Targeting sirtuin activity with nicotinamide riboside reduces neuroinflammation in a GWI mouse model

Gulf War Illness (GWI) affects 30% of veterans from the 1991 Gulf War (GW), who suffer from symptoms that reflect ongoing mitochondria dysfunction. Brain mitochondria bioenergetics dysfunction in GWI animal models corresponds with astroglia activation and neuroinflammation. In a pilot study of GW veterans (n = 43), we observed that blood nicotinamide adenine dinucleotide (NAD) and sirtuin 1 (Sirt1) protein levels were decreased in the blood of veterans with GWI compared to healthy GW veterans. Since nicotinamide riboside (NR)-mediated targeting of Sirt1 is shown to improve mitochondria function, we tested whether NR can restore brain bioenergetics and reduce neuroinflammation in a GWI mouse model. We administered a mouse diet supplemented with NR at 100μg/kg daily for 2-months to GWI and control mice (n = 27). During treatment, mice were assessed for fatigue-type behavior using the Forced Swim Test (FST), followed by euthanasia for biochemistry and immunohistochemistry analyses. Fatigue-type behavior was elevated in GWI mice compared to control mice and lower in GWI mice treated with NR compared to untreated GWI mice. Levels of plasma NAD and brain Sirt1 were low in untreated GWI mice, while GWI mice treated with NR had higher levels, similar to those of control mice. Deacetylation of the nuclear-factor κB (NFκB) p65 subunit and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) was an increase in the brains of NR-treated GWI mice. This corresponded with a decrease in pro-inflammatory cytokines and lipid peroxidation and an increase in markers of mitochondrial bioenergetics in the brains of GWI mice. These findings suggest that targeting NR mediated Sirt1 activation restores brain bioenergetics and reduces inflammation in GWI mice. Further evaluation of NR in GWI is warranted to determine its potential efficacy in treating GWI.     

内脂素与妊娠期糖尿病

妊娠期糖尿病(gestational diabetes mellitus,GDM)是妊娠期首次发现或出现的不同程度的糖耐量受损.其发生率为1％～10％,可增加剖宫产率,导致巨大儿及肩难产等并发症.GDM以胰岛素抵抗为主,其病因相当复杂.内脂素是一种主要由内脏脂肪组织表达和分泌的肽类物质,在葡萄糖代谢方面发挥一定的作用.而其在人体中的病理生理作用尚存在争议,且大部分仍未被完全认识.最近研究表明,内脂素是与GDM发病机制密切相关的一种脂肪细胞因子,具有胰岛素样活性和炎症因子作用.     

Nicotinamide increases C-peptide secretion in patients with recent onset type 1 diabetes

Nicotinamide, a poly-(ADP-ribose) synthetase inhibitor, has been shown in animal models to induce islet B-cell regeneration. An open controlled trial was therefore carried out for 1 year in 36 patients with recent onset (less than 4 weeks symptoms) Type 1 diabetes. Twenty-three patients were treated with nicotinamide (200 mg daily) in addition to insulin, and 13 control patients were treated with insulin alone. Metabolic and immunological variables at entry were similar in the two groups. A significant increase of stimulated plasma C-peptide levels compared to diagnosis was observed only in the nicotinamide treated group (1.4 +/- 0.3 (+/- SE) micrograms l-1 at diagnosis vs 2.4 +/- 0.4 at 6 months, p less than 0.04; and 3.0 +/- 0.5 at 1 year, p less than 0.01). Patients receiving nicotinamide had lower glycosylated haemoglobin levels at 6 months and 1 year compared to the control group (p less than 0.04 and p less than 0.03, respectively) although insulin dose was lower. Small doses of nicotinamide may be successful in improving metabolic control in recent onset Type 1 diabetes, probably by increasing residual islet B-cell function.     

大鼠胰腺导管上皮细胞体外诱导分化

目的 探讨上皮细胞生长因子(EGF)、尼克酰胺(NIC)、肝细胞生长因子(HGF)、葡萄糖(Glu)、角脘蛋白生长因子(KGF)和β细胞素在大鼠胰腺导管上皮细胞体外诱导分化的作用.方法 采用健康SD大鼠胰腺导管上皮细胞,分于70个培养孔中,加入含有多种营养因子(不含血清)的PRMI 1640培养液中培养.每个孔中6种诱导剂均进行随机组合.在胰岛样细胞团(ICCs)形成前后的不同天数进行细胞计数、电镜观察、胰岛素测定以及免疫细胞化学和荧光分析.结果 胰腺导管上皮细胞培养7d后,单个贴壁上皮细胞分裂增殖,呈鹅卵石样细胞片,单层覆盖;加入诱导和促生长因子后,单层覆盖上皮细胞中逐渐产生一定数量类似胰岛样球状细胞团,直径为80～130μm.结论 6种促生长和诱导因子中,Glu、NIC、KGF、EGF作用较强;在所设定的浓度范围内,其作用均随着浓度的增加而增强.     

