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Cephalostachyum pingbianense (Hsueh & Y.M. Yang ex Yi et al.) D.Z. Li & H.Q. Yang is unique among bamboo species for its ability to produce bamboo shoots in all seasons under natural conditions. Apart from the physiological mechanism, information regarding the effects of endophytic microorganisms on this full-year shooting characteristic is limited. We hypothesize that root endophytic microorganisms will have a positive impact on the full-year bamboo shooting characteristic of C. pingbianense by increasing the availability or supply of nutrients. To identify the seasonal variations in the root endophytic bacterial and fungal communities of C. pingbianense, and to assess their correlation with bamboo shoot productivity, the roots of C. pingbianense were selected as research materials, and the 16S rRNA and ITS rDNA genes of root endophytic microorganisms were sequenced using the Illumina platform. Following this sequencing, raw sequencing reads were processed, and OTUs were annotated. Alpha and beta diversity, microbial composition, and functional predictions were analyzed, with correlations to bamboo shoot numbers assessed. The results showed that seasonal changes significantly affected the community diversity and structure of root endophytic microbes of C. pingbianense. Bacterial communities in root samples from all seasons contained more nitrogen-fixing microorganisms, with members of the Burkholderiales and Rhizobiales predominating. The relative abundances of ectomycorrhizal and arbuscular mycorrhizal fungi in the autumn sample were significantly higher than in other seasons. Correlation analysis revealed that the bamboo shoot productivity was significantly and positively correlated with bacterial functions of nitrogen fixation, arsenate detoxification, and ureolysis, as well as with symbiotrophic fungi, ectomycorrhizal fungi, and arbuscular mycorrhizal fungi. At the genus level, the bacterial genus Herbaspirillum and the fungal genera Russula, unclassified_f_Acaulosporaceae, and unclassified_f_Glomeraceae were found to have a significant positive correlation with bamboo shoot number. Our study provides an ecological perspective for understanding the highly productive attribute of C. pingbianense and offers new insights into the forest management of woody bamboos.
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The triggering receptor expressed on myeloid cells-2 (TREM2), a pivotal innate immune receptor, orchestrates functions such as inflammatory responses, phagocytosis, cell survival, and neuroprotection. TREM2 variants R47H and R62H have been associated with Alzheimer's disease, yet the underlying mechanisms remain elusive. Our previous research established that TREM2 binds to heparan sulfate (HS) and variants R47H and R62H exhibit reduced affinity for HS. Building upon this groundwork, our current study delves into the interplay between TREM2 and HS and its impact on microglial function. We confirm TREM2's binding to cell surface HS and demonstrate that TREM2 interacts with HS, forming HS-TREM2 binary complexes on microglia cell surfaces. Employing various biochemical techniques, including surface plasmon resonance, low molecular weight HS microarray screening, and serial HS mutant cell surface binding assays, we demonstrate TREM2's robust affinity for HS, and the effective binding requires a minimum HS size of approximately 10 saccharide units. Notably, TREM2 selectively binds specific HS structures, with 6-O-sulfation and, to a lesser extent, the iduronic acid residue playing crucial roles. N-sulfation and 2-O-sulfation are dispensable for this interaction. Furthermore, we reveal that 6-O-sulfation is essential for HS-TREM2 ternary complex formation on the microglial cell surface, and HS and its 6-O-sulfation are necessary for TREM2-mediated ApoE3 uptake in microglia. By delineating the interaction between HS and TREM2 on the microglial cell surface and demonstrating its role in facilitating TREM2-mediated ApoE uptake by microglia, our findings provide valuable insights that can inform targeted interventions for modulating microglial functions in Alzheimer's disease.
