Astragaloside IV alleviates macrophage senescence and d-galactose-induced bone loss in mice through STING/NF-κB pathway

BACKGROUND

Senile osteoporosis (SOP) is an age-related metabolic bone disease that currently lacks specific therapeutic interventions. Thus, this study aimed to investigate the effect of Astragaloside IV (AS-IV) on macrophage senescence, bone marrow mesenchymal stem cell (BMSC) osteogenesis, and SOP progression.

METHODS

A senescent macrophage model was established and treated with varying concentrations of AS-IV. Cell activity was measured using the CCK8 assay. The senescence levels of macrophages were evaluated through β-galactosidase staining, PCR, and immunofluorescence. Macrophage mitochondrial function was assessed using ROS and JC-1 staining. Macrophage polarization was evaluated through PCR, Western blot, and immunofluorescence. The inhibitory effects of AS-IV on macrophage senescence were investigated using Western blot analysis. Furthermore, the effects of macrophage conditioned medium (CM) on BMSCs osteogenic were detected using ALP, alizarin red, and PCR.

RESULTS

AS-IV inhibited macrophage senescence and M1 polarization, alleviated mitochondrial dysfunction, and promoted M2 polarization. Mechanistically, it suppressed the STING/NF-κB pathway in H2O2-activated macrophages. Conversely, the STING agonist c-di-GMP reversed the effects of AS-IV on macrophage senescence. Additionally, AS-IV-induced macrophage CM promoted BMSC osteogenic differentiation. In vivo, AS-IV treatment ameliorated aberrant bone microstructure and bone mass loss in the SOP mouse model, inhibited macrophage senescence, and promoted M2 polarization.

CONCLUSIONS

By modulating the STING/NF-κB signaling pathway, AS-IV potentially inhibited macrophage senescence and stimulated osteogenic differentiation of BMSCs, thus exerting an anti-osteoporotic effect. Consequently, AS-IV may serve as an effective therapeutic candidate for the treatment of osteoporosis.

Carrier-free self-assembled nanomedicine based on celastrol and galactose for targeting therapy of hepatocellular carcinoma via inducing ferroptosis

Triggering ferroptosis is a potential therapeutic pathway and strategy for the prospective treatment of lethal hepatocellular carcinoma (HCC). The asialo-glycoprotein receptor (ASGPR) is an over-expressed receptor on the membranes of hepatocellular carcinoma cells (HCCs) and binds specifically to galactose (Gal) ligand. Celastrol (CE) is a potent anticancer natural product, but its poor water solubility and severe toxicity restrict its clinical application. In this study, a carrier-free self-assembled nanoparticles, CE-Gal-NPs, were designed and prepared by nanoprecipitation method, which could recognize ASGPR receptor by active targeting (Gal ligand) and passive targeting (EPR effect), access to the cell through the clathrin pathway and finally internalize to lysosomes. CE-Gal-NPs triggered reactive oxygen species (ROS)-mediated ferroptosis pathway and exerted anti-HCC effects in vitro and in vivo by down-regulating GPX4 and up-regulating COX-2 expression, depleting glutathione (GSH) levels, and increasing lipid peroxidation levels in cells and tumor tissues. In the H22 xenograft mouse model, the CE-Gal-NPs group exhibited dramatically superior tumor inhibition than the CE group, while Gal conjugating diminished the systemic toxicity of CE. Consequently, this study presented a promising strategy for CE potentiation and toxicity reduction, as well as a potential guideline for the development of clinically targeted therapeutic agents for HCC.

Use of antithymocyte globulin (rabbit) in a patient with known alpha-gal syndrome undergoing allogenic stem cell transplantation

INTRODUCTION

Alpha-gal syndrome (AGS) is a hypersensitivity disorder in which tick bites-most commonly from the lone star tick (Ambylomma americanum)-trigger immunoglobulin E-mediated hypersensitivity reaction upon exposure to oligosaccharide galactosse-alpha-1,3-galactose (α-gal). α-gal is most notorious for being found in "red meat" products but is present in mammalian meats such as beef, pork, lamb, rabbit, and others. Manifestations of AGS hypersensitivity are variable. There is currently no in vivo data describing allergic reactions against rabbit products in patients with AGS.

CASE REPORT

Here, we describe a case of a 44-year-old male with myelodysplastic syndrome and a known history of AGS undergoing allogeneic hematopoietic cell transplantation (allo-HSCT) with the use of rabbit antithymocyte globulin (rATG) for graft-versus-host disease (GVHD) prophylaxis.

MANAGEMENT AND OUTCOME

The risk of cross-reactivity against rATG in our patient with AGS could not be ruled out and, therefore, a test dose was administered. The patient tolerated the test dose with no signs of anaphylaxis. After demonstrating tolerance to the test dose, rATG was utilized for GVHD prophylaxis.

DISCUSSION

Due to the heterogeneity of AGS manifestations in patients, the use of rATG in patients with known AGS should be considered on a case-by-case basis. The administration of a test dose may help predict the occurrence of severe hypersensitivity reactions. The limited data surrounding the risk of AGS with rabbit-containing products and the various indications for the use of rATG warrants more in-depth study of the reactivity of this medication in this population.

