Profiling neuroprotective potential of trehalose in animal models of neurodegenerative diseases:a systematic review

Trehalose,a unique nonreducing crystalline disaccharide,is a potential disease-modifying treatment for neurodegenerative diseases associated with protein misfolding and aggregation due to aging,intrinsic mutations,or autophagy dysregulation.This systematic review summarizes the effects of trehalose on its underlying mechanisms in animal models of selected neurodegenerative disorders(tau pathology,synucleinopathy,polyglutamine tract,and motor neuron diseases).All animal studies on neurodegenerative diseases treated with trehalose published in Medline(accessed via EBSCOhost)and Scopus were considered.Of the 2259 studies screened,29 met the eligibility criteria.According to the SYstematic Review Center for Laboratory Animal Experiment(SYRCLE)risk of bias tool,we reported 22 out of 29 studies with a high risk of bias.The present findings support the purported role of trehalose in autophagic flux and protein refolding.This review identified several other lesser-known pathways,including modifying amyloid precursor protein processing,inhibition of reactive gliosis,the integrity of the blood-brain barrier,activation of growth factors,upregulation of the downstream antioxidant signaling pathway,and protection against mitochondrial defects.The absence of adverse events and improvements in the outcome parameters were observed in some studies,which supports the transition to human clinical trials.It is possible to conclude that trehalose exerts its neuroprotective effects through both direct and indirect pathways.However,heterogeneous methodologies and outcome measures across the studies rendered it impossible to derive a definitive conclusion.Translational studies on trehalose would need to clarify three important questions:1)bioavailability with oral administration,2)optimal time window to confer neuroprotective benefits,and 3)optimal dosage to confer neuroprotection.

Biological Characteristics of Trehalose and Its Protective Effect on Food Fermentation Starters during Lyophilization

This paper reviewed the unique biological function of trehalose and its mechanism of stabilizing biological macromolecules and the research progress in the protective effect of trehalose on lactic acid bacteria fermentation starters during lyophilization in food production.The application of trehalose in food industry was prospected.

Advances in Trehalose Biosynthesis Pathways and Application of Molecular Biology Technique

This paper aims to provide better guidance for construction of trehalose-producing recombinant strains to further improve the yield of trehalose. The research progress on trehalose biosynthesis pathways and the application of molecular biology technique in trehalose study in recent 30 years, especially the last 10 years are reviewed. Results show that there are 5 pathways of trehalose synthesis. Although enzymes and genes of trehalose synthesis have been isolated and genetic engineering strains have increased gradually, the improvement of trehalose yield is still inadequate because most recombinant strains are limited to study the physicochemical properties of single enzyme. With the development of modern biological technology, especially the rapid development of DNA recombinant technology, metagenomics and synthetic biology, high expression of heterologous trehalose in recombinant strains would become a hot research topic in the future.

Immobilization of Trehalose Synthase on Mesoporous Molecular Sieve

[ Objective] This study aimed to explore the immobitizatian of trehalose synthase on mesoporous molecular sieves. [ Method] With trehalose synthase produced by genetically engineered bacteria as experimental material, rnesoporous molecular sieve MCM-41 was used as a carrier for immobilization of trehalase syn- thase. Properties of trehalose synthase before and after immobilization were compared. [ Result ] Trehalose synthase could be immohihzed on mesoporous molecular sieve MCM-41 by using physical adsorption method. Immobilization of trehalose synthase achieved the best effect at pH 3.0, with enzyme amount of 62.5 mg/g and immobilization duration of 12 h. Compared with the free u, ehalose synthase, immobilized trehalose synthase showed significantly improved pH stability and thermal stability with repeatable operation, which was conducive to the utilization and storage of enzyme. [ Conclusion] This study provided theoretical basis for the devel- opment of new immobilized trehalose synthase.

