Safety and efficacy of long-term nicotinamide mononucleotide supplementation on metabolism, sleep, and nicotinamide adenine dinucleotide biosynthesis in healthy, middle-aged Japanese men.

Obesity and aging are major risk factors for several life-threatening diseases. Accumulating evidence from both rodents and humans suggests that the levels of nicotinamide adenine dinucleotide (NAD+), a regulator of many biological processes, declines in multiple organs and tissues with aging and obesity. Administration of an NAD+ intermediate, nicotinamide mononucleotide (NMN), replenishes intracellular NAD+ levels and mitigates aging- and obesity-associated derangements in animal models. In this human clinical study, we aimed to investigate the safety and effects of 8-week oral administration of NMN on biochemical, metabolic, ophthalmologic, and sleep quality parameters as well as on chronological alterations in NAD+ content in peripheral tissues. An 8-week, single-center, single-arm, open-label clinical trial was conducted. Eleven healthy, middle-aged Japanese men received two 125-mg NMN capsules once daily before breakfast. The 8-week NMN supplementation regimen was well-tolerated; NAD+ levels in peripheral blood mononuclear cells increased over the course of NMN administration. In participants with insulin oversecretion after oral glucose loading, NMN modestly attenuated postprandial hyperinsulinemia, a risk factor for coronary artery disease (n = 3). In conclusion, NMN overall safely and effectively boosted NAD+ biosynthesis in healthy, middle-aged Japanese men, showing its potential for alleviating postprandial hyperinsulinemia.

Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men.

Recent studies have revealed that decline in cellular nicotinamide adenine dinucleotide (NAD+) levels causes aging-related disorders and therapeutic approaches increasing cellular NAD+ prevent these disorders in animal models. The administration of nicotinamide mononucleotide (NMN) has been shown to mitigate aging-related dysfunctions. However, the safety of NMN in humans have remained unclear. We, therefore, conducted a clinical trial to investigate the safety of single NMN administration in 10 healthy men. A single-arm non-randomized intervention was conducted by single oral administration of 100, 250, and 500 mg NMN. Clinical findings and parameters, and the pharmacokinetics of NMN metabolites were investigated for 5 h after each intervention. Ophthalmic examination and sleep quality assessment were also conducted before and after the intervention. The single oral administrations of NMN did not cause any significant clinical symptoms or changes in heart rate, blood pressure, oxygen saturation, and body temperature. Laboratory analysis results did not show significant changes, except for increases in serum bilirubin levels and decreases in serum creatinine, chloride, and blood glucose levels within the normal ranges, independent of the dose of NMN. Results of ophthalmic examination and sleep quality score showed no differences before and after the intervention. Plasma concentrations of N-methyl-2-pyridone-5-carboxamide and N-methyl-4-pyridone-5-carboxamide were significantly increased dose-dependently by NMN administration. The single oral administration of NMN was safe and effectively metabolized in healthy men without causing any significant deleterious effects. Thus, the oral administration of NMN was found to be feasible, implicating a potential therapeutic strategy to mitigate aging-related disorders in humans.

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.

Feasibility of regression of hypertension using contemporary antihypertensive agents.

BACKGROUND: Recently, we reported that transient treatment of genetically hypertensive rats with high-dose angiotensin receptor blocker (ARB) causes regression of established hypertension. In this study, we investigated whether treatment with candesartan or nifedipine controlled-release (CR) resulted in a sustained regression of hypertension in humans. METHODS: Patients aged 30 to 59 years with untreated stage 1 essential hypertension and a family history of hypertension were treated with the antihypertensive agents candesartan (n = 124) or nifedipine CR (n = 120). After 1 year of treatment (phase 1), the medications were tapered and discontinued (phase 2). During phase 2, home and office blood pressures were monitored for another year to assess posttreatment reoccurrence of stage 1 hypertension. RESULTS: In phase 1, after 1 year of treatment a similarly substantial BP decrease was seen in the candesartan (-24.5/16.1 mm Hg) and nifedipine (-26.8/18.0 mm Hg) groups. In phase 2 there was a substantial reoccurrence of hypertension; at the study end, only 1 patient was able to continue without antihypertensive medication. However, a Kaplan-Meier analysis revealed a significant delay of reoccurrence of hyper tension (P = 0.0001) in the candesartan group. CONCLUSIONS: One year of treatment with candesartan or nifedipine CR was not associated with marked regression of hypertension in humans at the standard doses used in this trial. However, withdrawal of candesartan was associated with a slightly longer delay before restarting medications. Further studies with larger doses of candesartan given over a longer time are required to determine whether such a regimen may induce sustainable and clinically relevant reversal of hypertension and alteration in its natural history.

