Ethylene and Spermidine in Wheat Grains in Relation to Starch Content and Granule Size Distribution Under Water Deficit

Two wheat cultivars （Triticum aestivum L.） were used to evaluate the effects ofpost-anthesis severe water deficit （SD） on starch content and granule size distribution and their relations with ethylene and spermidine （Spd）. Comparison to the well-watered （WW） treatment, SD led to lower Spd and higher 1-aminocylopropane-l-carboxylic acid （ACC） concentrations and ethylene evolution rate （EER） in grains at the critical stage of forming starch granules. Application of Spd or aminoethoxyvinylglycine （AVG） significantly reduced ACC concentration and EER and increased Spd concentration, while ethephon or methylglyoxal-bis （MGBG） had an opposite impact. The volume and surface area distribution of starch granules showed a bimodal curve, while the number distribution exhibited a unimodal curve. SD caused a marked drop in grain weight, grain number and starch content, also led to a significant reduction in the proportion （both by volume and by surface area） of B-type starch granules （〈10 Ixm）, with an increase in those of A-type starch granules （〉10 ~tm）. Application of Spd or AVG increased the proportion （both by volume and by surface area） of B-type starch granules under SD. Correlation analysis suggested that ethylene and Spd showed an antagonism relation in the formation of B-type granules. These results suggested that it would be good for the formation of B-type starch granules to have the physiological traits of higher Spd and lower ACC concentrations and ethylene emission under SD.

Effect of Ice-Temperature and Spermidine on Chilling Sensitivity of Pepper

The peppers which were treated at ice-temperature for 6 hours and 1 mmol/L spermidine for 10 min, followed by cold storage (4℃ ± 1℃) respectively were investigated. The results indicated that the chilling injury was delayed and reduced by ice-temperature and spermidine treatments. Comparing with control group, ice-temperature and spermidine exerted significant effects on reduction of ascorbic acid (Vc) and chlororphyll contents, relatively high activity of superoxide dismutase (SOD), accumulation of malondialdehyde (MDA) as well as the increase of cell membrane penetrability. The results indicated that the spermidine and ice-temperature induced the activity of antioxidant enzyme SOD and maintained higher defence-related compound Vc as well as lower levels of membrane lipid peroxidation, which may be associated with chilling injury alleviation. There was a difference between ice-temperature treatment and spermidine treatment after 30 days. The results suggested that spermidine was more effective in reducing chilling sensitivity and prolonging storage of peppers.

Differential Proteins Expressed in Rice Leaves and Grains in Response to Salinity and Exogenous Spermidine Treatments

Exogenous application of spermidine（Spd） has been reported to modulate physiological processes and alleviate salt-induced damage to growth and productivity of several plants including rice. Employing a proteomic approach, we aimed at identifying rice leaf and grain proteins differentially expressing under salt stress, and in response to Spd prior to Na Cl treatment. A total of 9 and 20 differentially expressed protein spots were identified in the leaves of salt-tolerant（Pokkali） and saltsensitive（KDML105） rice cultivars, respectively. Differential proteins common to both cultivars included a photosynthetic light reaction protein（oxygen-evolving complex protein 1）, enzymes of Calvin cycle and glycolysis（fructose-bisphosphate aldolase and triose-phosphate isomerase）, malate dehydrogenase, superoxide dismutase and a hypothetical protein（Os I_18213）. Most proteins were present at higher intensities in Pokkali leaves. The photosynthetic oxygen-evolving enhancer protein 2 was detected only in Pokkali and was up-regulated by salt-stress and further enhanced by Spd treatment. All three spots identified as superoxide dismutase in KDML105 were up-regulated by Na Cl but down-regulated when treated with Spd prior to Na Cl, indicating that Spd acted directly as antioxidants. Important differential stress proteins detected in mature grains of both rice cultivars were late embryogenesis abundant proteins with protective roles and an antioxidant protein, 1-Cys-peroxiredoxin. Higher salt tolerance of Pokkali partly resulted from higher intensities and more responsiveness of the proteins relating to photosynthesis light reactions, energy metabolism, antioxidant enzymes in the leaves, and stress proteins with protective roles in the grains.

