Mitochondrial Quality Control in the Heart: New Drug Targets for Cardiovascular Disease

Despite considerable efforts to prevent and treat cardiovascular disease (CVD), it has become the leading cause of death worldwide. Cardiac mitochondria are crucial cell organelles responsible for creating energy-rich ATP and mitochondrial dysfunction is the root cause for developing heart failure. Therefore, maintenance of mitochondrial quality control (MQC) is an essential process for cardiovascular homeostasis and cardiac health. In this review, we describe the major mechanisms of MQC system, such as mitochondrial unfolded protein response and mitophagy. Moreover, we describe the results of MQC failure in cardiac mitochondria. Furthermore, we discuss the prospects of 2 drug candidates, urolithin A and spermidine, for restoring mitochondrial homeostasis to treat CVD.

Evaluation of biogenic amines producing potential of bacteria associated with proteinous food

@#Aim: The aim of this study was to assay for the biogenic amine-producing capacity of bacteria isolated from proteinous food. Methodology and results: Previously characterized bacterial isolates (Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae) obtained from proteinous food samples (smoked fish and yoghurt) were subjected to proteolytic analysis using nutrient agar supplemented with 0.2 g/mL casein and decarboxylase activity using nutrient broth supplemented with 0.004 g/mL amino acids (histidine, tyrosine, asparagines, leucine and lysine). Isolates that expressed proteolytic and decarboxylase activities were screened for biogenic amine producing capacity using decarboxylase broth which was supplemented with an amino acid (tyrosine). Biogenic amines obtained in this research were classified into primary amine and secondary amine based on their qualitative characteristics. Confirmatory and quantitative analysis of biogenic amines produced was done using high-performance liquid chromatography. The confirmatory screening revealed the presence of methylamine, ethylamine, putrescine, cadaverine, histamine, spermidine, phernylethylamine, spermine, agmatine, tyramine, dopamine, tryptamine, norepinephrine and serotonin respectively. Total biogenic amines produced by S. aureus was 70.12 mg/kg, K. pneumoniae (62.58 mg/kg) and E. coli (56.57 mg/kg) respectively. Conclusion, significance and impact of study: Enzymatic decarboxylation of free amino acids and other metabolic processes by the test organisms (S. aureus, E. coli and K. pneumoniae) leads to production of biogenic amines which can be used as a quality indicator in food in terms of degree of spoilage, use of non-hygienic raw material and poor manufacturing environment. Thus, effect of biogenic amines obtained in this research would be determined by individual toxicological threshold which can be extremely variable from few mg/kg in sensitive person to several hundred mg/kg in healthy person. The concentrations of each biogenic amine quantified are within the limit but their toxic effects depend on the type of amine, the presence of modulating compounds and the efficiency of an individual’s detoxification mechanism.

Effect of different polyamines on some physiological traits, growth, and development of basil (Ocimum basilicum L.) in salt stress under hydroponic culture conditions

As basil occurs in the arid and semi-arid regions, the drought and salinity decrease the vegetative growth andleaf area. This research was carried out in Pakdasht private greenhouse to evaluate the effect of putrescine,spermine, and spermidine on quality and quantity of basil under conditions of salt stress. This research wasdone as a factorial experiment in a completely randomized block design with three replications. The treatmentsincluded application of putrescine, spermine, and spermidine at four levels (0, 50, 100, and 150 mg/l), salinitystress at four levels (0, 50, 100, and 150 mM), and control treatment. The results showed that the interactioneffects between polyamines, salinity, and concentration on plant height, fresh/dry shoot weight, fresh/dryweight of root, fresh/dry leaf weight, leaf chlorophyll content, catalase, peroxidase and guaiacol peroxidaseantioxidant enzymes, the ratio of K/Na ratio, ion leakage, and proline were statistically significant at 1% level.Interaction and simultaneous exposure of 150 mg/l spermidine and low salinity had a positive effect on all thestudied plant traits. In addition, the results showed that the concentration of 150 mM sodium chloride solutionreduced the mentioned traits. However, spermidine improved this condition, and symptoms of stress anddamages were less observed in spermidine-treated plants. Therefore, it can be used to withstand the oxidativestress of plants.