Metformin improves d-galactose induced premature ovarian insufficiency through PI3K-Akt-FOXO3a pathway

PURPOSE

Metformin (MET), a first-line treatment for type 2 diabetes mellitus, restores ovarian function in women with polycystic ovary syndrome. MET has been shown to increase the rate of success for in vitro fertilization when utilized in assisted reproductive technologies. This study was designed to examine the impact of MET on ovarian function and fertility in a mouse model of galactose-induced premature ovarian insufficiency (POI). We further investigated the underlying mechanisms.

MATERIALS AND METHODS

Female mice were divided into 4 groups: saline, d-galactose, d-galactose ​+ ​MET, and MET. Body weight, ovarian index, and fertility were assessed. The hormonal profile was done. Advanced glycation end products (AGEPs), receptor for advanced glycation end products (RAGE), phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), forkhead box O3a (FOXO3a) expression were measured. Ovarian follicle counting and morphology were analyzed. Immunohistochemistry of cleaved caspase-3 expression was performed.

RESULTS

Our findings demonstrated that MET reversed irregularities in the estrus cycle, enhanced the ovarian index, and improved the abnormal levels of hormones and AGEs induced by d-galactose. Furthermore, the expression levels of PI3K, Akt, FOXO3a, and RAGE were upregulated with d-galactose. However, MET attenuated their expression levels. The primordial follicles ratio was improved, whereas atretic follicles and apoptotic-related cleaved caspase-3 expression were decreased in the d-galactose ​+ ​MET group compared to the d-galactose group.

CONCLUSION

This study demonstrates that MET partially rescued ovarian dysfunction and apoptosis induced by d-galactose via a mechanism involving PI3K-Akt-FOXO3a pathway. Our finding proposed that MET may be a promising alternative treatment for POI.

Cell wall as a barrier for protein extraction from tomato leaves: A biochemical study

Solanum lycopersicum (Tomato) leaves and stems are considered waste. Valorization of this waste can be achieved by for example the extraction of proteins. This prospect is promising but currently not feasible, since protein extraction yields from tomato leaves are low, amongst other due to the (physical) barrier formed by the plant cell walls. However, the molecular aspects of the relationship between cell wall properties and protein extractability from tomato leaves are currently not clear and thus objective of this study. To fill this knowledge gap the biochemical composition of plant cell walls was measured and related to protein extraction yields at different plant ages, leaf positions, and across different tomato accessions, including two Solanum lycopersicum cultivars and the wildtype species S. pimpinellifolium and S. pennellii. For all genotypes, protein extraction yields from tomato leaves were the highest in young tissues, with a decreasing trend towards older plant material. This decrease of protein extraction yield was accompanied by a significant increase of arabinose and galacturonic acid content and a decrease of galactose content in the cell walls of old-vs-young tissues. This resulted in strong negative correlations between protein extraction yield and the content of arabinose and galacturonic acid in the cell wall, and a positive correlation between the content of galactose and protein extraction yield. Overall, these results point to the importance of the pectin network on protein extractability, making pectin a potential breeding target for enhancing protein extractability from tomato leaves.

Gene-edited pigs: a translational model for human food allergy against alpha-Gal and anaphylaxis

The prevalence of food allergy is rising and is estimated to approach 10%. Red meat allergy is the first known food allergy elicited by immunoglobulin E (IgE) antibodies recognizing a carbohydrate. Due to the loss of function of the alpha-1,3-galactosyltransferase (GGTA1) gene in humans, the disaccharide galactose-α-1,3-galactose (α-Gal) cannot be synthesized and therefore became immunogenic. IgE sensitization is elicited through the skin by repetitive tick bites transmitting α-Gal. The underlying mechanisms regarding innate and adaptive immune cell activation, including the B-cell isotype switch to IgE, are poorly understood, requiring further research and physiologically relevant animal models. Here, we describe a new animal model of red meat allergy using percutaneous α-Gal sensitization of gene-edited GGTA1-deficient pigs. Total and α-Gal-specific IgG, IgG1, IgG2, IgG4, and IgE levels were tracked. Further key factors associated with allergic skin inflammation, type 2 immunity, and allergy development were measured in PBMCs and skin samples. Significant increases in α-Gal-specific IgG1 and IgE levels indicated successful sensitization to the allergen α-Gal. Intracutaneous sensitizations with α-Gal recruited lymphocytes to the skin, including elevated numbers of T helper 2 (Th2) cells. Finally, α-Gal-sensitized pigs not only recognized α-Gal as non-self-antigen following α-Gal exposure through the skin but also developed anaphylaxis upon antigen challenge. Based on the similarities between the porcine and human skin, this new large animal model for α-Gal allergy should help to unveil the consecutive steps of cutaneous sensitization and aid the development of prophylactic and treatment interventions.

