Biology subjects

Zheng, W. S.

Publications and source records attributed to Zheng, W. S..

6 recordsLinked to original sources

bioRxiv2026

Sperm development requires TMC5-dependent mechanoresponsive calcium entry

Spermiogenesis, the transformation of round spermatids into streamlined, fertilization-competent sperm, represents cellular morphogenesis at its most extreme. Despite decades of effort, spermiogenesis remains difficult to recapitulate outside the testis, highlighting the importance of cues within the native tissue environment. The nature of these cues, however, remains poorly understood. Here, we discover that mechanical stimulation elicits Ca2+ entry in spermatids and identify transmembrane channel-like protein 5 (TMC5) as a principal mediator of this response. In both mouse and human testes, TMC5 is selectively expressed in spermatids and localized to the plasma membrane. TMC5 associates with TMC7 and calcium- and integrin-binding (CIB) proteins, mirroring TMC-CIB mechanotransduction complexes in sensory organs. Mechanistically, loss of Tmc5 blocks mechanically evoked Ca2+ entry, leading to disruptions in cytoskeletal remodeling and failure of CREM [&tau] dependent transcriptional programs required for spermiogenesis. Thus, TMC5 is required to couple mechanical cues to sperm development, with direct implications for male infertility.

cell biology↗

bioRxiv2024

Tear secretion via a paracellular pathway in lacrimal gland is regulated by myosin-mediated modulation of tight junction permeability

"Dry eye", characterized by symptoms of ocular discomfort and visual disturbances due to decreased tear secretion, affects 16 million Americans. Yet, there is currently no cure for dry eye as the mechanistic details of water secretion in the tear-producing lacrimal gland have not been fully elucidated. While a transcellular water secretion pathway via water channels like AQP5 has been reported, the existence and function of a paracellular pathway via tight junctions between epithelial cells remains controversial. The actomyosin cytoskeleton localizes to the apical junctions of epithelial cells across organs and regulates tight junction integrity. Here, we report that non-muscle myosin IIC (NMIIC) is enriched at apical junctions of ductal epithelial cells in the lacrimal gland, leading us to hypothesize that NMIIC regulates tear secretion through modulation of tight junction permeability. Consistent with this hypothesis, we found that tear volume after carbachol stimulation was significantly increased in mice lacking NMIIC, and levels of the tight junction protein ZO-1 were significantly reduced. Furthermore, pharmacological activation of NMIIC by 4-Hydroxyacetophenone in wildtype mice significantly inhibited tear secretion. In summary, our findings reveal a paracellular water secretion pathway in the lacrimal gland, which is regulated by NMIIC-mediated modulation of ductal cell tight junctional permeability, and can be targeted by small molecules. Significance StatementWhile dry eye affects more than 16 million Americans, there is currently no cure as the mechanisms underlying tear secretion are incompletely understood. Here, we report first evidence for the existence and function of a paracellular water pathway, in which water flows between cells, in the lacrimal gland. We also show that this pathway is directly regulated by the modulation of tight junction permeability by non-muscle myosin IIC (NMIIC). This study thus identifies a new mechanism for exocrine secretion, which can be targeted towards developing treatments for dry eye/mouth syndrome.

physiology↗

bioRxiv2024

Transmembrane channel-like 4 and 5 proteins at microvillar tips are potential ion channels and lipid scramblases

Microvilli--membrane bound actin protrusions on the surface of epithelial cells--are sites of critical processes including absorption, secretion, and adhesion. Increasing evidence suggests microvilli are mechanosensitive, but underlying molecules and mechanisms remain unknown. Here, we localize transmembrane channel-like proteins 4 and 5 (TMC4 and 5) and calcium and integrin binding protein 3 (CIB3) to microvillar tips in intestinal epithelial cells, near glycocalyx insertion sites. We find that TMC5 colocalizes with CIB3 in cultured cells and that a TMC5 fragment forms a complex with CIB3 in vitro. Homology and AlphaFold2 models reveal a putative ion permeation pathway in TMC4 and 5, and molecular dynamics simulations predict both proteins can conduct ions and perform lipid scrambling. These findings raise the possibility that TMC4 and 5 interact with CIB3 at microvillar tips to form a mechanosensitive complex, akin to TMC1 and 2, and CIB2 and 3, within the mechanotransduction channel complex at the tips of inner ear stereocilia.