Protective roles of trehalose in Pleurotus pulmonarius during heat stress response

High temperature is one of the major abiotic stresses that limit edible mushroom growth and development. The understanding of physiological alterations in response to heat stress and the corresponding mechanisms involved is vital for the breeding of heat-resistant edible mushroom strains. Although trehalose functions as a protectant against abiotic stresses in fungi, the putative role of trehalose in thermotolerance remains to be elucidated. In this study, we found heat stress inhibited the growth of two Pleurotus pulmonarius strains, heat-sensitive and less-sensitive, and the inhibition was more significant for the sensitive strain. Heat stress leads to the increase of lipid peroxidation and intracellular trehalose accumulation, with a higher level in the heat-sensitive strain, and this effect is independent of exogenous trehalose application. In addition, a lower concentration of exogenous trehalose application in sensitive strain than in less-sensitive strain was found to alleviate the inhibition of mycelium growth and further increase the intracellular trehalose concentration by heat stress. Thus, the protective effects of trehalose were more remarkable in the sensitive strain. The activities of intracellular trehalose metabolic enzymes, i.e., trehalose-6-phosphate synthase, trehalose phosphorylase and neutral trehalase, were determined, and our data indicated that the changes of these enzymes activities in the sensitive strain were more beneficial to accumulate trehalose than that in the less-sensitive strain.

Effects of Exogenous Trehalose on the Metabolism of Sugar and Abscisic Acid in Tomato Seedlings Under Salt Stress

Salt stress a ects the growth and development of plants, which results in a decrease in crop quality and yield. In this study, we used tomato seedlings treated with salt and trehalose as experimental materials and analyzed them using the technique for order preference by similarity to ideal solution analysis to select the optimal trehalose concentration for treatment. We also determined the contents of sugar and abscisic acid (ABA) and detected the expression of genes involved in the metabolism of sugar and ABA by quantitative real-time PCR. Results showed that the optimal trehalose concentration was 2 mmol/L for tomato seedlings under salt stress. Exogenous trehalose decreased the starch content and increased the soluble sugar con- tent by a ecting the expression of genes related to the metabolism of starch and soluble sugar. Exogenous trehalose altered the accumulation and distribution of sugar by inducing the upregulation of sugar transporter genes. Furthermore, trehalose increased the ABA content to induce salt stress response by regulating the expression of genes related to the synthesis and metabolism of ABA. In conclusion, trehalose can e ectively alleviate salt stress and enhance salt tolerance of tomato. These ndings provide a novel perspective and a better resource to investigate the salt tolerance mechanism and a new method for alleviating salt stress in tomato.

Drying of Micro-Encapsulated Lactic Acid Bacteria—Effects of Trehalose and Immobilization on Cell Survival and Release Properties

Lactic acid bacteria （LAB） were encapsulated with alginate, gelatin and trehalose additives by the extrusion method and dried at 4 ℃. The microcapsules were generally spherical and had a wrinkled surface with a size of 1.7mm± 0.2mm Trehalose as a carbohydrate source in the culture medium could reduce acid production and performed no function in the positive proliferation of LAB. Using trehalose as a carbohydrate source and protective medittm simultaneously had a benefit in the protection of LAB cells during the storage at 4 ℃. The density of live LAB cells could be 10^7 CFU g^-1 after 8weeks of storage. Cells of LAB could be continuously released from the capsules from the acidic （pH 1.2） to neutral conditions （pH 6.8）. The release amounts and proliferation speeds of LAB cells in neutral medium were much larger and faster than those in acidic conditions. Additionally, nxtmobilization of LAB could improve the survival of cells when they were exposed to acidic medium （pH 1.2） with a survival rate of 76%.

Assessment of Polyamines and Trehalose in Wheat Microspores Culture for Embryogenesis and Green Regenerated Plants

Most aspects of microspore culture protocol have the capacity to cause stress to microspores, hence, less stressful treatments might be required to avoid deleterious effects. In stressed plants, polyamines and trehalose can act as compatible solutes or osmoprotectants by stabilizing proteins and biological membranes. To improve green plant regeneration in wheat microspore culture, this study assessed the effects of polyamines (putrecine, spermidine, spermine) and trehalose on androgenic response namely embryogenesis, green plant regeneration and ploidy of green plants regenerated in three spring wheat genotypes. Microspores of the genotypes produced significant numbers of embryos and green plants among polyamine treatments but trehalose had no effect (P ≤ 0.05). Polyamine treatments for 30 min generally produced more green plants per 100 microspores than the 60 min treatments in all three genotypes. At least three out of twelve polyamine treatments in each genotype improved the production of double haploid plants and seed setting in regenerants. Wheat genotype, concentration and duration of polyamine treatment had significant impact on embryogenesis and regeneration of green plants in this study. The study also showed that polyamines could be used to accelerate cultivar development in wheat breeding.

