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The cofactor nicotinamide adenine dinucleotide (NAD+) plays a key role in a wide range of physiological processes and maintaining or enhancing NAD+ levels is an established approach to enhancing healthy aging. Recently, several classes of nicotinamide phosphoribosyl transferase (NAMPT) activators have been shown to increase NAD+ levels in vitro and in vivo and to demonstrate beneficial effects in animal models. The best validated of these compounds are structurally related to known urea-type NAMPT inhibitors, however the basis for the switch from inhibitory activity to activation is not well understood. Here we report an evaluation of the structure activity relationships of NAMPT activators by designing, synthesising and testing compounds from other NAMPT ligand chemotypes and mimetics of putative phosphoribosylated adducts of known activators. The results of these studies led us to hypothesise that these activators act via a through-water interaction in the NAMPT active site, resulting in the design of the first known urea-class NAMPT activator that does not utilise a pyridine-like warhead, which shows similar or greater activity as a NAMPT activator in biochemical and cellular assays relative to known analogues.
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【Objective】 To explore the role of visfatin-nicotinamide phosphoribosyl transferase （Nampt） axis in the progression of epithelial ovarian cancer （EOC） and its effect on the patients’ prognosis. 【Methods】 Immunohistochemical analysis was used to detect the expression of Nampt protein in tissues from epithelial ovarian cancer and normal ovary； ELISA was used to determine the level of visfatin in serum. Then the two were further analyzed to estimate their effects on clinicopathological characteristics and the EOC patients’ overall survival. 【Results】 The mean level of serum visfatin in these EOC patients was significantly elevated compared with that of the patients with benign ovarian tumors and normal population. ROC curve analysis showed that the area under curve （AUC） of serum visfatin for diagnosis of EOC was 0.744， with a cut-off value of 5.95 ng/mL. Serum visfatin of the EOC patients was related to T， N and FIGO stage （P<0.05）， and was positively correlated with CA125 （rs=0.389， P=0.001）. The rate of Nampt positive expression in tissues from EOC was significantly increased and correlated with FIGO stage and serum visfatin （P<0.05）. Nampt protein expression in EOC was positively correlated with serum visfatin level （rs=0.55， P<0.001）. The 1-year， 3-year and 5-year survival rate of these patients with EOC was 98.6%， 74.3% and 34.3%， respectively. Survival analysis demonstrated that the overall survival of these patients was related to T， N， FIGO stage， serum visfatin and Nampt expression in EOC， and both FIGO stage and Nampt expression were independent prognostic factors （P<0.05）. 【Conclusion】 The overall survival of these EOC patients was related to T， N， FIGO stage， serum visfatin and Nampt expression， and FIGO stage and Nampt expression are independent factors predicting the outcome. This highlights that visfatin-Nampt axis promotes the progression of epithelial ovarian cancer and affects the prognosis of EOC patients.
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Objective To investigate the effects of nicotinamide phosphoribosyl transferase (NAMPT) inhibitor FK866 on polymicrobial sepsis-induced liver injury in mice. Methods Eighty-four healthy male C57BL/6J mice were divided into four groups by random number table method (n = 21): sham group, sepsis-induced liver injury model by cecal ligation and perforation group (CLP group), vehicle+CLP group and FK866+CLP group. FK866 (10 mg/kg) or same volume dimethyl sulfoxide were given intraperitoneally into mice 24, 12 and 0.5 hours prior to CLP in the FK866+CLP group or the vehicle+CLP group, respectively. Fifteen mice in each group were used to observe the 48-hour survival after operation. The remaining 6 mice were sacrificed 20 hours after operation to harvest venous blood and liver tissue samples for index detection. The levels of serum alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured by colorimetry; the levels of serum NAMPT, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by enzyme