Effect Of Nicotinamide Research Articles

Nicotinamide: Bright Potential in Glaucoma Management.

Glaucoma is a major cause of incurable ocular morbidity and poses significant challenges in its management due to the limited treatment options and potential adverse effects. Nicotinamide, a naturally occurring diet-rich nutrient, has emerged as a promising therapeutic agent for glaucoma, offering neuroprotective effects and the potential modulation of intraocular pressure (IOP) regulation pathways. This comprehensive review sought to analyze the current literature on nicotinamide in glaucoma management, exploring its mechanisms of action, efficacy, and safety profile. A systematic search of the PubMed database was conducted to identify relevant records on the therapeutic actions of nicotinamide in ocular hypertension and glaucoma. Publications evaluating nicotinamide's effects on retinal ganglion cells (RGCs), optic nerve function, IOP regulation, and neuroinflammatory pathways were included. The literature review revealed the preclinical evidence supporting nicotinamide's neuroprotective effects on RGCs, the preservation of optic nerve integrity, and the modulation of glaucoma-associated neuroinflammation. Additionally, nicotinamide may exert IOP-lowering effects through its influence on ocular blood flow and aqueous humor dynamics. Nicotinamide holds promise as a novel therapeutic approach in glaucoma management, offering potential neuroprotective and IOP-lowering effects. The authors recommend more research to determine the nicotinamide efficacy, safe dosing parameters, and any long-term safety concerns in glaucoma patients.

Nicotinamide restores tissue NAD+ and improves survival in rodent models of cardiac arrest.

Metabolic suppression in the ischemic heart is characterized by reduced levels of NAD+ and ATP. Since NAD+ is required for most metabolic processes that generate ATP, we hypothesized that nicotinamide restores ischemic tissue NAD+ and improves cardiac function in cardiomyocytes and isolated hearts, and enhances survival in a mouse model of cardiac arrest. Mouse cardiomyocytes were exposed to 30 min simulated ischemia and 90 min reperfusion. NAD+ content dropped 40% by the end of ischemia compared to pre-ischemia. Treatment with 100 μM nicotinamide (NAM) at the start of reperfusion completely restored the cellular level of NAD+ at 15 min of reperfusion. This rescue of NAD+ depletion was associated with improved contractile recovery as early as 10 min post-reperfusion. In a mouse model of cardiac arrest, 100 mg/kg NAM administered IV immediately after cardiopulmonary resuscitation resulted in 100% survival at 4 h as compared to 50% in the saline group. In an isolated rat heart model, the effect of NAM on cardiac function was measured for 20 min following 18 min global ischemia. Rate pressure product was reduced by 26% in the control group following arrest. Cardiac contractile function was completely recovered with NAM treatment given at the start of reperfusion. NAM restored tissue NAD+ and enhanced production of lactate and ATP, while reducing glucose diversion to sorbitol in the heart. We conclude that NAM can rapidly restore cardiac NAD+ following ischemia and enhance glycolysis and contractile recovery, with improved survival in a mouse model of cardiac arrest.

Cocrystallization with nicotinamide promotes naproxen photodegradation in the solid-state

In this study, we evaluated the photostability of a cocrystal of naproxen (NPX) and nicotinamide (NA) for the development of the photostabilization strategy. NPX photodegradation during ultraviolet-light (UV) irradiation was estimated by high-performance liquid chromatography (HPLC). The photostability of a NPX-NA cocrystal was less than NPX in the solid-state. Furthermore, NPX was photodegraded faster in the presence of NA at a higher concentration when the NPX-NA mixtures were UV-irradiated. The values of residual amounts of NPX in UV-irradiated NPX-NA cocrystal and mixture were 76.60 ± 3.85% and 70.06 ± 4.09%, respectively, which were significantly lower compared with that of UV-irradiated NPX powder (83.57 ± 2.15%). However, in the case that the effect of NA in the suspension of NPX was investigated, NA had no effect on NPX photodegradation. Residual amounts of NPX in UV-irradiated suspensions of NPX and NPX-NA cocrystal were comparable (33.13 ± 6.02% and 30.22 ± 2.09%, respectively). These results suggested that NA might promote NPX photodegradation only in the solid-state on account of that NA molecule could deliver the excitation energy to NPX molecule. This is the first study focused on the photochemical behavior of NPX-NA cocrystal and mixture and suggests that the presence of NA might induce the change of photostability of NPX in the powder form.