Studies on Determining Method of Trehalose

Trehalose can be determined by thin layer chromatography and high performance liquid chromatography. But it's difficult to distinguish trehalose from the similar bisaccharides. If the reaction of the reduced bisaccharides with phenyl hydrazine to form osazone is used, then the disturbance of the similar reduced bisaccharides can be rapidly and conveniently excluded, or via the ammoniated-reduced reaction, aliline can be specially bounded to the reduced hydroxyl of the bisaccharides. In that way trehalose can be accurately determined.

Trehalose Synthase Gene Transfer Mediated by Agrobacterium tumefaciens Enhances Resistance to Osmotic Stress in Sugarcane

Trehalose synthase gene (TSase) from Grifola frondosa was transferred into sugarcane (Sac-charum hybrid L.) using Agrobacterium-mediated method to improve sugarcane drought-tolerance. The results indicated that embryogenic callus of sugarcane was sensitive to A. tumefaciens EHA105 strain in the transformation system employed. The high frequency PPT-resistant plants were obtained from transformated with 3 weeks callus after incubation, which reached 4.5% on average. The transgenic plants were confirmed by PCR and Southern analysis. Some transgenic plants showed multiple phenotypic alterations and some plants demonstrated improvement tolerance to osmotic stress.

A Review on the Protection Mechanism of Trehalose on Plant Tissues and Animal Cells

Trehalose is a non-reducing disaccharide composed of glucose molecules connected byα-glycosidic bond.This soluble substance plays an important role of protecting green algae and other lower plants from stress.It can help plants cope with extreme environments such as severe cold,drought and high salinity,regulate the stomatal conductance and water utilization rate of plants,and participate in the growth and metabolism regulation of plants as a signal molecule.As an impermeable cryoprotectant,trehalose is widely used in the refrigeration protection of various animal cells and tissues due to its non-toxicity and high efficiency.According to the research results at home and abroad in recent years,the protection,regulation and mechanism of trehalose on plant tissues and animal cells were summarized,so as to provide a theoretical basis for the further development and utilization of trehalose.

Self-induced Secretion Expression of Trehalose Synthase in Bacillus subtilis WB800n

Bacillus subtilis is a non-pathogenic Gram-positive bacterium that has been widely used to produce industrially and pharmaceutically relevant proteins. Trehalose, a non reducing disaccharide used as protective agent and additive in foodstuffs and pharmaceutical products, can be prepared by trehalose synthase(TreS). The present work aims to construct a robust recombinant B. subtilis to achieve the secretory expression of TreS. In this study, the treS gene from Pseudomonas putida ATCC47054 was amplified by PCR and further cloned and expressed in B. subtilis WB800 N using pHT01 as expression vector. For avoiding the use of inducer, promoter P_(srfA) was used to replace the promoter P_(grac) in pHT01 and verify the activity of recombinant trehalose synthase. The TreS activity assay was employed to evaluate the performance of recombinant B. subtilis W800 N under different phosphate concentrations, carbon sources, carbon source concentrations, nitrogen sources and pH. The results showed that the P_(srfA) promoter had a good regulation effect under pH 8.0 condition, and the enzyme activity reached 6 000 U/L. Using the PhoD as the secretory signal peptide, TreS was effectively secreted, and the extracellular enzyme activity reached 2 100 U/L, accounting for 35% of the total enzyme activity. By optimizing the medium and fermentation conditions, the extracellular enzyme activity reached 6 900 U/L in 5 L of fermentor, and the proportion reached 48%. The pHT01-P_(srfA)-PhoD-treS secretory recombinant B. subtilis constructed in this study has great potential in trehalose synthase production.

