Intermittent Fasting Sustainably Improves Glucose Tolerance in Normal Weight Male Mice Through Histone Hyperacetylation.

To explore the mechanism by which intermittent fasting (IF) exerts prolonged effects after discontinuation, we examined mice that had been subjected to 4 cycles of fasting for 72 hours and ad libitum feeding for 96 hours per week (72hIF), followed by 4 weeks of ad libitum feeding, focusing on expression of genes for lipid metabolism in the skeletal muscle and histone acetylation in the promoter region. The 72hIF regimen resulted in metabolic remodeling, characterized by enhanced lipid utilization and mitochondrial activation in the muscle. This long-term IF (72hIF) caused stronger metabolic effects than alternate day fasting (24hIF) wherein fasting and refeeding are repeated every 24 hours. Upregulation of lipid oxidation genes and an increase in oxygen utilization were sustained even at 4 weeks after discontinuation of 72hIF, associated with histone hyperacetylation of the promoter region of uncoupling protein 3 (Ucp3) and carnitine palmitoyl transferase 1b (Cpt1b) genes. An increase in leucine owing to fasting-induced muscle degradation was suggested to lead to the histone acetylation. These findings support the previously unappreciated notion that sustainable promotion of histone acetylation in lipid oxidation genes of the muscle and adipose tissues during and after IF may contribute to sustained metabolic effects of IF.

Safety and feasibility of radiofrequency ablation using bipolar electrodes for aldosterone-producing adenoma: a multicentric prospective clinical study.

Evaluation of feasibility and safety of percutaneous radiofrequency ablation using bipolar radiofrequency devices in a prospective multicenter cohort of patients with benign aldosterone-producing adenoma. A total of five institutions participated. CT-guided percutaneous RFA was performed for patients diagnosed as APA. The safety of the procedure was evaluated using the Common Terminology Criteria for Adverse Events. During the 84-day follow-up period, serial changes in plasma aldosterone concentration and plasma renin activity were measured. The percentage of patients with normalized hormonal activity after the procedure, was calculated with 95% confidence intervals. Forty patients were enrolled, and two patients were excluded for cerebral hemorrhage and no safe puncture root. In another patients, RFA was tried, but an intraprocedural intercostal arterial injury occurred. Consequently, RFA was completed in thirty-seven patients (20 men, 17 women; mean age, 50.4 ± 10.0 year). The tumor size was 14.8 ± 3.8 mm. The treatment success rate of the ablation was 94.6% (35/37), and a 2nd session was performed in 2.7% (1/37) patients. Grade 4 adverse events were observed in 4 out of 38 sessions (10.5%). The normalization of plasma aldosterone concentration or aldosterone-renin ratio was 86.5% (72.0-94.1: 95% confidence interval) on day 84. Percutaneous CT-guided RFA for APA using a bipolar radiofrequency system was safe and feasible with clinical success rate of 86.5% on day 84.

Predictors of renal function after adrenalectomy in patients with Cushing or subclinical Cushing syndrome.

PURPOSE: The postoperative course of renal function remains unclear in Cushing syndrome. We examined changes in renal function after adrenalectomy in patients with Cushing syndrome and attempted to identify predictors of renal impairment. METHODS: The study population comprised 76 patients who underwent adrenalectomy for Cushing and subclinical Cushing syndrome between 2001 and 2018. Renal function and other factors were evaluated pre-operation, at 1 postoperative month, and 1 postoperative year. We defined a ≥10% decrease in the estimated glomerular filtration rate at 1 postoperative year as renal impairment, and predictors associated with this reduction were investigated. The relationship between renal function and steroid replacement after surgery was also examined. RESULTS: Mean pre-operative estimated glomerular filtration rate was 82.2 ml/min/1.73 m2 . While mean estimated glomerular filtration rate was significantly lower at 1 postoperative month than the pre-operative value (71.7 ml/min/1.73 m2 [89.1%], p < 0.001), no significant differences were observed between 1 postoperative year and pre-operation (79.5 ml/min/1.73 m2 [97.6%], p = 0.108). Twenty-six patients (34.2%) developed renal impairment. A multivariate analysis identified a low pre-operative adrenocorticotropic hormone level as an independent predictor of renal impairment (odds ratio 6.30, p = 0.031). Among 43 patients with available records of steroid replacement history, 18 (41.9%) developed renal impairment. The ratio of patients with a reduced steroid replacement dose at 1 postoperative month was significantly lower among patients with renal impairment than those without (22.2% vs. 56.0%, p = 0.027). CONCLUSIONS: The pre-operative adrenocorticotropic hormone level was a predictor of renal function after adrenalectomy in patients with Cushing or subclinical Cushing syndrome.