Nicotinamide Inhibits T Cell Exhaustion and Increases Differentiation of CD8 Effector T Cells.

Simple SummaryT cells that undergo repeated stimulation undergo a change called T cell exhaustion (TEx) that limits their ability to kill cancer cells and infections with microorganisms. The factors involved in the initiation and kinetics of these changes are poorly understood. In this research the authors have used an in-vitro model of repeated stimulation to investigate whether changes of TEx can be prevented by providing nicotinamide that is known to be integral in energy supply to cells. The model was found to be a good replicate of TEx changes such as upregulation of inhibitory receptors and down regulation of cytokines involved in killing of cancer. The results provide strong support for the notion that TEx results from poor energy supply from mitochondria due to generation of reactive oxygen species and that these changes can be prevented and reversed by treatment with nicotinamide. These findings appear to have important implications for treatment of cancers by immunotherapy.One of the limitations of immunotherapy is the development of a state referred to as T cell exhaustion (TEx) whereby T cells express inhibitory receptors (IRs) and lose production of effectors involved in killing of their targets. In the present studies we have used the repeated stimulation model with anti CD3 and anti CD28 to understand the factors involved in TEx development and treatments that may reduce changes of TEx. The results show that addition of nicotinamide (NAM) involved in energy supply to cells prevented the development of inhibitory receptors (IRs). This was particularly evident for the IRs CD39, TIM3, and to a lesser extent LAG3 and PD1 expression. NAM also prevented the inhibition of IL-2 and TNFα expression in TEx and induced differentiation of CD4+ and CD8 T cells to effector memory and terminal effector T cells. The present results showed that effects of NAM were linked to regulation of reactive oxygen species (ROS) consistent with previous studies implicating ROS in upregulation of TOX transcription factors that induce TEx. These effects of NAM in reducing changes of TEx and in increasing the differentiation of T cells to effector states appears to have important implications for the use of NAM supplements in immunotherapy against cancers and viral infections and require further exploration in vivo.

Nicotinamide Inhibits Self-renewal and Induces Granulocyte Differentiation of Multipotent Progenitor Cells.

Nicotinamide (NAM) a form of vitamin B3, is an essential precursor of NAD. This dinucleotide (pyridine nucleotide) participates in the regulation of fundamental processes including transcription, cell cycle progression and DNA repair. Here we assessed the effect of NAM on myeloid differentiation of the IL-3 dependent, multipotent hematopoietic progenitor cell line FDCP-Mix. We found that NAM reduces the pSTAT5 signaling response, cell cycling and self-renewal potential. It initiates an atypical program of myeloid differentiation that results in the emergence of granulocytic cells in the absence of added myeloid differentiation factors. NAM did not affect the expression the of cell surface granulocyte marker GR1 but led to a strong downregulation of MHC-II molecules. Taken together our data show that NAM induces a differentiation program in hematopoietic progenitors prompting them to undergo differentiation along the granulocyte path without reaching the status of fully developed granulocytes. Graphical abstract.

Poly (ADP-Ribose) polymerase-1 (PARP-1) overactivity plays a pathogenic role in bile acids-induced nephrotoxicity in cholestatic rats