[Roles of PPARgamma in preventing the development of atherosclerosis in LDL receptor null mice].

Thiazolidinediones are synthetic ligands for peroxisome proliferator activated receptor gamma. They have been demonstrated to possess cardioprotective effects in humans and antiatherogenic properties in animal models. We observed that atherosclerosis in low-density lipoprotein receptor null mice progressed when mice were fed a high-fat diet. Pioglitazone treatment of atherogenic mice prevented this progression of atherosclerosis from its middle stages of disease. However, pioglitazone, in combination with the withdrawal of a high-fat diet, was unable to reverse established atherosclerosis. These findings describe, in part, a general paradox of how therapeutic agents are evaluated in common murine models of atherosclerosis and the lack of therapeutic benefit of agents given to mice with established atherosclerotic lesions, and further, may have implications for human therapy.

Prevention and regression of hypertension: role of renal microvascular protection.

Hypertension is a disease which affects over 26.4% of the world adult population, therefore novel approaches to the prevention and treatment of this disease need to be examined. Previous studies from our and other laboratories have shown that treatment of spontaneously hypertensive rats (SHR) and Dahl salt-sensitive rats with a renin-angiotensin system (RAS) inhibitor during the 'critical period' in hypertension development results in prevention of the later development of hypertension. In humans, Julius et al. reported similar findings in the landmark TROPHY study. Recently, we reported that 'pulse' treatment of SHR with high-dose angiotensin receptor blocker (ARB) is effective in causing sustained reduction of already established hypertension, even when the treatment was started after the 'critical period'. These results suggest the possibility that 'regression' of established hypertension may become feasible, and we have started a prospective, multicenter clinical study (STAR CAST study) to examine this possibility. In our animal studies, we found that treatment of rats during the 'critical period' with an ARB inhibits the development of renal arteriolar hypertrophy. Moreover, a high-dose angiotensin blocker caused a remarkable reversal of renal arteriolar hypertrophy in SHR, which was associated with changes in microvascular MMP expression. These results suggest that changes in the renal microvasculature may have an important role in the mechanisms of hypertension prevention and regression by ARB.

Atherosclerosis in LDLR-knockout mice is inhibited, but not reversed, by the PPARgamma ligand pioglitazone.

Thiazolidinediones, a class of drugs for the treatment of type-2 diabetes, are synthetic ligands for peroxisome proliferator-activated receptor-gamma. They have been demonstrated to possess cardioprotective effects in humans and anti-atherogenic properties in animal models. However, the question remains whether a peroxisome proliferator-activated receptor-gamma ligand can reverse the development of atherosclerosis. In this study, we tested the effects of pioglitazone on the development of established atherosclerosis in low-density lipoprotein receptor-null mice. We observed that atherosclerosis in low-density lipoprotein receptor-null mice progressed when mice were fed a high-fat diet. Pioglitazone treatment of atherogenic mice prevented this progression of atherosclerosis from its middle stages of disease, but was not able to reverse it. Withdrawal of the high-fat diet from mice with advanced atherosclerosis did not result in a reduction in lesion sizes. Pioglitazone treatment also had no effect on advanced atherosclerosis. Levels of high density lipoprotein cholesterol correlated inversely with lesion development when pioglitazone was given during lesion progression. However, pioglitazone had no effect on circulating high density lipoprotein levels in mice in which treatment was initiated following 14 weeks on the high-fat diet. These findings have implications for the analysis of therapeutic agents in murine models of atherosclerosis and the use of pioglitazone in patients with established atherosclerosis.