Chromatin Immunoprecipitation and Circadian Rhythms.

Organisms exhibit daily changes of physiology and behavior to exert homeostatic adaptations to day-night cycles. The cyclic fluctuation also takes place at transcriptional levels, giving rise to rhythmic gene expression. Central to this oscillatory transcription is the core clock machinery which constitutes a circuit of transcriptional-translational feedback and achieves circadian functions accordingly. Chromatin immunoprecipitation provides understanding of such mechanisms that clock and non-clock transcription factors along with co-regulators and chromatin modifications dictate circadian epigenome through cyclic alterations of chromatin structures and molecular functions in a concerted fashion. Besides, innovation of high-throughput sequencing technology has broadened our horizon and renewed perspectives in circadian research. This article summarizes the methodology of a chromatin immunoprecipitation experiment in light of circadian rhythm research.

Intestinal Epithelial NAD+ Biosynthesis Regulates GLP-1 Production and Postprandial Glucose Metabolism in Mice.

Obesity is associated with perturbations in incretin production and whole-body glucose metabolism, but the precise underlying mechanism remains unclear. Here, we tested the hypothesis that nicotinamide phosphoribosyltransferase (NAMPT), which mediates the biosynthesis of nicotinamide adenine dinucleotide (NAD+), a key regulator of cellular energy metabolism, plays a critical role in obesity-associated intestinal pathophysiology and systemic metabolic complications. To this end, we generated a novel mouse model, namely intestinal epithelial cell-specific Nampt knockout (INKO) mice. INKO mice displayed diminished glucagon-like peptide-1 (GLP-1) production, at least partly contributing to reduced early-phase insulin secretion and postprandial hyperglycemia. Mechanistically, loss of NAMPT attenuated the Wnt signaling pathway, resulting in insufficient GLP-1 production. We also found that diet-induced obese mice had compromised intestinal NAMPT-mediated NAD+ biosynthesis and Wnt signaling pathway, associated with impaired GLP-1 production and whole-body glucose metabolism, resembling the INKO mice. Finally, administration of a key NAD+ intermediate, nicotinamide mononucleotide (NMN), restored intestinal NAD+ levels and obesity-associated metabolic derangements, manifested by a decrease in ileal Proglucagon expression and GLP-1 production as well as postprandial hyperglycemia in INKO and diet-induced obese mice. Collectively, our study provides mechanistic and therapeutic insights into intestinal NAD+ biology related to obesity-associated dysregulation of GLP-1 production and postprandial hyperglycemia.

Activation of the intestinal tissue renin-angiotensin system by transient sodium loading in salt-sensitive rats.

BACKGROUND: The renal tissue renin-angiotensin system is known to be activated by salt loading in salt-sensitive rats; however, the response in other organs remains unclear. METHOD: Spontaneously hypertensive rats were subjected to normal tap water or transient high-salt-concentration water from 6 to 14 weeks of age and were thereafter given normal tap water. From 18 to 20 weeks of age, rats given water with a high salt concentration were treated with an angiotensin II type 1 receptor blocker, valsartan. RESULTS: Sustained blood pressure elevation by transient salt loading coincided with a persistent decrease in the fecal sodium content and sustained excess of the circulating volume in spontaneously hypertensive rats. Administration of valsartan sustainably reduced the blood pressure and normalized the fecal sodium levels. Notably, transient salt loading persistently induced the intestinal tissue renin-angiotensin system and enhanced sodium transporter expression exclusively in the small intestine of salt-sensitive rats, suggesting the potential connection of intestinal sodium absorption to salt sensitivity. CONCLUSION: These results reveal the previously unappreciated contribution of the intestinal tissue renin-angiotensin system to sodium homeostasis and blood pressure regulation in the pathophysiology of salt-sensitive hypertension.