Cholestatic liver disease is a clinical complication with a wide range of etiologies. The liver is the primary organ influenced by cholestasis. Other organs, rather than the liver (e.g., kidneys), could also be affected by cholestatic liver disease. Cholestasis-induced renal injury is known as cholemic nephropathy (CN). Although the structural and functional alterations of the kidney in cholestasis have been well described, the cellular and molecular mechanisms of CN are not well understood. Some studies mentioned the role of oxidative stress and mitochondrial impairment in CN. Several cellular targets, including proteins, lipids, and DNA, could be affected by oxidative stress. Poly (ADP-Ribose) polymerase-1 (PARP-1) is an enzyme that its physiological activity plays a fundamental role in DNA repair. However, PARP-1 overexpression is associated with enhanced oxidative stress and cell death. The current study was designed to evaluate the role of PARP-1 activity in the pathogenesis of CN. Bile duct ligated (BDL) rats were treated with nicotinamide (NA) as a PARP-1 inhibitor. Kidney, urine, and plasma samples were collected at scheduled time intervals (3, 7, 14, and 28 days after BDL surgery). Serum and urine biomarkers of kidney injury, markers of oxidative stress and DNA damage, PARP-1 expression and activity in the kidney tissue, inflammatory response, renal fibrosis markers, and kidney histopathological alterations were assessed. Significant changes in the serum and urine biomarkers of kidney injury were evident in the BDL rats. Markers of oxidative stress were increased, and tissue ATP levels and antioxidant capacity were decreased in the kidney of cholestatic animals. A significant increase in PARP-1 expression and activity was evident in BDL rats (3, 7, 14, and 28 days after BDL). Moreover, inflammatory response (IL-1β and TNF-α expression; and myeloperoxidase activity), renal tissue histopathological alterations, and kidney fibrosis (α-SMA and TGF-β expression, as well as collagen deposition) were detected in cholestatic animals. It was found that the PARP-1 inhibitor, NA (50 and 100 mg/kg, i.p), significantly mitigated cholestasis-induced renal injury. The positive effects of NA were more significant at a lower dose and the early stage of CN. These data indicate a pathogenic role for PARP-1 overexpression in CN.

Investigation of nicotinamide as more than an anti-phosphorus drug in chronic hemodialysis patients: a single-center, double-blind, randomized, placebo-controlled trial.

BackgroundHyperphosphatemia is a common complication of late-stage chronic kidney disease (CKD). Nicotinamide (NAM) has been reported as an adjunctive therapy for hyperphosphatasemia, but the effect of NAM on fibroblast growth factor 23 (FGF23) and Klotho has rarely been reported.MethodsWe randomly assigned 98 patients who underwent regular hemodialysis to received NAM (0.5–1.5 g per day, or 1–3 tablets per day) or placebo (1–3 tablets per day) as an add-on therapy of calcium-based phosphorus binders in a 1:1 ratio. All enrollments were followed-up for 52 weeks. We investigated the serum phosphorus as the primary outcome and serum FGF23 and Klotho as the secondary outcomes. Abdominal aortic calcification (AAC), which had a good correlation with coronary calcification was also compared between the two groups.ResultsIn total, 37 patients in the placebo group and 35 patients in the NAM group completed the 52-week follow-up. Compared with the placebo group, the NAM group showed a significant decrease of serum phosphorus at the 8th, 12th, 20th, 44th, and 52nd week. There was a declining trend of FGF23 and Klotho in both the placebo and NAM groups. Linear mixed models (LMMs) for overall comparisons by repeated measures of analysis of variance (ANOVA) revealed a significant decrease of FGF23 and slower declining rate of Klotho in the NAM group. No significant difference of AAC was detected between the two groups (P=0.805).ConclusionsNAM can not only further decrease the phosphorus level but also reduce the FGF23 level and slow down the descending rate of Klotho in chronic hemodialysis patients.

Diverse therapeutic efficacies and more diverse mechanisms of nicotinamide.

Nicotinamide (NAM) is a form of vitamin B3 that, when administered at near-gram doses, has been shown or suggested to be therapeutically effective against many diseases and conditions. The target conditions are incredibly diverse ranging from skin disorders such as bullous pemphigoid to schizophrenia and depression and even AIDS. Similar diversity is expected for the underlying mechanisms. In a large portion of the conditions, NAM conversion to nicotinamide adenine dinucleotide (NAD+) may be a major factor in its efficacy. The augmentation of cellular NAD+ level not only modulates mitochondrial production of ATP and superoxide, but also activates many enzymes. Activated sirtuin proteins, a family of NAD+-dependent deacetylases, play important roles in many of NAM's effects such as an increase in mitochondrial quality and cell viability countering neuronal damages and metabolic diseases. Meanwhile, certain observed effects are mediated by NAM itself. However, our understanding on the mechanisms of NAM's effects is limited to those involving certain key proteins and may even be inaccurate in some proposed cases. This review details the conditions that NAM has been shown to or is expected to effectively treat in humans and animals and evaluates the proposed underlying molecular mechanisms, with the intention of promoting wider, safe therapeutic application of NAM. NAM, by itself or through altering metabolic balance of NAD+ and tryptophan, modulates mitochondrial function and activities of many molecules and thereby positively affects cell viability and metabolic functions. And, NAM administration appears to be quite safe with limited possibility of side effects which are related to NAM's metabolites.