The use of multicomponent reactions in the development of bis-boronic acids for the detection of β-sialic acid

Sialic acid (SA) is a naturally occurring monosaccharide found in glycoproteins and glycolipids. Changes in the expression of SA are associated with several diseases; thus, the detection of SA is of great significance for biological research, cancer diagnosis, and treatment. Boronic acid analogs have emerged as a promising tool for detecting sugars such as SA due to its reversible covalent bonding ability. In this study, 11 bis-boronic acid compounds and 2 mono-boronic acid compounds were synthesized via a highly efficient Ugi-4CR strategy. The synthesized compounds were subjected to affinity fluorescence binding experiments to evaluate their binding capability to SA. Compound A1 was shown to have a promising binding constant of 2602 ± 100 M-1 at pH = 6.0. Density Functional Theory (DFT) calculations examining the binding modes between A1 and SA indicated that the position of the boronic acid functional group was strongly correlated with its interaction with SA's α-hydroxy acid unit. The DFT calculations were consistent with the observations from the fluorescence experiments, demonstrating that the number and relative positions of the boronic acid functional groups are critical factors in enhancing the binding affinity to SA. DFT calculations of both S and R configuration of A1 indicated that the effect of the S/R configuration of A1 on its binding with β-sialic acid was insignificant as the Ugi-4CR generated racemic products. A fluorine atom was incorporated into the R2 substituent of A1 as an electron-withdrawing group to produce A5, which possessed a significantly higher capability to bind to SA (Keq = 7015 ± 5 M-1 at pH = 6.0). Finally, A1 and A5 were shown to possess exceptional binding selectivity toward β-sialic acid under pH of 6.0 and 6.5 while preferring to bind with glucose, fructose, and galactose under pH of 7.0 and 7.5.

Efficient One-Pot Synthesis of Uridine Diphosphate Galactose Employing a Trienzyme System

The limited availability of high-cost nucleotide sugars is a significant constraint on the application of their downstream products (glycosides and prebiotics) in the food or pharmaceutical industry. To better solve the problem, this study presented a one-pot approach for the biosynthesis of UDP-Gal using a thermophilic multienzyme system consisting of GalK, UGPase, and PPase. Under optimal conditions, a 2 h reaction resulted in a UTP conversion rate of 87.4%. In a fed-batch reaction with Gal/ATP = 20 mM:10 mM, UDP-Gal accumulated to 33.76 mM with a space-time yield (STY) of 6.36 g/L·h-1 after the second feeding. In repetitive batch synthesis, the average yield of UDP-Gal over 8 cycles reached 10.80 g/L with a very low biocatalyst loading of 0.002 genzymes/gproduct. Interestingly, Galk (Tth0595) could synthesize Gal-1P using ADP as a donor of phosphate groups, which had never been reported before. This approach possessed the benefits of high synthesis efficiency, low cost, and superior reaction system stability, and it provided new insights into the rapid one-pot synthesis of UDP-Gal and high-value glycosidic compounds.

Synthesis of a fluorescent probe for measuring the activity of endo-β-N-acetylglucosaminidases recognizing hybrid-type N-glycans

A fluorescence-quenching-based assay system was constructed to determine the hydrolytic activity of endo-β-N-acetylglucosaminidases (ENGases) interacting with hybrid-type N-glycans. This was achieved using a dual-labeled fluorescent probe with a nonasaccharide structure. We produced the nonasaccharide skeleton by the stepwise glycosylation of the galactose residue on a galactosyl chitobiose derivative. Next, we introduced azido and acetoxy groups into the nonasaccharide derivative in a stepwise manner, which led to stereochemistry inversion at both the C-4 and C-2 hydroxy groups on its galactose residue. The protecting groups of the resulting nonasaccharide derivative were removed, and the derivative was labeled with an N-methylanthraniloyl group to obtain a reporter dye and a 2,4-dinitrophenyl group as a quenching molecule to obtain target probe 1. The use of this probe along with a microplate reader enabled a facile evaluation of the hydrolytic activities of ENGases Endo-H, Endo-M, Endo-F3, Endo-S, and Endo-CC. Furthermore, this probe could also assist in the search for novel ENGases that are specific to hybrid-type N-glycans.

Management of Food Allergies and Food-Related Anaphylaxis

Importance

An estimated 7.6% of children and 10.8% of adults have IgE-mediated food-protein allergies in the US. IgE-mediated food allergies may cause anaphylaxis and death. A delayed, IgE-mediated allergic response to the food-carbohydrate galactose-α-1,3-galactose (alpha-gal) in mammalian meat affects an estimated 96 000 to 450 000 individuals in the US and is currently a leading cause of food-related anaphylaxis in adults.