Exogenous Spermidine Promotes Somatic Embryogenesis of Cunninghamia lanceolata by Altering the Endogenous Phytohormone Content

In order to study how exogenous hormones in C.lanceolata(gymnosperm)regulate somatic embryogenesis,we measured the endogenous phytohormones of two genotypes with different somatic embryogenesis efficiency and found that an increase in endogenous concentrations of IAA and ABA may be correlated to more efficient somatic embryogenesis.By applying exogenous spermidine,we found that exogenous hormones may affect somatic embryogenesis efficiency through affecting the endogenous phytohormone content.Based on these results,further studies can be conducted whereby the concentration of exogenous hormones or the levels of endogenous phytohormones by molecular methods are regulated to promote somatic embryogenesis.Our research may benefit the long-term economic output of the forestry industry and lays the foundation to studying the molecular mechanism that controls somatic embryogenesis efficiency.

PRODUCTION AND APPLICATION OF MONOCLONAL ANTIBODY TO POLYAMINE (PREPARATION AND CHARACTERISTICS OF MONOCLONAL ANTIBODIES AGAINST SPERMIDINE)

A monoclonal antibody was first prepared by fusion of mouse myeloma cells (SP2/0-Ag-14) with spleen cells isolated from male BALB/ c mice immunized with spermidine-bovine serum albumin conjugate (SPD- BSA). The hybridoma cell line producing antibody specific for spermidine was cultured in vitro and after i. p. into mice, the ascitic fluid gave suitably high dilution titres (1: 106) by enzyme immunoassay. This monoclonal antibody is of IgG1 class and the bimolecular compleex with molecular weight of 52KD and 27 KD. The monoclonal antibody was clearly specific to spermidine comparing with spermine or putriscine. Monclonal antibody may prove to be useful in the rapid diagnosis and evaluation of patients with cancer.

Potent trophic activity of spermidine supramolecular complexes in in vitro models

AIM:To test the growth-promoting activity of the polyamine spermidine bound to various polymeric compounds in supramolecular complexes.METHODS:A thiazolyl blue cell viability assay was used to determine the growth-promoting potency of spermidine-supramolecular complexes in a human skin fibroblast cell line exposed to spermidine and different spermidine-supramolecular complexes that were obtained by combining spermidine and polyanionic polymers or cyclodextrin.Reconstituted human vaginal epithelium was exposed to a specific spermidinesupramolecular complex,i.e.,spermidine-hyaluronan(HA)50,and cell proliferation was determined by Ki-67immunohistochemical detection.Transepithelial electrical resistance and histological analysis were also performed on reconstituted human vaginal epithelium to assess tissue integrity.RESULTS:The effect of spermidine and spermidinesupramolecular complexes was first tested in skin fi-broblasts.Spermidine displayed a reverse dose-related mode of activity with mmol/L growth inhibition,whereas 30%stimulation over basal levels was detected at mol/L and nmol/L levels.Novel spermidine-supramolecular complexes that formed between spermidine and polyanionic polymers,such as HA,alginate,and polymaleate,were then tested at variable spermidine concentrations and a fixed polymer level(0.1%w/v).Spermidine-supramolecular complexes stimulated the cell growth rate throughout the entire concentration range with maximal potency(up to 80%)at sub-mol/L levels.Similar results were obtained with spermidine-(-cyclodextrin),another type of spermidine-supramolecular complex.Moreover,the increased expression of Ki-67 in the reconstituted human vaginal epithelium exposed to spermidine-HA 50 showed that the mode of action behind the spermidine-supramolecular complexes was increased cell proliferation.Functional and morphological assessments of reconstituted human vaginal epithelium integrity did not show significant alterations after exposure to spermidine-HA,thus supporting its safety.CONCLUSION:Spermidine found in spermidine-supramolecular complexes displayed potentiated regenerative effects.Safety data on reconstituted human vaginal epithelium suggested that assessing spermidinesupramolecular complex efficacy in atrophic disorders is justified.