Remission of Angiographically Confirmed Minocycline-induced Renal Polyarteritis Nodosa: A Case Report and Literature Review.

A 23-year-old man presented with severe hypertension. Based on his history of minocycline treatment for over three years and clinical symptoms, such as myalgias and renovascular hypertension with multiple intrarenal aneurysms, he was diagnosed with minocycline-induced renal polyarteritis nodosa (PAN). After minocycline treatment cessation and management of the hypertension, his blood pressure, renin-aldosterone levels, and urinary protein levels gradually improved. Seven and a half years later, repeated angiography found that the aneurysms had resolved. This is the first report in English describing a case of minocycline-induced renal PAN that was reversed functionally and morphologically without steroids or immunosuppressive drugs.

DNA repair factor KAT5 prevents ischemic acute kidney injury through glomerular filtration regulation.

The "preconditioning effect" in AKI is a phenomenon in which an episode of ischemia-reperfusion results in tolerance to subsequent ischemia-reperfusion injury. However, its relationship between DNA damage repair has not been elucidated. Here, we show the role of KAT5 in the preconditioning effect. Preconditioning attenuated DNA damage in proximal tubular cells with elevated KAT5 expression. Ischemia-reperfusion (IR) injuries were exacerbated, and preconditioning effect vanished in proximal tubular-cell-specific KAT5 knockout mice. Investigation of tubuloglomerular feedback (TGF) by MALDI-IMS and urinary adenosine revealed that preconditioning caused attenuated TGF at least in part via KAT5. In addition, K-Cl cotransporter 3 (KCC3) expression decreased in damaged proximal tubular cells, which may be involved in accelerated TGF following IR. Furthermore, KAT5 induced KCC3 expression by maintaining chromatin accessibility and binding to the KCC3 promoter. These results suggest a novel mechanism of the preconditioning effect mediated by the promotion of DNA repair and attenuation of TGF through KAT5.

Home-based aerobic exercise and resistance training for severe chronic kidney disease: a randomized controlled trial.

BACKGROUND: The potential effects of aerobic and resistance training in patients with severe chronic kidney disease (CKD) are not fully elucidated. This study investigated the effects of a home-based exercise programme on physical functioning and health-related quality of life (HRQOL) in patients with Stage 4 CKD, equivalent to estimated glomerular filtration rate of 15-30 mL/min/1.73 m2 . METHODS: Forty-six patients with Stage 4 CKD (median age, 73 years; 33 men) were randomly assigned to exercise (n = 23) and control (n = 23) groups. Exercise group patients performed aerobic exercise at 40-60% peak heart rate thrice weekly and resistance training at 70% of one-repetition maximum twice weekly at home for 6 months. Control patients received no specific intervention. Primary outcomes were distance in incremental shuttle walking test and HRQOL assessed using the Kidney Disease Quality of Life-Short Form questionnaire. Secondary outcomes included kidney function assessed with combined urea and creatinine clearance, urinary biomarkers, and anthropometric and biochemical parameters associated with CKD. RESULTS: Improvement in incremental shuttle walking test was significantly greater in the exercise group compared with controls (39.4 ± 54.6 vs. -21.3 ± 46.1; P < 0.001). Among Kidney Disease Quality of Life domains, significant mean differences were observed between the exercise group and the control group in work status, quality of social interaction, and kidney disease component summary outcomes (12.76 ± 5.76, P = 0.03; 5.97 ± 2.59, P = 0.03; and 4.81 ± 1.71, P = 0.007, respectively). There were greater reductions in natural log (ln)-transformed urinary excretion of liver-type fatty acid-binding protein, ln serum C-reactive protein, and acylcarnitine to free carnitine ratio in the exercise group compared with controls, with significant between-group differences of -0.579 ± 0.217 (P = 0.008), -1.13 ± 0.35 (P = 0.003), and -0. 058 ± 0.024 (P = 0.01), respectively. CONCLUSIONS: Our 6 month home-based exercise programme improved aerobic capacity and HRQOL in patients with Stage 4 CKD, with possible beneficial effects on kidney function and CKD-related parameters.