The short treatment with the angiotensin receptor blocker candesartan surveyed by telemedicine (STAR CAST) study: rationale and study design.

Previous studies have shown that transient treatment of animal models of hypertension with an angiotensin receptor blocker (ARB) causes a sustained decrease in blood pressure values that persists even after the drug treatment is discontinued (J Am Soc Nephrol 12: 659-666, 2001; Nephron 91: 710-718, 2002; Hypertens Res 30: 63-75, 2007). These results have been shown to be clinically relevant by the recent TROPHY study (N Engl J Med 354: 1685-1697, 2006). We have recently found that transient treatment with an ARB may also cause regression of established hypertension in hypertensive rats (J Am Soc Nephrol 18: 157A, 2007). The Short Treatment with the Angiotensin Receptor Blocker Candesartan Surveyed by Telemedicine (STAR CAST) study is a prospective, randomized, open, blinded end-point study in patients aged 30-59 with a positive family history of hypertension that will be conducted in several centers in Japan. The aim of the study is to evaluate the antihypertensive drug withdrawal success rate, the median duration of drug withdrawal, and the changes in home and office blood pressure values in patients with mild hypertension after tapering and withdrawal of antihypertensive treatment following treatment for 1 year with the ARB candesartan or the calcium channel blocker (CCB) nifedipine slow-release. A unique feature of this study is the use of a home blood pressure monitoring telemedicine system (i-TECHO) to allow frequent evaluation of the changes in blood pressure in the trial patients. This study will be the first clinical study to examine if regression from stage 1 (mild) hypertension to prehypertension (high-normal blood pressure) is possible using an ARB or CCB.

Glucocorticoid regulation of proteoglycan synthesis in mesangial cells.

BACKGROUND: Proteoglycans are integral components of the mesangial matrix and glomerular permeability barrier. Recent studies have shown that changes in glomerular proteoglycan expression may play a major role in the pathogenesis of renal disease. Steroid hormones are used as first-choice therapy for the treatment of glomerular diseases, however, the effects of glucocorticoids on expression of glomerular proteoglycans are unknown. METHODS: This study examined the effects of in vitro and in vivo administration of dexamethasone on proteoglycan synthesis and gene expression of proteoglycan core proteins using rat (RMC) and human (HMC) mesangial cells. RESULTS: Treatment of cultured RMC with dexamethasone resulted in a dose- and time-dependent decrease (P < 0.05) in both cell-associated and secreted proteoglycan synthesis to approximately 50% of control levels. This effect was inhibited by the glucocorticoid antagonist mifepristone, and mimicked by prednisolone or corticosterone treatment. Separation of proteoglycans by ion-exchange and gel permeation chromatography suggested that chondroitin sulfate/dermatan sulfate proteoglycans were down-regulated after steroid treatment. Northern blot analysis, RT-PCR, Western blot, and promoter activity assays revealed that dexamethasone caused a significant decrease in decorin mRNA (to 61 +/- 8% of controls), whereas biglycan expression and promoter activity were increased after steroid treatment. A similar trend was found in glomeruli isolated from rats treated in vivo with dexamethasone. CONCLUSIONS: These results demonstrate that treatment of mesangial cells with steroids results in a decrease in total proteoglycan synthesis, as well as subtype-specific changes in proteoglycan core protein gene expression by transcriptional control, furthering our understanding of the effects of steroid treatment on the renal glomeruli.

Prepubertal treatment with angiotensin receptor blocker causes partial attenuation of hypertension and renal damage in adult Dahl salt-sensitive rats.