Observations

In the US, 9 foods account for more than 90% of IgE-mediated food allergies-crustacean shellfish, dairy, peanut, tree nuts, fin fish, egg, wheat, soy, and sesame. Peanut is the leading food-related cause of fatal and near-fatal anaphylaxis in the US, followed by tree nuts and shellfish. The fatality rate from anaphylaxis due to food in the US is estimated to be 0.04 per million per year. Alpha-gal syndrome, which is associated with tick bites, is a rising cause of IgE-mediated food anaphylaxis. The seroprevalence of sensitization to alpha-gal ranges from 20% to 31% in the southeastern US. Self-injectable epinephrine is the first-line treatment for food-related anaphylaxis. The cornerstone of IgE-food allergy management is avoidance of the culprit food allergen. There are emerging immunotherapies to desensitize to one or more foods, with one current US Food and Drug Administration-approved oral immunotherapy product for treatment of peanut allergy.

Conclusions and Relevance

IgE-mediated food allergies, including delayed IgE-mediated allergic responses to red meat in alpha-gal syndrome, are common in the US, and may cause anaphylaxis and rarely, death. IgE-mediated anaphylaxis to food requires prompt treatment with epinephrine injection. Both food-protein allergy and alpha-gal syndrome management require avoiding allergenic foods, whereas alpha-gal syndrome also requires avoiding tick bites.

Structure and Binding Properties to Blood Co-Factors of the Least Sulfated Galactan Found in the Cell Wall of the Red Alga Botryocladia occidentalis

Three different populations of sulfated polysaccharides can be found in the cell wall of the red alga Botryocladia occidentalis. In a previous work, the structures of the two more sulfated polysaccharides were revised. In this work, NMR-based structural analysis was performed on the least sulfated polysaccharide and its chemically modified derivatives. Results have revealed the presence of both 4-linked α- and 3-linked β-galactose units having the following chemical features: more than half of the total galactose units are not sulfated, the α-units occur primarily as 3,6-anhydrogalactose units either 2-O-methylated or 2-O-sulfated, and the β-galactose units can be 4-O-sulfated or 2,4-O-disulfated. SPR-based results indicated weaker binding of the least sulfated galactan to thrombin, factor Xa, and antithrombin, but stronger binding to heparin cofactor II than unfractionated heparin. This report together with our previous publication completes the structural characterization of the three polysaccharides found in the cell wall of the red alga B. occidentalis and correlates the impact of their composing chemical groups with the levels of interaction with the blood co-factors.

Tick bite-induced alpha-gal syndrome and immunologic responses in an alpha-gal deficient murine model

Introduction

Alpha-Gal Syndrome (AGS) is a delayed allergic reaction due to specific IgE antibodies targeting galactose-α-1,3-galactose (α-gal), a carbohydrate found in red meat. This condition has gained significant attention globally due to its increasing prevalence, with more than 450,000 cases estimated just in the United States alone. Previous research has established a connection between AGS and tick bites, which sensitize individuals to α-gal antigens and elevate the levels of specific IgE. However, the precise mechanism by which tick bites influence the host's immune system and contribute to the development of AGS remains poorly understood. This study investigates various factors related to ticks and the host associated with the development of AGS following a tick bite, using mice with a targeted disruption of alpha-1,3-galactosyltransferase (AGKO) as a model organism.

Methods

Lone-star tick (Amblyomma americanum) and gulf-coast tick (Amblyomma maculatum) nymphs were used to sensitize AGKO mice, followed by pork meat challenge. Tick bite site biopsies from sensitized and non-sensitized mice were subjected to mRNA gene expression analysis to assess the host immune response. Antibody responses in sensitized mice were also determined.

Results

Our results showed a significant increase in the total IgE, IgG1, and α-gal IgG1 antibodies titers in the lone-star tick-sensitized AGKO mice compared to the gulf-coast tick-sensitized mice. Pork challenge in Am. americanum -sensitized mice led to a decline in body temperature after the meat challenge. Gene expression analysis revealed that Am. americanum bites direct mouse immunity toward Th2 and facilitate host sensitization to the α-gal antigen.

Conclusion

This study supports the hypothesis that specific tick species may increase the risk of developing α-gal-specific IgE and hypersensitivity reactions or AGS, thereby providing opportunities for future research on the mechanistic role of tick and host-related factors in AGS development.

IgE to common food allergens is associated with cardiovascular mortality in the National Health and Examination Survey and the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

In individuals without symptomatic food allergy, food-specific IgE is considered clinically irrelevant. However, recent studies have suggested that galactose-α-1,3-galactose (alpha-gal) IgE is associated with cardiovascular (CV) disease.

OBJECTIVE

We sought to determine whether sensitization to common food allergens is associated with CV mortality.

METHODS

The association between IgE sensitization to foods and CV mortality ascertained to 2019 was examined in the National Health and Examination Survey (NHANES) 2005-2006 and the Wake Forest site of the Multi-Ethnic Study of Atherosclerosis (MESA) cohort; MESA enrolled adults without baseline clinical CV diseases between 2000 and 2002. Total and specific IgE was measured to cow's milk, egg, peanut, shrimp, and a panel of aeroallergens (NHANES), and to cow's milk, alpha-gal, peanut, dust mite, and timothy grass (MESA). Cox proportional hazard models were constructed, adjusting for sex, age, race/ethnicity, smoking, education, and asthma.