Transient Dexamethasone Loading Induces Prolonged Hyperglycemia in Male Mice With Histone Acetylation in Dpp-4 Promoter.

Glucocorticoid causes hyperglycemia, which is common in patients with or without diabetes. Prolonged hyperglycemia can be experienced even after the discontinuation of glucocorticoid use. In the present study, we examined the time course of blood glucose level in hospital patients who received transient glucocorticoid treatment. In addition, the mechanism of prolonged hyperglycemia was investigated by using dexamethasone (Dexa)-treated mice and cultured cells. The blood glucose level in glucose tolerance tests, level of insulin and glucagon-like peptide 1 (GLP-1), and the activity of dipeptidyl peptidase 4 (DPP-4) were examined during and after Dexa loading in mice, with histone acetylation level of the promoter region. Mice showed prolonged hyperglycemia during and after transient Dexa loading accompanied by persistently lower blood GLP-1 level and higher activity of DPP-4. The expression level of Dpp-4 was increased in the mononuclear cells and the promoter region of Dpp-4 was hyperacetylated during and after the transient Dexa treatment. In vitro experiments also indicated development of histone hyperacetylation in the Dpp-4 promoter region during and after Dexa treatment. The upregulation of Dpp-4 in cultured cells was significantly inhibited by a histone acetyltransferase inhibitor. Moreover, the histone hyperacetylation induced by Dexa was reversible by treatment with a sirtuin histone deacetylase activator, nicotinamide mononucleotide. We identified persistent reduction in blood GLP-1 level with hyperglycemia during and after Dexa treatment in mice, associated with histone hyperacetylation of promoter region of Dpp-4. The results unveil a novel mechanism of glucocorticoid-induced hyperglycemia, and suggest therapeutic intervention through epigenetic modification of Dpp-4.

Mediastinal Cystic Parathyroid Adenoma Diagnosed by Somatostatin Receptor Scintigraphy.

A 71-year-old man complained of nausea and loss of appetite for eight months prior to admission. He was transported to a hospital with disorientation and diagnosed with primary hyperparathyroidism by laboratory examinations. However, ultrasonography, computed tomography, and technetium-99m labeled methoxyisobutyl isonitrile (99mTc-MIBI) with single-photon emission computed tomography did not yield definite results. In contrast, somatostatin receptor scintigraphy successfully identified the lesion responsible for the over-secretion of parathyroid hormone within the middle mediastinum. The tumor was successfully resected by surgery, and a histopathological analysis confirmed the parathyroid adenoma nature of the tumor.

Exercise Parameters Predict Technique Survival in Patients on Peritoneal Dialysis.

OBJECTIVE: The incremental shuttle walking test (ISWT) is an important marker of aerobic capacity in patients on peritoneal dialysis (PD). This study aimed to evaluate its predictive value for PD-related outcomes. METHODS: This single-center cohort study recruited outpatients on maintenance PD from our hospital between March 2017 and March 2018. Exercise capacity was assessed using measurement of ISWT and handgrip and quadriceps strength. Patients were divided into 2 groups according to the median of exercise capacity and prospectively followed up until cessation of PD, death, or the study end (October 2019). The primary end point of this study was technique survival rate, and secondary outcomes were rates of peritonitis-free survival and PD-related hospitalization-free survival. RESULTS: Among the 50 participants, age and PD vintage were [median (IQR)] 62.5 (58.3-70) and 3.5 (1.3-6.5) years, respectively. At the end of the study, 3 of the 28 participants (11%) in the long-ISWT group and 13 of the 22 participants (59%) in the short-ISWT group were transferred to hemodialysis. The short-ISWT group showed lower technique survival rate (p < 0.001), peritonitis-free survival rate (p = 0.01), and PD-related hospitalization-free survival rate (p < 0.01) than the long-ISWT group, whereas those survival rates did not differ when participants were divided by handgrip or quadriceps strength. Multivariate analysis revealed lower ISWT to be independently associated with technique failure (p = 0.002). CONCLUSION: The ISWT is an important predictor of technique survival for patients on PD. Monitoring and enhancing ISWT as a marker of aerobic capacity might improve PD-related outcomes.

Effect of long-term amiodarone treatment on thyroid function in euthyroid Japanese patients: a 12-month retrospective analysis.

