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Wu, H.

Publications and source records attributed to Wu, H..

At least 91 records · Page 5Linked to original sources

Non-canonical signaling mechanisms of short-chain fatty acid receptors in glucagon-like peptide-1 (GLP-1) releasing enteroendocrine cells

ObjectivesFree fatty acid receptors 2 and 3 (FFA2 and FFA3) are activated by nutrient-derived metabolites such as short-chain fatty acids (SCFAs) and ketone bodies, produced by the gut microbiota and host, respectively. This study aimed to investigate the intracellular signaling pathways recruited in glucagon-like peptide-1 (GLP-1) releasing enteroendocrine cells following activation of FFA2 and FFA3 to resolve the impact of nutrient status on enteroendocrine cell function. MethodsExperiments were performed using primary mouse colonic cultures and the mouse enteroendocrine cell line, GLUTag cells. Expression analysis by bulk RNA sequencing was used to determine expression of FFA2 and FFA3 in GLP-1 releasing cells. Measurement of GLP-1 secretion by sandwich ELISA was used to assess enteroendocrine cell function. Live-cell measurements of intracellular calcium and cAMP levels were performed to assess canonical second messenger signaling pathways. ResultsA SCFA mixture stimulated GLP-1 secretion from both primary mouse colonic cultures and GLUTag cells. In GLUTag cells, the FFA2 ligand 4-CMTB inhibited GLP-1 release independent of Gaq- and Gai-signaling as neither YM-254890 (Gaq inhibitor) nor pertussis toxin (Gai- uncoupler) altered its effect. However, 4-CMTB did elevate cAMP levels, suggesting an indirect mechanism for the increase in cAMP production. Stimulation of FFA2 with the Gai-biased ligand AZ1729 or the ketone body acetoacetate inhibited GLP-1 release and cAMP accumulation. AZ1729 was insensitive to pertussis toxin and OZITX, supporting atypical FFA2 signaling. Stimulation of FFA3 with AR420626 or the ketone body {beta}-hydroxybutyrate increased GLP-1 secretion from GLUTag cells, an effect that was not mediated by cAMP production. AR420626, but not {beta}-hydroxybutyrate increased intracellular calcium levels. ConclusionsOverall, activation of FFA2 inhibited secretory function in GLP-1-releasing enteroendocrine cells, whereas activation of FFA3 stimulated GLP-1 secretion via distinct intracellular signaling mechanisms. O_FIG O_LINKSMALLFIG WIDTH=184 HEIGHT=200 SRC="FIGDIR/small/708924v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@175dbaforg.highwire.dtl.DTLVardef@a9cc3eorg.highwire.dtl.DTLVardef@1a026e5org.highwire.dtl.DTLVardef@15997af_HPS_FORMAT_FIGEXP M_FIG Graphical Abstract C_FIG HighlightsO_LIExposure to physiological levels of SCFAs stimulates GLP-1 secretion from colonic EECs C_LIO_LIFFA2 and FFA3 regulate GLP-1 release via non-canonical signaling pathways C_LIO_LIKetone bodies activate SCFA receptors to differentially modulate GLP-1 levels C_LIO_LILigand bias enables nutrient-dependent tuning of EEC gut hormone secretion C_LI

cell biology↗

The archaic CUP pilus SMF-1 uses an antiparallel bundling mechanism to initiate biofilm formation

Bacterial biofilms represent a survival strategy that enables microbial communities to withstand environmental stress. Stenotrophomonas maltophilia is an emerging, antibiotic-resistant, Gram-negative, opportunistic pathogen that frequently colonizes the lungs of individuals with cystic fibrosis. Its chaperone-usher pathway (CUP) pilus, SMF-1, is present in nearly all clinical isolates and is essential for biofilm development; however, its molecular architecture has remained unknown. Here, we present a 4.0 [A] cryo-EM structure revealing that SMF-1 is an archaic, rather than a classic, CUP pilus. SMF-1 forms thin, zigzag filaments that assemble into defined antiparallel "pili-couples," which further aggregate into thick bundles. These bundles act as robust intercellular tethers, facilitating the rapid cell-to-cell aggregation required for biofilm initiation. Despite high sequence and structural similarity to classic CUP systems, SMF-1 lacks the interfaces required to form a rod-like architecture, suggesting it may represent an evolutionary intermediate between the CUP classes. Finally, we demonstrate that SMF-1 producing bacteria initiate biofilm formation within 24 hours and that flagella can further accelerate this process. Together, these findings uncover a conserved bundling mechanism that promotes bacterial colonization and may contribute to pathogenicity.