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Heparitina Sulfato , Glicoproteínas de Membrana , Microglía , Receptores Inmunológicos , Microglía/metabolismo , Heparitina Sulfato/metabolismo , Heparitina Sulfato/química , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/química , Receptores Inmunológicos/metabolismo , Receptores Inmunológicos/genética , Receptores Inmunológicos/química , Animales , Humanos , Ratones , Unión Proteica , Membrana Celular/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/genéticaRESUMEN
Alzheimer's disease is a fatal chronic neurodegenerative condition marked by a gradual decline in cognitive abilities and impaired vascular function within the central nervous system. This affliction initiates its insidious progression with the accumulation of two aberrant protein entities including Aß plaques and neurofibrillary tangles. These chronic elements target distinct brain regions, steadily erasing the functionality of the hippocampus and triggering the erosion of memory and neuronal integrity. Several assumptions are anticipated for AD as genetic alterations, the occurrence of Aß plaques, altered processing of amyloid precursor protein, mitochondrial damage, and discrepancy of neurotropic factors. In addition to Aß oligomers, the deposition of tau hyper-phosphorylates also plays an indispensable part in AD etiology. The brain comprises a complex network of capillaries that is crucial for maintaining proper function. Tau is expressed in cerebral blood vessels, where it helps to regulate blood flow and sustain the blood-brain barrier's integrity. In AD, tau pathology can disrupt cerebral blood supply and deteriorate the BBB, leading to neuronal neurodegeneration. Neuroinflammation, deficits in the microvasculature and endothelial functions, and Aß deposition are characteristically detected in the initial phases of AD. These variations trigger neuronal malfunction and cognitive impairment. Intracellular tau accumulation in microglia and astrocytes triggers deleterious effects on the integrity of endothelium and cerebral blood supply resulting in further advancement of the ailment and cerebral instability. In this review, we will discuss the impact of tau on neurovascular impairment, mitochondrial dysfunction, oxidative stress, and the role of hyperphosphorylated tau in neuron excitotoxicity and inflammation.
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Enfermedad de Alzheimer , Proteínas tau , Humanos , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Proteínas tau/metabolismo , Animales , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Encéfalo/metabolismo , Encéfalo/patologíaRESUMEN
Alzheimer's disease (AD) is a debilitating neurodegenerative disease characterized by the accumulation of extracellular amyloid-ß peptides (Aß) within the cerebral parenchyma and vasculature, which is known as cerebral amyloid angiopathy (CAA). This study utilized confocal imaging to investigate heparan sulfate (HS) expression within the cerebrovasculature and its associations with Aß, gender, and ApoE4 genotype in AD. Our investigation revealed elevated levels of HS in the cerebrovasculature of AD patients with severe CAA. Additionally, these patients exhibited higher HS colocalization with Aß in the cerebrovasculature, including both endothelial and vascular smooth muscle cell compartments. Intriguingly, a reversal in the polarized expression of HS within the cerebrovasculature was detected in AD patients with severe CAA. Furthermore, male patients exhibited lower levels of both parenchymal and cerebrovascular HS. Additionally, ApoE4 carriers displayed heightened cerebrovascular Aß expression and a tendency of elevated cerebrovascular HS levels in AD patients with severe CAA. Overall, these findings reveal potential intricate interplay between HS, Aß, ApoE, and vascular pathology in AD, thereby underscoring the potential roles of cerebrovascular HS in CAA development and AD pathology. Further study of the underlying mechanisms may present novel therapeutic avenues for AD treatment.
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Enfermedad de Alzheimer , Angiopatía Amiloide Cerebral , Enfermedades Neurodegenerativas , Humanos , Masculino , Enfermedad de Alzheimer/genética , Apolipoproteína E4/genética , Péptidos beta-Amiloides , Heparitina SulfatoRESUMEN
Background: Plant health is directly related to the change in native microbial diversity and changes in soil health have been implicated as one of the main cause of root rot. However, scarce information is present regarding allelopathic relationship of Panax notoginseng root exudates and pathogenic fungi Fusarium oxysporum in a continuous cropping system. Methods: We analyzed P. notoginseng root exudate in the planting soil for three successive years to determine phenolic acid concentration using GC-MS and HPLC followed by effect on the microbial community assembly. Antioxidant enzymes were checked in the roots to confirm possible resistance in P. notoginseng. Results: Total 29 allelochemicals in the planting soil extract was found with highest concentration (10.54 %) of p-hydroxybenzoic acid. The HPLC showing a year-by-year decrease in p-hydroxybenzoic acid content in soil of different planting years, and an increase in population of F. oxysporum. Moreover, community analysis displayed negative correlation with 2.22 mmol. L-1 of p-hydroxybenzoic acid correspond to an 18.1 % population of F. oxysporum. Furthermore, in vitro plate assay indicates that medium dose of p-hydroxybenzoic acid (2.5-5 mmol. L-1) can stimulate the growth of F. oxysporum colonies and the production of macroconidia, as well as cell wall-degrading enzymes. We found that 2-3 mmol. L-1 of p-hydroxybenzoic acid significantly increased the population of F. oxysporum. Conclusion: In conclusion, our study suggested that p-hydroxybenzoic acid have negative effect on the root system and modified the rhizosphere microbiome so that the host plant became more susceptible to root rot disease.