cell biology↗

bioRxiv2022

GESIAP: A Versatile Genetically Encoded Sensor-based Image Analysis Program

Intercellular communication mediated by a large number of neuromodulators diversifies physiological actions, yet neuromodulation remains poorly understood despite the recent upsurge of genetically encoded transmitter sensors. Here, we report the development of a versatile genetically encoded sensor-based image analysis program (GESIAP) that utilizes MATLAB-based algorithms to achieve high-throughput, high-resolution processing of sensor-based functional imaging data. GESIAP enables delineation of fundamental properties (e.g., transmitter spatial diffusion extent, quantal size, quantal content, release probability, pool size, and refilling rate at single release sites) of transmission mediated by various transmitters (i.e., monoamines, acetylcholine, neuropeptides, and glutamate) at various cell types (i.e., neurons, astrocytes, and other non-neuronal cells) of various animal species (i.e., mouse, rat, and human). Our analysis appraises a dozen of newly developed transmitter sensors, validates a conserved model of restricted non-volume neuromodulatory synaptic transmission, and accentuates a broad spectrum of presynaptic release properties that variegate neuromodulation.

neuroscience↗

bioRxiv2020

Guiding oligodendrocyte precursor cell maturation with urokinase plasminogen activator-degradable elastin-like protein hydrogels

Demyelinating injuries and diseases, like multiple sclerosis, affect millions of people worldwide. Oligodendrocyte precursor cells (OPCs) have the potential to repair demyelinated tissue because they can both self-renew and differentiate into oligodendrocytes (OLs), the myelin producing cells of the central nervous system (CNS). Cell-matrix interactions impact OPC differentiation into OLs, but the process is not fully understood. Biomaterial hydrogel systems help to elucidate cell-matrix interactions because they can mimic specific properties of native CNS tissue in an in vitro setting. We investigated whether OPC maturation into OLs is influenced by interacting with a urokinase plasminogen activator (uPA) degradable extracellular matrix (ECM). uPA is a proteolytic enzyme that is transiently upregulated in the developing rat brain, with peak uPA expression correlating with an increase in myelin production in vivo. OPC-like cells isolated through the Mosaic Analysis with Double Marker technique (MADM OPCs) produced low molecular weight uPA in culture. MADM OPCs were encapsulated into two otherwise similar elastin-like protein (ELP) hydrogel systems: one that was uPA degradable and one that was non-degradable. Encapsulated MADM OPCs had similar viability, proliferation, and metabolic activity in uPA degradable and non-degradable ELP hydrogels. Expression of OPC maturation-associated genes, however, indicated that uPA degradable ELP hydrogels promoted MADM OPC maturation although not sufficiently for these cells to differentiate into OLs. Graphical Abstract - For table of contents only O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=86 SRC="FIGDIR/small/224899v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@4f3356org.highwire.dtl.DTLVardef@1b369d4org.highwire.dtl.DTLVardef@1e8df31org.highwire.dtl.DTLVardef@1954777_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2020

A fast genetically encoded fluorescent sensor for faithful in vivo acetylcholine detection in mice, fish, worms and flies

Here we design and optimize a genetically encoded fluorescent indicator, iAChSnFR, for the ubiquitous neurotransmitter acetylcholine, based on a bacterial periplasmic binding protein. iAChSnFR shows large fluorescence changes, rapid rise and decay kinetics, and insensitivity to most cholinergic drugs. iAChSnFR revealed large transients in a variety of slice and in vivo preparations in mouse, fish, fly and worm. iAChSnFR will be useful for the study of acetylcholine in all animals.

neuroscience↗