Amiodarone is an effective antiarrhythmic drug. However, it is associated with changes in thyroid function in euthyroid patients due to its high iodine content and intrinsic drug effects. Studies have been conducted in iodine-deficient and iodine-sufficient countries; however, data from countries with excessive iodine intake are lacking. Thus, this study aimed to evaluate the effect of long-term amiodarone treatment on thyroid function in euthyroid Japanese patients. Japanese adults aged ≥18 years who were treated with amiodarone for at least 90 consecutive days were included in this retrospective chart review. Patients with abnormal thyroid function test results at baseline were excluded. Serial changes in thyroid function tests at baseline and at days 30, 90, 180, 270, and 360 were analyzed using a mixed-effects model for repeated measures. In total, 46 patients with a mean age of 63.7 years were evaluated. The mean TSH level significantly increased from 1.62 µIU/mL at baseline to 3.43, 2.75, 2.84, 2.78, and 2.65 µIU/mL at days 30, 90, 180, 270, and 360, respectively. The mean free T4 level significantly increased from 1.3 ng/dL at baseline to 1.4, 1.5, 1.5, 1.5, and 1.5 ng/dL at days 30, 90, 180, 270, and 360, respectively. The mean free T3 level significantly decreased from 2.8 pg/mL at baseline to 2.4, 2.3, 2.3, 2.4, and 2.4 pg/mL at days 30, 90, 180, 270, and 360, respectively. In conclusion, significant changes in thyroid function persisted not only in the acute phase but also in the chronic phase of long-term amiodarone treatment.

Effects of exercise on residual renal function in patients undergoing peritoneal dialysis: A post-hoc analysis of a randomized controlled trial.

We aimed to investigate the effects of exercise on renal outcomes in patients undergoing peritoneal dialysis (PD). In a post-hoc analysis of a randomized controlled trial of a 12-week home-based exercise program involving 47 patients undergoing PD, we excluded 18 patients with anuria and analyzed 13 and 16 patients in the usual care and exercise groups, respectively. The primary outcomes were weekly renal creatinine clearance (CCr) and urinary biomarkers: liver-type fatty acid-binding protein (L-FABP) and the microalbumin-to-creatinine ratio (ACR). Although the maintenance of weekly renal CCr in the exercise group was not significantly different compared with that in the usual care group (P = .09), urinary L-FABP levels (P = .02) and ACR (P = .04) were significantly decreased in the exercise group. To the best of our knowledge, this is the first study to demonstrate the beneficial effects of exercise on renal outcomes in patients undergoing PD.

Xanthine oxidase inhibitor ameliorates postischemic renal injury in mice by promoting resynthesis of adenine nucleotides.

Although oxidative stress plays central roles in postischemic renal injury, region-specific alterations in energy and redox metabolism caused by short-duration ischemia remain unknown. Imaging mass spectrometry enabled us to reveal spatial heterogeneity of energy and redox metabolites in the postischemic murine kidney. After 10-minute ischemia and 24-hour reperfusion (10mIR), in the cortex and outer stripes of the outer medulla, ATP substantially decreased, but not in the inner stripes of the outer medulla and inner medulla. 10mIR caused renal injury with elevation of fractional excretion of sodium, although histological damage by oxidative stress was limited. Ischemia-induced NADH elevation in the cortex indicated prolonged production of reactive oxygen species by xanthine oxidase (XOD). However, consumption of reduced glutathione after reperfusion suggested the amelioration of oxidative stress. An XOD inhibitor, febuxostat, which blocks the degradation pathway of adenine nucleotides, promoted ATP recovery and exerted renoprotective effects in the postischemic kidney. Because effects of febuxostat were canceled by silencing of the hypoxanthine phosphoribosyl transferase 1 gene in cultured tubular cells, mechanisms for the renoprotective effects appear to involve the purine salvage pathway, which uses hypoxanthine to resynthesize adenine nucleotides, including ATP. These findings suggest a novel therapeutic approach for acute ischemia/reperfusion renal injury with febuxostat through salvaging high-energy adenine nucleotides.

Acute Interstitial Nephritis With Karyomegalic Epithelial Cells After Nivolumab Treatment-Two Case Reports.