Effects of MTG and GSH on Human Sperm Motility and DNA Integrity during Vitrification in the Presence of Trehalose

Limited information exists about the effects of antioxidants on sperm motility and DNA integrity during vitrification in humans. This study compared the effects of reduced glutathione (GSH) and monothioglycerol (MTG) at different concentrations on post-thaw sperm motility and DNA integrity after vitrification in humans using 0.25 M trehalose as a cryoprotective agent, and found that supplementation of MTG or GSH at 0.5 mM resulted in significantly higher (P < 0.05) recovery rates of post-thaw total and progressive motilities. GSH was more powerful than MTG at the same concentration in cryoprotecting sperm motility (38.9% ± 3.6% vs 32.8% ± 2.4% compared to the control 26.8% ± 2.1% in recovery rate of progressive motility), but both had no significant influence on sperm DNA integrity during vitrification. It was concluded that sperm motility is more sensitive to oxidative stress during vitrification than sperm nuclear DNA, and supplementation of MTG or GSH in vitrification medium is beneficial in cryoprotecting sperm motility.

The Effects of Trehalose on the Bioluminescence and Pigmentation of the Phase I Variant of Photorhabdus luminescens

Photorhabdus luminescens is a Gram-negative, bioluminescent, pigment producing enteric bacterium, which is pathogenic to insects and has the capability to undergo phase variation. The phase I variant of P. luminescens exists as a mutualistic symbiont where it plays a critical role in the life-cycle of the soil-dwelling nematode, Heterorhabditis bacteriophora. Both the bacterium and the nematode receive their nutritional requirements from the bioconversion of the insect host which is rich in many macromolecules such as the disaccharide, trehalose. Trehalose is a non-reducing disaccharide of glucose that is formed by an a-1,1-glycosidic bond and is associated with the physiology of many bacteria, insects and nematodes. Trehalose has been shown to be the most abundant storage sugar found within insect hemolymph （1%-2%）. The physicochemical properties of trehalose allow this carbohydrate to act as a stress protectant where it has been implicated with thermal stress, dehydration, and osmotic protection of many microorganisms. Due to these properties, trehalose may allow culture stability of the phase I variant in vitro and in vivo. Traits of the phase I variant that were studied in this work include bioluminescence and the production of the red anthroquinone-derived pigment. The carbohydrates that were utilized in this study were glucose and trehalose; where shake flask cultures of the phase I variant were cultured at room temperature for up to six days in carbohydrate supplemented basal media with increasing carbohydrate concentrations of 0. 1%, 0.5% and 1.0% （v/v）. Relative luminosity, pigmentation and pH were graphed as a function of time, carbohydrate used, and carbohydrate concentration. Data obtained from this study suggests that the supplementation of 1.0% trehalose, when culturing the phase I variant ofP. luminescens, can maintain bioluminosity and pigmentation over extended periods of time （five days） as compared to basal media and basal media supplemented with 1.0% glucose.

Synthesis and Properties of Polyurethane Elastomers with Trehalose Units

In recent years, sugar-derived polymer materials have been actively investigated. In research of polyurethane (PU), sugar has been used as a raw material because it has properties similar to polyol. However, the elastic property of the obtained PU is substantially lost. Hence, the introduction of a sugar unit to PU while maintaining the elastic property remains a challenge in polymer chemistry. Here, we report the synthesis of a polyurethane elastomer (PUE) with a trehalose unit using raw materials such as an aromatic diisocyanate (4,4’-diphenylmethane diisocyanate), polyols including a polyether polyol (polytetramethylene glycol), two polyester polyols (polycaprolactone and polycarbonate diol), and trehalose. Novel PUEs with trehalose units are synthesized by a one-shot method. Trehalose, which has non-reducing properties, is used as sugar. The use of trehalose, which has been scarcely applied to PUE, is essential to obtain the desired PUEs with sugar units.

