Trehalose treatment suppresses inflammation, oxidative stress, and vasospasm induced by experimental subarachnoid hemorrhage

A lipid nanoparticle platform incorporating trehalose glycolipid for exceptional mRNA vaccine safety

The rapid development of messenger RNA (mRNA) vaccines formulated with lipid nanoparticles (LNPs) has contributed to control of the COVID-19 pandemic. However, mRNA vaccines have raised concerns about their potential toxicity and clinical safety, including side effects, such as myocarditis, anaphylaxis, and pericarditis. In this study, we investigated the potential of trehalose glycolipids-containing LNP (LNP S050L) to reduce the risks associated with ionizable lipids. Trehalose glycolipids can form hydrogen bonds with polar biomolecules, allowing the formation of a stable LNP structure by replacing half of the ionizable lipids. The efficacy and safety of LNP S050L were evaluated by encapsulating the mRNA encoding the luciferase reporter gene and measuring gene expression and organ toxicity, respectively. Furthermore, mice immunized with an LNP S050L-formulated mRNA vaccine expressing influenza hemagglutinin exhibited a significant reduction in organ toxicity, including in the heart, spleen, and liver, while sustaining gene expression and immune efficiency, compared to conventional LNPs (Con-LNPs). Our findings suggest that LNP S050L, a trehalose glycolipid-based LNP, could facilitate the development of safe mRNA vaccines with improved clinical safety.

Trehalose-induced SIRT1/AMPK activation regulates SREBP-1c/PPAR-α to alleviate lipid accumulation in aged liver

Aging is associated with a disturbance in the regulation of the metabolic function of the liver, which increases the risk of liver and systemic diseases. Trehalose, a natural disaccharide, has been identified to reduce dyslipidemia, hepatic steatosis, and glucose intolerance. However, the roles of trehalose on lipid metabolism in aged liver are unclear which was investigated in this study. Thirty-two male Wistar rats were randomly allocated into four groups (n = 8). Two groups of aged (24 months) and young (4 months) rats were administered 2% trehalose solution orally for 30 days. Control groups of aged and young rats did not receive any treatment. At the end of the treatment period, blood samples and liver tissues were collected. Then the expression of SIRT1, AMPK, SREBP-1c, and PPAR-α and the level of AMPK phosphorylation (p-AMPK) were quantified by real-time polymerase chain reaction and western blotting. Moreover, biochemical parameters and the histopathology of livers were evaluated. Trehalose supplementation increased the level of SIRT1, p-AMPK, and PPAR-α, whereas the level of SREBP-1c was diminished in the liver of old animals. In addition, treatment with trehalose improved histopathological features of senescent livers. Taken together, our results show that old rats developed lipogenesis in the liver which was alleviated with trehalose. Therefore, trehalose may be an effective intervention to reduce the progression of aging-induced liver diseases.

Deferoxamine Mitigates Ferroptosis and Inflammation in Hippocampal Neurons After Subarachnoid Hemorrhage by Activating the Nrf2/TXNRD1 Axis

Ferroptosis is a distinct peroxidation-driven form of cell death tightly involved in subarachnoid hemorrhage (SAH). This study delved into the mechanism of deferoxamine (DFO, an iron chelator) in SAH-induced ferroptosis and inflammation. SAH mouse models were established by endovascular perforation method and injected intraperitoneally with DFO, or intraventricularly injected with the Nrf2 pathway inhibitor ML385 before SAH, followed by detection of neurological function, blood-brain barrier (BBB) permeability, and brain water content. Apoptotic level of hippocampal neurons, symbolic changes of ferroptosis, and levels of pro-inflammatory cytokines were assessed using TUNEL staining, Western blotting, colorimetry, and ELISA. The localization and expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) were detected. HT22 cells were exposed to Hemin as in vitro SAH models and treated with FIN56 to induce ferroptosis, followed by evaluation of the effects of DFO on FIN56-treated HT22 cells. The regulation of Nrf2 in thioredoxin reductase 1 (TXNRD1) was analyzed by co-immunoprecipitation and Western blotting. Moreover, HT22 cells were treated with DFO and ML385 to identify the role of DFO in the Nrf2/TXNRD1 axis. DFO extenuated brain injury, and ferroptosis and inflammation in hippocampal neurons of SAH mice. Nrf2 localized at the CA1 region of hippocampal neurons, and DFO stimulated nuclear translocation of Nrf2 protein in hippocampal neurons of SAH mice. Additionally, DFO inhibited ferroptosis and inflammatory responses in FIN56-induced HT22 cells. Nrf2 positively regulated TXNRD1 protein expression. Indeed, DFO alleviated FIN56-induced ferroptosis and inflammation via activation of the Nrf2/TXNRD1 axis. DFO alleviated neurological deficits, BBB disruption, brain edema, and brain injury in mice after SAH by inhibiting hippocampal neuron ferroptosis via the Nrf2/TXNRD1 axis. DFO ameliorates SAH-induced ferroptosis and inflammatory responses in hippocampal neurons by activating the Nrf2/TXNRD1 axis.

Acacetin inhibits activation of microglia to improve neuroinflammation after subarachnoid hemorrhage through the PERK signaling pathway mediated autophagy

PURPOSE

To explore the effect of acacetin on subarachnoid hemorrhage (SAH) and its possible mechanism.

METHODS

SAH model of rat was established, and intraperitoneally injected with three doses of acacetin. To verify the role of PERK pathway, we used the CCT020312 (PERK inhibitor) and Tunicamycin (activators of endoplasmic reticulum stress). The SAH score, neurological function score, brain edema content, and Evans blue (EB) exudate were evaluated. Western blot was used to determine the expression of inflammation-associated proteins and PERK pathway. The activation of microglia was also determined through Iba-1 detection. TEM and immunofluorescence staining of LC3B were performed to observe the autophagy degree of SAH rats after acacetin. Tunel/NeuN staining, HE and Nissl' staining were performed for neuronal damage.

RESULTS

Acacetin increased the neurological function score, reduce brain water content, Evans blue exudation and SAH scores. The microglia in cerebral cortex were activated after SAH, while acacetin could inhibit its activation, and decreased the expression of TNF-α and IL-6 proteins. The pathological staining showed the severe neuronal damage and increased neuronal apoptosis after SAH, while acacetin could improve these pathological changes. We also visualized the alleviated autophagy after acacetin. The expression of Beclin1 and ATF4 proteins were increased, but acacetin could inhibit them. Acacetin also inactivated PERK pathway, which could improve the neuronal injury and neuroinflammation after SAH, inhibit the microglia activation and the overactivated autophagy through PERK pathway.

CONCLUSION

Acacetin may alleviate neuroinflammation and neuronal damage through PERK pathway, thus having the protective effect on EBI after SAH.

Effect of trehalose on miR-132 and SIRT1 in the hippocampus of aged rats

Aging causes substantial molecular to morphological changes in the brain. The brain cells are more susceptible towards oxidative damage due to impaired antioxidant defense system. Sirtuin1 (SIRT1) is a crucial cellular survival protein, which its gene has been identified as a direct target of microRNA 132 (miR-132). Trehalose contributes to preventing neuronal damage through several mechanisms. However, little is known about the interactive effects of aging and trehalose on the expression pattern of miR-132 and SIRT1 in the hippocampus. Male Wistar rats were divided into four groups. Two groups of aged (24 months) and young (4 months) rats were administered 2% trehalose solution for 30 days. Two other groups of aged and young rats received regular tap water. At the end of treatment, the levels of Sirt1 mRNA and its protein, malondialdehyde, protein carbonyl content, total antioxidant capacity, tumor necrosis factor α (TNF-α), as well as the expression of miR-132 were measured in the hippocampus. We found that trehalose treatment upregulated the expression of SIRT1 and miR-132. Moreover, administration of trehalose enhanced the level of total antioxidant activity whereas reduced the levels of lipid peroxidation, protein carbonyl content, and TNF-α. In conclusion, our data indicated that trehalose restored antioxidant status and alleviated inflammation in the hippocampus which was probably associated with the upregulation of SIRT1 and miR-132.