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To explore the regulation mechanism of endogenous phytohormones on rhizome bud germination in Cephalostachyum pingbianense, the contents of IAA, ABA, GA, and CTK in seven above- and under-ground bamboo structure components were determined using enzyme-linked immunosorbent assays (ELISA). The results showed that a higher content of IAA, GA, and CTK all year was found in above-ground components and dormant rhizome buds. Meanwhile, a higher ABA content in young shoots and a lower ABA content in the culm base and dormant rhizome buds were detected during the peak period of shooting. The amounts of emerging shoots and the grown bamboo culms were positively correlated with the content of IAA and the ratio of IAA/ABA and (IAA + CTK + GA)/ABA, while they were negatively correlated with the ratio of CTK/IAA in dormant rhizome buds. The all-year high contents of IAA (19-31 ng/g) and ABA (114-144 ng/g) in rhizome buds, as well as interactions among four hormones, may be the key physiological mechanisms to maintain rhizome bud germination throughout the year in C. pingbianense. As C. pingbianense is a special bamboo species of multi-season shoot sprouting, the above results may supplement scientific data for a comprehensive understanding of physiological mechanisms within the bamboo subfamily.
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TRP (Transient receptor potential) channels are integral membrane proteins consisting of a superfamily of cation channels that allow permeability of both monovalent and divalent cations. TRP channels are subdivided into six subfamilies: TRPC, TRPV, TRPM, TRPP, TRPML, and TRPA, and are expressed in almost every cell and tissue. TRPs play an instrumental role in the regulation of various physiological processes. TRP channels are extensively represented in brain tissues and are present in both prokaryotes and eukaryotes, exhibiting responses to several mechanisms, including physical, chemical, and thermal stimuli. TRP channels are involved in the perturbation of Ca2+ homeostasis in intracellular calcium stores, both in neuronal and non-neuronal cells, and its discrepancy leads to several neuronal disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and Amyotrophic lateral sclerosis (ALS). TRPs participate in neurite outgrowth, receptor signaling, and excitotoxic cell death in the central nervous system. Understanding the mechanism of TRP channels in neurodegenerative diseases may extend to developing novel therapies. Thus, this review articulates TRP channels' physiological and pathological role in exploring new therapeutic interventions in neurodegenerative diseases.
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HS3ST1 is a genetic risk gene associated with Alzheimer's disease (AD) and overexpressed in patients, but how it contributes to the disease progression is unknown. We report the analysis of brain heparan sulfate (HS) from AD and other tauopathies using a LC-MS/MS method. A specific 3-O-sulfated HS displayed sevenfold increase in the AD group (n = 14, P < 0.0005). Analysis of the HS modified by recombinant sulfotransferases and HS from genetic knockout mice revealed that the specific 3-O-sulfated HS is made by 3-O-sulfotransferase isoform 1 (3-OST-1), which is encoded by the HS3ST1 gene. A synthetic tetradecasaccharide (14-mer) carrying the specific 3-O-sulfated domain displayed stronger inhibition for tau internalization than a 14-mer without the domain, suggesting that the 3-O-sulfated HS is used in tau cellular uptake. Our findings suggest that the overexpression of HS3ST1 gene may enhance the spread of tau pathology, uncovering a previously unidentified therapeutic target for AD.