microbiology↗

A biofidelic Goat Model of Traumatic Optic Neuropathy with Optic Canal Fracture via Transnasal Endoscopy

Traumatic optic neuropathy (TON) is a major cause of irreversible vision loss following blunt cranial trauma, yet the absence of clinically relevant large animal models that faithfully recapitulate human TON has significantly impeded translational research. Current rodent models do not reproduce optic canal fracture, a key injury mechanism in many patients with TON. Here, we combined high-fidelity finite element analysis (FEA) with iterative engineering to establish a reproducible goat model of TON. We first built a high-resolution human-head finite element model to characterize force transmission to the optic nerve. Across clinically relevant periorbital impacts, stress preferentially concentrated in the intracanalicular segment, reaching a peak force density of approximately 500 N/m2 at 50.6 ms, about fivefold higher than in the intraorbital segment. Simulations further showed that direct optic canal impact reproduced comparable intracanalicular stress with a markedly lower input force: 195 N, compared with 3900 N for periorbital impact. Guided by these insights, we developed transnasal endoscopic impact systems capable of inducing optic canal fractures in goats. TON was confirmed within 24 hours by a characteristic relative afferent pupillary defect (RAPD), and at 1 month post-injury goats (n = 14) exhibited a 10%-20% reduction in ganglion cell complex (GCC) thickness and 40%-65% reductions in flash visual evoked potential (FVEP) and pattern electroretinogram (PERG) amplitude ratios (all P [≤] 0.001), with structural and functional preservation of the fellow eye. This study presents a robust, standardized, and clinically relevant large-animal platform for investigating TON pathophysiology.

neuroscience↗

Lessons learned from manual curation of thousands of gene models in the nematode Pristionchus pacificus

Continuous developments in sequencing technologies have led to the generation of chromosome-scale genome assemblies across the whole tree of life, but our ability to annotate genomes has lacked behind. One major problem consists in the fact that typically not all genes are expressed at detectable levels at any given life stage or environment. Therefore, available transcriptome data needs to be complemented by gene prediction programs and protein homology evidence. However, how to optimally combine these different data types is not well understood. Here, we present a case study, where we community curated gene annotations of the Pristionchus pacificus strain RSC011. By incorporation of new Iso-seq and RNA-seq data and genome-wide screening, we identified and corrected more than 7,500 ([~]24%) gene models. While the improved gene annotation for the RSC011 strain will be useful for the P. pacificus community, our study reveals several gene annotation problems that may affect data from other species. Among these, we identified assembly errors, artificial transcript fusions resulting from overlapping genes and polycistronic RNAs, falsely called open reading frames, and error propagation based on homology data as frequent sources of gene annotation errors. Thus, our findings may be helpful in guiding future efforts to annotate genomes across different taxonomic groups.

genomics↗

Insight into the scaffolding function of USP18 from a high resolution cryo-EM structure of STAT2-USP18-ISG15 ternary complex