Ovarian tissue cryopreservation and transplantation: a review on reactive oxygen species generation and antioxidant therapy

Cancer is the leading cause of death worldwide. Fortunately, the survival rate of cancer continues to rise, owing to advances in cancer treatments. However, these treatments are gonadotoxic and cause infertility. Ovarian tissue cryopreservation and transplantation (OTCT) is the most flexible option to preserve fertility in women and children with cancer. However, OTCT is associated with significant follicle loss and an accompanying short lifespan of the grafts. There has been a decade of research in cryopreservation-induced oxidative stress in single cells with significant successes in mitigating this major source of loss of viability. However, despite its success elsewhere and beyond a few promising experiments, little attention has been paid to this key aspect of OTCT-induced damage. As more and more clinical practices adopt OTCT for fertility preservation, it is a critical time to review oxidative stress as a cause of damage and to outline potential ameliorative interventions. Here we give an overview of the application of OTCT for female fertility preservation and existing challenges; clarify the potential contribution of oxidative stress in ovarian follicle loss; and highlight potential ability of antioxidant treatments to mitigate the OTCT-induced injuries that might be of interest to cryobiologists and reproductive clinicians.

The potential therapeutic impacts of trehalose on cardiovascular diseases as the environmental-influenced disorders: An overview of contemporary findings

Cardiovascular diseases (CVDs) as environmental-influenced disorders, are a major concern and the leading cause of death worldwide. A range of therapeutic approaches has been proposed, including conventional and novel methods. Natural compounds offer a promising alternative for CVD treatment due to their ability to regulate molecular pathways with minimal adverse effects. Trehalose is natural compound and disaccharide with unique biological functions and cardio-protective properties. The cardio-protective effects of trehalose are generated through its ability to induce autophagy, which is mediated by the transcription factors TFEB and FOXO1. The stimulation of TFEB plays a significant role in regulating autophagy genes and autophagosome formation. Activation of FOXO1 through dephosphorylation of Foxo1 and blocking of p38 mitogen-activated protein kinase (p38 MAPK) also triggers autophagy dramatically. Trehalose has been shown to reduce CVD risk factors, including atherosclerosis, cardiac remodeling after a heart attack, cardiac dysfunction, high blood pressure, and stroke. It also reduces structural abnormalities of mitochondria, cytokine production, vascular inflammation, cardiomyocyte apoptosis, and pyroptosis. This review provides a molecular overview of trehalose's cardioprotective functions, including its mechanisms of autophagy and its potential to improve CVD symptoms based on clinical evidence.

Trehalose attenuates abdominal aortic aneurysm formation by inducing autophagy in smooth muscle cells

BACKGROUND

Trehalose is a naturally occurring disaccharide, which has been identified as an autophagy inducer and exhibits protective effect in cardiovascular diseases such as myocardial infraction and atherosclerosis. However, the functional role of trehalose in abdominal aortic aneurysm (AAA) remains undefined.

METHODS

To study the effect of trehalose in AAA, trehalose (1 g/kg per day) were given for 14 continuous days in a mouse model of elastase-induced abdominal aortic aneurysm. On day 14, ultrasound was performed to measure aortic diameter before the abdominal aortas were harvested and processed for further analysis. Verhoeff-Van Gieson staining and TUNEL staining were performed on paraffin sections to evaluate vascular histology and apoptosis, immunofluorescence staining and Western-blot were performed to evaluate expression of autophagy markers.

RESULTS

Echocardiography and in situ pictures demonstrated that trehalose attenuated infrarenal aorta dilation. Verhoeff-Van Gieson staining showed elastin degradation was improved in trehalose-treated group. Compared with vehicle-treated mice, trehalose treatment restored smooth muscle cell contractile phenotype with increased α-SMA, Calponin and Myh11 expression. Furthermore, trehalose also attenuated cell apoptosis and leukocytes infiltration. Importantly, trehalose induced autophagy with decrease SQSTM1/p62 accumulation, increased lamp2 expression and LC3B conversion.

CONCLUSION

Trehalose attenuated AAA progression with decreased inflammation and restored SMC contractile phenotype by inducing autophagy. These results demonstrated the therapeutic potential of trehalose in AAA.

Anti-arthritic and Antioxidant Effects of Trehalose in an Experimental Model of Arthritis

BACKGROUND

The purpose of the present study was to study the potential anti-arthritic and antioxidant effects of trehalose in an experimental model of complete Freund's adjuvant (CFA)-induced arthritis.

METHODS

Arthritis was induced via subcutaneous injection of CFA (0.1) into the right footpad of each rat. Trehalose (10 mg/kg per day) and indomethacin (5 mg/kg) as a reference drug were intraperitoneally injected into CFA-induced arthritic rats from days 0 to 21. Changes in paw volume, pain responses, arthritic score, and oxidative/antioxidative parameters were determined.

RESULTS

Trehalose administration could significantly decrease arthritis scores (p <0.01) and paw edema (p <0.001), and significantly increase the nociceptive threshold (p <0.05) in CFA-induced arthritic rats. Trehalose also significantly reduced the pro-oxidant-antioxidant balance values when compared to CFA treatment alone. In addition, no significant difference was found between the trehalose group and indomethacin as a positive control group.

CONCLUSION

The current study suggests that trehalose has a protective effect against arthritis, which may be mediated by antioxidative effects of this disaccharide.

Beneficial effects of trehalose and gentiobiose on human sperm cryopreservation

The protection of human sperm during cryopreservation is of great importance to infertility. Recent studies have shown that this area is still a long way from its ultimate aim of maintaining the maximum viability of sperm in cryopreservation. The present study used trehalose and gentiobiose to prepare the human sperm freezing medium during the freezing-thawing. The freezing medium of sperm was prepared with these sugars, and the sperm were then cryopreserved. The viable cells, sperm motility parameters, sperm morphology, membrane integrity, apoptosis, acrosome integrity, DNA fragmentation, mitochondrial membrane potential, reactive oxygen radicals, and malondialdehyde concentration was evaluated using standard protocols. A higher percentage of the total and progressive motility, rate of viable sperm, cell membrane integrity, DNA and acrosome integrity, and mitochondrial membrane potential were observed in the two frozen treatment groups compared to the frozen control. The cells had less abnormal morphology due to treatment with the new freezing medium than the frozen control. The higher malondialdehyde and DNA fragmentation were significantly observed in the two frozen treatment groups than in the frozen control. According to the results of this study, the use of trehalose and gentiobiose in the sperm freezing medium is a suitable strategy for sperm freezing to improve its motion and cellular parameters.

GPR18 Agonist Resolvin D2 Reduces Early Brain Injury in a Rat Model of Subarachnoid Hemorrhage by Multiple Protective Mechanisms

Early brain injury (EBI) is the early phase of secondary complications arising from subarachnoid hemorrhage (SAH). G protein-coupled receptor 18 (GPR18) can exert neuroprotective effects during ischemia. In this study, we investigated the roles of GPR18 in different brain regions during EBI using a GPR18 agonist, resolvin D2 (RvD2). Location and dynamics of GPR18 expression were assessed by immunohistochemistry and western blotting in a rat model of SAH based on endovascular perforation. RvD2 was given intranasally at 1 h after SAH, and SAH grade, brain water content and behavior were assayed before sacrifice. TUNEL and dihydroethidium staining of the cortex were performed at 24 h after SAH. Selected brain regions were also examined for pathway related proteins using immunofluorescence and Western blotting. We found that GPR18 was expressed in meninges, hypothalamus, cortex and white matter before EBI. After SAH, GPR18 expression was increased in meninges and hypothalamus but decreased in cortex and white matter. RvD2 improved neurological scores and brain edema after SAH. RvD2 attenuated mast cell degranulation and reduced expression of chymase and tryptase expression in the meninges. In the hypothalamus, RvD2 attenuated inflammation, increased expression of proopiomelanocortin and interleukin-10, as well as decreased expression of nerve peptide Y and tumor necrosis factor-α. In cortex, RvD2 alleviated oxidative stress and apoptosis, and protected the blood-brain barrier. RvD2 also ameliorated white matter injury by elevating myelin basic protein and suppressing amyloid precursor protein. Our results suggest that GPR18 may help protect multiple brain regions during EBI, particularly in the cortex and hypothalamus. Upregulating GPR18 by RvD2 may improve neurological functions in different brain regions via multiple mechanisms.