Clinical Significance of Topical Spermidine Hyaluronate in Vestibulodynia: An Early Appraisal

Background: The most common subtype of chronic vulvar pain is provoked vestibulodynia. The entry of the vagina is the site of acute and recurrent pain in this highly prevalent and debilitating condition, which is characterized by pressure application or attempted vaginal penetration. The aim of this study was to determine the effectiveness of topical spermidine in patients with vestibulodynia. Methods: Topical gels containing spermidine in hyaluronate complexes Ubi1 and Ubi2 endowed with differentiated release ratio and viscosity were applied at 3 doses/week during 4-weeks, then at 2 doses/week during the next 4-weeks in two groups of patients. Pain relief was measured by visual analogic score (VAS) and dyspareunia score expressed as percent improvement from baseline to posttreatment. Results: Group 1 treated with Ubi1 provided improvement in pain (46%) and dyspareunia (27%). However, the treatment in Group 2 resulted in a superior amelioration: VAS of pain (76%) and dyspareunia (50%) as Ubi2 gel provided higher dose and viscosity along with improved local application. Conclusions: Our results demonstrated that preparation 2 resulted in greater reduction in symptoms as compared to preparation 1 as measured by the VAS and Marinoff scale. These early, yet outstanding clinical outcomes in vestibulodynia through to the stimulation of tissue mechanosensor and their relevant downstream effects are reviewed hereafter.

SPERMIDINE RADIOIMMUNOASSAY IN MONITOR OF PRECANCEROUS LESIONS OF ESOPHAGUS

Serum spermidine was assayed by radioimmuno-assay in different stages of esophageal carcinogenesis in the population from high risk area of esophageal cancer, Linxian County. The serum spermidine values were 76.94+74.38 ng ml in 36 normal individuals; 115.71+113.45 ng/ml in 35 patients with marked epithelial hyperplasia (MEH) and 294.48+135.36 ng/ml in 31 patients with early esophageal cancer. Patients with MEH were given intervention treatment by Aminoretinoic Ester or Anticancer B or placebo (starch) as controls. One year later, samples from the population were collected again for serum spermidine msasurement. The values were 95.8+ 68.2 ng/ml in 27 normals; 125.1±72.9 ng/ml in 62 patients with MEH treated by Anticancer B; 125.6± 117.2 ng/ml in 64 patients with MEH treated by Aminoretinoic Ester; 162.4±76.6 ng/ml in 62 controls and 210.5±182.9 ng/ml in 44 patients with early esophageal cancer.The results showed that spermidine radioim-munoassay could reflect the tendency of esophageal precancerous changes toward cancer or back to normal. They can be taken as a mid-way monitor indicator for tumor-blocking drugs. Also, it could be of value in the early diagnosis of esophageal cancer.

外源亚精胺对淹水胁迫下地毯草形态和生理特性的影响

本研究以地毯草(Axonopus compressus)为材料,采用双套盆法,以土层与淹水齐平作为胁迫条件,研究淹水胁迫下喷施1 mmol/L亚精胺(Spd)对地毯草幼苗不同时间的生长及其相关生理指标的影响。结果表明,施加Spd可提高地毯草淹水幼苗的鲜重、干重、株高和根长;同时Spd能解除淹水胁迫产生的光抑制,使叶绿素含量及光合作用的相关指标有所提高;外源Spd处理可以提高胁迫下地毯草幼苗的抗氧化酶活性以及游离脯氨酸和可溶性蛋白的含量,减少体内活性氧的积聚,降低丙二醛的含量,通过稳定细胞膜结构,进而增强地毯草对淹水逆境的适应性。同时,通过相关性和主成分分析对不同处理的地毯草生理生化指标进行综合评价,证明外源Spd处理可以提高地毯草的耐涝性,本研究为降低淹水胁迫对地毯草的伤害以及抗涝栽培提供理论依据。