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Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/genética , Cromatografía Liquida , Sulfatos , Espectrometría de Masas en Tándem , Heparitina Sulfato , Sulfotransferasas/genética , Sulfotransferasas/metabolismo , Ratones Noqueados , Encéfalo/metabolismoRESUMEN
Apolipoproteinâ E (ApoE)'s ϵ4 alle is the most important genetic risk factor for late onset Alzheimer's Disease (AD). Cell-surface heparan sulfate (HS) is a cofactor for ApoE/LRP1 interaction and the prion-like spread of tau pathology between cells. 3-O-sulfo (3-O-S) modification of HS has been linked to AD through its interaction with tau, and enhanced levels of 3-O-sulfated HS and 3-O-sulfotransferases in the AD brain. In this study, we characterized ApoE/HS interactions in wildtype ApoE3, AD-linked ApoE4, and AD-protective ApoE2 and ApoE3-Christchurch. Glycan microarray and SPR assays revealed that all ApoE isoforms recognized 3-O-S. NMR titration localized ApoE/3-O-S binding to the vicinity of the canonical HS binding motif. In cells, the knockout of HS3ST1-a major 3-O sulfotransferase-reduced cell surface binding and uptake of ApoE. 3-O-S is thus recognized by both tau and ApoE, suggesting that the interplay between 3-O-sulfated HS, tau and ApoE isoforms may modulate AD risk.
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Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/metabolismo , Apolipoproteína E3/genética , Apolipoproteínas E/química , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Heparitina Sulfato/química , Isoformas de Proteínas/metabolismoRESUMEN
Alzheimer's disease (AD) is the most common form of dementia. Currently, there is no effective treatment for AD, as its etiology remains poorly understood. Mounting evidence suggests that the accumulation and aggregation of amyloid-ß peptides (Aß), which constitute amyloid plaques in the brain, is critical for initiating and accelerating AD pathogenesis. Considerable efforts have been dedicated to shedding light on the molecular basis and fundamental origins of the impaired Aß metabolism in AD. Heparan sulfate (HS), a linear polysaccharide of the glycosaminoglycan family, co-deposits with Aß in plaques in the AD brain, directly binds and accelerates Aß aggregation, and mediates Aß internalization and cytotoxicity. Mouse model studies demonstrate that HS regulates Aß clearance and neuroinflammation in vivo. Previous reviews have extensively explored these discoveries. Here, this review focuses on the recent advancements in understanding abnormal HS expression in the AD brain, the structural aspects of HS-Aß interaction, and the molecules involved in modulating Aß metabolism through HS interaction. Furthermore, this review presents a perspective on the potential effects of abnormal HS expression on Aß metabolism and AD pathogenesis. In addition, the review highlights the importance of conducting further research to differentiate the spatiotemporal components of HS structure and function in the brain and AD pathogenesis.
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Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/metabolismo , Proteoglicanos de Heparán Sulfato/metabolismo , Péptidos beta-Amiloides/genética , Péptidos beta-Amiloides/metabolismo , Heparitina Sulfato/metabolismo , Encéfalo/metabolismoRESUMEN
Tau spreading in Alzheimer's disease is mediated by cell surface heparan sulfate (HS). As a class of sulfated polysaccharides, fucoidans might compete with HS to bind tau, resulting in the cessation of tau spreading. The structural determinants of fucoidans for competition with HS binding to tau are not well understood. Sixty previously prepared fucoidans/glycans with different structural determinants were used to determine their binding abilities to tau using SPR and AlphaLISA. Finally, it was found that fucoidans had two fractions (sulfated galactofucan (SJ-I) and sulfated heteropolysaccharide (SJ-GX-3)), which exhibited strong binding abilities than heparin. Tau cellular uptake assays using wild type mouse lung endothelial cell lines were performed. It was shown SJ-I and SJ-GX-3 inhibited tau-cell interaction and tau cellular uptake, suggesting that fucoidans might be good candidates for inhibiting tau spreading. NMR titration mapped fucoidans binding sites, which could provide the theoretical basis for the design of tau spreading inhibitors.