Trehalose-Carnosine Prevents the Effects of Spinal Cord Injury Through Regulating Acute Inflammation and Zinc(II) Ion Homeostasis

Spinal cord injury (SCI) leads to long-term and permanent motor dysfunctions, and nervous system abnormalities. Injury to the spinal cord triggers a signaling cascade that results in activation of the inflammatory cascade, apoptosis, and Zn(II) ion homeostasis. Trehalose (Tre), a nonreducing disaccharide, and L-carnosine (Car), (β-alanyl-L-histidine), one of the endogenous histidine dipeptides have been recognized to suppress early inflammatory effects, oxidative stress and to possess neuroprotective effects. We report on the effects of the conjugation of Tre with Car (Tre-car) in reducing inflammation in in vitro and in vivo models. The in vitro study was performed using rat pheochromocytoma cells (PC12 cell line). After 24 h, Tre-car, Car, Tre, and Tre + Car mixture treatments, cells were collected and used to investigate Zn²⁺ homeostasis. The in vivo model of SCI was induced by extradural compression of the spinal cord at the T6-T8 levels. After treatments with Tre, Car and Tre-Car conjugate 1 and 6 h after SCI, spinal cord tissue was collected for analysis. In vitro results demonstrated the ionophore effect and chelating features of L-carnosine and its conjugate. In vivo, the Tre-car conjugate treatment counteracted the activation of the early inflammatory cascade, oxidative stress and apoptosis after SCI. The Tre-car conjugate stimulated neurotrophic factors release, and influenced Zn²⁺ homeostasis. We demonstrated that Tre-car, Tre and Car treatments improved tissue recovery after SCI. Tre-car decreased proinflammatory, oxidative stress mediators release, upregulated neurotrophic factors and restored Zn²⁺ homeostasis, suggesting that Tre-car may represent a promising therapeutic agent for counteracting the consequences of SCI.

Antioxidant and Anti-Inflammatory Activity of Five Medicinal Mushrooms of the Genus Pleurotus

Within the group of higher fungi, edible medicinal mushrooms have a long history of being used as food and in folk medicine. These species contain biologically active substances with many potential beneficial effects on human health. The Pleurotus genus is representative of medicinal mushrooms because Pleurotus ostreatus is one of the most commonly cultivated culinary mushrooms. In our study, we focused on lesser-known species in the genus Pleurotus and measured their antioxidant and anti-inflammatory activity. We prepared extracts of the mushrooms and analyzed them using HPLC−HRMS, GC−MS, and ¹H-NMR. Significant differences in biological activities were found among the Pleurotus spp. extracts. A MeOH extract of P. flabellatus was the most active as a radical scavenger with the highest ORAC, while a chloroform extract had significant anti-inflammatory COX-2 activity. The 80% MeOH extract of P. flabellatus contained the highest amounts of ergosterol, ergothioneine, and mannitol. The 80% MeOH extract of P. ostreatus Florida was the most active in the NF-κB inhibition assay and had the highest content of β-glucans (43.3% by dry weight). Given the antioxidant and anti-inflammatory properties of P. flabellatus, the potential therapeutic usefulness of this species is worth evaluating through in-depth investigations and confirmation by clinical trials.

Sweet taste receptor agonists attenuate macrophage IL-1β expression and eosinophilic inflammation linked to autophagy deficiency in myeloid cells

BACKGROUND

Eosinophilic inflammation is a hallmark of refractory chronic rhinosinusitis (CRS) and considered a major therapeutic target. Autophagy deficiency in myeloid cells plays a causal role in eosinophilic CRS (ECRS) via macrophage IL-1β overproduction, thereby suggesting autophagy regulation as a potential therapeutic modality. Trehalose is a disaccharide sugar with known pro-autophagy activity and effective in alleviating diverse inflammatory diseases. We sought to investigate the therapeutic potential of autophagy-enhancing agent, trehalose, or related sugar compounds, and the underlying mechanism focusing on macrophage IL-1β production in ECRS pathogenesis.

METHODS

We investigated the therapeutic effects of trehalose and saccharin on macrophage IL-1β production and eosinophilia in the mouse model of ECRS with myeloid cell-specific autophagy-related gene 7 (Atg7) deletion. The mechanisms underlying their anti-inflammatory effects were assessed using specific inhibitor, genetic knockdown or knockout, and overexpression of cognate receptors.

RESULTS

Unexpectedly, trehalose significantly attenuated eosinophilia and disease pathogenesis in ECRS mice caused by autophagy deficiency in myeloid cells. This autophagy-independent effect was associated with reduced macrophage IL-1β expression. Various sugars recapitulated the anti-inflammatory effect of trehalose, and saccharin was particularly effective amongst other sugars. The mechanistic study revealed an involvement of sweet taste receptor (STR), especially T1R3, in alleviating macrophage IL-1β production and eosinophilia in CRS, which was supported by genetic depletion of T1R3 or overexpression of T1R2/T1R3 in macrophages and treatment with the T1R3 antagonist gurmarin.

CONCLUSION

Our results revealed a previously unappreciated anti-inflammatory effect of STR agonists, particularly trehalose and saccharin, and may provide an alternative strategy to autophagy modulation in the ECRS treatment.

Disaccharide Trehalose in Experimental Therapies for Neurodegenerative Disorders: Molecular Targets and Translational Potential

Induction of autophagy is a prospective approach to the treatment of neurodegeneration. In the recent decade, trehalose attracted special attention. It is an autophagy inducer with negligible adverse effects and is approved for use in humans according to FDA requirements. Trehalose has a therapeutic effect in various experimental models of diseases. This glucose disaccharide with a flexible α-1-1'-glycosidic bond has unique properties: induction of mTOR-independent autophagy (with kinase AMPK as the main target) and a chaperone-like effect on proteins imparting them natural spatial structure. Thus, it can reduce the accumulation of neurotoxic aberrant/misfolded proteins. Trehalose has an anti-inflammatory effect and inhibits detrimental oxidative stress partially owing to the enhancement of endogenous antioxidant defense represented by the Nrf2 protein. The disaccharide activates lysosome and autophagosome biogenesis pathways through the protein factors TFEB and FOXO1. Here we review various mechanisms of the neuroprotective action of trehalose and touch on the possibility of pleiotropic effects. Current knowledge about specific features of trehalose pharmacodynamics is discussed. The neuroprotective effects of trehalose in animal models of major neurodegenerative disorders such as Alzheimer's, Parkinson's, and Huntington's diseases are examined too. Attention is given to translational transition to clinical trials of this drug, especially oral and parenteral routes of administration. Besides, the possibility of enhancing the therapeutic benefit via a combination of mTOR-dependent and mTOR-independent autophagy inducers is analyzed. In general, trehalose appears to be a promising multitarget tool for the inhibition of experimental neurodegeneration and requires thorough investigation of its clinical capabilities.