Reducing toxic effect of seed-soaked Cu fertilizer on germination of wheat

A laboratory incubation experiment (20℃) was conducted to find if the detrimental effects of seed-soaked Cu on wheat seedlings can be minimized by reducing time duration of seed in contact with Cu EDTA fertilizer solution. The 24 treatments in a 6 x 4 factorial arrangement included 6 rates/amounts of Cu (0, 15, 30, 60, 120 and 240 g Cu 100 kg-1 seed) and 4 seed-soaking time durations (0, 4, 8 and 16 h). The germination of wheat seed was 100% in the zero-Cu control treatments, irrespective of the duration of seed soaking time. However, seed germination decreased with increasing amount of fertilizer Cu in the seed-soaking solution, and the magnitude of reduction in seed germination due to Cu toxicity increased with increasing duration of seed-soaking time in the Cu fertilizer solution. For the seed-soaked treatments, the detrimental effect of Cu on germination was greatest with 16 h soaking, where only 13% - 18% of the seeds germinated with Cu applied at 15 to 30 g Cu 100 kg-1 seed. For the 4 and 8 h seed soaking treatments, germination of wheat seed ranged from 73% to 83% with 15 g Cu 100 kg-1 seed treatment and 42% to 62% with 30 g Cu 100 kg-1 seed. The findings suggest that the detrimental effect of Cu on germination of wheat seed soaked in Cu EDTA solution can be decreased by reducing duration of soaking time from 16 h to 4 or 8 h, but this needs further investigation using soil under growth chamber and/or field conditions in order to make valid recommendations for use of this new technology on a commercial scale.

外源亚精胺对苜蓿幼苗干旱缓解生理机制分析

为探讨外源亚精胺(Spd)提高苜蓿(Medicago sativa L.)抗旱的生理机制并为干旱缓解提供理论依据,本研究以‘龙苜807’为材料,采用营养液法培养苜蓿幼苗,以20%PEG-6000模拟干旱胁迫,研究不同浓度的Spd(0,0.3,0.6,0.9,1.2 mmol·L^(-1))对苜蓿幼苗叶片细胞膜透性、抗氧化酶活性、渗透调节物质及叶绿素的影响,利用隶属函数法综合评价外源Spd最佳缓解浓度。发现0.9 mmol·L^(-1) Spd使干旱胁迫下苜蓿幼苗叶片丙二醛(MDA)含量、H_(2)O_(2)含量和O_(2)^(-)·产生速率降低37.29%,46.84%和39.00%;超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性增大65.75%和60.21%;可溶性蛋白和脯氨酸含量增加93.27%和52.30%;叶绿素含量增加76.54%;0.6 mmol·L^(-1) Spd使干旱胁迫下苜蓿幼苗POD活性增加26.07%。1.2 mmol·L^(-1) Spd处理可溶性糖含量增加了77.62%。适宜Spd浓度可有效缓解干旱对苜蓿幼苗的伤害,以0.9 mmol·L^(-1) Spd为最佳。因此,外源Spd浓度可稳定苜蓿生物膜系统,增强抗氧化能力,维持细胞渗透平衡,有效缓解干旱对苜蓿幼苗的伤害。

三种多胺对隐秘小环藻生长及藻壳结构的影响

为了探究外源多胺的添加能否使硅藻壳的结构特征发生变化,本研究在实验室条件下比较了3种多胺(亚精胺、精胺和腐胺)不同浓度处理对隐秘小环藻(Cyclotella cryptica)生长、藻壳细微结构及主要物理特性的影响。研究显示,1000μmol/L精胺表现出致死效应,600、800及1000μmol/L的腐胺处理组中,细胞密度峰值分别在培养的第4、3、2天出现,显示出典型的“时间剂量效应”。其中100μmol/L亚精胺、1000μmol/L精胺以及200μmol/L腐胺处理组的硅质壳,在管状突出结构分布的位置和数量、壳孔区孔的排列、藻壳中心孔的分布、孔容孔径等方面发生较为明显的变化,如200μmol/L腐胺处理组藻壳总孔体积和比表面积仅为对照组的52.7%和53.6%。上述结果说明这3种多胺分子可以造成硅藻壳结构的改变。

NaCl胁迫下外源亚精胺对马铃薯幼苗生理特征的影响

【目的】研究NaCl胁迫下外源亚精胺(Spd)对马铃薯幼苗生理特征的影响,为新疆盐渍化区域马铃薯种植提供技术参考。【方法】以晋薯16号马铃薯幼苗为材料,采用不同浓度NaCl模拟盐胁迫处理,研究外源亚精胺Spd对马铃薯植株生长、叶片抗氧化酶活性、渗透调节物质含量的影响。【结果】盐胁迫抑制了马铃薯植株生长,使得超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)等酶促类抗氧化酶活性表现为低盐胁迫促进,高盐胁迫抑制;抗坏血酸(ASA)、谷胱甘肽(DSH)等非酶促类抗氧化酶含量均降低;脯氨酸、可溶性糖、氨基酸含量升高;外源亚精胺(Spd)通过提高叶绿素含量、根系活力,调节渗透调节物质含量,增强抗氧化酶活性等方式维持植物体的正常生理代谢功能。【结论】外源亚精胺(Spd)可提升马铃薯耐盐性,缓解盐胁迫对马铃薯植株的抑制作用,其中0.9 mmol/L Spd(S 3)浓度缓解效果最明显。