烟酰胺单核苷酸通过Sirt3减轻心脏死亡供肝诱导的缺血-再灌注损伤

目的  探讨烟酰胺单核苷酸（NMN）对大鼠心脏死亡供肝诱导的缺血-再灌注损伤（IRI）的作用及机制。方法  通过“磁环+双袖套”法建立大鼠原位肝移植模型。将SD大鼠随机分为假手术组（Sham组）、原位肝移植组（OLT组）、NMN处理+原位肝移植组（NMN组）、NMN+去乙酰化酶-3（Sirt3）抑制剂（3-TYP）+原位肝移植组（NMN+3-TYP组）。观察各组大鼠肝组织病理学改变及肝细胞凋亡情况,检测血清丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）水平,测定肝组织超氧化物歧化酶（SOD）和丙二醛（MDA）含量,检测肝组织Sirt3、微管相关蛋白1轻链3（LC3）Ⅱ、PTEN诱导假定激酶1（PINK1）、Parkin、线粒体外膜转位酶20（TOMM20）表达水平。分析各组大鼠术后生存情况。结果  与Sham组比较,OLT组ALT、AST水平升高;与OLT组比较,NMN组ALT、AST水平均下降;与NMN组比较,NMN+3-TYP组ALT、AST水平升高（均为P < 0.05）。Sham组大鼠肝组织结构基本正常;OLT组大鼠肝组织可见明显的淤血、空泡变性和肝细胞坏死等病理改变。OLT组Suzuki评分、细胞凋亡率较Sham组升高;NMN组Suzuki评分、细胞凋亡率较OLT组降低;NMN+3-TYP组Suzuki评分、细胞凋亡率较NMN组升高（均为P < 0.05）。与Sham组比较,OLT组SOD含量下降,MDA含量升高;与OLT组比较,NMN组SOD含量升高,MDA含量下降;与NMN组比较,NMN+3-TYP组SOD含量下降,MDA含量升高（均为P < 0.05）。与Sham组比较,OLT组Sirt3、TOMM20蛋白相对表达量下降,PINK1、Parkin、LC3Ⅱ蛋白相对表达量升高;与OLT组比较,NMN组Sirt3、PINK1、Parkin、LC3Ⅱ蛋白相对表达量升高,TOMM20蛋白相对表达量下降;与NMN组比较,NMN+3-TYP组PINK1、Parkin、LC3Ⅱ蛋白相对表达量下降,TOMM20蛋白相对表达量升高（均为P < 0.05）。Sham组、OLT组、NMN组、NMN+3-TYP组大鼠术后7 d生存率分别为100%、50%、75%、58%。结论  NMN可通过上调Sirt3,增强肝脏抗氧化能力及诱导PINK1/Parkin介导的线粒体自噬,减轻肝IRI,从而对心脏死亡供肝发挥保护作用。     

复方叶酸B_(12)注射液导数光谱测定法

复方叶酸B_(12)注射液在江苏省药品质量标准中只测定叶酸含量,用还原-重氮化-偶合-比色法,操作步骤多,易造成误差。本文采用紫外分光光度法直接测定叶酸含量,并用一阶导     

RP－HPLC法测定复合维生素B片中维生素B_1、B_2、B_6和烟酰胺的含量

用ＲＰ－ＨＰＬＣ法（固定相为μＢｏｎｄｐａｋＣ１８柱,流动相为己烷磺酸钠冰醋酸液,紫外检测波长为２８０ｎｍ）同时测定出复合维生素Ｂ片中四个组分的含量,方法专属性强,省时;维生素Ｂ１、Ｂ２、Ｂ６和烟酰胺的平均回收率和平均相对标准偏差分别为１００．５％,２．０％;９８．０％,１．９％;１０１．８％,１．１％;１００．１％,２．１％（ｎ＝３）。     

Evidence for increased NADPH-diaphorase-positive neurons in the central auditory system of the aged rat

Conclusions: The age-related increase in the production of nitric oxide (NO) suggests that this increase was related to neuron aging. Additional studies may provide information regarding aging-related changes in the central auditory system. Objectives: Although NO has been associated with aging, it is unclear whether specific areas of the central auditory system are involved. We therefore assayed aging-related changes in NADPH-diaphorase (NADPH-d), a selective histochemical marker for NO, in the neurons of the central auditory system and other brain regions. Materials and methods: The numbers of NADPH-d-stained neurons and the area and staining density of cell bodies were examined in aged (24 months old) and younger (4 months old) Wistar rats. Results: The number of NADPH-d-positive neurons in the inferior colliculus was significantly increased in aged rats (p<0.05), whereas the area of NADPH-d-positive neurons in all areas did not differ significantly between aged and younger rats (p>0.05). The staining densities of NADPH-d-positive neurons in the inferior colliculus, the auditory cortex, and the visual cortex were significantly greater in aged compared with younger rats (p<0.05).     

烟酰胺对光老化皮肤真皮羟脯氨酸含量的影响

目的 初步探讨烟酰胺对紫外线（UV）所致光老化皮肤真皮羟脯氨酸（HP）含量是否有影响。方法 利用无毛昆明种小鼠动物模型模拟慢性工期紫外线照射所致的皮肤光老化，采用UVB和UVA混合光源，经17周剂量由1MED渐增至3MED的紫外线照射背部皮肤，然后观察15周，测定真皮HP含量。分组方法：非紫外线照射组（不施加任何处理因素）；烟酰胺组（照射紫外线结束30min后，0.2mol/L烟酰胺丙酮溶液200μl涂抹于小鼠背部皮肤，每周2次）；丙酮对照组（照射紫外线30min后，90％丙酮溶液200μl涂抹小鼠背部皮肤，每周2次）；紫外线照射组（仅照射紫外线）。结果 小鼠背部皮肤HP含量烟酰胺组明显高于紫外线照射和丙酮对照组（P＜0．01）。各组腹部真皮HP含量差异均无显著性（P＞0．05）。非紫外线照射组，烟酰胺组背，腹真皮HP含量自身比较差异均无显著性，而紫外线照射组，丙酮对照组 ，腹真皮HP含量差异有显著性（P＜0．01），腹部明显高于背部。结论 皮肤涂抹烟酰胺可抵抗由皮肤光老化引起真皮HP含量降低。