Rediscovery of 4-Trehalosamine as a Biologically Stable, Mass-Producible, and Chemically Modifiable Trehalose Analog

Nonreducing disaccharide trehalose is used as a stabilizer and humectant in various products and is a potential medicinal drug, showing curative effects on the animal models of various diseases. However, its use is limited as it is hydrolyzed by trehalase, a widely expressed enzyme in multiple organisms. Several trehalose analogs are prepared, including a microbial metabolite 4-trehalosamine, and their high biological stability is confirmed. For further analysis, 4-trehalosamine is selected as it shows high producibility. Compared with trehalose, 4-trehalosamine exhibits better or comparable protective activities and a high buffer capacity around the neutral pH. Another advantage of 4-trehalosamine is its chemical modifiability: simple reactions produce its various derivatives. Labeled probes and detergents are synthesized in one-pot reactions to exemplify the feasibility of their production, and their utility is confirmed for their respective applications. The labeled probes are used for mycobacterial staining. Although the derivative detergents can be effectively used in membrane protein research, long-chain detergents show 1000-3000-fold stronger autophagy-inducing activity in cultured cells than trehalose and are expected to become a drug lead and research reagent. These results indicate that 4-trehalosamine is a useful trehalose substitute for various purposes and a material to produce new useful derivative substances.

Trehalose ameliorates prodromal non-motor deficits and aberrant protein accumulation in a rotenone-induced mouse model of Parkinson's disease

Trehalose has been recently revealed as an attractive candidate to prevent and modify Parkinson's disease (PD) progression by regulating autophagy; however, studies have only focused on the reduction of motor symptoms rather than the modulation of disease course from prodromal stage. This study aimed to evaluate whether trehalose has a disease-modifying effect at the prodromal stage before the onset of a motor deficit in 8-week-old male C57BL/6 mice exposed to rotenone. We found significant decrease in tyrosine hydroxylase immunoreactivity in the substantia nigra and motor dysfunction after 2 weeks rotenone treatment. Mice exposed to rotenone for a week showed an accumulation of protein aggregates in the brain and prodromal non-motor deficits, such as depression and olfactory dysfunction, prior to motor deficits. Trehalose significantly improved olfactory dysfunction and depressive-like behaviors and markedly reduced α-synuclein and p62 deposition in the brain. Trehalose further ameliorated motor impairment and loss of nigral tyrosine hydroxylase-positive cells in rotenone-treated mice. We demonstrated that prodromal non-motor signs in a rotenone-induced PD mouse model are associated with protein aggregate accumulation in the brain and that an autophagy inducer could be valuable to prevent PD progression from prodromal stage by regulating abnormal protein accumulation.

2-PMAP Ameliorates Cerebral Vasospasm and Brain Injury after Subarachnoid Hemorrhage by Regulating Neuro-Inflammation in Rats

A subarachnoid hemorrhage (SAH), leading to severe disability and high fatality in survivors, is a devastating disease. Neuro-inflammation, a critical mechanism of cerebral vasospasm and brain injury from SAH, is tightly related to prognoses. Interestingly, studies indicate that 2-[(pyridine-2-ylmethyl)-amino]-phenol (2-PMAP) crosses the blood-brain barrier easily. Here, we investigated whether the vasodilatory and neuroprotective roles of 2-PMAP were observed in SAH rats. Rats were assigned to three groups: sham, SAH and SAH+2-PMAP. SAHs were induced by a cisterna magna injection. In the SAH+2-PMAP group, 5 mg/kg 2-PMAP was injected into the subarachnoid space before SAH induction. The administration of 2-PMAP markedly ameliorated cerebral vasospasm and decreased endothelial apoptosis 48 h after SAH. Meanwhile, 2-PMAP decreased the severity of neurological impairments and neuronal apoptosis after SAH. Furthermore, 2-PMAP decreased the activation of microglia and astrocytes, expressions of TLR-4 and p-NF-κB, inflammatory markers (TNF-α, IL-1β and IL-6) and reactive oxygen species. This study is the first to confirm that 2-PMAP has vasodilatory and neuroprotective effects in a rat model of SAH. Taken together, the experimental results indicate that 2-PMAP treatment attenuates neuro-inflammation, oxidative stress and cerebral vasospasm, in addition to ameliorating neurological deficits, and that these attenuating and ameliorating effects are conferred through the TLR-4/NF-κB pathway.

Pregabalin Protects Brain Tissue from Subarachnoid Hemorrhage by Enhancing HIF-1α/eNOS Signaling and VEGF Production

OBJECTIVE

We investigated the effects of different doses of pregabalin on the pathophysiologic changes in early brain injury after subarachnoid hemorrhage (SAH) in rats.

METHODS

Thirty-eight Wistar albino rats were divided into 4 groups: control (n = 8), SAH (n = 10), SAH plus 30 mg/kg/day of pregabalin (n = 10), and SAH plus 60 mg/kg/day of pregabalin (n = 10). SAH was induced with 0.3 mL of autologous blood injected to the cisterna magna of rats. Pregabalin was administered intraperitoneally. Oxidative stress markers, mRNA expression of endothelial nitric oxide synthase, hypoxia-inducible factor-1α, and vascular endothelial growth factor, and histopathological changes were evaluated.

RESULTS

Pregabalin increased mRNA expression of endothelial nitric oxide synthase, hypoxia-inducible factor-1α, and vascular endothelial growth factor in a dose-dependent manner. Significant improvement in the histopathological parameters was observed at 60 mg/kg, including a decrease in diffuse hemorrhagic areas, edema and apoptotic bodies in the associated cortical area, evident vacuolization in the hippocampal area, and apoptotic bodies. However, these improvements were not observed with the lower dose (30 mg/kg). In contrast, the antioxidant effect was greater with 30 mg/kg of pregabalin than with 60 mg/kg.

CONCLUSIONS

Although the antioxidant effect was significant with the lower dose of pregabalin, the anti-inflammatory effects via vasodilatation were more marked with the higher dose. Significant improvements in the histopathological changes were observed with the higher dose of pregabalin. The dose-dependent effects of pregabalin on SAH should be evaluated in animal studies as a function of time and in the acute and chronic phases.

Valproic Acid Reduces Vasospasm through Modulation of Akt Phosphorylation and Attenuates Neuronal Apoptosis in Subarachnoid Hemorrhage Rats

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating emergent event associated with high mortality and morbidity. Survivors usually experience functional neurological sequelae caused by vasospasm-related delayed ischemia. In this study, male Sprague-Dawley rats were randomly assigned to five groups: sham (non-SAH) group, SAH group, and three groups with SAH treated with different doses of valproic acid (VPA) (10, 20, 40 mg/kg, once-daily, for 7 days). The severity of vasospasm was determined by the ratio of cross-sectional areas to intima-media thickness of the basilar arteries (BA) on the seventh day after SAH. The BA showed decreased expression of phospho-Akt proteins. The dentate gyrus showed increased expression of cleaved caspase-3 and Bax proteins and decreased expression of Bcl-2, phospho-ERK 1/2, phospho-Akt and acetyl-histone H3 proteins. The incidence of SAH-induced vasospasm was significantly lower in the SAH group treated with VPA 40 mg/kg (p < 0.001). Moreover, all groups treated with VPA showed reversal of the above-mentioned protein expression in BA and the dentate gyrus. Treatment with VPA upregulated histone H3 acetylation and conferred anti-vasospastic and neuro-protective effects by enhancing Akt and/or ERK phosphorylation. This study demonstrated that VPA could alleviate delayed cerebral vasospasm induced neuro-apoptosis after SAH.