USP18 is a primary negative regulator of the type I interferon (IFN-I) signaling which regulates hundreds of IFN-stimulated genes for viral protection and anti-cancer immunity. USP18 plays dual roles in the IFN-I signaling: 1) deubiquitinase enzymatic function which cleaves ISG15 from its substrates and 2) scaffolding function through forming a complex with STAT2 to suppress IFN-I signaling. Targeting the scaffolding function of USP18, instead of its enzyme activity, is crucial for reducing cancer cell fitness and boosting anti-tumor immunity. However, the molecular basis of USP18s scaffolding function remains unclear due to the lack of structural information. Here, using a fusion tag strategy, we captured the transient USP18-STAT2 complex and determined a ternary complex structure of STAT2-USP18-ISG15 at 3.05 [A] resolution by cryogenic electron microscopy (cryo-EM) that delineated detailed USP18-STAT2 interactions. Remarkably, the ternary complex impairs USP18s enzymatic function by STAT2-mediated disruption of its catalytic triad. Structural analysis and mutagenesis identify specific USP18 point mutations, facilitating further investigation into the role of USP18 in IFN-I signaling. Taken together, our findings suggest that USP18s scaffolding function could present an untapped opportunity for cancer therapy.

molecular biology↗

Characterization of the Gut Microbiota and Serum Metabolomics in Patients with Type 2 Diabetes Mellitus and Newly Diagnosed Acute Coronary Syndrome

Biomarkers for the early identification of acute coronary syndrome (ACS) risk remain inadequately investigated, particularly in patients with type 2 diabetes mellitus (T2DM), for whom timely clinical intervention may substantially enhance prognostic outcomes. The gut microbiota and serum metabolites may serve as pivotal mediators in the occurrence and progression of ACS among patients with T2DM, and whether these factors can be used for the precise discrimination of patients with T2DM complicated by ACS remains to be explored. Overall, 76 participants were enrolled (38 patients diagnosed with T2DM complicated by ACS and another 38 with T2DM without ACS). 16S rRNA sequencing combined with untargeted LC-MS metabolomics revealed a dysregulated gut-serum axis in patients with T2DM complicated by ACS: enrichment of proinflammatory microorganisms (Enterococcus spp.), reduction of butyrate producers (Butyricimonas spp.) and concomitant dysregulation of circulating lipid metabolites-upregulation of PC(16:0/9:0 (CHO)) and arachidonic acid alongside downregulation of cholesterol sulfate. By integrating multiomics data and applying various feature selection methods, we subsequently identified six key biomarkers. The final constructed combined model robustly distinguished patients with T2DM complicated by ACS from those with T2DM alone (AUC = 0.983), outperforming the other single omics models. Our study revealed that the gut microbiota and related serum metabolites serve as key mediators in the onset and progression of ACS among patients with T2DM, and demonstrated their potential value as noninvasive biomarkers for the early diagnosis of T2DM complicated by ACS. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSWe combined 16S rRNA sequencing with untargeted LC-MS metabolomics to dissect the gut-serum axis in patients with T2DM complicated by newly diagnosed ACS. We identified distinct gut microbial and serum metabolic signatures that distinguish ACS progression within the T2DM population. A multiomics classifier integrating clinical, microbial, and metabolic variables achieved robust diagnostic performance (AUC = 0.983) and outperformed single omics models. What Are the Clinical Implications?Integrated multiomics biomarkers facilitate the early identification of ACS progression in patients with T2DM, offering novel avenues for precision prevention, dynamic clinical surveillance, and individualized therapeutic strategies. Dysregulations of the gut microbiota and serum metabolome may play an important role in the development and progression of ACS in patients with T2DM.

microbiology↗

FluNexus: a versatile web platform for antigenic prediction and visualization of influenza A viruses