外源物质对甜瓜幼苗低温冷害的缓解效应

以2个甜瓜品种为试材,采用随机区组试验设计,研究了低温胁迫下不同浓度的外源水杨酸(SA)和亚精胺(Spd)对甜瓜幼苗生物学性状、抗氧化酶活性和光合同化功能的影响,外源水杨酸(SA)和亚精胺(Spd)对于甜瓜幼苗低温冷害的缓解效应,以期为增强甜瓜幼苗低温抗性提供参考依据。结果表明:低温胁迫下,随着外源亚精胺和水杨酸施用浓度的增加可以明显缓解低温对甜瓜幼苗的伤害,过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和可溶性蛋白质含量等抗氧化能力显著提升,增强抗低温能力,甜瓜幼苗光合同化功能明显增强。外源亚精胺和水杨酸对于缓解低温冷害的胁迫具有剂量效应,通过甜瓜幼苗生物学性状、抗氧化酶活性和光合同化功能综合分析可知,1.5 mmol·L^(-1)外源亚精胺和40.0 mmol·L^(-1)外源水杨酸施用浓度的甜瓜幼苗生长状态最佳。

亚精胺对渗透胁迫下甜瓜幼苗膜脂过氧化和抗氧化系统的影响

为探讨多胺提高作物抗渗透胁迫的生理机制,以甜瓜品种‘齐甜2号’为材料,采用营养液法培养甜瓜幼苗,以15%PEG-6000模拟渗透胁迫,研究1 mmol·L^(-1)亚精胺(Spd)对不同渗透胁迫时间下甜瓜幼苗的生长、活性氧代谢、抗氧化酶活性、渗透调节物质和非酶抗氧化剂的影响。结果表明:渗透胁迫后4 d,与胁迫处理相比,1mmol·L^(-1)Spd处理使甜瓜幼苗生物量提高11.34%,根系活力提高24.20%;叶片和根系H_(2)O_(2)含量、■产生速率、MDA含量和相对电解质渗透率降低,叶片中分别降低30.72%、29.99%、29.34%和14.62%,根中分别降低29.33%、25.31%、28.23%和20.34%。Spd诱导甜瓜叶片和根系中抗氧化酶活性增加,与胁迫处理相比,叶中SOD、POD、CAT和APX抗氧化酶活性分别提高25.54%、28.70%、27.72%和28.41%,根中分别提高23.35%、27.38%、25.06%和20.34%。与渗透胁迫处理相比,Spd处理在渗透胁迫后16 d甜瓜幼苗叶片脯氨酸、可溶性糖和可溶性蛋白的含量分别增加46.51%、49.72%和40.25%;渗透胁迫后16 d幼苗叶片ASA含量增加62.50%,渗透胁迫后12 d幼苗叶片GSH含量增加37.17%,ASA/DHA和GSH/GSSG分别提高74.46%、60.95%。说明在渗透胁迫下1 mmol·L^(-1)浓度Spd能够促进甜瓜幼苗生长,稳定生物膜系统,增强甜瓜幼苗抗氧化能力,有效缓解渗透胁迫对甜瓜幼苗伤害的作用。