Trehalose preconditioning for transient global myocardial ischemia in rats

Autophagy is an intracellular pathway that degrades unnecessary proteins and organelles and provides energy substrates during cellular ischemic conditions. Although pharmacological myocardial preconditioning with an autophagy inducer has been reported to protect cells against ischemic reperfusion (I/R), the effects of preconditioning using naturally occurring substances are still unknown. We aimed to examine whether autophagic preconditioning with trehalose improves cardiac function after myocardial stunning by global ischemia in rats. Rat hearts were perfused by oxygenized Krebs Henseleit (KH) solution in Langendorff system. Ten rats were randomized into the following two groups according to the perfusates during the preconditioning: control (KH solution only, n = 5) and trehalose (KH + 2% trehalose, n = 5). After the 35-min preconditioning period and subsequent 20 min of global ischemia, the hearts were reperfused for 60 min. Cardiac function was assessed during the reperfusion. To evaluate autophagy, myocardial protein expression of microtubule-associated protein light chain 3 (LC3) II was evaluated by western blotting. During I/R, a systolic functional parameter, maximum dP/dt was significantly higher; meanwhile, coronary flow tended to be higher in the trehalose group than in the control group. Myocardial LC3-II expression after preconditioning was higher in the trehalose group than in the control group and decreased to the control level after I/R. In conclusion, in a rat model of global myocardial ischemia, trehalose preconditioning improved cardiac function during I/R. Further studies would be needed to identify the mechanism and effects of trehalose preconditioning.

A head-to-head comparison review of biological and toxicological studies of isomaltulose, d-tagatose, and trehalose on glycemic control

Diabetes mellitus is the most common metabolic disorder contributing to significant morbidity and mortality in humans. Different preventive and therapeutic agents, as well as various pharmacological strategies or non-pharmacological tools, improve the glycemic profile of diabetic patients. Isomaltulose, d-tagatose, and trehalose are naturally occurring, low glycemic sugars that are not synthesized by humans but widely used in food industries. Various studies have shown that these carbohydrates can regulate glucose metabolism and provide support in maintaining glucose homeostasis in patients with diabetes, but also can improve insulin response, subsequently leading to better control of hyperglycemia. In this review, we discussed the anti-hyperglycemic effects of isomaltulose, D-tagatose, and trehalose, comparing their properties with other known sweeteners, and highlighting their importance for the development of the pharmaceutical and food industries.

Trehalose and N-Acetyl Cysteine Alleviate Inflammatory Cytokine Production and Oxidative Stress in LPS-Stimulated Human Peripheral Blood Mononuclear Cells

Background: Evidence has shown that inflammation and oxidative stress are implicated in the development of a great number of human diseases. Trehalose possesses various biological effects including antioxidant and anti-inflammatory activities. However, there is little data on the effects of trehalose on human cells including peripheral blood mononuclear cells (PBMCs). Here, we aimed to investigate whether trehalose could attenuate oxidative stress and inflammation induced by lipopolysaccharides (LPS) in PBMCs.Methods: The enzyme-linked immunosorbent assay (ELISA) and RT-PCR were used to assess the levels of inflammatory cytokines. To investigate the phosphorylation of c-Jun N-terminal kinase (JNK) and NF-κB, western blot analysis was utilized. Oxidant-antioxidant markers were assessed using ELISA and colorimetric procedures.Results: The results revealed that trehalose significantly mitigated the effect of LPS on the phosphorylation of JNK and NF-κB-P65 (p < .00). This mitigation was associated with significantly reduced levels of inflammatory cytokines IL-6, TNF-α, and IL-1β and increased levels of anti-inflammatory cytokine IL-10 (P < .05). The antioxidant N-acetyl cysteine (NAC) also showed similar effects on JNK and NF-κB-P65 phosphorylation and inflammatory cytokines (p < .00). Furthermore, trehalose alleviated oxidative stress in LPS-stimulated PBMCs as it reversed the altered levels of malondialdehyde and total thiols (p ≤ .05) and restored the activity of antioxidant enzymes glutathione peroxidase and manganese superoxide dismutase (p < .001).Conclusion: The results of this study indicated that trehalose prevented inflammation and oxidative stress in the LPS-stimulated PBMCs, providing evidence for the benefits of trehalose as a potential therapeutic agent in inflammatory conditions.Abbreviations: LPS: Lipopolysaccharide; NAC: N-Acetyl cysteine; ROS: Reactive oxygen species; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-alpha; SOD: Superoxide dismutase; GPx: Glutathione peroxidase; MDA: Malondialdehyde; MAPK: Mitogen-activated protein kinases; JNK: c-Jun N-terminal kinase; NF-κB: Nuclear factor kappa-light-chain-enhancer of activated B cells.

Antioxidant Effects of Trehalose in an Experimental Model of Type 2 Diabetes

BACKGROUND

Oxidative stress that occurs as a consequence of the imbalance between antioxidant activity and free radicals can contribute in the pathogenesis of metabolic disorders, such as type 2 diabetes mellitus (T2DM). Antioxidant therapies have been proposed as possible approaches to treat and attenuate diabetic complications. The purpose of this study was to evaluate potential antioxidant effects of trehalose on oxidative indices in a streptozotocin (STZ)-induced diabetic rat model.

METHODS

Diabetic rats were divided randomly into five treatment groups (six rats per group). One test group received 45 mg/kg/day trehalose via intraperitoneal injection, and another received 1.5 mg/kg/day trehalose via oral gavage for 4 weeks. Three control groups were also tested including nondiabetic rats as a normal control (NC), a nontreated diabetic control (DC), and a positive control given 200 mg/kg/day metformin. Levels of thiol groups (-SH), and serum total antioxidant capacity were measured between control and test groups. In addition, superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were assessed.

RESULTS

In both oral and injection trehalose-treated groups, a marked increase was observed in serum total antioxidant capacity (TAC) (p > 0.05) and thiol groups (-SH) (p < 0.05). Also, SOD and GPx activities were increased after 4 weeks of treatment with trehalose.

CONCLUSION

In conclusion, the present results indicate ameliorative effects of trehalose on oxidative stress, with increase antioxidant enzyme activities in STZ-induced diabetic rats.

Possible Therapeutic Use of Natural Compounds Against COVID-19

The outbreak of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has led to coronavirus disease-19 (COVID-19); a pandemic disease that has resulted in devastating social, economic, morbidity and mortality burdens. SARS-CoV-2 infects cells following receptor-mediated endocytosis and priming by cellular proteases. Following uptake, SARS-CoV-2 replicates in autophagosome-like structures in the cytosol following its escape from endolysosomes. Accordingly, the greater endolysosome pathway including autophagosomes and the mTOR sensor may be targets for therapeutic interventions against SARS-CoV-2 infection and COVID-19 pathogenesis. Naturally existing compounds (phytochemicals) through their actions on endolysosomes and mTOR signaling pathways might provide therapeutic relief against COVID-19. Here, we discuss evidence that some natural compounds through actions on the greater endolysosome system can inhibit SARS-CoV-2 infectivity and thereby might be repurposed for use against COVID-19.

Interleukin-6: Important Mediator of Vasospasm Following Subarachnoid Hemorrhage

The correlation of neuroinflammation with the development of cerebral vasospasm following subarachnoid hemorrhage has been well documented in the literature; both clinical and preclinical. The exact mechanisms by which this process occurs, however, are poorly elucidated. Recent evidence indicates that interleukin-6 is not only an important prognostic biomarker for subarachnoid hemorrhage and subsequent vasospasm development but also an integral component in the progression of injury following initial insult. In this review, we briefly highlight other pathways under investigation and focus heavily on what has been discovered regarding the role of interleukin 6 and cerebral vasospasm following subarachnoid hemorrhage. A proposed mechanistic pathway is highlighted in written and graphical format. A discussion regarding the human correlative findings and initial pre-clinical mechanistic studies is addressed. Finally, in the future investigation section, innovative developments and a clear description of areas warranting further scientific inquiry are emphasized. This review will catalyze continued discovery in this area of emerging significance and aid in the quest for effective vasospasm treatment where limited clinical therapeutics currently exist.

