Computational Drug Discovery Methods (82)Protein Structure and Dynamics (64)Receptor Mechanisms and Signaling (60)Monoclonal and Polyclonal Antibodies Research (51)Ubiquitin and proteasome pathways (50)
Salivary gland proteins but not glycoconjugates have been previously studied in mosquito vectors of human diseases. Glycoconjugates from salivary gland-derived proteins from human-feeding tick vectors can elicit hypersensitivity reactions which may also occur with mosquito bites. Protein glycoconjugate in salivary glands of the principal arboviral vector Aedes aegypti and the rapidly spreading malaria vector Anopheles stephensi were investigated. Forty different lectins in a microarray were used to analyse glycoconjugates in salivary gland proteins from both mosquito species. Salivary gland glycoproteins of both mosquitoes possessed similar lectin-binding specificities. Lectin-binding profiles in both mosquitoes showed the significant presence of oligomannose N-linked glycans, O-linked glycans, a limited presence of glycan structures capped with terminal GalNAc, GlcNAc, β-linked Gal, αl-6 linked fucose, and no detectable sialic acids or terminal α-linked Gal in salivary gland glycoproteins. Aedes aegypti and An. stephensi possess similar salivary gland protein glycoconjugates to mosquito larval tissues. They differ from arachnid ticks in lacking detectable α-gal epitopes that are responsible for red meat allergy caused by tick bites.
International journal of biological macromolecules •
This study aimed to investigate the structural characterization, conformational properties, and hepatoprotectiveactivity of acidic polysaccharide (DNLPS-3) from Dendrobium nobile flower. DNLPS-3 with molecular weights of 15.65 KDa was composed of Fuc: Rha: Ara: Gal: Glc: Xyl: GalA: GlcA in a molar ratio of 0.26%: 2.38%: 4.47%: 3.55%: 0.43%: 17.84%: 69.80%: 1.26%. Structural analysis with methylation indicated that DNLPS-3 mainly contained T-Ara(f), T-Xyl(p), T-Gal(p)A, 3-Gal(p)A, 4-Gal(p)A, 3,4-Gal(p)A, 3,4-Glc(p), 2,4-Gal(p)A, 2,3,4-Gal(p), 4,6-Gal(p), 3,4,6-Gal(p). NMR results show that DNLPS-3 may be a pectin polysaccharide with →4)-α-Gal(p)A-(→main chain. In vitro experiments showed that DNLPS-3 exhibited significant hepatoprotective effects. The effect was achieved by reducing the activities of ALT and AST, suppressing the production of LDH and MDA, and enhancing the anti-oxidant activities of SOD and GSH, and the specific mechanism of its hepatoprotective effect is that DNLPS-3 up-regulates Nrf2/HO-1 pathway protein expression.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery •
To investigate the physicochemical properties, osteogenic properties, and osteogenic ability in rabbit model of femoral condylar defect of acellular dermal matrix (ADM)/dicalcium phosphate (DCP) composite scaffold. ADM/DCP composite scaffolds were prepared by microfibril technique, and the acellular effect of ADM/DCP composite scaffolds was detected by DNA residue, fat content, and α-1，3-galactosyle (α-Gal) epitopes; the microstructure of scaffolds was characterized by field emission scanning electron microscopy and mercury porosimetry; X-ray diffraction was used to analyze the change of crystal form of scaffold; the solubility of scaffolds was used to detect the pH value and calcium ion content of the solution; the mineralization experiment was used to observe the surface mineralization. Twelve healthy male New Zealand white rabbits were selected to prepare the femoral condylar defect models, and the left and right defects were implanted with ADM/DCP composite scaffold (experimental group) and skeletal gold artificial bone repair material (control group), respectively. Gross observation was performed at 6 and 12 weeks after operation; Micro-CT was used to detect and quantitatively analyze the related indicators [bone volume (BV), bone volume/tissue volume (BV/TV), bone surface/bone volume (BS/BV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), bone mineral density (BMD)], and HE staining and Masson staining were performed to observe the repair of bone defects and the maturation of bone matrix. Gross observation showed that the ADM/DCP composite scaffold was a white spongy solid. Compared with ADM, ADM/DCP composite scaffolds showed a significant decrease in DNA residue, fat content, and α-Gal antigen content ( <0.05). Field emission scanning electron microscopy showed that the ADM/DCP composite scaffold had a porous structure, and DCP particles were attached to the porcine dermal fibers. The porosity of the ADM/DCP composite scaffold was 76.32%±1.63% measured by mercury porosimetry. X-ray diffraction analysis showed that the crystalline phase of DCP in the ADM/DCP composite scaffolds remained intact. Mineralization results showed that the hydroxyapatite layer of ADM/DCP composite scaffolds was basically mature. The repair experiment of rabbit femoral condyle defect showed that the incision healed completely after operation without callus or osteophyte. Micro-CT showed that bone healing was complete and a large amount of new bone tissue was generated in the defect site of the two groups, and there was no difference in density between the defect site and the surrounding bone tissue, and the osteogenic properties of the two groups were equivalent. There was no significant difference in BV, BV/TV, BS/BV, Tb.Th, Tb.N, and BMD between the two groups ( >0.05), except that the Tb.Sp in the experimental group was significantly higher than that in the control group ( <0.05). At 6 and 12 weeks after operation, HE staining and Masson staining showed that the new bone and autogenous bone fused well in both groups, and the bone tissue tended to be mature. The ADM/DCP composite scaffold has good biocompatibility and osteogenic ability similar to the artificial bone material in repairing rabbit femoral condylar defects. It is a new scaffold material with potential in the field of bone repair.