亚精胺+赤霉素在低温下对化橘红种子萌发及幼苗生理指标的影响

以化橘红种子为材料,在低温下,研究亚精胺(Spd)+赤霉素(GA3)对化橘红种子萌发、幼苗根系的生长、根活力及生理指标的影响,以培育壮苗。设置亚精胺浓度为0(CK)、0.10、0.15、0.20、0.25 mmol/L,分别添加80 mg/L的GA3溶液浸种、培养,测定种子发芽率、发芽势,幼苗根长、苗长、根重、苗重、根长/苗长、根重/苗重、抗氧化酶活性、渗透调节物质及膜质过氧化物含量的变化。结果表明:在低温条件下,亚精胺+赤霉素对化橘红种子的萌发有协同促进作用,发芽率、发芽势和发芽指数明显提高;单一使用赤霉素时,幼苗根的生长受到抑制,添加亚精胺后能明显缓解,缓解程度与Spd的浓度呈正相关。0.20 mmol/L亚精胺+80 mg/L赤霉素处理的根长、根重、根长/苗长、根重/苗重和根活力最高,其幼苗根系的抗氧化酶(SOD、POD、CAT)活性显著增强,渗透调节物质脯氨酸和可溶性蛋白的含量有所提高,丙二醛(MDA)含量降低。亚精胺+赤霉素复配能促进化橘红种子萌发、根系的生长和根活力的提高;能缓解低温对化橘红幼苗根的损害,提高种苗的抗寒性。

外源亚精胺对枣树抗高温胁迫的调节机制

以‘早熟优’枣树为试材,设置常温喷蒸馏水(HckW)、高温喷蒸馏水(HW)、常温喷1 mmol·L^(-1)亚精胺(HckS)、高温喷1 mmol·L^(-1)亚精胺(HS)4个处理,研究了亚精胺对枣树抗高温胁迫的调节机制,以期为枣树优质栽培提供参考依据。结果表明:高温胁迫下的枣树生长指标增长速度显著低于常温对照和喷施亚精胺处理的枣树;高温处理的枣树光合色素含量显著降低,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性和丙二醛(MDA)、可溶性蛋白质、可溶性糖、脯氨酸(Pro)含量均显著升高;高温下喷施亚精胺(Spd)的枣树叶片内源脱落酸(ABA)含量先升后降;内源腐胺(Put)、精胺(Spm)、Spd含量上升明显,在处理7 d后基本达到最高值后开始下降。喷施亚精胺之后缓解了枣树对高温胁迫的响应。

亚精胺对弥漫大B细胞淋巴瘤细胞株增殖和凋亡的影响

目的探究亚精胺(spermidine)对弥漫大B细胞淋巴瘤(DLBCL)细胞株增殖和凋亡的影响。方法CCK-8法检测亚精胺对DLBCL细胞株生长的影响;流式细胞术检测亚精胺对DLBCL细胞株增殖和细胞周期的影响,并检测亚精胺对DLBCL细胞株、小鼠脾脏细胞及健康人外周血单个核细胞(PBMCs)凋亡的影响;Western blot检测亚精胺作用后DLBCL细胞株中细胞周期和凋亡相关蛋白表达的变化。结果CCK-8检测结果显示亚精胺显著抑制DLBCL细胞株的生长(P<0.001);流式染色检测结果表明亚精胺不影响DLBCL细胞株的增殖及细胞周期,但显著促进DLBCL细胞株的凋亡(P<0.001),亚精胺促进小鼠脾脏细胞凋亡(P<0.01),但该效应显著弱于其对DLBCL细胞株的促凋亡效应(P<0.001),亚精胺对PBMCs无显著促凋亡作用;Western blot结果表明亚精胺不影响DLBCL细胞株细胞周期蛋白CDK2和CDK4的表达水平,但促进A20细胞Caspase-9以及OCI-Ly3细胞Caspase-8的激活。结论亚精胺通过促进细胞凋亡进而抑制DLBCL细胞株的生长,而其对鼠脾脏细胞以及健康人PBMCs发挥的促凋亡效应较弱甚至无促凋亡作用,提示亚精胺可能具备在体内特异性地抑制DLBCL细胞株生长的潜力。

