define the cochlear sensory domain and regulate vestibular and cochlear sensory patterning in the mammalian inner ear.

The mammalian inner ear houses the vestibular and cochlear sensory organs dedicated to sensing balance and sound, respectively. These distinct sensory organs arise from a common prosensory region, but the mechanisms underlying their divergence remain elusive. Here, we showed that two evolutionarily conserved homeobox genes, and , are required for the patterning and segregation of the saccular and cochlear sensory domains, as well as for the formation of auditory sensory cells.

Nanobead-based single-molecule pulldown for single cells.

Investigation of cell-to-cell variability holds critical physiological and clinical implications. Thus, numerous new techniques have been developed for studying cell-to-cell variability, and these single-cell techniques can also be used to investigate rare cells. Moreover, for studying protein-protein interactions (PPIs) in single cells, several techniques have been developed based on the principle of the single-molecule pulldown (SiMPull) assay.

Novel marine natural products as effective TRPV1 channel blockers.

Chronic pain management poses a formidable challenge to healthcare, exacerbated by current analgesic options' limitations and adverse effects. Transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel, has emerged as a promising target for novel analgesics. However, safety and tolerability concerns have constrained the development of TRPV1 modulators.

Apicosome: Newly identified cell-type-specific organelle in mouse cochlear and vestibular hair cells.

Cochlear and vestibular hair cells are highly specialized sensory receptors for hearing and balance. Here, we report a serendipitous identification of a hair-cell-specific organelle in neonatal mouse inner ear, which we name "apicosome." The apicosome is ∼500 nm in diameter and shows itinerant nature and transient appearance during development in cochlear hair cells.

Analyzing protein-protein interactions in rare cells using microbead-based single-molecule pulldown assay.

For studying protein-protein interactions (PPIs) in general, a powerful and commonly used technique is conventional coimmunoprecipitation (co-IP/pulldown) followed by western blotting. However, the technique does not provide precise information regarding the kinetics and stoichiometry of PPIs. Another drawback is that the sensitivity of conventional co-IP is not suitable for examining PPIs in rare cells such as sensory hair cells, circulating tumor cells, embryonic stem cells, and subsets of immune cells.

Opposing roles of E3 ligases TRIM23 and TRIM21 in regulation of ion channel ANO1 protein levels.

Anoctamin-1 (ANO1) (TMEM16A) is a calcium-activated chloride channel that plays critical roles in diverse physiological processes, such as sensory transduction and epithelial secretion. ANO1 levels have been shown to be altered under physiological and pathological conditions, although the molecular mechanisms that control ANO1 protein levels remain unclear. The ubiquitin-proteasome system is known to regulate the levels of numerous ion channels, but little information is available regarding whether and how ubiquitination regulates levels of ANO1.

Alternative Splicing of Three Genes Encoding Mechanotransduction-Complex Proteins in Auditory Hair Cells.

The mechanotransduction (MT) complex in auditory hair cells converts the mechanical stimulation of sound waves into neural signals. Recently, the MT complex has been suggested to contain at least four distinct integral membrane proteins: protocadherin 15 (PCDH15), transmembrane channel-like protein 1 (TMC1), lipoma HMGIC fusion partner-like 5 (LHFPL5), and transmembrane inner ear protein (TMIE). However, the composition, function, and regulation of the MT-complex proteins remain incompletely investigated.

Deafness mutation D572N of TMC1 destabilizes TMC1 expression by disrupting LHFPL5 binding.

Transmembrane channel-like protein 1 (TMC1) and lipoma HMGIC fusion partner-like 5 (LHFPL5) are recognized as two critical components of the mechanotransduction complex in inner-ear hair cells. However, the physical and functional interactions of TMC1 and LHFPL5 remain largely unexplored. We examined the interaction between TMC1 and LHFPL5 by using multiple approaches, including our recently developed ultrasensitive microbead-based single-molecule pulldown (SiMPull) assay.

CFTR is a negative regulator of γδ T cell IFN-γ production and antitumor immunity.

CFTR, a chloride channel and ion channel regulator studied mostly in epithelial cells, has been reported to participate in immune regulation and likely affect the risk of cancer development. However, little is known about the effects of CFTR on the differentiation and function of γδ T cells. In this study, we observed that CFTR was functionally expressed on the cell surface of γδ T cells.