Molecular mechanism underlying the inhibitory effect of spermine oxidase inhibitor SI-4650 on proliferation of a human malignant melanoma cell line A375 / 中华皮肤科杂志

Objective@#To evaluate the effect of spermine oxidase (SMO) inhibitor SI-4650 on the proliferation of a human malignant melanoma cell line A375, and to explore its molecular mechanism.@*Methods@#Some cultured A375 cells were divided into 6 groups to be treated with SI-4650 at concentrations of 0, 10, 20, 40, 80 and 160 μmol/L respectively for 24, 48 and 72 hours, and methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate changes in cellular proliferative activity. According to the cellular proliferative activity, 3 concentrations (0, 40, 80 μmol/L) were screened out. Some A375 cells were divided into 3 groups to be treated with 0 (control group) , 40 and 80 μmol/L SI-4650 for 48 hours. Chemiluminescence assay was conducted to detect the SMO activity in A375 cells, high-performance liquid chromatography (HPLC) analysis to determine the polyamine content in A375 cells, flow cytometry to analyze the cell cycle and detect the apoptosis, and Western blot analysis to determine the protein expression of apoptotic marker proteins Bax and c-PARP, inhibitor of apoptosis protein Bcl-2, and autophagy marker proteins Beclin-1 and LC3-Ⅱ. Statistical analysis was carried out by using one-way analysis of variance for comparison of means among several groups, and by using Student-Newman-Keuls (SNK) -q test for multiple comparisons.@*Results@#MTT assay showed that there was a significant difference in the proliferative activity of A375 cells after the treatment with different concentrations of SI-4650 for different durations (F = 977.23, 5.16 respectively, both P < 0.001) . Significant differences were observed in the SMO activity in A375 cells (F = 242.58, P < 0.001) , spermine and the total polyamine content (F = 338.02, 2 931.07 respectively, both P < 0.001) , proportion of S-phase cells (F = 31.66, P < 0.001) , proportion of apoptotic cells (F = 100.68, P < 0.001) , expression of apoptosis-related proteins Bax, c-PARP and Bcl-2 (F = 35.51, 730.11, 27.54 respectively, all P < 0.001) , and expression of autophagy marker proteins Beclin-1 and LC3-Ⅱ (F = 35.87, 425.04 respectively, P < 0.001) among the control group, 40- and 80-μmol/L SI-4650 groups. Compared with the control group, the 40- and 80-μmol/L SI-4650 groups showed significantly lower SMO activity (luminous intensity: 61 432.85 ± 2 620.92, 43 337.35 ± 1 221.25 respectively, both P < 0.05) , lower spermine (1.97 ± 0.007, 1.88 ± 0.006 respectively, both P < 0.05) and total polyamine content (3.18 ± 0.03, 2.81 ± 0.01 respectively, both P < 0.05) , higher proportions of S-phase cells (27.61% ± 2.05%, 31.58% ± 1.45% respectively, both P < 0.05) and apoptotic cells (27.61% ± 2.05%, 31.58% ± 1.45% respectively, both P < 0.05) , higher expression of apoptotic marker proteins Bax (0.83 ± 0.12, 1.18 ± 0.16 respectively, both P < 0.05) and c-PARP (0.32 ± 0.002, 0.79 ± 0.035 respectively, both P < 0.05) and autophagy marker proteins Beclin-1 (1.00 ± 0.007, 1.14 ± 0.003 respectively, both P < 0.05) and LC3-Ⅱ (0.31 ± 0.001, 0.98 ± 0.003 respectively, both P < 0.05) , and lower expression of inhibitor of apoptosis protein Bcl-2 (0.65 ± 0.09, 0.12 ± 0.002 respectively, both P < 0.05) .@*Conclusion@#SI-4650 can inhibit the proliferation of A375 cells, likely by interfering with polyamine metabolism and inducing cell cycle arrest, apoptosis and autophagy.

Molecular mechanism underlying the inhibitory effect of spermine oxidase inhibitor SI-4650 on proliferation of a human malignant melanoma cell line A375 / 中华皮肤科杂志