Recently, we have shown that treatment of stroke-prone spontaneously hypertensive rats with angiotensin inhibitors for a limited time-window before puberty results in an attenuation of hypertensive nephrosclerosis in later life. The aim of this study was to examine the applicability of this therapeutic paradigm to a low-renin model. Dahl salt-sensitive (Dahl-S) rats were fed a high-salt diet from age 6 weeks. Some rats were treated with the angiotensin receptor blocker (ARB) candesartan cilexetil (2 mg/kg/d) from weaning to puberty (age 3-10 weeks), whereas other rats were treated continuously until overt renal damage was seen (age 3-16 weeks). Dahl-S rats on a high salt diet had increased blood pressure (207 +/- 3 vs. 125 +/- 2 mm Hg), proteinuria, and glomerular/vascular histological changes. The prepubertal treatment with ARB resulted in a continued suppression of blood pressure (153 +/- 2 mm Hg) at 16 weeks. Both proteinuria and renal histological changes were significantly (p < 0.05) attenuated, but not completely prevented by the treatment. No significant differences in plasma renin activity, renin mRNA, or AT1/AT2 mRNA were seen between groups. These results suggest that prepubertal treatment affords sustained renoprotection, even in an animal model with a suppressed renin-angiotensin system, and support the notion that appropriate prepubertal intervention may lead to a partial attenuation in the susceptibility to inherited renal diseases.

Regulation of vascular proteoglycan synthesis by angiotensin II type 1 and type 2 receptors.

Recent studies have shown that proteoglycans play an important role in the development of vascular disease and renal failure. In this study, the effects of angiotensin II (AngII) type 1 (AT1) and type 2 (AT2) receptor stimulation on glycosaminoglycan and proteoglycan core protein synthesis in vascular smooth muscle cells (VSMC) were examined. Treatment of AT1 receptor-expressing VSMC with AngII resulted in a dose-dependent and time-dependent increase (2- to 4-fold) in (3)H-glucosamine/(35)S-sulfate incorporation, which was abolished by pretreatment with the AT1 receptor antagonist, losartan. The effects of AngII were inhibited by the epidermal growth factor receptor inhibitor, AG1478, and the mitagen-activated protein kinase kinase inhibitor, PD98059, but not the protein kinase C inhibitors, chelerythrine and staurosporine. AngII treatment also resulted in significant increases in the mRNA of the core proteins, versican, biglycan, and perlecan. The effects of AT2 receptor stimulation were examined by retroviral transfection of VSMC with the AT2 receptor. Stimulation of the AT2 receptor in these VSMC-AT2 cells resulted in a significant (1.3-fold) increase in proteoglycan synthesis, which was abolished by the AT2 receptor antagonist, PD123319, and attenuated by pretreatment with pertussis toxin. These results implicate both AT1 and AT2 receptors in the regulation of proteoglycan synthesis and suggest the involvement of epidermal growth factor receptor-dependent tyrosine kinase pathways and G alpha i/o-mediated mechanisms in the effects of the two receptors.

Temporary treatment of prepubescent rats with angiotensin inhibitors suppresses the development of hypertensive nephrosclerosis.

Hypertensive nephrosclerosis is a leading cause of end-stage renal disease; therefore, strategies to prevent the development of renal disease require close study. Here it is demonstrated that transient treatment of prepubescent rats with angiotensin inhibitors attenuated their susceptibility to the development of hypertensive nephrosclerosis after maturation. Stroke-prone spontaneously hypertensive Izumo strain rats were divided into four groups, treated with vehicle, the angiotensin-converting enzyme inhibitor (ACEI) delapril (40 mg/kg per d), the angiotensin receptor antagonist (AT1R-Ant) candesartan cilexetil (1 mg/kg per d), or the vasodilator hydralazine (25 mg/kg per d) from weaning to puberty (3 to 10 wk of age), and then monitored without treatment for 6 mo. BP in the ACEI- and AT1R-Ant-treated groups remained significantly decreased, compared with the untreated and hydralazine-treated groups. Moreover, marked proteinuria and nephrosclerosis developed in the untreated and hydralazine-treated groups at 30 wk but were suppressed in the ACEI- and AT1R-Ant-treated groups. Of interest, plasma renin activity, plasma angiotensin II concentrations, and renal renin mRNA levels were reduced by >50% in the ACEI- and AT1R-Ant-treated rats, suggesting that the treatments may have attenuated the development of nephrosclerosis by overcoming the susceptibility of stroke-prone spontaneously hypertensive rats to overactivation of the renin-angiotensin system.