Clinical application of immune checkpoint inhibitors (CPIs) including nivolumab is expanding in the field of oncology treatment. Nivolumab is an anti-programmed death 1 protein (PD-1) antibody designed to augment an immunologic reaction against cancer cells. On the contrary, CPIs are known to cause a unique variety of side effects termed as immune-related adverse events, which can affect any organ including kidney. However, the characteristics of renal disorders by nivolumab treatment are poorly described. We describe two cases of acute kidney injury that were treated with nivolumab. Two patients, one with renal-cell carcinoma and the other with lung cancer, exhibited progressive renal dysfunction after the initiation of nivolumab treatment. By kidney biopsy, each case was diagnosed as acute interstitial nephritis (AIN). Of note, tubular epithelial cells enlarged with hyperchromatic nuclei were focally observed, and this finding was consistent with karyomegalic tubular epithelial cells. In immunostaining, most of the enlarged tubular epithelial cells were positive for Ki-67, which suggested regeneration of tubular epithelial cells. Clinically, in one case, renal function was partially recovered with the discontinuation of nivolumab, while in another case renal function was fully recovered with additional corticosteroid treatment. We presented nivolumab-induced AIN with karyomegalic changes of tubular epithelia. We propose that immunosuppressive therapy may be necessary for the full recovery from renal impairment.

Home-based Aerobic Exercise and Resistance Training in Peritoneal Dialysis Patients: A Randomized Controlled Trial.

Potential effects of aerobic and resistance training in peritoneal dialysis (PD) patients have been partially elucidated. We investigated effects of a home-based exercise program on physical functioning and health-related quality of life (HRQOL) in PD patients. Patients were randomly assigned to exercise (n = 24) and usual care (n = 23) groups. The exercise patients performed aerobic exercise thrice weekly and resistance training twice weekly at home for 12 weeks. The usual care patients received no specific intervention. The distance in incremental shuttle walking test significantly improved in the exercise group compared with the usual care group (P = 0.02). Among the HRQOL subscales assessed using the Kidney Disease Quality of Life-Short Form questionnaire, kidney disease component summary (P = 0.03), physical role functioning (P = 0.01), emotional role functioning (P < 0.01), and role/social component summary (P < 0.01) significantly improved in the exercise group. Moreover, serum albumin was significantly maintained in the exercise group (P = 0.03). There were no reported adverse events associated with the intervention. To our knowledge, this is the first randomized controlled trial to indicate the beneficial effects of a 12-week home-based exercise program exclusively in PD patients.

Exercise Capacity and Association with Quality of Life in Peritoneal Dialysis Patients.

BACKGROUND: Muscle wasting, common and progressive in uremic patients, is associated with a high probability for morbidity, lower health-related quality of life (HRQOL), and mortality. However, exercise tolerance in peritoneal dialysis (PD) patients has not been fully elucidated. The aim of this study was to evaluate exercise capacity, its determinants, and its association with HRQOL in PD patients. METHODS: Outpatients treated with PD at Keio University Hospital from December 2016 to March 2018 were included in this single-center cross-sectional observational study. Exercise capacity was assessed by incremental shuttle walking test (ISWT) and handgrip and quadriceps strength. In addition to evaluation of PD-related parameters, HRQOL was assessed by the Kidney Disease Quality of Life-Short Form questionnaire. RESULTS: Among the 50 recruited PD outpatients, age and PD vintage were 63.8 ± 9.6 and 3.8 ± 2.8 years, respectively. Physical examination revealed ISWT of 312.0 ± 138.2 m, handgrip strength of 27.5 ± 6.9 kg, and quadriceps strength of 23.3 ± 10.0 kg. Multivariate analysis showed that younger age and male sex were significantly associated with higher ISWT and handgrip and quadriceps strength. Skeletal mass index (SMI) remained a significant predictor of handgrip and quadriceps strength. Moreover, only ISWT was strongly correlated with higher HRQOL scores, including physical, mental, and kidney-specific domains, even after adjustment for age and sex. CONCLUSIONS: Exercise tolerance in PD patients was partially determined by age, sex, and SMI. Moreover, this is the first study to demonstrate the strong relationship between aerobic capacity and HRQOL in PD patients.