Nicotinamide Overcomes Doxorubicin Resistance of Breast Cancer Cells through Deregulating SIRT1/Akt Pathway.

Breast cancer is one of the leading causes of cancer deaths in female worldwide. Doxorubicin represents the most common chemotherapy for breast cancer, whereas side effects and development of resistance impede its effect on chemotherapy. Nicotinamide (NAM), serves as the sirtuins' inhibitor, effectively suppressing various types of cancer. However, the effects of NAM on drug resistance of breast cancer are need to be fully investigated. Breast cancer doxorubicin-resistant cells MCF-7/ADR and doxorubicin-sensitive cells MCF-7 were applied in this study. Cell proliferation was assessed by CCK8 and colony-forming assays. Cell migration was evaluated by scratch test and transwell assay while cell apoptosis was measured by TUNEL analysis. Expression levels of SIRT1, phosphate Akt (P-Akt, Ser-473) and Akt were measured using western blot analysis. The interrelation between SIRT1 and Akt was investigated by co-immunoprecipitation assay. Treatment of nicotinamide combined with doxorubicin effectively inhibited cell growth, suppressed cell migration, and promoted cell apoptosis of MCF7/ADR cells. Mechanistically, nicotinamide translocated SIRT1 from the cell nucleus to cytoplasm, dissociated the connection between SIRT1 and Akt, and consequently decreased expressions of SIRT1, and P-Akt, thereby inhibiting the growth of MCF7/ADR cells. Our results suggested that the value of nicotinamide is a potential therapeutic agent for breast cancer treatment through downregulating SIRT1/Akt pathway, leading to the valid management of breast cancer patients.

Nicotinamide reduces renal interstitial fibrosis by suppressing tubular injury and inflammation.

Renal interstitial fibrosis is a common pathological feature in progressive kidney diseases currently lacking effective treatment. Nicotinamide (NAM), a member of water‐soluble vitamin B family, was recently suggested to have a therapeutic potential for acute kidney injury (AKI) in mice and humans. The effect of NAM on chronic kidney pathologies, including renal fibrosis, is unknown. Here we have tested the effects of NAM on renal interstitial fibrosis using in vivo and in vitro models. In vivo, unilateral urethral obstruction (UUO) induced renal interstitial fibrosis as indicated Masson trichrome staining and expression of pro‐fibrotic proteins, which was inhibited by NAM. In UUO, NAM suppressed tubular atrophy and apoptosis. In addition, NAM suppressed UUO‐associated T cell and macrophage infiltration and induction of pro‐inflammatory cytokines, such as TNF‐α and IL‐1β. In cultured mouse proximal tubule cells, NAM blocked TGF–β‐induced expression of fibrotic proteins, while it marginally suppressed the morphological changes induced by TGF‐β. NAM also suppressed the expression of pro‐inflammatory cytokines (eg MCP‐1 and IL‐1β) during TGF‐β treatment of these cells. Collectively, the results demonstrate an anti‐fibrotic effect of NAM in kidneys, which may involve the suppression of tubular injury and inflammation.

Magnesium but not nicotinamide prevents vascular calcification in experimental uraemia.

Optimal phosphate control is an unmet need in chronic kidney disease (CKD). High serum phosphate increases calcification burden and is associated with mortality and cardiovascular disease in CKD. Nicotinamide (NA) alone or in combination with calcium-free phosphate binders might be a strategy to reduce phosphate levels and calcification and thus impact cardiovascular disease in CKD. We studied the effect of NA alone and in combination with magnesium carbonate (MgCO3) as a potential novel treatment strategy. CKD was induced in dilute brown non-agouti/2 mice by subtotal nephrectomy followed by a high-phosphate diet (HP) and 7 weeks of treatment with NA, MgCO3 or their combination. Control mice underwent subtotal nephrectomy and received an HP or underwent sham surgery and received standard chow plus NA. CKD mice showed increased serum fibroblast growth factor 23 and calcium-phosphate product that was normalized by all treatment regimes. NA alone increased soft tissue and vascular calcification, whereas any treatment with MgCO3 significantly reduced calcification severity in CKD. While MgCO3 supplementation alone resulted in decreased calcification severity, it resulted in increased intestinal expression of the phosphate transporters type II sodium-dependent phosphate transporter 1 (Pit-1). Combined therapy of MgCO3 and NA reduced tissue calcification and normalized expression levels of intestinal phosphate transporter proteins. In conclusion, the data indicate that NA increases while MgCO3 reduces ectopic calcification severity. Augmented expression of intestinal phosphate transporters by MgCO3 treatment was abolished by the addition of NA. However, the clinical relevance of the latter remains to be explored. Importantly, the data suggest no benefit of NA regarding treatment of calcification in addition to MgCO3.

