the transition from cratering to catastrophic disruption. We also carried out numerical calculations with iSALE code capable of simulating impact processes in solid materials. The maximum pressure distribution shows that the most parts of the spallation zone are not metamorphosed by shock waves. Also, the crater depth is represented by iSALE without damage models, while the “spallation” seems not to be well reproduced by iSALE even with the damage models.

Diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus is a leading cause of end-stage renal disease worldwide. An increase in the severity of albuminuria and a decrease in the glomerular filtration rate, by which the DKD stages are categorized, are associated with higher risks of not only end-stage renal disease but also all-cause mortality and cardiovascular mortality. Thus, an optimal management strategy and adequate assessment of therapeutic success are of great clinical and societal relevance to improve the prognosis in patients with type 2 diabetes mellitus and DKD. At present, comprehensive risk management for glycemia, blood pressure, lipid profile, and lifestyle habits is emphasized with respect to cardio-renal protection, rather than one single risk management approach. However, the pharmacological therapy aiming at strict control of these risk factors may be associated with an increased risk of adverse effects, particularly in older adults with diabetes. Accordingly, in the clinical practice of diabetes care, we need to individualize the treatment goals for each risk factor according to the health and social status of each patient with type 2 diabetes mellitus and DKD.

Aim/Introduction Diabetes and obesity are important health and economic concerns. We investigated the influence of obesity on diabetes control, the annual medical expenditures, and medications in Japanese patients with type 2 diabetes who were relatively lean in comparison to those in Western countries. Materials and Methods A total of 402 Japanese patients with type 2 diabetes were enrolled and their annual medical expenditures investigated. Obesity was defined as body mass index over 25 kg/m2, according to the obesity classifications from the Japan Society for the Study of Obesity. Results A total of 165 patients (41.0%) were classified as obese. The obese group was younger, had poor glycemic control, and higher frequency of hypertension than the non-obese group. The median total annual medical expenditures for all participants was 269,333 Japanese yen (interquartile: 169,664 to 437,437 Japanese yen), which was equivalent to approximately 2,450 US dollars. The annual medical expenditure was significantly higher in patients with obesity than in non-obese patients (P

Aims/Introduction To investigate the current status of achieved blood pressure levels in association with the number of antihypertensive drug classes as of 2013, and to explore the clinical correlates with achievement of target blood pressure in a large-scale cohort of Japanese individuals with type 2 diabetes. Materials and Methods A nationwide survey was carried out including 12,811 individuals with type 2 diabetes. Participants were divided by achieved blood pressure

Background O-linked β- N -acetylglucosamine modification O-GlcNAcylation) is a post-translational modification of intracellular proteins, serving as a nutrient sensor. Growing evidence has demonstrated its physiological and pathological importance in various mammalian tissues. This study examined the physiological role of O-GlcNAcylation in podocyte function and development. Methods O-GlcNAc transferase (Ogt) is a critical enzyme for O-GlcNAcylation and resides on the X chromosome. To abrogate O-GlcNAcylation in podocytes, we generated congenital and tamoxifen (TM)-inducible podocyte-specific Ogt knockout mice (Podo-Ogt y/- and TM-Podo-Ogt y/- , respectively) and analyzed their renal phenotypes. Results Podo-Ogt y/- mice showed normal podocyte morphology at birth. However, they developed albuminuria at 8 weeks of age, increasing progressively until age 32 weeks. Glomerular sclerosis, proteinuria-related tubulointerstitial lesions and markedly altered podocyte foot processes, with decreased podocin expression, were observed histologically in 32-week-old Podo-Ogt y/- mice. Next, we induced adult-onset deletion of the Ogt gene in podocytes by TM injection in 8-week-old TM-Podo-Ogt y/- mice. In contrast to Podo-Ogt y/- mice, the induced TM-Podo-Ogt y/- mice did not develop albuminuria or podocyte damage, suggesting a need for O-GlcNAcylation to form mature foot processes after birth. To test this possibility, 3-week-old Podo-Ogt y/- mice were treated with Bis-T-23, which stimulates actin-dependent dynamin oligomerization, actin polymerization and subsequent foot process elongation in podocytes. Albuminuria and podocyte damage in 16-week-old Podo-Ogt y/- mice were prevented by Bis-T-23 treatment. Conclusions O-GlcNAcylation is necessary for maturation of podocyte foot processes, particularly after birth. Our study provided new insights into podocyte biology and O-GlcNAcylation.

