Excessive reactive oxygen species (ROS) induce apoptosis and are associated with various diseases and with aging. SIRT1 (sirtuin-1), an NAD+-dependent protein deacetylase, decreases ROS levels and ...participates in cell survival under oxidative stress conditions. SIRT1 modulates the transcription factors p53, a tumor suppressor and inducer of apoptosis, and the forkhead O (FOXO) family, both of which play roles for cell survival and cell death. In this study, we aimed to know which is working greatly among p53 and FOXOs transcription factors in SIRT1's cell protective functions under oxidative stress conditions. The antimycin A-induced increase in ROS levels and apoptosis was enhanced by SIRT1 inhibitors nicotinamide and splitomicin, whereas it was suppressed by a SIRT1 activator, resveratrol, and a SIRT1 cofactor, NAD+. SIRT1-siRNA abolished the effects of splitomicin and resveratrol. p53-knockdown experiment in C2C12 cells and experiment using p53-deficient HCT116 cells showed that splitomicin and resveratrol modulated apoptosis by p53-dependent and p53-independent pathways. In p53-independent cell protective pathway, we found that FOXO1, FOXO3a, and FOXO4 were involved in SOD2's upregulation by resveratrol. The knockdown of these three FOXOs by siRNAs completely abolished the SOD2 induction, ROS reduction, and anti-apoptotic function of resveratrol. Our results indicate that FOXO1, FOXO3a and FOXO4, are indispensable for SIRT1-dependent cell survival against oxidative stress, although deacetylation of p53 has also some role for cell protective function of SIRT1.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In Japan, four different types of hypotonic infusion fluids, namely, types 1–4, are available and used depending on the patient’s condition. Although branded and generic products for each type of ...hypotonic infusion fluid are available, their physicochemical properties are unknown. For types 1 and 3 fluids, differences in the physicochemical properties of branded and generic products lead to different adverse events when administered. In the present study, we measured titration acidity, pH, and osmolality of branded and generic type 2 hypotonic infusion fluids, which have recently been recognized as useful for maintenance infusion among pediatric patients. We herein assessed their physicochemical information required while selecting a product in clinical practice. Experiments were performed using one branded and two generic products of type 2 hypotonic infusion fluids. Titration acidity was measured via neutralization titration, osmolality was measured via freezing point depression, and pH was measured via potentiometry using a glass electrode. Significant differences in titration acidity, which is a risk factor for metabolic acidosis, and pH, which is a risk factor for pH-dependent changes upon mixing, were observed between the branded and generic products. Our study indicates that titration acidity and pH should be evaluated appropriately to avoid adverse events in clinical practice while selecting a product of type 2 hypotonic infusion fluids. Our findings highlight the importance of evaluating the differences between branded and generic products, specifically when selecting it for pediatric patients with incompletely developed renal function and patients with impaired renal function.
Size dependence of the boron (B) acceptor and phosphorus (P) donor levels of silicon (Si) nanocrystals (NCs) measured from the vacuum level was obtained in a very wide size range from 1 to 9 nm in ...diameter by photoemission yield spectroscopy and photoluminescence spectroscopy for B and P codoped Si-NCs. In relatively large Si-NCs, both levels are within the bulk Si band gap. The levels exhibited much smaller size dependence compared to the valence band and conduction band edges. The Fermi level of B and P codoped Si-NCs was also studied. It was found that the Fermi level of relatively large codoped Si-NCs is close to the valence band and it approaches the middle of the band gap with decreasing the size. The results suggest that below a certain size perfectly compensated Si-NCs, that is, Si-NCs with exactly the same number of active B and P, are preferentially grown, irrespective of average B and P concentrations in samples.
Muscular dystrophies are inherited myogenic disorders accompanied by progressive skeletal muscle weakness and degeneration. We previously showed that resveratrol (3,5,4'-trihydroxy-trans-stilbene), ...an antioxidant and activator of the NAD(+)-dependent protein deacetylase SIRT1, delays the progression of heart failure and prolongs the lifespan of δ-sarcoglycan-deficient hamsters. Because a defect of dystroglycan complex causes muscular dystrophies, and δ-sarcoglycan is a component of this complex, we hypothesized that resveratrol might be a new therapeutic tool for muscular dystrophies. Here, we examined resveratrol's effect in mdx mice, an animal model of Duchenne muscular dystrophy. mdx mice that received resveratrol in the diet for 32 weeks (4 g/kg diet) showed significantly less muscle mass loss and nonmuscle interstitial tissue in the biceps femoris compared with mdx mice fed a control diet. In the muscles of these mice, resveratrol significantly decreased oxidative damage shown by the immunostaining of nitrotyrosine and 8-hydroxy-2'-deoxyguanosine and suppressed the up-regulation of NADPH oxidase subunits Nox4, Duox1, and p47(phox). Resveratrol also reduced the number of α-smooth muscle actin (α-SMA)(+) myofibroblast cells and endomysial fibrosis in the biceps femoris, although the infiltration of CD45(+) inflammatory cells and increase in transforming growth factor-β1 (TGF-β1) were still observed. In C2C12 myoblast cells, resveratrol pretreatment suppressed the TGF-β1-induced increase in reactive oxygen species, fibronectin production, and expression of α-SMA, and SIRT1 knockdown blocked these inhibitory effects. SIRT1 small interfering RNA also increased the expression of Nox4, p47(phox), and α-SMA in C2C12 cells. Taken together, these findings indicate that SIRT1 activation may be a useful strategy for treating muscular dystrophies.