血清亚精胺作为绝经后女性髋部骨折潜在预测指标的初步研究

目的通过代谢组学确定与绝经后女性骨质疏松性骨折风险有关的替代指标,确定候选代谢物的预测价值。方法2018年12月~2021年8月收治的158例非创伤性髋部骨折的绝经后女性为分析对象(骨折组),另纳入197例非骨折绝经后女性为对照(非骨折组)。使用AbsoluteIDQTM p180试剂盒和靶向代谢组学法进行血清代谢物进行定量分析。采用单因素及多因素Logistic回归分析绝经后女性骨质疏松性骨折的影响因素,Spearman、Pearson分析其相关性。结果与非骨折组相比,骨折组只有血清精氨酸[(105.2±22.4)μmol/L vs.(96.3±23.5)μmol/L]、亮氨酸[(180.9±50.0)μmol/L vs.(156.7±39.5)μmol/L]和亚精胺[(1.03±0.67)μmol/L vs.(0.51±0.12)μmol/L]水平显著升高(P<0.05)。Logistic回归分析结果显示,在调整年龄、BMI、并发症、吸烟状况后,只有血清亚精胺浓度与髋部骨折风险显著相关(HR=1.35,95%CI=1.03~1.65,P=0.020)。经受试者工作特性曲线分析,血清亚精胺水平预测绝经后女性发生髋部骨折的曲线下面积为0.882(95%CI:0.847~0.916)。经Spearman分析,全髋T值与血清亚精胺水平呈显著负相关(r=-0.192,P<0.001)。血清亚精胺低水平亚组病人血清精胺和腐胺水平均较高水平亚组升高;经Pearson相关性分析,骨折组病人血清亚精胺水平与精胺(r=-0.237,P<0.001)和腐胺(r=-0.189,P=0.004)呈负相关。经单因素和多因素Logistic回归分析,血清亚精胺水平≥0.58μmol/L是绝经后女性发生髋部骨折风险增加的独立危险因素(P<0.001)。结论绝经后女性基线血清亚精胺水平升高与髋部骨折发生风险增加相关,对预测绝经后女性脆性骨折的发生有良好效能。

亚精胺通过抑制细胞凋亡、ROS生成及铁死亡减轻脂多糖诱导的小鼠心肌损伤

目的观察亚精胺(SPD)对脂多糖(LPS)诱导的脓毒症心肌损伤的保护作用及机制研究。方法在动物水平上,C57BL/6小鼠随机分为:空白对照组(Control)、LPS组(10mg/kg)、LPS+SPD组(5mmol/L),应用HE染色观察小鼠心肌组织形态变化,透射电镜观察心肌线粒体超微结构。在细胞水平上,根据处理方式及10和20μmol/LSPD,将大鼠H9c2心肌细胞随机分为:Control、LPS、LPS+SPD10、LPS+SPD20组,应用CCK-8试剂盒检测细胞活力,乳酸脱氢酶试剂盒检测细胞LDH水平、ELISA测定心肌细胞cTNI的变化,Western blot检测凋亡蛋白Bax、Bcl-2、Cleaved-caspase3表达水平及铁死亡相关蛋白SLC7A11、GPX4表达水平,应用荧光探针检测细胞活性氧ROS及Fe^(2+)水平,JC-1染色法检测细胞线粒体膜电位。结果小鼠心肌组织HE染色及透射电镜结果显示:Control组心肌及线粒体结构正常,LPS处理后,小鼠心肌组织结构紊乱、间隙变大,并且线粒体明显损伤,出现肿大、空泡化及坏死等现象,SPD处理可改善LPS导致的心肌及线粒体损伤。细胞水平上,与空白对照组相比,LPS组细胞活力明显下降(P<0.05),LDH、cTNI水平明显升高(P<0.05),细胞凋亡蛋白Bax、Cleaved-caspase3水平增加(P<0.05),Bcl-2蛋白表达水平下降(P<0.05),SLC7A11、GPX4蛋白的表达水平降低(P<0.05),细胞活性氧ROS及Fe^(2+)水平增加(P<0.05),线粒体膜电位下降;经SPD预处理后,H9c2细胞活力明显增加(P<0.05),LDH、cTNI水平降低(P<0.05),细胞凋亡蛋白Bax,Cleaved-caspase3的表达水平降低(P<0.05),Bcl-2蛋白表达水平增加(P<0.05),铁死亡相关蛋白SLC7A11、GPX4的表达水平增加(P<0.05),细胞活性氧ROS及Fe^(2+)水平降低(P<0.05),线粒体膜电位上升。结论SPD可减轻脓毒症心肌损伤,其机制与降低细胞凋亡、抑制细胞活性氧ROS产生、减轻铁死亡有关。