TMC1 is an essential component of a leak channel that modulates tonotopy and excitability of auditory hair cells in mice.

Hearing sensation relies on the mechano-electrical transducer (MET) channel of cochlear hair cells, in which transmembrane channel-like 1 (TMC1) and transmembrane channel-like 2 (TMC2) have been proposed to be the pore-forming subunits in mammals. TMCs were also found to regulate biological processes other than MET in invertebrates, ranging from sensations to motor function. However, whether TMCs have a non-MET role remains elusive in mammals.

Localization of TMC1 and LHFPL5 in auditory hair cells in neonatal and adult mice.

The channel that governs mechanotransduction (MT) by hair cells in the inner ear has been investigated intensively for 4 decades, but its precise molecular composition remains enigmatic. Transmembrane channel-like protein 1 (TMC1) was recently identified as a component of the MT channel, and lipoma HMGIC fusion partner-like 5 (LHFPL5) is considered to be part of the MT complex and may functionally couple the tip link to the MT channel. As components of the MT complex, TMC1 and LHFPL5 are expected to localize at the lower end of the tip link in hair cells, a notion generally supported by previous studies on neonatal mice.

Surgery-free video-oculography in mouse models: enabling quantitative and short-interval longitudinal assessment of vestibular function.

Vestibulo-ocular reflex (VOR) responding to acceleration stimuli is originated from the vestibular apparatuses and thus widely used as an in vivo indicator of the vestibular function. We have developed a vestibular function testing (VFT) system that allows to evaluate VOR response with improved efficiency. The previously required surgical procedure has been avoided by using a newly designed animal-immobility setup.

The complex of TRIP-Br1 and XIAP ubiquitinates and degrades multiple adenylyl cyclase isoforms.

Adenylyl cyclases (ACs) generate cAMP, a second messenger of utmost importance that regulates a vast array of biological processes in all kingdoms of life. However, almost nothing is known about how AC activity is regulated through protein degradation mediated by ubiquitination or other mechanisms. Here, we show that transcriptional regulator interacting with the PHD-bromodomain 1 (TRIP-Br1, Sertad1), a newly identified protein with poorly characterized functions, acts as an adaptor that bridges the interaction of multiple AC isoforms with X-linked inhibitor of apoptosis protein (XIAP), a RING-domain E3 ubiquitin ligase.

Mechanical Characterization of Microengineered Epithelial Cysts by Using Atomic Force Microscopy.

Most organs contain interconnected tubular tissues that are one-cell-thick, polarized epithelial monolayers enclosing a fluid-filled lumen. Such tissue organization plays crucial roles in developmental and normal physiology, and the proper functioning of these tissues depends on their regulation by complex biochemical perturbations and equally important, but poorly understood, mechanical perturbations. In this study, by combining micropatterning techniques and atomic force microscopy, we developed a simple in vitro experimental platform for characterizing the mechanical properties of the MDCK II cyst, the simplest model of lumen-enclosing epithelial monolayers.

Adenosine A2B Receptor: From Cell Biology to Human Diseases.

Extracellular adenosine is a ubiquitous signaling molecule that modulates a wide array of biological processes. Recently, significant advances have been made in our understanding of A2B adenosine receptor (A2BAR). In this review, we first summarize some of the general characteristics of A2BAR, and then we describe the multiple binding partners of the receptor, such as newly identified α-actinin-1 and p105, and discuss how these associated proteins could modulate A2BAR's functions, including certain seemingly paradoxical functions of the receptor.

Actinin-1 binds to the C-terminus of A2B adenosine receptor (A2BAR) and enhances A2BAR cell-surface expression.

A2BAR (A2B adenosine receptor) has been implicated in several physiological conditions, such as allergic or inflammatory disorders, vasodilation, cell growth and epithelial electrolyte secretion. For mediating the protein-protein interactions of A2BAR, the receptor's C-terminus is recognized to be crucial. In the present study, we unexpectedly found that two point mutations in the A2BAR C-terminus (F297A and R298A) drastically impaired the expression of A2BAR protein by accelerating its degradation.

Mechanosensitivity of wild-type and G551D cystic fibrosis transmembrane conductance regulator (CFTR) controls regulatory volume decrease in simple epithelia.