Expression Analysis of Two Genes Coding for Trehalose-6-Phosphate Synthase(TPS),in Sugarcane(Saccharum spp.)under Water Stress

The accumulation of trehalose (α-D-glucopyranosyl-[1,1]-α-D-glucopyranoside), a sugar with osmoprotectant properties, is very common in microorganisms, invertebrates and in resurrection plants. However, in the majority of higher plants, it is found in trace amounts. Trehalose is synthesized from the UDP-glucose and glucose-6-phosphate in a two-step process with two enzymes, trehalose-6-phosphate synthase or TPS (EC 2.4.1.15 and EC 2.4.1.36) and trehalose-6-phosphate phosphatase or TPP (EC 3.1.3.12). The trehalose-6-phosphate synthase and its product of the trehalose-6-phosphate (T6P) are probable signaling molecules in the carbohydrate metabolism, contributing to enhancing the plants tolerance to water stress. Water scarcity is one of the most important factors that influence productivity in sugarcane (Saccharum spp.) and it activates a cascade of metabolic events and necessary morphologic changes for the survival of the plant under stress. Here we show the in silico expression study of TPS in different libraries from the SUCEST project. Our results showed that the TPS genes are present in all tissues and that they are divided into two subfamilies (class I and II). It is shown that STPS1 belongs to the class I, therefore, it does not have an active phosphatase (TPP) domain, whereas, the STPS2 has an active TPP domain (class II) determined by the presence of phosphatase boxes. Expression analyses based on the semi-quantitative method of the reverse transcription polymerase chain reaction (RT-PCR) show that the STPS1 gene is up-regulated in the tolerant cultivar under stress and down-regulated in susceptible plants. The STPS2 gene does not show considerable variations in the expression levels under the same treatments. The discovery of active genes such as STPS1 and STPS2 in plants under water stress, contributes for the concerning about the cascade of responses in plants under water deficit and points out to target genes for plant breeding.

Three Genes Related to Trehalose Metabolism Affect Sclerotial Development of Rhizoctonia solani AG-1 IA,Causal Agent of Rice Sheath Blight

Trehalose metabolism is related to the sclerotial development of Rhizoctonia solani AG-1 IA,the causal agent of rice sheath blight(RSB).Here,we further elucidated the functions of three genes Rstre,Rstps1 and Rstpp that encode three key enzymes trehalase(TRE),alpha,alpha-trehalosephosphate synthase(TPS1)and trehalose 6-phosphate phosphatase(TPP)in the sclerotial development of R.solani AG-1 IA.Due to the lack of a stable genetic transformation system for R.solani,the heterologous expression of these three genes in Pichia pastoris GS115 was performed.The results showed that reactive oxygen species(ROS)contents and enzyme activities in R.solani decreased significantly in the treatments of the fermentation broths of Rstps1 and Rstpp transformants,and that in the treatment of the fermentation broth of Rstre transformant visibly increased.Furthermore,the fermentation broths of the transformants of all the three genes were added to potato dextrose agar(PDA)medium for the cultivation of R.solani,as a result,the dry weight of sclerotia in each PDA plate containing the fermentation broths of Rstps1 and Rstpp transformants significantly increased compared with the control,and that of Rstre transformant obviously decreased.Finally,178 proteins were found to interact with RSTPS1,and 16 of them were associated with ROS.Taken together,the findings suggest that all these three genes related to trehalose metabolism play important roles in the sclerotial development of R.solani AG-1 IA,and can be used as new targets for the development of novel high-efficiency fungicides for the controlling of RSB.

Protective effect of Scrophularia striata combined with trehalose and cysteine added to diluents on cryopreservd goat epididymal sperm