130. Nicotinamide alleviates preeclampsia-like features and lupus nephritis in pregnant MRL/lpr mice treated with LPS

Introduction Systemic Lupus Erythematosus (SLE) increases the risk of unfavorable pregnancy outcomes including preterm birth and preeclampsia (PE). Flare-up of SLE during pregnancy or after birth is also problematic. TLR4 signaling is known to exacerbate both SLE and pregnancy. We have shown that nicotinamide (NAM), a non-teratogenic amide of vitamin B3, reduces inflammation and oxidative stress, and improves PE-like phenotype in mouse models of PE (Takahashi et al. PNAS 2016). Objective The aim of the present study is to establish a mouse model to study pathogenesis and treatment of SLE patients suffering from PE, and to test whether nicotinamide (NAM) is beneficial to preeclamptic SLE mice. Methods and results We administered low dose LPS, a TLR4 ligand, to pregnant lupus-prone MRL/lpr mice, and analyzed maternal and fetal outcomes. LPS increased blood pressure, caused fetal growth restriction (FGR), and exacerbated glomerulonephritis in MRL/lpr-LPS mouse. We conclude that this is a suitable model to study pathogenesis of pregnancy in SLE. We next examined a therapeutic effect of NAM on the pregnancy outcome and lupus nephritis in pregnant MRL/lpr mice given LPS. NAM (500 mg/kg) was administered on 13.5–17.5 dpc, and data and samples were collected on 18.5 dpc. NAM decreased maternal blood pressure, prolonged pregnancy period, and corrected FGR. NAM significantly improved glomerular injury and inflammatory cell infiltration, which was accompanied by reduced expression of inflammatory cytokines in their kidneys. NAM also decreased the level of plasma anti-dsDNA antibody and lymphadenopathy. Discussion NAM alleviates PE-like features, FGR, and lupus activity in MRL/lpr-LPS model. NAM may be a novel therapeutic option to benefit pregnant SLE patients.

A Novel Peptide, Nicotinyl⁻Isoleucine⁻Valine⁻Histidine (NA⁻IVH), Promotes Antioxidant Gene Expression and Wound Healing in HaCaT Cells.

Nicotinamide (NA), a water-soluble vitamin B3, has been shown to exert cellular-protective effects against reactive oxygen species (ROS). In order to improve the cellular-protective effects of NA, we synthesized a novel compound, nicotinyl–isoleucine–valine–histidine (NA–IVH), by combining NA with jellyfish peptides’ IVH. In the present study, we examined the cellular-protective effects of the novel synthetic nicotinyl-peptide, NA–IVH. We found that NA–IVH enhances the radical scavenging activity with a robust increase of the nuclear factor (erythroid-derived 2)-like factor (Nrf2) expression in human HaCaT keratinocytes. In addition, NA–IVH protected the cells from hydrogen peroxide (H2O2)-induced cell death. Interestingly, NA–IVH exhibited an improved wound-healing effect in a high glucose condition, possibly through the regulation of reactive oxygen species (ROS). Collectively, our results imply that a novel nicotinyl-peptide, NA–IVH, has a wound-healing effect in a hyperglycemic condition, possibly by modulating excessive ROS.

Metabolomics for the Effect of Biotin and Nicotinamide on Transition Dairy Cows.