Objective To evaluate the effect of spermine oxidase(SMO)inhibitor SI-4650 on the proliferation of a human malignant melanoma cell line A375, and to explore its molecular mechanism. Methods Some cultured A375 cells were divided into 6 groups to be treated with SI- 4650 at concentrations of 0, 10, 20, 40, 80 and 160 μmol/L respectively for 24, 48 and 72 hours, and methyl thiazolyl tetrazolium(MTT)assay was performed to evaluate changes in cellular proliferative activity. According to the cellular proliferative activity, 3 concentrations (0, 40, 80 μmol/L) were screened out. Some A375 cells were divided into 3 groups to be treated with 0(control group), 40 and 80μmol/L SI-4650 for 48 hours. Chemiluminescence assay was conducted to detect the SMO activity in A375 cells, high-performance liquid chromatography(HPLC)analysis to determine the polyamine content in A375 cells,flow cytometry to analyze the cell cycle and detect the apoptosis, and Western blot analysis to determine the protein expression of apoptotic marker proteins Bax and c-PARP, inhibitor of apoptosis protein Bcl-2, and autophagy marker proteins Beclin-1 and LC3-Ⅱ. Statistical analysis was carried out by using one-way analysis of variance for comparison of means among several groups, and by using Student-Newman-Keuls (SNK)-q test for multiple comparisons. Results MTT assay showed that there was a significant difference in the proliferative activity of A375 cells after the treatment with different concentrations of SI-4650 for different durations(F=977.23, 5.16 respectively, both P<0.001). Significant differences were observed in the SMO activity in A375 cells(F=242.58, P<0.001), spermine and the total polyamine content(F=338.02, 2931.07 respectively, both P < 0.001), proportion of S-phase cells (F = 31.66, P < 0.001), proportion of apoptotic cells(F=100.68, P<0.001), expression of apoptosis-related proteins Bax, c-PARP and Bcl-2(F = 35.51, 730.11, 27.54 respectively, all P < 0.001), and expression of autophagy marker proteins Beclin-1 and LC3-Ⅱ(F = 35.87, 425.04 respectively, P < 0.001)among the control group, 40-and 80-μmol/L SI-4650 groups. Compared with the control group, the 40-and 80-μmol/L SI-4650 groups showed significantly lower SMO activity(luminous intensity:61432.85 ± 2620.92, 43337.35 ± 1221.25 respectively, both P<0.05), lower spermine(1.97 ± 0.007, 1.88 ± 0.006 respectively, both P<0.05)and total polyamine content (3.18 ± 0.03, 2.81 ± 0.01 respectively, both P < 0.05), higher proportions of S-phase cells (27.61％ ± 2.05％, 31.58％ ± 1.45％ respectively, both P < 0.05) and apoptotic cells (27.61％ ± 2.05％, 31.58％ ± 1.45％ respectively, both P < 0.05), higher expression of apoptotic marker proteins Bax(0.83 ± 0.12, 1.18 ± 0.16 respectively, both P < 0.05)and c-PARP(0.32 ± 0.002, 0.79 ± 0.035 respectively, both P < 0.05)and autophagy marker proteins Beclin-1(1.00 ± 0.007, 1.14 ± 0.003 respectively, both P < 0.05)and LC3-Ⅱ(0.31 ± 0.001, 0.98 ± 0.003 respectively, both P < 0.05), and lower expression of inhibitor of apoptosis protein Bcl-2(0.65 ± 0.09, 0.12 ± 0.002 respectively, both P<0.05). Conclusion SI-4650 can inhibit the proliferation of A375 cells, likely by interfering with polyamine metabolism and inducing cell cycle arrest, apoptosis and autophagy.

Application of plant medicine containing spermine in pingyangmycin fermentation / 中草药

Objective: Screening a plant medicine containing spermidine to promote the fermentation of pingyangmycin (PYM). Methods: Based on the screening method of carbon and nitrogen sources in biological fermentation, the plant medicine with the best promotion effect on PYM was screened out by HPLC method in Lycium ruthenicum, Lycium barbarum, Lycium barbarum bud, Carthamus tinctorius, and Coicis Semen. And the best adding time, amount and frequency were also screened out. Results: The results showed that Lycium barbarum bud had the best effect on PYM fermentation, and the initial adding time was 24 h, the adding interval was 24 h, and the adding frequency was three times. The shaking bottle fermentation level was 21.3 μg/mL when the addition amount was 7 g/L/per batch, and the 25 L tank fermentation level was 37.5 μg/mL when the addition amount was 18 g/L/per batch, which increased by 23.8% and 118.0%, respectively. Compared with the addition of spermidine, the yield was increased by 45.3%. Conclusion: Most plant drugs containing spermidine can promote the fermentation of pingyangmycin, and the selection of Lycium barbarum bud as raw materials for pingyangmycin fermentation meets the production requirements in terms of cost, yield and environmental protection.