Objective:To evaluate antioxidant effects of Scrophularia(S.)striata ethanol extract,trehalose and cysteine added to diluents on cryopreserved goat epididymal sperms.Methods:Motility and standard motion parameters of sperm were assessed by using computer assisted sperm motility analysis system.Sperm viability was evaluated by eosin-nigrosin staining method.Hypo-osmotic swelling test was used to evaluate membrane health.Thiobarbituric acid testing was used to measure malondialdehyde(MDA)concentrations.To assess DNA fragmentation,sperm chromatin dispersion test was used.In Experiment 1,treatments consisting of basal Tris diluent supplemented with 25,50 or 100µg/mL of S.striata ethanol extract gave the best concentration to the freezing diluents.Experiment 2 was carried out to compare the best concentration of S.striata ethanol extract(50µg/mL)resulting from the first experiment with 150 mM trehalose and/or 5 mM cysteine alone or in combination.Results:S.striata ethanol extract(50µg/mL)significantly increased sperm viability,motility and progressive motility and at the same time decreased MDA concentration and DNA fragmentation compared to other treatments(P<0.05).In addition,all treatment groups resulted in viability,membrane health,total motility,progressive motility,curvilinear velocity,straightline velocity higher and MDA lower compared to the control group(P<0.05).Acrosome integrity was significantly higher in 50µg/mL of S.striata ethanol extract combined with cysteine,trehalose,or cysteine+trehalose groups than those in the control,trehalose,cysteine,and 50µg/mL of S.striata ethanol extract groups(P<0.05).Regarding DNA,extenders supplemented with 50µg/mL of S.striata ethanol extract,50µg/mL of S.striata ethanol extract+trehalose,and 50µg/mL of S.striata ethanol extract+trehalose+cysteine were superior to other treatments.Conclusions:Adding 50µg/mL of S.striata ethanol extract alone or in combination with trehalose and cysteine can improve the quality of cryopreserved epididymal sperms of goats.

Trehalose ameliorates autophagy dysregulation in aged cortex and acts as an exercise mimetic to delay brain aging in elderly mice

Exercise is recognized as an effective strategy to delay brain aging, which is related to the activation of autophagy. Trehalose is a natural compound that can activate autophagy and exert beneficial effects in delaying brain aging. In this study, we investigated whether trehalose may exert neuroprotection similar to those of exercise in delaying age-related cognitive decline. Fifteen-month-old male C57BL/6 mice underwent swim exercise and/or were treated with 2% trehalose for 12 weeks. Trehalose, exercise and the combination of exercise and trehalose intervention improved the learning and memory of aged mice. They also improved the ratio of LC3-II/LC3-I, the protein level of LC3-II, Bnip3L, and Parkin respectively. Additionally, both exercise and trehalose increased the phosphorylation of AMPK. Exercise decreased cortical phosphorylation of m TOR and S6k, whereas trehalose did not change these cortical levels. These data indicated that exercise and trehalose might modulate autophagy through m TOR-dependent or m TOR-independent pathways, respectively. However, a combination of exercise and trehalose did not play a synergistic role in improving cognitive function and modulation of autophagy. Taken together, our findings suggest that trehalose exerts similar effects to those of exercise in delaying age-related cognitive decline and that it may thus represent an exercise mimetic to delay brain aging.

Comparison of Rapid Freezing and Vitrification for Human Sperm Cryopreservation Using Trehalose as a Cryoprotective Agent

Rapid freezing and vitrification are becoming popular for human sperm cryopreservation;however, it remains unclear which method is better. The aims of the present study were to determine the optimal trehalose concentration and to compare the cryoprotective effects of rapid freezing and vitrification. The results showed that: 1) The optimal trehalose concentration was 0.25 mol/L;2) The post-thaw recovery rates of total and progressive sperm motilities after rapid freezing (38.6% ± 3.0% and 41.1% ± 5.0%) were significantly higher (P 0.05) than that after vitrification (26.1% ± 3.1% and 27.2% ± 1.3%) when 0.5 mL straws were used;3) However, the recovery rates of total and progressive motilities after rapid freezing in 0.5 mL straw (26.7% ± 9.6% and 26.8% ± 8.7%) were significantly lower (P 0.05) than that after vitrification in a novel straw-in-straw system (43.1% ± 4.2% and 41.8% ± 15.5%);and 4) The post-thaw sperm nuclear DNA damage level after rapid freezing in 0.5 mL straw (8.7% ± 2.8%) was not significantly different from that of sperm after vitrification in the straw-in-straw system (9.2% ± 2.5%). It was concluded that rapid freezing is superior to vitrification when using 0.5 mL straws;however, vitrification is superior to rapid freezing when using the straw-in-straw systems.