The objective of this study was to evaluate alterations in serum metabolites of transition dairy cows affected by biotin (BIO) and nicotinamide (NAM) supplementation. A total of 40 multiparous Holsteins were paired and assigned randomly within a block to one of the following four treatments: control (T0), 30 mg/day BIO (TB), 45 g/day NAM (TN), and 30 mg/day BIO + 45 g/day NAM (TB+N). Supplemental BIO and NAM were drenched on cows from 14 days before the expected calving date. Gas chromatography time-of-flight/mass spectrometry was used to analyze serum samples collected from eight cows in every groups at 14 days after calving. In comparison to T0, TB, TN, and TB+N had higher serum glucose concentrations, while non-esterified fatty acid in TN and TB+N and triglyceride in TB+N were lower. Adenosine 5'-triphosphate was significantly increased in TB+N. Both TN and TB+N had higher glutathione and lower reactive oxygen species. Moreover, TB significantly increased inosine and guanosine concentrations, decreased β-alanine, etc. Certain fatty acid concentrations (including linoleic acid, oleic acid, etc.) were significantly decreased in both TN and TB+N. Some amino acid derivatives (spermidine in TN, putrescine and 4-hydroxyphenylethanol in TB+N, and guanidinosuccinic acid in both TN and TB+N) were affected. Correlation network analysis revealed that the metabolites altered by NAM supplementation were more complicated than those by BIO supplementation. These findings showed that both BIO and NAM supplementation enhanced amino acid metabolism and NAM supplementation altered biosynthesis of unsaturated fatty acid metabolism. The improved oxidative status and glutathione metabolism further indicated the effect of NAM on oxidative stress alleviation.

Nicotinamide is a specific inhibitor of dark-operative protochlorophyllide oxidoreductase, a nitrogenase-like enzyme, from Rhodobacter capsulatus

Dark-operative protochlorophyllide oxidoreductase (DPOR) is a nitrogenase-like enzyme consisting of two components, L-protein as a reductase component and NB-protein as a catalytic component. Elucidation of the crystal structures of NB-protein (Muraki et al., Nature 2010, 465: 110–114) has enabled us to study its reaction mechanism in combination with biochemical analysis. Here we demonstrate that nicotinamide (NA) inhibits DPOR activity by blocking the electron transfer from L-protein to NB-protein. A reaction scheme of DPOR, in which the binding of protochlorophyllide (Pchlide) to the NB-protein precedes the electron transfer from the L-protein, is proposed based on the NA effects.

Nicotinamide (NAM) Increases Surface Expression of CD62L On in Vitro Expanded NK Cells