Influenza A viruses continuously undergo antigenic evolution to escape host immunity induced by previous infections or vaccinations, consequently causing seasonal epidemics and occasional pandemics. Antigenic prediction and visualization of influenza A viruses are crucial for precise vaccine strain selection and robust pandemic preparedness. However, a user-friendly online platform for these capabilities remains notably absent, despite widespread demand. Here, we present FluNexus (https://flunexus.com), the first-of-its-kind, one-stop-shop web platform designed to facilitate the prediction and visualization of the antigenic change in emerging variants. FluNexus features a data preprocessing module for hemagglutinin subunit 1 (HA1) and hemagglutination inhibition (HI) data across three major public health threat subtypes (H1, H3 and H5). Meanwhile, FluNexus provides an interactive interface for online antigenic prediction and offers practical guidance for researchers. Most notably, FluNexus offers the visualization of influenza A virus antigenic evolution, providing intuitive insights into its antigenic dynamics. Specially, FluNexus proposes a novel manifold-based method for positioning antigens and antisera, generating accurate antigenic cartographies even with sparse HI data. By alleviating the programming burden on biologists, FluNexus supports more informed decision-making in vaccine strain selection and strengthens surveillance and pandemic preparedness. HighlightsO_LIFluNexus features a data preprocessing module for HA1 and HI data spanning the H1, H3, and H5 subtypes. C_LIO_LIFluNexus facilitates online antigenic prediction utilizing ten state-of-the-art antigenic prediction tools, and offers practical guidance based on a comparative evaluation of their performance. C_LIO_LIFluNexus provides a visualization module for mapping antigenic evolution of influenza A viruses, incorporating a novel manifold-based method for antigenic cartography. C_LI

bioinformatics↗

Spatial mapping of RNA turnover kinetics and regulatory landscapes of mRNA stability in the mammalian brain

Spatial and activity-dependent gene regulation in the mammalian brain requires coordinated control of RNA synthesis and degradation 1,2, yet spatially resolved measurement of RNA turnover kinetics in complex tissues remains technically challenging 3. Here, we present spatial NT-seq, an approach that integrates transgenesis-free metabolic RNA labeling with in situ chemical recoding to spatially co-map RNA abundance and turnover kinetics in the mouse brain. By distinguishing newly synthesized from pre-existing RNAs, this method reveals spatially resolved transcriptional and post-transcriptional responses to electroconvulsive stimulation (ECS), a treatment for refractory depression. We uncover pronounced spatial heterogeneity in RNA turnover, with the dentate gyrus (DG) exhibiting elevated basal RNA turnover and robust ECS-induced responses. These findings reveal a "kinetics scaling" mechanism of coordinated regulation of RNA synthesis and decay, by which DG cells can rapidly remodel their transcript pools in responses to external stimuli or differentiation signals 4,5. Machine learning applied to in vivo RNA kinetics landscapes further identifies sequence features and post-transcriptional regulators underlying region-and cell-type-specific control of mRNA stability. Together, this integrated experimental and computational framework, in vivo Timescope, enables transcriptome-wide mapping of RNA turnover kinetics and the regulatory architecture of RNA stability across spatial and cellular contexts, providing new insights into the spatiotemporal regulation of RNA dynamics in brain function and disease.

genomics↗

Afterimages drive a shared visual motion reversal illusion in Drosophila

Illusions expose core computations in perception. In one visual apparent-motion illusion, perceptual direction is reversed when phase-shifted gratings are interleaved with uniform frames. Here, we demonstrate that Drosophila exhibits the same direction reversal reported in mammals. Combining behavior, targeted silencing, two-photon imaging, and modeling, we localize the origin of this illusion to elementary motion pathways. Silencing direction-selective T4/T5 neurons abolishes the reversal, and recordings reveal that downstream wide-field neurons invert their directional preference as interleave duration increases. Replacing periodic gratings with random binary patterns preserves the reversal, implicating afterimages rather than spatial periodicity. Imaging neurons upstream of T4/T5 shows signatures of an afterimage, whose emergence depends on interleave luminance. Critically, dark interleaves suppress afterimages and eliminate both the neural and behavioral reversal, whereas light interleaves preserve or enhance it. Thus, afterimages are central to this shared illusion and explain a deficiency of canonical motion-energy accounts. These results link a classic apparent-motion phenomenon to identified circuit elements and reveal a simple stimulus manipulation that switches an illusion on and off.