Hypoxia causes proximal tubular cell damage in diabetes, even though proximal tubular cells have an adaptive system to combat hypoxia involving induction of hypoxia factor-1 (HIF-1) and inhibition of mechanistic target of rapamycin complex 1 (mTORC1). Here, we examined the interference effect of altered glucose and lipid metabolism on the hypoxia responses in proximal tubular cells. In culture, hypoxia alone induced HIF-1 and inhibited mTORC1, preventing death in proximal tubular cells. However, hypoxia with high glucose and palmitate increased mTORC1 activity and promoted apoptosis in proximal tubular cells, which was inhibited by pharmacological and genetic inactivation of mTORC1. Since inhibition of all mTORC1's physiological functions regulated by growth factors including insulin causes various adverse effects, we screened for a microRNA that can inhibit only pro-apoptotic effects of mTORC1 to discover a safe therapeutic target. This screen found microRNA-148b-3p was able to specifically inhibit mTORC1-dependent apoptosis in hypoxic proximal tubular cells exposed to high glucose and palmitate, without affecting insulin-dependent mTORC1 activation. Furthermore, tumor necrosis factor receptor (TNFR) 2 was the target of microRNA-148b-3p and its suppression inhibited apoptosis. Finally, enhanced apoptosis with TNFR2 overexpression was found in hypoxic and mTORC1-activated proximal tubular cells in diabetic rats. Thus, diabetes activated mTORC1 even in hypoxic proximal tubular cells, leading to apoptosis by reducing microRNA-148b-3p expression. Modulating this pathogenic pathway may be a novel therapy for proximal tubular cell damage in diabetes.

J Am Soc Nephrol. 2019 Jun;30(6):962-978., 令和元年度

To explore novel genetic loci for diabetic nephropathy, we performed genome-wide association studies (GWAS) for diabetic nephropathy in Japanese patients with type 2 diabetes. We analyzed the association of 5,768,242 single nucleotide polymorphisms (SNPs) in Japanese patients with type 2 diabetes, 2,380 nephropathy cases and 5,234 controls. We further performed GWAS for diabetic nephropathy using independent Japanese patients with type 2 diabetes, 429 cases and 358 controls and the results of these two GWAS were combined with an inverse variance meta-analysis (stage-1), followed by a de novo genotyping for the candidate SNP loci (p < 1.0 x 10^) in an independent case-control study (Stage-2; 1,213 cases and 1,298 controls). After integrating stage-1 and stage-2 data, we identified one SNP locus, significantly associated with diabetic nephropathy; rs56094641 in FTO, P = 7.74 x 10^. We further examined the association of rs56094641 with diabetic nephropathy in independent Japanese patients with type 2 diabetes (902 cases and 1,221 controls), and found that the association of this locus with diabetic nephropathy remained significant after integrating all association data (P = 7.62 x 10^). We have identified FTO locus as a novel locus for conferring susceptibility to diabetic nephropathy in Japanese patients with type 2 diabetes., 論文

Diabetes mellitus causes systemic disorders. We previously demonstrated that diabetic condition forced bone marrow-derived cells (BMDCs) to express TNF-α, leading to the development of diabetic neuropathy in mice. Here, we hypothesized that these abnormal BMDCs are also involved in diabetic nephropathy. To test our hypothesis, mice were irradiated to receive total bone marrow (BM) from the transgenic mice expressing green fluorescent protein before diabetes was induced by streptozotocin. Confocal microscopy showed that the diabetic glomerulus had more BMDCs compared with the nondiabetic glomerulus. Most of these cells exhibited endothelial phenotypes, being negative for several markers, including podocin (a maker of podocyte), α8 integrin (mesangial cell), CD68, and F4/80 (macrophage). Next, the total BM of diabetic mice was transplanted into nondiabetic mice to examine if diabetic BM per se could cause glomerular injury. The recipient mice exhibiting normal glycemia developed albuminuria and mesangial expansion with an increase in capillary area. The number of BMDCs increased in the glomerulus of the recipient mice. These cells were found to exhibit the endothelial phenotype and to express TNF-α. These data suggest that diabetic BMDCs per se could initiate glomerular disease. Finally, eNOS knockout mice were used to examine if residential endothelial injury could attract BMDCs into the glomerulus. However, endothelial dysfunction due to eNOS deficiency failed to attract BMDCs into the glomerulus. In summary, BMDCs may be involved in the development of diabetic nephropathy.-Nobuta, H., Katagi, M., Kume, S., Terashima, T., Araki, S., Maegawa, H., Kojima, H., Nakagawa, T. A role for bone marrow-derived cells in diabetic nephropathy.