Changes of polyamine metabolism and autophagy in aging heart and effect of exogenous spermidine on autophagy in aged rat heart / 中国药理学通报

Aim To discuss the changes of polyamine metabolism and autophagy in aging rat heart and the effect of exogenous spermidine on autophay in aged rat heart. Methods Western blot assay was used to detect the expressions of ODC and SSAT-rate-limiting enzyme of polyamine anabolism and catabolism as well as the expression of autophagy-relevant protein LC3?/? and p62 in cardiac tissues from male Wistar rats aged 3, 6, 12 and 24 months, and the expressions of p16, LC3?/?, ATG5 and ATG7 protein were detected in cardiac tissues in rats aged 3 months, 24 months and 24 months with spermidine administrtion, respectively. The myocardial autophagosome formation was observed by transmission electron microscope. In addition, cell cross-sectional area, cell apoptosis rate and generation of ROS were evaluated. Results With heart aging in rats, ODC expression and LC3?/? ratio were degraded, and SSAT and p62 protein expression upgraded. In rats aged 24 months, myocardium showed increased p16 expression, cell cross-sectional area, cell apoptosis and ROS generation, while cell autophagosome formation decreased, p62 expression increased, the expression of LC3?/?, ATG5 and ATG7 all declined. Spermidine intervention obviously inhibited myocardial changes induced by aging, showing decrease in cell cross-sectional area, apoptosis, ROS generation and p62 expression, and increase in LC3?/?, ATG5 and ATG7 expression. Conclusions With heart aging in rats, polyamine anabolism is degraded, catabolism is upgraded, and cell autophagy declined. Exogenous spermidine might delay aging through inducing autophagy of cardiomyocytes.

The application of polyamines and self-incompatibility control substance on yield indices and qualitative traits of apple cv ‘Red Delicious’ / A aplicação de poliaminas e substância de controle de auto-incompatibilidade em índices de produção e características qualitativas da maçã 'Red Delicious'

Among the main problems of some temperate fruit species, such as the apple tree (Malus domestica), are the poor set of fruits and low production. Polyamines and Self-Incompatibility Control Substances (SICS), involving mineral nutrients such as manganese and boron, are the major chemical compounds used to reduce these problems. The aim of this study was to use popular polyamines putrescine (Put) at 0.1, 0.25 mM, spermine (Spm) and spermidine (Spd) both at 0.05, 0.25 mM and SICS at 1, 2 mg L-1, alone or with cotton coverage bags and control to show the effects of these chemical compounds on yield indices and qualitative traits of apple (Malus domestica) cv ‘Red Delicious’. Results showed that Spd (0.25 mM) and SICS (1 mg L-1) had higher effect on yield per weight and per fruit number, final fruit set and ISI, but Spd (0.25 mM) decreased final drop. Put (0.1 mM + ccb), Spd (0.25 mM) and SICS (2 mg L-1 + ccb) were the most suitable treatments in order to increase the qualitative characteristics.

Entre os principais problemas de algumas espécies frutíferas de clima temperado, como a macieira (Malus domestica), está o fraco conjunto de frutos e a baixa produção. As Poliaminas e Substancias de Controle de Auto-Incompatibilidade (self-incompatibility control substances-SICS) (envolvendo nutrientes minerais tais como manganês e boro) são os principais compostos químicos usados para reduzir esses problemas. O objetivo deste trabalho foi empregar a poliamina putrescina (Put) em 0,1, 0,25 mM, espermina (Spm) e espermidina (Spd) ambas em 0,05, 0,25 mM e SICS em 1,2 mg L-1, sozinhos ou com sacos cobertos de algodão, para demonstrar o efeito destes elementos químicos nos índices de produção e características qualitativas da maça (Malus domestica) ‘Red Delicious’. Resultados mostraram que a espermidina (0.25 mM) e SICS (1 mg L-1) tiveram um efeito maior na produção por peso e pelo número de frutos, o conjunto final de frutos e ISI, mas a espermidina (0.25 mM) caiu na produção final. Put (0.1 mM + sca), Spd (0.25 mM) e SICS (2 mg L-1 + sca) foram os tratamentos mais adequados para aumentar as características qualitativas.