neuroscience↗

Programmed Double-stranded RNA Formation Enables Meiotic Stage Transitions

Cell fate transitions rely on extensive transcriptional activation mediated by transcription factors, yet the equally important processes that ensure the selective removal of pre-existing mRNAs remain elusive. We uncover widespread formation of double-stranded RNA (dsRNA) during early-to-middle meiosis using quantitative RNA structure analysis, and validate hundreds of natural antisense transcripts (NATs) through long-read sequencing. These NATs are induced by meiosis-specific transcription factors, including Ndt80p, and pair with sense mRNAs to drive cytoplasmic aggregation of the resulting dsRNAs. These dsRNA aggregates are subsequently transported to the vacuole for clearance, likely via autophagy. This pathway selectively eliminates mRNAs before metaphase I, including NDJ1, which encodes a meiotic cohesion protein that would otherwise block chromosome segregation. Our study reveals a physiological role for large-scale dsRNA formation, and highlights a simple but powerful model: the same transcription factors that activate mRNAs required for a specific developmental stage also program the synthesis of NATs that promote removal of transcripts from the preceding stage, thereby driving bidirectional transcriptome reprogramming.

cell biology↗

RNA Structure Coordinates Translation Across the Meiotic Program

mRNA structure clearly modulates translation efficiency for individual transcripts, yet its role in coordinating translation across many transcripts remains poorly defined. Meiosis offers a compelling test case, involving large-scale gene expression changes coordinated across hundreds of mRNAs under conditions where transcription is constrained by chromosome condensation. We profiled mRNA structures across yeast meiosis, generating a high-resolution structurome encompassing ~70% of annotated mRNAs, including multi-time-point measurements for 2,084 transcripts. Transcripts upregulated during meiosis generally adopt flexible structures that enhance translation, whereas mRNAs with complex 5' UTR and coding-region structures show suppressed translation, indicating that RNA structure globally shapes meiotic translation. We further observed a high-low-high oscillation in cytoplasmic RNA helicase levels across meiosis. Together, these findings support a model in which RNA structure and helicase expression act jointly to program stage-specific translation of hundreds of mRNAs, with highly structured transcripts selectively translated at late stages. Consistent with this model, disrupting the structure of the abundant transcript CCW22, or altering Ded1p helicase levels, impaired meiotic progression in an RNA structure-dependent manner. Our study reveals that the concerted action of RNA structure and helicases coordinates cell-wide translation dynamics to meet stage-specific demands, especially critical when transcription is limited during meiotic divisions.

genomics↗

Co-option of ILF2/3 in primates restrains Alu hyper-editing to enable cell fate transitions

Understanding human specific mechanisms of cell fate control is essential for advancing developmental biology and regenerative medicine. Here, we identify the ILF2/3 complex as a critical regulator of primate cell fate transitions. Using genetically and epigenetically engineered gastruloids and adult stem cells, we show that ILF2/3 is required for gastrulation in primates but not mice, and for differentiation of adult progenitor cells. Mechanistically, ILF2/3 directly binds Alu elements in chromatin-associated RNAs and shields them from ADAR1-mediated adenosine-to-inosine (A-to-I) editing. Acute ILF2/3 degradation increases A-to-I editing at Alu elements, but not murine retrotransposons, leading to aberrant splicing and nonsense-mediated decay of transcripts encoding key chromatin regulators in primate cells. This in turn destabilizes the epigenetic landscape and blocks lineage commitment across all three germ layers. Re-expression of correctly spliced chromatin regulators rescues differentiation defects in ILF2/3-deficient cells, functionally linking Alu editing control to chromatin regulation and cell fate. These findings define an evolutionary mechanism that restrains retrotransposon-associated RNA editing to preserve proteome integrity and enable primate-specific developmental programs.

genetics↗

Glucokinase links metabolism and lineage plasticity in neuroendocrine prostate cancer via interaction with AKT1