The aim of this study was to evaluate the safety, effectiveness, and health-related QOL impact of early rehabilitation in patients with nephrotic syndrome. Subjects consisted of 23 patients with nephrotic syndrome who had previously received steroid treatment. Patients worked performed quadriceps resistance training and aerobic training 5 days per week for 5 weeks. Urinary protein, albumin (Alb), creatinine (Cre), and blood urea nitrogen (BUN) were monitored once every week over a 5-week period based on medical records. The 36-item short form health survey (SF-36) score was used to evaluate health-related QOL. There was no significant difference in quadriceps force and no significant effect of age as shown by ANCOVA. Anaerobic threshold (AT) and peak oxygen consumption (peak VO2) both increased significantly. AT was affected by the degree of change in body weight according to ANCOVA. Cre and BUN were not significantly altered. Urinary protein showed a significant decrease and Alb was significantly increased. Only physical function (PF) in the SF-36 showed a significant improvement following the intervention. Our data indicate that early rehabilitation involving quadriceps resistance training and aerobic training for nephrotic syndrome is safe and effective.

Dipeptidyl peptidase (DPP)-4 inhibitors, a new class of antidiabetic agent, have recently been suggested to exert pleiotropic effects beyond glucose lowering. Renal prognosis in patients with diabetic nephropathy depends on the severity of tubulointerstitial injury induced by massive proteinuria. We thus examined the renoprotective effect of DPP-4 inhibitors on inflammation in cultured mouse proximal tubular cells stimulated with free fatty acid (FFA)-bound albumin. Linagliptin and higher concentrations of sitagliptin, vildagliptin, and alogliptin all inhibited FFA-bound albumin-induced increases in mRNA expression of MCP-1 in cultured mouse proximal tubular cells. Furthermore, linagliptin significantly inhibited tubulointerstitial injury induced by peritoneal injection of FFA-bound albumin, such as inflammation, fibrosis, and apoptosis, in mice without altering systemic characteristics including body weight, fasting blood glucose, and food intake. These results indicate that DPP-4 inhibitors pleiotropically exert a direct renoprotective effect, and may serve as an additional therapeutic strategy to protect proximal tubular cells against proteinuria in patients with diabetic nephropathy.

Free fatty acid-bound albumin (FFA-albumin)-related oxidative stress is involved in the pathogenesis of proximal tubular cell (PTC) damage and subsequent renal dysfunction in patients with refractory proteinuria. Nicotinamide adenine dinucleotide (NAD) metabolism has recently been focused on as a novel therapeutic target for several modern diseases, including diabetes. This study was designed to identify a novel molecule in NAD metabolism to protect PTCs from lipotoxicity-related oxidative stress. Among 19 candidate enzymes involved in mammalian NAD metabolism, the mRNA expression level of nicotinamide n-methyltransferase (NNMT) was significantly increased in both the kidneys of FFA-albumin-overloaded mice and cultured PTCs stimulated with palmitate-albumin. Knockdown of NNMT exacerbated palmitate-albumin-induced cell death in cultured PTCs, whereas overexpression of NNMT inhibited it. Intracellular concentration of 1-Methylnicotinamide (1-MNA), a metabolite of NNMT, increased and decreased in cultured NNMT-overexpressing and -knockdown PTCs, respectively. Treatment with 1-MNA inhibited palmitate-albumin-induced mitochondrial reactive oxygen species generation and cell death in cultured PTCs. Furthermore, oral administration of 1-MNA ameliorated oxidative stress, apoptosis, necrosis, inflammation, and fibrosis in the kidneys of FFA-albumin-overloaded mice. In conclusion, NNMT-derived 1-MNA can reduce lipotoxicity-mediated oxidative stress and cell damage in PTCs. Supplementation of 1-MNA may have potential as a new therapy in patients with refractory proteinuria.

Summary SGLT2 inhibitors offer strong renoprotection in subjects with diabetic kidney disease (DKD). But the mechanism for such protection is not clear. Here, we report that in damaged proximal tubules of high-fat diet-fed ApoE-knockout mice, a model of non-proteinuric DKD, ATP production shifted from lipolysis to ketolysis dependent due to hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1). We further found that empagliflozin raised endogenous ketone body (KB) levels, and thus its use or treatment with 1,3-butanediol, a KB precursor, prevented decreases in renal ATP levels and organ damage in the mice. The renoprotective effect of empagliflozin was abolished by gene deletion of Hmgcs2, a rate-limiting enzyme of ketogenesis. Furthermore, KBs attenuated mTORC1-associated podocyte damage and proteinuria in diabetic db/db mice. Our findings show that SGLT2 inhibition-associated renoprotection is mediated by an elevation of KBs that in turn corrects mTORC1 hyperactivation that occurs in non-proteinuric and proteinuric DKD.