RESULTS

A total of 4414 adults from NHANES (229 CV deaths) and 960 from MESA (56 CV deaths) were included. In NHANES, sensitization to at least 1 food was associated with higher CV mortality (hazard ratio [HR], 1.7 [95% confidence interval (CI), 1.2-2.4], P = .005). Milk sensitization was particularly associated (HR, 2.0 [95% CI, 1.1-3.8], P = .026), a finding replicated in MESA (HR, 3.8 [95% CI, 1.6-9.1], P = .003). Restricting analyses in NHANES to consumers of the relevant allergen strengthened food sensitization relationships, unmasking shrimp and peanut sensitization as additional risk factors for CV mortality.

CONCLUSIONS

The finding that food sensitization is associated with increased risk of CV mortality challenges the current paradigm that sensitization without overt allergy is benign. Further research is needed to clarify mechanisms of this association.

Sulfated Galactofucan from Sargassum Thunbergii Attenuates Atherosclerosis by Suppressing Inflammation Via the TLR4/MyD88/NF-κB Signaling Pathway

PURPOSE

Sulfated galactofucan (SWZ-4), which was extracted from Sargassum thunbergii, has recently been reported to show anti-inflammatory and anticancer properties. The present study aimed to evaluate whether SWZ-4 attenuates atherosclerosis in apolipoprotein E-knockout (ApoE-KO) mice by suppressing the inflammatory response through the TLR4/MyD88/NF-κB signaling pathway.

METHODS

Male ApoE-KO mice were fed with a high-fat diet for 16 weeks and intraperitoneally injected with SWZ-4. RAW246.7 cells were treated with lipopolysaccharide (LPS) and SWZ-4. Atherosclerotic lesions were measured by Sudan IV and oil red O staining. Serum lipid profiles, inflammatory cytokines, and mRNA and protein expression levels were evaluated.

RESULTS

SWZ-4 decreased serum TNF-α, IL-6 and IL-1 levels, but did not reduce blood lipid profiles. SWZ-4 downregulated the mRNA and protein expression of TLR4 and MyD88, reduced the phosphorylation of p65, and attenuated atherosclerosis in the ApoE-KO mice (p < 0.01). In LPS-stimulated RAW 264.7 cells, SWZ-4 inhibited proinflammatory cytokine production and the mRNA expression of TLR4, MyD88, and p65 and reduced the protein expression of TLR4 and MyD88 and the phosphorylation of p65 (p < 0.01).

CONCLUSION

These results suggest that SWZ-4 may exert an anti-inflammatory effect on ApoE-KO atherosclerotic mice by inhibiting the TLR4/MyD88/NF-κB signaling pathway in macrophages and therefore may be a treatment for atherosclerosis.

Dietary Intake of Fructooligosaccharides Protects against Metabolic Derangements Evoked by Chronic Exposure to Fructose or Galactose in Rats

SCOPE

Diets rich in fat and sugars evoke chronic low-grade inflammation, leading to metabolic derangements. This study investigates the impact of fructose and galactose, two commonly consumed simple sugars, on exacerbation of the harmful effects caused by high fat intake. Additionally, the potential efficacy of fructooligosaccharides (FOS), a fermentable dietary fiber, in counteracting these effects is examined.

METHODS AND RESULTS

Male Sprague-Dawley rats (six/group) are fed 8 weeks as follows: control 5% fat diet (CNT), 20% fat diet (FAT), FAT+10% FOS diet (FAT+FOS), FAT+25% galactose diet (FAT+GAL), FAT+GAL+10% FOS diet (FAT+GAL+FOS), FAT+25% fructose diet (FAT+FRU), FAT+FRU+10% FOS diet (FAT+FRU+FOS). The dietary manipulations tested do not affect body weight gain, blood glucose, or markers of systemic inflammation whereas significant increases in plasma concentrations of triacylglycerols, cholesterol, aspartate aminotransferase, and alanine aminotrasferase are detected in both FAT+FRU and FAT+GAL compared to CNT. In the liver and skeletal muscle, both sugars induce significant accumulation of lipids and advanced glycation end-products (AGEs). FOS supplementation prevents these impairments.

CONCLUSION

This study extends the understanding of the deleterious effects of a chronic intake of simple sugars and demonstrates the beneficial role of the prebiotic FOS in dampening the sugar-induced metabolic impairments by prevention of lipid and AGEs accumulation.

Sialylation status and its relationship with morphofunctional changes in human adult testis during sexually mature life and aging: A narrative review

Sialic acids (Sias) are a family of electronegatively charged nine-carbon monosaccharides containing a carboxylic acid, mostly found as terminal residues in glycans of glycoproteins and glycolipids. They are bound to galactose or N-acetylgalactosamine via α2,3 or α2,6 linkage, or to other Sias especially via α2,8 linkage, which results in monomeric, oligomeric, and polymeric forms. Sias play determinant roles in a multitude of biological processes in human tissues from development to adult life until aging. In this review, we summarized the current knowledge on the sialylation status in the human testis with a main focus on sexually mature life and aging, when this organ shows significant morphofunctional changes resulting into variations of hormonal levels, as well as changes in molecules involved in mitochondrial function, receptors, and signaling proteins. Evidence suggests that Sias may have crucial morphofunctional roles in the different testicular components during the sexually mature age. With advancing age, significant loss of Sias and/or changes in sialylation status occur in all the testicular components, which seems to contribute to morphofunctional changes characteristic of the aging testis. Based on the current knowledge, further in-depth investigations will be necessary to better understand the mechanistic role of Sias in the biological processes of human testicular tissue and the significance of their changes during the aging process. Future investigations might also contribute to the development of novel prophylactic and/or therapeutic approaches that, by maintaining/restoring the correct sialylation status, could help in slowing down the testis aging process, thus preserving the testicular structure and functionality and preventing age-related pathologies.