In studies to date, meshes based on extracellular matrix (ECM) have been extensively used in clinical applications. Unfortunately, little is known about the function of the immunogenic residual, absorbable profile during the tissue repair process. Moreover, there needs to be a recognized preclinical animal model to investigate the safety and efficacy of extracellular matrix meshes. Herein, we designed and fabricated a kind of SIS mesh followed by a scanned electron micrograph characterization and tested α-Gal antigen clearance rate and DNA residual. In order to prove the biocompatibility of the SIS mesh, cell viability, chemotaxis assay and local tissue reaction were assessed by MTT and RTCA cytotoxicity test in vitro as well as implantation and degradation experiments in vivo. Furthermore, we developed a stable preclinical animal model in the porcine ventral hernia repair investigation, which using laparoscopic plus open hybridization method to evaluate tissue adhesion, explant mechanical performance, and histologic analysis after mesh implantation. More importantly, we established a semi-quantitative scoring system to examine the ECM degradation, tissue remodeling and regeneration in the modified porcine surgical hernia model for the first time. Our results highlight the application prospect of the improved porcine ventral hernia model for the safety and efficacy investigation of hernia repair meshes.
Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences •
To evaluate the immunogenicity and osteogenic ability of animal-derived bone graft material decellularized with supercritical carbon dioxide. Porcine femurs were randomly divided into two groups after preliminary treatment, and decellularized with conventional method (control group) or supercritical carbon dioxide (experimental group). Allogenic demineralized bone matrix was used as positive control. Clearance rate of galactose-α-1, 3-galactose (α-Gal) antigen was determined by enzyme-linked immunosorbent assay and residual DNA was detected by a fluorescence method. Nine SPF-grade male athymic nude mice of 6 weeks old were randomly divided into experimental, control and positive control groups. Samples were implanted over biceps femoris muscle of athymic nude mice. The explants were collected 4 weeks post implantation. Hematoxylin and eosin (HE) staining and immunohistochemistry were applied to determine the osteogenic ability and bone tissue-associated protein expressions of the implants. The clearance rates of α-Gal antigen in the experimental group and the control group were (99.09±0.26)% and (30.18±2.02)%, respectively (=58.67, 0.01). The residual DNA of the experimental, control and positive control groups were (13.49±0.07), (15.20±0.21) and (14.70±0.17) ng/mg. The residual DNA in the experimental group was significantly lower than that in the control group (=－13.41, <0.01) and positive control group (=－11.30, <0.01). HE staining results showed that multiple bone formation centers with active osteogenesis and rich bone marrow were observed in experimental group 4 weeks after implantation, but only a small number of bone formation centers were observed in the control and positive control groups, with no obvious osteoblasts present. Immunohistochemistry results indicated that the expressions of alkaline phosphatase, Runt-related transcription factor 2, collagen typeⅠand osteocalcin in the experimental group showed an increasing trend compared with those in the control and positive control groups. Compared with clinically used allogenic demineralized bone matrix and bone graft material decellularized with conventional method, bone graft material decellularized with supercritical carbon dioxide exhibits lower immunogenicity and better osteogenic ability.
Glycosylation modification serves as a pivotal quality attribute in glycoprotein-based therapeutics, emphasizing its role in drug safety and efficacy. Prior studies have underscored the potential immunogenic risks posed by the presence of galactose-α-1,3-galactose (α-Gal) and N-glycolylneuraminic acid (NeuGc) in glycoprotein formulations. This accentuates the imperative for developing robust qualitative and quantitative analytical methods to monitor these immunogenic epitopes, thereby ensuring drug safety. In the present investigation, α-Gal and NeuGc were accurately quantified using UPLC-FLR-MS/MS at the oligosaccharide level. Remarkably, α-Gal could be identified when the ion intensity ratio or the mass-to-charge ratio (m/z) of 528.19 to 366.14 exceeded 1. Concurrently, NeuGc and N-acetylneuraminic acid (NeuAc) could be unambiguously identified through their respective fragment ions at m/z 673.23 and m/z 657.23. Furthermore, relative quantification of α-Gal and NeuGc was achieved using fluorescence signals. This study introduces a sensitive and reliable analytical approach for the qualitative and quantitative assessment of α-Gal and NeuGc in glycoprotein pharmaceuticals. The methodology offers significant potential for application in process control and optimization of glycoprotein production, aimed at minimizing immunogenicity and enhancing product quality.
A Raffinose family oligosaccharides (RFOs) is one of the major translocated sugars in the vascular bundle of cucumber, but little RFOs can be detected in fruits. Alpha-galactosidases (α-Gals) catalyze the first catabolism step of RFOs. Six α-Gal genes exist in a cucumber genome, but their spatial functions in fruits remain unclear. Here, we found that RFOs were highly accumulated in vascular tissues. In phloem sap, the stachyose and raffinose content was gradually decreased, whereas the content of sucrose, glucose and fructose was increased from pedicel to fruit top. Three alkaline forms instead of acid forms of were preferentially expressed in fruit vascular tissues and alkaline forms have stronger RFO-hydrolysing activity than acid forms. By inducible gene silencing of three alkaline forms of , stachyose was highly accumulated in RNAi- plants, while raffinose and stachyose were highly accumulated in RNAi- plants. The content of sucrose, glucose and fructose was decreased in both RNAi- and RNAi- plants after β-estradiol treatment. In addition, the fresh- and dry-weight of fruits were significantly decreased in RNAi- and RNAi- plants. In cucurbitaceous plants, the non-sweet motif within the promoter of is widely distributed in the promoter of its homologous genes. Taken together, we found RFOs hydrolysis occurred in the vascular tissues of fruits. and played key but partly distinct roles in the hydrolysis of RFOs.