Biology subjects

wu, z.

Publications and source records attributed to wu, z..

4 recordsLinked to original sources

bioRxiv2025

N-Glycan Fingerprinting of the NIST monoclonal antibody (NISTmAb)

Glycosylation on therapeutic antibodies is critically important for their drug efficacies. Here, using NISTmAb and Humira(R) as examples, we present methods of glycan fingerprinting for these antibodies. Glycans are first released with PNGase F or Endo S2, and then labeled by specific glycosyltransferases, including sialyltransferase ST6Gal1, fucosyltransferase FUT9, N-acetyl-glucosaminyltransferase MGAT3 and fucosyltransferase FUT8, with respective fluorophore-conjugated donor sugars. The labeled glycans are then separated by gel electrophoresis (SDS-PAGE). A fluorophore-labeled hyaluronan ladder is run along with the samples to reveal the relative mobility of each glycan band. Pretreatment of the samples with specific glycosidase or glycosyltransferase results in additional mobility shift of specific glycan bands, which allows identification of some of these bands. Particularly, we report the identification of -Gal epitopes, core-6 fucosylated glycans, paucimannose glycans and likely some bisecting/tri-antennary glycans on NISTmAb. Overall, our methods could serve as quick assessments of glycosylation on therapeutic antibodies.

molecular biology↗

bioRxiv2025

The Role of Microglia and Complement C5/C5a in the Pathogenesis of Rhegmatogenous Retinal Detachment with Choroidal Detachment

BackgroundRhegmatogenous retinal detachment with choroidal detachment (RRDCD) is an uncommon and sight-threatening disorder marked by fast development and significant inflammation. This study aimed to identify cellular and molecular signatures distinguishing RRDCD from typical rhegmatogenous retinal detachment (RRD) and to investigate the roles of microglia and the complement C5/C5a pathway in disease pathogenesis. MethodsSingle-cell RNA sequencing (scRNA-seq) was employed to analyze vitreous samples from patients with RRD and RRDCD, indicating its involvement in blood-retina barrier impairment. ResultsOur findings revealed a distinct cellular landscape in RRDCD, characterized by enhanced connectivity between microglia and dendritic cells, alongside a significant upregulation of the complement C5-C5AR1 interaction. In vitro experiments indicated that treatment with complement C5 promoted microglial proliferation and activation, induced apoptosis in RF/6A endothelial cells, and disrupted tight junctions in ARPE-19 epithelial cells, suggesting a role in blood-retina barrier dysfunction. ConclusionThe findings substantiate the inflammatory hypothesis regarding the pathogenesis of RRDCD, emphasizing the critical functions of microglia and the complement C5/C5a pathway in intensifying retinal inflammation and undermining vascular integrity.

bioinformatics↗

bioRxiv2024

Osterix Facilitates Osteocytic Communication by Targeting Connexin43

Osteocytes, terminal-differentiated cells in bone, are now considered as more pivotal regulators of mature bone homeostasis than other bone cells, since they constitute 90- 95% of the bone cell population. Given their non-migratory nature within the mineralized matrix, their unique dendrites are crucial for cell-to-cell communication in response to both intracellular and extracellular stimuli, such as bone fracture or mechanical load. Here, we showed that Osterix (Osx), usually recognized as a specific doorkeeper for osteoblast differentiation during new bone formation marked by collagen type I 1 (Col11), was unexpectedly co-expressed with Col11 in osteocytes within the cortical bone of mice. Deleting Osx in Col11-positive osteocytes disrupted cortical bone structure and osteocytic dendrites in mice, thus impairing transcellular fluid flow and intercellular communication. Conversely, overexpression of Osx in osteocytes enhanced these processes. Furthermore, we identified Connexin43, a critical protein of gap junction channel, was a direct transcriptional target of Osx in regulating dendrites of osteocytes. Pharmacological restoration of Connexin43 levels rescued the dysfunction in Osx-deficient osteocytes both in vitro and in vivo. Taken together, this work demonstrated Osxs distinct role in osteocyte function through maintaining intercellular signaling, which broadened the current understanding of its role in Col11-positive bone cells, extending beyond osteoblasts and bone mineralization, offering new insights into bone diseases such as fracture nonunion or disuse osteoporosis.

cell biology↗

bioRxiv2020

Caerulomycin and Collismycin Antibiotics Share a trans Flavin-Dependent Assembly Line for 2,2-Bipyridine Formation and Sulfur Fate Differentiation

Linear nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) template the modular biosynthesis of numerous nonribosomal peptides, polyketides and their hybrids though assembly line chemistry. This chemistry can be complex and highly varied, and thus challenges the understanding in the diverse polymerization processes of amino acid and carboxylate monomers programmed by various NRPSs and PKSs in nature. Here, we report that caerulomycin and collismycin peptide-polyketide hybrid antibiotics share an unusual assembly line that involves NRPS activity to recruit a flavoprotein acting in trans and catalyze C-C bond formation and heterocyclization during 2,2-bipyridine formation. Simultaneously, this assembly line provides dethiolated and thiolated 2,2-bipyridine intermediates through differential treatment of the sulfhydryl group arising from L-cysteine incorporation. Subsequent L-leucine extension, which does not contribute any atoms to either caerulomycins or collismycins, plays a key role in sulfur fate determination by selectively advancing one of the two 2,2-bipyridine intermediates down a path to the final products with or without sulfur decoration. These findings further the appreciation of assembly line chemistry and will facilitate the development of related molecules using synthetic biology approaches.

biochemistry↗