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Enfermedad de Alzheimer , Células Endoteliales , Animales , Ratones , Membrana Celular , Transporte Biológico , Heparitina Sulfato , SulfatosRESUMEN
The heparan sulfate proteoglycans (HSPGs) are glycoproteins that consist of a proteoglycan "core" protein and covalently attached heparan sulfate (HS) chain. HSPGs are ubiquitously expressed in mammalian cells on the cell surface and in the extracellular matrix (ECM) and secretory vesicles. Within HSPGs, the protein cores determine when and where HSPG expression takes place, and the HS chains mediate most of HSPG's biological roles through binding various protein ligands, including cytokines, chemokines, growth factors and receptors, morphogens, proteases, protease inhibitors, and ECM proteins. Through these interactions, HSPGs modulate cell proliferation, adhesion, migration, invasion, and angiogenesis to display essential functions in physiology and pathology. Under physiological conditions, the expression and localization of HSPGs are finely regulated to orchestrate their physiological functions, and this is disrupted in cancer. The HSPG dysregulation elicits multiple oncogenic signaling, including growth factor signaling, ECM and Integrin signaling, chemokine and immune signaling, cancer stem cell, cell differentiation, apoptosis, and senescence, to prompt cell transformation, proliferation, tumor invasion and metastasis, tumor angiogenesis and inflammation, and immunotolerance. These oncogenic roles make HSPGs an attractive pharmacological target for anti-cancer therapy. Several therapeutic strategies have been under development, including anti-HSPG antibodies, peptides and HS mimetics, synthetic xylosides, and heparinase inhibitors, and shown promising anti-cancer efficacy. Therefore, much progress has been made in this line of study. However, it needs to bear in mind that the roles of HSPGs in cancer can be either oncogenic or tumor-suppressive, depending on the HSPG and the cancer cell type with the underlying mechanisms that remain obscure. Further studies need to address these to fill the knowledge gap and rationalize more efficient therapeutic targeting.
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Proteoglicanos de Heparán Sulfato , Neoplasias , Animales , Humanos , Proteoglicanos de Heparán Sulfato/metabolismo , Proteoglicanos de Heparán Sulfato/uso terapéutico , Neoplasias/patología , Heparitina Sulfato/metabolismo , Heparitina Sulfato/uso terapéutico , Neovascularización Patológica/tratamiento farmacológico , Diferenciación Celular , Mamíferos/metabolismoRESUMEN
Tauopathies are a class of neurodegenerative diseases, including Alzheimer's disease, and are characterized by intraneuronal tau inclusion in the brain and the patient's cognitive decline with obscure pathogenesis. Heparan sulfate proteoglycans, a major type of extracellular matrix, have been believed to involve in tauopathies. The heparan sulfate proteoglycans co-deposit with tau in Alzheimer's patient brain, directly bind to tau and modulate tau secretion, internalization, and aggregation. This review summarizes the current understanding of the functions and the modulated molecular pathways of heparan sulfate proteoglycans in tauopathies, as well as the implication of dysregulated heparan sulfate proteoglycan expression in tau pathology and the potential of targeting heparan sulfate proteoglycan-tau interaction as a novel therapeutic option.
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Proteoglicanos de Heparán Sulfato , Tauopatías , Humanos , Enfermedad de Alzheimer/metabolismo , Matriz Extracelular/metabolismo , Tauopatías/metabolismoRESUMEN
Heparin has been documented to reduce myocardial injury caused by ischemia/reperfusion (I/R), but its clinical application is limited due to its strong intrinsic anticoagulant property. Some desulfated derivatives of heparin display low anticoagulant activity and may have potential value as therapeutic agents for myocardial I/R injury. In this study, we observed that 6-O-desulfated heparin, a desulfated derivative of heparin, shortened the activated partial thromboplastin time and exhibited lower anticoagulant activity compared with heparin or 2-O-desulfated heparin (another desulfated derivative of heparin). Then, we explored whether 6-O-desulfated heparin could protect against myocardial I/R injury, and elucidated its possible mechanisms. Administration of 6-O-desulfated heparin significantly reduced creatine kinase activity, myocardial infarct size and cell apoptosis in mice subjected to 30 min of myocardial ischemia following 2 h of reperfusion, accompanied by a reverse in miR-199a-5p elevation, klotho downregulation and reactive oxygen species (ROS) accumulation. In cultured H9c2 cells, the mechanism of 6-O-desulfated heparin against myocardial I/R injury was further explored. Consistent with the results in vivo, 6-O-desulfated heparin significantly ameliorated hypoxia/reoxygenation-induced injury, upregulated klotho and decreased miR-199a-5p levels and ROS accumulation, and these effects were reversed by miR-199a-5p mimics. In conclusion, these results suggested that 6-O-desulfated heparin with lower anticoagulant activity attenuated myocardial I/R injury through miR-199a-5p/klotho and ROS signaling. Our study may also indicate that 6-O-desulfated heparin, as an excellent heparin derivative, is a potential therapeutic agent for myocardial I/R injury.