Astragaloside IV alleviates the brain damage induced by subarachnoid hemorrhage via PI3K/Akt signaling pathway

Subarachnoid hemorrhage (SAH) caused brain damage accounts for more than 20 % death of patients with cerebrovascular diseases. We aimed to investigate the effects of Astragaloside IV (AS-IV) on SAH-induced brain damage and its underlying mechanism. SAH rat model was established and treated with or without AS-IV. Brain injury and function were evaluated by neurological score, brain water content, Nissl staining, and behavioral experiments using Morris water maze. The protein expression related to SAH caused inflammation and neuron apoptosis were assessed. As expected, after 24 h of SAH, Garcia score, beam balance score and the number of intact neurons were significantly reduced in SAH rats compared to sham rats, but AS-IV treatment dramatically elevated the two scores and the number of intact neuron number. Brain water content that increased after SAH was also declined in AS-IV treated rats compared to untreated rats. In addition, SAH rats treated with AS-IV also showed better neurological outcomes than untreated SAH rats including shorter escape time and swimming distance, longer quadrant stay in the Morris water maze and increased fall latency from the rod rotating. In addition, in the SAH rats, the anti-apoptosis pathway phosphoinositide 3-kinase (PI3K)/ protein kinase B (Akt) was activated while nuclear factor-κB (NF-κB) signaling was markedly repressed by AS-IV. Several apoptosis associated genes including FoxO1, Bim, Bax and a typical apoptosis marker cleaved-caspase-3 were all downregulated by AS-IV. In conclusion, this study found a protective role of AS-IV in SAH-induced brain injury through regulating PI3K and NF-κB signaling pathways.

Trehalose alleviates cadmium-induced brain damage by ameliorating oxidative stress, autophagy inhibition, and apoptosis

Cadmium (Cd) is a persistent environmental contaminant and induces neurotoxicity in animals. Trehalose (Tre) exhibits powerful neuroprotective effects in certain brain injury models. Herein, we revealed the specific molecular mechanism underlying the protective effects of Tre against Cd-induced brain damage in rats. Firstly, the results showed that Tre significantly ameliorated brain pathological injury induced by Cd. Secondly, Cd-induced down-regulation of total anti-oxidation capacity (T-AOC) and up-regulation of methane dicarboxylic aldehyde (MDA) in brain tissues were significantly reversed by Tre treatment. Importantly, the augmentation of nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) caused by Cd was significantly inhibited by Tre treatment. Thirdly, the levels of autophagy marker proteins were measured and the results showed that Tre significantly reversed the up-regulation of light chain 3II (LC-3II) and sequestosome 1 (SQSTM-1/p62) caused by Cd exposure. Finally, the apoptosis rate and the levels of apoptosis marker proteins including B cell leukemia/lymphoma 2 (Bcl2) and Bcl2-associated X protein (Bax) were also measured and the results showed that Cd-induced apoptosis was markedly inhibited by Tre treatment. Collectively, our data suggested that Tre exerted its neuroprotective effects by ameliorating oxidative stress, autophagy inhibition, and apoptosis induced by Cd in rat brains. In addition, the Nrf2 signaling pathway, which is continuously activated by Cd, may contribute to brain injury.

The effect of trehalose on intracellular and extracellular nucleotide metabolism. A pilot study

Trehalose is a stable, non-reducing disaccharide, which was found recently to stimulate autophagy, limit the inflammatory response and suppress the growth of specific types of cancer. Purinergic signaling and dysregulation of nucleotide metabolism are the key factors, which play a role in the pathophysiology of cancer development and inflammation. Therefore, this study took a novel approach and aimed to find the effect of trehalose on intracellular, and the extracellular metabolism of nucleotides and NAD + in endothelial and breast cancer cells. The results of this study indicated that in vitro concentrations of trehalose between 0.5 and 5 mM reduced the levels of intracellular NAD + in breast cancer cells. The decrease of intracellular guanosine, independent of GTP energy metabolism, was also observed in both endothelial and cancer cells. Trehalose decreased the activity of ecto-adenosine deaminase. Maximal 3-fold decrease in adenosine deamination was observed in both cell types. Trehalose causes changes in both intracellular and extracellular nucleotide metabolism that is more significant in cancer cells than in endothelium. This effect may have therapeutic potential in cancer and endothelial dysfunction, but its full clarification requires further studies.

Trehalose against Alzheimer's Disease: Insights into a Potential Therapy

Trehalose is a natural disaccharide with a remarkable ability to stabilize biomolecules. In recent years, trehalose has received growing attention as a neuroprotective molecule and has been tested in experimental models for different neurodegenerative diseases. Although the underlying neuroprotective mechanism of trehalose's action is unclear, one of the most important hypotheses is autophagy induction. The chaperone-like activity of trehalose and the ability to modulate inflammatory responses has also been reported. There is compelling evidence that the dysfunction of autophagy and aggregation of misfolded proteins contribute to the pathogenesis of Alzheimer's disease (AD) and other neurodegenerative disorders. Therefore, given the linking between trehalose and autophagy induction, it appears to be a promising therapy for AD. Herein, the published studies concerning the use of trehalose as a potential therapy for AD are summarized, providing a rationale for applying trehalose to reduce Alzheimer's pathology.

Trehalose decreases blood clotting in the cerebral space after experimental subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) frequently results in several serious complications, such as cerebral vasospasm. We previously reported the effect of trehalose on vasospasm, inflammatory responses, and lipid peroxidation induced by blood exposure. Herein, to further elucidate the mechanism of action of trehalose, we investigated whether or not post-administration of trehalose can directly influence blood clotting in the cistern. As a result of trehalose injection after the onset of experimental SAH, blood clotting around the basilar artery was clearly inhibited. We also found that trehalose positively impacted coagulation and fibrinolysis parameters in rat, rabbit and human plasma in vitro. These findings suggest that trehalose has suppressive effects on blood clotting in addition to vasospasm, inflammatory responses, and lipid peroxidation after SAH.

SILAC-based proteomic profiling of the suppression of TGF-β1-induced lung fibroblast-to-myofibroblast differentiation by trehalose

Fibroblast-to-myofibroblast differentiation is one of the most important characteristics of pulmonary fibrosis, and screening natural compounds targeting fibroblast differentiation is always a promising approach to discover drug candidates for treatment of pulmonary fibrosis. Trehalose reportedly has many potential medical applications, especially in treating neurodegeneration diseases. However, it remains unclear whether trehalose suppresses lung fibroblast differentiation. In this work, we found that trehalose decreased the expression levels of α-smooth muscle actin (α-SMA) following the induction of transforming growth factor β1 (TGF-β1) in pretreatment, co-treatment, and post-treatment groups. Trehalose also reduced the production of type I collagen, lung fibroblast-containing gel contractility and cell filament formation in TGF-β1-stimulated MRC-5 cells. Although trehalose is a known autophagy inducer, our results showed that its suppressive effect on fibroblast differentiation was not via trehalose-induced autophagy. And it did not affect canonical TGFβ/Smad2/3 pathway. By applying proteomic profiling technology, we demonstrated that the downregulation of β-catenin was involved in the trehalose-repressive action on fibroblast differentiation. The β-catenin agonist, SKL2001, reversed the suppressive effect of trehalose on fibroblast differentiation. Overall, these experiments demonstrated that trehalose suppressed fibroblast differentiation via the downregulation of β-catenin, but not through canonical autophagy and TGFβ/Smad2/3 pathway, which is not only a novel understanding of trehalose, but also quite helpful for in vivo research of trehalose on pulmonary fibrosis in future.