Cancer cells frequently rewire their metabolism to sustain growth and survival under stress. Despite the critical role of metabolic adaptation in tumorigenesis, how specific metabolic enzymes regulate lineage plasticity remains unclear. Here, through FDG-PET imaging and transcriptomic analyses, we reveal markedly elevated glucose uptake in neuroendocrine prostate cancer (NEPC) and identify glucokinase (GCK) as a MYCN-induced metabolic enzyme. Beyond its metabolic role, GCK is indispensable for maintaining the neuroendocrine lineage of prostate cancer cells by establishing a functional circuit with AKT1 through reciprocal regulation--AKT1 binds and phosphorylates GCK at S373, whereas GCK phosphorylates AKT1 at S473. Pharmacological disruption of this AKT1-GCK axis suppresses tumor growth in NEPC mouse models and patient-derived xenografts. Altogether, our findings uncover both the metabolic and noncanonical kinase functions of GCK and establish the AKT1-GCK axis as a key link between metabolic reprogramming and neuroendocrine lineage transition in prostate cancer.

cancer biology↗

Autistic Children Show Reduced Activity in Left Superior Temporal Cortex in Response to Social-emotional Meaning in Language

Autistic children often differ from non-autistic peers in social interaction, emotional processing, and language communication. While the neural differences between autistic and non-autistic children in processing paralinguistic social-emotional cues, such as emotional prosody, are well-documented, much less is known about how the brain processes the social-emotional meaning carried by the language content itself. In non-autistic adults, the left superior temporal sulcus (STS) and adjacent gyrus show a social-emotional bias, responding more strongly to social-emotional content than to content describing inanimate objects. We investigated whether this bias is present in children and whether it is altered in autistic children. We recruited 78 right-handed children who underwent functional magnetic resonance imaging (fMRI) scanning while listening to sentences describing either people in emotional situations (social-emotional sentences) or non-human objects, events, or concepts (object sentences). After excluding those with excessive head motion, we analyzed data from 58 of them (37 autistic and 21 non-autistic; mean age 10 years). Across the sample as a whole, the left STS responded more strongly to social-emotional sentences than to object sentences, indicating that this social-emotional bias is already present in childhood. Importantly, this bias was reduced in autistic children compared to non-autistic controls, whereas no group difference was observed in general auditory or lexico-syntactic processing. This reduced activity in the left STS in response to social-emotional semantics may contribute to autistic children's social communication challenges.

neuroscience↗

mRNAbow: A versatile gene expression system for multiplexed fluorescent imaging using optimized in vitro transcribed mRNA

Messenger RNA (mRNA) transfection enables rapid, transient protein expression without nuclear entry, providing a powerful alternative to DNA or viral delivery in post-mitotic and otherwise difficult-to-transfect cells. Although in vitro transcribed (IVT) mRNAs have revolutionized therapeutic applications, their adoption in experimental biology remains limited by challenges in synthesis, variability across cell types, and concerns about cytotoxicity. Here, we define design principles that maximize IVT mRNA performance across diverse cellular and organismal systems. Through systematic comparison of capping strategies and base modifications, including N1-methyl-pseudouridine, 5-methylcytidine, and 5-methoxyuridine, we identify modifications that enhance translation while minimizing activation of cellular stress responses. Optimized transcripts drive robust protein expression within four hours, persist for up to one week, and support multiplexed expression of structurally and functionally distinct proteins in mammalian cells, including cancer cell lines, iPSC-derived systems, primary cells, and organoids, as well as in vivo in zebrafish embryos and in less genetically tractable models such as Danionella cerebrum and sea urchin embryos. To further expand accessibility for community use, we developed mRNAbow, a platform for generating low-toxicity mRNAs encoding organelle-targeted fluorescent proteins and biosensors for multiplex imaging, with corresponding plasmids made publicly available. Together, these advances establish a generalizable framework for IVT mRNA design and expand experimental access to synthetic mRNA technologies for dissecting cellular architecture and dynamics.

cell biology↗

The inactivation of DHHC7 in mouse liver promotes diet-induced obesity through a hepatic Prg4-GPR146 axis