Abstract
Dipeptidyl peptidase-4 (DPP-4) plays a minor role in degrading vasoactive peptides that cause angioedema when angiotensin-converting enzyme (ACE) is present and fully functional. This study ...investigated the association between DPP-4 inhibitors (DPP-4Is) and angioedema, including cases where the concomitant use of ACE inhibitors (ACEIs) was absent. We obtained data from the US Food and Drug Administration Adverse Event Reporting System and performed a disproportionality analysis, using the reporting odds ratio (ROR) and information component (IC) for signal detection in patients aged ≥ 40 years, stratified by age group and sex. No signal was detected for DPP-4Is when the entire dataset was analyzed. However, a signal was detected for the entire female subset group, the three stratified female groups aged ≥ 60 years, and males in their 40 s. After excluding the data of concomitant ACEI users, most ROR and IC values were lower and significant only for females in their 60 s and males aged ≥ 80 years. Regarding individual DPP-4Is signals, those detected for saxagliptin and sitagliptin in some age groups disappeared after excluding the data of ACEI users. Notably, linagliptin was the only DPP-4I where signals were detected in most female groups, regardless of age and without concomitant ACEI use. Our findings suggest that some DPP-4Is were associated with a higher reporting of angioedema as per age and sex, even in the absence of concomitant ACEI use.
Purpose: Everolimus-induced diabetes mellitus (DM) outcomes include everolimus-resistant tumors and poor hyperglycemia outcomes, which lead to various other negative clinical outcomes. This study ...aimed to evaluate the effect of associations between concomitant drug treatment and time to DM event occurrence (onset or exacerbation) on the outcomes of everolimus-induced DM in patients with cancer. Methods: Data from the Japanese Adverse Drug Event Report database (JADER) were used, and patient drug use, time of DM event occurrence, and DM outcomes were determined from patient records. Associations between concomitant drug groups with everolimus and DM event occurrence were then evaluated for patients with both good and poor DM outcomes. Results: Top ten groups used concomitantly were drugs for the treatment of hypertension (HT), controlled DM, constipation, hypothyroidism, kidney disease, insomnia, hyperlipidemia, hyperuricemia, anemia, and gastritis. Among them, only HT, controlled DM, and hyperlipidemia were associated with DM event occurrence. These three drug groups were examined by the outcome of everolimus concomitant usage and revealed a significantly shorter time to DM event occurrence for patients with poor outcomes than for those with good outcomes (p = 0.015) among patients without a concomitant drug for DM. Each of these three drug groups was analyzed on patients who were concomitantly administered with one of each drug group with everolimus and revealed a significantly shorter time to DM event occurrence for patients with poor outcomes than for those with good outcomes in patients who received concomitant HT drugs (p = 0.006). Moreover, among the four HT drug categories, calcium channel blockers were significantly associated with poor outcomes (odds ratio, 2.18 1.09–4.34, p = 0.028). Conclusion: To prevent everolimus-induced poor DM outcomes, early DM detection and treatment are necessary, and the effect of the concomitant drug should be considered before initiating everolimus treatment.
Fractures are significantly associated with increased morbidity and mortality in older individuals; additionally, patients with diabetes mellitus are highly prone to fractures. The aim of the present ...study was to examine the association between dipeptidyl peptidase-4 (DPP-4) inhibitor use and the risk of fracture in older patients by analyzing data obtained from spontaneous adverse event reporting databases from the United States and Japan.
Data on older patients registered in the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) from the first quarter of 2013 to the end of 2019 and data registered in the Japanese Adverse Drug Event Report database (JADER) from April 2004 to December 2019 were used. Reporting odds ratio (ROR) and information component (IC) values were used for disproportionality analysis.