SIRT3 protects against early brain injury following subarachnoid hemorrhage via promoting mitochondrial fusion in an AMPK dependent manner

Background

Subarachnoid hemorrhage (SAH), an acute cerebrovascular accident, features with its high death and disability rate. Sirtuin3 (SIRT3) is a NAD+ dependent deacetylase which mainly located in mitochondria. Reduced SIRT3 function was indicated to involve in many disorders of central nervous system. Herein, we aimed to explore the neuroprotective effects of SIRT3 on SAH and to furtherly explore the underlying mechanisms.

Methods

Adult C57BL/6 J male mice (8–10 weeks) were used to establish SAH models. The pharmacological agonist of SIRT3, Honokiol (HKL), was injected in an intraperitoneal manner (10 mg/kg) immediately after the operation. Brain edema and neurobehavioral score were assessed. Nissl staining and FJC staining were used to evaluate the extent of neuronal damage. The changes of mitochondria morphology were observed with transmission electron microscopy. Western blot was used for analyzing the protein level of SIRT3 and the downstream signaling molecules.

Result

SIRT3 was downregulated after SAH, and additional treatment of SIRT3 agonist HKL alleviated brain edema and neurobehavioral deficits after SAH. Additionally, electron microscopy showed that HKL significantly alleviated the morphological damage of mitochondria induced by SAH. Further studies showed that HKL could increase the level of mitochondrial fusion protein Mfn1 and Mfn2, thus maintaining (mitochondrial morphology), protecting mitochondrial function and promoting neural survival. While, additional Compound C (CC) treatment, a selective AMPK inhibitor, abolished these protective effects.

Conclusions

Activation of SIRT3 protects against SAH injury through improving mitochondrial fusion in an AMPK dependent manner.

Inflammatory Pathways Following Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is an acute cerebrovascular emergency resulting from the rupture of a brain aneurysm. Despite only accounting for 5% of all strokes, SAH imposes a significant health burden on society due to its relatively young age at onset. Those who survive the initial bleed are often afflicted with severe disabilities thought to result from delayed cerebral ischemia (DCI). Consequently, elucidating the underlying mechanistic pathways implicated in DCI development following SAH remains a priority. Neuroinflammation has recently been implicated as a promising new theory for the development of SAH complications. However, despite this interest, clinical trials have failed to provide consistent evidence for the use of anti-inflammatory agents in SAH patients. This may be explained by the complexity of SAH as a plethora of inflammatory pathways have been shown to be activated in the disease. By determining how these pathways may overlap and interact, we hope to better understand the developmental processes of SAH complications and how to prevent them. The goal of this review is to provide insight into the available evidence regarding the molecular pathways involved in the development of inflammation following SAH and how SAH complications may arise as a result of these inflammatory pathways.

Trehalose protects against spinal cord injury through regulating heat shock proteins 27 and 70 and caspase-3 genes expression

Background Heat shock proteins (HSPs) are a class of highly conserved proteins responsible for various functions critical to cell survival. Pharmacological induction of HSPs has been implicated in the regulation of neuronal loss and functional deficits in peripheral and central nervous system injuries. Accordingly, the present study was conducted to investigate the effect of trehalose on spinal expression of HSP27, HSP70 and caspase-3 genes following traumatic spinal cord injury (SCI) in rats. Methods Male rats weighing 250-300 g underwent laminectomy and were divided into four groups including sham, SCI (received SCI), vehicle (received SCI and phosphate buffer saline intrathecally) and trehalose (received 10 mM trehalose intrathecally following SCI). On days 1, 3 and 7 after injury, HSP27, HSP70 and caspase-3 genes transcripts were quantified in spinal cord tissues via a real-time PCR technique. In addition, locomotor function was assessed using the Basso, Beattie and Bresnahan (BBB) rating scale. Results SCI induced the expression of HSP27, HSP70 and caspase-3 genes and BBB score at all time points. Trehalose treatment upregulated HSP27, HSP70 genes expression at 1 day after SCI. Interestingly, a significant reduction in the expression of HSP27 and HSP70 genes was observed on days 3 and 7 following trauma compared with the vehicle group (p < 0.01). Caspase-3 gene showed a decrease in expression in the trehalose-treated group at all times. In addition, neurological function revealed an improvement after treatment with trehalose. Conclusion This study suggests that the neuroprotective effect of trehalose is mediated via regulation of HSP27 and HSP70, which are involved in cytoprotection and functional recovery following SCI.

Trehalose augments autophagy to mitigate stress induced inflammation in human corneal cells

PURPOSE

Cornea acts as a structural barrier and protects the eye from environmental stresses. Inflammation in ocular surface causes discomfort and visual distortion. Defective autophagy has been associated with inflammation and ocular surface diseases. Therefore, we explored the protective role of trehalose on inflammation and desiccation-triggered stress in human corneal cells in vitro and in dry eye patients.

METHOD

TNF-α and desiccation stress induced human corneal cells (piHCF and HCE-T) with or without trehalose treatment were analyzed for the expression levels of inflammatory and autophagy related markers by qPCR, western blotting, multiplex ELISA and fluorescence imaging. Dry eye patients (N = 9) were enrolled and administered with trehalose in one eye and carboxymethylcellulose (CMC) in the contralateral eye (B.I.D, for 30 days). Dry eye signs OSDI, TBUT, Schirmer's Test, and tear cytokines were measured in dry eye patient's pre and post treatment.

RESULTS

Cells treated with trehalose exhibits increased levels of autophagy markers LC3II and LAMP1 compared to untreated cells. Trehalose reduced the mRNA and secreted cytokines levels of IL-6, IL-8 and MCP-1 in corneal cells under TNF-α and desiccation stress mediated inflammation compared to controls. Further, trehalose reduced stress driven p38 phosphorylation in corneal cells. Additionally, topical administration of trehalose alleviated the clinical symptoms and tears cytokine levels in dry eye patients compared to CMC.

CONCLUSION

Trehalose reduces stress induced inflammation through p38MAPK inhibition and autophagy activation. The anti-inflammatory mechanism of trehalose was independent to NFκB pathway. Further, topical administration of trehalose ameliorated dry eye associated symptoms and associated tear cytokines levels.

Trehalose attenuates spinal cord injury through the regulation of oxidative stress, inflammation and GFAP expression in rats

OBJECTIVE

Inflammation and oxidative stress are implicated in pathogenesis of spinal cord injury (SCI). Trehalose, a nonreducing disaccharide, exhibits anti-inflammatory and antioxidant effects. The present study investigated the therapeutic efficacy of trehalose in the SCI model.

DESIGN AND SETTING

An experimental study was designed using 120 male Wistar rats which were randomly divided into three groups including SCI, SCI + phosphate buffer saline (vehicle) and SCI + trehalose. All rats were subjected to SCI. Immediately after SCI, vehicle and trehalose groups received intrathecal injection of buffer and trehalose, respectively.

OUTCOME MEASURES

The level of tissue TNFα, IL-1β, nitric oxide, malondialdehyde, myeloperoxidase, glial fibrillary acidic protein (GFAP) as well as hindlimb function were assessed at 4 hours, 1, 3 and 7 days post-SCI.

RESULTS

Data indicated an early significant decrease in inflammatory and oxidative responses following SCI in trehalose treated group. Moreover, trehalose reduced GFAP expression as soon as 1-day post-trauma. Furthermore, trehalose treatment increased the score of hindlimb function.

CONCLUSION

Our results indicated that treatment with trehalose reduces the development of secondary injury associated with SCI. This effect likely underlies improved neurological function.