The liver secretes hepatokines that coordinate whole-body metabolism. Posttranslational lipidation of signaling proteins by DHHC palmitoyltransferases controls membrane targeting and signaling, yet the role of hepatic palmitoylation in systemic metabolic regulation is largely unexplored. Using an inducible, liver-specific DHHC7 knockout (D7LKO) mouse, we report that loss of DHHC7 in hepatocytes potentiates adenylyl cyclase-PKA-CREB signaling through reducing palmitoylation of inhibitory G protein subunit (Gi), leading to transcriptional elevation and secretion of proteoglycan 4 (Prg4). Elevated circulating Prg4 acts on adipocytes by binding GPR146 via Prg4s N-terminal SMB domain, suppressing adipocyte PKA substrate phosphorylation and hormone-sensitive lipase (HSL) Ser563 phosphorylation, thereby impairing lipolysis. Under high-fat diet (HFD) feeding, D7LKO mice and mice with adenoviral hepatic Prg4 overexpression develop pronounced obesity characterized by increasing brown, subcutaneous, and visceral fat mass and adipocyte hypertrophy; strikingly, these animals show little impairment in glucose tolerance or circulating triglycerides but display elevated plasma cholesterol. Conditioned medium containing Prg4 recapitulates suppression of adipocyte HSL phosphorylation in vitro, and SMB-deleted Prg4 fails to bind GPR146 or inhibit HSL phosphorylation. Our findings define a liver palmitoylation- hepatokine axis that controls adipose lipolysis and predisposes to diet-induced fat accumulation, establishing Prg4-GPR146 as a mechanistic link between hepatic signaling and adipose energy mobilization.

physiology↗

The Hippo Pathway Regulates Corneal Endothelial Regeneration

Corneal endothelial cells (CECs) have limited regeneration capacity in primates while display a potent restorative capability in some species such as rodents after wounding. The mechanism which determines the regenerative capability of CECs remains poorly understood. Here, we identify that the Hippo signaling pathway is inhibited and the downstream effector YAP is activated during CEC wound healing in rabbit and mouse. Knockdown of Yap1 and pharmacological inhibition of YAP suppresses CECs wound healing in rodents in both in vitro and in vivo models. XMU-MP-1, a specific small molecular inhibitor for Hippo signaling pathway, can promote the corneal endothelial regeneration in rodents and corneal endothelial proliferation in cultured primate CECs, as well as in vivo non-human primate CEC wounding model. These findings suggest that Hippo pathway serves as a conserved signal to regulate corneal endothelial regeneration among various species, providing a novel target for non-invasive treatment of corneal endothelium decompensation.

cell biology↗

A novel dephosphorylation peptide inhibits 17β-HSD1 enzyme activity in ovarian granulosa cells and breast cancer cells

Estradiol (E2), a pivotal mammalian reproductive hormone, is closely associated with estrogen-dependent diseases. 17{beta}-hydroxysteroid dehydrogenase type 1 (17{beta}-HSD1), a critical E2 synthesis enzyme, has been understudied for its post-translational regulation-despite its potential as a therapeutic target, no clinically approved inhibitors are currently available. In our investigation of porcine follicular atresia mechanisms, we identified five differentially phosphorylated residues in 17{beta}-HSD1. Using in vitro site-directed mutagenesis and transgenic mouse models carrying point mutations, we established that Ser30 and Ser274 are critical phosphorylation sites that robustly modulate 17{beta}-HSD1 enzymatic activity. We further demonstrated that activin A and insulin-like growth factor 1 (IGF-1) enhance 17{beta}-HSD1 activity by promoting its phosphorylation at these two sites. To target these regulatory residues, we designed and synthesized cell-penetrating peptides (CPPs) that specifically suppress 17{beta}-HSD1 phosphorylation. Functional assays conclusively demonstrated that these CPPs significantly suppressed 17{beta}-HSD1 activity in vitro. Notably, they also inhibited the proliferation, migration and invasion of MCF-7 cells, as well as tumor growth in a mouse model of breast cancer. Our study provides novel mechanistic insights into the regulation of 17{beta}-HSD1 and E2 synthesis, addressing a critical gap in steroid hormone biology. The identification of Ser30/Ser274 as functional phosphorylation sites and the development of CPP-based inhibitors offer both theoretical advances and translational potential, opening new avenues for the treatment of estrogen-dependent breast cancer.

cell biology↗