Spermidine Protects against Oxidative Stress in Inflammation Models Using Macrophages and Zebrafish

Spermidine is a naturally occurring polyamine compound that has recently emerged with anti-aging properties and suppresses inflammation and oxidation. However, its mechanisms of action on anti-inflammatory and antioxidant effects have not been fully elucidated. In this study, the potential of spermidine for reducing pro-inflammatory and oxidative effects in lipopolysaccharide (LPS)-stimulated macrophages and zebrafish was explored. Our data indicate that spermidine significantly inhibited the production of pro-inflammatory mediators such as nitric oxide (NO) and prostaglandin E2 (PGE2), and cytokines including tumor necrosis factor-α and interleukin-1β in RAW 264.7 macrophages without any significant cytotoxicity. The protective effects of spermidine accompanied by a marked suppression in their regulatory gene expression at the transcription levels. Spermidine also attenuated the nuclear translocation of NF-κB p65 subunit and reduced LPS-induced intracellular accumulation of reactive oxygen species (ROS) in RAW 264.7 macrophages. Moreover, spermidine prevented the LPS-induced NO production and ROS accumulation in zebrafish larvae and was found to be associated with a diminished recruitment of neutrophils and macrophages. Although more work is needed to fully understand the critical role of spermidine on the inhibition of inflammation-associated migration of immune cells, our findings clearly demonstrate that spermidine may be a potential therapeutic intervention for the treatment of inflammatory and oxidative disorders.

Exogenous spermidine ameliorates tubular necrosis during cisplatin nephrotoxicity / 대한해부학회지

The hallmark of cisplatin-induced acute kidney injury is the necrotic cell death in the kidney proximal tubules. However, an effective approach to limit cisplatin nephrotoxicity remains unknown. Spermidine is a polyamine that protects against oxidative stress and necrosis in aged yeasts, and the present study found that exogenous spermidine markedly attenuated tubular necrosis and kidney dysfunction, but not apoptosis, during cisplatin nephrotoxicity. In addition, exogenous spermidine potently inhibited oxidative/nitrative DNA damage, poly(ADP-ribose) polymerase 1 (PARP1) activation and ATP depletion after cisplatin injection. Conversely, inhibition of ornithine decarboxylase (ODC) via siRNA transfection in vivo significantly increased DNA damage, PARP1 activation and ATP depletion, resulting in acceleration of tubular necrosis and kidney dysfunction. Finally, exogenous spermidine removed severe cisplatin injury induced by ODC inhibition. In conclusion, these data suggest that spermidine protects kidneys against cisplatin injury through DNA damage and tubular necrosis, and this finding provides a novel target to prevent acute kidney injury including nephrotoxicity.

Effects of Modified Danshen Decoction on SSAT Activity of Rats with Myocardial Ischemia/Reperfusion Injury / 中国中医药信息杂志

Objective To observe the effects of modifiedDanshen Decoction on spermidine/spermine acetyltransferase (SSAT) /polyamine pathways of SD rats with IRI; To investigate its protective mechanism. Methods The model of IRI was established by ligating left anterior descending coronary artery for 30 min followed by reperfusion for 90 min. The SD rats were randomly divided into the control group, sham-operation group, model group and modifiedDanshen Decoction group, with 10 rats in each group. The myocardial infarction size was measured by using TTC staining. The contents of SSAT were measured by ELISA. The SSAT mRNA and SSAT protein expression level were detected with real-time fluorescent quantitative PCR method and Western blot, respectively. The contents of polyamines (putrescine, spermidine, spermine) in cardiac tissue were detected by HPLC. Results Compared with sham-operation group, the myocardial infarction size, the SSAT content, the SSAT mRNA and SSAT protein expression levels of model group increased significantly, the contents of polyamines decreased significantly, with statistical significance (P<0.01); Compared with model group, the myocardial infarction size of modifiedDanshen Decoction group was significantly reduced, while the SSAT content and SSAT mRNA and protein expression level decreased significantly, the contents of polyamines increased, with statistical significance (P<0.05, P<0.01).ConclusionModifiedDanshen Decoction can adjust the SSAT polyamine pathways and increase polyamine content in cardiomyocytes, and thus play a role of protection of myocardial ischemia-reperfusion injury.

Spermidine is protective against kidney ischemia and reperfusion injury through inhibiting DNA nitration and PARP1 activation / 대한해부학회지

Kidney ischemia and reperfusion injury (IRI) is associated with a high mortality rate, which is attributed to tubular oxidative and nitrative stresses; however, an effective approach to limit IRI remains elusive. Spermidine, a naturally occurring polyamine, protects yeast cells against aging through the inhibition of oxidative stress and necrosis. In the present study, spermidine supplementation markedly attenuated histological damage and kidney dysfunction during IRI. In addition, exogenous spermidine potently inhibited poly(ADP-ribose) polymerase 1 (PARP1) activation and DNA nitrative/oxidative stress following IRI. Conversely, inhibition of ornithine decarboxylase (ODC) via siRNA transfection in vivo significantly enhanced DNA nitration, PARP1 activation, and functional damage during IRI. Finally, in ODC knockdown kidneys, PARP1 inhibition attenuated histological and functional damage induced by IRI, but not DNA nitrative stress. In conclusion, these data suggest that spermidine protects kidneys against IRI through blocking DNA nitration and PARP1 activation and this finding provides a novel target for prevention of acute kidney injury including IRI.