Significant inverse associations between DPP-4 inhibitor use and fracture were found for DPP-4 inhibitors as a whole (ROR = 0.80; 95% CI = 0.73 - 0.88; IC = -0.31, 95% CI = -0.46 to -0.17); linagliptin (ROR = 0.74; 95% CI = 0.59 - 0.94; IC = -0.42, 95% CI = -0.75 to -0.08); and sitagliptin (ROR = 0.77; 95% CI = 0.68 - 0.88; IC = -0.36, 95% CI = -0.55 to -0.17) in the analyses of FAERS data. Similarly, significant inverse associations were also found for DPP-4 inhibitors as whole (ROR = 0.71; 95% CI = 0.59 to 0.86; IC = -0.46, 95% CI = -0.74 to -0.18); sitagliptin (ROR = 0.70; 95% CI = 0.52 - 0.95; IC = -0.49, 95% CI = -0.93 to -0.05); and vildagliptin (ROR = 0.54; 95% CI = 0.35 - 0.83; IC = -0.85, 95% CI = -1.49 to -0.22) in the analyses of JADER data.
Our analysis of adverse event databases using different algorithms revealed that DPP-4 inhibitor use was inversely associated with fracture in older patients.
Charge transfer interaction between colloidal silicon (Si) quantum dots (QDs) and adsorbed molecules was investigated by means of photoluminescence (PL) spectroscopy. The molecule employed is ...tetrathiafulvalene (TTF), which has the highest occupied molecular orbital (HOMO) near that of Si QDs and can act as an electron donor to Si QDs. The energy difference between the HOMOs of TTF and Si QDs was controlled by changing the size of Si QDs. We found that the PL of Si QDs is strongly modified by the adsorption of TTF and that the PL change is reversible, that is, removal of TTF from a colloidal solution recovers the PL intensity. In the smallest Si QDs, where the HOMO level is expected to be 0.11 eV lower than that of TTF, a 2.5-fold enhancement of the PL was observed. The PL enhancement suggests that Si QDs having p-type behavior are compensated by electron transfer from TTF, similarly to the case of substitutional phosphorus doping in Si QDs. The observed size dependence of the PL enhancement factors suggests that the charge transfer process is described by classical Marcus theory.
In Japan, the increasing use of generic drugs has led to a reduction in drug prices, which affect the steady supply of drugs. A "basic drug" system was introduced to rescue these drugs by eliminating ...gaps in drug prices among preparations with the same constituents. "Type 1" hypotonic infusion fluids, which are potassium-free and commonly used to treat dehydration, meet the definition of a "basic drug" in Japan, and there are no drug price gaps. However, there is a lack of information on the physicochemical properties of "type 1" hypotonic infusion fluids, making it difficult to identify differences among them. Extracellular fluid-replacement solutions and "type 3" hypotonic infusion fluids have different pH and titratable acidity. Here, we measured the pH, titratable acidity, and osmolality of six different "type 1" hypotonic infusion fluids and compared the results with respect to risk avoidance considering metabolic acidosis, changes upon mixing, and vascular pain. There was a significant difference, or trend toward significance, in titratable acidity, which is a risk factor for metabolic acidosis in patients with impaired renal function, and pH, which is a risk factor for change upon mixing, among all combinations except one of the infusion fluids. Thus, the selection of "type 1" hypotonic infusion fluids for children with immature renal function, elderly patients with impaired renal function, and patients with unknown pathophysiology, considering titratable acidity and pH, is an effective strategy for risk avoidance.
Cardiomyopathy is the main cause of death in Duchenne muscular dystrophy. Here, we show that oral administration of resveratrol, which leads to activation of an NAD+-dependent protein deacetylase ...SIRT1, suppresses cardiac hypertrophy and fibrosis and restores cardiac diastolic function in dystrophin-deficient mdx mice. The pro-hypertrophic co-activator p300 protein but not p300 mRNA was up-regulated in the mdx heart, and resveratrol administration down-regulated the p300 protein level. In cultured cardiomyocytes, cardiomyocyte hypertrophy induced by the α1-agonist phenylephrine was inhibited by the overexpression of SIRT1 as well as resveratrol, both of which down-regulated p300 protein levels but not p300 mRNA levels. In addition, activation of atrial natriuretic peptide promoter by p300 was inhibited by SIRT1. We found that SIRT1 induced p300 down-regulation via the ubiquitin-proteasome pathway by deacetylation of lysine residues for ubiquitination. These findings indicate the pathological significance of p300 up-regulation in the dystrophic heart and indicate that SIRT1 activation has therapeutic potential for dystrophic cardiomyopathy.
Background: Dystrophin deficiency leads to life-threatening cardiomyopathy, whereas cardiac p300 promotes cardiac hypertrophy/failure.
Results: The SIRT1 activator resveratrol inhibited p300 protein up-regulation and attenuated cardiomyopathy in dystrophin-deficient mice, and SIRT1-induced p300 down-regulation was mediated via its deacetylation and ubiquitination.
Conclusion: SIRT1 activation ameliorates dystrophic cardiomyopathy by targeting p300.
Significance: Negative regulation of p300 is a novel cardioprotective mechanism of SIRT1.
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