linked immunosorbent assay (ELISA); the mRNA expressions of TNF-α and IL-6 were measured by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR); the protein expressions of hepatic NAMPT, cytoplasmic IκBα and nuclear factor-κB (NF-κB) were measured by Western Blot. Results Compared with the sham group, the 48-hour survival in the CLP group was significantly decreased; serum and liver NAMPT protein levels were significantly increased, serum ALT, AST, TNF-α, IL-6 levels and mRNA expressions of TNF-α, IL-6 in liver tissue were significantly increased; the expression of cytoplasmic IκBα protein was significantly decreased, and the expression of nuclear NF-κB protein was significantly increased; which indicated that CLP induced NF-κB activation, inflammation and liver injury. There was no significant difference between the vehicle+CLP group and the CLP group. Compared with the vehicle+CLP group, the 48-hour survival in FK866+CLP group was significantly increased (53.33% vs. 26.67%); serum ALT, AST, TNF-α, IL-6 levels and mRNA expressions of TNF-α, IL-6 in liver tissue were significantly decreased [serum ALT (U/L): 128.94±32.48 vs. 237.24±58.61, serum AST (U/L):289.89±68.74 vs.468±82.17, serum TNF-α (pg/L): 65.17±18.74 vs.127.64±48.18, serum IL-6 (ng/L): 31.78±5.23 vs. 60.87±13.12, liver TNF-α mRNA (2-ΔΔCt): 8.37±4.17 vs. 18.24±6.12, liver IL-6 mRNA (2-ΔΔCt): 18.58±7.12 vs.34.24±6.71], the expression of cytoplasmic IκBα protein was significantly increased (IκBα/GAPDH: 0.23±0.03 vs. 0.12±0.04), while expression of nuclear NF-κB protein was significantly decreased (NF-κB/Lamin B1: 0.25±0.04 vs. 0.42±0.05), with statistically significant differences (all P < 0.05). Conclusion NAMPT inhibitor FK866 protects polymicrobial sepsis-induced liver injury via the inhibition of NF-κB activation and inflammation.
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Objective To study the expression of nicotinamide phosphoribosyl transferase (Nampt) in breast cancer and to investigate the effects of Nampt inhibitor on the growth and chemotherapy sensitivity of breast cancer cells.Methods Nampt mRNA expression in breast cancer tissues and adjacent normal tissues was detected by qRT-PCR method.The effect of Nampt inhibitor on the growth of breast cancer cells and chemotherapy sensitization was detected by MTT and soft agar clonogenic assays.Results Nampt in breast cancer was significantly higher than that in normal breast tissue (P=0.000).Nampt inhibitor FK866 repressed breast cancer cell proliferation (24 h,P=0.003;48 h,P=0.001) and suppressed cell anchorage-independent growth (0.3 nM vs 0 nM,P=0.02;3 nM vs 0.3 nM,P=0.0143;0 nM vs 3 nM,P=0.02).FK866 also increased the chemo-sensitivity of breast cancer cells to fluorouracil by greater inhibition of cell proliferation.Conclusion Our findings indicate that Nampt may be a new therapeutic target for breast cancer.
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AIM: The aim of this study was to assess visfatin expression and its effect on human telomerase gene expression in AGS gastric cancer cell line. MATERIALS AND METHODS: In this study, human gastric cancer (AGS) cell line was established as an in vitro model. Reverse transcription polymerase chain reaction (RT‑PCR) and enzyme‑linked immunosorbent assay was performed to show that visfatin expression in messenger ribonucleic acid (mRNA) and protein level respectively. After stimulating with increasing concentrations of visfatin for times of 24 h and 48 h, cell proliferation was assessed by 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide (XTT) assay. In order to investigate telomerase gene expression affected by visfatin in AGS cell line, total RNA was extracted and complementary deoxyribonucleic acid was synthesized buy using commercially available kits. Expression of human telomerase reverse transcriptase (hTERT) mRNA was carried out by real‑time RT‑PCR. RESULTS: After visfatin treatment gastric cell line proliferation was enhanced and was increased the expression of hTERT. CONCLUSIONS: The obtained data showed that visfatin induces endogenously gastric cancer cell proliferation and increases telomerase (hTERT) gene expression, as a cancer gene. Based on this study, it is suggested that expression of this adipocytokine protein in real samples could be biomarker for gastric cancer.