A microdroplet cell culture based high frequency somatic embryogenesis system for pigeonpea, Cajanus cajan (L.) Millsp.

A protocol for high frequency production of somatic embryos was worked out in pigeonpea, Cajanus cajan (L.) Millsp. The protocol involved sequential employment of embryogenic callus cultures, low density cell suspension cultures and a novel microdroplet cell culture system. The microdroplet cell cultures involved culture of a single cell in 10 µl of Murashige and Skoog’s medium supplemented with phytohormones, growth factors and phospholipid precursors. By employing the microdroplet cell cultures, single cells in isolation were grown into cell clones which developed somatic embryos. Further, 2,4-dichlorophenoxyacetic acid, kinetin, polyethylene glycol, putrescine, spermine, spermidine, choline chloride, ethanolamine and LiCl were supplemented to the low density cell suspension cultures and microdroplet cell cultures to screen for their cell division and somatic embryogenesis activity. Incubation of callus or the inoculum employed for low density cell suspension cultures and microdroplet cell cultures with polyethylene glycol was found critical for induction of somatic embryogenesis. Somatic embryogenesis at a frequency of 1.19, 3.16 and 6.51 per 106 cells was achieved in the callus, low density cell suspension cultures and microdroplet cell cultures, respectively. Advantages of employing microdroplet cell cultures for high frequency production of somatic embryos and its application in genetic transformation protocols are discussed.

Contenido de poiiaminas libres en palmas afectaas por pudricion del cogollo enn las zonas central y occidental de Cloombia / Free olyamine coontent on oil palms aected by bud rot in the Colombiian central and western palm regions

La pudrición del cogollo (PC) es la principal enfermedad de la palma en Colombia. En las zonas palmeras Central (ZC) y Oriental (ZOR), las palmas enfermas pueden recuperarse naturalmente. En la Zona Occidental (ZOCC) el proceso de recuperación no es evidente. La recuperación de palmas está ligada a gran actividad meristemática que podría involucrar la acción de metabolitos como las poliaminas (PA). Este trabajo muestra la relación entre el contenido de poliaminas en el meristemo y la capacidad de recuperación de palmas con PC, en dos zonas agroclimáticas diferentes. Poliaminas extraídas del meristemo de palmas en ZC y ZOCC, fueron analizadas por HPLC. En ZC, donde existe recuperación espontánea, los niveles más altos de PA se presentan en palmas sanas y en recuperación y a medida que avanza la enfermedad la concentración desciende hasta un mínimo en el estado de PC inicial. Luego la concentración de PA aumenta hasta el estado de Buena Recuperación donde los valores de poliaminas son más altos que los de palmas sanas. En la ZOCC , el contenido de PA aumenta con la enfermedad llegando al máximo en plantas sin recuperación y el mínimo en plantas sanas. Las diferencias entre zonas pueden explicarse por los diferentes roles de las poliaminas en plantas. En la ZC la cantidad elevada de PA en palmas sanas o en recuperación funcionaría en la inducción de actividad meristemática, para la recuperación espontánea. En la ZOCC el aumento en el contenido de PA con la enfermedad puede estar relacionado con la producción de especies reactivas de oxigeno para defensa secundaria contra patógenos. A diferencia de lo observado en ZC , las plantas en ZOCC no pueden producir estructuras sanas que no sean re infectadas, por lo tanto los elevados contenidos de PA no están relacionados con la promoción de la actividad meristemática.

Bud Rot complex (BR) is the major disease of oil palm in Colombia . In the Central (ZC) and Eastern (ZE) oil palm regions, palms affected by BR are able to naturally recover. In the Western Region (ZW) the recovery process is not evident. Recovery of the palms is linked to high meristem activity, which could involve the promoting action of plant growth regulators such as polyamines (PA). This study shows the relationship between polyamine content and the capacity of palms to recover from BR in two regions with different agroclimatic conditions. Polyamines extracted from palms planted on ZC and ZW were analyzed by HPLC. On ZC where spontaneous recovery is present, the highest values were measured on healthy and recovery palms and with the progression of the disease, PA concentration decreased reaching a minimum point in the initial BR stage. From this point, PA concentration gradually increased until the Good Recovery stage in which PA values where higher than those found on healthy palms. In ZW , PA content increased with the disease, reaching the highest value in the affected palms without recovery, with the lowest values measured on healthy palms. The differences between regions might be related to the different roles polyamines play on plants. In ZC the increased amount of PA in healthy palms or in palms under recovery could have a major role in meristem activity induction, required for the spontaneous recovery. In the ZW, the increased of PA content with the disease could be related to the production of reactive oxygen species as a plant secondary defense mechanism due to the impossibility for the plants to, through the increment on meristem activity as the observed in the Central region, produce healthy structures which are not re-infected.

