Biology subjects

Jung, S. H.

Publications and source records attributed to Jung, S. H..

6 recordsLinked to original sources

bioRxiv2026

Proteomic Profiling Identifies CLDN3 as a Tumor-Selective Therapeutic Target in Small Cell Lung Cancer

Small cell lung cancer (SCLC) remains a highly lethal disease with limited targetable surface antigens beyond delta-like ligand 3 (DLL3). We sought to systematically identify and validate tumor-selective cell-surface targets in relapsed SCLC. To this end, we developed an integrated proteogenomic pipeline combining single-cell RNA sequencing, combinatorial optimization, mass spectrometry-based proteomics, and immunohistochemistry to systematically map the SCLC surfaceome of 49 tumors across 25 patients with relapsed SCLC. Using this approach we found claudin-3 (CLDN3) to be a consistently expressed and tumor-selective antigen, with broader coverage than DLL3, which is the current clinical benchmark. CLDN3 was highly expressed across various treatment states, while maintaining low expression in most nonmalignant tissues. Functional validation using a novel CLDN3-specific monoclonal antibody (ABN501) demonstrated NK cell-mediated cytotoxicity in vitro and tumor regression in vivo, as well as a favorable safety profile. These findings support clinical development of CLDN3-directed therapies and demonstrate the utility of integrated proteogenomic approaches for antigen discovery in solid tumors.

cancer biology↗

bioRxiv2025

Cinnamomum cassia Extract and Its Novel Isolated Compound Suppress Inflammation via Autophagy Induction in Sepsis

Uncontrolled inflammation is central to the development of diseases such as sepsis, and autophagy has emerged as a critical regulatory mechanism in this process. The ethanol extract of Cinnamomum cassia (EECC) was identified as a potent autophagy inducer through high-throughput LC3 reporter screening. EECC enhanced autophagic flux, as confirmed by RFP-GFP-LC3 imaging and immunoblotting. It also suppressed Toll-like receptor signaling and reduced pro-inflammatory cytokine production in macrophages. EECC inhibited nuclear factor-{kappa}B signaling in an autophagy-dependent manner, as this effect was reversed by autophagy inhibitors. To identify active constituents, 24 compounds were isolated from EECC, including six novel structures. Among the novel compounds, Cassitamine F exhibited dual activity as an autophagy inducer and inflammation suppressor. In a lipopolysaccharide-induced sepsis model, Cassitamine F significantly reduced serum levels of pro-inflammatory cytokines. These findings suggest that EECC and Cassitamine F may hold therapeutic potential for autophagy-targeted treatment of sepsis and other inflammation-related disorders. Highlights- Ethanol extract of Cinnamomum cassia (EECC) identified as a potent autophagy inducer via high-throughput LC3 HiBiT screening. - EECC suppresses Toll-like receptor signaling and pro-inflammatory cytokines through autophagy-dependent pathways. - Twenty-four compounds were isolated from EECC, including six novel structures (Cassitamine A-F). - Cassitamine F exhibits dual activity: induction of autophagy and inhibition of inflammation. - Cassitamine F significantly reduces serum cytokine levels in an LPS-induced sepsis model, suggesting therapeutic potential.

pharmacology and toxicology↗

bioRxiv2024

PAM-flexible adenine base editing rescues hearing loss in a humanized MPZL2 mouse model harboring an East Asian founder mutation

Hearing loss is one of the most prevalent sensory disorders, but no commercial biological treatments are currently available. Here, we identified an East Asia-specific founder mutation, the homozygous c.220C>T mutation in MPZL2, that contributes to a significant proportion of hereditary deafness cases in our cohort study. We found that the disease-causing mutation could be targetable by adenine base editors (ABEs) that enable A{middle dot}T-to-G{middle dot}C base corrections without DNA double-strand breaks. To demonstrate this, we developed a humanized mouse model (hMPZL2Q74X/Q74X) that recapitulates human MPZL2 deafness and leads to progressive hearing loss. A PAM-flexible ABE variant with reduced bystander and off-target effects (ABE8eWQ-SpRY:sgRNA3) was packaged in dual adeno-associated viruses (AAVs) and injected into the inner ear of hMPZL2Q74X/Q74X mice and effectively corrected the mutation. This treatment significantly restored hearing function, improved inner ear structural integrity, and reversed altered gene expression. Base editing may hold therapeutic potential for hereditary deafness, including most cases of MPZL2 deafness.