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Objective To investigate the effects of metformin on serum visfatin and the level of visfatin mRNA in visceral adipose tissue of type 2 diabetic rats.Methods Forty Wistar rats were randomly assigned into normal diet group (NC) and diabetic group.The rats in the diabetic group were fed with high glucose and high fat diet, and then injected with streptozotocin (STZ).The diabetic rats were divided into diabetic control (DC), metformin (MET), and insulin-treatment (INS) groups.Eight weeks later, body weight (BW) , visceral adipose tissue weight, and biochemical indicators were assessed.Homeostasis model assessment of insulin resistance (HOMA-IR) and Lee index were calculated.The serum visfatin levels were detected by enzyme-linked immunoassay (EIA), and the visfatin mRNA levels of visceral adipose tissues were detected by real time polymerase chain reaction (PCR).Results Compared to group DC, the visfatin levels of serum and visceral adipose tissue mRNA were lower in INS group, but did not have significant difference (P ＞ 0.05);the visfatin levels of serum and visceral adipose tissue mRNA in MET group were significantly lower (P ＜ 0.01).Conclusions Metformin can reduce the visfatin levels of serum and visceral adipose tissue mRNA, and improve the insulin resistance in type 2 diabetic rats.
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Objective To study the effects of benzyl propionate nandrolone (BPN ) on the nicotinamide phosphoribosyl transferase (Nampt), insulin receptor substeate-2 (IRS-2 )and pancreatic duodenal homeobox-1 (PDX-1)expressions, cell cycle changes as well as insulin secretion in pancreatic islet cell NIT-1 lines, and to explore the influence of BPN in the Nampte xpression in NIT-1 cells and insulin signaling molecules in high glucose oxidation stress.Methods The NIT-1 cells were cultured with different concentrations (5.6,11.1,16.7,and 27.6 mmol·L-1)of glucose,then they were treated with 10 mg·L-1 BPN for 48 h with no BPN treatment as corresponding control groups.The expression levels of Nampt,IRS-2,and PDX-1 were tested by Western blotting assay.The changes of cell cycle were determined by FCM and the cell insulin secretion levels were measured with radioimmunoassay.Results Compared with corresponding control groups,the expression levels of Nampt,IRS-2, and PDX-1 proteins in the NIT-1 cells in various BPM groups were increased (P<0.05 or P<0.01).The G0/G1 phase arrest was relieved (P<0.01)when the cells was cultured in low glucose (5.6 mmol·L-1 )condition,and the G2/M block was remitted significantly in high glucose (27.6 mmol·L-1 )condition (P<0.01),furthermore, the cell insulin secretion was promoted compared with control groups except 1 1.1 mmol· L-1 glucose group (P<0.01).Conclusion BPN can promote the expression levels of Nampt,ISR-2 and PDX-1 proteins in NIT-1 cells. There is close relationship between the Nampt expression in NIT-1 cells and insulin signaling pathway and BPN prevents the cells from insulin resistance.
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Objective To study the expressions of nicotinamide phosphoribosyl transferase (Nampt)in main energy metabolism organs (liver, pancreas, skeletal muscle, and kidney ) of the rats with type 2 diabetes mellitus (T2DM),and to explore the correlation between the expression and distribution of Nampt and the occurrence of diabetes.Methods The SD rat diabetes model was established by injecting with streptozotcin (STZ).The SD rats were randomly divided into diabetes group and control group. Immunohistochemical Envision staining assay was used to detect the distribution and protein expressions of Nampt in liver,pancreas,muscle,and kidney tissues of the rats,at the same time the blood glucose and serum insulin levels were also be detected. Results The blood glucose level of the rats in diabetes group was significantly higher than that in control group (P<0.01),and the fasting insulin level was lower than that in control group (P<0.01).The Nampt expression in the liver tissue of the rats in diabets group was significantly increased,which distributed near the hepatic sinus in diabetes rats,and the Nampt expression was also increased in skeletal muscle in which the whole cell was thick dying;the Nampt expression mainly distributed in the renal tubular epithelial cells. Compared with control group, the positive expression rates of Nampt in liver,skeletal muscle,and kidney tissues of the rats in diabets group were significantly increased (P<0.05 or P<0.01).There was nearly no Nampt expression in pancreas tissue of the rats in diabetes group and the Nampt expression level was significantly lower than that in control group (P<0.01). Conclusion The Nampt expressions are much different in main energy metabolic organs of the rats with diabetes.It is suggested that Nampt may be used as a specific indicative marker in the process of diabetes.