Biology subjects

Jung, A. L.

Publications and source records attributed to Jung, A. L..

5 recordsLinked to original sources

bioRxiv2026

Lifespan Analysis of the Lung Epithelium Reveals Inflammatory Reprogramming and Regenerative Decline

Aging is a major risk factor for chronic lung diseases, associated with chronic low-grade inflammation (inflammaging) and impaired epithelial regeneration. How epithelial-intrinsic aging intersects with inflammaging across the lifespan remains poorly understood. Here, we systematically analyzed lung epithelial cells from neonatal, young adult, and aged mice to define age-dependent changes in regenerative capacity. RNA sequencing revealed lifespan-associated shifts characterized by early repression of developmental and WNT/{beta}-catenin programs and progressive activation of DNA damage, inflammation, and senescence signatures. Functionally, neonatal epithelial cells exhibited markedly enhanced organoid-forming capacity compared with young and aged cells. Aged organoids maintained a pro-inflammatory secretory profile indicative of cell-intrinsic inflammaging, and transfer of the aged secretome or TNF- to young cultures significantly impaired regeneration. Comparison of freshly isolated cells and long-term organoid cultures revealed sustained repression of regenerative pathways with age, consistent with stable epigenetic imprinting. Pharmacological inhibition of DNA methylation and WNT signalling partially restored regenerative capacity in adult organoids. Together, these findings identify epigenetic reprogramming and epithelial-intrinsic inflammaging as key determinants of age-dependent regenerative decline.

cell biology↗

bioRxiv2025

Functional Mapping and Engineering of the Sec Translocon Unlocked by a Cell-Free System

Almost all proteins are inserted or translocated across membranes by the universally conserved Sec translocon. Despite its central role, experimental access to Sec function has remained limited. Here, we present a cell-free protein synthesis platform that inserts SecYEG into synthetic vesicles, enabling direct testing of Sec in real-time and high-throughput, circumventing longstanding viability constraints. Screening 300 Sec variants in a single experiment, we consolidate three decades of Sec research, while vastly expanding mutant diversity for structure-function insights. Mapping over 30 functionally critical regions that modulate Sec activity across three orders of magnitude, we uncover dozens of super-active variants. We further leverage our system to increase membrane protein quality and nanobody export, highlighting the potential of our system for advancing applications in synthetic biology and biotechnology.

molecular biology↗

bioRxiv2025

Engineering site-specific nucleic acid-protein conjugates by utilizing a natural RNAylation reaction

Nucleic acid-protein conjugates are valuable for synthetic biology, therapeutics, and nanotechnology, but current methods often lack site specificity and rely on non-natural linkages. RNAylation, a one-step enzymatic reaction catalyzed by the bacteriophage T4 enzyme ModB where first discovered in vivo during phage infection, enables site-specific conjugation of nucleic acids to proteins via a natural N-glycosidic bond. Here, we establish RNAylation as a novel and robust in vitro platform for generating nucleic acid-protein conjugates, overcoming key limitations of existing strategies. We define design principles for this approach, demonstrate enhanced nucleic acid stability in human cell lysates, and develop an efficient purification workflow. Furthermore, we achieve successful delivery of purified conjugates into human cells, highlighting the potential for functional in vivo applications. Our work expands RNAylation from a phage-specific phenomenon to a versatile, biologically relevant strategy with broad biotechnological potential.

bioengineering↗

bioRxiv2023

NAD+ metabolism is a key modulator of bacterial respiratory epithelial infections

1.Lower respiratory tract infections caused by StreptococcusOpneumoniae (Spn) are a leading cause of death globally. Here we investigate the bronchial epithelial response to Spn infection on a transcriptomic, proteomic and metabolic level. We found the NAD+ salvage pathway to be dysregulated upon infection in a cell line model, primary human lung tissue and in vivo in rodents, leading to a reduced production of NAD+. Knockdown of NAD+ salvage enzymes (NAMPT, NMNAT1) increased bacterial replication. NAD+ treatment of Spn inhibited its growth while growth of other respiratory pathogens improved. Boosting NAD+ production increased NAD+ levels in immortalized and primary cells and decreased bacterial replication upon infection. NAD+ treatment of Spn dysregulated the bacterial metabolism and reduced intrabacterial ATP. Enhancing the bacterial ATP metabolism abolished the antibacterial effect of NAD+. Thus, we identified the NAD+ salvage pathway as an antibacterial cascade in Spn infections, predicting a novel antibacterial mechanism of NAD+.

immunology↗

bioRxiv2022

Cell-free biosynthesis combined with deep learning accelerates de novo-development of antimicrobial peptides

Bioactive peptides are key molecules in health and medicine. Deep learning holds a big promise for the discovery and design of bioactive peptides. Yet, suitable experimental approaches are required to validate candidates in high throughput and at low cost. Here, we established a cell- free protein synthesis (CFPS) pipeline for the rapid and inexpensive production of antimicrobial peptides (AMPs) directly from DNA templates. To validate our platform, we used deep learning to design thousands of AMPs de novo. Using computational methods, we prioritized 500 candidates that we produced and screened with our CFPS pipeline. We identified 30 functional AMPs, which we characterized further through molecular dynamics simulations, antimicrobial activity and toxicity. Notably, six de novo-AMPs feature broad-spectrum activity against multidrug-resistant pathogens and do not develop bacterial resistance. Our work demonstrates the potential of CFPS for production and testing of bioactive peptides within less than 24 hours and <10$ per screen.

synthetic biology↗