Polyamine patterns in haploid and diploid tobacco tissues and in vitro cultures

The aim of this work was to determine PAs levels in pith tissues and callus cultures from haploid and diploid tobacco plants, explanted from the apical and basal regions of the stem. These explants were cultured in an RM-64 medium supplied with IAA and kinetin, under light or in the dark, during successive subcultures. PAs levels followed a basipetal decrease in diploid and an increase in haploid, pith tissues. A similar pattern of total PAs (free + conjugated) was observed for the callus of diploid and haploid plants maintained in the light, and for the haploid callus in the dark, whereas the diploid callus in the dark showed a constant increase in total PAs levels until the end of culture. The PA increase in the diploid callus in the dark was related to free Put levels increase. The ploidy status of the plants could express different PA gradients together with the plant pith and in vitro callus cultures.

O objetivo deste trabalho foi determinar os níveis de PAs em tecidos de medula e cultura de calos de plantas haplóides e diplóides de tabaco, obtidas da região apical e basal do caule. Estes explantes foram cultivados em meio RM-64 suplementado com AIA e cinetina, na luz e no escuro, durante vários subcultivos. Nos tecidos medulares, os níveis de PAs apresentam um decréscimo basípeto em diplóides e um aumento em haplóides.Um padrão similar nos níveis de PAs totais (livres+ conjugadas) foi observado em calos haplóides e diplóides mantidos na luz, e haplóides no escuro, enquanto os diplóides cultivados no escuro mostraram um aumento constante até o final do cultivo. O aumento no conteúdo de PAs nos calos diplóides no escuro, foi devido ao aumento do conteúdo de Put livre. Foi observado que a ploidia da planta pode expressar diferentes gradientes de PA ao longo do tecido medular e nas culturas de calos in vitro.

Reguladores vegetais e teores endógenos de poliaminas durante o desenvolvimento de taro cultivado in vitro / Plant growth regulators in polyamines endogenous levels during the development of taro cultivated in vitro

Neste trabalho foi investigada a assepsia para obtenção de explantes oriundos de tubérculos e a ação das poliaminas espermidina e espermina exógenas associadas aos reguladores vegetais AIA e BA no desenvolvimento, na tuberização in vitro e nos níveis endógenos de putrescina (Put), espermidina (Spd) e espermina (Spm) de taro (Colocasia esculenta). Plantas crescidas em meio contendo espermidina e espermina mostraram tuberização e a associação dessas poliaminas com AIA e BA induziu aumento do número de brotações. Para o estímulo da rizogênese, não foi necessário o uso de reguladores vegetais. Altos teores de putrescina foram encontrados durante a emissão de brotações, enquanto que altos teores de espermidina foram observados durante a formação de rizomas in vitro.

The present research investigated the asepsis for attainment of explants deriving of tubers and the polyamines espermidine and espermine exogenous effects associated with the plant growth regulators NAA and BA on the development and tuberization in vitro and the endogenous levels of putrescine (Put), spermidine (Spd) and spermine (Spm) of taro (Colocasia esculenta). Plants grown in the medium with spermidine and spermine showed tuberization and the association of these polyamines with NAA and BA increases number of shoots. Plant growth regulators were not necessary for root initiation. High levels of endogenous Put were found during the shoot emission, while high levels Spd were observed during in vitro root formation.

Papel de las poliaminas en la alimentación: Importancia de las poliaminas en la alimentación infantil

Durante la década de los 90 del siglo pasado comenzaron los primeros estudios que señalaban a las poliaminas como importantes factores de crecimiento de la leche materna. Sin embargo, todavía se desconoce mucho sobre el papel que desempeñan en la alimentación infantil y cual sería la ingesta recomendada para este grupo poblacional. En los últimos años va siendo cada vez mayor la atención que muestra la comunidad científica internacional hacia las poliaminas, debido no sólo al importante papel que desempeñan en el metabolismo celular, sino por su posible participación en diversas patologías y durante el desarrollo del organismo. Sería recomendable, teniendo en cuenta que el contenido en poliaminas de las fórmulas infantiles es unas 10 veces menor al de la leche materna, profundizar más en este campo, con el fin de garantizar una correcta alimentación durante la etapa de lactancia.