Molecular mechanisms of trehalose in modulating glucose homeostasis in diabetes

Diabetes mellitus is the most prevalent metabolic disorder contributing to significant morbidity and mortality in humans. Many preventative and therapeutic agents have been developed for normalizing glycemic profile in patients with diabetes. In addition to various pharmacologic strategies, many non-pharmacological agents have also been suggested to improve glycemic control in patients with diabetes. Trehalose is a naturally occurring disaccharide which is not synthesized in human but is widely used in food industries. Some studies have provided evidence indicating that it can potentially modulate glucose metabolism and help to stabilize glucose homeostasis in patients with diabetes. Studies have shown that trehalose can significantly modulate insulin sensitivity via at least 7 molecular pathways leading to better control of hyperglycemia. In the current study, we concluded about possible anti-hyperglycemic effects of trehalose suggesting trehalose as a potentially potent non-pharmacological agent for the management of diabetes.

Trehalose elevates brain zinc levels following controlled cortical impact in a mouse model of traumatic brain injury

Zinc (Zn) deficiency is a clinical consequence of brain injury that can result in neuropathological outcomes that are exacerbated with age. Here, we present laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging data showing modulation of brain Zn levels by the disaccharide trehalose in aged mice following a controlled cortical impact model of traumatic brain injury. In this proof-of-concept study, trehalose induced an increase in brain zinc levels, providing important preliminary data for larger studies using this simple carbohydrate as a modulator of this essential micronutrient in traumatic brain injury. Our results may have further implications for the treatment of a variety of neurodegenerative diseases and other disorders of the nervous system.

Trehalose as a promising therapeutic candidate for the treatment of Parkinson's disease

Parkinson's disease (PD) is a progressive movement disorder resulting primarily from loss of nigrostriatal dopaminergic neurons. PD is characterized by the accumulation of protein aggregates, and evidence suggests that aberrant protein deposition in dopaminergic neurons could be related to the dysregulation of the lysosomal autophagy pathway. The therapeutic potential of autophagy modulators has been reported in experimental models of PD. Trehalose is a natural disaccharide that has been considered as a new candidate for the treatment of neurodegenerative diseases. It has a chaperone-like activity, prevents protein misfolding or aggregation, and by promoting autophagy, contributes to the removal of accumulated proteins. In this review, we briefly summarize the role of aberrant autophagy in PD and the underlying mechanisms that lead to the development of this disease. We also discuss reports that used trehalose to counteract the neurotoxicity in PD, focusing particularly on the autophagy promoting, protein stabilization, and anti-neuroinflammatory effects of trehalose.

Beneficial Effects of Trehalose on Striatal Dopaminergic Deficits in Rodent and Primate Models of Synucleinopathy in Parkinson's Disease

Disease modification in Parkinson's disease (PD) is an unmet medical need. In the current study, we evaluated trehalose, a safe and well-tolerated disaccharide that has previously demonstrated efficacy in rodent models of neurodegenerative diseases, including PD. In a rat model of PD, based on delivery of adeno-associated virus serotype 1/2 containing the mutated human A53T α-synuclein gene (AAV1/2-hourA53T-aSyn) to the substantia nigra (SN), we showed that rats administered trehalose (2.67 g/kg per day, by mouth) for 6 weeks had less forelimb asymmetry (93% reduction) and higher striatal dopamine (54% increase) compared with rats receiving vehicle. In a pharmacokinetic study, we determined that efficacy was associated with plasma C _max of 8900 ng/ml and area under the curve from time 0 to infinity (AUC_0-inf) of 11,136 hour⋅ng/ml. We then showed, in macaques, that oral administration of trehalose (2.67 g/kg per day) produced plasma exposures of similar magnitude, with plasma C _max of 10,918 ng/ml and AUC_0-inf of 27,445 hour⋅ng/ml. In a macaque model of PD, also based on delivery of AAV1/2-hourA53T-aSyn to the SN, trehalose (2.67 g/kg per day, by mouth), administered for 142 days, produced higher striatal dopamine (by 39%) and dopamine transporter levels (by 50%), compared with macaques receiving vehicle. In neither model did trehalose treatment prevent loss of tyrosine hydroxylase (TH) positive (TH^+ve) cells in the SN or alter α-synuclein levels in the striatum. These studies demonstrated that trehalose reduces striatal dopaminergic deficits in a rodent and macaque model of synucleinopathy in PD. Furthermore, we have determined the pharmacokinetic parameters associated with efficacy, and thus defined exposures to target in future clinical trials.

Hookworm-Derived Metabolites Suppress Pathology in a Mouse Model of Colitis and Inhibit Secretion of Key Inflammatory Cytokines in Primary Human Leukocytes

Iatrogenic hookworm therapy shows promise for treating disorders that result from a dysregulated immune system, including inflammatory bowel disease (IBD). Using a murine model of trinitrobenzenesulfonic acid-induced colitis and human peripheral blood mononuclear cells, we demonstrated that low-molecular-weight metabolites derived from both somatic extracts (LMWM-SE) and excretory-secretory products (LMWM-ESP) of the hookworm, Ancylostoma caninum, display anti-inflammatory properties. Administration to mice of LMWM-ESP as well as sequentially extracted fractions of LMWM-SE using both methanol (SE-MeOH) and hexane-dichloromethane-acetonitrile (SE-HDA) resulted in significant protection against T cell-mediated immunopathology, clinical signs of colitis, and impaired histological colon architecture. To assess bioactivity in human cells, we stimulated primary human leukocytes with lipopolysaccharide in the presence of hookworm extracts and showed that SE-HDA suppressed ex vivo production of inflammatory cytokines. Gas chromatography-mass spectrometry (MS) and liquid chromatography-MS analyses revealed the presence of 46 polar metabolites, 22 fatty acids, and five short-chain fatty acids (SCFAs) in the LMWM-SE fraction and 29 polar metabolites, 13 fatty acids, and six SCFAs in the LMWM-ESP fraction. Several of these small metabolites, notably the SCFAs, have been previously reported to have anti-inflammatory properties in various disease settings, including IBD. This is the first report showing that hookworms secrete small molecules with both ex vivo and in vivo anti-inflammatory bioactivity, and this warrants further exploration as a novel approach to the development of anti-inflammatory drugs inspired by coevolution of gut-dwelling hookworms with their vertebrate hosts.

Modulation of Autophagy for Controlling Immunity

Autophagy is an essential process that maintains physiological homeostasis by promoting the transfer of cytoplasmic constituents to autophagolysosomes for degradation. In immune cells, the autophagy pathway plays an additional role in facilitating proper immunological functions. Specifically, the autophagy pathway can participate in controlling key steps in innate and adaptive immunity. Accordingly, alterations in autophagy have been linked to inflammatory diseases and defective immune responses against pathogens. In this review, we discuss the various roles of autophagy signaling in coordinating immune responses and how these activities are connected to pathological conditions. We highlight the therapeutic potential of autophagy modulators that can impact immune responses and the mechanisms of action responsible.

Modulating Effect of Diet on Alzheimer's Disease

As life expectancy is growing, neurodegenerative disorders, such as Alzheimer's disease, are increasing. This disease is characterised by the accumulation of intracellular neurofibrillary tangles formed by hyperphosphorylated tau protein, senile plaques composed of an extracellular deposit of β-amyloid peptide (Aβ), and neuronal loss. This is accompanied by deficient mitochondrial function, increased oxidative stress, altered inflammatory response, and autophagy process impairment. The present study gathers scientific evidence that demonstrates that specific nutrients exert a direct effect on both Aβ production and Tau processing and their elimination by autophagy activation. Likewise, certain nutrients can modulate the inflammatory response and the oxidative stress related to the disease. However, the extent to which these effects come with beneficial clinical outcomes remains unclear. Even so, several studies have shown the benefits of the Mediterranean diet on Alzheimer's disease, due to its richness in many of these compounds, to which can be attributed their neuroprotective properties due to the pleiotropic effect they show on the aforementioned processes. These indications highlight the potential role of adequate dietary recommendations for clinical management of both Alzheimer's diagnosed patients and those in risk of developing it, emphasising once again the importance of diet on health.