Label-Free Liquid Chromatography-Mass Spectrometry Quantitation of Relative N- and O-Glycan Concentrations in Human Milk in Japan

Human milk is abundant in carbohydrates and includes human milk oligosaccharides (HMOs) and N/O-glycans conjugated to proteins. HMO compositions and concentrations vary in individuals according to the maternal secretor status based on the fucosyltransferase 2 genotype; however, the profile of N/O-glycans remains uninvestigated because of the analytical complexity. Herein, we applied a label-free chromatography-mass spectrometry (LC-MS) technique to elucidate the variation in the composition and concentration of N/O-glycans in human milk. We used label-free LC-MS to relatively quantify 16 N-glycans and 12 O-glycans in 200 samples of Japanese human milk (1-2 months postpartum) and applied high performance anion exchange chromatography with pulsed amperometric detection to absolutely quantify the concentrations of 11 representative HMOs. Cluster analysis of the quantitative data revealed that O-glycans and several HMOs were classified according to the presence or absence of fucose linked to galactose while N-glycans were classified into a different group from O-glycans and HMOs. O-glycans and HMOs with fucose linked to galactose were more abundant in human milk from secretor mothers than from nonsecretor mothers. Thus, secretor status influenced the composition and concentration of HMOs and O-glycans but not those of N-glycans in human milk.

Structural properties and biological activities of the extracellular polysaccharide of Bacillus subtilis LZ13-4

The remarkable functional characteristics of Bacillus subtilis extracellular polysaccharides (BSPS) are of great interest. Therefore, in the present study, BSPS was isolated and characterized to obtain two fractions, BSPS-1 and BSPS-2, respectively, and to investigate their biological activities. BSPS-1 contained fructose, glucose, and galactose (molar ratio: 25.27:43.37:31.36), while BSPS-2 contained fructose with only trace amounts of glucose, galactose, and mannose (molar ratio: 55.08:19.03:19.21:6.68), and their respective average molecular weights were 16.9 kDa and 202.67 kDa. With a 93.55 % clearance of ABTS•+ at a concentration of 2 mg/mL of BSPS-1, the antioxidant activity revealed that BSPS-1 had greater antioxidant activity than BSPS-2 and that both were concentration-dependent. The inhibitory effect on HepG2 cells demonstrated that BSPS-1 and BSPS-2 significantly inhibited the proliferation of HepG2 and increased the expression of apoptotic proteins, causing apoptosis. The inhibition rate on HepG2 cells was dose-dependent and reached 52.7 % and 40.3 % after 48 h of action. BSPS-2 and 800 μg/mL BSPS-1 growth was inhibited in the G1/G0 phase, while 200 and 400 μg/mL BSPS-1 growth was inhibited in the S phase. In conclusion, the study of the BSPS's structure and properties can offer a theoretical foundation for real-world industrial applications.

Lactase can target cellular differentiation of Acanthamoeba castellanii belonging to the T4 genotype

The free living Acanthamoeba spp. are ubiquitous amoebae associated with potentially blinding disease known as Acanthamoeba keratitis (AK) and a fatal central nervous system infection granulomatous amoebic encephalitis (GAE). With the inherent ability of cellular differentiation, it can phenotypically transform to a dormant cyst form from an active trophozoite form. Acanthamoeba cysts are highly resistant to therapeutic agents as well as contact lens cleaning solutions. One way to tackle drug resistance against Acanthamoeba is by inhibiting the formation of cysts from trophozoites. The biochemical analysis showed that the major component of Acanthamoeba cyst wall is composed of carbohydrate moieties such as galactose and glucose. The disaccharide of galactose and glucose is lactose. In this study, we analyzed the potential of lactase enzyme to target carbohydrate moieties of cyst walls. Amoebicidal assessment showed that lactase was ineffective against trophozoite of A. castellanii but enhanced amoebicidal effects of chlorhexidine. The lactase enzyme did not show any toxicity against normal human keratinocyte cells (HaCaT) at the tested range. Hence, lactase can be used for further assessment for development of potential therapeutic agents in the management of Acanthamoeba infection as well as formulation of effective contact lens disinfectants.