Mutations of cystic fibrosis transmembrane conductance regulator (CFTR), an epithelial ligand-gated anion channel, are associated with the lethal genetic disease cystic fibrosis. The CFTR G551D mutation impairs ATP hydrolysis and thereby makes CFTR refractory to cAMP stimulation. Both wild-type (WT) and G551D CFTR have been implicated in regulatory volume decrease (RVD), but the underlying mechanism remains incompletely understood.

[The MRI appearances of laryngeal carcinoma invading postcricoid area].

Objective: By studying the MRI apperances of postcricoid area invaded by laryngeal carcinoma, to identify the characteristic appearances of the invaded postcricoid area and to provide information on the early detection of the lesions.

Method: Eighteen cases of MRI images of postcricoid area invaded by laryngeal carcinoma were included in this study. To find out the characteristic manifestation of the lesions, the destructions of surrounding structures and layers, and the invaded extent were observed.

In vitro epithelial organoid generation induced by substrate nanotopography.

The extracellular matrix (ECM) exhibits tissue-specific topography and composition and plays a crucial role in initiating the biochemical and biomechanical signaling required for organizing cells into distinct tissues during development. How single cells assemble into structures featuring specific shapes in response to external cues is poorly understood. We examined the effect of substrate nanotopography on the morphogenesis of several types of epithelial cells and found that in response to the topography, Calu-3 and MDCK-II cells formed organoids that closely resemble their morphology in vivo.

Cooperative control of blood compatibility and re-endothelialization by immobilized heparin and substrate topography.

A wide variety of environmental cues provided by the extracellular matrix, including biophysical and biochemical cues, are responsible for vascular cell behavior and function. In particular, substrate topography and surface chemistry have been shown to regulate blood and vascular compatibility individually. The combined impact of chemical and topographic cues on blood and vascular compatibility, and the interplay between these two types of cues, are subjects that are currently being explored.

Directing vascular cell selectivity and hemocompatibility on patterned platforms featuring variable topographic geometry and size.

It is great challenge to generate multifunctionality of vascular grafts and stents to enable vascular cell selectivity and improve hemocompatibility. Micro/nanopatterning of vascular implant surfaces for such multifunctionality is a direction to be explored. We developed a novel patterned platform featuring two typical geometries (groove and pillar) and six pattern sizes (0.

Modulation of protein adsorption, vascular cell selectivity and platelet adhesion by mussel-inspired surface functionalization.

A mussel-inspired surface functionalization of the polydopamine (PDA) coating has been demonstrated to be a promising strategy to ensure the biocompatibility of various biomaterials. To explore the multifunctionality of the PDA coating for vascular stents and elucidate the mechanisms by which the PDA coating modulates vascular cell behavior, this study examined the protein adsorption, the responses of endothelial cells (ECs) and smooth muscle cells (SMCs), and platelet adhesion to various PDA-coated surfaces synthesized at varied initial dopamine concentrations. Our results indicate that various PDA coatings present distinct and varied functionalities.

Organic electrochemical transistor array for recording transepithelial ion transport of human airway epithelial cells.

An organic electrochemical transistor array is integrated with human airway epithelial cells. This integration provides a novel method to couple transepithelial ion transport with electrical current. Activation and inhibition of transepithelial ion transport are readily detected with excellent time resolution.

Keratin K18 increases cystic fibrosis transmembrane conductance regulator (CFTR) surface expression by binding to its C-terminal hydrophobic patch.

Background: CFTR function is tightly regulated by many interacting proteins.

Results: Intermediate filament protein keratin 18 increases the cell surface expression of CFTR by interacting with the C-terminal hydrophobic patch of CFTR.

Conclusion: K18 controls the function of CFTR.

Microcapillary-assisted dielectrophoresis for single-particle positioning.

Here, we demonstrate microcapillary-assisted dielectrophoresis (μC-DEP), a new capability for precise positioning of particles or biological cells in applications such as dynamic assays. The method largely derives from a need to evade the challenges faced with hydrodynamic trapping of particles or cells at microcapillaries typically realized through brief application of suction. Microcapillaries here serve a dual purpose by firstly squeezing field lines to define localized positive DEP traps and then establishing an exclusive access to the trapped cell for probing.