AbstractAbstract 4355Natural killer (NK) cells comprise a critical component of the innate immune system that controls infections and tumor transformation. Although proof of principle supporting the antitumor effects of adoptively infused autologous and allogeneic NK cells has been established, overall response rates appear low, possibly related to their inability to traffic to lymphoid tissues and the bone marrow where hematological malignancies such as AML, lymphomas, and multiple myeloma reside. CD62L receptors play a critical role in the recruitment of NK cells from the circulation to the bone marrow and lymph nodes. Recently, investigators have developed a number of approaches to expand NK cells ex vivo for adoptive infusion in patients with cancer. Although NK cells cultured with irradiated EBV transformed lymphoblastoid cell lines (EBV-LCL) can be expanded by more than 1000 fold and are more cytotoxic to tumor cells compared to resting or IL-2 activated NK cells, these expanded cells undergo a substantial reduction in CD62L surface expression which could hinder their ability to be recruited into the tumor microenvironment. NAM, a specific inhibitor of NAD (+) dependent enzymes, was shown to up-regulate surface expression of CD62L on freshly isolated NK cells cultured in feeder cell-free cytokine-containing media. Based on this observation, we hypothesized that CD62L expression would be increased on NK cells expanded ex vivo using EBV-LCL feeders by adding NAM to the culture media. Methods:Human NK cells were isolated from PBMCs of 5 healthy volunteers by depleting CD3+ T cells and subsequently selecting CD56+ cells using immuno-magnetic beads. NK cells were expanded ex vivo in flasks over 21 days by co-culturing with an irradiated EBV-LCL feeder cell line at 20:1 LCL to NK cell ratio in media containing 500 IU/mL of IL-2. NAM was added to the media on culture day 7 at a 5 mM or 7.5 mM concentration and expanded NK cells were evaluated every 2–3 days by FACS to assess their phenotype and viability and by cytotoxicity assays to assess their cytotoxicity against K562 and renal cell carcinoma targets. The effects of NAM on the proliferative capacity of ex vivo expanded NK cultures were likewise assessed. Results:NK cell expansion cultures containing NAM had substantially higher CD62L surface expression compared to cultures without NAM, with this effect being most pronounced in NK cell cultures containing the higher concentration (7.5 mM) of NAM (see figure). On NK cell culture days 12, 14, 16, and 21, the surface MFI of CD62L was a median 1.62, 2.44, 2.03 and 3.65 fold higher on NK cells cultured in 7.5 mM of NAM compared to cultures without NAM (p =0.017, 0.012, 0.037 and 0.046 respectively; paired t-test). No significant difference in surface expression of NK cell TRAIL, NKG2D, NKG2A, NKp30, NKp46, KIR2DL1, KIR3DL1, KIR2DL2/DL3, CD44, CD95, and CD200R was observed between NAM containing cultures and controls although NKp44 expression was slightly higher in cultures that did not contain NAM. NAM-treated and untreated NK cells had similar cytotoxic function against K562 and renal cell carcinoma (RCC) tumor cell lines. The viability of NK cells, assessed by Trypan Blue and Annexin V staining, was unaffected by NAM. The addition of NAM to cell culture media did result in a dose-dependent reduction in ex vivo NK cell expansion: on days 14 and 16, NK cells expanded a median 926 and 2963 fold in control media compared to a median 443 and 1151 fold in media containing 5 mM NAM (p=0.0029 and 0.0074 respectively) and a median 359 and 732 fold in media containing 7.5 mM NAM (p=0.0019 and 0.0003 respectively). Although the proliferation of NK cells was reduced, ex vivo expansion of NK cells still occurred in NAM containing media with NK cells expanding a median 2785 and 1360 fold by day 18 in cultures containing 5 and 7.5 mM of NAM, respectively. Conclusion:The addition of NAM to NK cell expansion cultures substantially increased surface expression of CD62L on NK cells without any deleterious effect on their cytotoxic function. Although NAM reduced ex vivo NK cell proliferation, NK cells still expanded more than 1000 fold in NAM containing media. These data suggest NAM-induced increases in CD62L surface expression could be used as a novel method to improve the homing capacity of ex vivo expanded NK cells to the bone marrow and the lymphoid organs, potentially enhancing their antitumor effects when adoptively infused in patients with hematological malignancies. [Display omitted] Disclosures:Peled:Gamida Cell Ltd. Cell Therapy Technologies: Employment. Frei:Gamida Cell Ltd. Cell Therapy Technologies: Employment.

Nicotinamide, a SIRT1 inhibitor, inhibits differentiation and facilitates expansion of hematopoietic progenitor cells with enhanced bone marrow homing and engraftment

Strategies that increase homing to the bone marrow and engraftment efficacy of exvivo expended CD34(+) cells are expected to enhance their clinical utility. Here we report that nicotinamide (NAM), a form of vitamin B-3, delayed differentiation and increased engraftment efficacy of cord blood-derived human CD34(+) cells cultured with cytokines. In the presence of NAM, the fraction of CD34(+)CD38(-) cells increased and the fraction of differentiated cells (CD14(+), CD11b(+), and CD11c(+)) decreased. CD34(+) cells cultured with NAM displayed increased migration toward stromal cell derived factor-1 and homed to the bone marrow with higher efficacy, thus contributing to their increased engraftment efficacy, which was maintained in competitive transplants with noncultured competitor cells. NAM is a known potent inhibitor of several classes of ribosylase enzymes that require NAD for their activity, as well as sirtuin (SIRT1), class III NAD(+)-dependent-histone-deacetylase. We demonstrated that EX-527, a specific inhibitor of SIRT1 catalytic activity, inhibited differentiation of CD34(+) cells similar to NAM, while specific inhibitors of NAD-ribosylase enzymes did notinhibit differentiation, suggesting that the NAM effect is SIRT1-specific. Our findings suggesta critical function of SIRT1 in the regulation of hematopoietic stem cell activity and imply theclinical utility of NAM for exvivo expansion of functional CD34(+) cells.