False-positive results of galactomannan assays in patients administered glucose-containing solutions

Galactomannan (GM) is a polysaccharide cell wall component released by Aspergillus spp., and an immunoenzymatic GM assay is used for the diagnosis of invasive pulmonary aspergillosis. We evaluated the cause of strong positivity for GM in patients with no typical signs of aspergillosis. Repeat assays were performed using different instruments and reagent lots, but there were no differences in results among the assays. Patients with strongly positive GM results were investigated. Medication histories revealed that 14 of 23 patients had been administered total parenteral nutrition solution from one manufacturer and 4 patients had been administered dextrose solution from a different manufacturer before being tested. The results of GM assays conducted on samples of dextrose solution and the glucose fraction of the total parenteral nutrition solution were strongly positive, confirming the causes of the false-positive reactions. We hypothesize that a trace amount of GM was introduced into the glucose-containing solutions because glucoamylase, which is necessary for the saccharification step of glucose synthesis, was derived from Aspergillus niger. To enhance patient care and prevent unnecessary antifungal prescriptions, healthcare providers and manufacturers of healthcare products need to be aware of the possibility of false-positive reactions for GM.

The decrease of Ara h 2 allergenicity by glycation is determined by reducing sugar chain length and isomers

The mechanism of the effect of reducing sugar chain length and isomers on the allergenicity of Ara h 2 after glycation was investigated. Ara h 2 was more prone to glycation with ribose which had a short chain length. The glycation sites of Ara h 2 after glycation with galactose were higher than the glycation sites in galactose's isomers-Ara h 2 conjugates, which might be affected by the configuration differences at position C-4 and the small steric effects in terminal groups -CHO of galactose. Ara h 2-ribose conjugate had the lowest allergenicity, and glycation with galactose was more capable of reducing Ara h 2 allergenicity than its isomers. The results indicated that glycation with ribose caused conformational epitope destruction and linear epitope masking of Ara h 2 greatly. Furthermore, since the small steric effects of -CHO, galactose was more capable of reducing Ara h 2 allergenicity than fructose. This study will provide a theoretical basis for selecting appropriate reducing sugars and preparing hypoallergenic products containing peanuts.

Dajianzhong decoction ameliorated D-gal-induced cognitive aging by triggering mitophagy in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Dajianzhong decoction (DJZ) is a classical famous formula for treating yang-deficiency-syndrome in traditional Chinese medicine and recorded in Jin-Kui-Yao-Lue in Dynasty of Dong Han. Cognitive aging can present similar features of mitochondrial energy deficits to the clinical features of Yang deficiency. However, there is poor understanding of the effects of DJZ treatment on mitophagy in cognitive aging.

AIM OF THE STUDY

The aims of this work were to decipher the effectiveness and mechanism of DJZ against cognitive aging, focusing on mitophagy.

MATERIALS AND METHODS

YFP-Parkin HeLa cells, D-galactose (D-gal) -induced mice (500 mg/kg for 35 d, s. c.) and SH-SY5Y cells (80 mg/ml for 6 h) were established. Firstly, the formation of YFP-Parkin puncta (a well-known mitophagy marker) in YFP-Parkin HeLa cells was employed to discover the mitophagy induction of DJZ. Moreover, the genes and proteins related to PINK1/Parkin pathway and mitochondrial functions were evaluated after treatment with DJZ in vivo (3.5 g/kg or 1.75 g/kg, i. g, 35 d) and in vitro (0.2, 2 and 20 μg/ml, 12 h). Furthermore, the effectiveness of DJZ (3.5 g/kg or 1.75 g/kg, i. g) for alleviating cognitive aging and nerve damage was measured in D-gal mice. Finally, siPINK1 was applied to reverse validation of DJZ in vitro.

RESULTS

The formation of YFP-Parkin puncta in YFP-Parkin HeLa cells was markedly induced by DJZ in a dose-dependent manner. The immunofluorescence intensity of Parkin and the protein expression of Parkin in mitochondrial membrane in D-gal mice were significantly increased after treatment of DJZ. The inhibition of PINK1/Parkin pathway in D-gal-induced mice and SH-SY5Y cells was significantly activated by DJZ. Simultaneously, the impairment of mitochondrial functions induced by D-gal were markedly reversed by DJZ. In addition, DJZ significantly ameliorated the neuropathological injury and cognitive declines in D-gal mice. Finally, after PINK1 was knocked down by siPINK1 in vitro, the neuroprotective effects of DJZ and the Parkin enhancement effect of DJZ were markedly reversed.

CONCLUSION

Our findings firstly showed DJZ could relieve cognitive aging through facilitating PINK1/Parkin-mediated mitophagy to protect against mitochondrial functions, indicating DJZ may be regarded as a promising intervention in cognitive aging.

Kinsenoside from Anoectochilus roxburghii (Wall.) Lindl. suppressed oxidative stress to attenuate aging-related learning and memory impairment via ERK/Nrf2 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Anoectochilusroxburghii (Wall.) Lindl. (AR), as an exceptionally valuable traditional Chinese medicine, has been widely used to treat hepatitis, cancer, diabetes, etc. But, the effects and the primary functioning element of AR on attenuating aging and aging-related learning and memory degradation has not yet been explored.