genetics↗

bioRxiv2024

A high-throughput search for intracellular factors that affect RNA folding identifies E. coli proteins PepA and YagL as RNA chaperones that promote RNA remodeling

General RNA chaperones are RNA-binding proteins (RBPs) that interact transiently and non-specifically with RNA substrates and assist in their folding into native state. In bacteria, these chaperones impact both coding and non-coding RNAs and are particularly important for large, structured RNAs which are prone to becoming kinetically trapped in misfolded states. Currently, due to the limited number of well-characterized examples and the lack of a consensus structural or sequence motif, it is difficult to identify general RNA chaperones in bacteria. Here, we adapted a previously published in vivo RNA regional accessibility probing assay to screen genome wide for intracellular factors in E. coli affecting RNA folding, among which we aimed to uncover novel RNA chaperones. Through this method, we identified and validated eight proteins whose deletion gives changes in regional accessibility within the exogenously expressed Tetrahymena group I intron ribozyme. Further, we purified and measured in vitro properties of two of these proteins, YagL and PepA, which were especially attractive as general chaperone candidates. We showed that both proteins bind RNA and that YagL accelerates native refolding of the ribozyme from a long-lived misfolded state. Further dissection of YagL showed that a putative helix-turn-helix (HTH) domain is responsible for most of its RNA binding activity but only the full protein shows chaperone activity. Altogether, this work expands the current repertoire of known general RNA chaperones in bacteria.

molecular biology↗

bioRxiv2024

Massively parallel screening of TIR-derived peptides reveals vast TLR-targeting immunomodulatory peptides

Toll-like receptors (TLRs) are critical regulators of the immune system, and altered TLR responses lead to a variety of inflammatory diseases. Interference of intracellular TLR signaling, which is mediated by multiple Toll/interleukin-1 receptor (TIR) domains on all TLRs and TLR adapters, is an effective therapeutic strategy against immune dysregulation. Peptides that inhibit TIR-TIR interactions by fragmenting interface residues have potential as therapeutic decoys. However, a systematic method for discovering TIR-targeting moieties has been elusive, limiting exploration of the vast unsequenced space of the TIR domain family. Here, we developed a comprehensive parallel screening method to uncover novel TIR-binding peptides derived from previously unexplored surfaces on a wide range of TIR domains. We constructed a large peptide library, named TIR surfacesome, by tiling surface sequences of the large TIR domain family and screening against MALTIR and MyD88TIR, TIRs of two major TLR adaptor proteins, resulting in the discovery of hundreds of TIR-binding peptides. The selected peptides inhibited TLR signaling, demonstrated anti-inflammatory effects in macrophages and therapeutic potential in mouse inflammatory models. This approach may facilitate the development of TLR-targeted therapeutics.

molecular biology↗

bioRxiv2016

Parkin knockout inhibits neuronal development via regulation of proteasomal degradation of p21

PARK2 encodes for the E3 ubiquitin ligase parkin and iimplicates in the development of Parkinsons disease (PD). Although the neuroprotective role of parkin is well known, the mechanism of parkins function in neural stem differentiation is not clear. Co-expressions network analysis showed that SNAP25 and BDNF were positively correlated with parkin, but negatively correlated with p21 in human patient brain. Therefore, we investigated a link between the ubiquitin E3 ligase parkin and proteasomal degradation of p21 for the control of neural stem cell differentiation. We discovered that p21 directly binds with parkin and is ubiquitinated by parkin resulting in the loss of cell differentiation ability. Tranfection of p21 shRNA in PARK2 KO mice significantly rescued the differentiation efficacy as well as SNAP25 and BDNF expression. We also defined the decreased p21 ubiquitination and differentiation ability were reversed after treatment with JNK inhibitor, SP600125 in PARK2 KO mice derived neural stem cells. Thus, the present study indicated that parkin knockout inhibits neural stem cell differentiation by JNK-dependent proteasomal degradation of p21.\n\nSummary statementThe present study indicated that parkin knockout inhibits neural stem cell differentiation by JNK-dependent proteasomal degradation of p21.

cell biology↗