Role of polyamines in diet. Importance of polyamines in infant nutrition. The first studies indicating polyamines as important growth factors in breast milk began during the nineties of last century. Nevertheless, it is still not well known the role they play in infant nutrition or what the recommended intake would be for this population group. In recent years, there has been increased attention of the international scientific community towards polyamines, not only due to the important role they play in the cellular metabolism, but also to their possible implication in some diseases and during the development of the human organism. Bearing in mind that the content in polyamines of the infant formula is around tenfold less than in breast milk, it would be recommended to gain insight into this theme in order to guarantee correct nutrition during lactation.

Relaxant Effect of Spermidine on Acethylcholine and High K+-induced Gastric Contractions of Guinea-Pig

In our previous study, we found that spermine and putrescine inhibited spontaneous and acetylcholine (ACh)-induced contractions of guinea-pig stomach via inhibition of L-type voltage- dependent calcium current (VDCCL). In this study, we also studied the effect of spermidine on mechanical contractions and calcium channel current (IBa), and then compared its effects to those by spermine and putrescine. Spermidine inhibited spontaneous contraction of the gastric smooth muscle in a concentration-dependent manner (IC50=1.1+/-0.11 mM). Relationship between inhibition of contraction and calcium current by spermidine was studied using 50 mM high K+-induced contraction: Spermidine (5 mM) significantly reduced high K+(50 mM)-induced contraction to 37+/-4.7% of the control (p<0.05), and inhibitory effect of spermidine on IBa was also observed at a wide range of test potential in current/voltage (I/V) relationship. Pre- and post-application of spermidine (5 mM) also significantly inhibited carbachol (CCh) and ACh-induced initial and phasic contractions. Finally, caffeine (10 mM)-induced contraction which is activated by Ca2+-induced Ca2+release (CICR),` was also inhibited by pretreatment of spermidine (5 mM). These findings suggest that spermidine inhibits spontaneous and CCh-induced contraction via inhibition of VDCCL and Ca2+releasing mechanism in guinea-pig stomach.

Effects of Polyamines on Contractility of Guinea-Pig Gastric Smooth Muscle

This study was designed to investigate the effects of polyamines on mechanical contraction and voltage-dependent calcium current (VDCC) of guinea-pig gastric smooth muscle. Mechanical contraction and calcium channel current (I(Ba)) were recorded by isometric tension recording and whole-cell patch clamp technique. Spermine, spermidine and putrescine inhibited spontaneous contraction of the gastric smooth muscle in a concentration-dependent manner. Spermine (2 mM) reduced high K+ (50 mM)-induced contraction to 16+/-6.4% of the control (n=9), and significantly inhibited I(Ba) in a reversible manner (p<0.05; IC50=0.8 mM). Pre- and post-treatment of tissue with spermine (2-5 mM, n=10) also inhibited acetylcholine (10 micrometer)-induced phasic contraction to 5+/-6.4% of the control. Inhibitory effect of spermine on I(Ba) was observed at a wide range of test potentials of current/voltage (I/V) relationship (p<0.05), and steady-state activation of I(Ba) was shifted to the right by spermine (p<0.05). Spermidine and putrescine (1 mM each) also inhibited I(Ba) to 51+/-5.7% and 81+/-5.3% of the control, respectively. And putrescine (1 mM) inhibited I(Ba) at whole tested potentials (p<0.05) without significant change of kinetics (p<0.05). Finally, 5 mM putrescine also inhibited high K+ -induced contraction to 53+/-7.1% of the control (n=4). These findings suggest that polyamines inhibit contractions of guinea-pig gastric smooth muscle via inhibition of VDCC.

Control of ornithine decarboxylase activity in jute seeds by antizyme.

The control of ornithine decarboxylase activity by antizyme was studied during early germination of jute seeds (Corchorus olitorius). When 2 mM of putrescine and spermidine were applied to the germinating medium, the enzyme activity was markedly inhibited (1.7-fold) during 16 h imbibition. This inhibition could be attributed to the formation of an inhibitory protein termed antizyme. The antizyme was partially purified from jute and barley seedlings. The activity of jute ornithine decarboxylase antizyme was weaker than that of barley.