AIM OF THE STUDY

This study aimed at exploring the protective property of aqueous extract of AR (AEAR) on alleviation of aging and aging-related learning and memory impairment in vivo, and further investigating the main active ingredient and mechanism of AEAR.

MATERIALS AND METHODS

D-galactose (D-gal) induced aging mice and HT22 cells exposed with L-Glutamic acid (Glu) were used as in vivo and in vitro model, separately. The effects of AEAR on aging and aging-related learning and memory degradation were explored by using morris water maze test, immunohistochemistry staining, biochemistry assay, etc. The effects and mechanism of AEAR and Kinsenoside (Kin) on antioxidation in vitro were investigated by cell viability assay, biochemistry assay, qRT-PCR, western blotting and molecular docking studies.

RESULTS

Treatment with AEAR (containing 69.52 ± 0.85% Kin, i.g.) for 63 days, alleviated low growth rate, abnormal brain, liver and thymus index, and decline in learning and memory capability of aging mice. Meanwhile, AEAR inhibited the decreased activities of SOD and GSH-PX, the decline in the ratio of GSH to GSSG, and the increase of MDA in both serum and brain, and also promoted the Nrf2 nuclear translocation in brain of aging mice induced by D-gal. The effects of AEAR on alleviating abnormal physiological characteristics, attenuating learning and memory impairment, and inhibiting oxidative stress in aging mice was similar to or even better than that of Vc. In HT22 cells exposed with Glu, Kin increased the cell viability, up-regulated the activities of SOD and GSH-PX, enhanced the ratio of GSH to GSSG, and down-regulated MDA, which was superior to AEAR. Kin up-regulated the ratio of p-ERK1/2 to ERK1/2, promoted the Nrf2 nuclear translocation and its downstream target genes, i.e. HO-1, NQO-1, GCLC and GCLM expression at the mRNA and protein levels, which were consistent with AEAR. Further, molecular docking results also confirmed that Kin had strong binding energy with ERK1 and ERK2.

CONCLUSION

The present study indicated that Kin could alleviate the oxidative stress in aging mice via activating the ERK/Nrf2 signaling pathway, in order to attenuate aging and aging-related learning and memory impairment, as the main active ingredient of AR.

The α-Gal epitope - the cause of a global allergic disease

The galactose-α-1,3-galactose (α-Gal) epitope is the cause of a global allergic disease, the α-Gal syndrome (AGS). It is a severe form of allergy to food and products of mammalian origin where IgE against the mammalian carbohydrate, α-Gal, is the cause of the allergic reactions. Allergic reactions triggered by parenterally administered α-Gal sources appear immediately, but those triggered via the oral route appear with a latency of several hours. The α-Gal epitope is highly immunogenic to humans, apes and old-world monkeys, all of which produce anti-α-Gal antibodies of the IgM, IgA and IgG subclasses. Strong evidence suggests that in susceptible individuals, class switch to IgE occurs after several tick bites. In this review, we discuss the strong immunogenic role of the α-Gal epitope and its structural resemblance to the blood type B antigen. We emphasize the broad abundance of α-Gal in different foods and pharmaceuticals and the allergenicity of various α-Gal containing molecules. We give an overview of the association of tick bites with the development of AGS and describe innate and adaptive immune response to tick saliva that possibly leads to sensitization to α-Gal. We further discuss a currently favored hypothesis explaining the mechanisms of the delayed effector phase of the allergic reaction to α-Gal. We highlight AGS from a clinical point of view. We review the different clinical manifestations of the disease and the prevalence of sensitization to α-Gal and AGS. The usefulness of various diagnostic tests is discussed. Finally, we provide different aspects of the management of AGS. With climate change and global warming, the tick density is increasing, and their geographic range is expanding. Thus, more people will be affected by AGS which requires more knowledge of the disease.

Design, synthesis and biological evaluation of the positional isomers of the galactose conjugates able to target hepatocellular carcinoma cells via ASGPR-mediated cellular uptake and cytotoxicity

Galactose as a recognizing motif for asialoglycoprotein receptor (ASGPR) is a widely accepted vector to deliver cytotoxic agents in the therapy of hepatocellular carcinoma (HCC), however, the individual hydroxyl group of galactose (Gal) contributed to recognizing ASGPR is obscure and remains largely unanswered in the design of glycoconjugates. Herein, we designed and synthesized five positional isomers of Gal-anthocyanin Cy5.0 conjugates and three Gal-doxorubicin (Dox) isomers, respectively. The fluorescence intensity of Gal-Cy5.0 conjugates accumulated in cancer cells hinted the optimal modification sites of positions C2 and C6. Comparing to the cytotoxicity of other conjugates, C2-Gal-Dox (11) was the most potent. Moreover, Gal-Dox conjugates significantly the toxicity of Dox. A progressively lower internalization capacity and siRNA technology implied the cellular uptake and cytotoxicity directly related to the ASGPR expression level. Accordingly, position C2 of galactose may be the best substitution site via ASGPR mediation in the design of anti-HCC glycoconjugates.