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Heparina , Proteínas Klotho , MicroARNs , Daño por Reperfusión Miocárdica , Animales , Ratones , Apoptosis , Modelos Animales de Enfermedad , Heparina/farmacología , Heparina/uso terapéutico , Proteínas Klotho/metabolismo , MicroARNs/genética , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/metabolismo , Transducción de SeñalRESUMEN
BACKGROUND AND OBJECTIVES: This study investigated the effect of continuous perioperative nutritional support provided by a multidisciplinary team (MDT) to patients who underwent surgery for head and neck cancer (HNC). METHODS AND STUDY DESIGN: This study enrolled 99 patients with HNC and divided them into two groups: a management group (n=48), comprising patients who underwent surgery between August and December 2020 and received continuous perioperative nutritional support from the MDT; and a control group (n=51), comprising patients who underwent surgery between June and December 2017 and received routine nutritional guidance. Data on weight, nutritional indicators, and the prognostic nutritional index (PNI) were collected. We compared the changes in weight, nutritional indicators, PNI, Patient-Generated Subjective Global Assessment (PG-SGA) scores, and body composition. Factors influencing the PNI were analysed. RESULTS: The minimum weight, nutritional indicator, and PNI values observed postoperatively and at discharge were lower than those observed at admission. The serum nutritional index values observed at discharge and minimum PNI values observed postoperatively and at discharge were higher in the management group than in the control group. The PG-SGA score at 2 weeks postoperatively was higher than that on the day of surgery in the management group. The discharge PNI was influenced by management and age in these HNC surgical patients. In the management group, body composition data did not differ significantly between the preoperative and 1-, 2-, and 3-week postoperative time points. CONCLUSIONS: Continuous perioperative nutritional support by an MDT can improve the weight and serum nutritional index of patients receiving surgery for HNC and improve the PNI at discharge.
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Neoplasias de Cabeza y Cuello , Evaluación Nutricional , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Estado Nutricional , Apoyo Nutricional , PronósticoRESUMEN
Coronavirus disease 2019 (COVID-19) has caused massive health and economic disasters worldwide. Although several vaccines have effectively slowed the spread of the virus, their long-term protection and effectiveness against viral variants are still uncertain. To address these potential shortcomings, this study proposes a peptide-based vaccine to prevent COVID-19. A total of 15 B cell epitopes of the wild-type severe acute respiratory coronavirus 2 (SARS-CoV-2) spike (S) protein were selected, and their HLA affinities predicted in silico. Peptides were divided into two groups and tested in C57BL/6 mice with either QS21 or Al(OH)3 as the adjuvant. Our results demonstrated that the peptide-based vaccine stimulated high and durable antibody responses in mice, with the T and B cell responses differing based on the type of adjuvant employed. Using epitope mapping, we showed that our peptide-based vaccine produced antibody patterns similar to those in COVID-19 convalescent individuals. Moreover, plasma from vaccinated mice and recovered COVID-19 humans had the same neutralizing activity when tested with a pseudo particle assay. Our data indicate that this adjuvant peptide-based vaccine can generate sustainable and effective B and T cell responses. Thus, we believe that our peptide-based vaccine can be a safe and effective vaccine against COVID-19, particularly because of the flexibility of including new peptides to prevent emerging SARS-CoV-2 variants and avoiding unwanted autoimmune responses.
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COVID-19 , Vacunas Virales , Animales , COVID-19/prevención & control , Vacunas contra la COVID-19 , Humanos , Ratones , Ratones Endogámicos C57BL , Péptidos , SARS-CoV-2RESUMEN
Roundabout 4 (Robo4) is a transmembrane receptor that expresses specifically in endothelial cells. Soluble Robo4 was reported in the human plasma and mouse serum and is inhibitory towards FGF- and VEGF-induced angiogenesis. It remains unknown how soluble Robo4 is generated and if soluble Robo4 regulates additional angiogenic signaling. Here, we report soluble Robo4 is the product of constitutive ectodomain shedding of endothelial cell surface Robo4 by disintegrin metalloproteinases ADAM10 and ADAM17 and acts to inhibit angiogenic Slit3 signaling. Meanwhile, the ligand Slit3 induces cell surface receptor Robo4 endocytosis to shield Robo4 from shedding, showing Slit3 inhibits Robo4 shedding to enhance Robo4 signaling. Our study delineated ADAM10 and ADAM17 are Robo4 sheddases, and ectodomain shedding, including negative regulation by its ligand Slit3, represents a novel control mechanism of Robo4 signaling in angiogenesis.
