Biology subjects

Lin, J. H.

Publications and source records attributed to Lin, J. H..

4 recordsLinked to original sources

bioRxiv2026

Atf6-/- mouse photoreceptors exhibit novel ciliary rootlet defect

ATF6 is a regulator of the Unfolded Protein Response that maintains cellular homeostasis during ER stress. In patients, ATF6 mutations cause photoreceptor dystrophy and sensorineural hearing loss. Atf6-/- mice develop progressive hearing loss with stereocilia disorganization and mild retinal dysfunction, suggesting that ATF6 loss may impair the structural integrity of sensory cells. To test this possibility, we analyzed the retinal ultrastructure of Atf6-/- mouse photoreceptors using transmission electron microscopy and identified a novel defect in which the ciliary rootlet is unbundled, disorganized, and possibly detached from the basal body. These findings demonstrate that ATF6 is essential for maintaining the structural organization of the photoreceptor ciliary apparatus, linking ER proteostasis to cytoskeletal integrity and providing a potential mechanistic basis for the progressive degeneration of photoreceptor outer segments and stereocilia observed in ATF6-deficient patients.

cell biology↗

bioRxiv2025

Common Gene Networks Orchestrate Organelle Architecture and Inter-Organelle Metabolic Flows for Mucin Production in High Endothelial and Goblet Cells

High endothelial cells (HECs) are specialized vascular gatekeepers that control lymphocyte entry into lymph nodes, a process essential for immune surveillance and adaptive responses. However, how HECs coordinate their high biosynthetic demands with the secretory apparatus to support immune function remains unclear. Using multi-omic approaches, we identify IRE1-XBP1-centered transcriptional networks that, together with CREB3L2-associated gene programs, coordinate inter-organelle metabolic and secretory pathways required for glycosylation and assembly of peripheral node addressin (PNAd), a sulfated sialomucin critical for lymphocyte homing. Genetic or pharmacological perturbation of these pathways disrupts HEC morphology and lymphocyte recruitment during homeostasis and impairs HEC induction during inflammation. Parallel transcriptional programs operate in mucin-producing intestinal goblet cells, suggesting common regulatory pathways linking metabolism and sulfated mucin specialization with the associated expansion of secretory organelles across immune and barrier tissues. Thus, our findings identify transcriptional programs that coordinately scale metabolic pathways and secretory organelles to support the biosynthetic infrastructure underlying the morphology and immune trafficking functions of HEVs. Key pointsXBP1-centered transcriptional networks coordinate metabolic and secretory programs for PNAd biosynthesis. IRE1 or S1P inhibition flattens HEVs, prevents ectopic HEV formation and, reduces lymphocyte recruitment Endothelial XBP1 deletion disrupts HEV morphology and lymphocyte trafficking. Goblet cells share secretory transcriptional programs and regulatory logic with HEV.

immunology↗

bioRxiv2022

Neurodegeneration Risk Factor, EIF2AK3 (PERK), Influences Tau Protein Aggregation

Tauopathies are neurodegenerative diseases caused by pathologic misfolded tau protein aggregation in the nervous system. Population studies implicate EIF2AK3 (eukaryotic translation initiation factor 2 alpha kinase 3), better known as PERK (protein kinase R-like endoplasmic reticulum kinase), as a genetic risk factor in several tauopathies. PERK is a key regulator of intracellular proteostatic mechanisms - Unfolded Protein Response (UPR) and Integrated Stress Response (ISR). Previous studies found that tauopathy-associated PERK variants encoded functional hypomorphs with reduced signaling in vitro. But, it remained unclear how altered PERK activity led to tauopathy. Here, we chemically or genetically modulated PERK signaling in cell culture models of tau aggregation and found that PERK pathway activation prevented tau aggregation while inhibition exacerbated tau aggregation. In primary tauopathy patient brain tissues, we found that reduced PERK signaling correlated with increased tau neuropathology. We found that tauopathy-associated PERK variants targeted the ER luminal domain; and two of these variants damaged hydrogen bond formation. Our studies support that PERK activity protects against tau aggregation and pathology. This may explain why people carrying hypomorphic PERK variants have increased risk for developing tauopathies. Finally, our studies identify small molecule augmentation of PERK signaling as an attractive therapeutic strategy to treat tauopathies by preventing tau pathology.

neuroscience↗

bioRxiv2021

Type II alveolar cells with constitutive expression of MHCII and limited antigen presentation capacity contribute to improved respiratory viral disease outcomes

Type II alveolar cells (AT2s) are critical for basic respiratory homeostasis and tissue repair after lung injury. Prior studies indicate that AT2s also express major histocompatibility complex II (MHCII) molecules, but how MHCII expression by AT2s is regulated and how it contributes to host defense remain unclear. Here we show that AT2s express high levels of MHCII independent of conventional inflammatory stimuli, and that selective loss of MHCII from AT2s in mice results in the worsening of respiratory virus disease following influenza and Sendai virus infections. We also find that AT2s exhibit MHCII presentation capacity that is substantially limited in comparison to professional antigen presenting cells. The combination of constitutive MHCII expression and restrained presentation may position AT2s to contribute to lung adaptive immune responses in a measured fashion, without over-amplifying damaging inflammation.

immunology↗