Nicotinamide inhibits hepatic fibrosis by suppressing DNA synthesis and enhancing apoptosis of hepatic stellate cells

Liver fibrosis and its end-stage disease, cirrhosis, are major worldwide healthcare burdens. In this study, we evaluated the inhibitory effects of nicotinamide (NA) on rat hepatic fibrogenesis and investigated its underlying mechanism. We examined the inhibitory effects of NA in vivo by using F344 rats in a thioacetamide (TAA)-induced fibrogenesis model and assessed the inhibitory effects in vitro by using the rat hepatic stellate cell line THSC-Cl6. In vivo, NA significantly attenuated liver fibrosis in TAA-treated rats as assessed by histological analysis using hematoxylin-eosin and Masson's trichrome staining. In vitro, NA inhibited viability of THSC-Cl6 cells in a dose- and time-dependent manner, suppressed DNA synthesis, and induced apoptosis. Transcription of collagen mRNA and expression of alpha smooth muscle actin (the hallmark of activated hepatic stellate cells) were reduced by NA. Expression of the cell cycle-related proteins cyclin E, cyclin D1, and cyclin-dependent kinase (cdk)4, was reduced by NA treatment, but expression of cyclin A and cdk2 was not. Expression of the cdk inhibitors p16 and p21 was decreased by NA treatment, whereas expression of p27 was increased. It appears that NA inhibits rat hepatic fibrogenesis by suppressing DNA synthesis and enhancing apoptosis of hepatic stellate cells.

Nicotinamide Prevents Ultraviolet Radiation‐induced Cellular Energy Loss

UV radiation is carcinogenic by causing mutations in the skin and also by suppressing cutaneous antitumor immunity. We previously found nicotinamide (vitamin B3) to be highly effective at reducing UV-induced immunosuppression in human volunteers, with microarray studies on in vivo irradiated human skin suggesting that nicotinamide normalizes subsets of apoptosis, immune function and energy metabolism-related genes that are downregulated by UV exposure. Using human adult low calcium temperature keratinocytes, we further investigated nicotinamide's effects on cellular energy metabolism. We found that nicotinamide prevented UV-induced cellular ATP loss and protected against UV-induced glycolytic blockade. To determine whether nicotinamide alters the effects of UV-induced oxidative stress posttranslationally, we also measured UV-induced reactive oxygen species (ROS). Nicotinamide had no effect on ROS formation, and at the low UV doses used in these studies, equivalent to ambient daily sun exposure, there was no evidence of apoptosis. Hence, nicotinamide appears to exert its UV protective effects on the skin via its role in cellular energy pathways.

Chronic niacin overload may be involved in the increased prevalence of obesity in US children.

To investigate nicotinamide's action on glucose metabolism, and the association between niacin consumption and obesity prevalence. Dynamic nicotinamide's effect on plasma hydrogen peroxide and glucose metabolism was investigated using oral glucose tolerance tests with or without nicotinamide in the same five healthy subjects. Lag-regression analysis was used to examine the association between the niacin consumption and the obesity prevalence among US children using the data from the Economic Research Service of the US Department of Agriculture and from US Centers for Disease Control and Prevention, respectively. Compared with the control oral glucose tolerance test, the 1-h plasma hydrogen peroxide (1.4 +/- 0.1 micromol/L vs 1.6 +/- 0.1 micromol/L, P = 0.016) and insulin levels (247.1 +/- 129.0 pmol/L vs 452.6 +/- 181.8 pmol/L, P = 0.028) were significantly higher, and the 3-h blood glucose was significantly lower (5.8 +/- 1.2 mmol/L vs 4.5 +/- 1.1 mmol/L, P = 0.002) after co-administration of glucose and 300 mg nicotinamide. The obesity prevalence among American children increased with the increasing per capita niacin consumption, the increasing grain contribution to niacin due to niacin-fortification, and the increasing niacin-fortified ready-to-eat cereal consumption, with a 10-year lag. The regression analyses showed that the obesity prevalence in the US children of all age groups was determined by niacin consumption (R(2) = 0.814, 0.961 and 0.94 for 2-5 years, 6-11 years and 12-19 years age groups, respectively). The appetite-stimulating effect of nicotinamide appears to involve oxidative stress. Excess niacin consumption may be a major factor in the increased obesity prevalence in US children.