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Células Endoteliales , Proteínas de la Membrana , Proteína ADAM10/metabolismo , Proteína ADAM17/metabolismo , Animales , Células Endoteliales/metabolismo , Ligandos , Proteínas de la Membrana/metabolismo , Ratones , Neovascularización Patológica/metabolismo , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismoRESUMEN
Heparan sulfate (HS) is a linear polysaccharide with complex structures and modulates a wide range of biological functions. Elucidating the structure-function relationship of HS has been challenging. Recently, we generated a HS mutant mouse lung endothelial cell library by systematic deletion of HS genes expressed in the cell individually or in their combination. Here, we describe the experimental procedure using the mutant cell library to determine the structure-function relationship of HS in the regulation of FGF2-FGFR1 signaling at the levels of cell surface FGF2 binding and the downstream intracellular signaling activation. Our results demonstrated that strictly defined fine structure is required for HS to act as a co-receptor for FGF2-FGFR1 signaling.
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Transducción de Señal , Animales , Membrana Celular/metabolismo , Factor 2 de Crecimiento de Fibroblastos/genética , Heparitina Sulfato , Ratones , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genética , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/metabolismo , Relación Estructura-ActividadRESUMEN
Furin is one of the nine-member proprotein convertase family. Furin cleaves proteins with polybasic residues, which includes many viral glycoproteins such as SARS-Cov-2 spike protein. The cleavage is required for the activation of the proteins. Currently, the mechanisms that regulate Furin activity remain largely unknown. Here we demonstrated that Furin is a novel heparin/heparan sulfate binding protein by the use of biochemical and genetic assays. The KD is 9.78 nM based on the biolayer interferometry assay. Moreover, we found that sulfation degree, site-specific sulfation (N-sulfation and 3-O-sulfation), and iduronic acid are the major structural determinants for the binding. Furthermore, we found that heparin inhibits the enzymatic activity of Furin when pre-mixes heparin with either Furin or Furin substrate. We also found that the Furin binds with cells of different origin and the binding with the cells of lung origin is the strongest one. These data could advance our understanding of the working mechanism of Furin and will benefit the Furin based drug discovery such as inhibitors targeting the interaction between heparan sulfate and Furin for inhibition of viral infection.
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Furina , Heparitina Sulfato , Furina/metabolismo , Heparitina Sulfato/metabolismo , Humanos , SARS-CoV-2 , Glicoproteína de la Espiga del CoronavirusRESUMEN
Sapindus (Sapindus L.) is a widely distributed economically important tree genus that provides biodiesel, biomedical and biochemical products. However, with climate change, deforestation, and economic development, the diversity of Sapindus germplasms may face the risk of destruction. Therefore, utilising historical environmental data and future climate projections from the BCC-CSM2-MR global climate database, we simulated the current and future global distributions of suitable habitats for Sapindus using a Maximum Entropy (MaxEnt) model. The estimated ecological thresholds for critical environmental factors were: a minimum temperature of 0-20 °C in the coldest month, soil moisture levels of 40-140 mm, a mean temperature of 2-25 °C in the driest quarter, a mean temperature of 19-28 °C in the wettest quarter, and a soil pH of 5.6-7.6. The total suitable habitat area was 6059.97 × 104 km2, which was unevenly distributed across six continents. As greenhouse gas emissions increased over time, the area of suitable habitats contracted in lower latitudes and expanded in higher latitudes. Consequently, surveys and conservation should be prioritised in southern hemisphere areas which are in danger of becoming unsuitable. In contrast, other areas in northern and central America, China, and India can be used for conservation and large-scale cultivation in the future.